1 /*
2 * SPI driver for Micrel/Kendin KS8995M ethernet switch
3 *
4 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
5 *
6 * This file was based on: drivers/spi/at25.c
7 * Copyright (C) 2006 David Brownell
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as published
11 * by the Free Software Foundation.
12 */
13
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/delay.h>
19 #include <linux/device.h>
20
21 #include <linux/spi/spi.h>
22
23 #define DRV_VERSION "0.1.1"
24 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
25
26 /* ------------------------------------------------------------------------ */
27
28 #define KS8995_REG_ID0 0x00 /* Chip ID0 */
29 #define KS8995_REG_ID1 0x01 /* Chip ID1 */
30
31 #define KS8995_REG_GC0 0x02 /* Global Control 0 */
32 #define KS8995_REG_GC1 0x03 /* Global Control 1 */
33 #define KS8995_REG_GC2 0x04 /* Global Control 2 */
34 #define KS8995_REG_GC3 0x05 /* Global Control 3 */
35 #define KS8995_REG_GC4 0x06 /* Global Control 4 */
36 #define KS8995_REG_GC5 0x07 /* Global Control 5 */
37 #define KS8995_REG_GC6 0x08 /* Global Control 6 */
38 #define KS8995_REG_GC7 0x09 /* Global Control 7 */
39 #define KS8995_REG_GC8 0x0a /* Global Control 8 */
40 #define KS8995_REG_GC9 0x0b /* Global Control 9 */
41
42 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
43 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
44
45 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
46 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
47 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */
48 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */
49 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */
50 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */
51 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */
52 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */
53
54 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */
55 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */
56 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */
57 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */
58 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */
59 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */
60
61 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */
62 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */
63 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */
64 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */
65 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */
66 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */
67 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */
68 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */
69 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */
70 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */
71
72 #define KS8995_REGS_SIZE 0x80
73
74 #define ID1_CHIPID_M 0xf
75 #define ID1_CHIPID_S 4
76 #define ID1_REVISION_M 0x7
77 #define ID1_REVISION_S 1
78 #define ID1_START_SW 1 /* start the switch */
79
80 #define FAMILY_KS8995 0x95
81 #define CHIPID_M 0
82
83 #define KS8995_CMD_WRITE 0x02U
84 #define KS8995_CMD_READ 0x03U
85
86 #define KS8995_RESET_DELAY 10 /* usec */
87
88 struct ks8995_pdata {
89 /* not yet implemented */
90 };
91
92 struct ks8995_switch {
93 struct spi_device *spi;
94 struct mutex lock;
95 struct ks8995_pdata *pdata;
96 };
97
get_chip_id(u8 val)98 static inline u8 get_chip_id(u8 val)
99 {
100 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
101 }
102
get_chip_rev(u8 val)103 static inline u8 get_chip_rev(u8 val)
104 {
105 return (val >> ID1_REVISION_S) & ID1_REVISION_M;
106 }
107
108 /* ------------------------------------------------------------------------ */
ks8995_read(struct ks8995_switch * ks,char * buf,unsigned offset,size_t count)109 static int ks8995_read(struct ks8995_switch *ks, char *buf,
110 unsigned offset, size_t count)
111 {
112 u8 cmd[2];
113 struct spi_transfer t[2];
114 struct spi_message m;
115 int err;
116
117 spi_message_init(&m);
118
119 memset(&t, 0, sizeof(t));
120
121 t[0].tx_buf = cmd;
122 t[0].len = sizeof(cmd);
123 spi_message_add_tail(&t[0], &m);
124
125 t[1].rx_buf = buf;
126 t[1].len = count;
127 spi_message_add_tail(&t[1], &m);
128
129 cmd[0] = KS8995_CMD_READ;
130 cmd[1] = offset;
131
132 mutex_lock(&ks->lock);
133 err = spi_sync(ks->spi, &m);
134 mutex_unlock(&ks->lock);
135
136 return err ? err : count;
137 }
138
139
ks8995_write(struct ks8995_switch * ks,char * buf,unsigned offset,size_t count)140 static int ks8995_write(struct ks8995_switch *ks, char *buf,
141 unsigned offset, size_t count)
142 {
143 u8 cmd[2];
144 struct spi_transfer t[2];
145 struct spi_message m;
146 int err;
147
148 spi_message_init(&m);
149
150 memset(&t, 0, sizeof(t));
151
152 t[0].tx_buf = cmd;
153 t[0].len = sizeof(cmd);
154 spi_message_add_tail(&t[0], &m);
155
156 t[1].tx_buf = buf;
157 t[1].len = count;
158 spi_message_add_tail(&t[1], &m);
159
160 cmd[0] = KS8995_CMD_WRITE;
161 cmd[1] = offset;
162
163 mutex_lock(&ks->lock);
164 err = spi_sync(ks->spi, &m);
165 mutex_unlock(&ks->lock);
166
167 return err ? err : count;
168 }
169
ks8995_read_reg(struct ks8995_switch * ks,u8 addr,u8 * buf)170 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
171 {
172 return (ks8995_read(ks, buf, addr, 1) != 1);
173 }
174
ks8995_write_reg(struct ks8995_switch * ks,u8 addr,u8 val)175 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
176 {
177 char buf = val;
178
179 return (ks8995_write(ks, &buf, addr, 1) != 1);
180 }
181
182 /* ------------------------------------------------------------------------ */
183
ks8995_stop(struct ks8995_switch * ks)184 static int ks8995_stop(struct ks8995_switch *ks)
185 {
186 return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
187 }
188
ks8995_start(struct ks8995_switch * ks)189 static int ks8995_start(struct ks8995_switch *ks)
190 {
191 return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
192 }
193
ks8995_reset(struct ks8995_switch * ks)194 static int ks8995_reset(struct ks8995_switch *ks)
195 {
196 int err;
197
198 err = ks8995_stop(ks);
199 if (err)
200 return err;
201
202 udelay(KS8995_RESET_DELAY);
203
204 return ks8995_start(ks);
205 }
206
207 /* ------------------------------------------------------------------------ */
208
ks8995_registers_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)209 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
210 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
211 {
212 struct device *dev;
213 struct ks8995_switch *ks8995;
214
215 dev = container_of(kobj, struct device, kobj);
216 ks8995 = dev_get_drvdata(dev);
217
218 if (unlikely(off > KS8995_REGS_SIZE))
219 return 0;
220
221 if ((off + count) > KS8995_REGS_SIZE)
222 count = KS8995_REGS_SIZE - off;
223
224 if (unlikely(!count))
225 return count;
226
227 return ks8995_read(ks8995, buf, off, count);
228 }
229
230
ks8995_registers_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)231 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
232 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
233 {
234 struct device *dev;
235 struct ks8995_switch *ks8995;
236
237 dev = container_of(kobj, struct device, kobj);
238 ks8995 = dev_get_drvdata(dev);
239
240 if (unlikely(off >= KS8995_REGS_SIZE))
241 return -EFBIG;
242
243 if ((off + count) > KS8995_REGS_SIZE)
244 count = KS8995_REGS_SIZE - off;
245
246 if (unlikely(!count))
247 return count;
248
249 return ks8995_write(ks8995, buf, off, count);
250 }
251
252
253 static struct bin_attribute ks8995_registers_attr = {
254 .attr = {
255 .name = "registers",
256 .mode = S_IRUSR | S_IWUSR,
257 },
258 .size = KS8995_REGS_SIZE,
259 .read = ks8995_registers_read,
260 .write = ks8995_registers_write,
261 };
262
263 /* ------------------------------------------------------------------------ */
264
ks8995_probe(struct spi_device * spi)265 static int __devinit ks8995_probe(struct spi_device *spi)
266 {
267 struct ks8995_switch *ks;
268 struct ks8995_pdata *pdata;
269 u8 ids[2];
270 int err;
271
272 /* Chip description */
273 pdata = spi->dev.platform_data;
274
275 ks = kzalloc(sizeof(*ks), GFP_KERNEL);
276 if (!ks) {
277 dev_err(&spi->dev, "no memory for private data\n");
278 return -ENOMEM;
279 }
280
281 mutex_init(&ks->lock);
282 ks->pdata = pdata;
283 ks->spi = spi_dev_get(spi);
284 dev_set_drvdata(&spi->dev, ks);
285
286 spi->mode = SPI_MODE_0;
287 spi->bits_per_word = 8;
288 err = spi_setup(spi);
289 if (err) {
290 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
291 goto err_drvdata;
292 }
293
294 err = ks8995_read(ks, ids, KS8995_REG_ID0, sizeof(ids));
295 if (err < 0) {
296 dev_err(&spi->dev, "unable to read id registers, err=%d\n",
297 err);
298 goto err_drvdata;
299 }
300
301 switch (ids[0]) {
302 case FAMILY_KS8995:
303 break;
304 default:
305 dev_err(&spi->dev, "unknown family id:%02x\n", ids[0]);
306 err = -ENODEV;
307 goto err_drvdata;
308 }
309
310 err = ks8995_reset(ks);
311 if (err)
312 goto err_drvdata;
313
314 err = sysfs_create_bin_file(&spi->dev.kobj, &ks8995_registers_attr);
315 if (err) {
316 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
317 err);
318 goto err_drvdata;
319 }
320
321 dev_info(&spi->dev, "KS89%02X device found, Chip ID:%01x, "
322 "Revision:%01x\n", ids[0],
323 get_chip_id(ids[1]), get_chip_rev(ids[1]));
324
325 return 0;
326
327 err_drvdata:
328 dev_set_drvdata(&spi->dev, NULL);
329 kfree(ks);
330 return err;
331 }
332
ks8995_remove(struct spi_device * spi)333 static int __devexit ks8995_remove(struct spi_device *spi)
334 {
335 struct ks8995_data *ks8995;
336
337 ks8995 = dev_get_drvdata(&spi->dev);
338 sysfs_remove_bin_file(&spi->dev.kobj, &ks8995_registers_attr);
339
340 dev_set_drvdata(&spi->dev, NULL);
341 kfree(ks8995);
342
343 return 0;
344 }
345
346 /* ------------------------------------------------------------------------ */
347
348 static struct spi_driver ks8995_driver = {
349 .driver = {
350 .name = "spi-ks8995",
351 .bus = &spi_bus_type,
352 .owner = THIS_MODULE,
353 },
354 .probe = ks8995_probe,
355 .remove = __devexit_p(ks8995_remove),
356 };
357
ks8995_init(void)358 static int __init ks8995_init(void)
359 {
360 printk(KERN_INFO DRV_DESC " version " DRV_VERSION"\n");
361
362 return spi_register_driver(&ks8995_driver);
363 }
364 module_init(ks8995_init);
365
ks8995_exit(void)366 static void __exit ks8995_exit(void)
367 {
368 spi_unregister_driver(&ks8995_driver);
369 }
370 module_exit(ks8995_exit);
371
372 MODULE_DESCRIPTION(DRV_DESC);
373 MODULE_VERSION(DRV_VERSION);
374 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
375 MODULE_LICENSE("GPL v2");
376