1 /*
2  * intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
3  *
4  * (C) Copyright 2008-2010 Intel Corporation
5  * Author: Sreedhara DS (sreedhara.ds@intel.com)
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; version 2
10  * of the License.
11  *
12  * SCU running in ARC processor communicates with other entity running in IA
13  * core through IPC mechanism which in turn messaging between IA core ad SCU.
14  * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and
15  * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with
16  * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC)
17  * along with other APIs.
18  */
19 #include <linux/delay.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/sysdev.h>
23 #include <linux/pm.h>
24 #include <linux/pci.h>
25 #include <linux/interrupt.h>
26 #include <linux/sfi.h>
27 #include <asm/mrst.h>
28 #include <asm/intel_scu_ipc.h>
29 
30 /* IPC defines the following message types */
31 #define IPCMSG_WATCHDOG_TIMER 0xF8 /* Set Kernel Watchdog Threshold */
32 #define IPCMSG_BATTERY        0xEF /* Coulomb Counter Accumulator */
33 #define IPCMSG_FW_UPDATE      0xFE /* Firmware update */
34 #define IPCMSG_PCNTRL         0xFF /* Power controller unit read/write */
35 #define IPCMSG_FW_REVISION    0xF4 /* Get firmware revision */
36 
37 /* Command id associated with message IPCMSG_PCNTRL */
38 #define IPC_CMD_PCNTRL_W      0 /* Register write */
39 #define IPC_CMD_PCNTRL_R      1 /* Register read */
40 #define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
41 
42 /*
43  * IPC register summary
44  *
45  * IPC register blocks are memory mapped at fixed address of 0xFF11C000
46  * To read or write information to the SCU, driver writes to IPC-1 memory
47  * mapped registers (base address 0xFF11C000). The following is the IPC
48  * mechanism
49  *
50  * 1. IA core cDMI interface claims this transaction and converts it to a
51  *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
52  *
53  * 2. South Complex cDMI block receives this message and writes it to
54  *    the IPC-1 register block, causing an interrupt to the SCU
55  *
56  * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
57  *    message handler is called within firmware.
58  */
59 
60 #define IPC_BASE_ADDR     0xFF11C000	/* IPC1 base register address */
61 #define IPC_MAX_ADDR      0x100		/* Maximum IPC regisers */
62 #define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
63 #define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
64 #define IPC_I2C_BASE      0xFF12B000	/* I2C control register base address */
65 #define IPC_I2C_MAX_ADDR  0x10		/* Maximum I2C regisers */
66 
67 static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id);
68 static void ipc_remove(struct pci_dev *pdev);
69 
70 struct intel_scu_ipc_dev {
71 	struct pci_dev *pdev;
72 	void __iomem *ipc_base;
73 	void __iomem *i2c_base;
74 };
75 
76 static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
77 
78 static int platform;		/* Platform type */
79 
80 /*
81  * IPC Read Buffer (Read Only):
82  * 16 byte buffer for receiving data from SCU, if IPC command
83  * processing results in response data
84  */
85 #define IPC_READ_BUFFER		0x90
86 
87 #define IPC_I2C_CNTRL_ADDR	0
88 #define I2C_DATA_ADDR		0x04
89 
90 static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
91 
92 /*
93  * Command Register (Write Only):
94  * A write to this register results in an interrupt to the SCU core processor
95  * Format:
96  * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
97  */
ipc_command(u32 cmd)98 static inline void ipc_command(u32 cmd) /* Send ipc command */
99 {
100 	writel(cmd, ipcdev.ipc_base);
101 }
102 
103 /*
104  * IPC Write Buffer (Write Only):
105  * 16-byte buffer for sending data associated with IPC command to
106  * SCU. Size of the data is specified in the IPC_COMMAND_REG register
107  */
ipc_data_writel(u32 data,u32 offset)108 static inline void ipc_data_writel(u32 data, u32 offset) /* Write ipc data */
109 {
110 	writel(data, ipcdev.ipc_base + 0x80 + offset);
111 }
112 
113 /*
114  * Status Register (Read Only):
115  * Driver will read this register to get the ready/busy status of the IPC
116  * block and error status of the IPC command that was just processed by SCU
117  * Format:
118  * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
119  */
120 
ipc_read_status(void)121 static inline u8 ipc_read_status(void)
122 {
123 	return __raw_readl(ipcdev.ipc_base + 0x04);
124 }
125 
ipc_data_readb(u32 offset)126 static inline u8 ipc_data_readb(u32 offset) /* Read ipc byte data */
127 {
128 	return readb(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
129 }
130 
ipc_data_readl(u32 offset)131 static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
132 {
133 	return readl(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
134 }
135 
busy_loop(void)136 static inline int busy_loop(void) /* Wait till scu status is busy */
137 {
138 	u32 status = 0;
139 	u32 loop_count = 0;
140 
141 	status = ipc_read_status();
142 	while (status & 1) {
143 		udelay(1); /* scu processing time is in few u secods */
144 		status = ipc_read_status();
145 		loop_count++;
146 		/* break if scu doesn't reset busy bit after huge retry */
147 		if (loop_count > 100000) {
148 			dev_err(&ipcdev.pdev->dev, "IPC timed out");
149 			return -ETIMEDOUT;
150 		}
151 	}
152 	if ((status >> 1) & 1)
153 		return -EIO;
154 
155 	return 0;
156 }
157 
158 /* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
pwr_reg_rdwr(u16 * addr,u8 * data,u32 count,u32 op,u32 id)159 static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
160 {
161 	int i, nc, bytes, d;
162 	u32 offset = 0;
163 	int err;
164 	u8 cbuf[IPC_WWBUF_SIZE] = { };
165 	u32 *wbuf = (u32 *)&cbuf;
166 
167 	mutex_lock(&ipclock);
168 
169 	memset(cbuf, 0, sizeof(cbuf));
170 
171 	if (ipcdev.pdev == NULL) {
172 		mutex_unlock(&ipclock);
173 		return -ENODEV;
174 	}
175 
176 	if (platform != MRST_CPU_CHIP_PENWELL) {
177 		bytes = 0;
178 		d = 0;
179 		for (i = 0; i < count; i++) {
180 			cbuf[bytes++] = addr[i];
181 			cbuf[bytes++] = addr[i] >> 8;
182 			if (id != IPC_CMD_PCNTRL_R)
183 				cbuf[bytes++] = data[d++];
184 			if (id == IPC_CMD_PCNTRL_M)
185 				cbuf[bytes++] = data[d++];
186 		}
187 		for (i = 0; i < bytes; i += 4)
188 			ipc_data_writel(wbuf[i/4], i);
189 		ipc_command(bytes << 16 |  id << 12 | 0 << 8 | op);
190 	} else {
191 		for (nc = 0; nc < count; nc++, offset += 2) {
192 			cbuf[offset] = addr[nc];
193 			cbuf[offset + 1] = addr[nc] >> 8;
194 		}
195 
196 		if (id == IPC_CMD_PCNTRL_R) {
197 			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
198 				ipc_data_writel(wbuf[nc], offset);
199 			ipc_command((count*2) << 16 |  id << 12 | 0 << 8 | op);
200 		} else if (id == IPC_CMD_PCNTRL_W) {
201 			for (nc = 0; nc < count; nc++, offset += 1)
202 				cbuf[offset] = data[nc];
203 			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
204 				ipc_data_writel(wbuf[nc], offset);
205 			ipc_command((count*3) << 16 |  id << 12 | 0 << 8 | op);
206 		} else if (id == IPC_CMD_PCNTRL_M) {
207 			cbuf[offset] = data[0];
208 			cbuf[offset + 1] = data[1];
209 			ipc_data_writel(wbuf[0], 0); /* Write wbuff */
210 			ipc_command(4 << 16 |  id << 12 | 0 << 8 | op);
211 		}
212 	}
213 
214 	err = busy_loop();
215 	if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
216 		/* Workaround: values are read as 0 without memcpy_fromio */
217 		memcpy_fromio(cbuf, ipcdev.ipc_base + 0x90, 16);
218 		if (platform != MRST_CPU_CHIP_PENWELL) {
219 			for (nc = 0, offset = 2; nc < count; nc++, offset += 3)
220 				data[nc] = ipc_data_readb(offset);
221 		} else {
222 			for (nc = 0; nc < count; nc++)
223 				data[nc] = ipc_data_readb(nc);
224 		}
225 	}
226 	mutex_unlock(&ipclock);
227 	return err;
228 }
229 
230 /**
231  *	intel_scu_ipc_ioread8		-	read a word via the SCU
232  *	@addr: register on SCU
233  *	@data: return pointer for read byte
234  *
235  *	Read a single register. Returns 0 on success or an error code. All
236  *	locking between SCU accesses is handled for the caller.
237  *
238  *	This function may sleep.
239  */
intel_scu_ipc_ioread8(u16 addr,u8 * data)240 int intel_scu_ipc_ioread8(u16 addr, u8 *data)
241 {
242 	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
243 }
244 EXPORT_SYMBOL(intel_scu_ipc_ioread8);
245 
246 /**
247  *	intel_scu_ipc_ioread16		-	read a word via the SCU
248  *	@addr: register on SCU
249  *	@data: return pointer for read word
250  *
251  *	Read a register pair. Returns 0 on success or an error code. All
252  *	locking between SCU accesses is handled for the caller.
253  *
254  *	This function may sleep.
255  */
intel_scu_ipc_ioread16(u16 addr,u16 * data)256 int intel_scu_ipc_ioread16(u16 addr, u16 *data)
257 {
258 	u16 x[2] = {addr, addr + 1 };
259 	return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
260 }
261 EXPORT_SYMBOL(intel_scu_ipc_ioread16);
262 
263 /**
264  *	intel_scu_ipc_ioread32		-	read a dword via the SCU
265  *	@addr: register on SCU
266  *	@data: return pointer for read dword
267  *
268  *	Read four registers. Returns 0 on success or an error code. All
269  *	locking between SCU accesses is handled for the caller.
270  *
271  *	This function may sleep.
272  */
intel_scu_ipc_ioread32(u16 addr,u32 * data)273 int intel_scu_ipc_ioread32(u16 addr, u32 *data)
274 {
275 	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
276 	return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
277 }
278 EXPORT_SYMBOL(intel_scu_ipc_ioread32);
279 
280 /**
281  *	intel_scu_ipc_iowrite8		-	write a byte via the SCU
282  *	@addr: register on SCU
283  *	@data: byte to write
284  *
285  *	Write a single register. Returns 0 on success or an error code. All
286  *	locking between SCU accesses is handled for the caller.
287  *
288  *	This function may sleep.
289  */
intel_scu_ipc_iowrite8(u16 addr,u8 data)290 int intel_scu_ipc_iowrite8(u16 addr, u8 data)
291 {
292 	return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
293 }
294 EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
295 
296 /**
297  *	intel_scu_ipc_iowrite16		-	write a word via the SCU
298  *	@addr: register on SCU
299  *	@data: word to write
300  *
301  *	Write two registers. Returns 0 on success or an error code. All
302  *	locking between SCU accesses is handled for the caller.
303  *
304  *	This function may sleep.
305  */
intel_scu_ipc_iowrite16(u16 addr,u16 data)306 int intel_scu_ipc_iowrite16(u16 addr, u16 data)
307 {
308 	u16 x[2] = {addr, addr + 1 };
309 	return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
310 }
311 EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
312 
313 /**
314  *	intel_scu_ipc_iowrite32		-	write a dword via the SCU
315  *	@addr: register on SCU
316  *	@data: dword to write
317  *
318  *	Write four registers. Returns 0 on success or an error code. All
319  *	locking between SCU accesses is handled for the caller.
320  *
321  *	This function may sleep.
322  */
intel_scu_ipc_iowrite32(u16 addr,u32 data)323 int intel_scu_ipc_iowrite32(u16 addr, u32 data)
324 {
325 	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
326 	return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
327 }
328 EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
329 
330 /**
331  *	intel_scu_ipc_readvv		-	read a set of registers
332  *	@addr: register list
333  *	@data: bytes to return
334  *	@len: length of array
335  *
336  *	Read registers. Returns 0 on success or an error code. All
337  *	locking between SCU accesses is handled for the caller.
338  *
339  *	The largest array length permitted by the hardware is 5 items.
340  *
341  *	This function may sleep.
342  */
intel_scu_ipc_readv(u16 * addr,u8 * data,int len)343 int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
344 {
345 	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
346 }
347 EXPORT_SYMBOL(intel_scu_ipc_readv);
348 
349 /**
350  *	intel_scu_ipc_writev		-	write a set of registers
351  *	@addr: register list
352  *	@data: bytes to write
353  *	@len: length of array
354  *
355  *	Write registers. Returns 0 on success or an error code. All
356  *	locking between SCU accesses is handled for the caller.
357  *
358  *	The largest array length permitted by the hardware is 5 items.
359  *
360  *	This function may sleep.
361  *
362  */
intel_scu_ipc_writev(u16 * addr,u8 * data,int len)363 int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
364 {
365 	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
366 }
367 EXPORT_SYMBOL(intel_scu_ipc_writev);
368 
369 
370 /**
371  *	intel_scu_ipc_update_register	-	r/m/w a register
372  *	@addr: register address
373  *	@bits: bits to update
374  *	@mask: mask of bits to update
375  *
376  *	Read-modify-write power control unit register. The first data argument
377  *	must be register value and second is mask value
378  *	mask is a bitmap that indicates which bits to update.
379  *	0 = masked. Don't modify this bit, 1 = modify this bit.
380  *	returns 0 on success or an error code.
381  *
382  *	This function may sleep. Locking between SCU accesses is handled
383  *	for the caller.
384  */
intel_scu_ipc_update_register(u16 addr,u8 bits,u8 mask)385 int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
386 {
387 	u8 data[2] = { bits, mask };
388 	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
389 }
390 EXPORT_SYMBOL(intel_scu_ipc_update_register);
391 
392 /**
393  *	intel_scu_ipc_simple_command	-	send a simple command
394  *	@cmd: command
395  *	@sub: sub type
396  *
397  *	Issue a simple command to the SCU. Do not use this interface if
398  *	you must then access data as any data values may be overwritten
399  *	by another SCU access by the time this function returns.
400  *
401  *	This function may sleep. Locking for SCU accesses is handled for
402  *	the caller.
403  */
intel_scu_ipc_simple_command(int cmd,int sub)404 int intel_scu_ipc_simple_command(int cmd, int sub)
405 {
406 	int err;
407 
408 	mutex_lock(&ipclock);
409 	if (ipcdev.pdev == NULL) {
410 		mutex_unlock(&ipclock);
411 		return -ENODEV;
412 	}
413 	ipc_command(sub << 12 | cmd);
414 	err = busy_loop();
415 	mutex_unlock(&ipclock);
416 	return err;
417 }
418 EXPORT_SYMBOL(intel_scu_ipc_simple_command);
419 
420 /**
421  *	intel_scu_ipc_command	-	command with data
422  *	@cmd: command
423  *	@sub: sub type
424  *	@in: input data
425  *	@inlen: input length in dwords
426  *	@out: output data
427  *	@outlein: output length in dwords
428  *
429  *	Issue a command to the SCU which involves data transfers. Do the
430  *	data copies under the lock but leave it for the caller to interpret
431  */
432 
intel_scu_ipc_command(int cmd,int sub,u32 * in,int inlen,u32 * out,int outlen)433 int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
434 							u32 *out, int outlen)
435 {
436 	int i, err;
437 
438 	mutex_lock(&ipclock);
439 	if (ipcdev.pdev == NULL) {
440 		mutex_unlock(&ipclock);
441 		return -ENODEV;
442 	}
443 
444 	for (i = 0; i < inlen; i++)
445 		ipc_data_writel(*in++, 4 * i);
446 
447 	ipc_command((inlen << 16) | (sub << 12) | cmd);
448 	err = busy_loop();
449 
450 	for (i = 0; i < outlen; i++)
451 		*out++ = ipc_data_readl(4 * i);
452 
453 	mutex_unlock(&ipclock);
454 	return err;
455 }
456 EXPORT_SYMBOL(intel_scu_ipc_command);
457 
458 /*I2C commands */
459 #define IPC_I2C_WRITE 1 /* I2C Write command */
460 #define IPC_I2C_READ  2 /* I2C Read command */
461 
462 /**
463  *	intel_scu_ipc_i2c_cntrl		-	I2C read/write operations
464  *	@addr: I2C address + command bits
465  *	@data: data to read/write
466  *
467  *	Perform an an I2C read/write operation via the SCU. All locking is
468  *	handled for the caller. This function may sleep.
469  *
470  *	Returns an error code or 0 on success.
471  *
472  *	This has to be in the IPC driver for the locking.
473  */
intel_scu_ipc_i2c_cntrl(u32 addr,u32 * data)474 int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
475 {
476 	u32 cmd = 0;
477 
478 	mutex_lock(&ipclock);
479 	if (ipcdev.pdev == NULL) {
480 		mutex_unlock(&ipclock);
481 		return -ENODEV;
482 	}
483 	cmd = (addr >> 24) & 0xFF;
484 	if (cmd == IPC_I2C_READ) {
485 		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
486 		/* Write not getting updated without delay */
487 		mdelay(1);
488 		*data = readl(ipcdev.i2c_base + I2C_DATA_ADDR);
489 	} else if (cmd == IPC_I2C_WRITE) {
490 		writel(*data, ipcdev.i2c_base + I2C_DATA_ADDR);
491 		mdelay(1);
492 		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
493 	} else {
494 		dev_err(&ipcdev.pdev->dev,
495 			"intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
496 
497 		mutex_unlock(&ipclock);
498 		return -EIO;
499 	}
500 	mutex_unlock(&ipclock);
501 	return 0;
502 }
503 EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
504 
505 #define IPC_FW_LOAD_ADDR 0xFFFC0000 /* Storage location for FW image */
506 #define IPC_FW_UPDATE_MBOX_ADDR 0xFFFFDFF4 /* Mailbox between ipc and scu */
507 #define IPC_MAX_FW_SIZE 262144 /* 256K storage size for loading the FW image */
508 #define IPC_FW_MIP_HEADER_SIZE 2048 /* Firmware MIP header size */
509 /* IPC inform SCU to get ready for update process */
510 #define IPC_CMD_FW_UPDATE_READY  0x10FE
511 /* IPC inform SCU to go for update process */
512 #define IPC_CMD_FW_UPDATE_GO     0x20FE
513 /* Status code for fw update */
514 #define IPC_FW_UPDATE_SUCCESS	0x444f4e45 /* Status code 'DONE' */
515 #define IPC_FW_UPDATE_BADN	0x4241444E /* Status code 'BADN' */
516 #define IPC_FW_TXHIGH		0x54784849 /* Status code 'IPC_FW_TXHIGH' */
517 #define IPC_FW_TXLOW		0x54784c4f /* Status code 'IPC_FW_TXLOW' */
518 
519 struct fw_update_mailbox {
520 	u32    status;
521 	u32    scu_flag;
522 	u32    driver_flag;
523 };
524 
525 
526 /**
527  *	intel_scu_ipc_fw_update	-	 Firmware update utility
528  *	@buffer: firmware buffer
529  *	@length: size of firmware buffer
530  *
531  *	This function provides an interface to load the firmware into
532  *	the SCU. Returns 0 on success or -1 on failure
533  */
intel_scu_ipc_fw_update(u8 * buffer,u32 length)534 int intel_scu_ipc_fw_update(u8 *buffer, u32 length)
535 {
536 	void __iomem *fw_update_base;
537 	struct fw_update_mailbox __iomem *mailbox = NULL;
538 	int retry_cnt = 0;
539 	u32 status;
540 
541 	mutex_lock(&ipclock);
542 	fw_update_base = ioremap_nocache(IPC_FW_LOAD_ADDR, (128*1024));
543 	if (fw_update_base == NULL) {
544 		mutex_unlock(&ipclock);
545 		return -ENOMEM;
546 	}
547 	mailbox = ioremap_nocache(IPC_FW_UPDATE_MBOX_ADDR,
548 					sizeof(struct fw_update_mailbox));
549 	if (mailbox == NULL) {
550 		iounmap(fw_update_base);
551 		mutex_unlock(&ipclock);
552 		return -ENOMEM;
553 	}
554 
555 	ipc_command(IPC_CMD_FW_UPDATE_READY);
556 
557 	/* Intitialize mailbox */
558 	writel(0, &mailbox->status);
559 	writel(0, &mailbox->scu_flag);
560 	writel(0, &mailbox->driver_flag);
561 
562 	/* Driver copies the 2KB MIP header to SRAM at 0xFFFC0000*/
563 	memcpy_toio(fw_update_base, buffer, 0x800);
564 
565 	/* Driver sends "FW Update" IPC command (CMD_ID 0xFE; MSG_ID 0x02).
566 	* Upon receiving this command, SCU will write the 2K MIP header
567 	* from 0xFFFC0000 into NAND.
568 	* SCU will write a status code into the Mailbox, and then set scu_flag.
569 	*/
570 
571 	ipc_command(IPC_CMD_FW_UPDATE_GO);
572 
573 	/*Driver stalls until scu_flag is set */
574 	while (readl(&mailbox->scu_flag) != 1) {
575 		rmb();
576 		mdelay(1);
577 	}
578 
579 	/* Driver checks Mailbox status.
580 	 * If the status is 'BADN', then abort (bad NAND).
581 	 * If the status is 'IPC_FW_TXLOW', then continue.
582 	 */
583 	while (readl(&mailbox->status) != IPC_FW_TXLOW) {
584 		rmb();
585 		mdelay(10);
586 	}
587 	mdelay(10);
588 
589 update_retry:
590 	if (retry_cnt > 5)
591 		goto update_end;
592 
593 	if (readl(&mailbox->status) != IPC_FW_TXLOW)
594 		goto update_end;
595 	buffer = buffer + 0x800;
596 	memcpy_toio(fw_update_base, buffer, 0x20000);
597 	writel(1, &mailbox->driver_flag);
598 	while (readl(&mailbox->scu_flag) == 1) {
599 		rmb();
600 		mdelay(1);
601 	}
602 
603 	/* check for 'BADN' */
604 	if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
605 		goto update_end;
606 
607 	while (readl(&mailbox->status) != IPC_FW_TXHIGH) {
608 		rmb();
609 		mdelay(10);
610 	}
611 	mdelay(10);
612 
613 	if (readl(&mailbox->status) != IPC_FW_TXHIGH)
614 		goto update_end;
615 
616 	buffer = buffer + 0x20000;
617 	memcpy_toio(fw_update_base, buffer, 0x20000);
618 	writel(0, &mailbox->driver_flag);
619 
620 	while (mailbox->scu_flag == 0) {
621 		rmb();
622 		mdelay(1);
623 	}
624 
625 	/* check for 'BADN' */
626 	if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
627 		goto update_end;
628 
629 	if (readl(&mailbox->status) == IPC_FW_TXLOW) {
630 		++retry_cnt;
631 		goto update_retry;
632 	}
633 
634 update_end:
635 	status = readl(&mailbox->status);
636 
637 	iounmap(fw_update_base);
638 	iounmap(mailbox);
639 	mutex_unlock(&ipclock);
640 
641 	if (status == IPC_FW_UPDATE_SUCCESS)
642 		return 0;
643 	return -EIO;
644 }
645 EXPORT_SYMBOL(intel_scu_ipc_fw_update);
646 
647 /*
648  * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
649  * When ioc bit is set to 1, caller api must wait for interrupt handler called
650  * which in turn unlocks the caller api. Currently this is not used
651  *
652  * This is edge triggered so we need take no action to clear anything
653  */
ioc(int irq,void * dev_id)654 static irqreturn_t ioc(int irq, void *dev_id)
655 {
656 	return IRQ_HANDLED;
657 }
658 
659 /**
660  *	ipc_probe	-	probe an Intel SCU IPC
661  *	@dev: the PCI device matching
662  *	@id: entry in the match table
663  *
664  *	Enable and install an intel SCU IPC. This appears in the PCI space
665  *	but uses some hard coded addresses as well.
666  */
ipc_probe(struct pci_dev * dev,const struct pci_device_id * id)667 static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
668 {
669 	int err;
670 	resource_size_t pci_resource;
671 
672 	if (ipcdev.pdev)		/* We support only one SCU */
673 		return -EBUSY;
674 
675 	ipcdev.pdev = pci_dev_get(dev);
676 
677 	err = pci_enable_device(dev);
678 	if (err)
679 		return err;
680 
681 	err = pci_request_regions(dev, "intel_scu_ipc");
682 	if (err)
683 		return err;
684 
685 	pci_resource = pci_resource_start(dev, 0);
686 	if (!pci_resource)
687 		return -ENOMEM;
688 
689 	if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
690 		return -EBUSY;
691 
692 	ipcdev.ipc_base = ioremap_nocache(IPC_BASE_ADDR, IPC_MAX_ADDR);
693 	if (!ipcdev.ipc_base)
694 		return -ENOMEM;
695 
696 	ipcdev.i2c_base = ioremap_nocache(IPC_I2C_BASE, IPC_I2C_MAX_ADDR);
697 	if (!ipcdev.i2c_base) {
698 		iounmap(ipcdev.ipc_base);
699 		return -ENOMEM;
700 	}
701 
702 	intel_scu_devices_create();
703 
704 	return 0;
705 }
706 
707 /**
708  *	ipc_remove	-	remove a bound IPC device
709  *	@pdev: PCI device
710  *
711  *	In practice the SCU is not removable but this function is also
712  *	called for each device on a module unload or cleanup which is the
713  *	path that will get used.
714  *
715  *	Free up the mappings and release the PCI resources
716  */
ipc_remove(struct pci_dev * pdev)717 static void ipc_remove(struct pci_dev *pdev)
718 {
719 	free_irq(pdev->irq, &ipcdev);
720 	pci_release_regions(pdev);
721 	pci_dev_put(ipcdev.pdev);
722 	iounmap(ipcdev.ipc_base);
723 	iounmap(ipcdev.i2c_base);
724 	ipcdev.pdev = NULL;
725 	intel_scu_devices_destroy();
726 }
727 
728 static const struct pci_device_id pci_ids[] = {
729 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080e)},
730 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x082a)},
731 	{ 0,}
732 };
733 MODULE_DEVICE_TABLE(pci, pci_ids);
734 
735 static struct pci_driver ipc_driver = {
736 	.name = "intel_scu_ipc",
737 	.id_table = pci_ids,
738 	.probe = ipc_probe,
739 	.remove = ipc_remove,
740 };
741 
742 
intel_scu_ipc_init(void)743 static int __init intel_scu_ipc_init(void)
744 {
745 	platform = mrst_identify_cpu();
746 	if (platform == 0)
747 		return -ENODEV;
748 	return  pci_register_driver(&ipc_driver);
749 }
750 
intel_scu_ipc_exit(void)751 static void __exit intel_scu_ipc_exit(void)
752 {
753 	pci_unregister_driver(&ipc_driver);
754 }
755 
756 MODULE_AUTHOR("Sreedhara DS <sreedhara.ds@intel.com>");
757 MODULE_DESCRIPTION("Intel SCU IPC driver");
758 MODULE_LICENSE("GPL");
759 
760 module_init(intel_scu_ipc_init);
761 module_exit(intel_scu_ipc_exit);
762