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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/delay.h>
21 #include <linux/device.h>
22
23 #include <linux/spi/spi.h>
24
25 #define DRV_VERSION "0.1.1"
26 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
27
28 /* ------------------------------------------------------------------------ */
29
30 #define KS8995_REG_ID0 0x00 /* Chip ID0 */
31 #define KS8995_REG_ID1 0x01 /* Chip ID1 */
32
33 #define KS8995_REG_GC0 0x02 /* Global Control 0 */
34 #define KS8995_REG_GC1 0x03 /* Global Control 1 */
35 #define KS8995_REG_GC2 0x04 /* Global Control 2 */
36 #define KS8995_REG_GC3 0x05 /* Global Control 3 */
37 #define KS8995_REG_GC4 0x06 /* Global Control 4 */
38 #define KS8995_REG_GC5 0x07 /* Global Control 5 */
39 #define KS8995_REG_GC6 0x08 /* Global Control 6 */
40 #define KS8995_REG_GC7 0x09 /* Global Control 7 */
41 #define KS8995_REG_GC8 0x0a /* Global Control 8 */
42 #define KS8995_REG_GC9 0x0b /* Global Control 9 */
43
44 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
45 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
46
47 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
48 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
49 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */
50 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */
51 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */
52 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */
53 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */
54 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */
55
56 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */
57 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */
58 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */
59 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */
60 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */
61 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */
62
63 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */
64 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */
65 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */
66 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */
67 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */
68 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */
69 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */
70 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */
71 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */
72 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */
73
74 #define KS8995_REGS_SIZE 0x80
75
76 #define ID1_CHIPID_M 0xf
77 #define ID1_CHIPID_S 4
78 #define ID1_REVISION_M 0x7
79 #define ID1_REVISION_S 1
80 #define ID1_START_SW 1 /* start the switch */
81
82 #define FAMILY_KS8995 0x95
83 #define CHIPID_M 0
84
85 #define KS8995_CMD_WRITE 0x02U
86 #define KS8995_CMD_READ 0x03U
87
88 #define KS8995_RESET_DELAY 10 /* usec */
89
90 struct ks8995_pdata {
91 /* not yet implemented */
92 };
93
94 struct ks8995_switch {
95 struct spi_device *spi;
96 struct mutex lock;
97 struct ks8995_pdata *pdata;
98 };
99
get_chip_id(u8 val)100 static inline u8 get_chip_id(u8 val)
101 {
102 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
103 }
104
get_chip_rev(u8 val)105 static inline u8 get_chip_rev(u8 val)
106 {
107 return (val >> ID1_REVISION_S) & ID1_REVISION_M;
108 }
109
110 /* ------------------------------------------------------------------------ */
ks8995_read(struct ks8995_switch * ks,char * buf,unsigned offset,size_t count)111 static int ks8995_read(struct ks8995_switch *ks, char *buf,
112 unsigned offset, size_t count)
113 {
114 u8 cmd[2];
115 struct spi_transfer t[2];
116 struct spi_message m;
117 int err;
118
119 spi_message_init(&m);
120
121 memset(&t, 0, sizeof(t));
122
123 t[0].tx_buf = cmd;
124 t[0].len = sizeof(cmd);
125 spi_message_add_tail(&t[0], &m);
126
127 t[1].rx_buf = buf;
128 t[1].len = count;
129 spi_message_add_tail(&t[1], &m);
130
131 cmd[0] = KS8995_CMD_READ;
132 cmd[1] = offset;
133
134 mutex_lock(&ks->lock);
135 err = spi_sync(ks->spi, &m);
136 mutex_unlock(&ks->lock);
137
138 return err ? err : count;
139 }
140
141
ks8995_write(struct ks8995_switch * ks,char * buf,unsigned offset,size_t count)142 static int ks8995_write(struct ks8995_switch *ks, char *buf,
143 unsigned offset, size_t count)
144 {
145 u8 cmd[2];
146 struct spi_transfer t[2];
147 struct spi_message m;
148 int err;
149
150 spi_message_init(&m);
151
152 memset(&t, 0, sizeof(t));
153
154 t[0].tx_buf = cmd;
155 t[0].len = sizeof(cmd);
156 spi_message_add_tail(&t[0], &m);
157
158 t[1].tx_buf = buf;
159 t[1].len = count;
160 spi_message_add_tail(&t[1], &m);
161
162 cmd[0] = KS8995_CMD_WRITE;
163 cmd[1] = offset;
164
165 mutex_lock(&ks->lock);
166 err = spi_sync(ks->spi, &m);
167 mutex_unlock(&ks->lock);
168
169 return err ? err : count;
170 }
171
ks8995_read_reg(struct ks8995_switch * ks,u8 addr,u8 * buf)172 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
173 {
174 return (ks8995_read(ks, buf, addr, 1) != 1);
175 }
176
ks8995_write_reg(struct ks8995_switch * ks,u8 addr,u8 val)177 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
178 {
179 char buf = val;
180
181 return (ks8995_write(ks, &buf, addr, 1) != 1);
182 }
183
184 /* ------------------------------------------------------------------------ */
185
ks8995_stop(struct ks8995_switch * ks)186 static int ks8995_stop(struct ks8995_switch *ks)
187 {
188 return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
189 }
190
ks8995_start(struct ks8995_switch * ks)191 static int ks8995_start(struct ks8995_switch *ks)
192 {
193 return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
194 }
195
ks8995_reset(struct ks8995_switch * ks)196 static int ks8995_reset(struct ks8995_switch *ks)
197 {
198 int err;
199
200 err = ks8995_stop(ks);
201 if (err)
202 return err;
203
204 udelay(KS8995_RESET_DELAY);
205
206 return ks8995_start(ks);
207 }
208
209 /* ------------------------------------------------------------------------ */
210
ks8995_registers_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)211 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
212 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
213 {
214 struct device *dev;
215 struct ks8995_switch *ks8995;
216
217 dev = container_of(kobj, struct device, kobj);
218 ks8995 = dev_get_drvdata(dev);
219
220 if (unlikely(off > KS8995_REGS_SIZE))
221 return 0;
222
223 if ((off + count) > KS8995_REGS_SIZE)
224 count = KS8995_REGS_SIZE - off;
225
226 if (unlikely(!count))
227 return count;
228
229 return ks8995_read(ks8995, buf, off, count);
230 }
231
232
ks8995_registers_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)233 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
234 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
235 {
236 struct device *dev;
237 struct ks8995_switch *ks8995;
238
239 dev = container_of(kobj, struct device, kobj);
240 ks8995 = dev_get_drvdata(dev);
241
242 if (unlikely(off >= KS8995_REGS_SIZE))
243 return -EFBIG;
244
245 if ((off + count) > KS8995_REGS_SIZE)
246 count = KS8995_REGS_SIZE - off;
247
248 if (unlikely(!count))
249 return count;
250
251 return ks8995_write(ks8995, buf, off, count);
252 }
253
254
255 static struct bin_attribute ks8995_registers_attr = {
256 .attr = {
257 .name = "registers",
258 .mode = S_IRUSR | S_IWUSR,
259 },
260 .size = KS8995_REGS_SIZE,
261 .read = ks8995_registers_read,
262 .write = ks8995_registers_write,
263 };
264
265 /* ------------------------------------------------------------------------ */
266
ks8995_probe(struct spi_device * spi)267 static int ks8995_probe(struct spi_device *spi)
268 {
269 struct ks8995_switch *ks;
270 struct ks8995_pdata *pdata;
271 u8 ids[2];
272 int err;
273
274 /* Chip description */
275 pdata = spi->dev.platform_data;
276
277 ks = kzalloc(sizeof(*ks), GFP_KERNEL);
278 if (!ks)
279 return -ENOMEM;
280
281 mutex_init(&ks->lock);
282 ks->pdata = pdata;
283 ks->spi = spi_dev_get(spi);
284 spi_set_drvdata(spi, 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 spi_set_drvdata(spi, NULL);
329 kfree(ks);
330 return err;
331 }
332
ks8995_remove(struct spi_device * spi)333 static int ks8995_remove(struct spi_device *spi)
334 {
335 struct ks8995_data *ks8995;
336
337 ks8995 = spi_get_drvdata(spi);
338 sysfs_remove_bin_file(&spi->dev.kobj, &ks8995_registers_attr);
339
340 spi_set_drvdata(spi, 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 .owner = THIS_MODULE,
352 },
353 .probe = ks8995_probe,
354 .remove = ks8995_remove,
355 };
356
ks8995_init(void)357 static int __init ks8995_init(void)
358 {
359 pr_info(DRV_DESC " version " DRV_VERSION "\n");
360
361 return spi_register_driver(&ks8995_driver);
362 }
363 module_init(ks8995_init);
364
ks8995_exit(void)365 static void __exit ks8995_exit(void)
366 {
367 spi_unregister_driver(&ks8995_driver);
368 }
369 module_exit(ks8995_exit);
370
371 MODULE_DESCRIPTION(DRV_DESC);
372 MODULE_VERSION(DRV_VERSION);
373 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
374 MODULE_LICENSE("GPL v2");
375