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, 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 } 225 226 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, 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 } 253 254 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) 255 { 256 return ks8995_read(ks, buf, addr, 1) != 1; 257 } 258 259 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, addr, 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, 0); 271 } 272 273 static int ks8995_start(struct ks8995_switch *ks) 274 { 275 return ks8995_write_reg(ks, KS8995_REG_ID1, 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(ks8995, buf, 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(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 */ 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, &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 } 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(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 } 479 480 static void ks8995_remove(struct spi_device *spi) 481 { 482 struct ks8995_switch *ks = spi_get_drvdata(spi); 483 484 sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr); 485 486 /* assert reset */ 487 gpiod_set_value_cansleep(ks->reset_gpio, 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