linux/drivers/leds/leds-tca6507.c
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   1/*
   2 * leds-tca6507
   3 *
   4 * The TCA6507 is a programmable LED controller that can drive 7
   5 * separate lines either by holding them low, or by pulsing them
   6 * with modulated width.
   7 * The modulation can be varied in a simple pattern to produce a blink or
   8 * double-blink.
   9 *
  10 * This driver can configure each line either as a 'GPIO' which is out-only
  11 * (no pull-up) or as an LED with variable brightness and hardware-assisted
  12 * blinking.
  13 *
  14 * Apart from OFF and ON there are three programmable brightness levels which
  15 * can be programmed from 0 to 15 and indicate how many 500usec intervals in
  16 * each 8msec that the led is 'on'.  The levels are named MASTER, BANK0 and
  17 * BANK1.
  18 *
  19 * There are two different blink rates that can be programmed, each with
  20 * separate time for rise, on, fall, off and second-off.  Thus if 3 or more
  21 * different non-trivial rates are required, software must be used for the extra
  22 * rates. The two different blink rates must align with the two levels BANK0 and
  23 * BANK1.
  24 * This driver does not support double-blink so 'second-off' always matches
  25 * 'off'.
  26 *
  27 * Only 16 different times can be programmed in a roughly logarithmic scale from
  28 * 64ms to 16320ms.  To be precise the possible times are:
  29 *    0, 64, 128, 192, 256, 384, 512, 768,
  30 *    1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
  31 *
  32 * Times that cannot be closely matched with these must be
  33 * handled in software.  This driver allows 12.5% error in matching.
  34 *
  35 * This driver does not allow rise/fall rates to be set explicitly.  When trying
  36 * to match a given 'on' or 'off' period, an appropriate pair of 'change' and
  37 * 'hold' times are chosen to get a close match.  If the target delay is even,
  38 * the 'change' number will be the smaller; if odd, the 'hold' number will be
  39 * the smaller.
  40
  41 * Choosing pairs of delays with 12.5% errors allows us to match delays in the
  42 * ranges: 56-72, 112-144, 168-216, 224-27504, 28560-36720.
  43 * 26% of the achievable sums can be matched by multiple pairings. For example
  44 * 1536 == 1536+0, 1024+512, or 768+768.  This driver will always choose the
  45 * pairing with the least maximum - 768+768 in this case.  Other pairings are
  46 * not available.
  47 *
  48 * Access to the 3 levels and 2 blinks are on a first-come, first-served basis.
  49 * Access can be shared by multiple leds if they have the same level and
  50 * either same blink rates, or some don't blink.
  51 * When a led changes, it relinquishes access and tries again, so it might
  52 * lose access to hardware blink.
  53 * If a blink engine cannot be allocated, software blink is used.
  54 * If the desired brightness cannot be allocated, the closest available non-zero
  55 * brightness is used.  As 'full' is always available, the worst case would be
  56 * to have two different blink rates at '1', with Max at '2', then other leds
  57 * will have to choose between '2' and '16'.  Hopefully this is not likely.
  58 *
  59 * Each bank (BANK0 and BANK1) has two usage counts - LEDs using the brightness
  60 * and LEDs using the blink.  It can only be reprogrammed when the appropriate
  61 * counter is zero.  The MASTER level has a single usage count.
  62 *
  63 * Each Led has programmable 'on' and 'off' time as milliseconds.  With each
  64 * there is a flag saying if it was explicitly requested or defaulted.
  65 * Similarly the banks know if each time was explicit or a default.  Defaults
  66 * are permitted to be changed freely - they are not recognised when matching.
  67 *
  68 *
  69 * An led-tca6507 device must be provided with platform data.  This data
  70 * lists for each output: the name, default trigger, and whether the signal
  71 * is being used as a GPiO rather than an led.  'struct led_plaform_data'
  72 * is used for this.  If 'name' is NULL, the output isn't used.  If 'flags'
  73 * is TCA6507_MAKE_CPIO, the output is a GPO.
  74 * The "struct led_platform_data" can be embedded in a
  75 * "struct tca6507_platform_data" which adds a 'gpio_base' for the GPiOs,
  76 * and a 'setup' callback which is called once the GPiOs are available.
  77 *
  78 */
  79
  80#include <linux/module.h>
  81#include <linux/slab.h>
  82#include <linux/leds.h>
  83#include <linux/err.h>
  84#include <linux/i2c.h>
  85#include <linux/gpio.h>
  86#include <linux/workqueue.h>
  87#include <linux/leds-tca6507.h>
  88#include <linux/of.h>
  89
  90/* LED select registers determine the source that drives LED outputs */
  91#define TCA6507_LS_LED_OFF      0x0     /* Output HI-Z (off) */
  92#define TCA6507_LS_LED_OFF1     0x1     /* Output HI-Z (off) - not used */
  93#define TCA6507_LS_LED_PWM0     0x2     /* Output LOW with Bank0 rate */
  94#define TCA6507_LS_LED_PWM1     0x3     /* Output LOW with Bank1 rate */
  95#define TCA6507_LS_LED_ON       0x4     /* Output LOW (on) */
  96#define TCA6507_LS_LED_MIR      0x5     /* Output LOW with Master Intensity */
  97#define TCA6507_LS_BLINK0       0x6     /* Blink at Bank0 rate */
  98#define TCA6507_LS_BLINK1       0x7     /* Blink at Bank1 rate */
  99
 100enum {
 101        BANK0,
 102        BANK1,
 103        MASTER,
 104};
 105static int bank_source[3] = {
 106        TCA6507_LS_LED_PWM0,
 107        TCA6507_LS_LED_PWM1,
 108        TCA6507_LS_LED_MIR,
 109};
 110static int blink_source[2] = {
 111        TCA6507_LS_BLINK0,
 112        TCA6507_LS_BLINK1,
 113};
 114
 115/* PWM registers */
 116#define TCA6507_REG_CNT                 11
 117
 118/*
 119 * 0x00, 0x01, 0x02 encode the TCA6507_LS_* values, each output
 120 * owns one bit in each register
 121 */
 122#define TCA6507_FADE_ON                 0x03
 123#define TCA6507_FULL_ON                 0x04
 124#define TCA6507_FADE_OFF                0x05
 125#define TCA6507_FIRST_OFF               0x06
 126#define TCA6507_SECOND_OFF              0x07
 127#define TCA6507_MAX_INTENSITY           0x08
 128#define TCA6507_MASTER_INTENSITY        0x09
 129#define TCA6507_INITIALIZE              0x0A
 130
 131#define INIT_CODE                       0x8
 132
 133#define TIMECODES 16
 134static int time_codes[TIMECODES] = {
 135        0, 64, 128, 192, 256, 384, 512, 768,
 136        1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
 137};
 138
 139/* Convert an led.brightness level (0..255) to a TCA6507 level (0..15) */
 140static inline int TO_LEVEL(int brightness)
 141{
 142        return brightness >> 4;
 143}
 144
 145/* ...and convert back */
 146static inline int TO_BRIGHT(int level)
 147{
 148        if (level)
 149                return (level << 4) | 0xf;
 150        return 0;
 151}
 152
 153#define NUM_LEDS 7
 154struct tca6507_chip {
 155        int                     reg_set;        /* One bit per register where
 156                                                 * a '1' means the register
 157                                                 * should be written */
 158        u8                      reg_file[TCA6507_REG_CNT];
 159        /* Bank 2 is Master Intensity and doesn't use times */
 160        struct bank {
 161                int level;
 162                int ontime, offtime;
 163                int on_dflt, off_dflt;
 164                int time_use, level_use;
 165        } bank[3];
 166        struct i2c_client       *client;
 167        struct work_struct      work;
 168        spinlock_t              lock;
 169
 170        struct tca6507_led {
 171                struct tca6507_chip     *chip;
 172                struct led_classdev     led_cdev;
 173                int                     num;
 174                int                     ontime, offtime;
 175                int                     on_dflt, off_dflt;
 176                int                     bank;   /* Bank used, or -1 */
 177                int                     blink;  /* Set if hardware-blinking */
 178        } leds[NUM_LEDS];
 179#ifdef CONFIG_GPIOLIB
 180        struct gpio_chip                gpio;
 181        const char                      *gpio_name[NUM_LEDS];
 182        int                             gpio_map[NUM_LEDS];
 183#endif
 184};
 185
 186static const struct i2c_device_id tca6507_id[] = {
 187        { "tca6507" },
 188        { }
 189};
 190MODULE_DEVICE_TABLE(i2c, tca6507_id);
 191
 192static int choose_times(int msec, int *c1p, int *c2p)
 193{
 194        /*
 195         * Choose two timecodes which add to 'msec' as near as possible.
 196         * The first returned is the 'on' or 'off' time.  The second is to be
 197         * used as a 'fade-on' or 'fade-off' time.  If 'msec' is even,
 198         * the first will not be smaller than the second.  If 'msec' is odd,
 199         * the first will not be larger than the second.
 200         * If we cannot get a sum within 1/8 of 'msec' fail with -EINVAL,
 201         * otherwise return the sum that was achieved, plus 1 if the first is
 202         * smaller.
 203         * If two possibilities are equally good (e.g. 512+0, 256+256), choose
 204         * the first pair so there is more change-time visible (i.e. it is
 205         * softer).
 206         */
 207        int c1, c2;
 208        int tmax = msec * 9 / 8;
 209        int tmin = msec * 7 / 8;
 210        int diff = 65536;
 211
 212        /* We start at '1' to ensure we never even think of choosing a
 213         * total time of '0'.
 214         */
 215        for (c1 = 1; c1 < TIMECODES; c1++) {
 216                int t = time_codes[c1];
 217                if (t*2 < tmin)
 218                        continue;
 219                if (t > tmax)
 220                        break;
 221                for (c2 = 0; c2 <= c1; c2++) {
 222                        int tt = t + time_codes[c2];
 223                        int d;
 224                        if (tt < tmin)
 225                                continue;
 226                        if (tt > tmax)
 227                                break;
 228                        /* This works! */
 229                        d = abs(msec - tt);
 230                        if (d >= diff)
 231                                continue;
 232                        /* Best yet */
 233                        *c1p = c1;
 234                        *c2p = c2;
 235                        diff = d;
 236                        if (d == 0)
 237                                return msec;
 238                }
 239        }
 240        if (diff < 65536) {
 241                int actual;
 242                if (msec & 1) {
 243                        c1 = *c2p;
 244                        *c2p = *c1p;
 245                        *c1p = c1;
 246                }
 247                actual = time_codes[*c1p] + time_codes[*c2p];
 248                if (*c1p < *c2p)
 249                        return actual + 1;
 250                else
 251                        return actual;
 252        }
 253        /* No close match */
 254        return -EINVAL;
 255}
 256
 257/*
 258 * Update the register file with the appropriate 3-bit state for
 259 * the given led.
 260 */
 261static void set_select(struct tca6507_chip *tca, int led, int val)
 262{
 263        int mask = (1 << led);
 264        int bit;
 265
 266        for (bit = 0; bit < 3; bit++) {
 267                int n = tca->reg_file[bit] & ~mask;
 268                if (val & (1 << bit))
 269                        n |= mask;
 270                if (tca->reg_file[bit] != n) {
 271                        tca->reg_file[bit] = n;
 272                        tca->reg_set |= (1 << bit);
 273                }
 274        }
 275}
 276
 277/* Update the register file with the appropriate 4-bit code for
 278 * one bank or other.  This can be used for timers, for levels, or
 279 * for initialisation.
 280 */
 281static void set_code(struct tca6507_chip *tca, int reg, int bank, int new)
 282{
 283        int mask = 0xF;
 284        int n;
 285        if (bank) {
 286                mask <<= 4;
 287                new <<= 4;
 288        }
 289        n = tca->reg_file[reg] & ~mask;
 290        n |= new;
 291        if (tca->reg_file[reg] != n) {
 292                tca->reg_file[reg] = n;
 293                tca->reg_set |= 1 << reg;
 294        }
 295}
 296
 297/* Update brightness level. */
 298static void set_level(struct tca6507_chip *tca, int bank, int level)
 299{
 300        switch (bank) {
 301        case BANK0:
 302        case BANK1:
 303                set_code(tca, TCA6507_MAX_INTENSITY, bank, level);
 304                break;
 305        case MASTER:
 306                set_code(tca, TCA6507_MASTER_INTENSITY, 0, level);
 307                break;
 308        }
 309        tca->bank[bank].level = level;
 310}
 311
 312/* Record all relevant time code for a given bank */
 313static void set_times(struct tca6507_chip *tca, int bank)
 314{
 315        int c1, c2;
 316        int result;
 317
 318        result = choose_times(tca->bank[bank].ontime, &c1, &c2);
 319        dev_dbg(&tca->client->dev,
 320                "Chose on  times %d(%d) %d(%d) for %dms\n", c1, time_codes[c1],
 321                c2, time_codes[c2], tca->bank[bank].ontime);
 322        set_code(tca, TCA6507_FADE_ON, bank, c2);
 323        set_code(tca, TCA6507_FULL_ON, bank, c1);
 324        tca->bank[bank].ontime = result;
 325
 326        result = choose_times(tca->bank[bank].offtime, &c1, &c2);
 327        dev_dbg(&tca->client->dev,
 328                "Chose off times %d(%d) %d(%d) for %dms\n", c1, time_codes[c1],
 329                c2, time_codes[c2], tca->bank[bank].offtime);
 330        set_code(tca, TCA6507_FADE_OFF, bank, c2);
 331        set_code(tca, TCA6507_FIRST_OFF, bank, c1);
 332        set_code(tca, TCA6507_SECOND_OFF, bank, c1);
 333        tca->bank[bank].offtime = result;
 334
 335        set_code(tca, TCA6507_INITIALIZE, bank, INIT_CODE);
 336}
 337
 338/* Write all needed register of tca6507 */
 339
 340static void tca6507_work(struct work_struct *work)
 341{
 342        struct tca6507_chip *tca = container_of(work, struct tca6507_chip,
 343                                                work);
 344        struct i2c_client *cl = tca->client;
 345        int set;
 346        u8 file[TCA6507_REG_CNT];
 347        int r;
 348
 349        spin_lock_irq(&tca->lock);
 350        set = tca->reg_set;
 351        memcpy(file, tca->reg_file, TCA6507_REG_CNT);
 352        tca->reg_set = 0;
 353        spin_unlock_irq(&tca->lock);
 354
 355        for (r = 0; r < TCA6507_REG_CNT; r++)
 356                if (set & (1<<r))
 357                        i2c_smbus_write_byte_data(cl, r, file[r]);
 358}
 359
 360static void led_release(struct tca6507_led *led)
 361{
 362        /* If led owns any resource, release it. */
 363        struct tca6507_chip *tca = led->chip;
 364        if (led->bank >= 0) {
 365                struct bank *b = tca->bank + led->bank;
 366                if (led->blink)
 367                        b->time_use--;
 368                b->level_use--;
 369        }
 370        led->blink = 0;
 371        led->bank = -1;
 372}
 373
 374static int led_prepare(struct tca6507_led *led)
 375{
 376        /* Assign this led to a bank, configuring that bank if necessary. */
 377        int level = TO_LEVEL(led->led_cdev.brightness);
 378        struct tca6507_chip *tca = led->chip;
 379        int c1, c2;
 380        int i;
 381        struct bank *b;
 382        int need_init = 0;
 383
 384        led->led_cdev.brightness = TO_BRIGHT(level);
 385        if (level == 0) {
 386                set_select(tca, led->num, TCA6507_LS_LED_OFF);
 387                return 0;
 388        }
 389
 390        if (led->ontime == 0 || led->offtime == 0) {
 391                /*
 392                 * Just set the brightness, choosing first usable bank.
 393                 * If none perfect, choose best.
 394                 * Count backwards so we check MASTER bank first
 395                 * to avoid wasting a timer.
 396                 */
 397                int best = -1;/* full-on */
 398                int diff = 15-level;
 399
 400                if (level == 15) {
 401                        set_select(tca, led->num, TCA6507_LS_LED_ON);
 402                        return 0;
 403                }
 404
 405                for (i = MASTER; i >= BANK0; i--) {
 406                        int d;
 407                        if (tca->bank[i].level == level ||
 408                            tca->bank[i].level_use == 0) {
 409                                best = i;
 410                                break;
 411                        }
 412                        d = abs(level - tca->bank[i].level);
 413                        if (d < diff) {
 414                                diff = d;
 415                                best = i;
 416                        }
 417                }
 418                if (best == -1) {
 419                        /* Best brightness is full-on */
 420                        set_select(tca, led->num, TCA6507_LS_LED_ON);
 421                        led->led_cdev.brightness = LED_FULL;
 422                        return 0;
 423                }
 424
 425                if (!tca->bank[best].level_use)
 426                        set_level(tca, best, level);
 427
 428                tca->bank[best].level_use++;
 429                led->bank = best;
 430                set_select(tca, led->num, bank_source[best]);
 431                led->led_cdev.brightness = TO_BRIGHT(tca->bank[best].level);
 432                return 0;
 433        }
 434
 435        /*
 436         * We have on/off time so we need to try to allocate a timing bank.
 437         * First check if times are compatible with hardware and give up if
 438         * not.
 439         */
 440        if (choose_times(led->ontime, &c1, &c2) < 0)
 441                return -EINVAL;
 442        if (choose_times(led->offtime, &c1, &c2) < 0)
 443                return -EINVAL;
 444
 445        for (i = BANK0; i <= BANK1; i++) {
 446                if (tca->bank[i].level_use == 0)
 447                        /* not in use - it is ours! */
 448                        break;
 449                if (tca->bank[i].level != level)
 450                        /* Incompatible level - skip */
 451                        /* FIX: if timer matches we maybe should consider
 452                         * this anyway...
 453                         */
 454                        continue;
 455
 456                if (tca->bank[i].time_use == 0)
 457                        /* Timer not in use, and level matches - use it */
 458                        break;
 459
 460                if (!(tca->bank[i].on_dflt ||
 461                      led->on_dflt ||
 462                      tca->bank[i].ontime == led->ontime))
 463                        /* on time is incompatible */
 464                        continue;
 465
 466                if (!(tca->bank[i].off_dflt ||
 467                      led->off_dflt ||
 468                      tca->bank[i].offtime == led->offtime))
 469                        /* off time is incompatible */
 470                        continue;
 471
 472                /* looks like a suitable match */
 473                break;
 474        }
 475
 476        if (i > BANK1)
 477                /* Nothing matches - how sad */
 478                return -EINVAL;
 479
 480        b = &tca->bank[i];
 481        if (b->level_use == 0)
 482                set_level(tca, i, level);
 483        b->level_use++;
 484        led->bank = i;
 485
 486        if (b->on_dflt ||
 487            !led->on_dflt ||
 488            b->time_use == 0) {
 489                b->ontime = led->ontime;
 490                b->on_dflt = led->on_dflt;
 491                need_init = 1;
 492        }
 493
 494        if (b->off_dflt ||
 495            !led->off_dflt ||
 496            b->time_use == 0) {
 497                b->offtime = led->offtime;
 498                b->off_dflt = led->off_dflt;
 499                need_init = 1;
 500        }
 501
 502        if (need_init)
 503                set_times(tca, i);
 504
 505        led->ontime = b->ontime;
 506        led->offtime = b->offtime;
 507
 508        b->time_use++;
 509        led->blink = 1;
 510        led->led_cdev.brightness = TO_BRIGHT(b->level);
 511        set_select(tca, led->num, blink_source[i]);
 512        return 0;
 513}
 514
 515static int led_assign(struct tca6507_led *led)
 516{
 517        struct tca6507_chip *tca = led->chip;
 518        int err;
 519        unsigned long flags;
 520
 521        spin_lock_irqsave(&tca->lock, flags);
 522        led_release(led);
 523        err = led_prepare(led);
 524        if (err) {
 525                /*
 526                 * Can only fail on timer setup.  In that case we need to
 527                 * re-establish as steady level.
 528                 */
 529                led->ontime = 0;
 530                led->offtime = 0;
 531                led_prepare(led);
 532        }
 533        spin_unlock_irqrestore(&tca->lock, flags);
 534
 535        if (tca->reg_set)
 536                schedule_work(&tca->work);
 537        return err;
 538}
 539
 540static void tca6507_brightness_set(struct led_classdev *led_cdev,
 541                                   enum led_brightness brightness)
 542{
 543        struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
 544                                               led_cdev);
 545        led->led_cdev.brightness = brightness;
 546        led->ontime = 0;
 547        led->offtime = 0;
 548        led_assign(led);
 549}
 550
 551static int tca6507_blink_set(struct led_classdev *led_cdev,
 552                             unsigned long *delay_on,
 553                             unsigned long *delay_off)
 554{
 555        struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
 556                                               led_cdev);
 557
 558        if (*delay_on == 0)
 559                led->on_dflt = 1;
 560        else if (delay_on != &led_cdev->blink_delay_on)
 561                led->on_dflt = 0;
 562        led->ontime = *delay_on;
 563
 564        if (*delay_off == 0)
 565                led->off_dflt = 1;
 566        else if (delay_off != &led_cdev->blink_delay_off)
 567                led->off_dflt = 0;
 568        led->offtime = *delay_off;
 569
 570        if (led->ontime == 0)
 571                led->ontime = 512;
 572        if (led->offtime == 0)
 573                led->offtime = 512;
 574
 575        if (led->led_cdev.brightness == LED_OFF)
 576                led->led_cdev.brightness = LED_FULL;
 577        if (led_assign(led) < 0) {
 578                led->ontime = 0;
 579                led->offtime = 0;
 580                led->led_cdev.brightness = LED_OFF;
 581                return -EINVAL;
 582        }
 583        *delay_on = led->ontime;
 584        *delay_off = led->offtime;
 585        return 0;
 586}
 587
 588#ifdef CONFIG_GPIOLIB
 589static void tca6507_gpio_set_value(struct gpio_chip *gc,
 590                                   unsigned offset, int val)
 591{
 592        struct tca6507_chip *tca = container_of(gc, struct tca6507_chip, gpio);
 593        unsigned long flags;
 594
 595        spin_lock_irqsave(&tca->lock, flags);
 596        /*
 597         * 'OFF' is floating high, and 'ON' is pulled down, so it has the
 598         * inverse sense of 'val'.
 599         */
 600        set_select(tca, tca->gpio_map[offset],
 601                   val ? TCA6507_LS_LED_OFF : TCA6507_LS_LED_ON);
 602        spin_unlock_irqrestore(&tca->lock, flags);
 603        if (tca->reg_set)
 604                schedule_work(&tca->work);
 605}
 606
 607static int tca6507_gpio_direction_output(struct gpio_chip *gc,
 608                                          unsigned offset, int val)
 609{
 610        tca6507_gpio_set_value(gc, offset, val);
 611        return 0;
 612}
 613
 614static int tca6507_probe_gpios(struct i2c_client *client,
 615                               struct tca6507_chip *tca,
 616                               struct tca6507_platform_data *pdata)
 617{
 618        int err;
 619        int i = 0;
 620        int gpios = 0;
 621
 622        for (i = 0; i < NUM_LEDS; i++)
 623                if (pdata->leds.leds[i].name && pdata->leds.leds[i].flags) {
 624                        /* Configure as a gpio */
 625                        tca->gpio_name[gpios] = pdata->leds.leds[i].name;
 626                        tca->gpio_map[gpios] = i;
 627                        gpios++;
 628                }
 629
 630        if (!gpios)
 631                return 0;
 632
 633        tca->gpio.label = "gpio-tca6507";
 634        tca->gpio.names = tca->gpio_name;
 635        tca->gpio.ngpio = gpios;
 636        tca->gpio.base = pdata->gpio_base;
 637        tca->gpio.owner = THIS_MODULE;
 638        tca->gpio.direction_output = tca6507_gpio_direction_output;
 639        tca->gpio.set = tca6507_gpio_set_value;
 640        tca->gpio.dev = &client->dev;
 641        err = gpiochip_add(&tca->gpio);
 642        if (err) {
 643                tca->gpio.ngpio = 0;
 644                return err;
 645        }
 646        if (pdata->setup)
 647                pdata->setup(tca->gpio.base, tca->gpio.ngpio);
 648        return 0;
 649}
 650
 651static void tca6507_remove_gpio(struct tca6507_chip *tca)
 652{
 653        if (tca->gpio.ngpio) {
 654                int err = gpiochip_remove(&tca->gpio);
 655                dev_err(&tca->client->dev, "%s failed, %d\n",
 656                        "gpiochip_remove()", err);
 657        }
 658}
 659#else /* CONFIG_GPIOLIB */
 660static int tca6507_probe_gpios(struct i2c_client *client,
 661                               struct tca6507_chip *tca,
 662                               struct tca6507_platform_data *pdata)
 663{
 664        return 0;
 665}
 666static void tca6507_remove_gpio(struct tca6507_chip *tca)
 667{
 668}
 669#endif /* CONFIG_GPIOLIB */
 670
 671#ifdef CONFIG_OF
 672static struct tca6507_platform_data *
 673tca6507_led_dt_init(struct i2c_client *client)
 674{
 675        struct device_node *np = client->dev.of_node, *child;
 676        struct tca6507_platform_data *pdata;
 677        struct led_info *tca_leds;
 678        int count;
 679
 680        count = of_get_child_count(np);
 681        if (!count || count > NUM_LEDS)
 682                return ERR_PTR(-ENODEV);
 683
 684        tca_leds = devm_kzalloc(&client->dev,
 685                        sizeof(struct led_info) * count, GFP_KERNEL);
 686        if (!tca_leds)
 687                return ERR_PTR(-ENOMEM);
 688
 689        for_each_child_of_node(np, child) {
 690                struct led_info led;
 691                u32 reg;
 692                int ret;
 693
 694                led.name =
 695                        of_get_property(child, "label", NULL) ? : child->name;
 696                led.default_trigger =
 697                        of_get_property(child, "linux,default-trigger", NULL);
 698
 699                ret = of_property_read_u32(child, "reg", &reg);
 700                if (ret != 0)
 701                        continue;
 702
 703                tca_leds[reg] = led;
 704        }
 705        pdata = devm_kzalloc(&client->dev,
 706                        sizeof(struct tca6507_platform_data), GFP_KERNEL);
 707        if (!pdata)
 708                return ERR_PTR(-ENOMEM);
 709
 710        pdata->leds.leds = tca_leds;
 711        pdata->leds.num_leds = count;
 712
 713        return pdata;
 714}
 715
 716static const struct of_device_id of_tca6507_leds_match[] = {
 717        { .compatible = "ti,tca6507", },
 718        {},
 719};
 720
 721#else
 722static struct tca6507_platform_data *
 723tca6507_led_dt_init(struct i2c_client *client)
 724{
 725        return ERR_PTR(-ENODEV);
 726}
 727
 728#endif
 729
 730static int tca6507_probe(struct i2c_client *client,
 731                const struct i2c_device_id *id)
 732{
 733        struct tca6507_chip *tca;
 734        struct i2c_adapter *adapter;
 735        struct tca6507_platform_data *pdata;
 736        int err;
 737        int i = 0;
 738
 739        adapter = to_i2c_adapter(client->dev.parent);
 740        pdata = client->dev.platform_data;
 741
 742        if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
 743                return -EIO;
 744
 745        if (!pdata || pdata->leds.num_leds != NUM_LEDS) {
 746                pdata = tca6507_led_dt_init(client);
 747                if (IS_ERR(pdata)) {
 748                        dev_err(&client->dev, "Need %d entries in platform-data list\n",
 749                                NUM_LEDS);
 750                        return PTR_ERR(pdata);
 751                }
 752        }
 753        tca = devm_kzalloc(&client->dev, sizeof(*tca), GFP_KERNEL);
 754        if (!tca)
 755                return -ENOMEM;
 756
 757        tca->client = client;
 758        INIT_WORK(&tca->work, tca6507_work);
 759        spin_lock_init(&tca->lock);
 760        i2c_set_clientdata(client, tca);
 761
 762        for (i = 0; i < NUM_LEDS; i++) {
 763                struct tca6507_led *l = tca->leds + i;
 764
 765                l->chip = tca;
 766                l->num = i;
 767                if (pdata->leds.leds[i].name && !pdata->leds.leds[i].flags) {
 768                        l->led_cdev.name = pdata->leds.leds[i].name;
 769                        l->led_cdev.default_trigger
 770                                = pdata->leds.leds[i].default_trigger;
 771                        l->led_cdev.brightness_set = tca6507_brightness_set;
 772                        l->led_cdev.blink_set = tca6507_blink_set;
 773                        l->bank = -1;
 774                        err = led_classdev_register(&client->dev,
 775                                                    &l->led_cdev);
 776                        if (err < 0)
 777                                goto exit;
 778                }
 779        }
 780        err = tca6507_probe_gpios(client, tca, pdata);
 781        if (err)
 782                goto exit;
 783        /* set all registers to known state - zero */
 784        tca->reg_set = 0x7f;
 785        schedule_work(&tca->work);
 786
 787        return 0;
 788exit:
 789        while (i--) {
 790                if (tca->leds[i].led_cdev.name)
 791                        led_classdev_unregister(&tca->leds[i].led_cdev);
 792        }
 793        return err;
 794}
 795
 796static int tca6507_remove(struct i2c_client *client)
 797{
 798        int i;
 799        struct tca6507_chip *tca = i2c_get_clientdata(client);
 800        struct tca6507_led *tca_leds = tca->leds;
 801
 802        for (i = 0; i < NUM_LEDS; i++) {
 803                if (tca_leds[i].led_cdev.name)
 804                        led_classdev_unregister(&tca_leds[i].led_cdev);
 805        }
 806        tca6507_remove_gpio(tca);
 807        cancel_work_sync(&tca->work);
 808
 809        return 0;
 810}
 811
 812static struct i2c_driver tca6507_driver = {
 813        .driver   = {
 814                .name    = "leds-tca6507",
 815                .owner   = THIS_MODULE,
 816                .of_match_table = of_match_ptr(of_tca6507_leds_match),
 817        },
 818        .probe    = tca6507_probe,
 819        .remove   = tca6507_remove,
 820        .id_table = tca6507_id,
 821};
 822
 823module_i2c_driver(tca6507_driver);
 824
 825MODULE_AUTHOR("NeilBrown <neilb@suse.de>");
 826MODULE_DESCRIPTION("TCA6507 LED/GPO driver");
 827MODULE_LICENSE("GPL v2");
 828
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