1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Mellanox BlueField I2C bus driver
4  *
5  *  Copyright (C) 2020 Mellanox Technologies, Ltd.
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/bitfield.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/interrupt.h>
13 #include <linux/i2c.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/of_device.h>
19 #include <linux/platform_device.h>
20 #include <linux/string.h>
21 
22 /* Defines what functionality is present. */
23 #define MLXBF_I2C_FUNC_SMBUS_BLOCK \
24 	(I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL)
25 
26 #define MLXBF_I2C_FUNC_SMBUS_DEFAULT \
27 	(I2C_FUNC_SMBUS_BYTE      | I2C_FUNC_SMBUS_BYTE_DATA | \
28 	 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK | \
29 	 I2C_FUNC_SMBUS_PROC_CALL)
30 
31 #define MLXBF_I2C_FUNC_ALL \
32 	(MLXBF_I2C_FUNC_SMBUS_DEFAULT | MLXBF_I2C_FUNC_SMBUS_BLOCK | \
33 	 I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SLAVE)
34 
35 /* Shared resources info in BlueField platforms. */
36 
37 #define MLXBF_I2C_COALESCE_TYU_ADDR    0x02801300
38 #define MLXBF_I2C_COALESCE_TYU_SIZE    0x010
39 
40 #define MLXBF_I2C_GPIO_TYU_ADDR        0x02802000
41 #define MLXBF_I2C_GPIO_TYU_SIZE        0x100
42 
43 #define MLXBF_I2C_COREPLL_TYU_ADDR     0x02800358
44 #define MLXBF_I2C_COREPLL_TYU_SIZE     0x008
45 
46 #define MLXBF_I2C_COREPLL_YU_ADDR      0x02800c30
47 #define MLXBF_I2C_COREPLL_YU_SIZE      0x00c
48 
49 #define MLXBF_I2C_COREPLL_RSH_YU_ADDR  0x13409824
50 #define MLXBF_I2C_COREPLL_RSH_YU_SIZE  0x00c
51 
52 #define MLXBF_I2C_SHARED_RES_MAX       3
53 
54 /*
55  * Note that the following SMBus, CAUSE, GPIO and PLL register addresses
56  * refer to their respective offsets relative to the corresponding
57  * memory-mapped region whose addresses are specified in either the DT or
58  * the ACPI tables or above.
59  */
60 
61 /*
62  * SMBus Master core clock frequency. Timing configurations are
63  * strongly dependent on the core clock frequency of the SMBus
64  * Master. Default value is set to 400MHz.
65  */
66 #define MLXBF_I2C_TYU_PLL_OUT_FREQ  (400 * 1000 * 1000)
67 /* Reference clock for Bluefield - 156 MHz. */
68 #define MLXBF_I2C_PLL_IN_FREQ       156250000ULL
69 
70 /* Constant used to determine the PLL frequency. */
71 #define MLNXBF_I2C_COREPLL_CONST    16384ULL
72 
73 #define MLXBF_I2C_FREQUENCY_1GHZ  1000000000ULL
74 
75 /* PLL registers. */
76 #define MLXBF_I2C_CORE_PLL_REG1         0x4
77 #define MLXBF_I2C_CORE_PLL_REG2         0x8
78 
79 /* OR cause register. */
80 #define MLXBF_I2C_CAUSE_OR_EVTEN0    0x14
81 #define MLXBF_I2C_CAUSE_OR_CLEAR     0x18
82 
83 /* Arbiter Cause Register. */
84 #define MLXBF_I2C_CAUSE_ARBITER      0x1c
85 
86 /*
87  * Cause Status flags. Note that those bits might be considered
88  * as interrupt enabled bits.
89  */
90 
91 /* Transaction ended with STOP. */
92 #define MLXBF_I2C_CAUSE_TRANSACTION_ENDED  BIT(0)
93 /* Master arbitration lost. */
94 #define MLXBF_I2C_CAUSE_M_ARBITRATION_LOST BIT(1)
95 /* Unexpected start detected. */
96 #define MLXBF_I2C_CAUSE_UNEXPECTED_START   BIT(2)
97 /* Unexpected stop detected. */
98 #define MLXBF_I2C_CAUSE_UNEXPECTED_STOP    BIT(3)
99 /* Wait for transfer continuation. */
100 #define MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA   BIT(4)
101 /* Failed to generate STOP. */
102 #define MLXBF_I2C_CAUSE_PUT_STOP_FAILED    BIT(5)
103 /* Failed to generate START. */
104 #define MLXBF_I2C_CAUSE_PUT_START_FAILED   BIT(6)
105 /* Clock toggle completed. */
106 #define MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE    BIT(7)
107 /* Transfer timeout occurred. */
108 #define MLXBF_I2C_CAUSE_M_FW_TIMEOUT       BIT(8)
109 /* Master busy bit reset. */
110 #define MLXBF_I2C_CAUSE_M_GW_BUSY_FALL     BIT(9)
111 
112 #define MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK     GENMASK(9, 0)
113 
114 #define MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR \
115 	(MLXBF_I2C_CAUSE_M_ARBITRATION_LOST | \
116 	 MLXBF_I2C_CAUSE_UNEXPECTED_START | \
117 	 MLXBF_I2C_CAUSE_UNEXPECTED_STOP | \
118 	 MLXBF_I2C_CAUSE_PUT_STOP_FAILED | \
119 	 MLXBF_I2C_CAUSE_PUT_START_FAILED | \
120 	 MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE | \
121 	 MLXBF_I2C_CAUSE_M_FW_TIMEOUT)
122 
123 /*
124  * Slave cause status flags. Note that those bits might be considered
125  * as interrupt enabled bits.
126  */
127 
128 /* Write transaction received successfully. */
129 #define MLXBF_I2C_CAUSE_WRITE_SUCCESS         BIT(0)
130 /* Read transaction received, waiting for response. */
131 #define MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE BIT(13)
132 /* Slave busy bit reset. */
133 #define MLXBF_I2C_CAUSE_S_GW_BUSY_FALL        BIT(18)
134 
135 /* Cause coalesce registers. */
136 #define MLXBF_I2C_CAUSE_COALESCE_0        0x00
137 
138 #define MLXBF_I2C_CAUSE_TYU_SLAVE_BIT   3
139 #define MLXBF_I2C_CAUSE_YU_SLAVE_BIT    1
140 
141 /* Functional enable register. */
142 #define MLXBF_I2C_GPIO_0_FUNC_EN_0    0x28
143 /* Force OE enable register. */
144 #define MLXBF_I2C_GPIO_0_FORCE_OE_EN  0x30
145 /*
146  * Note that Smbus GWs are on GPIOs 30:25. Two pins are used to control
147  * SDA/SCL lines:
148  *
149  *  SMBUS GW0 -> bits[26:25]
150  *  SMBUS GW1 -> bits[28:27]
151  *  SMBUS GW2 -> bits[30:29]
152  */
153 #define MLXBF_I2C_GPIO_SMBUS_GW_PINS(num) (25 + ((num) << 1))
154 
155 /* Note that gw_id can be 0,1 or 2. */
156 #define MLXBF_I2C_GPIO_SMBUS_GW_MASK(num) \
157 	(0xffffffff & (~(0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num))))
158 
159 #define MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(num, val) \
160 	((val) & MLXBF_I2C_GPIO_SMBUS_GW_MASK(num))
161 
162 #define MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(num, val) \
163 	((val) | (0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num)))
164 
165 /*
166  * Defines SMBus operating frequency and core clock frequency.
167  * According to ADB files, default values are compliant to 100KHz SMBus
168  * @ 400MHz core clock. The driver should be able to calculate core
169  * frequency based on PLL parameters.
170  */
171 #define MLXBF_I2C_COREPLL_FREQ          MLXBF_I2C_TYU_PLL_OUT_FREQ
172 
173 /* Core PLL TYU configuration. */
174 #define MLXBF_I2C_COREPLL_CORE_F_TYU_MASK   GENMASK(15, 3)
175 #define MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK  GENMASK(19, 16)
176 #define MLXBF_I2C_COREPLL_CORE_R_TYU_MASK   GENMASK(25, 20)
177 
178 /* Core PLL YU configuration. */
179 #define MLXBF_I2C_COREPLL_CORE_F_YU_MASK    GENMASK(25, 0)
180 #define MLXBF_I2C_COREPLL_CORE_OD_YU_MASK   GENMASK(3, 0)
181 #define MLXBF_I2C_COREPLL_CORE_R_YU_MASK    GENMASK(31, 26)
182 
183 /* SMBus timing parameters. */
184 #define MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH    0x00
185 #define MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE     0x04
186 #define MLXBF_I2C_SMBUS_TIMER_THOLD               0x08
187 #define MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP   0x0c
188 #define MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA         0x10
189 #define MLXBF_I2C_SMBUS_THIGH_MAX_TBUF            0x14
190 #define MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT           0x18
191 
192 #define MLXBF_I2C_SHIFT_0   0
193 #define MLXBF_I2C_SHIFT_8   8
194 #define MLXBF_I2C_SHIFT_16  16
195 #define MLXBF_I2C_SHIFT_24  24
196 
197 #define MLXBF_I2C_MASK_8    GENMASK(7, 0)
198 #define MLXBF_I2C_MASK_16   GENMASK(15, 0)
199 
200 #define MLXBF_I2C_MST_ADDR_OFFSET         0x200
201 
202 /* SMBus Master GW. */
203 #define MLXBF_I2C_SMBUS_MASTER_GW         0x0
204 /* Number of bytes received and sent. */
205 #define MLXBF_I2C_YU_SMBUS_RS_BYTES       0x100
206 #define MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES   0x10c
207 /* Packet error check (PEC) value. */
208 #define MLXBF_I2C_SMBUS_MASTER_PEC        0x104
209 /* Status bits (ACK/NACK/FW Timeout). */
210 #define MLXBF_I2C_SMBUS_MASTER_STATUS     0x108
211 /* SMbus Master Finite State Machine. */
212 #define MLXBF_I2C_YU_SMBUS_MASTER_FSM     0x110
213 #define MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM 0x100
214 
215 /* SMBus master GW control bits offset in MLXBF_I2C_SMBUS_MASTER_GW[31:3]. */
216 #define MLXBF_I2C_MASTER_LOCK_BIT         BIT(31) /* Lock bit. */
217 #define MLXBF_I2C_MASTER_BUSY_BIT         BIT(30) /* Busy bit. */
218 #define MLXBF_I2C_MASTER_START_BIT        BIT(29) /* Control start. */
219 #define MLXBF_I2C_MASTER_CTL_WRITE_BIT    BIT(28) /* Control write phase. */
220 #define MLXBF_I2C_MASTER_CTL_READ_BIT     BIT(19) /* Control read phase. */
221 #define MLXBF_I2C_MASTER_STOP_BIT         BIT(3)  /* Control stop. */
222 
223 #define MLXBF_I2C_MASTER_ENABLE \
224 	(MLXBF_I2C_MASTER_LOCK_BIT | MLXBF_I2C_MASTER_BUSY_BIT | \
225 	 MLXBF_I2C_MASTER_START_BIT | MLXBF_I2C_MASTER_STOP_BIT)
226 
227 #define MLXBF_I2C_MASTER_ENABLE_WRITE \
228 	(MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_WRITE_BIT)
229 
230 #define MLXBF_I2C_MASTER_ENABLE_READ \
231 	(MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_READ_BIT)
232 
233 #define MLXBF_I2C_MASTER_WRITE_SHIFT      21 /* Control write bytes */
234 #define MLXBF_I2C_MASTER_SEND_PEC_SHIFT   20 /* Send PEC byte when set to 1 */
235 #define MLXBF_I2C_MASTER_PARSE_EXP_SHIFT  11 /* Control parse expected bytes */
236 #define MLXBF_I2C_MASTER_SLV_ADDR_SHIFT   12 /* Slave address */
237 #define MLXBF_I2C_MASTER_READ_SHIFT       4  /* Control read bytes */
238 
239 /* SMBus master GW Data descriptor. */
240 #define MLXBF_I2C_MASTER_DATA_DESC_ADDR   0x80
241 #define MLXBF_I2C_MASTER_DATA_DESC_SIZE   0x80 /* Size in bytes. */
242 
243 /* Maximum bytes to read/write per SMBus transaction. */
244 #define MLXBF_I2C_MASTER_DATA_R_LENGTH  MLXBF_I2C_MASTER_DATA_DESC_SIZE
245 #define MLXBF_I2C_MASTER_DATA_W_LENGTH (MLXBF_I2C_MASTER_DATA_DESC_SIZE - 1)
246 
247 /* All bytes were transmitted. */
248 #define MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE      BIT(0)
249 /* NACK received. */
250 #define MLXBF_I2C_SMBUS_STATUS_NACK_RCV           BIT(1)
251 /* Slave's byte count >128 bytes. */
252 #define MLXBF_I2C_SMBUS_STATUS_READ_ERR           BIT(2)
253 /* Timeout occurred. */
254 #define MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT         BIT(3)
255 
256 #define MLXBF_I2C_SMBUS_MASTER_STATUS_MASK        GENMASK(3, 0)
257 
258 #define MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR \
259 	(MLXBF_I2C_SMBUS_STATUS_NACK_RCV | \
260 	 MLXBF_I2C_SMBUS_STATUS_READ_ERR | \
261 	 MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT)
262 
263 #define MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK      BIT(31)
264 #define MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK  BIT(15)
265 
266 #define MLXBF_I2C_SLV_ADDR_OFFSET             0x400
267 
268 /* SMBus slave GW. */
269 #define MLXBF_I2C_SMBUS_SLAVE_GW              0x0
270 /* Number of bytes received and sent from/to master. */
271 #define MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES 0x100
272 /* Packet error check (PEC) value. */
273 #define MLXBF_I2C_SMBUS_SLAVE_PEC             0x104
274 /* SMBus slave Finite State Machine (FSM). */
275 #define MLXBF_I2C_SMBUS_SLAVE_FSM             0x110
276 /*
277  * Should be set when all raised causes handled, and cleared by HW on
278  * every new cause.
279  */
280 #define MLXBF_I2C_SMBUS_SLAVE_READY           0x12c
281 
282 /* SMBus slave GW control bits offset in MLXBF_I2C_SMBUS_SLAVE_GW[31:19]. */
283 #define MLXBF_I2C_SLAVE_BUSY_BIT         BIT(30) /* Busy bit. */
284 #define MLXBF_I2C_SLAVE_WRITE_BIT        BIT(29) /* Control write enable. */
285 
286 #define MLXBF_I2C_SLAVE_ENABLE \
287 	(MLXBF_I2C_SLAVE_BUSY_BIT | MLXBF_I2C_SLAVE_WRITE_BIT)
288 
289 #define MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT 22 /* Number of bytes to write. */
290 #define MLXBF_I2C_SLAVE_SEND_PEC_SHIFT    21 /* Send PEC byte shift. */
291 
292 /* SMBus slave GW Data descriptor. */
293 #define MLXBF_I2C_SLAVE_DATA_DESC_ADDR   0x80
294 #define MLXBF_I2C_SLAVE_DATA_DESC_SIZE   0x80 /* Size in bytes. */
295 
296 /* SMbus slave configuration registers. */
297 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG        0x114
298 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT        16
299 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT     BIT(7)
300 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK       GENMASK(6, 0)
301 
302 /*
303  * Timeout is given in microsends. Note also that timeout handling is not
304  * exact.
305  */
306 #define MLXBF_I2C_SMBUS_TIMEOUT   (300 * 1000) /* 300ms */
307 #define MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT (300 * 1000) /* 300ms */
308 
309 /* Polling frequency in microseconds. */
310 #define MLXBF_I2C_POLL_FREQ_IN_USEC        200
311 
312 #define MLXBF_I2C_SMBUS_OP_CNT_1   1
313 #define MLXBF_I2C_SMBUS_OP_CNT_2   2
314 #define MLXBF_I2C_SMBUS_OP_CNT_3   3
315 #define MLXBF_I2C_SMBUS_MAX_OP_CNT MLXBF_I2C_SMBUS_OP_CNT_3
316 
317 /* Helper macro to define an I2C resource parameters. */
318 #define MLXBF_I2C_RES_PARAMS(addr, size, str) \
319 	{ \
320 		.start = (addr), \
321 		.end = (addr) + (size) - 1, \
322 		.name = (str) \
323 	}
324 
325 enum {
326 	MLXBF_I2C_TIMING_100KHZ = 100000,
327 	MLXBF_I2C_TIMING_400KHZ = 400000,
328 	MLXBF_I2C_TIMING_1000KHZ = 1000000,
329 };
330 
331 enum {
332 	MLXBF_I2C_F_READ = BIT(0),
333 	MLXBF_I2C_F_WRITE = BIT(1),
334 	MLXBF_I2C_F_NORESTART = BIT(3),
335 	MLXBF_I2C_F_SMBUS_OPERATION = BIT(4),
336 	MLXBF_I2C_F_SMBUS_BLOCK = BIT(5),
337 	MLXBF_I2C_F_SMBUS_PEC = BIT(6),
338 	MLXBF_I2C_F_SMBUS_PROCESS_CALL = BIT(7),
339 };
340 
341 /* Mellanox BlueField chip type. */
342 enum mlxbf_i2c_chip_type {
343 	MLXBF_I2C_CHIP_TYPE_1, /* Mellanox BlueField-1 chip. */
344 	MLXBF_I2C_CHIP_TYPE_2, /* Mellanox BlueField-2 chip. */
345 	MLXBF_I2C_CHIP_TYPE_3 /* Mellanox BlueField-3 chip. */
346 };
347 
348 /* List of chip resources that are being accessed by the driver. */
349 enum {
350 	MLXBF_I2C_SMBUS_RES,
351 	MLXBF_I2C_MST_CAUSE_RES,
352 	MLXBF_I2C_SLV_CAUSE_RES,
353 	MLXBF_I2C_COALESCE_RES,
354 	MLXBF_I2C_SMBUS_TIMER_RES,
355 	MLXBF_I2C_SMBUS_MST_RES,
356 	MLXBF_I2C_SMBUS_SLV_RES,
357 	MLXBF_I2C_COREPLL_RES,
358 	MLXBF_I2C_GPIO_RES,
359 	MLXBF_I2C_END_RES
360 };
361 
362 /* Encapsulates timing parameters. */
363 struct mlxbf_i2c_timings {
364 	u16 scl_high;		/* Clock high period. */
365 	u16 scl_low;		/* Clock low period. */
366 	u8 sda_rise;		/* Data rise time. */
367 	u8 sda_fall;		/* Data fall time. */
368 	u8 scl_rise;		/* Clock rise time. */
369 	u8 scl_fall;		/* Clock fall time. */
370 	u16 hold_start;		/* Hold time after (REPEATED) START. */
371 	u16 hold_data;		/* Data hold time. */
372 	u16 setup_start;	/* REPEATED START condition setup time. */
373 	u16 setup_stop;		/* STOP condition setup time. */
374 	u16 setup_data;		/* Data setup time. */
375 	u16 pad;		/* Padding. */
376 	u16 buf;		/* Bus free time between STOP and START. */
377 	u16 thigh_max;		/* Thigh max. */
378 	u32 timeout;		/* Detect clock low timeout. */
379 };
380 
381 struct mlxbf_i2c_smbus_operation {
382 	u32 flags;
383 	u32 length; /* Buffer length in bytes. */
384 	u8 *buffer;
385 };
386 
387 struct mlxbf_i2c_smbus_request {
388 	u8 slave;
389 	u8 operation_cnt;
390 	struct mlxbf_i2c_smbus_operation operation[MLXBF_I2C_SMBUS_MAX_OP_CNT];
391 };
392 
393 struct mlxbf_i2c_resource {
394 	void __iomem *io;
395 	struct resource *params;
396 	struct mutex *lock; /* Mutex to protect mlxbf_i2c_resource. */
397 	u8 type;
398 };
399 
400 struct mlxbf_i2c_chip_info {
401 	enum mlxbf_i2c_chip_type type;
402 	/* Chip shared resources that are being used by the I2C controller. */
403 	struct mlxbf_i2c_resource *shared_res[MLXBF_I2C_SHARED_RES_MAX];
404 
405 	/* Callback to calculate the core PLL frequency. */
406 	u64 (*calculate_freq)(struct mlxbf_i2c_resource *corepll_res);
407 
408 	/* Registers' address offset */
409 	u32 smbus_master_rs_bytes_off;
410 	u32 smbus_master_fsm_off;
411 };
412 
413 struct mlxbf_i2c_priv {
414 	const struct mlxbf_i2c_chip_info *chip;
415 	struct i2c_adapter adap;
416 	struct mlxbf_i2c_resource *smbus;
417 	struct mlxbf_i2c_resource *timer;
418 	struct mlxbf_i2c_resource *mst;
419 	struct mlxbf_i2c_resource *slv;
420 	struct mlxbf_i2c_resource *mst_cause;
421 	struct mlxbf_i2c_resource *slv_cause;
422 	struct mlxbf_i2c_resource *coalesce;
423 	u64 frequency; /* Core frequency in Hz. */
424 	int bus; /* Physical bus identifier. */
425 	int irq;
426 	struct i2c_client *slave[MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT];
427 	u32 resource_version;
428 };
429 
430 /* Core PLL frequency. */
431 static u64 mlxbf_i2c_corepll_frequency;
432 
433 static struct resource mlxbf_i2c_coalesce_tyu_params =
434 		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COALESCE_TYU_ADDR,
435 				     MLXBF_I2C_COALESCE_TYU_SIZE,
436 				     "COALESCE_MEM");
437 static struct resource mlxbf_i2c_corepll_tyu_params =
438 		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_TYU_ADDR,
439 				     MLXBF_I2C_COREPLL_TYU_SIZE,
440 				     "COREPLL_MEM");
441 static struct resource mlxbf_i2c_corepll_yu_params =
442 		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_YU_ADDR,
443 				     MLXBF_I2C_COREPLL_YU_SIZE,
444 				     "COREPLL_MEM");
445 static struct resource mlxbf_i2c_corepll_rsh_yu_params =
446 		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_RSH_YU_ADDR,
447 				     MLXBF_I2C_COREPLL_RSH_YU_SIZE,
448 				     "COREPLL_MEM");
449 static struct resource mlxbf_i2c_gpio_tyu_params =
450 		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_GPIO_TYU_ADDR,
451 				     MLXBF_I2C_GPIO_TYU_SIZE,
452 				     "GPIO_MEM");
453 
454 static struct mutex mlxbf_i2c_coalesce_lock;
455 static struct mutex mlxbf_i2c_corepll_lock;
456 static struct mutex mlxbf_i2c_gpio_lock;
457 
458 static struct mlxbf_i2c_resource mlxbf_i2c_coalesce_res[] = {
459 	[MLXBF_I2C_CHIP_TYPE_1] = {
460 		.params = &mlxbf_i2c_coalesce_tyu_params,
461 		.lock = &mlxbf_i2c_coalesce_lock,
462 		.type = MLXBF_I2C_COALESCE_RES
463 	},
464 	{}
465 };
466 
467 static struct mlxbf_i2c_resource mlxbf_i2c_corepll_res[] = {
468 	[MLXBF_I2C_CHIP_TYPE_1] = {
469 		.params = &mlxbf_i2c_corepll_tyu_params,
470 		.lock = &mlxbf_i2c_corepll_lock,
471 		.type = MLXBF_I2C_COREPLL_RES
472 	},
473 	[MLXBF_I2C_CHIP_TYPE_2] = {
474 		.params = &mlxbf_i2c_corepll_yu_params,
475 		.lock = &mlxbf_i2c_corepll_lock,
476 		.type = MLXBF_I2C_COREPLL_RES,
477 	},
478 	[MLXBF_I2C_CHIP_TYPE_3] = {
479 		.params = &mlxbf_i2c_corepll_rsh_yu_params,
480 		.lock = &mlxbf_i2c_corepll_lock,
481 		.type = MLXBF_I2C_COREPLL_RES,
482 	}
483 };
484 
485 static struct mlxbf_i2c_resource mlxbf_i2c_gpio_res[] = {
486 	[MLXBF_I2C_CHIP_TYPE_1] = {
487 		.params = &mlxbf_i2c_gpio_tyu_params,
488 		.lock = &mlxbf_i2c_gpio_lock,
489 		.type = MLXBF_I2C_GPIO_RES
490 	},
491 	{}
492 };
493 
494 static u8 mlxbf_i2c_bus_count;
495 
496 static struct mutex mlxbf_i2c_bus_lock;
497 
498 /*
499  * Function to poll a set of bits at a specific address; it checks whether
500  * the bits are equal to zero when eq_zero is set to 'true', and not equal
501  * to zero when eq_zero is set to 'false'.
502  * Note that the timeout is given in microseconds.
503  */
mlxbf_i2c_poll(void __iomem * io,u32 addr,u32 mask,bool eq_zero,u32 timeout)504 static u32 mlxbf_i2c_poll(void __iomem *io, u32 addr, u32 mask,
505 			    bool eq_zero, u32  timeout)
506 {
507 	u32 bits;
508 
509 	timeout = (timeout / MLXBF_I2C_POLL_FREQ_IN_USEC) + 1;
510 
511 	do {
512 		bits = readl(io + addr) & mask;
513 		if (eq_zero ? bits == 0 : bits != 0)
514 			return eq_zero ? 1 : bits;
515 		udelay(MLXBF_I2C_POLL_FREQ_IN_USEC);
516 	} while (timeout-- != 0);
517 
518 	return 0;
519 }
520 
521 /*
522  * SW must make sure that the SMBus Master GW is idle before starting
523  * a transaction. Accordingly, this function polls the Master FSM stop
524  * bit; it returns false when the bit is asserted, true if not.
525  */
mlxbf_i2c_smbus_master_wait_for_idle(struct mlxbf_i2c_priv * priv)526 static bool mlxbf_i2c_smbus_master_wait_for_idle(struct mlxbf_i2c_priv *priv)
527 {
528 	u32 mask = MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK;
529 	u32 addr = priv->chip->smbus_master_fsm_off;
530 	u32 timeout = MLXBF_I2C_SMBUS_TIMEOUT;
531 
532 	if (mlxbf_i2c_poll(priv->mst->io, addr, mask, true, timeout))
533 		return true;
534 
535 	return false;
536 }
537 
538 /*
539  * wait for the lock to be released before acquiring it.
540  */
mlxbf_i2c_smbus_master_lock(struct mlxbf_i2c_priv * priv)541 static bool mlxbf_i2c_smbus_master_lock(struct mlxbf_i2c_priv *priv)
542 {
543 	if (mlxbf_i2c_poll(priv->mst->io, MLXBF_I2C_SMBUS_MASTER_GW,
544 			   MLXBF_I2C_MASTER_LOCK_BIT, true,
545 			   MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT))
546 		return true;
547 
548 	return false;
549 }
550 
mlxbf_i2c_smbus_master_unlock(struct mlxbf_i2c_priv * priv)551 static void mlxbf_i2c_smbus_master_unlock(struct mlxbf_i2c_priv *priv)
552 {
553 	/* Clear the gw to clear the lock */
554 	writel(0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
555 }
556 
mlxbf_i2c_smbus_transaction_success(u32 master_status,u32 cause_status)557 static bool mlxbf_i2c_smbus_transaction_success(u32 master_status,
558 						u32 cause_status)
559 {
560 	/*
561 	 * When transaction ended with STOP, all bytes were transmitted,
562 	 * and no NACK received, then the transaction ended successfully.
563 	 * On the other hand, when the GW is configured with the stop bit
564 	 * de-asserted then the SMBus expects the following GW configuration
565 	 * for transfer continuation.
566 	 */
567 	if ((cause_status & MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA) ||
568 	    ((cause_status & MLXBF_I2C_CAUSE_TRANSACTION_ENDED) &&
569 	     (master_status & MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE) &&
570 	     !(master_status & MLXBF_I2C_SMBUS_STATUS_NACK_RCV)))
571 		return true;
572 
573 	return false;
574 }
575 
576 /*
577  * Poll SMBus master status and return transaction status,
578  * i.e. whether succeeded or failed. I2C and SMBus fault codes
579  * are returned as negative numbers from most calls, with zero
580  * or some positive number indicating a non-fault return.
581  */
mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv * priv)582 static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv)
583 {
584 	u32 master_status_bits;
585 	u32 cause_status_bits;
586 
587 	/*
588 	 * GW busy bit is raised by the driver and cleared by the HW
589 	 * when the transaction is completed. The busy bit is a good
590 	 * indicator of transaction status. So poll the busy bit, and
591 	 * then read the cause and master status bits to determine if
592 	 * errors occurred during the transaction.
593 	 */
594 	mlxbf_i2c_poll(priv->mst->io, MLXBF_I2C_SMBUS_MASTER_GW,
595 			 MLXBF_I2C_MASTER_BUSY_BIT, true,
596 			 MLXBF_I2C_SMBUS_TIMEOUT);
597 
598 	/* Read cause status bits. */
599 	cause_status_bits = readl(priv->mst_cause->io +
600 					MLXBF_I2C_CAUSE_ARBITER);
601 	cause_status_bits &= MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK;
602 
603 	/*
604 	 * Parse both Cause and Master GW bits, then return transaction status.
605 	 */
606 
607 	master_status_bits = readl(priv->mst->io +
608 					MLXBF_I2C_SMBUS_MASTER_STATUS);
609 	master_status_bits &= MLXBF_I2C_SMBUS_MASTER_STATUS_MASK;
610 
611 	if (mlxbf_i2c_smbus_transaction_success(master_status_bits,
612 						cause_status_bits))
613 		return 0;
614 
615 	/*
616 	 * In case of timeout on GW busy, the ISR will clear busy bit but
617 	 * transaction ended bits cause will not be set so the transaction
618 	 * fails. Then, we must check Master GW status bits.
619 	 */
620 	if ((master_status_bits & MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR) &&
621 	    (cause_status_bits & (MLXBF_I2C_CAUSE_TRANSACTION_ENDED |
622 				  MLXBF_I2C_CAUSE_M_GW_BUSY_FALL)))
623 		return -EIO;
624 
625 	if (cause_status_bits & MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR)
626 		return -EAGAIN;
627 
628 	return -ETIMEDOUT;
629 }
630 
mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv * priv,const u8 * data,u8 length,u32 addr,bool is_master)631 static void mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv *priv,
632 				       const u8 *data, u8 length, u32 addr,
633 				       bool is_master)
634 {
635 	u8 offset, aligned_length;
636 	u32 data32;
637 
638 	aligned_length = round_up(length, 4);
639 
640 	/*
641 	 * Copy data bytes from 4-byte aligned source buffer.
642 	 * Data copied to the Master GW Data Descriptor MUST be shifted
643 	 * left so the data starts at the MSB of the descriptor registers
644 	 * as required by the underlying hardware. Enable byte swapping
645 	 * when writing data bytes to the 32 * 32-bit HW Data registers
646 	 * a.k.a Master GW Data Descriptor.
647 	 */
648 	for (offset = 0; offset < aligned_length; offset += sizeof(u32)) {
649 		data32 = *((u32 *)(data + offset));
650 		if (is_master)
651 			iowrite32be(data32, priv->mst->io + addr + offset);
652 		else
653 			iowrite32be(data32, priv->slv->io + addr + offset);
654 	}
655 }
656 
mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv * priv,u8 * data,u8 length,u32 addr,bool is_master)657 static void mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv *priv,
658 				      u8 *data, u8 length, u32 addr,
659 				      bool is_master)
660 {
661 	u32 data32, mask;
662 	u8 byte, offset;
663 
664 	mask = sizeof(u32) - 1;
665 
666 	/*
667 	 * Data bytes in the Master GW Data Descriptor are shifted left
668 	 * so the data starts at the MSB of the descriptor registers as
669 	 * set by the underlying hardware. Enable byte swapping while
670 	 * reading data bytes from the 32 * 32-bit HW Data registers
671 	 * a.k.a Master GW Data Descriptor.
672 	 */
673 
674 	for (offset = 0; offset < (length & ~mask); offset += sizeof(u32)) {
675 		if (is_master)
676 			data32 = ioread32be(priv->mst->io + addr + offset);
677 		else
678 			data32 = ioread32be(priv->slv->io + addr + offset);
679 		*((u32 *)(data + offset)) = data32;
680 	}
681 
682 	if (!(length & mask))
683 		return;
684 
685 	if (is_master)
686 		data32 = ioread32be(priv->mst->io + addr + offset);
687 	else
688 		data32 = ioread32be(priv->slv->io + addr + offset);
689 
690 	for (byte = 0; byte < (length & mask); byte++) {
691 		data[offset + byte] = data32 & GENMASK(7, 0);
692 		data32 = ror32(data32, MLXBF_I2C_SHIFT_8);
693 	}
694 }
695 
mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv * priv,u8 slave,u8 len,u8 block_en,u8 pec_en,bool read)696 static int mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv *priv, u8 slave,
697 				  u8 len, u8 block_en, u8 pec_en, bool read)
698 {
699 	u32 command;
700 
701 	/* Set Master GW control word. */
702 	if (read) {
703 		command = MLXBF_I2C_MASTER_ENABLE_READ;
704 		command |= rol32(len, MLXBF_I2C_MASTER_READ_SHIFT);
705 	} else {
706 		command = MLXBF_I2C_MASTER_ENABLE_WRITE;
707 		command |= rol32(len, MLXBF_I2C_MASTER_WRITE_SHIFT);
708 	}
709 	command |= rol32(slave, MLXBF_I2C_MASTER_SLV_ADDR_SHIFT);
710 	command |= rol32(block_en, MLXBF_I2C_MASTER_PARSE_EXP_SHIFT);
711 	command |= rol32(pec_en, MLXBF_I2C_MASTER_SEND_PEC_SHIFT);
712 
713 	/* Clear status bits. */
714 	writel(0x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_STATUS);
715 	/* Set the cause data. */
716 	writel(~0x0, priv->mst_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
717 	/* Zero PEC byte. */
718 	writel(0x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_PEC);
719 	/* Zero byte count. */
720 	writel(0x0, priv->mst->io + priv->chip->smbus_master_rs_bytes_off);
721 
722 	/* GW activation. */
723 	writel(command, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
724 
725 	/*
726 	 * Poll master status and check status bits. An ACK is sent when
727 	 * completing writing data to the bus (Master 'byte_count_done' bit
728 	 * is set to 1).
729 	 */
730 	return mlxbf_i2c_smbus_check_status(priv);
731 }
732 
733 static int
mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv * priv,struct mlxbf_i2c_smbus_request * request)734 mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv,
735 				  struct mlxbf_i2c_smbus_request *request)
736 {
737 	u8 data_desc[MLXBF_I2C_MASTER_DATA_DESC_SIZE] = { 0 };
738 	u8 op_idx, data_idx, data_len, write_len, read_len;
739 	struct mlxbf_i2c_smbus_operation *operation;
740 	u8 read_en, write_en, block_en, pec_en;
741 	u8 slave, flags, addr;
742 	u8 *read_buf;
743 	int ret = 0;
744 
745 	if (request->operation_cnt > MLXBF_I2C_SMBUS_MAX_OP_CNT)
746 		return -EINVAL;
747 
748 	read_buf = NULL;
749 	data_idx = 0;
750 	read_en = 0;
751 	write_en = 0;
752 	write_len = 0;
753 	read_len = 0;
754 	block_en = 0;
755 	pec_en = 0;
756 	slave = request->slave & GENMASK(6, 0);
757 	addr = slave << 1;
758 
759 	/*
760 	 * Try to acquire the smbus gw lock before any reads of the GW register since
761 	 * a read sets the lock.
762 	 */
763 	if (WARN_ON(!mlxbf_i2c_smbus_master_lock(priv)))
764 		return -EBUSY;
765 
766 	/* Check whether the HW is idle */
767 	if (WARN_ON(!mlxbf_i2c_smbus_master_wait_for_idle(priv))) {
768 		ret = -EBUSY;
769 		goto out_unlock;
770 	}
771 
772 	/* Set first byte. */
773 	data_desc[data_idx++] = addr;
774 
775 	for (op_idx = 0; op_idx < request->operation_cnt; op_idx++) {
776 		operation = &request->operation[op_idx];
777 		flags = operation->flags;
778 
779 		/*
780 		 * Note that read and write operations might be handled by a
781 		 * single command. If the MLXBF_I2C_F_SMBUS_OPERATION is set
782 		 * then write command byte and set the optional SMBus specific
783 		 * bits such as block_en and pec_en. These bits MUST be
784 		 * submitted by the first operation only.
785 		 */
786 		if (op_idx == 0 && flags & MLXBF_I2C_F_SMBUS_OPERATION) {
787 			block_en = flags & MLXBF_I2C_F_SMBUS_BLOCK;
788 			pec_en = flags & MLXBF_I2C_F_SMBUS_PEC;
789 		}
790 
791 		if (flags & MLXBF_I2C_F_WRITE) {
792 			write_en = 1;
793 			write_len += operation->length;
794 			if (data_idx + operation->length >
795 					MLXBF_I2C_MASTER_DATA_DESC_SIZE) {
796 				ret = -ENOBUFS;
797 				goto out_unlock;
798 			}
799 			memcpy(data_desc + data_idx,
800 			       operation->buffer, operation->length);
801 			data_idx += operation->length;
802 		}
803 		/*
804 		 * We assume that read operations are performed only once per
805 		 * SMBus transaction. *TBD* protect this statement so it won't
806 		 * be executed twice? or return an error if we try to read more
807 		 * than once?
808 		 */
809 		if (flags & MLXBF_I2C_F_READ) {
810 			read_en = 1;
811 			/* Subtract 1 as required by HW. */
812 			read_len = operation->length - 1;
813 			read_buf = operation->buffer;
814 		}
815 	}
816 
817 	/* Set Master GW data descriptor. */
818 	data_len = write_len + 1; /* Add one byte of the slave address. */
819 	/*
820 	 * Note that data_len cannot be 0. Indeed, the slave address byte
821 	 * must be written to the data registers.
822 	 */
823 	mlxbf_i2c_smbus_write_data(priv, (const u8 *)data_desc, data_len,
824 				   MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
825 
826 	if (write_en) {
827 		ret = mlxbf_i2c_smbus_enable(priv, slave, write_len, block_en,
828 					 pec_en, 0);
829 		if (ret)
830 			goto out_unlock;
831 	}
832 
833 	if (read_en) {
834 		/* Write slave address to Master GW data descriptor. */
835 		mlxbf_i2c_smbus_write_data(priv, (const u8 *)&addr, 1,
836 					   MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
837 		ret = mlxbf_i2c_smbus_enable(priv, slave, read_len, block_en,
838 					 pec_en, 1);
839 		if (!ret) {
840 			/* Get Master GW data descriptor. */
841 			mlxbf_i2c_smbus_read_data(priv, data_desc, read_len + 1,
842 					     MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
843 
844 			/* Get data from Master GW data descriptor. */
845 			memcpy(read_buf, data_desc, read_len + 1);
846 		}
847 
848 		/*
849 		 * After a read operation the SMBus FSM ps (present state)
850 		 * needs to be 'manually' reset. This should be removed in
851 		 * next tag integration.
852 		 */
853 		writel(MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK,
854 			priv->mst->io + priv->chip->smbus_master_fsm_off);
855 	}
856 
857 out_unlock:
858 	mlxbf_i2c_smbus_master_unlock(priv);
859 
860 	return ret;
861 }
862 
863 /* I2C SMBus protocols. */
864 
865 static void
mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request * request,u8 read)866 mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request *request,
867 			      u8 read)
868 {
869 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
870 
871 	request->operation[0].length = 0;
872 	request->operation[0].flags = MLXBF_I2C_F_WRITE;
873 	request->operation[0].flags |= read ? MLXBF_I2C_F_READ : 0;
874 }
875 
mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request * request,u8 * data,bool read,bool pec_check)876 static void mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request *request,
877 				      u8 *data, bool read, bool pec_check)
878 {
879 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
880 
881 	request->operation[0].length = 1;
882 	request->operation[0].length += pec_check;
883 
884 	request->operation[0].flags = MLXBF_I2C_F_SMBUS_OPERATION;
885 	request->operation[0].flags |= read ?
886 				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
887 	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
888 
889 	request->operation[0].buffer = data;
890 }
891 
892 static void
mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,bool read,bool pec_check)893 mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request *request,
894 			       u8 *command, u8 *data, bool read, bool pec_check)
895 {
896 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
897 
898 	request->operation[0].length = 1;
899 	request->operation[0].flags =
900 			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
901 	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
902 	request->operation[0].buffer = command;
903 
904 	request->operation[1].length = 1;
905 	request->operation[1].length += pec_check;
906 	request->operation[1].flags = read ?
907 				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
908 	request->operation[1].buffer = data;
909 }
910 
911 static void
mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,bool read,bool pec_check)912 mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request *request,
913 			       u8 *command, u8 *data, bool read, bool pec_check)
914 {
915 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
916 
917 	request->operation[0].length = 1;
918 	request->operation[0].flags =
919 			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
920 	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
921 	request->operation[0].buffer = command;
922 
923 	request->operation[1].length = 2;
924 	request->operation[1].length += pec_check;
925 	request->operation[1].flags = read ?
926 				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
927 	request->operation[1].buffer = data;
928 }
929 
930 static void
mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,u8 * data_len,bool read,bool pec_check)931 mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request *request,
932 			       u8 *command, u8 *data, u8 *data_len, bool read,
933 			       bool pec_check)
934 {
935 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
936 
937 	request->operation[0].length = 1;
938 	request->operation[0].flags =
939 			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
940 	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
941 	request->operation[0].buffer = command;
942 
943 	/*
944 	 * As specified in the standard, the max number of bytes to read/write
945 	 * per block operation is 32 bytes. In Golan code, the controller can
946 	 * read up to 128 bytes and write up to 127 bytes.
947 	 */
948 	request->operation[1].length =
949 	    (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
950 	    I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
951 	request->operation[1].flags = read ?
952 				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
953 	/*
954 	 * Skip the first data byte, which corresponds to the number of bytes
955 	 * to read/write.
956 	 */
957 	request->operation[1].buffer = data + 1;
958 
959 	*data_len = request->operation[1].length;
960 
961 	/* Set the number of byte to read. This will be used by userspace. */
962 	if (read)
963 		data[0] = *data_len;
964 }
965 
mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,u8 * data_len,bool read,bool pec_check)966 static void mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request *request,
967 				       u8 *command, u8 *data, u8 *data_len,
968 				       bool read, bool pec_check)
969 {
970 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
971 
972 	request->operation[0].length = 1;
973 	request->operation[0].flags =
974 			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
975 	request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
976 	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
977 	request->operation[0].buffer = command;
978 
979 	request->operation[1].length =
980 	    (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
981 	    I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
982 	request->operation[1].flags = read ?
983 				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
984 	request->operation[1].buffer = data + 1;
985 
986 	*data_len = request->operation[1].length;
987 
988 	/* Set the number of bytes to read. This will be used by userspace. */
989 	if (read)
990 		data[0] = *data_len;
991 }
992 
993 static void
mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,bool pec_check)994 mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request *request,
995 				  u8 *command, u8 *data, bool pec_check)
996 {
997 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
998 
999 	request->operation[0].length = 1;
1000 	request->operation[0].flags =
1001 			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
1002 	request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
1003 	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
1004 	request->operation[0].buffer = command;
1005 
1006 	request->operation[1].length = 2;
1007 	request->operation[1].flags = MLXBF_I2C_F_WRITE;
1008 	request->operation[1].buffer = data;
1009 
1010 	request->operation[2].length = 3;
1011 	request->operation[2].flags = MLXBF_I2C_F_READ;
1012 	request->operation[2].buffer = data;
1013 }
1014 
1015 static void
mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,u8 * data_len,bool pec_check)1016 mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request *request,
1017 				      u8 *command, u8 *data, u8 *data_len,
1018 				      bool pec_check)
1019 {
1020 	u32 length;
1021 
1022 	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
1023 
1024 	request->operation[0].length = 1;
1025 	request->operation[0].flags =
1026 			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
1027 	request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
1028 	request->operation[0].flags |= (pec_check) ? MLXBF_I2C_F_SMBUS_PEC : 0;
1029 	request->operation[0].buffer = command;
1030 
1031 	length = (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
1032 	    I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
1033 
1034 	request->operation[1].length = length - pec_check;
1035 	request->operation[1].flags = MLXBF_I2C_F_WRITE;
1036 	request->operation[1].buffer = data;
1037 
1038 	request->operation[2].length = length;
1039 	request->operation[2].flags = MLXBF_I2C_F_READ;
1040 	request->operation[2].buffer = data;
1041 
1042 	*data_len = length; /* including PEC byte. */
1043 }
1044 
1045 /* Initialization functions. */
1046 
mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv * priv,u8 type)1047 static bool mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv *priv, u8 type)
1048 {
1049 	return priv->chip->type == type;
1050 }
1051 
1052 static struct mlxbf_i2c_resource *
mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv * priv,u8 type)1053 mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv *priv, u8 type)
1054 {
1055 	const struct mlxbf_i2c_chip_info *chip = priv->chip;
1056 	struct mlxbf_i2c_resource *res;
1057 	u8 res_idx = 0;
1058 
1059 	for (res_idx = 0; res_idx < MLXBF_I2C_SHARED_RES_MAX; res_idx++) {
1060 		res = chip->shared_res[res_idx];
1061 		if (res && res->type == type)
1062 			return res;
1063 	}
1064 
1065 	return NULL;
1066 }
1067 
mlxbf_i2c_init_resource(struct platform_device * pdev,struct mlxbf_i2c_resource ** res,u8 type)1068 static int mlxbf_i2c_init_resource(struct platform_device *pdev,
1069 				   struct mlxbf_i2c_resource **res,
1070 				   u8 type)
1071 {
1072 	struct mlxbf_i2c_resource *tmp_res;
1073 	struct device *dev = &pdev->dev;
1074 
1075 	if (!res || *res || type >= MLXBF_I2C_END_RES)
1076 		return -EINVAL;
1077 
1078 	tmp_res = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource),
1079 			       GFP_KERNEL);
1080 	if (!tmp_res)
1081 		return -ENOMEM;
1082 
1083 	tmp_res->params = platform_get_resource(pdev, IORESOURCE_MEM, type);
1084 	if (!tmp_res->params) {
1085 		devm_kfree(dev, tmp_res);
1086 		return -EIO;
1087 	}
1088 
1089 	tmp_res->io = devm_ioremap_resource(dev, tmp_res->params);
1090 	if (IS_ERR(tmp_res->io)) {
1091 		devm_kfree(dev, tmp_res);
1092 		return PTR_ERR(tmp_res->io);
1093 	}
1094 
1095 	tmp_res->type = type;
1096 
1097 	*res = tmp_res;
1098 
1099 	return 0;
1100 }
1101 
mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv * priv,u64 nanoseconds,bool minimum)1102 static u32 mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv *priv, u64 nanoseconds,
1103 			       bool minimum)
1104 {
1105 	u64 frequency;
1106 	u32 ticks;
1107 
1108 	/*
1109 	 * Compute ticks as follow:
1110 	 *
1111 	 *           Ticks
1112 	 * Time = --------- x 10^9    =>    Ticks = Time x Frequency x 10^-9
1113 	 *         Frequency
1114 	 */
1115 	frequency = priv->frequency;
1116 	ticks = (nanoseconds * frequency) / MLXBF_I2C_FREQUENCY_1GHZ;
1117 	/*
1118 	 * The number of ticks is rounded down and if minimum is equal to 1
1119 	 * then add one tick.
1120 	 */
1121 	if (minimum)
1122 		ticks++;
1123 
1124 	return ticks;
1125 }
1126 
mlxbf_i2c_set_timer(struct mlxbf_i2c_priv * priv,u64 nsec,bool opt,u32 mask,u8 shift)1127 static u32 mlxbf_i2c_set_timer(struct mlxbf_i2c_priv *priv, u64 nsec, bool opt,
1128 			       u32 mask, u8 shift)
1129 {
1130 	u32 val = (mlxbf_i2c_get_ticks(priv, nsec, opt) & mask) << shift;
1131 
1132 	return val;
1133 }
1134 
mlxbf_i2c_set_timings(struct mlxbf_i2c_priv * priv,const struct mlxbf_i2c_timings * timings)1135 static void mlxbf_i2c_set_timings(struct mlxbf_i2c_priv *priv,
1136 				  const struct mlxbf_i2c_timings *timings)
1137 {
1138 	u32 timer;
1139 
1140 	timer = mlxbf_i2c_set_timer(priv, timings->scl_high,
1141 				    false, MLXBF_I2C_MASK_16,
1142 				    MLXBF_I2C_SHIFT_0);
1143 	timer |= mlxbf_i2c_set_timer(priv, timings->scl_low,
1144 				     false, MLXBF_I2C_MASK_16,
1145 				     MLXBF_I2C_SHIFT_16);
1146 	writel(timer, priv->timer->io +
1147 		MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH);
1148 
1149 	timer = mlxbf_i2c_set_timer(priv, timings->sda_rise, false,
1150 				    MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_0);
1151 	timer |= mlxbf_i2c_set_timer(priv, timings->sda_fall, false,
1152 				     MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_8);
1153 	timer |= mlxbf_i2c_set_timer(priv, timings->scl_rise, false,
1154 				     MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_16);
1155 	timer |= mlxbf_i2c_set_timer(priv, timings->scl_fall, false,
1156 				     MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_24);
1157 	writel(timer, priv->timer->io +
1158 		MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE);
1159 
1160 	timer = mlxbf_i2c_set_timer(priv, timings->hold_start, true,
1161 				    MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1162 	timer |= mlxbf_i2c_set_timer(priv, timings->hold_data, true,
1163 				     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1164 	writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_THOLD);
1165 
1166 	timer = mlxbf_i2c_set_timer(priv, timings->setup_start, true,
1167 				    MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1168 	timer |= mlxbf_i2c_set_timer(priv, timings->setup_stop, true,
1169 				     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1170 	writel(timer, priv->timer->io +
1171 		MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP);
1172 
1173 	timer = mlxbf_i2c_set_timer(priv, timings->setup_data, true,
1174 				    MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1175 	writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA);
1176 
1177 	timer = mlxbf_i2c_set_timer(priv, timings->buf, false,
1178 				    MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1179 	timer |= mlxbf_i2c_set_timer(priv, timings->thigh_max, false,
1180 				     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1181 	writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_THIGH_MAX_TBUF);
1182 
1183 	timer = timings->timeout;
1184 	writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT);
1185 }
1186 
1187 enum mlxbf_i2c_timings_config {
1188 	MLXBF_I2C_TIMING_CONFIG_100KHZ,
1189 	MLXBF_I2C_TIMING_CONFIG_400KHZ,
1190 	MLXBF_I2C_TIMING_CONFIG_1000KHZ,
1191 };
1192 
1193 /*
1194  * Note that the mlxbf_i2c_timings->timeout value is not related to the
1195  * bus frequency, it is impacted by the time it takes the driver to
1196  * complete data transmission before transaction abort.
1197  */
1198 static const struct mlxbf_i2c_timings mlxbf_i2c_timings[] = {
1199 	[MLXBF_I2C_TIMING_CONFIG_100KHZ] = {
1200 		.scl_high = 4810,
1201 		.scl_low = 5000,
1202 		.hold_start = 4000,
1203 		.setup_start = 4800,
1204 		.setup_stop = 4000,
1205 		.setup_data = 250,
1206 		.sda_rise = 50,
1207 		.sda_fall = 50,
1208 		.scl_rise = 50,
1209 		.scl_fall = 50,
1210 		.hold_data = 300,
1211 		.buf = 20000,
1212 		.thigh_max = 5000,
1213 		.timeout = 106500
1214 	},
1215 	[MLXBF_I2C_TIMING_CONFIG_400KHZ] = {
1216 		.scl_high = 1011,
1217 		.scl_low = 1300,
1218 		.hold_start = 600,
1219 		.setup_start = 700,
1220 		.setup_stop = 600,
1221 		.setup_data = 100,
1222 		.sda_rise = 50,
1223 		.sda_fall = 50,
1224 		.scl_rise = 50,
1225 		.scl_fall = 50,
1226 		.hold_data = 300,
1227 		.buf = 20000,
1228 		.thigh_max = 5000,
1229 		.timeout = 106500
1230 	},
1231 	[MLXBF_I2C_TIMING_CONFIG_1000KHZ] = {
1232 		.scl_high = 600,
1233 		.scl_low = 1300,
1234 		.hold_start = 600,
1235 		.setup_start = 600,
1236 		.setup_stop = 600,
1237 		.setup_data = 100,
1238 		.sda_rise = 50,
1239 		.sda_fall = 50,
1240 		.scl_rise = 50,
1241 		.scl_fall = 50,
1242 		.hold_data = 300,
1243 		.buf = 20000,
1244 		.thigh_max = 5000,
1245 		.timeout = 106500
1246 	}
1247 };
1248 
mlxbf_i2c_init_timings(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1249 static int mlxbf_i2c_init_timings(struct platform_device *pdev,
1250 				  struct mlxbf_i2c_priv *priv)
1251 {
1252 	enum mlxbf_i2c_timings_config config_idx;
1253 	struct device *dev = &pdev->dev;
1254 	u32 config_khz;
1255 
1256 	int ret;
1257 
1258 	ret = device_property_read_u32(dev, "clock-frequency", &config_khz);
1259 	if (ret < 0)
1260 		config_khz = I2C_MAX_STANDARD_MODE_FREQ;
1261 
1262 	switch (config_khz) {
1263 	default:
1264 		/* Default settings is 100 KHz. */
1265 		pr_warn("Illegal value %d: defaulting to 100 KHz\n",
1266 			config_khz);
1267 		fallthrough;
1268 	case I2C_MAX_STANDARD_MODE_FREQ:
1269 		config_idx = MLXBF_I2C_TIMING_CONFIG_100KHZ;
1270 		break;
1271 
1272 	case I2C_MAX_FAST_MODE_FREQ:
1273 		config_idx = MLXBF_I2C_TIMING_CONFIG_400KHZ;
1274 		break;
1275 
1276 	case I2C_MAX_FAST_MODE_PLUS_FREQ:
1277 		config_idx = MLXBF_I2C_TIMING_CONFIG_1000KHZ;
1278 		break;
1279 	}
1280 
1281 	mlxbf_i2c_set_timings(priv, &mlxbf_i2c_timings[config_idx]);
1282 
1283 	return 0;
1284 }
1285 
mlxbf_i2c_get_gpio(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1286 static int mlxbf_i2c_get_gpio(struct platform_device *pdev,
1287 			      struct mlxbf_i2c_priv *priv)
1288 {
1289 	struct mlxbf_i2c_resource *gpio_res;
1290 	struct device *dev = &pdev->dev;
1291 	struct resource	*params;
1292 	resource_size_t size;
1293 
1294 	gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1295 	if (!gpio_res)
1296 		return -EPERM;
1297 
1298 	/*
1299 	 * The GPIO region in TYU space is shared among I2C busses.
1300 	 * This function MUST be serialized to avoid racing when
1301 	 * claiming the memory region and/or setting up the GPIO.
1302 	 */
1303 	lockdep_assert_held(gpio_res->lock);
1304 
1305 	/* Check whether the memory map exist. */
1306 	if (gpio_res->io)
1307 		return 0;
1308 
1309 	params = gpio_res->params;
1310 	size = resource_size(params);
1311 
1312 	if (!devm_request_mem_region(dev, params->start, size, params->name))
1313 		return -EFAULT;
1314 
1315 	gpio_res->io = devm_ioremap(dev, params->start, size);
1316 	if (!gpio_res->io) {
1317 		devm_release_mem_region(dev, params->start, size);
1318 		return -ENOMEM;
1319 	}
1320 
1321 	return 0;
1322 }
1323 
mlxbf_i2c_release_gpio(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1324 static int mlxbf_i2c_release_gpio(struct platform_device *pdev,
1325 				  struct mlxbf_i2c_priv *priv)
1326 {
1327 	struct mlxbf_i2c_resource *gpio_res;
1328 	struct device *dev = &pdev->dev;
1329 	struct resource	*params;
1330 
1331 	gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1332 	if (!gpio_res)
1333 		return 0;
1334 
1335 	mutex_lock(gpio_res->lock);
1336 
1337 	if (gpio_res->io) {
1338 		/* Release the GPIO resource. */
1339 		params = gpio_res->params;
1340 		devm_iounmap(dev, gpio_res->io);
1341 		devm_release_mem_region(dev, params->start,
1342 					resource_size(params));
1343 	}
1344 
1345 	mutex_unlock(gpio_res->lock);
1346 
1347 	return 0;
1348 }
1349 
mlxbf_i2c_get_corepll(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1350 static int mlxbf_i2c_get_corepll(struct platform_device *pdev,
1351 				 struct mlxbf_i2c_priv *priv)
1352 {
1353 	struct mlxbf_i2c_resource *corepll_res;
1354 	struct device *dev = &pdev->dev;
1355 	struct resource *params;
1356 	resource_size_t size;
1357 
1358 	corepll_res = mlxbf_i2c_get_shared_resource(priv,
1359 						    MLXBF_I2C_COREPLL_RES);
1360 	if (!corepll_res)
1361 		return -EPERM;
1362 
1363 	/*
1364 	 * The COREPLL region in TYU space is shared among I2C busses.
1365 	 * This function MUST be serialized to avoid racing when
1366 	 * claiming the memory region.
1367 	 */
1368 	lockdep_assert_held(corepll_res->lock);
1369 
1370 	/* Check whether the memory map exist. */
1371 	if (corepll_res->io)
1372 		return 0;
1373 
1374 	params = corepll_res->params;
1375 	size = resource_size(params);
1376 
1377 	if (!devm_request_mem_region(dev, params->start, size, params->name))
1378 		return -EFAULT;
1379 
1380 	corepll_res->io = devm_ioremap(dev, params->start, size);
1381 	if (!corepll_res->io) {
1382 		devm_release_mem_region(dev, params->start, size);
1383 		return -ENOMEM;
1384 	}
1385 
1386 	return 0;
1387 }
1388 
mlxbf_i2c_release_corepll(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1389 static int mlxbf_i2c_release_corepll(struct platform_device *pdev,
1390 				     struct mlxbf_i2c_priv *priv)
1391 {
1392 	struct mlxbf_i2c_resource *corepll_res;
1393 	struct device *dev = &pdev->dev;
1394 	struct resource *params;
1395 
1396 	corepll_res = mlxbf_i2c_get_shared_resource(priv,
1397 						    MLXBF_I2C_COREPLL_RES);
1398 
1399 	mutex_lock(corepll_res->lock);
1400 
1401 	if (corepll_res->io) {
1402 		/* Release the CorePLL resource. */
1403 		params = corepll_res->params;
1404 		devm_iounmap(dev, corepll_res->io);
1405 		devm_release_mem_region(dev, params->start,
1406 					resource_size(params));
1407 	}
1408 
1409 	mutex_unlock(corepll_res->lock);
1410 
1411 	return 0;
1412 }
1413 
mlxbf_i2c_init_master(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1414 static int mlxbf_i2c_init_master(struct platform_device *pdev,
1415 				 struct mlxbf_i2c_priv *priv)
1416 {
1417 	struct mlxbf_i2c_resource *gpio_res;
1418 	struct device *dev = &pdev->dev;
1419 	u32 config_reg;
1420 	int ret;
1421 
1422 	/* This configuration is only needed for BlueField 1. */
1423 	if (!mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1))
1424 		return 0;
1425 
1426 	gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1427 	if (!gpio_res)
1428 		return -EPERM;
1429 
1430 	/*
1431 	 * The GPIO region in TYU space is shared among I2C busses.
1432 	 * This function MUST be serialized to avoid racing when
1433 	 * claiming the memory region and/or setting up the GPIO.
1434 	 */
1435 
1436 	mutex_lock(gpio_res->lock);
1437 
1438 	ret = mlxbf_i2c_get_gpio(pdev, priv);
1439 	if (ret < 0) {
1440 		dev_err(dev, "Failed to get gpio resource");
1441 		mutex_unlock(gpio_res->lock);
1442 		return ret;
1443 	}
1444 
1445 	/*
1446 	 * TYU - Configuration for GPIO pins. Those pins must be asserted in
1447 	 * MLXBF_I2C_GPIO_0_FUNC_EN_0, i.e. GPIO 0 is controlled by HW, and must
1448 	 * be reset in MLXBF_I2C_GPIO_0_FORCE_OE_EN, i.e. GPIO_OE will be driven
1449 	 * instead of HW_OE.
1450 	 * For now, we do not reset the GPIO state when the driver is removed.
1451 	 * First, it is not necessary to disable the bus since we are using
1452 	 * the same busses. Then, some busses might be shared among Linux and
1453 	 * platform firmware; disabling the bus might compromise the system
1454 	 * functionality.
1455 	 */
1456 	config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
1457 	config_reg = MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(priv->bus,
1458 							 config_reg);
1459 	writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
1460 
1461 	config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
1462 	config_reg = MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(priv->bus,
1463 							config_reg);
1464 	writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
1465 
1466 	mutex_unlock(gpio_res->lock);
1467 
1468 	return 0;
1469 }
1470 
mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource * corepll_res)1471 static u64 mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_res)
1472 {
1473 	u64 core_frequency;
1474 	u8 core_od, core_r;
1475 	u32 corepll_val;
1476 	u16 core_f;
1477 
1478 	corepll_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
1479 
1480 	/* Get Core PLL configuration bits. */
1481 	core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_TYU_MASK, corepll_val);
1482 	core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK, corepll_val);
1483 	core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_TYU_MASK, corepll_val);
1484 
1485 	/*
1486 	 * Compute PLL output frequency as follow:
1487 	 *
1488 	 *                                       CORE_F + 1
1489 	 * PLL_OUT_FREQ = PLL_IN_FREQ * ----------------------------
1490 	 *                              (CORE_R + 1) * (CORE_OD + 1)
1491 	 *
1492 	 * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
1493 	 * and PadFrequency, respectively.
1494 	 */
1495 	core_frequency = MLXBF_I2C_PLL_IN_FREQ * (++core_f);
1496 	core_frequency /= (++core_r) * (++core_od);
1497 
1498 	return core_frequency;
1499 }
1500 
mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource * corepll_res)1501 static u64 mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res)
1502 {
1503 	u32 corepll_reg1_val, corepll_reg2_val;
1504 	u64 corepll_frequency;
1505 	u8 core_od, core_r;
1506 	u32 core_f;
1507 
1508 	corepll_reg1_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
1509 	corepll_reg2_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG2);
1510 
1511 	/* Get Core PLL configuration bits */
1512 	core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_YU_MASK, corepll_reg1_val);
1513 	core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_YU_MASK, corepll_reg1_val);
1514 	core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_YU_MASK, corepll_reg2_val);
1515 
1516 	/*
1517 	 * Compute PLL output frequency as follow:
1518 	 *
1519 	 *                                     CORE_F / 16384
1520 	 * PLL_OUT_FREQ = PLL_IN_FREQ * ----------------------------
1521 	 *                              (CORE_R + 1) * (CORE_OD + 1)
1522 	 *
1523 	 * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
1524 	 * and PadFrequency, respectively.
1525 	 */
1526 	corepll_frequency = (MLXBF_I2C_PLL_IN_FREQ * core_f) / MLNXBF_I2C_COREPLL_CONST;
1527 	corepll_frequency /= (++core_r) * (++core_od);
1528 
1529 	return corepll_frequency;
1530 }
1531 
mlxbf_i2c_calculate_corepll_freq(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1532 static int mlxbf_i2c_calculate_corepll_freq(struct platform_device *pdev,
1533 					    struct mlxbf_i2c_priv *priv)
1534 {
1535 	const struct mlxbf_i2c_chip_info *chip = priv->chip;
1536 	struct mlxbf_i2c_resource *corepll_res;
1537 	struct device *dev = &pdev->dev;
1538 	u64 *freq = &priv->frequency;
1539 	int ret;
1540 
1541 	corepll_res = mlxbf_i2c_get_shared_resource(priv,
1542 						    MLXBF_I2C_COREPLL_RES);
1543 	if (!corepll_res)
1544 		return -EPERM;
1545 
1546 	/*
1547 	 * First, check whether the TYU core Clock frequency is set.
1548 	 * The TYU core frequency is the same for all I2C busses; when
1549 	 * the first device gets probed the frequency is determined and
1550 	 * stored into a globally visible variable. So, first of all,
1551 	 * check whether the frequency is already set. Here, we assume
1552 	 * that the frequency is expected to be greater than 0.
1553 	 */
1554 	mutex_lock(corepll_res->lock);
1555 	if (!mlxbf_i2c_corepll_frequency) {
1556 		if (!chip->calculate_freq) {
1557 			mutex_unlock(corepll_res->lock);
1558 			return -EPERM;
1559 		}
1560 
1561 		ret = mlxbf_i2c_get_corepll(pdev, priv);
1562 		if (ret < 0) {
1563 			dev_err(dev, "Failed to get corePLL resource");
1564 			mutex_unlock(corepll_res->lock);
1565 			return ret;
1566 		}
1567 
1568 		mlxbf_i2c_corepll_frequency = chip->calculate_freq(corepll_res);
1569 	}
1570 	mutex_unlock(corepll_res->lock);
1571 
1572 	*freq = mlxbf_i2c_corepll_frequency;
1573 
1574 	return 0;
1575 }
1576 
mlxbf_i2c_slave_enable(struct mlxbf_i2c_priv * priv,struct i2c_client * slave)1577 static int mlxbf_i2c_slave_enable(struct mlxbf_i2c_priv *priv,
1578 			      struct i2c_client *slave)
1579 {
1580 	u8 reg, reg_cnt, byte, addr_tmp;
1581 	u32 slave_reg, slave_reg_tmp;
1582 
1583 	if (!priv)
1584 		return -EPERM;
1585 
1586 	reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
1587 
1588 	/*
1589 	 * Read the slave registers. There are 4 * 32-bit slave registers.
1590 	 * Each slave register can hold up to 4 * 8-bit slave configuration:
1591 	 * 1) A 7-bit address
1592 	 * 2) And a status bit (1 if enabled, 0 if not).
1593 	 * Look for the next available slave register slot.
1594 	 */
1595 	for (reg = 0; reg < reg_cnt; reg++) {
1596 		slave_reg = readl(priv->slv->io +
1597 				MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
1598 		/*
1599 		 * Each register holds 4 slave addresses. So, we have to keep
1600 		 * the byte order consistent with the value read in order to
1601 		 * update the register correctly, if needed.
1602 		 */
1603 		slave_reg_tmp = slave_reg;
1604 		for (byte = 0; byte < 4; byte++) {
1605 			addr_tmp = slave_reg_tmp & GENMASK(7, 0);
1606 
1607 			/*
1608 			 * If an enable bit is not set in the
1609 			 * MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG register, then the
1610 			 * slave address slot associated with that bit is
1611 			 * free. So set the enable bit and write the
1612 			 * slave address bits.
1613 			 */
1614 			if (!(addr_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT)) {
1615 				slave_reg &= ~(MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK << (byte * 8));
1616 				slave_reg |= (slave->addr << (byte * 8));
1617 				slave_reg |= MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT << (byte * 8);
1618 				writel(slave_reg, priv->slv->io +
1619 					MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
1620 					(reg * 0x4));
1621 
1622 				/*
1623 				 * Set the slave at the corresponding index.
1624 				 */
1625 				priv->slave[(reg * 4) + byte] = slave;
1626 
1627 				return 0;
1628 			}
1629 
1630 			/* Parse next byte. */
1631 			slave_reg_tmp >>= 8;
1632 		}
1633 	}
1634 
1635 	return -EBUSY;
1636 }
1637 
mlxbf_i2c_slave_disable(struct mlxbf_i2c_priv * priv,u8 addr)1638 static int mlxbf_i2c_slave_disable(struct mlxbf_i2c_priv *priv, u8 addr)
1639 {
1640 	u8 addr_tmp, reg, reg_cnt, byte;
1641 	u32 slave_reg, slave_reg_tmp;
1642 
1643 	reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
1644 
1645 	/*
1646 	 * Read the slave registers. There are 4 * 32-bit slave registers.
1647 	 * Each slave register can hold up to 4 * 8-bit slave configuration:
1648 	 * 1) A 7-bit address
1649 	 * 2) And a status bit (1 if enabled, 0 if not).
1650 	 * Check if addr is present in the registers.
1651 	 */
1652 	for (reg = 0; reg < reg_cnt; reg++) {
1653 		slave_reg = readl(priv->slv->io +
1654 				MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
1655 
1656 		/* Check whether the address slots are empty. */
1657 		if (!slave_reg)
1658 			continue;
1659 
1660 		/*
1661 		 * Check if addr matches any of the 4 slave addresses
1662 		 * in the register.
1663 		 */
1664 		slave_reg_tmp = slave_reg;
1665 		for (byte = 0; byte < 4; byte++) {
1666 			addr_tmp = slave_reg_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK;
1667 			/*
1668 			 * Parse slave address bytes and check whether the
1669 			 * slave address already exists.
1670 			 */
1671 			if (addr_tmp == addr) {
1672 				/* Clear the slave address slot. */
1673 				slave_reg &= ~(GENMASK(7, 0) << (byte * 8));
1674 				writel(slave_reg, priv->slv->io +
1675 					MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
1676 					(reg * 0x4));
1677 				/* Free slave at the corresponding index */
1678 				priv->slave[(reg * 4) + byte] = NULL;
1679 
1680 				return 0;
1681 			}
1682 
1683 			/* Parse next byte. */
1684 			slave_reg_tmp >>= 8;
1685 		}
1686 	}
1687 
1688 	return -ENXIO;
1689 }
1690 
mlxbf_i2c_init_coalesce(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1691 static int mlxbf_i2c_init_coalesce(struct platform_device *pdev,
1692 				   struct mlxbf_i2c_priv *priv)
1693 {
1694 	struct mlxbf_i2c_resource *coalesce_res;
1695 	struct resource *params;
1696 	resource_size_t size;
1697 	int ret = 0;
1698 
1699 	/*
1700 	 * Unlike BlueField-1 platform, the coalesce registers is a dedicated
1701 	 * resource in the next generations of BlueField.
1702 	 */
1703 	if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
1704 		coalesce_res = mlxbf_i2c_get_shared_resource(priv,
1705 						MLXBF_I2C_COALESCE_RES);
1706 		if (!coalesce_res)
1707 			return -EPERM;
1708 
1709 		/*
1710 		 * The Cause Coalesce group in TYU space is shared among
1711 		 * I2C busses. This function MUST be serialized to avoid
1712 		 * racing when claiming the memory region.
1713 		 */
1714 		lockdep_assert_held(mlxbf_i2c_gpio_res->lock);
1715 
1716 		/* Check whether the memory map exist. */
1717 		if (coalesce_res->io) {
1718 			priv->coalesce = coalesce_res;
1719 			return 0;
1720 		}
1721 
1722 		params = coalesce_res->params;
1723 		size = resource_size(params);
1724 
1725 		if (!request_mem_region(params->start, size, params->name))
1726 			return -EFAULT;
1727 
1728 		coalesce_res->io = ioremap(params->start, size);
1729 		if (!coalesce_res->io) {
1730 			release_mem_region(params->start, size);
1731 			return -ENOMEM;
1732 		}
1733 
1734 		priv->coalesce = coalesce_res;
1735 
1736 	} else {
1737 		ret = mlxbf_i2c_init_resource(pdev, &priv->coalesce,
1738 					      MLXBF_I2C_COALESCE_RES);
1739 	}
1740 
1741 	return ret;
1742 }
1743 
mlxbf_i2c_release_coalesce(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1744 static int mlxbf_i2c_release_coalesce(struct platform_device *pdev,
1745 				      struct mlxbf_i2c_priv *priv)
1746 {
1747 	struct mlxbf_i2c_resource *coalesce_res;
1748 	struct device *dev = &pdev->dev;
1749 	struct resource *params;
1750 	resource_size_t size;
1751 
1752 	coalesce_res = priv->coalesce;
1753 
1754 	if (coalesce_res->io) {
1755 		params = coalesce_res->params;
1756 		size = resource_size(params);
1757 		if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
1758 			mutex_lock(coalesce_res->lock);
1759 			iounmap(coalesce_res->io);
1760 			release_mem_region(params->start, size);
1761 			mutex_unlock(coalesce_res->lock);
1762 		} else {
1763 			devm_release_mem_region(dev, params->start, size);
1764 		}
1765 	}
1766 
1767 	return 0;
1768 }
1769 
mlxbf_i2c_init_slave(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1770 static int mlxbf_i2c_init_slave(struct platform_device *pdev,
1771 				struct mlxbf_i2c_priv *priv)
1772 {
1773 	struct device *dev = &pdev->dev;
1774 	u32 int_reg;
1775 	int ret;
1776 
1777 	/* Reset FSM. */
1778 	writel(0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_FSM);
1779 
1780 	/*
1781 	 * Enable slave cause interrupt bits. Drive
1782 	 * MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE and
1783 	 * MLXBF_I2C_CAUSE_WRITE_SUCCESS, these are enabled when an external
1784 	 * masters issue a Read and Write, respectively. But, clear all
1785 	 * interrupts first.
1786 	 */
1787 	writel(~0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
1788 	int_reg = MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE;
1789 	int_reg |= MLXBF_I2C_CAUSE_WRITE_SUCCESS;
1790 	writel(int_reg, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_EVTEN0);
1791 
1792 	/* Finally, set the 'ready' bit to start handling transactions. */
1793 	writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1794 
1795 	/* Initialize the cause coalesce resource. */
1796 	ret = mlxbf_i2c_init_coalesce(pdev, priv);
1797 	if (ret < 0) {
1798 		dev_err(dev, "failed to initialize cause coalesce\n");
1799 		return ret;
1800 	}
1801 
1802 	return 0;
1803 }
1804 
mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv * priv,bool * read,bool * write)1805 static bool mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv *priv, bool *read,
1806 				   bool *write)
1807 {
1808 	const struct mlxbf_i2c_chip_info *chip = priv->chip;
1809 	u32 coalesce0_reg, cause_reg;
1810 	u8 slave_shift, is_set;
1811 
1812 	*write = false;
1813 	*read = false;
1814 
1815 	slave_shift = chip->type != MLXBF_I2C_CHIP_TYPE_1 ?
1816 				MLXBF_I2C_CAUSE_YU_SLAVE_BIT :
1817 				priv->bus + MLXBF_I2C_CAUSE_TYU_SLAVE_BIT;
1818 
1819 	coalesce0_reg = readl(priv->coalesce->io + MLXBF_I2C_CAUSE_COALESCE_0);
1820 	is_set = coalesce0_reg & (1 << slave_shift);
1821 
1822 	if (!is_set)
1823 		return false;
1824 
1825 	/* Check the source of the interrupt, i.e. whether a Read or Write. */
1826 	cause_reg = readl(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER);
1827 	if (cause_reg & MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE)
1828 		*read = true;
1829 	else if (cause_reg & MLXBF_I2C_CAUSE_WRITE_SUCCESS)
1830 		*write = true;
1831 
1832 	/* Clear cause bits. */
1833 	writel(~0x0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
1834 
1835 	return true;
1836 }
1837 
mlxbf_i2c_slave_wait_for_idle(struct mlxbf_i2c_priv * priv,u32 timeout)1838 static bool mlxbf_i2c_slave_wait_for_idle(struct mlxbf_i2c_priv *priv,
1839 					    u32 timeout)
1840 {
1841 	u32 mask = MLXBF_I2C_CAUSE_S_GW_BUSY_FALL;
1842 	u32 addr = MLXBF_I2C_CAUSE_ARBITER;
1843 
1844 	if (mlxbf_i2c_poll(priv->slv_cause->io, addr, mask, false, timeout))
1845 		return true;
1846 
1847 	return false;
1848 }
1849 
mlxbf_i2c_get_slave_from_addr(struct mlxbf_i2c_priv * priv,u8 addr)1850 static struct i2c_client *mlxbf_i2c_get_slave_from_addr(
1851 			struct mlxbf_i2c_priv *priv, u8 addr)
1852 {
1853 	int i;
1854 
1855 	for (i = 0; i < MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT; i++) {
1856 		if (!priv->slave[i])
1857 			continue;
1858 
1859 		if (priv->slave[i]->addr == addr)
1860 			return priv->slave[i];
1861 	}
1862 
1863 	return NULL;
1864 }
1865 
1866 /*
1867  * Send byte to 'external' smbus master. This function is executed when
1868  * an external smbus master wants to read data from the BlueField.
1869  */
mlxbf_i2c_irq_send(struct mlxbf_i2c_priv * priv,u8 recv_bytes)1870 static int mlxbf_i2c_irq_send(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
1871 {
1872 	u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
1873 	u8 write_size, pec_en, addr, value, byte_cnt;
1874 	struct i2c_client *slave;
1875 	u32 control32, data32;
1876 	int ret = 0;
1877 
1878 	/*
1879 	 * Read the first byte received from the external master to
1880 	 * determine the slave address. This byte is located in the
1881 	 * first data descriptor register of the slave GW.
1882 	 */
1883 	data32 = ioread32be(priv->slv->io +
1884 				MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
1885 	addr = (data32 & GENMASK(7, 0)) >> 1;
1886 
1887 	/*
1888 	 * Check if the slave address received in the data descriptor register
1889 	 * matches any of the slave addresses registered. If there is a match,
1890 	 * set the slave.
1891 	 */
1892 	slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
1893 	if (!slave) {
1894 		ret = -ENXIO;
1895 		goto clear_csr;
1896 	}
1897 
1898 	/*
1899 	 * An I2C read can consist of a WRITE bit transaction followed by
1900 	 * a READ bit transaction. Indeed, slave devices often expect
1901 	 * the slave address to be followed by the internal address.
1902 	 * So, write the internal address byte first, and then, send the
1903 	 * requested data to the master.
1904 	 */
1905 	if (recv_bytes > 1) {
1906 		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1907 		value = (data32 >> 8) & GENMASK(7, 0);
1908 		ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
1909 				      &value);
1910 		i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1911 
1912 		if (ret < 0)
1913 			goto clear_csr;
1914 	}
1915 
1916 	/*
1917 	 * Send data to the master. Currently, the driver supports
1918 	 * READ_BYTE, READ_WORD and BLOCK READ protocols. The
1919 	 * hardware can send up to 128 bytes per transfer which is
1920 	 * the total size of the data registers.
1921 	 */
1922 	i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1923 
1924 	for (byte_cnt = 0; byte_cnt < MLXBF_I2C_SLAVE_DATA_DESC_SIZE; byte_cnt++) {
1925 		data_desc[byte_cnt] = value;
1926 		i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value);
1927 	}
1928 
1929 	/* Send a stop condition to the backend. */
1930 	i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1931 
1932 	/* Set the number of bytes to write to master. */
1933 	write_size = (byte_cnt - 1) & 0x7f;
1934 
1935 	/* Write data to Slave GW data descriptor. */
1936 	mlxbf_i2c_smbus_write_data(priv, data_desc, byte_cnt,
1937 				   MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false);
1938 
1939 	pec_en = 0; /* Disable PEC since it is not supported. */
1940 
1941 	/* Prepare control word. */
1942 	control32 = MLXBF_I2C_SLAVE_ENABLE;
1943 	control32 |= rol32(write_size, MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT);
1944 	control32 |= rol32(pec_en, MLXBF_I2C_SLAVE_SEND_PEC_SHIFT);
1945 
1946 	writel(control32, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_GW);
1947 
1948 	/*
1949 	 * Wait until the transfer is completed; the driver will wait
1950 	 * until the GW is idle, a cause will rise on fall of GW busy.
1951 	 */
1952 	mlxbf_i2c_slave_wait_for_idle(priv, MLXBF_I2C_SMBUS_TIMEOUT);
1953 
1954 clear_csr:
1955 	/* Release the Slave GW. */
1956 	writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
1957 	writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
1958 	writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1959 
1960 	return ret;
1961 }
1962 
1963 /*
1964  * Receive bytes from 'external' smbus master. This function is executed when
1965  * an external smbus master wants to write data to the BlueField.
1966  */
mlxbf_i2c_irq_recv(struct mlxbf_i2c_priv * priv,u8 recv_bytes)1967 static int mlxbf_i2c_irq_recv(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
1968 {
1969 	u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
1970 	struct i2c_client *slave;
1971 	u8 value, byte, addr;
1972 	int ret = 0;
1973 
1974 	/* Read data from Slave GW data descriptor. */
1975 	mlxbf_i2c_smbus_read_data(priv, data_desc, recv_bytes,
1976 				  MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false);
1977 	addr = data_desc[0] >> 1;
1978 
1979 	/*
1980 	 * Check if the slave address received in the data descriptor register
1981 	 * matches any of the slave addresses registered.
1982 	 */
1983 	slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
1984 	if (!slave) {
1985 		ret = -EINVAL;
1986 		goto clear_csr;
1987 	}
1988 
1989 	/*
1990 	 * Notify the slave backend that an smbus master wants to write data
1991 	 * to the BlueField.
1992 	 */
1993 	i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1994 
1995 	/* Send the received data to the slave backend. */
1996 	for (byte = 1; byte < recv_bytes; byte++) {
1997 		value = data_desc[byte];
1998 		ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
1999 				      &value);
2000 		if (ret < 0)
2001 			break;
2002 	}
2003 
2004 	/*
2005 	 * Send a stop event to the slave backend, to signal
2006 	 * the end of the write transactions.
2007 	 */
2008 	i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
2009 
2010 clear_csr:
2011 	/* Release the Slave GW. */
2012 	writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
2013 	writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
2014 	writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
2015 
2016 	return ret;
2017 }
2018 
mlxbf_i2c_irq(int irq,void * ptr)2019 static irqreturn_t mlxbf_i2c_irq(int irq, void *ptr)
2020 {
2021 	struct mlxbf_i2c_priv *priv = ptr;
2022 	bool read, write, irq_is_set;
2023 	u32 rw_bytes_reg;
2024 	u8 recv_bytes;
2025 
2026 	/*
2027 	 * Read TYU interrupt register and determine the source of the
2028 	 * interrupt. Based on the source of the interrupt one of the
2029 	 * following actions are performed:
2030 	 *  - Receive data and send response to master.
2031 	 *  - Send data and release slave GW.
2032 	 *
2033 	 * Handle read/write transaction only. CRmaster and Iarp requests
2034 	 * are ignored for now.
2035 	 */
2036 	irq_is_set = mlxbf_i2c_has_coalesce(priv, &read, &write);
2037 	if (!irq_is_set || (!read && !write)) {
2038 		/* Nothing to do here, interrupt was not from this device. */
2039 		return IRQ_NONE;
2040 	}
2041 
2042 	/*
2043 	 * The MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES includes the number of
2044 	 * bytes from/to master. These are defined by 8-bits each. If the lower
2045 	 * 8 bits are set, then the master expect to read N bytes from the
2046 	 * slave, if the higher 8 bits are sent then the slave expect N bytes
2047 	 * from the master.
2048 	 */
2049 	rw_bytes_reg = readl(priv->slv->io +
2050 				MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
2051 	recv_bytes = (rw_bytes_reg >> 8) & GENMASK(7, 0);
2052 
2053 	/*
2054 	 * For now, the slave supports 128 bytes transfer. Discard remaining
2055 	 * data bytes if the master wrote more than
2056 	 * MLXBF_I2C_SLAVE_DATA_DESC_SIZE, i.e, the actual size of the slave
2057 	 * data descriptor.
2058 	 *
2059 	 * Note that we will never expect to transfer more than 128 bytes; as
2060 	 * specified in the SMBus standard, block transactions cannot exceed
2061 	 * 32 bytes.
2062 	 */
2063 	recv_bytes = recv_bytes > MLXBF_I2C_SLAVE_DATA_DESC_SIZE ?
2064 		MLXBF_I2C_SLAVE_DATA_DESC_SIZE : recv_bytes;
2065 
2066 	if (read)
2067 		mlxbf_i2c_irq_send(priv, recv_bytes);
2068 	else
2069 		mlxbf_i2c_irq_recv(priv, recv_bytes);
2070 
2071 	return IRQ_HANDLED;
2072 }
2073 
2074 /* Return negative errno on error. */
mlxbf_i2c_smbus_xfer(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)2075 static s32 mlxbf_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
2076 				unsigned short flags, char read_write,
2077 				u8 command, int size,
2078 				union i2c_smbus_data *data)
2079 {
2080 	struct mlxbf_i2c_smbus_request request = { 0 };
2081 	struct mlxbf_i2c_priv *priv;
2082 	bool read, pec;
2083 	u8 byte_cnt;
2084 
2085 	request.slave = addr;
2086 
2087 	read = (read_write == I2C_SMBUS_READ);
2088 	pec = flags & I2C_FUNC_SMBUS_PEC;
2089 
2090 	switch (size) {
2091 	case I2C_SMBUS_QUICK:
2092 		mlxbf_i2c_smbus_quick_command(&request, read);
2093 		dev_dbg(&adap->dev, "smbus quick, slave 0x%02x\n", addr);
2094 		break;
2095 
2096 	case I2C_SMBUS_BYTE:
2097 		mlxbf_i2c_smbus_byte_func(&request,
2098 					  read ? &data->byte : &command, read,
2099 					  pec);
2100 		dev_dbg(&adap->dev, "smbus %s byte, slave 0x%02x.\n",
2101 			read ? "read" : "write", addr);
2102 		break;
2103 
2104 	case I2C_SMBUS_BYTE_DATA:
2105 		mlxbf_i2c_smbus_data_byte_func(&request, &command, &data->byte,
2106 					       read, pec);
2107 		dev_dbg(&adap->dev, "smbus %s byte data at 0x%02x, slave 0x%02x.\n",
2108 			read ? "read" : "write", command, addr);
2109 		break;
2110 
2111 	case I2C_SMBUS_WORD_DATA:
2112 		mlxbf_i2c_smbus_data_word_func(&request, &command,
2113 					       (u8 *)&data->word, read, pec);
2114 		dev_dbg(&adap->dev, "smbus %s word data at 0x%02x, slave 0x%02x.\n",
2115 			read ? "read" : "write", command, addr);
2116 		break;
2117 
2118 	case I2C_SMBUS_I2C_BLOCK_DATA:
2119 		byte_cnt = data->block[0];
2120 		mlxbf_i2c_smbus_i2c_block_func(&request, &command, data->block,
2121 					       &byte_cnt, read, pec);
2122 		dev_dbg(&adap->dev, "i2c %s block data, %d bytes at 0x%02x, slave 0x%02x.\n",
2123 			read ? "read" : "write", byte_cnt, command, addr);
2124 		break;
2125 
2126 	case I2C_SMBUS_BLOCK_DATA:
2127 		byte_cnt = read ? I2C_SMBUS_BLOCK_MAX : data->block[0];
2128 		mlxbf_i2c_smbus_block_func(&request, &command, data->block,
2129 					   &byte_cnt, read, pec);
2130 		dev_dbg(&adap->dev, "smbus %s block data, %d bytes at 0x%02x, slave 0x%02x.\n",
2131 			read ? "read" : "write", byte_cnt, command, addr);
2132 		break;
2133 
2134 	case I2C_FUNC_SMBUS_PROC_CALL:
2135 		mlxbf_i2c_smbus_process_call_func(&request, &command,
2136 						  (u8 *)&data->word, pec);
2137 		dev_dbg(&adap->dev, "process call, wr/rd at 0x%02x, slave 0x%02x.\n",
2138 			command, addr);
2139 		break;
2140 
2141 	case I2C_FUNC_SMBUS_BLOCK_PROC_CALL:
2142 		byte_cnt = data->block[0];
2143 		mlxbf_i2c_smbus_blk_process_call_func(&request, &command,
2144 						      data->block, &byte_cnt,
2145 						      pec);
2146 		dev_dbg(&adap->dev, "block process call, wr/rd %d bytes, slave 0x%02x.\n",
2147 			byte_cnt, addr);
2148 		break;
2149 
2150 	default:
2151 		dev_dbg(&adap->dev, "Unsupported I2C/SMBus command %d\n",
2152 			size);
2153 		return -EOPNOTSUPP;
2154 	}
2155 
2156 	priv = i2c_get_adapdata(adap);
2157 
2158 	return mlxbf_i2c_smbus_start_transaction(priv, &request);
2159 }
2160 
mlxbf_i2c_reg_slave(struct i2c_client * slave)2161 static int mlxbf_i2c_reg_slave(struct i2c_client *slave)
2162 {
2163 	struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
2164 	struct device *dev = &slave->dev;
2165 	int ret;
2166 
2167 	/*
2168 	 * Do not support ten bit chip address and do not use Packet Error
2169 	 * Checking (PEC).
2170 	 */
2171 	if (slave->flags & (I2C_CLIENT_TEN | I2C_CLIENT_PEC)) {
2172 		dev_err(dev, "SMBus PEC and 10 bit address not supported\n");
2173 		return -EAFNOSUPPORT;
2174 	}
2175 
2176 	ret = mlxbf_i2c_slave_enable(priv, slave);
2177 	if (ret)
2178 		dev_err(dev, "Surpassed max number of registered slaves allowed\n");
2179 
2180 	return 0;
2181 }
2182 
mlxbf_i2c_unreg_slave(struct i2c_client * slave)2183 static int mlxbf_i2c_unreg_slave(struct i2c_client *slave)
2184 {
2185 	struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
2186 	struct device *dev = &slave->dev;
2187 	int ret;
2188 
2189 	/*
2190 	 * Unregister slave by:
2191 	 * 1) Disabling the slave address in hardware
2192 	 * 2) Freeing priv->slave at the corresponding index
2193 	 */
2194 	ret = mlxbf_i2c_slave_disable(priv, slave->addr);
2195 	if (ret)
2196 		dev_err(dev, "Unable to find slave 0x%x\n", slave->addr);
2197 
2198 	return ret;
2199 }
2200 
mlxbf_i2c_functionality(struct i2c_adapter * adap)2201 static u32 mlxbf_i2c_functionality(struct i2c_adapter *adap)
2202 {
2203 	return MLXBF_I2C_FUNC_ALL;
2204 }
2205 
2206 static struct mlxbf_i2c_chip_info mlxbf_i2c_chip[] = {
2207 	[MLXBF_I2C_CHIP_TYPE_1] = {
2208 		.type = MLXBF_I2C_CHIP_TYPE_1,
2209 		.shared_res = {
2210 			[0] = &mlxbf_i2c_coalesce_res[MLXBF_I2C_CHIP_TYPE_1],
2211 			[1] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_1],
2212 			[2] = &mlxbf_i2c_gpio_res[MLXBF_I2C_CHIP_TYPE_1]
2213 		},
2214 		.calculate_freq = mlxbf_i2c_calculate_freq_from_tyu,
2215 		.smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
2216 		.smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
2217 	},
2218 	[MLXBF_I2C_CHIP_TYPE_2] = {
2219 		.type = MLXBF_I2C_CHIP_TYPE_2,
2220 		.shared_res = {
2221 			[0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_2]
2222 		},
2223 		.calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
2224 		.smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
2225 		.smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
2226 	},
2227 	[MLXBF_I2C_CHIP_TYPE_3] = {
2228 		.type = MLXBF_I2C_CHIP_TYPE_3,
2229 		.shared_res = {
2230 			[0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_3]
2231 		},
2232 		.calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
2233 		.smbus_master_rs_bytes_off = MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES,
2234 		.smbus_master_fsm_off = MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM
2235 	}
2236 };
2237 
2238 static const struct i2c_algorithm mlxbf_i2c_algo = {
2239 	.smbus_xfer = mlxbf_i2c_smbus_xfer,
2240 	.functionality = mlxbf_i2c_functionality,
2241 	.reg_slave = mlxbf_i2c_reg_slave,
2242 	.unreg_slave = mlxbf_i2c_unreg_slave,
2243 };
2244 
2245 static struct i2c_adapter_quirks mlxbf_i2c_quirks = {
2246 	.max_read_len = MLXBF_I2C_MASTER_DATA_R_LENGTH,
2247 	.max_write_len = MLXBF_I2C_MASTER_DATA_W_LENGTH,
2248 };
2249 
2250 static const struct acpi_device_id mlxbf_i2c_acpi_ids[] = {
2251 	{ "MLNXBF03", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1] },
2252 	{ "MLNXBF23", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2] },
2253 	{ "MLNXBF31", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_3] },
2254 	{},
2255 };
2256 
2257 MODULE_DEVICE_TABLE(acpi, mlxbf_i2c_acpi_ids);
2258 
mlxbf_i2c_acpi_probe(struct device * dev,struct mlxbf_i2c_priv * priv)2259 static int mlxbf_i2c_acpi_probe(struct device *dev, struct mlxbf_i2c_priv *priv)
2260 {
2261 	const struct acpi_device_id *aid;
2262 	u64 bus_id;
2263 	int ret;
2264 
2265 	if (acpi_disabled)
2266 		return -ENOENT;
2267 
2268 	aid = acpi_match_device(mlxbf_i2c_acpi_ids, dev);
2269 	if (!aid)
2270 		return -ENODEV;
2271 
2272 	priv->chip = (struct mlxbf_i2c_chip_info *)aid->driver_data;
2273 
2274 	ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &bus_id);
2275 	if (ret) {
2276 		dev_err(dev, "Cannot retrieve UID\n");
2277 		return ret;
2278 	}
2279 
2280 	priv->bus = bus_id;
2281 
2282 	return 0;
2283 }
2284 
mlxbf_i2c_probe(struct platform_device * pdev)2285 static int mlxbf_i2c_probe(struct platform_device *pdev)
2286 {
2287 	struct device *dev = &pdev->dev;
2288 	struct mlxbf_i2c_priv *priv;
2289 	struct i2c_adapter *adap;
2290 	u32 resource_version;
2291 	int irq, ret;
2292 
2293 	priv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_priv), GFP_KERNEL);
2294 	if (!priv)
2295 		return -ENOMEM;
2296 
2297 	ret = mlxbf_i2c_acpi_probe(dev, priv);
2298 	if (ret < 0)
2299 		return ret;
2300 
2301 	/* This property allows the driver to stay backward compatible with older
2302 	 * ACPI tables.
2303 	 * Starting BlueField-3 SoC, the "smbus" resource was broken down into 3
2304 	 * separate resources "timer", "master" and "slave".
2305 	 */
2306 	if (device_property_read_u32(dev, "resource_version", &resource_version))
2307 		resource_version = 0;
2308 
2309 	priv->resource_version = resource_version;
2310 
2311 	if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && resource_version == 0) {
2312 		priv->timer = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2313 		if (!priv->timer)
2314 			return -ENOMEM;
2315 
2316 		priv->mst = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2317 		if (!priv->mst)
2318 			return -ENOMEM;
2319 
2320 		priv->slv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2321 		if (!priv->slv)
2322 			return -ENOMEM;
2323 
2324 		ret = mlxbf_i2c_init_resource(pdev, &priv->smbus,
2325 					      MLXBF_I2C_SMBUS_RES);
2326 		if (ret < 0) {
2327 			dev_err(dev, "Cannot fetch smbus resource info");
2328 			return ret;
2329 		}
2330 
2331 		priv->timer->io = priv->smbus->io;
2332 		priv->mst->io = priv->smbus->io + MLXBF_I2C_MST_ADDR_OFFSET;
2333 		priv->slv->io = priv->smbus->io + MLXBF_I2C_SLV_ADDR_OFFSET;
2334 	} else {
2335 		ret = mlxbf_i2c_init_resource(pdev, &priv->timer,
2336 					      MLXBF_I2C_SMBUS_TIMER_RES);
2337 		if (ret < 0) {
2338 			dev_err(dev, "Cannot fetch timer resource info");
2339 			return ret;
2340 		}
2341 
2342 		ret = mlxbf_i2c_init_resource(pdev, &priv->mst,
2343 					      MLXBF_I2C_SMBUS_MST_RES);
2344 		if (ret < 0) {
2345 			dev_err(dev, "Cannot fetch master resource info");
2346 			return ret;
2347 		}
2348 
2349 		ret = mlxbf_i2c_init_resource(pdev, &priv->slv,
2350 					      MLXBF_I2C_SMBUS_SLV_RES);
2351 		if (ret < 0) {
2352 			dev_err(dev, "Cannot fetch slave resource info");
2353 			return ret;
2354 		}
2355 	}
2356 
2357 	ret = mlxbf_i2c_init_resource(pdev, &priv->mst_cause,
2358 				      MLXBF_I2C_MST_CAUSE_RES);
2359 	if (ret < 0) {
2360 		dev_err(dev, "Cannot fetch cause master resource info");
2361 		return ret;
2362 	}
2363 
2364 	ret = mlxbf_i2c_init_resource(pdev, &priv->slv_cause,
2365 				      MLXBF_I2C_SLV_CAUSE_RES);
2366 	if (ret < 0) {
2367 		dev_err(dev, "Cannot fetch cause slave resource info");
2368 		return ret;
2369 	}
2370 
2371 	adap = &priv->adap;
2372 	adap->owner = THIS_MODULE;
2373 	adap->class = I2C_CLASS_HWMON;
2374 	adap->algo = &mlxbf_i2c_algo;
2375 	adap->quirks = &mlxbf_i2c_quirks;
2376 	adap->dev.parent = dev;
2377 	adap->dev.of_node = dev->of_node;
2378 	adap->nr = priv->bus;
2379 
2380 	snprintf(adap->name, sizeof(adap->name), "i2c%d", adap->nr);
2381 	i2c_set_adapdata(adap, priv);
2382 
2383 	/* Read Core PLL frequency. */
2384 	ret = mlxbf_i2c_calculate_corepll_freq(pdev, priv);
2385 	if (ret < 0) {
2386 		dev_err(dev, "cannot get core clock frequency\n");
2387 		/* Set to default value. */
2388 		priv->frequency = MLXBF_I2C_COREPLL_FREQ;
2389 	}
2390 
2391 	/*
2392 	 * Initialize master.
2393 	 * Note that a physical bus might be shared among Linux and firmware
2394 	 * (e.g., ATF). Thus, the bus should be initialized and ready and
2395 	 * bus initialization would be unnecessary. This requires additional
2396 	 * knowledge about physical busses. But, since an extra initialization
2397 	 * does not really hurt, then keep the code as is.
2398 	 */
2399 	ret = mlxbf_i2c_init_master(pdev, priv);
2400 	if (ret < 0) {
2401 		dev_err(dev, "failed to initialize smbus master %d",
2402 			priv->bus);
2403 		return ret;
2404 	}
2405 
2406 	mlxbf_i2c_init_timings(pdev, priv);
2407 
2408 	mlxbf_i2c_init_slave(pdev, priv);
2409 
2410 	irq = platform_get_irq(pdev, 0);
2411 	if (irq < 0)
2412 		return irq;
2413 	ret = devm_request_irq(dev, irq, mlxbf_i2c_irq,
2414 			       IRQF_SHARED | IRQF_PROBE_SHARED,
2415 			       dev_name(dev), priv);
2416 	if (ret < 0) {
2417 		dev_err(dev, "Cannot get irq %d\n", irq);
2418 		return ret;
2419 	}
2420 
2421 	priv->irq = irq;
2422 
2423 	platform_set_drvdata(pdev, priv);
2424 
2425 	ret = i2c_add_numbered_adapter(adap);
2426 	if (ret < 0)
2427 		return ret;
2428 
2429 	mutex_lock(&mlxbf_i2c_bus_lock);
2430 	mlxbf_i2c_bus_count++;
2431 	mutex_unlock(&mlxbf_i2c_bus_lock);
2432 
2433 	return 0;
2434 }
2435 
mlxbf_i2c_remove(struct platform_device * pdev)2436 static int mlxbf_i2c_remove(struct platform_device *pdev)
2437 {
2438 	struct mlxbf_i2c_priv *priv = platform_get_drvdata(pdev);
2439 	struct device *dev = &pdev->dev;
2440 	struct resource *params;
2441 
2442 	if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && priv->resource_version == 0) {
2443 		params = priv->smbus->params;
2444 		devm_release_mem_region(dev, params->start, resource_size(params));
2445 	} else {
2446 		params = priv->timer->params;
2447 		devm_release_mem_region(dev, params->start, resource_size(params));
2448 
2449 		params = priv->mst->params;
2450 		devm_release_mem_region(dev, params->start, resource_size(params));
2451 
2452 		params = priv->slv->params;
2453 		devm_release_mem_region(dev, params->start, resource_size(params));
2454 	}
2455 
2456 	params = priv->mst_cause->params;
2457 	devm_release_mem_region(dev, params->start, resource_size(params));
2458 
2459 	params = priv->slv_cause->params;
2460 	devm_release_mem_region(dev, params->start, resource_size(params));
2461 
2462 	/*
2463 	 * Release shared resources. This should be done when releasing
2464 	 * the I2C controller.
2465 	 */
2466 	mutex_lock(&mlxbf_i2c_bus_lock);
2467 	if (--mlxbf_i2c_bus_count == 0) {
2468 		mlxbf_i2c_release_coalesce(pdev, priv);
2469 		mlxbf_i2c_release_corepll(pdev, priv);
2470 		mlxbf_i2c_release_gpio(pdev, priv);
2471 	}
2472 	mutex_unlock(&mlxbf_i2c_bus_lock);
2473 
2474 	devm_free_irq(dev, priv->irq, priv);
2475 
2476 	i2c_del_adapter(&priv->adap);
2477 
2478 	return 0;
2479 }
2480 
2481 static struct platform_driver mlxbf_i2c_driver = {
2482 	.probe = mlxbf_i2c_probe,
2483 	.remove = mlxbf_i2c_remove,
2484 	.driver = {
2485 		.name = "i2c-mlxbf",
2486 		.acpi_match_table = ACPI_PTR(mlxbf_i2c_acpi_ids),
2487 	},
2488 };
2489 
mlxbf_i2c_init(void)2490 static int __init mlxbf_i2c_init(void)
2491 {
2492 	mutex_init(&mlxbf_i2c_coalesce_lock);
2493 	mutex_init(&mlxbf_i2c_corepll_lock);
2494 	mutex_init(&mlxbf_i2c_gpio_lock);
2495 
2496 	mutex_init(&mlxbf_i2c_bus_lock);
2497 
2498 	return platform_driver_register(&mlxbf_i2c_driver);
2499 }
2500 module_init(mlxbf_i2c_init);
2501 
mlxbf_i2c_exit(void)2502 static void __exit mlxbf_i2c_exit(void)
2503 {
2504 	platform_driver_unregister(&mlxbf_i2c_driver);
2505 
2506 	mutex_destroy(&mlxbf_i2c_bus_lock);
2507 
2508 	mutex_destroy(&mlxbf_i2c_gpio_lock);
2509 	mutex_destroy(&mlxbf_i2c_corepll_lock);
2510 	mutex_destroy(&mlxbf_i2c_coalesce_lock);
2511 }
2512 module_exit(mlxbf_i2c_exit);
2513 
2514 MODULE_DESCRIPTION("Mellanox BlueField I2C bus driver");
2515 MODULE_AUTHOR("Khalil Blaiech <kblaiech@nvidia.com>");
2516 MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
2517 MODULE_LICENSE("GPL v2");
2518