507 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches4 *5 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>6 *7 * This file was based on: drivers/spi/at25.c8 * Copyright (C) 2006 David Brownell9 */10 11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt12 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 0x8075#define KSZ8864_REGS_SIZE 0x10076#define KSZ8795_REGS_SIZE 0x10077 78#define ID1_CHIPID_M 0xf79#define ID1_CHIPID_S 480#define ID1_REVISION_M 0x781#define ID1_REVISION_S 182#define ID1_START_SW 1 /* start the switch */83 84#define FAMILY_KS8995 0x9585#define FAMILY_KSZ8795 0x8786#define CHIPID_M 087#define KS8995_CHIP_ID 0x0088#define KSZ8864_CHIP_ID 0x0189#define KSZ8795_CHIP_ID 0x0990 91#define KS8995_CMD_WRITE 0x02U92#define KS8995_CMD_READ 0x03U93 94#define KS8995_RESET_DELAY 10 /* usec */95 96enum ks8995_chip_variant {97 ks8995,98 ksz8864,99 ksz8795,100 max_variant101};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 header175 * @ks: pointer to switch instance176 * @cmd: SPI command for switch177 * @address: register address for command178 *179 * Different chip families use different bit pattern to address the switches180 * registers:181 *182 * KS8995: 8bit command + 8bit address183 * 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 revision316 * @ks: pointer to switch instance317 *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");507