drivers/net/phy/sfp.c

   1 #include <linux/delay.h>
   2 #include <linux/gpio/consumer.h>
   3 #include <linux/i2c.h>
   4 #include <linux/interrupt.h>
   5 #include <linux/jiffies.h>
   6 #include <linux/module.h>
   7 #include <linux/mutex.h>
   8 #include <linux/of.h>
   9 #include <linux/phy.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/rtnetlink.h>
  12 #include <linux/slab.h>
  13 #include <linux/workqueue.h>
  14
  15 #include "mdio-i2c.h"
  16 #include "sfp.h"
  17 #include "swphy.h"
  18
  19 enum {
  20         GPIO_MODDEF0,
  21         GPIO_LOS,
  22         GPIO_TX_FAULT,
  23         GPIO_TX_DISABLE,
  24         GPIO_RATE_SELECT,
  25         GPIO_MAX,
  26
  27         SFP_F_PRESENT = BIT(GPIO_MODDEF0),
  28         SFP_F_LOS = BIT(GPIO_LOS),
  29         SFP_F_TX_FAULT = BIT(GPIO_TX_FAULT),
  30         SFP_F_TX_DISABLE = BIT(GPIO_TX_DISABLE),
  31         SFP_F_RATE_SELECT = BIT(GPIO_RATE_SELECT),
  32
  33         SFP_E_INSERT = 0,
  34         SFP_E_REMOVE,
  35         SFP_E_DEV_DOWN,
  36         SFP_E_DEV_UP,
  37         SFP_E_TX_FAULT,
  38         SFP_E_TX_CLEAR,
  39         SFP_E_LOS_HIGH,
  40         SFP_E_LOS_LOW,
  41         SFP_E_TIMEOUT,
  42
  43         SFP_MOD_EMPTY = 0,
  44         SFP_MOD_PROBE,
  45         SFP_MOD_HPOWER,
  46         SFP_MOD_PRESENT,
  47         SFP_MOD_ERROR,
  48
  49         SFP_DEV_DOWN = 0,
  50         SFP_DEV_UP,
  51
  52         SFP_S_DOWN = 0,
  53         SFP_S_INIT,
  54         SFP_S_WAIT_LOS,
  55         SFP_S_LINK_UP,
  56         SFP_S_TX_FAULT,
  57         SFP_S_REINIT,
  58         SFP_S_TX_DISABLE,
  59 };
  60
  61 static const char *gpio_of_names[] = {
  62         "mod-def0",
  63         "los",
  64         "tx-fault",
  65         "tx-disable",
  66         "rate-select0",
  67 };
  68
  69 static const enum gpiod_flags gpio_flags[] = {
  70         GPIOD_IN,
  71         GPIOD_IN,
  72         GPIOD_IN,
  73         GPIOD_ASIS,
  74         GPIOD_ASIS,
  75 };
  76
  77 #define T_INIT_JIFFIES  msecs_to_jiffies(300)
  78 #define T_RESET_US      10
  79 #define T_FAULT_RECOVER msecs_to_jiffies(1000)
  80
  81 /* SFP module presence detection is poor: the three MOD DEF signals are
  82  * the same length on the PCB, which means it's possible for MOD DEF 0 to
  83  * connect before the I2C bus on MOD DEF 1/2.
  84  *
  85  * The SFP MSA specifies 300ms as t_init (the time taken for TX_FAULT to
  86  * be deasserted) but makes no mention of the earliest time before we can
  87  * access the I2C EEPROM.  However, Avago modules require 300ms.
  88  */
  89 #define T_PROBE_INIT    msecs_to_jiffies(300)
  90 #define T_HPOWER_LEVEL  msecs_to_jiffies(300)
  91 #define T_PROBE_RETRY   msecs_to_jiffies(100)
  92
  93 /* SFP modules appear to always have their PHY configured for bus address
  94  * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
  95  */
  96 #define SFP_PHY_ADDR    22
  97
  98 /* Give this long for the PHY to reset. */
  99 #define T_PHY_RESET_MS  50
 100
 101 static DEFINE_MUTEX(sfp_mutex);
 102
 103 struct sff_data {
 104         unsigned int gpios;
 105         bool (*module_supported)(const struct sfp_eeprom_id *id);
 106 };
 107
 108 struct sfp {
 109         struct device *dev;
 110         struct i2c_adapter *i2c;
 111         struct mii_bus *i2c_mii;
 112         struct sfp_bus *sfp_bus;
 113         struct phy_device *mod_phy;
 114         const struct sff_data *type;
 115         u32 max_power_mW;
 116
 117         unsigned int (*get_state)(struct sfp *);
 118         void (*set_state)(struct sfp *, unsigned int);
 119         int (*read)(struct sfp *, bool, u8, void *, size_t);
 120         int (*write)(struct sfp *, bool, u8, void *, size_t);
 121
 122         struct gpio_desc *gpio[GPIO_MAX];
 123
 124         unsigned int state;
 125         struct delayed_work poll;
 126         struct delayed_work timeout;
 127         struct mutex sm_mutex;
 128         unsigned char sm_mod_state;
 129         unsigned char sm_dev_state;
 130         unsigned short sm_state;
 131         unsigned int sm_retries;
 132
 133         struct sfp_eeprom_id id;
 134 };
 135
 136 static bool sff_module_supported(const struct sfp_eeprom_id *id)
 137 {
 138         return id->base.phys_id == SFP_PHYS_ID_SFF &&
 139                id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP;
 140 }
 141
 142 static const struct sff_data sff_data = {
 143         .gpios = SFP_F_LOS | SFP_F_TX_FAULT | SFP_F_TX_DISABLE,
 144         .module_supported = sff_module_supported,
 145 };
 146
 147 static bool sfp_module_supported(const struct sfp_eeprom_id *id)
 148 {
 149         return id->base.phys_id == SFP_PHYS_ID_SFP &&
 150                id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP;
 151 }
 152
 153 static const struct sff_data sfp_data = {
 154         .gpios = SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT |
 155                  SFP_F_TX_DISABLE | SFP_F_RATE_SELECT,
 156         .module_supported = sfp_module_supported,
 157 };
 158
 159 static const struct of_device_id sfp_of_match[] = {
 160         { .compatible = "sff,sff", .data = &sff_data, },
 161         { .compatible = "sff,sfp", .data = &sfp_data, },
 162         { },
 163 };
 164 MODULE_DEVICE_TABLE(of, sfp_of_match);
 165
 166 static unsigned long poll_jiffies;
 167
 168 static unsigned int sfp_gpio_get_state(struct sfp *sfp)
 169 {
 170         unsigned int i, state, v;
 171
 172         for (i = state = 0; i < GPIO_MAX; i++) {
 173                 if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
 174                         continue;
 175
 176                 v = gpiod_get_value_cansleep(sfp->gpio[i]);
 177                 if (v)
 178                         state |= BIT(i);
 179         }
 180
 181         return state;
 182 }
 183
 184 static unsigned int sff_gpio_get_state(struct sfp *sfp)
 185 {
 186         return sfp_gpio_get_state(sfp) | SFP_F_PRESENT;
 187 }
 188
 189 static void sfp_gpio_set_state(struct sfp *sfp, unsigned int state)
 190 {
 191         if (state & SFP_F_PRESENT) {
 192                 /* If the module is present, drive the signals */
 193                 if (sfp->gpio[GPIO_TX_DISABLE])
 194                         gpiod_direction_output(sfp->gpio[GPIO_TX_DISABLE],
 195                                                state & SFP_F_TX_DISABLE);
 196                 if (state & SFP_F_RATE_SELECT)
 197                         gpiod_direction_output(sfp->gpio[GPIO_RATE_SELECT],
 198                                                state & SFP_F_RATE_SELECT);
 199         } else {
 200                 /* Otherwise, let them float to the pull-ups */
 201                 if (sfp->gpio[GPIO_TX_DISABLE])
 202                         gpiod_direction_input(sfp->gpio[GPIO_TX_DISABLE]);
 203                 if (state & SFP_F_RATE_SELECT)
 204                         gpiod_direction_input(sfp->gpio[GPIO_RATE_SELECT]);
 205         }
 206 }
 207
 208 static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
 209                         size_t len)
 210 {
 211         struct i2c_msg msgs[2];
 212         u8 bus_addr = a2 ? 0x51 : 0x50;
 213         int ret;
 214
 215         msgs[0].addr = bus_addr;
 216         msgs[0].flags = 0;
 217         msgs[0].len = 1;
 218         msgs[0].buf = &dev_addr;
 219         msgs[1].addr = bus_addr;
 220         msgs[1].flags = I2C_M_RD;
 221         msgs[1].len = len;
 222         msgs[1].buf = buf;
 223
 224         ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
 225         if (ret < 0)
 226                 return ret;
 227
 228         return ret == ARRAY_SIZE(msgs) ? len : 0;
 229 }
 230
 231 static int sfp_i2c_write(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
 232         size_t len)
 233 {
 234         struct i2c_msg msgs[1];
 235         u8 bus_addr = a2 ? 0x51 : 0x50;
 236         int ret;
 237
 238         msgs[0].addr = bus_addr;
 239         msgs[0].flags = 0;
 240         msgs[0].len = 1 + len;
 241         msgs[0].buf = kmalloc(1 + len, GFP_KERNEL);
 242         if (!msgs[0].buf)
 243                 return -ENOMEM;
 244
 245         msgs[0].buf[0] = dev_addr;
 246         memcpy(&msgs[0].buf[1], buf, len);
 247
 248         ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
 249
 250         kfree(msgs[0].buf);
 251
 252         if (ret < 0)
 253                 return ret;
 254
 255         return ret == ARRAY_SIZE(msgs) ? len : 0;
 256 }
 257
 258 static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
 259 {
 260         struct mii_bus *i2c_mii;
 261         int ret;
 262
 263         if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
 264                 return -EINVAL;
 265
 266         sfp->i2c = i2c;
 267         sfp->read = sfp_i2c_read;
 268         sfp->write = sfp_i2c_write;
 269
 270         i2c_mii = mdio_i2c_alloc(sfp->dev, i2c);
 271         if (IS_ERR(i2c_mii))
 272                 return PTR_ERR(i2c_mii);
 273
 274         i2c_mii->name = "SFP I2C Bus";
 275         i2c_mii->phy_mask = ~0;
 276
 277         ret = mdiobus_register(i2c_mii);
 278         if (ret < 0) {
 279                 mdiobus_free(i2c_mii);
 280                 return ret;
 281         }
 282
 283         sfp->i2c_mii = i2c_mii;
 284
 285         return 0;
 286 }
 287
 288 /* Interface */
 289 static unsigned int sfp_get_state(struct sfp *sfp)
 290 {
 291         return sfp->get_state(sfp);
 292 }
 293
 294 static void sfp_set_state(struct sfp *sfp, unsigned int state)
 295 {
 296         sfp->set_state(sfp, state);
 297 }
 298
 299 static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
 300 {
 301         return sfp->read(sfp, a2, addr, buf, len);
 302 }
 303
 304 static int sfp_write(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
 305 {
 306         return sfp->write(sfp, a2, addr, buf, len);
 307 }
 308
 309 static unsigned int sfp_check(void *buf, size_t len)
 310 {
 311         u8 *p, check;
 312
 313         for (p = buf, check = 0; len; p++, len--)
 314                 check += *p;
 315
 316         return check;
 317 }
 318
 319 /* Helpers */
 320 static void sfp_module_tx_disable(struct sfp *sfp)
 321 {
 322         dev_dbg(sfp->dev, "tx disable %u -> %u\n",
 323                 sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 1);
 324         sfp->state |= SFP_F_TX_DISABLE;
 325         sfp_set_state(sfp, sfp->state);
 326 }
 327
 328 static void sfp_module_tx_enable(struct sfp *sfp)
 329 {
 330         dev_dbg(sfp->dev, "tx disable %u -> %u\n",
 331                 sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 0);
 332         sfp->state &= ~SFP_F_TX_DISABLE;
 333         sfp_set_state(sfp, sfp->state);
 334 }
 335
 336 static void sfp_module_tx_fault_reset(struct sfp *sfp)
 337 {
 338         unsigned int state = sfp->state;
 339
 340         if (state & SFP_F_TX_DISABLE)
 341                 return;
 342
 343         sfp_set_state(sfp, state | SFP_F_TX_DISABLE);
 344
 345         udelay(T_RESET_US);
 346
 347         sfp_set_state(sfp, state);
 348 }
 349
 350 /* SFP state machine */
 351 static void sfp_sm_set_timer(struct sfp *sfp, unsigned int timeout)
 352 {
 353         if (timeout)
 354                 mod_delayed_work(system_power_efficient_wq, &sfp->timeout,
 355                                  timeout);
 356         else
 357                 cancel_delayed_work(&sfp->timeout);
 358 }
 359
 360 static void sfp_sm_next(struct sfp *sfp, unsigned int state,
 361                         unsigned int timeout)
 362 {
 363         sfp->sm_state = state;
 364         sfp_sm_set_timer(sfp, timeout);
 365 }
 366
 367 static void sfp_sm_ins_next(struct sfp *sfp, unsigned int state,
 368                             unsigned int timeout)
 369 {
 370         sfp->sm_mod_state = state;
 371         sfp_sm_set_timer(sfp, timeout);
 372 }
 373
 374 static void sfp_sm_phy_detach(struct sfp *sfp)
 375 {
 376         phy_stop(sfp->mod_phy);
 377         sfp_remove_phy(sfp->sfp_bus);
 378         phy_device_remove(sfp->mod_phy);
 379         phy_device_free(sfp->mod_phy);
 380         sfp->mod_phy = NULL;
 381 }
 382
 383 static void sfp_sm_probe_phy(struct sfp *sfp)
 384 {
 385         struct phy_device *phy;
 386         int err;
 387
 388         msleep(T_PHY_RESET_MS);
 389
 390         phy = mdiobus_scan(sfp->i2c_mii, SFP_PHY_ADDR);
 391         if (phy == ERR_PTR(-ENODEV)) {
 392                 dev_info(sfp->dev, "no PHY detected\n");
 393                 return;
 394         }
 395         if (IS_ERR(phy)) {
 396                 dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
 397                 return;
 398         }
 399
 400         err = sfp_add_phy(sfp->sfp_bus, phy);
 401         if (err) {
 402                 phy_device_remove(phy);
 403                 phy_device_free(phy);
 404                 dev_err(sfp->dev, "sfp_add_phy failed: %d\n", err);
 405                 return;
 406         }
 407
 408         sfp->mod_phy = phy;
 409         phy_start(phy);
 410 }
 411
 412 static void sfp_sm_link_up(struct sfp *sfp)
 413 {
 414         sfp_link_up(sfp->sfp_bus);
 415         sfp_sm_next(sfp, SFP_S_LINK_UP, 0);
 416 }
 417
 418 static void sfp_sm_link_down(struct sfp *sfp)
 419 {
 420         sfp_link_down(sfp->sfp_bus);
 421 }
 422
 423 static void sfp_sm_link_check_los(struct sfp *sfp)
 424 {
 425         unsigned int los = sfp->state & SFP_F_LOS;
 426
 427         /* If neither SFP_OPTIONS_LOS_INVERTED nor SFP_OPTIONS_LOS_NORMAL
 428          * are set, we assume that no LOS signal is available.
 429          */
 430         if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED))
 431                 los ^= SFP_F_LOS;
 432         else if (!(sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL)))
 433                 los = 0;
 434
 435         if (los)
 436                 sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
 437         else
 438                 sfp_sm_link_up(sfp);
 439 }
 440
 441 static bool sfp_los_event_active(struct sfp *sfp, unsigned int event)
 442 {
 443         return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
 444                 event == SFP_E_LOS_LOW) ||
 445                (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
 446                 event == SFP_E_LOS_HIGH);
 447 }
 448
 449 static bool sfp_los_event_inactive(struct sfp *sfp, unsigned int event)
 450 {
 451         return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
 452                 event == SFP_E_LOS_HIGH) ||
 453                (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
 454                 event == SFP_E_LOS_LOW);
 455 }
 456
 457 static void sfp_sm_fault(struct sfp *sfp, bool warn)
 458 {
 459         if (sfp->sm_retries && !--sfp->sm_retries) {
 460                 dev_err(sfp->dev,
 461                         "module persistently indicates fault, disabling\n");
 462                 sfp_sm_next(sfp, SFP_S_TX_DISABLE, 0);
 463         } else {
 464                 if (warn)
 465                         dev_err(sfp->dev, "module transmit fault indicated\n");
 466
 467                 sfp_sm_next(sfp, SFP_S_TX_FAULT, T_FAULT_RECOVER);
 468         }
 469 }
 470
 471 static void sfp_sm_mod_init(struct sfp *sfp)
 472 {
 473         sfp_module_tx_enable(sfp);
 474
 475         /* Wait t_init before indicating that the link is up, provided the
 476          * current state indicates no TX_FAULT.  If TX_FAULT clears before
 477          * this time, that's fine too.
 478          */
 479         sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
 480         sfp->sm_retries = 5;
 481
 482         /* Setting the serdes link mode is guesswork: there's no
 483          * field in the EEPROM which indicates what mode should
 484          * be used.
 485          *
 486          * If it's a gigabit-only fiber module, it probably does
 487          * not have a PHY, so switch to 802.3z negotiation mode.
 488          * Otherwise, switch to SGMII mode (which is required to
 489          * support non-gigabit speeds) and probe for a PHY.
 490          */
 491         if (sfp->id.base.e1000_base_t ||
 492             sfp->id.base.e100_base_lx ||
 493             sfp->id.base.e100_base_fx)
 494                 sfp_sm_probe_phy(sfp);
 495 }
 496
 497 static int sfp_sm_mod_hpower(struct sfp *sfp)
 498 {
 499         u32 power;
 500         u8 val;
 501         int err;
 502
 503         power = 1000;
 504         if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_POWER_DECL))
 505                 power = 1500;
 506         if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_HIGH_POWER_LEVEL))
 507                 power = 2000;
 508
 509         if (sfp->id.ext.sff8472_compliance == SFP_SFF8472_COMPLIANCE_NONE &&
 510             (sfp->id.ext.diagmon & (SFP_DIAGMON_DDM | SFP_DIAGMON_ADDRMODE)) !=
 511             SFP_DIAGMON_DDM) {
 512                 /* The module appears not to implement bus address 0xa2,
 513                  * or requires an address change sequence, so assume that
 514                  * the module powers up in the indicated power mode.
 515                  */
 516                 if (power > sfp->max_power_mW) {
 517                         dev_err(sfp->dev,
 518                                 "Host does not support %u.%uW modules\n",
 519                                 power / 1000, (power / 100) % 10);
 520                         return -EINVAL;
 521                 }
 522                 return 0;
 523         }
 524
 525         if (power > sfp->max_power_mW) {
 526                 dev_warn(sfp->dev,
 527                          "Host does not support %u.%uW modules, module left in power mode 1\n",
 528                          power / 1000, (power / 100) % 10);
 529                 return 0;
 530         }
 531
 532         if (power <= 1000)
 533                 return 0;
 534
 535         err = sfp_read(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
 536         if (err != sizeof(val)) {
 537                 dev_err(sfp->dev, "Failed to read EEPROM: %d\n", err);
 538                 err = -EAGAIN;
 539                 goto err;
 540         }
 541
 542         val |= BIT(0);
 543
 544         err = sfp_write(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
 545         if (err != sizeof(val)) {
 546                 dev_err(sfp->dev, "Failed to write EEPROM: %d\n", err);
 547                 err = -EAGAIN;
 548                 goto err;
 549         }
 550
 551         dev_info(sfp->dev, "Module switched to %u.%uW power level\n",
 552                  power / 1000, (power / 100) % 10);
 553         return T_HPOWER_LEVEL;
 554
 555 err:
 556         return err;
 557 }
 558
 559 static int sfp_sm_mod_probe(struct sfp *sfp)
 560 {
 561         /* SFP module inserted - read I2C data */
 562         struct sfp_eeprom_id id;
 563         u8 check;
 564         int ret;
 565
 566         ret = sfp_read(sfp, false, 0, &id, sizeof(id));
 567         if (ret < 0) {
 568                 dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
 569                 return -EAGAIN;
 570         }
 571
 572         if (ret != sizeof(id)) {
 573                 dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
 574                 return -EAGAIN;
 575         }
 576
 577         /* Validate the checksum over the base structure */
 578         check = sfp_check(&id.base, sizeof(id.base) - 1);
 579         if (check != id.base.cc_base) {
 580                 dev_err(sfp->dev,
 581                         "EEPROM base structure checksum failure: 0x%02x\n",
 582                         check);
 583                 print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
 584                                16, 1, &id, sizeof(id.base) - 1, true);
 585                 return -EINVAL;
 586         }
 587
 588         check = sfp_check(&id.ext, sizeof(id.ext) - 1);
 589         if (check != id.ext.cc_ext) {
 590                 dev_err(sfp->dev,
 591                         "EEPROM extended structure checksum failure: 0x%02x\n",
 592                         check);
 593                 memset(&id.ext, 0, sizeof(id.ext));
 594         }
 595
 596         sfp->id = id;
 597
 598         dev_info(sfp->dev, "module %.*s %.*s rev %.*s sn %.*s dc %.*s\n",
 599                  (int)sizeof(id.base.vendor_name), id.base.vendor_name,
 600                  (int)sizeof(id.base.vendor_pn), id.base.vendor_pn,
 601                  (int)sizeof(id.base.vendor_rev), id.base.vendor_rev,
 602                  (int)sizeof(id.ext.vendor_sn), id.ext.vendor_sn,
 603                  (int)sizeof(id.ext.datecode), id.ext.datecode);
 604
 605         /* Check whether we support this module */
 606         if (!sfp->type->module_supported(&sfp->id)) {
 607                 dev_err(sfp->dev,
 608                         "module is not supported - phys id 0x%02x 0x%02x\n",
 609                         sfp->id.base.phys_id, sfp->id.base.phys_ext_id);
 610                 return -EINVAL;
 611         }
 612
 613         /* If the module requires address swap mode, warn about it */
 614         if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
 615                 dev_warn(sfp->dev,
 616                          "module address swap to access page 0xA2 is not supported.\n");
 617
 618         ret = sfp_module_insert(sfp->sfp_bus, &sfp->id);
 619         if (ret < 0)
 620                 return ret;
 621
 622         return sfp_sm_mod_hpower(sfp);
 623 }
 624
 625 static void sfp_sm_mod_remove(struct sfp *sfp)
 626 {
 627         sfp_module_remove(sfp->sfp_bus);
 628
 629         if (sfp->mod_phy)
 630                 sfp_sm_phy_detach(sfp);
 631
 632         sfp_module_tx_disable(sfp);
 633
 634         memset(&sfp->id, 0, sizeof(sfp->id));
 635
 636         dev_info(sfp->dev, "module removed\n");
 637 }
 638
 639 static void sfp_sm_event(struct sfp *sfp, unsigned int event)
 640 {
 641         mutex_lock(&sfp->sm_mutex);
 642
 643         dev_dbg(sfp->dev, "SM: enter %u:%u:%u event %u\n",
 644                 sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state, event);
 645
 646         /* This state machine tracks the insert/remove state of
 647          * the module, and handles probing the on-board EEPROM.
 648          */
 649         switch (sfp->sm_mod_state) {
 650         default:
 651                 if (event == SFP_E_INSERT) {
 652                         sfp_module_tx_disable(sfp);
 653                         sfp_sm_ins_next(sfp, SFP_MOD_PROBE, T_PROBE_INIT);
 654                 }
 655                 break;
 656
 657         case SFP_MOD_PROBE:
 658                 if (event == SFP_E_REMOVE) {
 659                         sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
 660                 } else if (event == SFP_E_TIMEOUT) {
 661                         int val = sfp_sm_mod_probe(sfp);
 662
 663                         if (val == 0)
 664                                 sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
 665                         else if (val > 0)
 666                                 sfp_sm_ins_next(sfp, SFP_MOD_HPOWER, val);
 667                         else if (val != -EAGAIN)
 668                                 sfp_sm_ins_next(sfp, SFP_MOD_ERROR, 0);
 669                         else
 670                                 sfp_sm_set_timer(sfp, T_PROBE_RETRY);
 671                 }
 672                 break;
 673
 674         case SFP_MOD_HPOWER:
 675                 if (event == SFP_E_TIMEOUT) {
 676                         sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
 677                         break;
 678                 }
 679                 /* fallthrough */
 680         case SFP_MOD_PRESENT:
 681         case SFP_MOD_ERROR:
 682                 if (event == SFP_E_REMOVE) {
 683                         sfp_sm_mod_remove(sfp);
 684                         sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
 685                 }
 686                 break;
 687         }
 688
 689         /* This state machine tracks the netdev up/down state */
 690         switch (sfp->sm_dev_state) {
 691         default:
 692                 if (event == SFP_E_DEV_UP)
 693                         sfp->sm_dev_state = SFP_DEV_UP;
 694                 break;
 695
 696         case SFP_DEV_UP:
 697                 if (event == SFP_E_DEV_DOWN) {
 698                         /* If the module has a PHY, avoid raising TX disable
 699                          * as this resets the PHY. Otherwise, raise it to
 700                          * turn the laser off.
 701                          */
 702                         if (!sfp->mod_phy)
 703                                 sfp_module_tx_disable(sfp);
 704                         sfp->sm_dev_state = SFP_DEV_DOWN;
 705                 }
 706                 break;
 707         }
 708
 709         /* Some events are global */
 710         if (sfp->sm_state != SFP_S_DOWN &&
 711             (sfp->sm_mod_state != SFP_MOD_PRESENT ||
 712              sfp->sm_dev_state != SFP_DEV_UP)) {
 713                 if (sfp->sm_state == SFP_S_LINK_UP &&
 714                     sfp->sm_dev_state == SFP_DEV_UP)
 715                         sfp_sm_link_down(sfp);
 716                 if (sfp->mod_phy)
 717                         sfp_sm_phy_detach(sfp);
 718                 sfp_sm_next(sfp, SFP_S_DOWN, 0);
 719                 mutex_unlock(&sfp->sm_mutex);
 720                 return;
 721         }
 722
 723         /* The main state machine */
 724         switch (sfp->sm_state) {
 725         case SFP_S_DOWN:
 726                 if (sfp->sm_mod_state == SFP_MOD_PRESENT &&
 727                     sfp->sm_dev_state == SFP_DEV_UP)
 728                         sfp_sm_mod_init(sfp);
 729                 break;
 730
 731         case SFP_S_INIT:
 732                 if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
 733                         sfp_sm_fault(sfp, true);
 734                 else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
 735                         sfp_sm_link_check_los(sfp);
 736                 break;
 737
 738         case SFP_S_WAIT_LOS:
 739                 if (event == SFP_E_TX_FAULT)
 740                         sfp_sm_fault(sfp, true);
 741                 else if (sfp_los_event_inactive(sfp, event))
 742                         sfp_sm_link_up(sfp);
 743                 break;
 744
 745         case SFP_S_LINK_UP:
 746                 if (event == SFP_E_TX_FAULT) {
 747                         sfp_sm_link_down(sfp);
 748                         sfp_sm_fault(sfp, true);
 749                 } else if (sfp_los_event_active(sfp, event)) {
 750                         sfp_sm_link_down(sfp);
 751                         sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
 752                 }
 753                 break;
 754
 755         case SFP_S_TX_FAULT:
 756                 if (event == SFP_E_TIMEOUT) {
 757                         sfp_module_tx_fault_reset(sfp);
 758                         sfp_sm_next(sfp, SFP_S_REINIT, T_INIT_JIFFIES);
 759                 }
 760                 break;
 761
 762         case SFP_S_REINIT:
 763                 if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
 764                         sfp_sm_fault(sfp, false);
 765                 } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
 766                         dev_info(sfp->dev, "module transmit fault recovered\n");
 767                         sfp_sm_link_check_los(sfp);
 768                 }
 769                 break;
 770
 771         case SFP_S_TX_DISABLE:
 772                 break;
 773         }
 774
 775         dev_dbg(sfp->dev, "SM: exit %u:%u:%u\n",
 776                 sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state);
 777
 778         mutex_unlock(&sfp->sm_mutex);
 779 }
 780
 781 static void sfp_start(struct sfp *sfp)
 782 {
 783         sfp_sm_event(sfp, SFP_E_DEV_UP);
 784 }
 785
 786 static void sfp_stop(struct sfp *sfp)
 787 {
 788         sfp_sm_event(sfp, SFP_E_DEV_DOWN);
 789 }
 790
 791 static int sfp_module_info(struct sfp *sfp, struct ethtool_modinfo *modinfo)
 792 {
 793         /* locking... and check module is present */
 794
 795         if (sfp->id.ext.sff8472_compliance &&
 796             !(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)) {
 797                 modinfo->type = ETH_MODULE_SFF_8472;
 798                 modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
 799         } else {
 800                 modinfo->type = ETH_MODULE_SFF_8079;
 801                 modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
 802         }
 803         return 0;
 804 }
 805
 806 static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
 807                              u8 *data)
 808 {
 809         unsigned int first, last, len;
 810         int ret;
 811
 812         if (ee->len == 0)
 813                 return -EINVAL;
 814
 815         first = ee->offset;
 816         last = ee->offset + ee->len;
 817         if (first < ETH_MODULE_SFF_8079_LEN) {
 818                 len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
 819                 len -= first;
 820
 821                 ret = sfp_read(sfp, false, first, data, len);
 822                 if (ret < 0)
 823                         return ret;
 824
 825                 first += len;
 826                 data += len;
 827         }
 828         if (first < ETH_MODULE_SFF_8472_LEN && last > ETH_MODULE_SFF_8079_LEN) {
 829                 len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
 830                 len -= first;
 831                 first -= ETH_MODULE_SFF_8079_LEN;
 832
 833                 ret = sfp_read(sfp, true, first, data, len);
 834                 if (ret < 0)
 835                         return ret;
 836         }
 837         return 0;
 838 }
 839
 840 static const struct sfp_socket_ops sfp_module_ops = {
 841         .start = sfp_start,
 842         .stop = sfp_stop,
 843         .module_info = sfp_module_info,
 844         .module_eeprom = sfp_module_eeprom,
 845 };
 846
 847 static void sfp_timeout(struct work_struct *work)
 848 {
 849         struct sfp *sfp = container_of(work, struct sfp, timeout.work);
 850
 851         rtnl_lock();
 852         sfp_sm_event(sfp, SFP_E_TIMEOUT);
 853         rtnl_unlock();
 854 }
 855
 856 static void sfp_check_state(struct sfp *sfp)
 857 {
 858         unsigned int state, i, changed;
 859
 860         state = sfp_get_state(sfp);
 861         changed = state ^ sfp->state;
 862         changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;
 863
 864         for (i = 0; i < GPIO_MAX; i++)
 865                 if (changed & BIT(i))
 866                         dev_dbg(sfp->dev, "%s %u -> %u\n", gpio_of_names[i],
 867                                 !!(sfp->state & BIT(i)), !!(state & BIT(i)));
 868
 869         state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
 870         sfp->state = state;
 871
 872         rtnl_lock();
 873         if (changed & SFP_F_PRESENT)
 874                 sfp_sm_event(sfp, state & SFP_F_PRESENT ?
 875                                 SFP_E_INSERT : SFP_E_REMOVE);
 876
 877         if (changed & SFP_F_TX_FAULT)
 878                 sfp_sm_event(sfp, state & SFP_F_TX_FAULT ?
 879                                 SFP_E_TX_FAULT : SFP_E_TX_CLEAR);
 880
 881         if (changed & SFP_F_LOS)
 882                 sfp_sm_event(sfp, state & SFP_F_LOS ?
 883                                 SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
 884         rtnl_unlock();
 885 }
 886
 887 static irqreturn_t sfp_irq(int irq, void *data)
 888 {
 889         struct sfp *sfp = data;
 890
 891         sfp_check_state(sfp);
 892
 893         return IRQ_HANDLED;
 894 }
 895
 896 static void sfp_poll(struct work_struct *work)
 897 {
 898         struct sfp *sfp = container_of(work, struct sfp, poll.work);
 899
 900         sfp_check_state(sfp);
 901         mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
 902 }
 903
 904 static struct sfp *sfp_alloc(struct device *dev)
 905 {
 906         struct sfp *sfp;
 907
 908         sfp = kzalloc(sizeof(*sfp), GFP_KERNEL);
 909         if (!sfp)
 910                 return ERR_PTR(-ENOMEM);
 911
 912         sfp->dev = dev;
 913
 914         mutex_init(&sfp->sm_mutex);
 915         INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
 916         INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);
 917
 918         return sfp;
 919 }
 920
 921 static void sfp_cleanup(void *data)
 922 {
 923         struct sfp *sfp = data;
 924
 925         cancel_delayed_work_sync(&sfp->poll);
 926         cancel_delayed_work_sync(&sfp->timeout);
 927         if (sfp->i2c_mii) {
 928                 mdiobus_unregister(sfp->i2c_mii);
 929                 mdiobus_free(sfp->i2c_mii);
 930         }
 931         if (sfp->i2c)
 932                 i2c_put_adapter(sfp->i2c);
 933         kfree(sfp);
 934 }
 935
 936 static int sfp_probe(struct platform_device *pdev)
 937 {
 938         const struct sff_data *sff;
 939         struct sfp *sfp;
 940         bool poll = false;
 941         int irq, err, i;
 942
 943         sfp = sfp_alloc(&pdev->dev);
 944         if (IS_ERR(sfp))
 945                 return PTR_ERR(sfp);
 946
 947         platform_set_drvdata(pdev, sfp);
 948
 949         err = devm_add_action(sfp->dev, sfp_cleanup, sfp);
 950         if (err < 0)
 951                 return err;
 952
 953         sff = sfp->type = &sfp_data;
 954
 955         if (pdev->dev.of_node) {
 956                 struct device_node *node = pdev->dev.of_node;
 957                 const struct of_device_id *id;
 958                 struct device_node *np;
 959
 960                 id = of_match_node(sfp_of_match, node);
 961                 if (WARN_ON(!id))
 962                         return -EINVAL;
 963
 964                 sff = sfp->type = id->data;
 965
 966                 np = of_parse_phandle(node, "i2c-bus", 0);
 967                 if (np) {
 968                         struct i2c_adapter *i2c;
 969
 970                         i2c = of_find_i2c_adapter_by_node(np);
 971                         of_node_put(np);
 972                         if (!i2c)
 973                                 return -EPROBE_DEFER;
 974
 975                         err = sfp_i2c_configure(sfp, i2c);
 976                         if (err < 0) {
 977                                 i2c_put_adapter(i2c);
 978                                 return err;
 979                         }
 980                 }
 981         }
 982
 983         for (i = 0; i < GPIO_MAX; i++)
 984                 if (sff->gpios & BIT(i)) {
 985                         sfp->gpio[i] = devm_gpiod_get_optional(sfp->dev,
 986                                            gpio_of_names[i], gpio_flags[i]);
 987                         if (IS_ERR(sfp->gpio[i]))
 988                                 return PTR_ERR(sfp->gpio[i]);
 989                 }
 990
 991         sfp->get_state = sfp_gpio_get_state;
 992         sfp->set_state = sfp_gpio_set_state;
 993
 994         /* Modules that have no detect signal are always present */
 995         if (!(sfp->gpio[GPIO_MODDEF0]))
 996                 sfp->get_state = sff_gpio_get_state;
 997
 998         device_property_read_u32(&pdev->dev, "maximum-power-milliwatt",
 999                                  &sfp->max_power_mW);
1000         if (!sfp->max_power_mW)
1001                 sfp->max_power_mW = 1000;
1002
1003         dev_info(sfp->dev, "Host maximum power %u.%uW\n",
1004                  sfp->max_power_mW / 1000, (sfp->max_power_mW / 100) % 10);
1005
1006         sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
1007         if (!sfp->sfp_bus)
1008                 return -ENOMEM;
1009
1010         /* Get the initial state, and always signal TX disable,
1011          * since the network interface will not be up.
1012          */
1013         sfp->state = sfp_get_state(sfp) | SFP_F_TX_DISABLE;
1014
1015         if (sfp->gpio[GPIO_RATE_SELECT] &&
1016             gpiod_get_value_cansleep(sfp->gpio[GPIO_RATE_SELECT]))
1017                 sfp->state |= SFP_F_RATE_SELECT;
1018         sfp_set_state(sfp, sfp->state);
1019         sfp_module_tx_disable(sfp);
1020         rtnl_lock();
1021         if (sfp->state & SFP_F_PRESENT)
1022                 sfp_sm_event(sfp, SFP_E_INSERT);
1023         rtnl_unlock();
1024
1025         for (i = 0; i < GPIO_MAX; i++) {
1026                 if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
1027                         continue;
1028
1029                 irq = gpiod_to_irq(sfp->gpio[i]);
1030                 if (!irq) {
1031                         poll = true;
1032                         continue;
1033                 }
1034
1035                 err = devm_request_threaded_irq(sfp->dev, irq, NULL, sfp_irq,
1036                                                 IRQF_ONESHOT |
1037                                                 IRQF_TRIGGER_RISING |
1038                                                 IRQF_TRIGGER_FALLING,
1039                                                 dev_name(sfp->dev), sfp);
1040                 if (err)
1041                         poll = true;
1042         }
1043
1044         if (poll)
1045                 mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
1046
1047         return 0;
1048 }
1049
1050 static int sfp_remove(struct platform_device *pdev)
1051 {
1052         struct sfp *sfp = platform_get_drvdata(pdev);
1053
1054         sfp_unregister_socket(sfp->sfp_bus);
1055
1056         return 0;
1057 }
1058
1059 static struct platform_driver sfp_driver = {
1060         .probe = sfp_probe,
1061         .remove = sfp_remove,
1062         .driver = {
1063                 .name = "sfp",
1064                 .of_match_table = sfp_of_match,
1065         },
1066 };
1067
1068 static int sfp_init(void)
1069 {
1070         poll_jiffies = msecs_to_jiffies(100);
1071
1072         return platform_driver_register(&sfp_driver);
1073 }
1074 module_init(sfp_init);
1075
1076 static void sfp_exit(void)
1077 {
1078         platform_driver_unregister(&sfp_driver);
1079 }
1080 module_exit(sfp_exit);
1081
1082 MODULE_ALIAS("platform:sfp");
1083 MODULE_AUTHOR("Russell King");
1084 MODULE_LICENSE("GPL v2");