1 // SPDX-License-Identifier: GPL-2.0
3 * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
5 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
7 * This file was based on: drivers/spi/at25.c
8 * Copyright (C) 2006 David Brownell
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
20 #include <linux/of_gpio.h>
22 #include <linux/spi/spi.h>
24 #define DRV_VERSION "0.1.1"
25 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver"
27 /* ------------------------------------------------------------------------ */
29 #define KS8995_REG_ID0 0x00 /* Chip ID0 */
30 #define KS8995_REG_ID1 0x01 /* Chip ID1 */
32 #define KS8995_REG_GC0 0x02 /* Global Control 0 */
33 #define KS8995_REG_GC1 0x03 /* Global Control 1 */
34 #define KS8995_REG_GC2 0x04 /* Global Control 2 */
35 #define KS8995_REG_GC3 0x05 /* Global Control 3 */
36 #define KS8995_REG_GC4 0x06 /* Global Control 4 */
37 #define KS8995_REG_GC5 0x07 /* Global Control 5 */
38 #define KS8995_REG_GC6 0x08 /* Global Control 6 */
39 #define KS8995_REG_GC7 0x09 /* Global Control 7 */
40 #define KS8995_REG_GC8 0x0a /* Global Control 8 */
41 #define KS8995_REG_GC9 0x0b /* Global Control 9 */
43 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */
44 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */
46 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */
47 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */
48 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */
49 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */
50 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */
51 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */
52 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */
53 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */
55 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */
56 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */
57 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */
58 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */
59 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */
60 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */
62 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */
63 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */
64 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */
65 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */
66 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */
67 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */
68 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */
69 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */
70 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */
71 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */
73 #define KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */
75 #define KS8995_REGS_SIZE 0x80
76 #define KSZ8864_REGS_SIZE 0x100
77 #define KSZ8795_REGS_SIZE 0x100
79 #define ID1_CHIPID_M 0xf
80 #define ID1_CHIPID_S 4
81 #define ID1_REVISION_M 0x7
82 #define ID1_REVISION_S 1
83 #define ID1_START_SW 1 /* start the switch */
85 #define FAMILY_KS8995 0x95
86 #define FAMILY_KSZ8795 0x87
88 #define KS8995_CHIP_ID 0x00
89 #define KSZ8864_CHIP_ID 0x01
90 #define KSZ8795_CHIP_ID 0x09
92 #define KS8995_CMD_WRITE 0x02U
93 #define KS8995_CMD_READ 0x03U
95 #define KS8995_RESET_DELAY 10 /* usec */
97 enum ks8995_chip_variant {
104 struct ks8995_chip_params {
113 static const struct ks8995_chip_params ks8995_chip[] = {
116 .family_id = FAMILY_KS8995,
117 .chip_id = KS8995_CHIP_ID,
118 .regs_size = KS8995_REGS_SIZE,
123 .name = "KSZ8864RMN",
124 .family_id = FAMILY_KS8995,
125 .chip_id = KSZ8864_CHIP_ID,
126 .regs_size = KSZ8864_REGS_SIZE,
131 .name = "KSZ8795CLX",
132 .family_id = FAMILY_KSZ8795,
133 .chip_id = KSZ8795_CHIP_ID,
134 .regs_size = KSZ8795_REGS_SIZE,
140 struct ks8995_pdata {
142 enum of_gpio_flags reset_gpio_flags;
145 struct ks8995_switch {
146 struct spi_device *spi;
148 struct ks8995_pdata *pdata;
149 struct bin_attribute regs_attr;
150 const struct ks8995_chip_params *chip;
154 static const struct spi_device_id ks8995_id[] = {
156 {"ksz8864", ksz8864},
157 {"ksz8795", ksz8795},
160 MODULE_DEVICE_TABLE(spi, ks8995_id);
162 static inline u8 get_chip_id(u8 val)
164 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
167 static inline u8 get_chip_rev(u8 val)
169 return (val >> ID1_REVISION_S) & ID1_REVISION_M;
172 /* create_spi_cmd - create a chip specific SPI command header
173 * @ks: pointer to switch instance
174 * @cmd: SPI command for switch
175 * @address: register address for command
177 * Different chip families use different bit pattern to address the switches
180 * KS8995: 8bit command + 8bit address
181 * KSZ8795: 3bit command + 12bit address + 1bit TR (?)
183 static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
188 /* make room for address (incl. address shift) */
189 result <<= ks->chip->addr_width + ks->chip->addr_shift;
191 result |= address << ks->chip->addr_shift;
192 /* SPI protocol needs big endian */
193 return cpu_to_be16(result);
195 /* ------------------------------------------------------------------------ */
196 static int ks8995_read(struct ks8995_switch *ks, char *buf,
197 unsigned offset, size_t count)
200 struct spi_transfer t[2];
201 struct spi_message m;
204 cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
205 spi_message_init(&m);
207 memset(&t, 0, sizeof(t));
210 t[0].len = sizeof(cmd);
211 spi_message_add_tail(&t[0], &m);
215 spi_message_add_tail(&t[1], &m);
217 mutex_lock(&ks->lock);
218 err = spi_sync(ks->spi, &m);
219 mutex_unlock(&ks->lock);
221 return err ? err : count;
224 static int ks8995_write(struct ks8995_switch *ks, char *buf,
225 unsigned offset, size_t count)
228 struct spi_transfer t[2];
229 struct spi_message m;
232 cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
233 spi_message_init(&m);
235 memset(&t, 0, sizeof(t));
238 t[0].len = sizeof(cmd);
239 spi_message_add_tail(&t[0], &m);
243 spi_message_add_tail(&t[1], &m);
245 mutex_lock(&ks->lock);
246 err = spi_sync(ks->spi, &m);
247 mutex_unlock(&ks->lock);
249 return err ? err : count;
252 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
254 return ks8995_read(ks, buf, addr, 1) != 1;
257 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
261 return ks8995_write(ks, &buf, addr, 1) != 1;
264 /* ------------------------------------------------------------------------ */
266 static int ks8995_stop(struct ks8995_switch *ks)
268 return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
271 static int ks8995_start(struct ks8995_switch *ks)
273 return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
276 static int ks8995_reset(struct ks8995_switch *ks)
280 err = ks8995_stop(ks);
284 udelay(KS8995_RESET_DELAY);
286 return ks8995_start(ks);
289 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
290 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
293 struct ks8995_switch *ks8995;
295 dev = container_of(kobj, struct device, kobj);
296 ks8995 = dev_get_drvdata(dev);
298 return ks8995_read(ks8995, buf, off, count);
301 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
302 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
305 struct ks8995_switch *ks8995;
307 dev = container_of(kobj, struct device, kobj);
308 ks8995 = dev_get_drvdata(dev);
310 return ks8995_write(ks8995, buf, off, count);
313 /* ks8995_get_revision - get chip revision
314 * @ks: pointer to switch instance
316 * Verify chip family and id and get chip revision.
318 static int ks8995_get_revision(struct ks8995_switch *ks)
321 u8 id0, id1, ksz8864_id;
324 err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
330 /* verify family id */
331 if (id0 != ks->chip->family_id) {
332 dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
333 ks->chip->family_id, id0);
338 switch (ks->chip->family_id) {
340 /* try reading chip id at CHIP ID1 */
341 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
348 if ((get_chip_id(id1) == CHIPID_M) &&
349 (get_chip_id(id1) == ks->chip->chip_id)) {
351 ks->revision_id = get_chip_rev(id1);
352 } else if (get_chip_id(id1) != CHIPID_M) {
354 err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
360 if ((ksz8864_id & 0x80) &&
361 (ks->chip->chip_id == KSZ8864_CHIP_ID)) {
362 ks->revision_id = get_chip_rev(id1);
366 dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
372 /* try reading chip id at CHIP ID1 */
373 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
379 if (get_chip_id(id1) == ks->chip->chip_id) {
380 ks->revision_id = get_chip_rev(id1);
382 dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
388 dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
396 /* ks8995_parse_dt - setup platform data from devicetree
397 * @ks: pointer to switch instance
399 * Parses supported DT properties and sets up platform data
402 static void ks8995_parse_dt(struct ks8995_switch *ks)
404 struct device_node *np = ks->spi->dev.of_node;
405 struct ks8995_pdata *pdata = ks->pdata;
410 pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0,
411 &pdata->reset_gpio_flags);
414 static const struct bin_attribute ks8995_registers_attr = {
419 .size = KS8995_REGS_SIZE,
420 .read = ks8995_registers_read,
421 .write = ks8995_registers_write,
424 /* ------------------------------------------------------------------------ */
425 static int ks8995_probe(struct spi_device *spi)
427 struct ks8995_switch *ks;
429 int variant = spi_get_device_id(spi)->driver_data;
431 if (variant >= max_variant) {
432 dev_err(&spi->dev, "bad chip variant %d\n", variant);
436 ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
440 mutex_init(&ks->lock);
442 ks->chip = &ks8995_chip[variant];
444 if (ks->spi->dev.of_node) {
445 ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata),
450 ks->pdata->reset_gpio = -1;
456 ks->pdata = spi->dev.platform_data;
458 /* de-assert switch reset */
459 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) {
462 flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ?
463 GPIOF_ACTIVE_LOW : 0);
465 err = devm_gpio_request_one(&spi->dev,
466 ks->pdata->reset_gpio,
467 flags, "switch-reset");
470 "failed to get reset-gpios: %d\n", err);
474 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0);
477 spi_set_drvdata(spi, ks);
479 spi->mode = SPI_MODE_0;
480 spi->bits_per_word = 8;
481 err = spi_setup(spi);
483 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
487 err = ks8995_get_revision(ks);
491 memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
492 ks->regs_attr.size = ks->chip->regs_size;
494 err = ks8995_reset(ks);
498 sysfs_attr_init(&ks->regs_attr.attr);
499 err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
501 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
506 dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
507 ks->chip->name, ks->chip->chip_id, ks->revision_id);
512 static int ks8995_remove(struct spi_device *spi)
514 struct ks8995_switch *ks = spi_get_drvdata(spi);
516 sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);
519 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio))
520 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1);
525 /* ------------------------------------------------------------------------ */
526 static struct spi_driver ks8995_driver = {
528 .name = "spi-ks8995",
530 .probe = ks8995_probe,
531 .remove = ks8995_remove,
532 .id_table = ks8995_id,
535 module_spi_driver(ks8995_driver);
537 MODULE_DESCRIPTION(DRV_DESC);
538 MODULE_VERSION(DRV_VERSION);
539 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
540 MODULE_LICENSE("GPL v2");