1 /* 2 * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches 3 * 4 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org> 5 * 6 * This file was based on: drivers/spi/at25.c 7 * Copyright (C) 2006 David Brownell 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License version 2 as published 11 * by the Free Software Foundation. 12 */ 13 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/delay.h> 20 #include <linux/device.h> 21 #include <linux/of.h> 22 #include <linux/gpio.h> 23 #include <linux/of_gpio.h> 24 25 #include <linux/spi/spi.h> 26 27 #define DRV_VERSION "0.1.1" 28 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver" 29 30 /* ------------------------------------------------------------------------ */ 31 32 #define KS8995_REG_ID0 0x00 /* Chip ID0 */ 33 #define KS8995_REG_ID1 0x01 /* Chip ID1 */ 34 35 #define KS8995_REG_GC0 0x02 /* Global Control 0 */ 36 #define KS8995_REG_GC1 0x03 /* Global Control 1 */ 37 #define KS8995_REG_GC2 0x04 /* Global Control 2 */ 38 #define KS8995_REG_GC3 0x05 /* Global Control 3 */ 39 #define KS8995_REG_GC4 0x06 /* Global Control 4 */ 40 #define KS8995_REG_GC5 0x07 /* Global Control 5 */ 41 #define KS8995_REG_GC6 0x08 /* Global Control 6 */ 42 #define KS8995_REG_GC7 0x09 /* Global Control 7 */ 43 #define KS8995_REG_GC8 0x0a /* Global Control 8 */ 44 #define KS8995_REG_GC9 0x0b /* Global Control 9 */ 45 46 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */ 47 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */ 48 49 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */ 50 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */ 51 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */ 52 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */ 53 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */ 54 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */ 55 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */ 56 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */ 57 58 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */ 59 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */ 60 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */ 61 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */ 62 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */ 63 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */ 64 65 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */ 66 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */ 67 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */ 68 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */ 69 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */ 70 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */ 71 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */ 72 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */ 73 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */ 74 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */ 75 76 #define KSZ8864_REG_ID1 0xfe /* Chip ID in bit 7 */ 77 78 #define KS8995_REGS_SIZE 0x80 79 #define KSZ8864_REGS_SIZE 0x100 80 81 #define ID1_CHIPID_M 0xf 82 #define ID1_CHIPID_S 4 83 #define ID1_REVISION_M 0x7 84 #define ID1_REVISION_S 1 85 #define ID1_START_SW 1 /* start the switch */ 86 87 #define FAMILY_KS8995 0x95 88 #define CHIPID_M 0 89 #define KS8995_CHIP_ID 0x00 90 #define KSZ8864_CHIP_ID 0x01 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 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 }; 130 131 struct ks8995_pdata { 132 int reset_gpio; 133 enum of_gpio_flags reset_gpio_flags; 134 }; 135 136 struct ks8995_switch { 137 struct spi_device *spi; 138 struct mutex lock; 139 struct ks8995_pdata *pdata; 140 struct bin_attribute regs_attr; 141 const struct ks8995_chip_params *chip; 142 int revision_id; 143 }; 144 145 static const struct spi_device_id ks8995_id[] = { 146 {"ks8995", ks8995}, 147 {"ksz8864", ksz8864}, 148 { } 149 }; 150 MODULE_DEVICE_TABLE(spi, ks8995_id); 151 152 static inline u8 get_chip_id(u8 val) 153 { 154 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M; 155 } 156 157 static inline u8 get_chip_rev(u8 val) 158 { 159 return (val >> ID1_REVISION_S) & ID1_REVISION_M; 160 } 161 162 /* create_spi_cmd - create a chip specific SPI command header 163 * @ks: pointer to switch instance 164 * @cmd: SPI command for switch 165 * @address: register address for command 166 * 167 * Different chip families use different bit pattern to address the switches 168 * registers: 169 * 170 * KS8995: 8bit command + 8bit address 171 * KSZ8795: 3bit command + 12bit address + 1bit TR (?) 172 */ 173 static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd, 174 unsigned address) 175 { 176 u16 result = cmd; 177 178 /* make room for address (incl. address shift) */ 179 result <<= ks->chip->addr_width + ks->chip->addr_shift; 180 /* add address */ 181 result |= address << ks->chip->addr_shift; 182 /* SPI protocol needs big endian */ 183 return cpu_to_be16(result); 184 } 185 /* ------------------------------------------------------------------------ */ 186 static int ks8995_read(struct ks8995_switch *ks, char *buf, 187 unsigned offset, size_t count) 188 { 189 __be16 cmd; 190 struct spi_transfer t[2]; 191 struct spi_message m; 192 int err; 193 194 cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset); 195 spi_message_init(&m); 196 197 memset(&t, 0, sizeof(t)); 198 199 t[0].tx_buf = &cmd; 200 t[0].len = sizeof(cmd); 201 spi_message_add_tail(&t[0], &m); 202 203 t[1].rx_buf = buf; 204 t[1].len = count; 205 spi_message_add_tail(&t[1], &m); 206 207 mutex_lock(&ks->lock); 208 err = spi_sync(ks->spi, &m); 209 mutex_unlock(&ks->lock); 210 211 return err ? err : count; 212 } 213 214 static int ks8995_write(struct ks8995_switch *ks, char *buf, 215 unsigned offset, size_t count) 216 { 217 __be16 cmd; 218 struct spi_transfer t[2]; 219 struct spi_message m; 220 int err; 221 222 cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset); 223 spi_message_init(&m); 224 225 memset(&t, 0, sizeof(t)); 226 227 t[0].tx_buf = &cmd; 228 t[0].len = sizeof(cmd); 229 spi_message_add_tail(&t[0], &m); 230 231 t[1].tx_buf = buf; 232 t[1].len = count; 233 spi_message_add_tail(&t[1], &m); 234 235 mutex_lock(&ks->lock); 236 err = spi_sync(ks->spi, &m); 237 mutex_unlock(&ks->lock); 238 239 return err ? err : count; 240 } 241 242 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) 243 { 244 return ks8995_read(ks, buf, addr, 1) != 1; 245 } 246 247 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val) 248 { 249 char buf = val; 250 251 return ks8995_write(ks, &buf, addr, 1) != 1; 252 } 253 254 /* ------------------------------------------------------------------------ */ 255 256 static int ks8995_stop(struct ks8995_switch *ks) 257 { 258 return ks8995_write_reg(ks, KS8995_REG_ID1, 0); 259 } 260 261 static int ks8995_start(struct ks8995_switch *ks) 262 { 263 return ks8995_write_reg(ks, KS8995_REG_ID1, 1); 264 } 265 266 static int ks8995_reset(struct ks8995_switch *ks) 267 { 268 int err; 269 270 err = ks8995_stop(ks); 271 if (err) 272 return err; 273 274 udelay(KS8995_RESET_DELAY); 275 276 return ks8995_start(ks); 277 } 278 279 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj, 280 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 281 { 282 struct device *dev; 283 struct ks8995_switch *ks8995; 284 285 dev = container_of(kobj, struct device, kobj); 286 ks8995 = dev_get_drvdata(dev); 287 288 return ks8995_read(ks8995, buf, off, count); 289 } 290 291 static ssize_t ks8995_registers_write(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 = container_of(kobj, struct device, kobj); 298 ks8995 = dev_get_drvdata(dev); 299 300 return ks8995_write(ks8995, buf, off, count); 301 } 302 303 /* ks8995_get_revision - get chip revision 304 * @ks: pointer to switch instance 305 * 306 * Verify chip family and id and get chip revision. 307 */ 308 static int ks8995_get_revision(struct ks8995_switch *ks) 309 { 310 int err; 311 u8 id0, id1, ksz8864_id; 312 313 /* read family id */ 314 err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0); 315 if (err) { 316 err = -EIO; 317 goto err_out; 318 } 319 320 /* verify family id */ 321 if (id0 != ks->chip->family_id) { 322 dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n", 323 ks->chip->family_id, id0); 324 err = -ENODEV; 325 goto err_out; 326 } 327 328 switch (ks->chip->family_id) { 329 case FAMILY_KS8995: 330 /* try reading chip id at CHIP ID1 */ 331 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1); 332 if (err) { 333 err = -EIO; 334 goto err_out; 335 } 336 337 /* verify chip id */ 338 if ((get_chip_id(id1) == CHIPID_M) && 339 (get_chip_id(id1) == ks->chip->chip_id)) { 340 /* KS8995MA */ 341 ks->revision_id = get_chip_rev(id1); 342 } else if (get_chip_id(id1) != CHIPID_M) { 343 /* KSZ8864RMN */ 344 err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id); 345 if (err) { 346 err = -EIO; 347 goto err_out; 348 } 349 350 if ((ksz8864_id & 0x80) && 351 (ks->chip->chip_id == KSZ8864_CHIP_ID)) { 352 ks->revision_id = get_chip_rev(id1); 353 } 354 355 } else { 356 dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n", 357 id1); 358 err = -ENODEV; 359 } 360 break; 361 default: 362 dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0); 363 err = -ENODEV; 364 break; 365 } 366 err_out: 367 return err; 368 } 369 370 /* ks8995_parse_dt - setup platform data from devicetree 371 * @ks: pointer to switch instance 372 * 373 * Parses supported DT properties and sets up platform data 374 * accordingly. 375 */ 376 static void ks8995_parse_dt(struct ks8995_switch *ks) 377 { 378 struct device_node *np = ks->spi->dev.of_node; 379 struct ks8995_pdata *pdata = ks->pdata; 380 381 if (!np) 382 return; 383 384 pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0, 385 &pdata->reset_gpio_flags); 386 } 387 388 static const struct bin_attribute ks8995_registers_attr = { 389 .attr = { 390 .name = "registers", 391 .mode = S_IRUSR | S_IWUSR, 392 }, 393 .size = KS8995_REGS_SIZE, 394 .read = ks8995_registers_read, 395 .write = ks8995_registers_write, 396 }; 397 398 /* ------------------------------------------------------------------------ */ 399 static int ks8995_probe(struct spi_device *spi) 400 { 401 struct ks8995_switch *ks; 402 int err; 403 int variant = spi_get_device_id(spi)->driver_data; 404 405 if (variant >= max_variant) { 406 dev_err(&spi->dev, "bad chip variant %d\n", variant); 407 return -ENODEV; 408 } 409 410 ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL); 411 if (!ks) 412 return -ENOMEM; 413 414 mutex_init(&ks->lock); 415 ks->spi = spi_dev_get(spi); 416 ks->chip = &ks8995_chip[variant]; 417 418 if (ks->spi->dev.of_node) { 419 ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata), 420 GFP_KERNEL); 421 if (!ks->pdata) 422 return -ENOMEM; 423 424 ks->pdata->reset_gpio = -1; 425 426 ks8995_parse_dt(ks); 427 } 428 429 if (!ks->pdata) 430 ks->pdata = spi->dev.platform_data; 431 432 /* de-assert switch reset */ 433 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) { 434 unsigned long flags; 435 436 flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ? 437 GPIOF_ACTIVE_LOW : 0); 438 439 err = devm_gpio_request_one(&spi->dev, 440 ks->pdata->reset_gpio, 441 flags, "switch-reset"); 442 if (err) { 443 dev_err(&spi->dev, 444 "failed to get reset-gpios: %d\n", err); 445 return -EIO; 446 } 447 448 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0); 449 } 450 451 spi_set_drvdata(spi, ks); 452 453 spi->mode = SPI_MODE_0; 454 spi->bits_per_word = 8; 455 err = spi_setup(spi); 456 if (err) { 457 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err); 458 return err; 459 } 460 461 err = ks8995_get_revision(ks); 462 if (err) 463 return err; 464 465 ks->regs_attr.size = ks->chip->regs_size; 466 memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr)); 467 468 err = ks8995_reset(ks); 469 if (err) 470 return err; 471 472 err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr); 473 if (err) { 474 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n", 475 err); 476 return err; 477 } 478 479 dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n", 480 ks->chip->name, ks->chip->chip_id, ks->revision_id); 481 482 return 0; 483 } 484 485 static int ks8995_remove(struct spi_device *spi) 486 { 487 struct ks8995_switch *ks = spi_get_drvdata(spi); 488 489 sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr); 490 491 /* assert reset */ 492 if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) 493 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1); 494 495 return 0; 496 } 497 498 /* ------------------------------------------------------------------------ */ 499 static struct spi_driver ks8995_driver = { 500 .driver = { 501 .name = "spi-ks8995", 502 }, 503 .probe = ks8995_probe, 504 .remove = ks8995_remove, 505 .id_table = ks8995_id, 506 }; 507 508 module_spi_driver(ks8995_driver); 509 510 MODULE_DESCRIPTION(DRV_DESC); 511 MODULE_VERSION(DRV_VERSION); 512 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); 513 MODULE_LICENSE("GPL v2"); 514