linux/drivers/net/phy/sfp.c
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   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
  19enum {
  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
  61static const char *gpio_of_names[] = {
  62        "mod-def0",
  63        "los",
  64        "tx-fault",
  65        "tx-disable",
  66        "rate-select0",
  67};
  68
  69static 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
 101static DEFINE_MUTEX(sfp_mutex);
 102
 103struct sff_data {
 104        unsigned int gpios;
 105        bool (*module_supported)(const struct sfp_eeprom_id *id);
 106};
 107
 108struct 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
 136static 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
 142static 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
 147static 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
 153static 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
 159static const struct of_device_id sfp_of_match[] = {
 160        { .compatible = "sff,sff", .data = &sff_data, },
 161        { .compatible = "sff,sfp", .data = &sfp_data, },
 162        { },
 163};
 164MODULE_DEVICE_TABLE(of, sfp_of_match);
 165
 166static unsigned long poll_jiffies;
 167
 168static 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
 184static unsigned int sff_gpio_get_state(struct sfp *sfp)
 185{
 186        return sfp_gpio_get_state(sfp) | SFP_F_PRESENT;
 187}
 188
 189static 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
 208static 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
 231static 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
 258static 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 */
 289static unsigned int sfp_get_state(struct sfp *sfp)
 290{
 291        return sfp->get_state(sfp);
 292}
 293
 294static void sfp_set_state(struct sfp *sfp, unsigned int state)
 295{
 296        sfp->set_state(sfp, state);
 297}
 298
 299static 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
 304static 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
 309static 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 */
 320static 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
 328static 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
 336static 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 */
 351static 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
 360static 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
 367static 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
 374static 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
 383static 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
 412static 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
 418static void sfp_sm_link_down(struct sfp *sfp)
 419{
 420        sfp_link_down(sfp->sfp_bus);
 421}
 422
 423static 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
 441static 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
 449static 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
 457static 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
 471static 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
 497static 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
 555err:
 556        return err;
 557}
 558
 559static int sfp_sm_mod_probe(struct sfp *sfp)
 560{
 561        /* SFP module inserted - read I2C data */
 562        struct sfp_eeprom_id id;
 563        bool cotsworks;
 564        u8 check;
 565        int ret;
 566
 567        ret = sfp_read(sfp, false, 0, &id, sizeof(id));
 568        if (ret < 0) {
 569                dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
 570                return -EAGAIN;
 571        }
 572
 573        if (ret != sizeof(id)) {
 574                dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
 575                return -EAGAIN;
 576        }
 577
 578        /* Cotsworks do not seem to update the checksums when they
 579         * do the final programming with the final module part number,
 580         * serial number and date code.
 581         */
 582        cotsworks = !memcmp(id.base.vendor_name, "COTSWORKS       ", 16);
 583
 584        /* Validate the checksum over the base structure */
 585        check = sfp_check(&id.base, sizeof(id.base) - 1);
 586        if (check != id.base.cc_base) {
 587                if (cotsworks) {
 588                        dev_warn(sfp->dev,
 589                                 "EEPROM base structure checksum failure (0x%02x != 0x%02x)\n",
 590                                 check, id.base.cc_base);
 591                } else {
 592                        dev_err(sfp->dev,
 593                                "EEPROM base structure checksum failure: 0x%02x != 0x%02x\n",
 594                                check, id.base.cc_base);
 595                        print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
 596                                       16, 1, &id, sizeof(id), true);
 597                        return -EINVAL;
 598                }
 599        }
 600
 601        check = sfp_check(&id.ext, sizeof(id.ext) - 1);
 602        if (check != id.ext.cc_ext) {
 603                if (cotsworks) {
 604                        dev_warn(sfp->dev,
 605                                 "EEPROM extended structure checksum failure (0x%02x != 0x%02x)\n",
 606                                 check, id.ext.cc_ext);
 607                } else {
 608                        dev_err(sfp->dev,
 609                                "EEPROM extended structure checksum failure: 0x%02x != 0x%02x\n",
 610                                check, id.ext.cc_ext);
 611                        print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
 612                                       16, 1, &id, sizeof(id), true);
 613                        memset(&id.ext, 0, sizeof(id.ext));
 614                }
 615        }
 616
 617        sfp->id = id;
 618
 619        dev_info(sfp->dev, "module %.*s %.*s rev %.*s sn %.*s dc %.*s\n",
 620                 (int)sizeof(id.base.vendor_name), id.base.vendor_name,
 621                 (int)sizeof(id.base.vendor_pn), id.base.vendor_pn,
 622                 (int)sizeof(id.base.vendor_rev), id.base.vendor_rev,
 623                 (int)sizeof(id.ext.vendor_sn), id.ext.vendor_sn,
 624                 (int)sizeof(id.ext.datecode), id.ext.datecode);
 625
 626        /* Check whether we support this module */
 627        if (!sfp->type->module_supported(&sfp->id)) {
 628                dev_err(sfp->dev,
 629                        "module is not supported - phys id 0x%02x 0x%02x\n",
 630                        sfp->id.base.phys_id, sfp->id.base.phys_ext_id);
 631                return -EINVAL;
 632        }
 633
 634        /* If the module requires address swap mode, warn about it */
 635        if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
 636                dev_warn(sfp->dev,
 637                         "module address swap to access page 0xA2 is not supported.\n");
 638
 639        ret = sfp_module_insert(sfp->sfp_bus, &sfp->id);
 640        if (ret < 0)
 641                return ret;
 642
 643        return sfp_sm_mod_hpower(sfp);
 644}
 645
 646static void sfp_sm_mod_remove(struct sfp *sfp)
 647{
 648        sfp_module_remove(sfp->sfp_bus);
 649
 650        if (sfp->mod_phy)
 651                sfp_sm_phy_detach(sfp);
 652
 653        sfp_module_tx_disable(sfp);
 654
 655        memset(&sfp->id, 0, sizeof(sfp->id));
 656
 657        dev_info(sfp->dev, "module removed\n");
 658}
 659
 660static void sfp_sm_event(struct sfp *sfp, unsigned int event)
 661{
 662        mutex_lock(&sfp->sm_mutex);
 663
 664        dev_dbg(sfp->dev, "SM: enter %u:%u:%u event %u\n",
 665                sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state, event);
 666
 667        /* This state machine tracks the insert/remove state of
 668         * the module, and handles probing the on-board EEPROM.
 669         */
 670        switch (sfp->sm_mod_state) {
 671        default:
 672                if (event == SFP_E_INSERT) {
 673                        sfp_module_tx_disable(sfp);
 674                        sfp_sm_ins_next(sfp, SFP_MOD_PROBE, T_PROBE_INIT);
 675                }
 676                break;
 677
 678        case SFP_MOD_PROBE:
 679                if (event == SFP_E_REMOVE) {
 680                        sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
 681                } else if (event == SFP_E_TIMEOUT) {
 682                        int val = sfp_sm_mod_probe(sfp);
 683
 684                        if (val == 0)
 685                                sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
 686                        else if (val > 0)
 687                                sfp_sm_ins_next(sfp, SFP_MOD_HPOWER, val);
 688                        else if (val != -EAGAIN)
 689                                sfp_sm_ins_next(sfp, SFP_MOD_ERROR, 0);
 690                        else
 691                                sfp_sm_set_timer(sfp, T_PROBE_RETRY);
 692                }
 693                break;
 694
 695        case SFP_MOD_HPOWER:
 696                if (event == SFP_E_TIMEOUT) {
 697                        sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
 698                        break;
 699                }
 700                /* fallthrough */
 701        case SFP_MOD_PRESENT:
 702        case SFP_MOD_ERROR:
 703                if (event == SFP_E_REMOVE) {
 704                        sfp_sm_mod_remove(sfp);
 705                        sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
 706                }
 707                break;
 708        }
 709
 710        /* This state machine tracks the netdev up/down state */
 711        switch (sfp->sm_dev_state) {
 712        default:
 713                if (event == SFP_E_DEV_UP)
 714                        sfp->sm_dev_state = SFP_DEV_UP;
 715                break;
 716
 717        case SFP_DEV_UP:
 718                if (event == SFP_E_DEV_DOWN) {
 719                        /* If the module has a PHY, avoid raising TX disable
 720                         * as this resets the PHY. Otherwise, raise it to
 721                         * turn the laser off.
 722                         */
 723                        if (!sfp->mod_phy)
 724                                sfp_module_tx_disable(sfp);
 725                        sfp->sm_dev_state = SFP_DEV_DOWN;
 726                }
 727                break;
 728        }
 729
 730        /* Some events are global */
 731        if (sfp->sm_state != SFP_S_DOWN &&
 732            (sfp->sm_mod_state != SFP_MOD_PRESENT ||
 733             sfp->sm_dev_state != SFP_DEV_UP)) {
 734                if (sfp->sm_state == SFP_S_LINK_UP &&
 735                    sfp->sm_dev_state == SFP_DEV_UP)
 736                        sfp_sm_link_down(sfp);
 737                if (sfp->mod_phy)
 738                        sfp_sm_phy_detach(sfp);
 739                sfp_sm_next(sfp, SFP_S_DOWN, 0);
 740                mutex_unlock(&sfp->sm_mutex);
 741                return;
 742        }
 743
 744        /* The main state machine */
 745        switch (sfp->sm_state) {
 746        case SFP_S_DOWN:
 747                if (sfp->sm_mod_state == SFP_MOD_PRESENT &&
 748                    sfp->sm_dev_state == SFP_DEV_UP)
 749                        sfp_sm_mod_init(sfp);
 750                break;
 751
 752        case SFP_S_INIT:
 753                if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
 754                        sfp_sm_fault(sfp, true);
 755                else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
 756                        sfp_sm_link_check_los(sfp);
 757                break;
 758
 759        case SFP_S_WAIT_LOS:
 760                if (event == SFP_E_TX_FAULT)
 761                        sfp_sm_fault(sfp, true);
 762                else if (sfp_los_event_inactive(sfp, event))
 763                        sfp_sm_link_up(sfp);
 764                break;
 765
 766        case SFP_S_LINK_UP:
 767                if (event == SFP_E_TX_FAULT) {
 768                        sfp_sm_link_down(sfp);
 769                        sfp_sm_fault(sfp, true);
 770                } else if (sfp_los_event_active(sfp, event)) {
 771                        sfp_sm_link_down(sfp);
 772                        sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
 773                }
 774                break;
 775
 776        case SFP_S_TX_FAULT:
 777                if (event == SFP_E_TIMEOUT) {
 778                        sfp_module_tx_fault_reset(sfp);
 779                        sfp_sm_next(sfp, SFP_S_REINIT, T_INIT_JIFFIES);
 780                }
 781                break;
 782
 783        case SFP_S_REINIT:
 784                if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
 785                        sfp_sm_fault(sfp, false);
 786                } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
 787                        dev_info(sfp->dev, "module transmit fault recovered\n");
 788                        sfp_sm_link_check_los(sfp);
 789                }
 790                break;
 791
 792        case SFP_S_TX_DISABLE:
 793                break;
 794        }
 795
 796        dev_dbg(sfp->dev, "SM: exit %u:%u:%u\n",
 797                sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state);
 798
 799        mutex_unlock(&sfp->sm_mutex);
 800}
 801
 802static void sfp_start(struct sfp *sfp)
 803{
 804        sfp_sm_event(sfp, SFP_E_DEV_UP);
 805}
 806
 807static void sfp_stop(struct sfp *sfp)
 808{
 809        sfp_sm_event(sfp, SFP_E_DEV_DOWN);
 810}
 811
 812static int sfp_module_info(struct sfp *sfp, struct ethtool_modinfo *modinfo)
 813{
 814        /* locking... and check module is present */
 815
 816        if (sfp->id.ext.sff8472_compliance &&
 817            !(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)) {
 818                modinfo->type = ETH_MODULE_SFF_8472;
 819                modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
 820        } else {
 821                modinfo->type = ETH_MODULE_SFF_8079;
 822                modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
 823        }
 824        return 0;
 825}
 826
 827static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
 828                             u8 *data)
 829{
 830        unsigned int first, last, len;
 831        int ret;
 832
 833        if (ee->len == 0)
 834                return -EINVAL;
 835
 836        first = ee->offset;
 837        last = ee->offset + ee->len;
 838        if (first < ETH_MODULE_SFF_8079_LEN) {
 839                len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
 840                len -= first;
 841
 842                ret = sfp_read(sfp, false, first, data, len);
 843                if (ret < 0)
 844                        return ret;
 845
 846                first += len;
 847                data += len;
 848        }
 849        if (first < ETH_MODULE_SFF_8472_LEN && last > ETH_MODULE_SFF_8079_LEN) {
 850                len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
 851                len -= first;
 852                first -= ETH_MODULE_SFF_8079_LEN;
 853
 854                ret = sfp_read(sfp, true, first, data, len);
 855                if (ret < 0)
 856                        return ret;
 857        }
 858        return 0;
 859}
 860
 861static const struct sfp_socket_ops sfp_module_ops = {
 862        .start = sfp_start,
 863        .stop = sfp_stop,
 864        .module_info = sfp_module_info,
 865        .module_eeprom = sfp_module_eeprom,
 866};
 867
 868static void sfp_timeout(struct work_struct *work)
 869{
 870        struct sfp *sfp = container_of(work, struct sfp, timeout.work);
 871
 872        rtnl_lock();
 873        sfp_sm_event(sfp, SFP_E_TIMEOUT);
 874        rtnl_unlock();
 875}
 876
 877static void sfp_check_state(struct sfp *sfp)
 878{
 879        unsigned int state, i, changed;
 880
 881        state = sfp_get_state(sfp);
 882        changed = state ^ sfp->state;
 883        changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;
 884
 885        for (i = 0; i < GPIO_MAX; i++)
 886                if (changed & BIT(i))
 887                        dev_dbg(sfp->dev, "%s %u -> %u\n", gpio_of_names[i],
 888                                !!(sfp->state & BIT(i)), !!(state & BIT(i)));
 889
 890        state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
 891        sfp->state = state;
 892
 893        rtnl_lock();
 894        if (changed & SFP_F_PRESENT)
 895                sfp_sm_event(sfp, state & SFP_F_PRESENT ?
 896                                SFP_E_INSERT : SFP_E_REMOVE);
 897
 898        if (changed & SFP_F_TX_FAULT)
 899                sfp_sm_event(sfp, state & SFP_F_TX_FAULT ?
 900                                SFP_E_TX_FAULT : SFP_E_TX_CLEAR);
 901
 902        if (changed & SFP_F_LOS)
 903                sfp_sm_event(sfp, state & SFP_F_LOS ?
 904                                SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
 905        rtnl_unlock();
 906}
 907
 908static irqreturn_t sfp_irq(int irq, void *data)
 909{
 910        struct sfp *sfp = data;
 911
 912        sfp_check_state(sfp);
 913
 914        return IRQ_HANDLED;
 915}
 916
 917static void sfp_poll(struct work_struct *work)
 918{
 919        struct sfp *sfp = container_of(work, struct sfp, poll.work);
 920
 921        sfp_check_state(sfp);
 922        mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
 923}
 924
 925static struct sfp *sfp_alloc(struct device *dev)
 926{
 927        struct sfp *sfp;
 928
 929        sfp = kzalloc(sizeof(*sfp), GFP_KERNEL);
 930        if (!sfp)
 931                return ERR_PTR(-ENOMEM);
 932
 933        sfp->dev = dev;
 934
 935        mutex_init(&sfp->sm_mutex);
 936        INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
 937        INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);
 938
 939        return sfp;
 940}
 941
 942static void sfp_cleanup(void *data)
 943{
 944        struct sfp *sfp = data;
 945
 946        cancel_delayed_work_sync(&sfp->poll);
 947        cancel_delayed_work_sync(&sfp->timeout);
 948        if (sfp->i2c_mii) {
 949                mdiobus_unregister(sfp->i2c_mii);
 950                mdiobus_free(sfp->i2c_mii);
 951        }
 952        if (sfp->i2c)
 953                i2c_put_adapter(sfp->i2c);
 954        kfree(sfp);
 955}
 956
 957static int sfp_probe(struct platform_device *pdev)
 958{
 959        const struct sff_data *sff;
 960        struct sfp *sfp;
 961        bool poll = false;
 962        int irq, err, i;
 963
 964        sfp = sfp_alloc(&pdev->dev);
 965        if (IS_ERR(sfp))
 966                return PTR_ERR(sfp);
 967
 968        platform_set_drvdata(pdev, sfp);
 969
 970        err = devm_add_action(sfp->dev, sfp_cleanup, sfp);
 971        if (err < 0)
 972                return err;
 973
 974        sff = sfp->type = &sfp_data;
 975
 976        if (pdev->dev.of_node) {
 977                struct device_node *node = pdev->dev.of_node;
 978                const struct of_device_id *id;
 979                struct i2c_adapter *i2c;
 980                struct device_node *np;
 981
 982                id = of_match_node(sfp_of_match, node);
 983                if (WARN_ON(!id))
 984                        return -EINVAL;
 985
 986                sff = sfp->type = id->data;
 987
 988                np = of_parse_phandle(node, "i2c-bus", 0);
 989                if (!np) {
 990                        dev_err(sfp->dev, "missing 'i2c-bus' property\n");
 991                        return -ENODEV;
 992                }
 993
 994                i2c = of_find_i2c_adapter_by_node(np);
 995                of_node_put(np);
 996                if (!i2c)
 997                        return -EPROBE_DEFER;
 998
 999                err = sfp_i2c_configure(sfp, i2c);
1000                if (err < 0) {
1001                        i2c_put_adapter(i2c);
1002                        return err;
1003                }
1004        }
1005
1006        for (i = 0; i < GPIO_MAX; i++)
1007                if (sff->gpios & BIT(i)) {
1008                        sfp->gpio[i] = devm_gpiod_get_optional(sfp->dev,
1009                                           gpio_of_names[i], gpio_flags[i]);
1010                        if (IS_ERR(sfp->gpio[i]))
1011                                return PTR_ERR(sfp->gpio[i]);
1012                }
1013
1014        sfp->get_state = sfp_gpio_get_state;
1015        sfp->set_state = sfp_gpio_set_state;
1016
1017        /* Modules that have no detect signal are always present */
1018        if (!(sfp->gpio[GPIO_MODDEF0]))
1019                sfp->get_state = sff_gpio_get_state;
1020
1021        device_property_read_u32(&pdev->dev, "maximum-power-milliwatt",
1022                                 &sfp->max_power_mW);
1023        if (!sfp->max_power_mW)
1024                sfp->max_power_mW = 1000;
1025
1026        dev_info(sfp->dev, "Host maximum power %u.%uW\n",
1027                 sfp->max_power_mW / 1000, (sfp->max_power_mW / 100) % 10);
1028
1029        sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
1030        if (!sfp->sfp_bus)
1031                return -ENOMEM;
1032
1033        /* Get the initial state, and always signal TX disable,
1034         * since the network interface will not be up.
1035         */
1036        sfp->state = sfp_get_state(sfp) | SFP_F_TX_DISABLE;
1037
1038        if (sfp->gpio[GPIO_RATE_SELECT] &&
1039            gpiod_get_value_cansleep(sfp->gpio[GPIO_RATE_SELECT]))
1040                sfp->state |= SFP_F_RATE_SELECT;
1041        sfp_set_state(sfp, sfp->state);
1042        sfp_module_tx_disable(sfp);
1043        rtnl_lock();
1044        if (sfp->state & SFP_F_PRESENT)
1045                sfp_sm_event(sfp, SFP_E_INSERT);
1046        rtnl_unlock();
1047
1048        for (i = 0; i < GPIO_MAX; i++) {
1049                if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
1050                        continue;
1051
1052                irq = gpiod_to_irq(sfp->gpio[i]);
1053                if (!irq) {
1054                        poll = true;
1055                        continue;
1056                }
1057
1058                err = devm_request_threaded_irq(sfp->dev, irq, NULL, sfp_irq,
1059                                                IRQF_ONESHOT |
1060                                                IRQF_TRIGGER_RISING |
1061                                                IRQF_TRIGGER_FALLING,
1062                                                dev_name(sfp->dev), sfp);
1063                if (err)
1064                        poll = true;
1065        }
1066
1067        if (poll)
1068                mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
1069
1070        /* We could have an issue in cases no Tx disable pin is available or
1071         * wired as modules using a laser as their light source will continue to
1072         * be active when the fiber is removed. This could be a safety issue and
1073         * we should at least warn the user about that.
1074         */
1075        if (!sfp->gpio[GPIO_TX_DISABLE])
1076                dev_warn(sfp->dev,
1077                         "No tx_disable pin: SFP modules will always be emitting.\n");
1078
1079        return 0;
1080}
1081
1082static int sfp_remove(struct platform_device *pdev)
1083{
1084        struct sfp *sfp = platform_get_drvdata(pdev);
1085
1086        sfp_unregister_socket(sfp->sfp_bus);
1087
1088        return 0;
1089}
1090
1091static struct platform_driver sfp_driver = {
1092        .probe = sfp_probe,
1093        .remove = sfp_remove,
1094        .driver = {
1095                .name = "sfp",
1096                .of_match_table = sfp_of_match,
1097        },
1098};
1099
1100static int sfp_init(void)
1101{
1102        poll_jiffies = msecs_to_jiffies(100);
1103
1104        return platform_driver_register(&sfp_driver);
1105}
1106module_init(sfp_init);
1107
1108static void sfp_exit(void)
1109{
1110        platform_driver_unregister(&sfp_driver);
1111}
1112module_exit(sfp_exit);
1113
1114MODULE_ALIAS("platform:sfp");
1115MODULE_AUTHOR("Russell King");
1116MODULE_LICENSE("GPL v2");
1117