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 | |
96 | enum ks8995_chip_variant { |
97 | ks8995, |
98 | ksz8864, |
99 | ksz8795, |
100 | max_variant |
101 | }; |
102 | |
103 | struct 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 | |
112 | static 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 | |
139 | struct 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 | |
148 | static const struct spi_device_id ks8995_id[] = { |
149 | {"ks8995" , ks8995}, |
150 | {"ksz8864" , ksz8864}, |
151 | {"ksz8795" , ksz8795}, |
152 | { } |
153 | }; |
154 | MODULE_DEVICE_TABLE(spi, ks8995_id); |
155 | |
156 | static const struct of_device_id ks8895_spi_of_match[] = { |
157 | { .compatible = "micrel,ks8995" }, |
158 | { .compatible = "micrel,ksz8864" }, |
159 | { .compatible = "micrel,ksz8795" }, |
160 | { }, |
161 | }; |
162 | MODULE_DEVICE_TABLE(of, ks8895_spi_of_match); |
163 | |
164 | static inline u8 get_chip_id(u8 val) |
165 | { |
166 | return (val >> ID1_CHIPID_S) & ID1_CHIPID_M; |
167 | } |
168 | |
169 | static 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 | */ |
185 | static 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 | /* ------------------------------------------------------------------------ */ |
198 | static 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, address: offset); |
207 | spi_message_init(m: &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: &t[0], m: &m); |
214 | |
215 | t[1].rx_buf = buf; |
216 | t[1].len = count; |
217 | spi_message_add_tail(t: &t[1], m: &m); |
218 | |
219 | mutex_lock(&ks->lock); |
220 | err = spi_sync(spi: ks->spi, message: &m); |
221 | mutex_unlock(lock: &ks->lock); |
222 | |
223 | return err ? err : count; |
224 | } |
225 | |
226 | static 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, address: offset); |
235 | spi_message_init(m: &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: &t[0], m: &m); |
242 | |
243 | t[1].tx_buf = buf; |
244 | t[1].len = count; |
245 | spi_message_add_tail(t: &t[1], m: &m); |
246 | |
247 | mutex_lock(&ks->lock); |
248 | err = spi_sync(spi: ks->spi, message: &m); |
249 | mutex_unlock(lock: &ks->lock); |
250 | |
251 | return err ? err : count; |
252 | } |
253 | |
254 | static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) |
255 | { |
256 | return ks8995_read(ks, buf, offset: addr, count: 1) != 1; |
257 | } |
258 | |
259 | static 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: &buf, offset: addr, count: 1) != 1; |
264 | } |
265 | |
266 | /* ------------------------------------------------------------------------ */ |
267 | |
268 | static int ks8995_stop(struct ks8995_switch *ks) |
269 | { |
270 | return ks8995_write_reg(ks, KS8995_REG_ID1, val: 0); |
271 | } |
272 | |
273 | static int ks8995_start(struct ks8995_switch *ks) |
274 | { |
275 | return ks8995_write_reg(ks, KS8995_REG_ID1, val: 1); |
276 | } |
277 | |
278 | static 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 | |
291 | static 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(ks: ks8995, buf, offset: off, count); |
301 | } |
302 | |
303 | static 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(ks: ks8995, buf, offset: 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 | */ |
320 | static 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, buf: &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, buf: &id1); |
344 | if (err) { |
345 | err = -EIO; |
346 | goto err_out; |
347 | } |
348 | |
349 | /* verify chip id */ |
350 | if ((get_chip_id(val: id1) == CHIPID_M) && |
351 | (get_chip_id(val: id1) == ks->chip->chip_id)) { |
352 | /* KS8995MA */ |
353 | ks->revision_id = get_chip_rev(val: id1); |
354 | } else if (get_chip_id(val: id1) != CHIPID_M) { |
355 | /* KSZ8864RMN */ |
356 | err = ks8995_read_reg(ks, KS8995_REG_ID1, buf: &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(val: 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, buf: &id1); |
376 | if (err) { |
377 | err = -EIO; |
378 | goto err_out; |
379 | } |
380 | |
381 | if (get_chip_id(val: id1) == ks->chip->chip_id) { |
382 | ks->revision_id = get_chip_rev(val: 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 | } |
394 | err_out: |
395 | return err; |
396 | } |
397 | |
398 | static 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 | /* ------------------------------------------------------------------------ */ |
409 | static int ks8995_probe(struct spi_device *spi) |
410 | { |
411 | struct ks8995_switch *ks; |
412 | int err; |
413 | int variant = spi_get_device_id(sdev: 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(dev: &spi->dev, size: 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(dev: &spi->dev, con_id: "reset" , |
429 | flags: GPIOD_OUT_HIGH); |
430 | err = PTR_ERR_OR_ZERO(ptr: 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(desc: ks->reset_gpio, name: "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(desc: ks->reset_gpio, value: 0); |
444 | |
445 | spi_set_drvdata(spi, data: 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(kobj: &spi->dev.kobj, attr: &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 | |
480 | static void ks8995_remove(struct spi_device *spi) |
481 | { |
482 | struct ks8995_switch *ks = spi_get_drvdata(spi); |
483 | |
484 | sysfs_remove_bin_file(kobj: &spi->dev.kobj, attr: &ks->regs_attr); |
485 | |
486 | /* assert reset */ |
487 | gpiod_set_value_cansleep(desc: ks->reset_gpio, value: 1); |
488 | } |
489 | |
490 | /* ------------------------------------------------------------------------ */ |
491 | static 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 | |
501 | module_spi_driver(ks8995_driver); |
502 | |
503 | MODULE_DESCRIPTION(DRV_DESC); |
504 | MODULE_VERSION(DRV_VERSION); |
505 | MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>" ); |
506 | MODULE_LICENSE("GPL v2" ); |
507 | |