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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
4 *
5 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
6 *
7 * This file was based on: drivers/spi/at25.c
8 * Copyright (C) 2006 David Brownell
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/types.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/delay.h>
17#include <linux/device.h>
18#include <linux/gpio/consumer.h>
19#include <linux/of.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 KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */
73
74#define KS8995_REGS_SIZE 0x80
75#define KSZ8864_REGS_SIZE 0x100
76#define KSZ8795_REGS_SIZE 0x100
77
78#define ID1_CHIPID_M 0xf
79#define ID1_CHIPID_S 4
80#define ID1_REVISION_M 0x7
81#define ID1_REVISION_S 1
82#define ID1_START_SW 1 /* start the switch */
83
84#define FAMILY_KS8995 0x95
85#define FAMILY_KSZ8795 0x87
86#define CHIPID_M 0
87#define KS8995_CHIP_ID 0x00
88#define KSZ8864_CHIP_ID 0x01
89#define KSZ8795_CHIP_ID 0x09
90
91#define KS8995_CMD_WRITE 0x02U
92#define KS8995_CMD_READ 0x03U
93
94#define KS8995_RESET_DELAY 10 /* usec */
95
96enum ks8995_chip_variant {
97 ks8995,
98 ksz8864,
99 ksz8795,
100 max_variant
101};
102
103struct ks8995_chip_params {
104 char *name;
105 int family_id;
106 int chip_id;
107 int regs_size;
108 int addr_width;
109 int addr_shift;
110};
111
112static const struct ks8995_chip_params ks8995_chip[] = {
113 [ks8995] = {
114 .name = "KS8995MA",
115 .family_id = FAMILY_KS8995,
116 .chip_id = KS8995_CHIP_ID,
117 .regs_size = KS8995_REGS_SIZE,
118 .addr_width = 8,
119 .addr_shift = 0,
120 },
121 [ksz8864] = {
122 .name = "KSZ8864RMN",
123 .family_id = FAMILY_KS8995,
124 .chip_id = KSZ8864_CHIP_ID,
125 .regs_size = KSZ8864_REGS_SIZE,
126 .addr_width = 8,
127 .addr_shift = 0,
128 },
129 [ksz8795] = {
130 .name = "KSZ8795CLX",
131 .family_id = FAMILY_KSZ8795,
132 .chip_id = KSZ8795_CHIP_ID,
133 .regs_size = KSZ8795_REGS_SIZE,
134 .addr_width = 12,
135 .addr_shift = 1,
136 },
137};
138
139struct ks8995_switch {
140 struct spi_device *spi;
141 struct mutex lock;
142 struct gpio_desc *reset_gpio;
143 struct bin_attribute regs_attr;
144 const struct ks8995_chip_params *chip;
145 int revision_id;
146};
147
148static const struct spi_device_id ks8995_id[] = {
149 {"ks8995", ks8995},
150 {"ksz8864", ksz8864},
151 {"ksz8795", ksz8795},
152 { }
153};
154MODULE_DEVICE_TABLE(spi, ks8995_id);
155
156static const struct of_device_id ks8895_spi_of_match[] = {
157 { .compatible = "micrel,ks8995" },
158 { .compatible = "micrel,ksz8864" },
159 { .compatible = "micrel,ksz8795" },
160 { },
161};
162MODULE_DEVICE_TABLE(of, ks8895_spi_of_match);
163
164static inline u8 get_chip_id(u8 val)
165{
166 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
167}
168
169static inline u8 get_chip_rev(u8 val)
170{
171 return (val >> ID1_REVISION_S) & ID1_REVISION_M;
172}
173
174/* create_spi_cmd - create a chip specific SPI command header
175 * @ks: pointer to switch instance
176 * @cmd: SPI command for switch
177 * @address: register address for command
178 *
179 * Different chip families use different bit pattern to address the switches
180 * registers:
181 *
182 * KS8995: 8bit command + 8bit address
183 * KSZ8795: 3bit command + 12bit address + 1bit TR (?)
184 */
185static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
186 unsigned address)
187{
188 u16 result = cmd;
189
190 /* make room for address (incl. address shift) */
191 result <<= ks->chip->addr_width + ks->chip->addr_shift;
192 /* add address */
193 result |= address << ks->chip->addr_shift;
194 /* SPI protocol needs big endian */
195 return cpu_to_be16(result);
196}
197/* ------------------------------------------------------------------------ */
198static int ks8995_read(struct ks8995_switch *ks, char *buf,
199 unsigned offset, size_t count)
200{
201 __be16 cmd;
202 struct spi_transfer t[2];
203 struct spi_message m;
204 int err;
205
206 cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
207 spi_message_init(&m);
208
209 memset(&t, 0, sizeof(t));
210
211 t[0].tx_buf = &cmd;
212 t[0].len = sizeof(cmd);
213 spi_message_add_tail(&t[0], &m);
214
215 t[1].rx_buf = buf;
216 t[1].len = count;
217 spi_message_add_tail(&t[1], &m);
218
219 mutex_lock(&ks->lock);
220 err = spi_sync(ks->spi, &m);
221 mutex_unlock(&ks->lock);
222
223 return err ? err : count;
224}
225
226static int ks8995_write(struct ks8995_switch *ks, char *buf,
227 unsigned offset, size_t count)
228{
229 __be16 cmd;
230 struct spi_transfer t[2];
231 struct spi_message m;
232 int err;
233
234 cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
235 spi_message_init(&m);
236
237 memset(&t, 0, sizeof(t));
238
239 t[0].tx_buf = &cmd;
240 t[0].len = sizeof(cmd);
241 spi_message_add_tail(&t[0], &m);
242
243 t[1].tx_buf = buf;
244 t[1].len = count;
245 spi_message_add_tail(&t[1], &m);
246
247 mutex_lock(&ks->lock);
248 err = spi_sync(ks->spi, &m);
249 mutex_unlock(&ks->lock);
250
251 return err ? err : count;
252}
253
254static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
255{
256 return ks8995_read(ks, buf, addr, 1) != 1;
257}
258
259static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
260{
261 char buf = val;
262
263 return ks8995_write(ks, &buf, addr, 1) != 1;
264}
265
266/* ------------------------------------------------------------------------ */
267
268static int ks8995_stop(struct ks8995_switch *ks)
269{
270 return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
271}
272
273static int ks8995_start(struct ks8995_switch *ks)
274{
275 return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
276}
277
278static int ks8995_reset(struct ks8995_switch *ks)
279{
280 int err;
281
282 err = ks8995_stop(ks);
283 if (err)
284 return err;
285
286 udelay(KS8995_RESET_DELAY);
287
288 return ks8995_start(ks);
289}
290
291static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
292 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
293{
294 struct device *dev;
295 struct ks8995_switch *ks8995;
296
297 dev = kobj_to_dev(kobj);
298 ks8995 = dev_get_drvdata(dev);
299
300 return ks8995_read(ks8995, buf, off, count);
301}
302
303static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
304 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
305{
306 struct device *dev;
307 struct ks8995_switch *ks8995;
308
309 dev = kobj_to_dev(kobj);
310 ks8995 = dev_get_drvdata(dev);
311
312 return ks8995_write(ks8995, buf, off, count);
313}
314
315/* ks8995_get_revision - get chip revision
316 * @ks: pointer to switch instance
317 *
318 * Verify chip family and id and get chip revision.
319 */
320static int ks8995_get_revision(struct ks8995_switch *ks)
321{
322 int err;
323 u8 id0, id1, ksz8864_id;
324
325 /* read family id */
326 err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
327 if (err) {
328 err = -EIO;
329 goto err_out;
330 }
331
332 /* verify family id */
333 if (id0 != ks->chip->family_id) {
334 dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
335 ks->chip->family_id, id0);
336 err = -ENODEV;
337 goto err_out;
338 }
339
340 switch (ks->chip->family_id) {
341 case FAMILY_KS8995:
342 /* try reading chip id at CHIP ID1 */
343 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
344 if (err) {
345 err = -EIO;
346 goto err_out;
347 }
348
349 /* verify chip id */
350 if ((get_chip_id(id1) == CHIPID_M) &&
351 (get_chip_id(id1) == ks->chip->chip_id)) {
352 /* KS8995MA */
353 ks->revision_id = get_chip_rev(id1);
354 } else if (get_chip_id(id1) != CHIPID_M) {
355 /* KSZ8864RMN */
356 err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
357 if (err) {
358 err = -EIO;
359 goto err_out;
360 }
361
362 if ((ksz8864_id & 0x80) &&
363 (ks->chip->chip_id == KSZ8864_CHIP_ID)) {
364 ks->revision_id = get_chip_rev(id1);
365 }
366
367 } else {
368 dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
369 id1);
370 err = -ENODEV;
371 }
372 break;
373 case FAMILY_KSZ8795:
374 /* try reading chip id at CHIP ID1 */
375 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
376 if (err) {
377 err = -EIO;
378 goto err_out;
379 }
380
381 if (get_chip_id(id1) == ks->chip->chip_id) {
382 ks->revision_id = get_chip_rev(id1);
383 } else {
384 dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
385 id1);
386 err = -ENODEV;
387 }
388 break;
389 default:
390 dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
391 err = -ENODEV;
392 break;
393 }
394err_out:
395 return err;
396}
397
398static const struct bin_attribute ks8995_registers_attr = {
399 .attr = {
400 .name = "registers",
401 .mode = 0600,
402 },
403 .size = KS8995_REGS_SIZE,
404 .read = ks8995_registers_read,
405 .write = ks8995_registers_write,
406};
407
408/* ------------------------------------------------------------------------ */
409static int ks8995_probe(struct spi_device *spi)
410{
411 struct ks8995_switch *ks;
412 int err;
413 int variant = spi_get_device_id(spi)->driver_data;
414
415 if (variant >= max_variant) {
416 dev_err(&spi->dev, "bad chip variant %d\n", variant);
417 return -ENODEV;
418 }
419
420 ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
421 if (!ks)
422 return -ENOMEM;
423
424 mutex_init(&ks->lock);
425 ks->spi = spi;
426 ks->chip = &ks8995_chip[variant];
427
428 ks->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
429 GPIOD_OUT_HIGH);
430 err = PTR_ERR_OR_ZERO(ks->reset_gpio);
431 if (err) {
432 dev_err(&spi->dev,
433 "failed to get reset gpio: %d\n", err);
434 return err;
435 }
436
437 err = gpiod_set_consumer_name(ks->reset_gpio, "switch-reset");
438 if (err)
439 return err;
440
441 /* de-assert switch reset */
442 /* FIXME: this likely requires a delay */
443 gpiod_set_value_cansleep(ks->reset_gpio, 0);
444
445 spi_set_drvdata(spi, ks);
446
447 spi->mode = SPI_MODE_0;
448 spi->bits_per_word = 8;
449 err = spi_setup(spi);
450 if (err) {
451 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
452 return err;
453 }
454
455 err = ks8995_get_revision(ks);
456 if (err)
457 return err;
458
459 memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
460 ks->regs_attr.size = ks->chip->regs_size;
461
462 err = ks8995_reset(ks);
463 if (err)
464 return err;
465
466 sysfs_attr_init(&ks->regs_attr.attr);
467 err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
468 if (err) {
469 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
470 err);
471 return err;
472 }
473
474 dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
475 ks->chip->name, ks->chip->chip_id, ks->revision_id);
476
477 return 0;
478}
479
480static void ks8995_remove(struct spi_device *spi)
481{
482 struct ks8995_switch *ks = spi_get_drvdata(spi);
483
484 sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);
485
486 /* assert reset */
487 gpiod_set_value_cansleep(ks->reset_gpio, 1);
488}
489
490/* ------------------------------------------------------------------------ */
491static struct spi_driver ks8995_driver = {
492 .driver = {
493 .name = "spi-ks8995",
494 .of_match_table = ks8895_spi_of_match,
495 },
496 .probe = ks8995_probe,
497 .remove = ks8995_remove,
498 .id_table = ks8995_id,
499};
500
501module_spi_driver(ks8995_driver);
502
503MODULE_DESCRIPTION(DRV_DESC);
504MODULE_VERSION(DRV_VERSION);
505MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
506MODULE_LICENSE("GPL v2");
1/*
2 * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
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/module.h>
19#include <linux/delay.h>
20#include <linux/device.h>
21#include <linux/gpio/consumer.h>
22#include <linux/of.h>
23#include <linux/of_gpio.h>
24
25#include <linux/spi/spi.h>
26
27#define DRV_VERSION "0.1.1"
28#define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
29
30/* ------------------------------------------------------------------------ */
31
32#define KS8995_REG_ID0 0x00 /* Chip ID0 */
33#define KS8995_REG_ID1 0x01 /* Chip ID1 */
34
35#define KS8995_REG_GC0 0x02 /* Global Control 0 */
36#define KS8995_REG_GC1 0x03 /* Global Control 1 */
37#define KS8995_REG_GC2 0x04 /* Global Control 2 */
38#define KS8995_REG_GC3 0x05 /* Global Control 3 */
39#define KS8995_REG_GC4 0x06 /* Global Control 4 */
40#define KS8995_REG_GC5 0x07 /* Global Control 5 */
41#define KS8995_REG_GC6 0x08 /* Global Control 6 */
42#define KS8995_REG_GC7 0x09 /* Global Control 7 */
43#define KS8995_REG_GC8 0x0a /* Global Control 8 */
44#define KS8995_REG_GC9 0x0b /* Global Control 9 */
45
46#define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
47#define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
48
49#define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
50#define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
51#define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */
52#define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */
53#define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */
54#define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */
55#define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */
56#define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */
57
58#define KS8995_REG_MAC0 0x68 /* MAC address 0 */
59#define KS8995_REG_MAC1 0x69 /* MAC address 1 */
60#define KS8995_REG_MAC2 0x6a /* MAC address 2 */
61#define KS8995_REG_MAC3 0x6b /* MAC address 3 */
62#define KS8995_REG_MAC4 0x6c /* MAC address 4 */
63#define KS8995_REG_MAC5 0x6d /* MAC address 5 */
64
65#define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */
66#define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */
67#define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */
68#define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */
69#define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */
70#define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */
71#define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */
72#define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */
73#define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */
74#define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */
75
76#define KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */
77
78#define KS8995_REGS_SIZE 0x80
79#define KSZ8864_REGS_SIZE 0x100
80#define KSZ8795_REGS_SIZE 0x100
81
82#define ID1_CHIPID_M 0xf
83#define ID1_CHIPID_S 4
84#define ID1_REVISION_M 0x7
85#define ID1_REVISION_S 1
86#define ID1_START_SW 1 /* start the switch */
87
88#define FAMILY_KS8995 0x95
89#define FAMILY_KSZ8795 0x87
90#define CHIPID_M 0
91#define KS8995_CHIP_ID 0x00
92#define KSZ8864_CHIP_ID 0x01
93#define KSZ8795_CHIP_ID 0x09
94
95#define KS8995_CMD_WRITE 0x02U
96#define KS8995_CMD_READ 0x03U
97
98#define KS8995_RESET_DELAY 10 /* usec */
99
100enum ks8995_chip_variant {
101 ks8995,
102 ksz8864,
103 ksz8795,
104 max_variant
105};
106
107struct ks8995_chip_params {
108 char *name;
109 int family_id;
110 int chip_id;
111 int regs_size;
112 int addr_width;
113 int addr_shift;
114};
115
116static const struct ks8995_chip_params ks8995_chip[] = {
117 [ks8995] = {
118 .name = "KS8995MA",
119 .family_id = FAMILY_KS8995,
120 .chip_id = KS8995_CHIP_ID,
121 .regs_size = KS8995_REGS_SIZE,
122 .addr_width = 8,
123 .addr_shift = 0,
124 },
125 [ksz8864] = {
126 .name = "KSZ8864RMN",
127 .family_id = FAMILY_KS8995,
128 .chip_id = KSZ8864_CHIP_ID,
129 .regs_size = KSZ8864_REGS_SIZE,
130 .addr_width = 8,
131 .addr_shift = 0,
132 },
133 [ksz8795] = {
134 .name = "KSZ8795CLX",
135 .family_id = FAMILY_KSZ8795,
136 .chip_id = KSZ8795_CHIP_ID,
137 .regs_size = KSZ8795_REGS_SIZE,
138 .addr_width = 12,
139 .addr_shift = 1,
140 },
141};
142
143struct ks8995_pdata {
144 int reset_gpio;
145 enum of_gpio_flags reset_gpio_flags;
146};
147
148struct ks8995_switch {
149 struct spi_device *spi;
150 struct mutex lock;
151 struct ks8995_pdata *pdata;
152 struct bin_attribute regs_attr;
153 const struct ks8995_chip_params *chip;
154 int revision_id;
155};
156
157static const struct spi_device_id ks8995_id[] = {
158 {"ks8995", ks8995},
159 {"ksz8864", ksz8864},
160 {"ksz8795", ksz8795},
161 { }
162};
163MODULE_DEVICE_TABLE(spi, ks8995_id);
164
165static inline u8 get_chip_id(u8 val)
166{
167 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
168}
169
170static inline u8 get_chip_rev(u8 val)
171{
172 return (val >> ID1_REVISION_S) & ID1_REVISION_M;
173}
174
175/* create_spi_cmd - create a chip specific SPI command header
176 * @ks: pointer to switch instance
177 * @cmd: SPI command for switch
178 * @address: register address for command
179 *
180 * Different chip families use different bit pattern to address the switches
181 * registers:
182 *
183 * KS8995: 8bit command + 8bit address
184 * KSZ8795: 3bit command + 12bit address + 1bit TR (?)
185 */
186static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
187 unsigned address)
188{
189 u16 result = cmd;
190
191 /* make room for address (incl. address shift) */
192 result <<= ks->chip->addr_width + ks->chip->addr_shift;
193 /* add address */
194 result |= address << ks->chip->addr_shift;
195 /* SPI protocol needs big endian */
196 return cpu_to_be16(result);
197}
198/* ------------------------------------------------------------------------ */
199static int ks8995_read(struct ks8995_switch *ks, char *buf,
200 unsigned offset, size_t count)
201{
202 __be16 cmd;
203 struct spi_transfer t[2];
204 struct spi_message m;
205 int err;
206
207 cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
208 spi_message_init(&m);
209
210 memset(&t, 0, sizeof(t));
211
212 t[0].tx_buf = &cmd;
213 t[0].len = sizeof(cmd);
214 spi_message_add_tail(&t[0], &m);
215
216 t[1].rx_buf = buf;
217 t[1].len = count;
218 spi_message_add_tail(&t[1], &m);
219
220 mutex_lock(&ks->lock);
221 err = spi_sync(ks->spi, &m);
222 mutex_unlock(&ks->lock);
223
224 return err ? err : count;
225}
226
227static int ks8995_write(struct ks8995_switch *ks, char *buf,
228 unsigned offset, size_t count)
229{
230 __be16 cmd;
231 struct spi_transfer t[2];
232 struct spi_message m;
233 int err;
234
235 cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
236 spi_message_init(&m);
237
238 memset(&t, 0, sizeof(t));
239
240 t[0].tx_buf = &cmd;
241 t[0].len = sizeof(cmd);
242 spi_message_add_tail(&t[0], &m);
243
244 t[1].tx_buf = buf;
245 t[1].len = count;
246 spi_message_add_tail(&t[1], &m);
247
248 mutex_lock(&ks->lock);
249 err = spi_sync(ks->spi, &m);
250 mutex_unlock(&ks->lock);
251
252 return err ? err : count;
253}
254
255static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
256{
257 return ks8995_read(ks, buf, addr, 1) != 1;
258}
259
260static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
261{
262 char buf = val;
263
264 return ks8995_write(ks, &buf, addr, 1) != 1;
265}
266
267/* ------------------------------------------------------------------------ */
268
269static int ks8995_stop(struct ks8995_switch *ks)
270{
271 return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
272}
273
274static int ks8995_start(struct ks8995_switch *ks)
275{
276 return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
277}
278
279static int ks8995_reset(struct ks8995_switch *ks)
280{
281 int err;
282
283 err = ks8995_stop(ks);
284 if (err)
285 return err;
286
287 udelay(KS8995_RESET_DELAY);
288
289 return ks8995_start(ks);
290}
291
292static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
293 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
294{
295 struct device *dev;
296 struct ks8995_switch *ks8995;
297
298 dev = container_of(kobj, struct device, kobj);
299 ks8995 = dev_get_drvdata(dev);
300
301 return ks8995_read(ks8995, buf, off, count);
302}
303
304static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
305 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
306{
307 struct device *dev;
308 struct ks8995_switch *ks8995;
309
310 dev = container_of(kobj, struct device, kobj);
311 ks8995 = dev_get_drvdata(dev);
312
313 return ks8995_write(ks8995, buf, off, count);
314}
315
316/* ks8995_get_revision - get chip revision
317 * @ks: pointer to switch instance
318 *
319 * Verify chip family and id and get chip revision.
320 */
321static int ks8995_get_revision(struct ks8995_switch *ks)
322{
323 int err;
324 u8 id0, id1, ksz8864_id;
325
326 /* read family id */
327 err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
328 if (err) {
329 err = -EIO;
330 goto err_out;
331 }
332
333 /* verify family id */
334 if (id0 != ks->chip->family_id) {
335 dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
336 ks->chip->family_id, id0);
337 err = -ENODEV;
338 goto err_out;
339 }
340
341 switch (ks->chip->family_id) {
342 case FAMILY_KS8995:
343 /* try reading chip id at CHIP ID1 */
344 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
345 if (err) {
346 err = -EIO;
347 goto err_out;
348 }
349
350 /* verify chip id */
351 if ((get_chip_id(id1) == CHIPID_M) &&
352 (get_chip_id(id1) == ks->chip->chip_id)) {
353 /* KS8995MA */
354 ks->revision_id = get_chip_rev(id1);
355 } else if (get_chip_id(id1) != CHIPID_M) {
356 /* KSZ8864RMN */
357 err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
358 if (err) {
359 err = -EIO;
360 goto err_out;
361 }
362
363 if ((ksz8864_id & 0x80) &&
364 (ks->chip->chip_id == KSZ8864_CHIP_ID)) {
365 ks->revision_id = get_chip_rev(id1);
366 }
367
368 } else {
369 dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
370 id1);
371 err = -ENODEV;
372 }
373 break;
374 case FAMILY_KSZ8795:
375 /* try reading chip id at CHIP ID1 */
376 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
377 if (err) {
378 err = -EIO;
379 goto err_out;
380 }
381
382 if (get_chip_id(id1) == ks->chip->chip_id) {
383 ks->revision_id = get_chip_rev(id1);
384 } else {
385 dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
386 id1);
387 err = -ENODEV;
388 }
389 break;
390 default:
391 dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
392 err = -ENODEV;
393 break;
394 }
395err_out:
396 return err;
397}
398
399/* ks8995_parse_dt - setup platform data from devicetree
400 * @ks: pointer to switch instance
401 *
402 * Parses supported DT properties and sets up platform data
403 * accordingly.
404 */
405static void ks8995_parse_dt(struct ks8995_switch *ks)
406{
407 struct device_node *np = ks->spi->dev.of_node;
408 struct ks8995_pdata *pdata = ks->pdata;
409
410 if (!np)
411 return;
412
413 pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0,
414 &pdata->reset_gpio_flags);
415}
416
417static const struct bin_attribute ks8995_registers_attr = {
418 .attr = {
419 .name = "registers",
420 .mode = S_IRUSR | S_IWUSR,
421 },
422 .size = KS8995_REGS_SIZE,
423 .read = ks8995_registers_read,
424 .write = ks8995_registers_write,
425};
426
427/* ------------------------------------------------------------------------ */
428static int ks8995_probe(struct spi_device *spi)
429{
430 struct ks8995_switch *ks;
431 int err;
432 int variant = spi_get_device_id(spi)->driver_data;
433
434 if (variant >= max_variant) {
435 dev_err(&spi->dev, "bad chip variant %d\n", variant);
436 return -ENODEV;
437 }
438
439 ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
440 if (!ks)
441 return -ENOMEM;
442
443 mutex_init(&ks->lock);
444 ks->spi = spi;
445 ks->chip = &ks8995_chip[variant];
446
447 if (ks->spi->dev.of_node) {
448 ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata),
449 GFP_KERNEL);
450 if (!ks->pdata)
451 return -ENOMEM;
452
453 ks->pdata->reset_gpio = -1;
454
455 ks8995_parse_dt(ks);
456 }
457
458 if (!ks->pdata)
459 ks->pdata = spi->dev.platform_data;
460
461 /* de-assert switch reset */
462 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) {
463 unsigned long flags;
464
465 flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ?
466 GPIOF_ACTIVE_LOW : 0);
467
468 err = devm_gpio_request_one(&spi->dev,
469 ks->pdata->reset_gpio,
470 flags, "switch-reset");
471 if (err) {
472 dev_err(&spi->dev,
473 "failed to get reset-gpios: %d\n", err);
474 return -EIO;
475 }
476
477 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0);
478 }
479
480 spi_set_drvdata(spi, ks);
481
482 spi->mode = SPI_MODE_0;
483 spi->bits_per_word = 8;
484 err = spi_setup(spi);
485 if (err) {
486 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
487 return err;
488 }
489
490 err = ks8995_get_revision(ks);
491 if (err)
492 return err;
493
494 ks->regs_attr.size = ks->chip->regs_size;
495 memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
496
497 err = ks8995_reset(ks);
498 if (err)
499 return err;
500
501 err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
502 if (err) {
503 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
504 err);
505 return err;
506 }
507
508 dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
509 ks->chip->name, ks->chip->chip_id, ks->revision_id);
510
511 return 0;
512}
513
514static int ks8995_remove(struct spi_device *spi)
515{
516 struct ks8995_switch *ks = spi_get_drvdata(spi);
517
518 sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);
519
520 /* assert reset */
521 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio))
522 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1);
523
524 return 0;
525}
526
527/* ------------------------------------------------------------------------ */
528static struct spi_driver ks8995_driver = {
529 .driver = {
530 .name = "spi-ks8995",
531 },
532 .probe = ks8995_probe,
533 .remove = ks8995_remove,
534 .id_table = ks8995_id,
535};
536
537module_spi_driver(ks8995_driver);
538
539MODULE_DESCRIPTION(DRV_DESC);
540MODULE_VERSION(DRV_VERSION);
541MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
542MODULE_LICENSE("GPL v2");