drivers/leds/leds-netxbig.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
   4  *
   5  * Copyright (C) 2010 LaCie
   6  *
   7  * Author: Simon Guinot <sguinot@lacie.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/irq.h>
  12 #include <linux/slab.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/gpio/consumer.h>
  16 #include <linux/leds.h>
  17 #include <linux/of.h>
  18 #include <linux/of_platform.h>
  19
  20 struct netxbig_gpio_ext {
  21         struct gpio_desc **addr;
  22         int             num_addr;
  23         struct gpio_desc **data;
  24         int             num_data;
  25         struct gpio_desc *enable;
  26 };
  27
  28 enum netxbig_led_mode {
  29         NETXBIG_LED_OFF,
  30         NETXBIG_LED_ON,
  31         NETXBIG_LED_SATA,
  32         NETXBIG_LED_TIMER1,
  33         NETXBIG_LED_TIMER2,
  34         NETXBIG_LED_MODE_NUM,
  35 };
  36
  37 #define NETXBIG_LED_INVALID_MODE NETXBIG_LED_MODE_NUM
  38
  39 struct netxbig_led_timer {
  40         unsigned long           delay_on;
  41         unsigned long           delay_off;
  42         enum netxbig_led_mode   mode;
  43 };
  44
  45 struct netxbig_led {
  46         const char      *name;
  47         const char      *default_trigger;
  48         int             mode_addr;
  49         int             *mode_val;
  50         int             bright_addr;
  51         int             bright_max;
  52 };
  53
  54 struct netxbig_led_platform_data {
  55         struct netxbig_gpio_ext *gpio_ext;
  56         struct netxbig_led_timer *timer;
  57         int                     num_timer;
  58         struct netxbig_led      *leds;
  59         int                     num_leds;
  60 };
  61
  62 /*
  63  * GPIO extension bus.
  64  */
  65
  66 static DEFINE_SPINLOCK(gpio_ext_lock);
  67
  68 static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  69 {
  70         int pin;
  71
  72         for (pin = 0; pin < gpio_ext->num_addr; pin++)
  73                 gpiod_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  74 }
  75
  76 static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  77 {
  78         int pin;
  79
  80         for (pin = 0; pin < gpio_ext->num_data; pin++)
  81                 gpiod_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  82 }
  83
  84 static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  85 {
  86         /* Enable select is done on the raising edge. */
  87         gpiod_set_value(gpio_ext->enable, 0);
  88         gpiod_set_value(gpio_ext->enable, 1);
  89 }
  90
  91 static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  92                                int addr, int value)
  93 {
  94         unsigned long flags;
  95
  96         spin_lock_irqsave(&gpio_ext_lock, flags);
  97         gpio_ext_set_addr(gpio_ext, addr);
  98         gpio_ext_set_data(gpio_ext, value);
  99         gpio_ext_enable_select(gpio_ext);
 100         spin_unlock_irqrestore(&gpio_ext_lock, flags);
 101 }
 102
 103 /*
 104  * Class LED driver.
 105  */
 106
 107 struct netxbig_led_data {
 108         struct netxbig_gpio_ext *gpio_ext;
 109         struct led_classdev     cdev;
 110         int                     mode_addr;
 111         int                     *mode_val;
 112         int                     bright_addr;
 113         struct                  netxbig_led_timer *timer;
 114         int                     num_timer;
 115         enum netxbig_led_mode   mode;
 116         int                     sata;
 117         spinlock_t              lock;
 118 };
 119
 120 static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 121                                       unsigned long delay_on,
 122                                       unsigned long delay_off,
 123                                       struct netxbig_led_timer *timer,
 124                                       int num_timer)
 125 {
 126         int i;
 127
 128         for (i = 0; i < num_timer; i++) {
 129                 if (timer[i].delay_on == delay_on &&
 130                     timer[i].delay_off == delay_off) {
 131                         *mode = timer[i].mode;
 132                         return 0;
 133                 }
 134         }
 135         return -EINVAL;
 136 }
 137
 138 static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 139                                  unsigned long *delay_on,
 140                                  unsigned long *delay_off)
 141 {
 142         struct netxbig_led_data *led_dat =
 143                 container_of(led_cdev, struct netxbig_led_data, cdev);
 144         enum netxbig_led_mode mode;
 145         int mode_val;
 146         int ret;
 147
 148         /* Look for a LED mode with the requested timer frequency. */
 149         ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 150                                          led_dat->timer, led_dat->num_timer);
 151         if (ret < 0)
 152                 return ret;
 153
 154         mode_val = led_dat->mode_val[mode];
 155         if (mode_val == NETXBIG_LED_INVALID_MODE)
 156                 return -EINVAL;
 157
 158         spin_lock_irq(&led_dat->lock);
 159
 160         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 161         led_dat->mode = mode;
 162
 163         spin_unlock_irq(&led_dat->lock);
 164
 165         return 0;
 166 }
 167
 168 static void netxbig_led_set(struct led_classdev *led_cdev,
 169                             enum led_brightness value)
 170 {
 171         struct netxbig_led_data *led_dat =
 172                 container_of(led_cdev, struct netxbig_led_data, cdev);
 173         enum netxbig_led_mode mode;
 174         int mode_val;
 175         int set_brightness = 1;
 176         unsigned long flags;
 177
 178         spin_lock_irqsave(&led_dat->lock, flags);
 179
 180         if (value == LED_OFF) {
 181                 mode = NETXBIG_LED_OFF;
 182                 set_brightness = 0;
 183         } else {
 184                 if (led_dat->sata)
 185                         mode = NETXBIG_LED_SATA;
 186                 else if (led_dat->mode == NETXBIG_LED_OFF)
 187                         mode = NETXBIG_LED_ON;
 188                 else /* Keep 'timer' mode. */
 189                         mode = led_dat->mode;
 190         }
 191         mode_val = led_dat->mode_val[mode];
 192
 193         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 194         led_dat->mode = mode;
 195         /*
 196          * Note that the brightness register is shared between all the
 197          * SATA LEDs. So, change the brightness setting for a single
 198          * SATA LED will affect all the others.
 199          */
 200         if (set_brightness)
 201                 gpio_ext_set_value(led_dat->gpio_ext,
 202                                    led_dat->bright_addr, value);
 203
 204         spin_unlock_irqrestore(&led_dat->lock, flags);
 205 }
 206
 207 static ssize_t sata_store(struct device *dev,
 208                           struct device_attribute *attr,
 209                           const char *buff, size_t count)
 210 {
 211         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 212         struct netxbig_led_data *led_dat =
 213                 container_of(led_cdev, struct netxbig_led_data, cdev);
 214         unsigned long enable;
 215         enum netxbig_led_mode mode;
 216         int mode_val;
 217         int ret;
 218
 219         ret = kstrtoul(buff, 10, &enable);
 220         if (ret < 0)
 221                 return ret;
 222
 223         enable = !!enable;
 224
 225         spin_lock_irq(&led_dat->lock);
 226
 227         if (led_dat->sata == enable) {
 228                 ret = count;
 229                 goto exit_unlock;
 230         }
 231
 232         if (led_dat->mode != NETXBIG_LED_ON &&
 233             led_dat->mode != NETXBIG_LED_SATA)
 234                 mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 235         else if (enable)
 236                 mode = NETXBIG_LED_SATA;
 237         else
 238                 mode = NETXBIG_LED_ON;
 239
 240         mode_val = led_dat->mode_val[mode];
 241         if (mode_val == NETXBIG_LED_INVALID_MODE) {
 242                 ret = -EINVAL;
 243                 goto exit_unlock;
 244         }
 245
 246         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 247         led_dat->mode = mode;
 248         led_dat->sata = enable;
 249
 250         ret = count;
 251
 252 exit_unlock:
 253         spin_unlock_irq(&led_dat->lock);
 254
 255         return ret;
 256 }
 257
 258 static ssize_t sata_show(struct device *dev,
 259                          struct device_attribute *attr, char *buf)
 260 {
 261         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 262         struct netxbig_led_data *led_dat =
 263                 container_of(led_cdev, struct netxbig_led_data, cdev);
 264
 265         return sprintf(buf, "%d\n", led_dat->sata);
 266 }
 267
 268 static DEVICE_ATTR_RW(sata);
 269
 270 static struct attribute *netxbig_led_attrs[] = {
 271         &dev_attr_sata.attr,
 272         NULL
 273 };
 274 ATTRIBUTE_GROUPS(netxbig_led);
 275
 276 static int create_netxbig_led(struct platform_device *pdev,
 277                               struct netxbig_led_platform_data *pdata,
 278                               struct netxbig_led_data *led_dat,
 279                               const struct netxbig_led *template)
 280 {
 281         spin_lock_init(&led_dat->lock);
 282         led_dat->gpio_ext = pdata->gpio_ext;
 283         led_dat->cdev.name = template->name;
 284         led_dat->cdev.default_trigger = template->default_trigger;
 285         led_dat->cdev.blink_set = netxbig_led_blink_set;
 286         led_dat->cdev.brightness_set = netxbig_led_set;
 287         /*
 288          * Because the GPIO extension bus don't allow to read registers
 289          * value, there is no way to probe the LED initial state.
 290          * So, the initial sysfs LED value for the "brightness" and "sata"
 291          * attributes are inconsistent.
 292          *
 293          * Note that the initial LED state can't be reconfigured.
 294          * The reason is that the LED behaviour must stay uniform during
 295          * the whole boot process (bootloader+linux).
 296          */
 297         led_dat->sata = 0;
 298         led_dat->cdev.brightness = LED_OFF;
 299         led_dat->cdev.max_brightness = template->bright_max;
 300         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 301         led_dat->mode_addr = template->mode_addr;
 302         led_dat->mode_val = template->mode_val;
 303         led_dat->bright_addr = template->bright_addr;
 304         led_dat->timer = pdata->timer;
 305         led_dat->num_timer = pdata->num_timer;
 306         /*
 307          * If available, expose the SATA activity blink capability through
 308          * a "sata" sysfs attribute.
 309          */
 310         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 311                 led_dat->cdev.groups = netxbig_led_groups;
 312
 313         return devm_led_classdev_register(&pdev->dev, &led_dat->cdev);
 314 }
 315
 316 /**
 317  * netxbig_gpio_ext_remove() - Clean up GPIO extension data
 318  * @data: managed resource data to clean up
 319  *
 320  * Since we pick GPIO descriptors from another device than the device our
 321  * driver is probing to, we need to register a specific callback to free
 322  * these up using managed resources.
 323  */
 324 static void netxbig_gpio_ext_remove(void *data)
 325 {
 326         struct netxbig_gpio_ext *gpio_ext = data;
 327         int i;
 328
 329         for (i = 0; i < gpio_ext->num_addr; i++)
 330                 gpiod_put(gpio_ext->addr[i]);
 331         for (i = 0; i < gpio_ext->num_data; i++)
 332                 gpiod_put(gpio_ext->data[i]);
 333         gpiod_put(gpio_ext->enable);
 334 }
 335
 336 /**
 337  * netxbig_gpio_ext_get() - Obtain GPIO extension device data
 338  * @dev: main LED device
 339  * @gpio_ext_dev: the GPIO extension device
 340  * @gpio_ext: the data structure holding the GPIO extension data
 341  *
 342  * This function walks the subdevice that only contain GPIO line
 343  * handles in the device tree and obtains the GPIO descriptors from that
 344  * device.
 345  */
 346 static int netxbig_gpio_ext_get(struct device *dev,
 347                                 struct device *gpio_ext_dev,
 348                                 struct netxbig_gpio_ext *gpio_ext)
 349 {
 350         struct gpio_desc **addr, **data;
 351         int num_addr, num_data;
 352         struct gpio_desc *gpiod;
 353         int ret;
 354         int i;
 355
 356         ret = gpiod_count(gpio_ext_dev, "addr");
 357         if (ret < 0) {
 358                 dev_err(dev,
 359                         "Failed to count GPIOs in DT property addr-gpios\n");
 360                 return ret;
 361         }
 362         num_addr = ret;
 363         addr = devm_kcalloc(dev, num_addr, sizeof(*addr), GFP_KERNEL);
 364         if (!addr)
 365                 return -ENOMEM;
 366
 367         /*
 368          * We cannot use devm_ managed resources with these GPIO descriptors
 369          * since they are associated with the "GPIO extension device" which
 370          * does not probe any driver. The device tree parser will however
 371          * populate a platform device for it so we can anyway obtain the
 372          * GPIO descriptors from the device.
 373          */
 374         for (i = 0; i < num_addr; i++) {
 375                 gpiod = gpiod_get_index(gpio_ext_dev, "addr", i,
 376                                         GPIOD_OUT_LOW);
 377                 if (IS_ERR(gpiod))
 378                         return PTR_ERR(gpiod);
 379                 gpiod_set_consumer_name(gpiod, "GPIO extension addr");
 380                 addr[i] = gpiod;
 381         }
 382         gpio_ext->addr = addr;
 383         gpio_ext->num_addr = num_addr;
 384
 385         ret = gpiod_count(gpio_ext_dev, "data");
 386         if (ret < 0) {
 387                 dev_err(dev,
 388                         "Failed to count GPIOs in DT property data-gpios\n");
 389                 return ret;
 390         }
 391         num_data = ret;
 392         data = devm_kcalloc(dev, num_data, sizeof(*data), GFP_KERNEL);
 393         if (!data)
 394                 return -ENOMEM;
 395
 396         for (i = 0; i < num_data; i++) {
 397                 gpiod = gpiod_get_index(gpio_ext_dev, "data", i,
 398                                         GPIOD_OUT_LOW);
 399                 if (IS_ERR(gpiod))
 400                         return PTR_ERR(gpiod);
 401                 gpiod_set_consumer_name(gpiod, "GPIO extension data");
 402                 data[i] = gpiod;
 403         }
 404         gpio_ext->data = data;
 405         gpio_ext->num_data = num_data;
 406
 407         gpiod = gpiod_get(gpio_ext_dev, "enable", GPIOD_OUT_LOW);
 408         if (IS_ERR(gpiod)) {
 409                 dev_err(dev,
 410                         "Failed to get GPIO from DT property enable-gpio\n");
 411                 return PTR_ERR(gpiod);
 412         }
 413         gpiod_set_consumer_name(gpiod, "GPIO extension enable");
 414         gpio_ext->enable = gpiod;
 415
 416         return devm_add_action_or_reset(dev, netxbig_gpio_ext_remove, gpio_ext);
 417 }
 418
 419 static int netxbig_leds_get_of_pdata(struct device *dev,
 420                                      struct netxbig_led_platform_data *pdata)
 421 {
 422         struct device_node *np = dev_of_node(dev);
 423         struct device_node *gpio_ext_np;
 424         struct platform_device *gpio_ext_pdev;
 425         struct device *gpio_ext_dev;
 426         struct netxbig_gpio_ext *gpio_ext;
 427         struct netxbig_led_timer *timers;
 428         struct netxbig_led *leds, *led;
 429         int num_timers;
 430         int num_leds = 0;
 431         int ret;
 432         int i;
 433
 434         /* GPIO extension */
 435         gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
 436         if (!gpio_ext_np) {
 437                 dev_err(dev, "Failed to get DT handle gpio-ext\n");
 438                 return -EINVAL;
 439         }
 440         gpio_ext_pdev = of_find_device_by_node(gpio_ext_np);
 441         if (!gpio_ext_pdev) {
 442                 dev_err(dev, "Failed to find platform device for gpio-ext\n");
 443                 return -ENODEV;
 444         }
 445         gpio_ext_dev = &gpio_ext_pdev->dev;
 446
 447         gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
 448         if (!gpio_ext) {
 449                 of_node_put(gpio_ext_np);
 450                 ret = -ENOMEM;
 451                 goto put_device;
 452         }
 453         ret = netxbig_gpio_ext_get(dev, gpio_ext_dev, gpio_ext);
 454         of_node_put(gpio_ext_np);
 455         if (ret)
 456                 goto put_device;
 457         pdata->gpio_ext = gpio_ext;
 458
 459         /* Timers (optional) */
 460         ret = of_property_count_u32_elems(np, "timers");
 461         if (ret > 0) {
 462                 if (ret % 3) {
 463                         ret = -EINVAL;
 464                         goto put_device;
 465                 }
 466
 467                 num_timers = ret / 3;
 468                 timers = devm_kcalloc(dev, num_timers, sizeof(*timers),
 469                                       GFP_KERNEL);
 470                 if (!timers) {
 471                         ret = -ENOMEM;
 472                         goto put_device;
 473                 }
 474                 for (i = 0; i < num_timers; i++) {
 475                         u32 tmp;
 476
 477                         of_property_read_u32_index(np, "timers", 3 * i,
 478                                                    &timers[i].mode);
 479                         if (timers[i].mode >= NETXBIG_LED_MODE_NUM) {
 480                                 ret = -EINVAL;
 481                                 goto put_device;
 482                         }
 483                         of_property_read_u32_index(np, "timers",
 484                                                    3 * i + 1, &tmp);
 485                         timers[i].delay_on = tmp;
 486                         of_property_read_u32_index(np, "timers",
 487                                                    3 * i + 2, &tmp);
 488                         timers[i].delay_off = tmp;
 489                 }
 490                 pdata->timer = timers;
 491                 pdata->num_timer = num_timers;
 492         }
 493
 494         /* LEDs */
 495         num_leds = of_get_available_child_count(np);
 496         if (!num_leds) {
 497                 dev_err(dev, "No LED subnodes found in DT\n");
 498                 ret = -ENODEV;
 499                 goto put_device;
 500         }
 501
 502         leds = devm_kcalloc(dev, num_leds, sizeof(*leds), GFP_KERNEL);
 503         if (!leds) {
 504                 ret = -ENOMEM;
 505                 goto put_device;
 506         }
 507
 508         led = leds;
 509         for_each_available_child_of_node_scoped(np, child) {
 510                 const char *string;
 511                 int *mode_val;
 512                 int num_modes;
 513
 514                 ret = of_property_read_u32(child, "mode-addr",
 515                                            &led->mode_addr);
 516                 if (ret)
 517                         goto put_device;
 518
 519                 ret = of_property_read_u32(child, "bright-addr",
 520                                            &led->bright_addr);
 521                 if (ret)
 522                         goto put_device;
 523
 524                 ret = of_property_read_u32(child, "max-brightness",
 525                                            &led->bright_max);
 526                 if (ret)
 527                         goto put_device;
 528
 529                 mode_val =
 530                         devm_kcalloc(dev,
 531                                      NETXBIG_LED_MODE_NUM, sizeof(*mode_val),
 532                                      GFP_KERNEL);
 533                 if (!mode_val) {
 534                         ret = -ENOMEM;
 535                         goto put_device;
 536                 }
 537
 538                 for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
 539                         mode_val[i] = NETXBIG_LED_INVALID_MODE;
 540
 541                 ret = of_property_count_u32_elems(child, "mode-val");
 542                 if (ret < 0 || ret % 2) {
 543                         ret = -EINVAL;
 544                         goto put_device;
 545                 }
 546                 num_modes = ret / 2;
 547                 if (num_modes > NETXBIG_LED_MODE_NUM) {
 548                         ret = -EINVAL;
 549                         goto put_device;
 550                 }
 551
 552                 for (i = 0; i < num_modes; i++) {
 553                         int mode;
 554                         int val;
 555
 556                         of_property_read_u32_index(child,
 557                                                    "mode-val", 2 * i, &mode);
 558                         of_property_read_u32_index(child,
 559                                                    "mode-val", 2 * i + 1, &val);
 560                         if (mode >= NETXBIG_LED_MODE_NUM) {
 561                                 ret = -EINVAL;
 562                                 goto put_device;
 563                         }
 564                         mode_val[mode] = val;
 565                 }
 566                 led->mode_val = mode_val;
 567
 568                 if (!of_property_read_string(child, "label", &string))
 569                         led->name = string;
 570                 else
 571                         led->name = child->name;
 572
 573                 if (!of_property_read_string(child,
 574                                              "linux,default-trigger", &string))
 575                         led->default_trigger = string;
 576
 577                 led++;
 578         }
 579
 580         pdata->leds = leds;
 581         pdata->num_leds = num_leds;
 582
 583         return 0;
 584
 585 put_device:
 586         put_device(gpio_ext_dev);
 587         return ret;
 588 }
 589
 590 static const struct of_device_id of_netxbig_leds_match[] = {
 591         { .compatible = "lacie,netxbig-leds", },
 592         {},
 593 };
 594 MODULE_DEVICE_TABLE(of, of_netxbig_leds_match);
 595
 596 static int netxbig_led_probe(struct platform_device *pdev)
 597 {
 598         struct netxbig_led_platform_data *pdata;
 599         struct netxbig_led_data *leds_data;
 600         int i;
 601         int ret;
 602
 603         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 604         if (!pdata)
 605                 return -ENOMEM;
 606         ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
 607         if (ret)
 608                 return ret;
 609
 610         leds_data = devm_kcalloc(&pdev->dev,
 611                                  pdata->num_leds, sizeof(*leds_data),
 612                                  GFP_KERNEL);
 613         if (!leds_data)
 614                 return -ENOMEM;
 615
 616         for (i = 0; i < pdata->num_leds; i++) {
 617                 ret = create_netxbig_led(pdev, pdata,
 618                                          &leds_data[i], &pdata->leds[i]);
 619                 if (ret < 0)
 620                         return ret;
 621         }
 622
 623         return 0;
 624 }
 625
 626 static struct platform_driver netxbig_led_driver = {
 627         .probe          = netxbig_led_probe,
 628         .driver         = {
 629                 .name           = "leds-netxbig",
 630                 .of_match_table = of_netxbig_leds_match,
 631         },
 632 };
 633
 634 module_platform_driver(netxbig_led_driver);
 635
 636 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 637 MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 638 MODULE_LICENSE("GPL");
 639 MODULE_ALIAS("platform:leds-netxbig");