tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
88struct ks8995_pdata {
89 /* not yet implemented */
90};
91
92struct ks8995_switch {
93 struct spi_device *spi;
94 struct mutex lock;
95 struct ks8995_pdata *pdata;
96};
97
98static inline u8 get_chip_id(u8 val)
99{
100 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
101}
102
103static inline u8 get_chip_rev(u8 val)
104{
105 return (val >> ID1_REVISION_S) & ID1_REVISION_M;
106}
107
108/* ------------------------------------------------------------------------ */
109static 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
140static 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
170static 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
175static 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
184static int ks8995_stop(struct ks8995_switch *ks)
185{
186 return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
187}
188
189static int ks8995_start(struct ks8995_switch *ks)
190{
191 return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
192}
193
194static 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
209static 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
231static 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
253static 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
265static 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
327err_drvdata:
328 dev_set_drvdata(&spi->dev, NULL);
329 kfree(ks);
330 return err;
331}
332
333static 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
348static struct spi_driver ks8995_driver = {
349 .driver = {
350 .name = "spi-ks8995",
351 .owner = THIS_MODULE,
352 },
353 .probe = ks8995_probe,
354 .remove = __devexit_p(ks8995_remove),
355};
356
357static int __init ks8995_init(void)
358{
359 printk(KERN_INFO DRV_DESC " version " DRV_VERSION"\n");
360
361 return spi_register_driver(&ks8995_driver);
362}
363module_init(ks8995_init);
364
365static void __exit ks8995_exit(void)
366{
367 spi_unregister_driver(&ks8995_driver);
368}
369module_exit(ks8995_exit);
370
371MODULE_DESCRIPTION(DRV_DESC);
372MODULE_VERSION(DRV_VERSION);
373MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
374MODULE_LICENSE("GPL v2");