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 #include <linux/of_gpio.h> 21 22 #include <linux/spi/spi.h> 23 24 #define DRV_VERSION "0.1.1" 25 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver" 26 27 /* ------------------------------------------------------------------------ */ 28 29 #define KS8995_REG_ID0 0x00 /* Chip ID0 */ 30 #define KS8995_REG_ID1 0x01 /* Chip ID1 */ 31 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 */ 42 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 */ 45 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 */ 54 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 */ 61 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 */ 72 73 #define KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */ 74 75 #define KS8995_REGS_SIZE 0x80 76 #define KSZ8864_REGS_SIZE 0x100 77 #define KSZ8795_REGS_SIZE 0x100 78 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 */ 84 85 #define FAMILY_KS8995 0x95 86 #define FAMILY_KSZ8795 0x87 87 #define CHIPID_M 0 88 #define KS8995_CHIP_ID 0x00 89 #define KSZ8864_CHIP_ID 0x01 90 #define KSZ8795_CHIP_ID 0x09 91 92 #define KS8995_CMD_WRITE 0x02U 93 #define KS8995_CMD_READ 0x03U 94 95 #define KS8995_RESET_DELAY 10 /* usec */ 96 97 enum ks8995_chip_variant { 98 ks8995, 99 ksz8864, 100 ksz8795, 101 max_variant 102 }; 103 104 struct ks8995_chip_params { 105 char *name; 106 int family_id; 107 int chip_id; 108 int regs_size; 109 int addr_width; 110 int addr_shift; 111 }; 112 113 static const struct ks8995_chip_params ks8995_chip[] = { 114 [ks8995] = { 115 .name = "KS8995MA", 116 .family_id = FAMILY_KS8995, 117 .chip_id = KS8995_CHIP_ID, 118 .regs_size = KS8995_REGS_SIZE, 119 .addr_width = 8, 120 .addr_shift = 0, 121 }, 122 [ksz8864] = { 123 .name = "KSZ8864RMN", 124 .family_id = FAMILY_KS8995, 125 .chip_id = KSZ8864_CHIP_ID, 126 .regs_size = KSZ8864_REGS_SIZE, 127 .addr_width = 8, 128 .addr_shift = 0, 129 }, 130 [ksz8795] = { 131 .name = "KSZ8795CLX", 132 .family_id = FAMILY_KSZ8795, 133 .chip_id = KSZ8795_CHIP_ID, 134 .regs_size = KSZ8795_REGS_SIZE, 135 .addr_width = 12, 136 .addr_shift = 1, 137 }, 138 }; 139 140 struct ks8995_pdata { 141 int reset_gpio; 142 enum of_gpio_flags reset_gpio_flags; 143 }; 144 145 struct ks8995_switch { 146 struct spi_device *spi; 147 struct mutex lock; 148 struct ks8995_pdata *pdata; 149 struct bin_attribute regs_attr; 150 const struct ks8995_chip_params *chip; 151 int revision_id; 152 }; 153 154 static const struct spi_device_id ks8995_id[] = { 155 {"ks8995", ks8995}, 156 {"ksz8864", ksz8864}, 157 {"ksz8795", ksz8795}, 158 { } 159 }; 160 MODULE_DEVICE_TABLE(spi, ks8995_id); 161 162 static const struct of_device_id ks8895_spi_of_match[] = { 163 { .compatible = "micrel,ks8995" }, 164 { .compatible = "micrel,ksz8864" }, 165 { .compatible = "micrel,ksz8795" }, 166 { }, 167 }; 168 MODULE_DEVICE_TABLE(of, ks8895_spi_of_match); 169 170 static inline u8 get_chip_id(u8 val) 171 { 172 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M; 173 } 174 175 static inline u8 get_chip_rev(u8 val) 176 { 177 return (val >> ID1_REVISION_S) & ID1_REVISION_M; 178 } 179 180 /* create_spi_cmd - create a chip specific SPI command header 181 * @ks: pointer to switch instance 182 * @cmd: SPI command for switch 183 * @address: register address for command 184 * 185 * Different chip families use different bit pattern to address the switches 186 * registers: 187 * 188 * KS8995: 8bit command + 8bit address 189 * KSZ8795: 3bit command + 12bit address + 1bit TR (?) 190 */ 191 static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd, 192 unsigned address) 193 { 194 u16 result = cmd; 195 196 /* make room for address (incl. address shift) */ 197 result <<= ks->chip->addr_width + ks->chip->addr_shift; 198 /* add address */ 199 result |= address << ks->chip->addr_shift; 200 /* SPI protocol needs big endian */ 201 return cpu_to_be16(result); 202 } 203 /* ------------------------------------------------------------------------ */ 204 static int ks8995_read(struct ks8995_switch *ks, char *buf, 205 unsigned offset, size_t count) 206 { 207 __be16 cmd; 208 struct spi_transfer t[2]; 209 struct spi_message m; 210 int err; 211 212 cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset); 213 spi_message_init(&m); 214 215 memset(&t, 0, sizeof(t)); 216 217 t[0].tx_buf = &cmd; 218 t[0].len = sizeof(cmd); 219 spi_message_add_tail(&t[0], &m); 220 221 t[1].rx_buf = buf; 222 t[1].len = count; 223 spi_message_add_tail(&t[1], &m); 224 225 mutex_lock(&ks->lock); 226 err = spi_sync(ks->spi, &m); 227 mutex_unlock(&ks->lock); 228 229 return err ? err : count; 230 } 231 232 static int ks8995_write(struct ks8995_switch *ks, char *buf, 233 unsigned offset, size_t count) 234 { 235 __be16 cmd; 236 struct spi_transfer t[2]; 237 struct spi_message m; 238 int err; 239 240 cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset); 241 spi_message_init(&m); 242 243 memset(&t, 0, sizeof(t)); 244 245 t[0].tx_buf = &cmd; 246 t[0].len = sizeof(cmd); 247 spi_message_add_tail(&t[0], &m); 248 249 t[1].tx_buf = buf; 250 t[1].len = count; 251 spi_message_add_tail(&t[1], &m); 252 253 mutex_lock(&ks->lock); 254 err = spi_sync(ks->spi, &m); 255 mutex_unlock(&ks->lock); 256 257 return err ? err : count; 258 } 259 260 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) 261 { 262 return ks8995_read(ks, buf, addr, 1) != 1; 263 } 264 265 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val) 266 { 267 char buf = val; 268 269 return ks8995_write(ks, &buf, addr, 1) != 1; 270 } 271 272 /* ------------------------------------------------------------------------ */ 273 274 static int ks8995_stop(struct ks8995_switch *ks) 275 { 276 return ks8995_write_reg(ks, KS8995_REG_ID1, 0); 277 } 278 279 static int ks8995_start(struct ks8995_switch *ks) 280 { 281 return ks8995_write_reg(ks, KS8995_REG_ID1, 1); 282 } 283 284 static int ks8995_reset(struct ks8995_switch *ks) 285 { 286 int err; 287 288 err = ks8995_stop(ks); 289 if (err) 290 return err; 291 292 udelay(KS8995_RESET_DELAY); 293 294 return ks8995_start(ks); 295 } 296 297 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj, 298 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 299 { 300 struct device *dev; 301 struct ks8995_switch *ks8995; 302 303 dev = kobj_to_dev(kobj); 304 ks8995 = dev_get_drvdata(dev); 305 306 return ks8995_read(ks8995, buf, off, count); 307 } 308 309 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj, 310 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 311 { 312 struct device *dev; 313 struct ks8995_switch *ks8995; 314 315 dev = kobj_to_dev(kobj); 316 ks8995 = dev_get_drvdata(dev); 317 318 return ks8995_write(ks8995, buf, off, count); 319 } 320 321 /* ks8995_get_revision - get chip revision 322 * @ks: pointer to switch instance 323 * 324 * Verify chip family and id and get chip revision. 325 */ 326 static int ks8995_get_revision(struct ks8995_switch *ks) 327 { 328 int err; 329 u8 id0, id1, ksz8864_id; 330 331 /* read family id */ 332 err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0); 333 if (err) { 334 err = -EIO; 335 goto err_out; 336 } 337 338 /* verify family id */ 339 if (id0 != ks->chip->family_id) { 340 dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n", 341 ks->chip->family_id, id0); 342 err = -ENODEV; 343 goto err_out; 344 } 345 346 switch (ks->chip->family_id) { 347 case FAMILY_KS8995: 348 /* try reading chip id at CHIP ID1 */ 349 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1); 350 if (err) { 351 err = -EIO; 352 goto err_out; 353 } 354 355 /* verify chip id */ 356 if ((get_chip_id(id1) == CHIPID_M) && 357 (get_chip_id(id1) == ks->chip->chip_id)) { 358 /* KS8995MA */ 359 ks->revision_id = get_chip_rev(id1); 360 } else if (get_chip_id(id1) != CHIPID_M) { 361 /* KSZ8864RMN */ 362 err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id); 363 if (err) { 364 err = -EIO; 365 goto err_out; 366 } 367 368 if ((ksz8864_id & 0x80) && 369 (ks->chip->chip_id == KSZ8864_CHIP_ID)) { 370 ks->revision_id = get_chip_rev(id1); 371 } 372 373 } else { 374 dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n", 375 id1); 376 err = -ENODEV; 377 } 378 break; 379 case FAMILY_KSZ8795: 380 /* try reading chip id at CHIP ID1 */ 381 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1); 382 if (err) { 383 err = -EIO; 384 goto err_out; 385 } 386 387 if (get_chip_id(id1) == ks->chip->chip_id) { 388 ks->revision_id = get_chip_rev(id1); 389 } else { 390 dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n", 391 id1); 392 err = -ENODEV; 393 } 394 break; 395 default: 396 dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0); 397 err = -ENODEV; 398 break; 399 } 400 err_out: 401 return err; 402 } 403 404 /* ks8995_parse_dt - setup platform data from devicetree 405 * @ks: pointer to switch instance 406 * 407 * Parses supported DT properties and sets up platform data 408 * accordingly. 409 */ 410 static void ks8995_parse_dt(struct ks8995_switch *ks) 411 { 412 struct device_node *np = ks->spi->dev.of_node; 413 struct ks8995_pdata *pdata = ks->pdata; 414 415 if (!np) 416 return; 417 418 pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0, 419 &pdata->reset_gpio_flags); 420 } 421 422 static const struct bin_attribute ks8995_registers_attr = { 423 .attr = { 424 .name = "registers", 425 .mode = 0600, 426 }, 427 .size = KS8995_REGS_SIZE, 428 .read = ks8995_registers_read, 429 .write = ks8995_registers_write, 430 }; 431 432 /* ------------------------------------------------------------------------ */ 433 static int ks8995_probe(struct spi_device *spi) 434 { 435 struct ks8995_switch *ks; 436 int err; 437 int variant = spi_get_device_id(spi)->driver_data; 438 439 if (variant >= max_variant) { 440 dev_err(&spi->dev, "bad chip variant %d\n", variant); 441 return -ENODEV; 442 } 443 444 ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL); 445 if (!ks) 446 return -ENOMEM; 447 448 mutex_init(&ks->lock); 449 ks->spi = spi; 450 ks->chip = &ks8995_chip[variant]; 451 452 if (ks->spi->dev.of_node) { 453 ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata), 454 GFP_KERNEL); 455 if (!ks->pdata) 456 return -ENOMEM; 457 458 ks->pdata->reset_gpio = -1; 459 460 ks8995_parse_dt(ks); 461 } 462 463 if (!ks->pdata) 464 ks->pdata = spi->dev.platform_data; 465 466 /* de-assert switch reset */ 467 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) { 468 unsigned long flags; 469 470 flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ? 471 GPIOF_ACTIVE_LOW : 0); 472 473 err = devm_gpio_request_one(&spi->dev, 474 ks->pdata->reset_gpio, 475 flags, "switch-reset"); 476 if (err) { 477 dev_err(&spi->dev, 478 "failed to get reset-gpios: %d\n", err); 479 return -EIO; 480 } 481 482 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0); 483 } 484 485 spi_set_drvdata(spi, ks); 486 487 spi->mode = SPI_MODE_0; 488 spi->bits_per_word = 8; 489 err = spi_setup(spi); 490 if (err) { 491 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err); 492 return err; 493 } 494 495 err = ks8995_get_revision(ks); 496 if (err) 497 return err; 498 499 memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr)); 500 ks->regs_attr.size = ks->chip->regs_size; 501 502 err = ks8995_reset(ks); 503 if (err) 504 return err; 505 506 sysfs_attr_init(&ks->regs_attr.attr); 507 err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr); 508 if (err) { 509 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n", 510 err); 511 return err; 512 } 513 514 dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n", 515 ks->chip->name, ks->chip->chip_id, ks->revision_id); 516 517 return 0; 518 } 519 520 static void ks8995_remove(struct spi_device *spi) 521 { 522 struct ks8995_switch *ks = spi_get_drvdata(spi); 523 524 sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr); 525 526 /* assert reset */ 527 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) 528 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1); 529 } 530 531 /* ------------------------------------------------------------------------ */ 532 static struct spi_driver ks8995_driver = { 533 .driver = { 534 .name = "spi-ks8995", 535 .of_match_table = of_match_ptr(ks8895_spi_of_match), 536 }, 537 .probe = ks8995_probe, 538 .remove = ks8995_remove, 539 .id_table = ks8995_id, 540 }; 541 542 module_spi_driver(ks8995_driver); 543 544 MODULE_DESCRIPTION(DRV_DESC); 545 MODULE_VERSION(DRV_VERSION); 546 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); 547 MODULE_LICENSE("GPL v2"); 548