drivers/net/phy/spi_ks8995.c

   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/gpio/consumer.h>
  22 #include <linux/of.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 #define KSZ8795_REGS_SIZE       0x100
  81
  82 #define ID1_CHIPID_M            0xf
  83 #define ID1_CHIPID_S            4
  84 #define ID1_REVISION_M          0x7
  85 #define ID1_REVISION_S          1
  86 #define ID1_START_SW            1       /* start the switch */
  87
  88 #define FAMILY_KS8995           0x95
  89 #define FAMILY_KSZ8795          0x87
  90 #define CHIPID_M                0
  91 #define KS8995_CHIP_ID          0x00
  92 #define KSZ8864_CHIP_ID         0x01
  93 #define KSZ8795_CHIP_ID         0x09
  94
  95 #define KS8995_CMD_WRITE        0x02U
  96 #define KS8995_CMD_READ         0x03U
  97
  98 #define KS8995_RESET_DELAY      10 /* usec */
  99
 100 enum ks8995_chip_variant {
 101         ks8995,
 102         ksz8864,
 103         ksz8795,
 104         max_variant
 105 };
 106
 107 struct ks8995_chip_params {
 108         char *name;
 109         int family_id;
 110         int chip_id;
 111         int regs_size;
 112         int addr_width;
 113         int addr_shift;
 114 };
 115
 116 static const struct ks8995_chip_params ks8995_chip[] = {
 117         [ks8995] = {
 118                 .name = "KS8995MA",
 119                 .family_id = FAMILY_KS8995,
 120                 .chip_id = KS8995_CHIP_ID,
 121                 .regs_size = KS8995_REGS_SIZE,
 122                 .addr_width = 8,
 123                 .addr_shift = 0,
 124         },
 125         [ksz8864] = {
 126                 .name = "KSZ8864RMN",
 127                 .family_id = FAMILY_KS8995,
 128                 .chip_id = KSZ8864_CHIP_ID,
 129                 .regs_size = KSZ8864_REGS_SIZE,
 130                 .addr_width = 8,
 131                 .addr_shift = 0,
 132         },
 133         [ksz8795] = {
 134                 .name = "KSZ8795CLX",
 135                 .family_id = FAMILY_KSZ8795,
 136                 .chip_id = KSZ8795_CHIP_ID,
 137                 .regs_size = KSZ8795_REGS_SIZE,
 138                 .addr_width = 12,
 139                 .addr_shift = 1,
 140         },
 141 };
 142
 143 struct ks8995_pdata {
 144         int reset_gpio;
 145         enum of_gpio_flags reset_gpio_flags;
 146 };
 147
 148 struct ks8995_switch {
 149         struct spi_device       *spi;
 150         struct mutex            lock;
 151         struct ks8995_pdata     *pdata;
 152         struct bin_attribute    regs_attr;
 153         const struct ks8995_chip_params *chip;
 154         int                     revision_id;
 155 };
 156
 157 static const struct spi_device_id ks8995_id[] = {
 158         {"ks8995", ks8995},
 159         {"ksz8864", ksz8864},
 160         {"ksz8795", ksz8795},
 161         { }
 162 };
 163 MODULE_DEVICE_TABLE(spi, ks8995_id);
 164
 165 static inline u8 get_chip_id(u8 val)
 166 {
 167         return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
 168 }
 169
 170 static inline u8 get_chip_rev(u8 val)
 171 {
 172         return (val >> ID1_REVISION_S) & ID1_REVISION_M;
 173 }
 174
 175 /* create_spi_cmd - create a chip specific SPI command header
 176  * @ks: pointer to switch instance
 177  * @cmd: SPI command for switch
 178  * @address: register address for command
 179  *
 180  * Different chip families use different bit pattern to address the switches
 181  * registers:
 182  *
 183  * KS8995: 8bit command + 8bit address
 184  * KSZ8795: 3bit command + 12bit address + 1bit TR (?)
 185  */
 186 static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
 187                                     unsigned address)
 188 {
 189         u16 result = cmd;
 190
 191         /* make room for address (incl. address shift) */
 192         result <<= ks->chip->addr_width + ks->chip->addr_shift;
 193         /* add address */
 194         result |= address << ks->chip->addr_shift;
 195         /* SPI protocol needs big endian */
 196         return cpu_to_be16(result);
 197 }
 198 /* ------------------------------------------------------------------------ */
 199 static int ks8995_read(struct ks8995_switch *ks, char *buf,
 200                  unsigned offset, size_t count)
 201 {
 202         __be16 cmd;
 203         struct spi_transfer t[2];
 204         struct spi_message m;
 205         int err;
 206
 207         cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
 208         spi_message_init(&m);
 209
 210         memset(&t, 0, sizeof(t));
 211
 212         t[0].tx_buf = &cmd;
 213         t[0].len = sizeof(cmd);
 214         spi_message_add_tail(&t[0], &m);
 215
 216         t[1].rx_buf = buf;
 217         t[1].len = count;
 218         spi_message_add_tail(&t[1], &m);
 219
 220         mutex_lock(&ks->lock);
 221         err = spi_sync(ks->spi, &m);
 222         mutex_unlock(&ks->lock);
 223
 224         return err ? err : count;
 225 }
 226
 227 static int ks8995_write(struct ks8995_switch *ks, char *buf,
 228                  unsigned offset, size_t count)
 229 {
 230         __be16 cmd;
 231         struct spi_transfer t[2];
 232         struct spi_message m;
 233         int err;
 234
 235         cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
 236         spi_message_init(&m);
 237
 238         memset(&t, 0, sizeof(t));
 239
 240         t[0].tx_buf = &cmd;
 241         t[0].len = sizeof(cmd);
 242         spi_message_add_tail(&t[0], &m);
 243
 244         t[1].tx_buf = buf;
 245         t[1].len = count;
 246         spi_message_add_tail(&t[1], &m);
 247
 248         mutex_lock(&ks->lock);
 249         err = spi_sync(ks->spi, &m);
 250         mutex_unlock(&ks->lock);
 251
 252         return err ? err : count;
 253 }
 254
 255 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
 256 {
 257         return ks8995_read(ks, buf, addr, 1) != 1;
 258 }
 259
 260 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
 261 {
 262         char buf = val;
 263
 264         return ks8995_write(ks, &buf, addr, 1) != 1;
 265 }
 266
 267 /* ------------------------------------------------------------------------ */
 268
 269 static int ks8995_stop(struct ks8995_switch *ks)
 270 {
 271         return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
 272 }
 273
 274 static int ks8995_start(struct ks8995_switch *ks)
 275 {
 276         return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
 277 }
 278
 279 static int ks8995_reset(struct ks8995_switch *ks)
 280 {
 281         int err;
 282
 283         err = ks8995_stop(ks);
 284         if (err)
 285                 return err;
 286
 287         udelay(KS8995_RESET_DELAY);
 288
 289         return ks8995_start(ks);
 290 }
 291
 292 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj,
 293         struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
 294 {
 295         struct device *dev;
 296         struct ks8995_switch *ks8995;
 297
 298         dev = container_of(kobj, struct device, kobj);
 299         ks8995 = dev_get_drvdata(dev);
 300
 301         return ks8995_read(ks8995, buf, off, count);
 302 }
 303
 304 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj,
 305         struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
 306 {
 307         struct device *dev;
 308         struct ks8995_switch *ks8995;
 309
 310         dev = container_of(kobj, struct device, kobj);
 311         ks8995 = dev_get_drvdata(dev);
 312
 313         return ks8995_write(ks8995, buf, off, count);
 314 }
 315
 316 /* ks8995_get_revision - get chip revision
 317  * @ks: pointer to switch instance
 318  *
 319  * Verify chip family and id and get chip revision.
 320  */
 321 static int ks8995_get_revision(struct ks8995_switch *ks)
 322 {
 323         int err;
 324         u8 id0, id1, ksz8864_id;
 325
 326         /* read family id */
 327         err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
 328         if (err) {
 329                 err = -EIO;
 330                 goto err_out;
 331         }
 332
 333         /* verify family id */
 334         if (id0 != ks->chip->family_id) {
 335                 dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
 336                         ks->chip->family_id, id0);
 337                 err = -ENODEV;
 338                 goto err_out;
 339         }
 340
 341         switch (ks->chip->family_id) {
 342         case FAMILY_KS8995:
 343                 /* try reading chip id at CHIP ID1 */
 344                 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
 345                 if (err) {
 346                         err = -EIO;
 347                         goto err_out;
 348                 }
 349
 350                 /* verify chip id */
 351                 if ((get_chip_id(id1) == CHIPID_M) &&
 352                     (get_chip_id(id1) == ks->chip->chip_id)) {
 353                         /* KS8995MA */
 354                         ks->revision_id = get_chip_rev(id1);
 355                 } else if (get_chip_id(id1) != CHIPID_M) {
 356                         /* KSZ8864RMN */
 357                         err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
 358                         if (err) {
 359                                 err = -EIO;
 360                                 goto err_out;
 361                         }
 362
 363                         if ((ksz8864_id & 0x80) &&
 364                             (ks->chip->chip_id == KSZ8864_CHIP_ID)) {
 365                                 ks->revision_id = get_chip_rev(id1);
 366                         }
 367
 368                 } else {
 369                         dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
 370                                 id1);
 371                         err = -ENODEV;
 372                 }
 373                 break;
 374         case FAMILY_KSZ8795:
 375                 /* try reading chip id at CHIP ID1 */
 376                 err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
 377                 if (err) {
 378                         err = -EIO;
 379                         goto err_out;
 380                 }
 381
 382                 if (get_chip_id(id1) == ks->chip->chip_id) {
 383                         ks->revision_id = get_chip_rev(id1);
 384                 } else {
 385                         dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
 386                                 id1);
 387                         err = -ENODEV;
 388                 }
 389                 break;
 390         default:
 391                 dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
 392                 err = -ENODEV;
 393                 break;
 394         }
 395 err_out:
 396         return err;
 397 }
 398
 399 /* ks8995_parse_dt - setup platform data from devicetree
 400  * @ks: pointer to switch instance
 401  *
 402  * Parses supported DT properties and sets up platform data
 403  * accordingly.
 404  */
 405 static void ks8995_parse_dt(struct ks8995_switch *ks)
 406 {
 407         struct device_node *np = ks->spi->dev.of_node;
 408         struct ks8995_pdata *pdata = ks->pdata;
 409
 410         if (!np)
 411                 return;
 412
 413         pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0,
 414                 &pdata->reset_gpio_flags);
 415 }
 416
 417 static const struct bin_attribute ks8995_registers_attr = {
 418         .attr = {
 419                 .name   = "registers",
 420                 .mode   = S_IRUSR | S_IWUSR,
 421         },
 422         .size   = KS8995_REGS_SIZE,
 423         .read   = ks8995_registers_read,
 424         .write  = ks8995_registers_write,
 425 };
 426
 427 /* ------------------------------------------------------------------------ */
 428 static int ks8995_probe(struct spi_device *spi)
 429 {
 430         struct ks8995_switch *ks;
 431         int err;
 432         int variant = spi_get_device_id(spi)->driver_data;
 433
 434         if (variant >= max_variant) {
 435                 dev_err(&spi->dev, "bad chip variant %d\n", variant);
 436                 return -ENODEV;
 437         }
 438
 439         ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
 440         if (!ks)
 441                 return -ENOMEM;
 442
 443         mutex_init(&ks->lock);
 444         ks->spi = spi_dev_get(spi);
 445         ks->chip = &ks8995_chip[variant];
 446
 447         if (ks->spi->dev.of_node) {
 448                 ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata),
 449                                          GFP_KERNEL);
 450                 if (!ks->pdata)
 451                         return -ENOMEM;
 452
 453                 ks->pdata->reset_gpio = -1;
 454
 455                 ks8995_parse_dt(ks);
 456         }
 457
 458         if (!ks->pdata)
 459                 ks->pdata = spi->dev.platform_data;
 460
 461         /* de-assert switch reset */
 462         if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) {
 463                 unsigned long flags;
 464
 465                 flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ?
 466                          GPIOF_ACTIVE_LOW : 0);
 467
 468                 err = devm_gpio_request_one(&spi->dev,
 469                                             ks->pdata->reset_gpio,
 470                                             flags, "switch-reset");
 471                 if (err) {
 472                         dev_err(&spi->dev,
 473                                 "failed to get reset-gpios: %d\n", err);
 474                         return -EIO;
 475                 }
 476
 477                 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0);
 478         }
 479
 480         spi_set_drvdata(spi, ks);
 481
 482         spi->mode = SPI_MODE_0;
 483         spi->bits_per_word = 8;
 484         err = spi_setup(spi);
 485         if (err) {
 486                 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
 487                 return err;
 488         }
 489
 490         err = ks8995_get_revision(ks);
 491         if (err)
 492                 return err;
 493
 494         ks->regs_attr.size = ks->chip->regs_size;
 495         memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));
 496
 497         err = ks8995_reset(ks);
 498         if (err)
 499                 return err;
 500
 501         err = sysfs_create_bin_file(&spi->dev.kobj, &ks->regs_attr);
 502         if (err) {
 503                 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n",
 504                                     err);
 505                 return err;
 506         }
 507
 508         dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
 509                  ks->chip->name, ks->chip->chip_id, ks->revision_id);
 510
 511         return 0;
 512 }
 513
 514 static int ks8995_remove(struct spi_device *spi)
 515 {
 516         struct ks8995_switch *ks = spi_get_drvdata(spi);
 517
 518         sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);
 519
 520         /* assert reset */
 521         if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio))
 522                 gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1);
 523
 524         return 0;
 525 }
 526
 527 /* ------------------------------------------------------------------------ */
 528 static struct spi_driver ks8995_driver = {
 529         .driver = {
 530                 .name       = "spi-ks8995",
 531         },
 532         .probe    = ks8995_probe,
 533         .remove   = ks8995_remove,
 534         .id_table = ks8995_id,
 535 };
 536
 537 module_spi_driver(ks8995_driver);
 538
 539 MODULE_DESCRIPTION(DRV_DESC);
 540 MODULE_VERSION(DRV_VERSION);
 541 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
 542 MODULE_LICENSE("GPL v2");