linux/drivers/leds/leds-netxbig.c
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   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.h>
  16#include <linux/of_gpio.h>
  17#include <linux/leds.h>
  18
  19struct netxbig_gpio_ext {
  20        unsigned int    *addr;
  21        int             num_addr;
  22        unsigned int    *data;
  23        int             num_data;
  24        unsigned int    enable;
  25};
  26
  27enum netxbig_led_mode {
  28        NETXBIG_LED_OFF,
  29        NETXBIG_LED_ON,
  30        NETXBIG_LED_SATA,
  31        NETXBIG_LED_TIMER1,
  32        NETXBIG_LED_TIMER2,
  33        NETXBIG_LED_MODE_NUM,
  34};
  35
  36#define NETXBIG_LED_INVALID_MODE NETXBIG_LED_MODE_NUM
  37
  38struct netxbig_led_timer {
  39        unsigned long           delay_on;
  40        unsigned long           delay_off;
  41        enum netxbig_led_mode   mode;
  42};
  43
  44struct netxbig_led {
  45        const char      *name;
  46        const char      *default_trigger;
  47        int             mode_addr;
  48        int             *mode_val;
  49        int             bright_addr;
  50        int             bright_max;
  51};
  52
  53struct netxbig_led_platform_data {
  54        struct netxbig_gpio_ext *gpio_ext;
  55        struct netxbig_led_timer *timer;
  56        int                     num_timer;
  57        struct netxbig_led      *leds;
  58        int                     num_leds;
  59};
  60
  61/*
  62 * GPIO extension bus.
  63 */
  64
  65static DEFINE_SPINLOCK(gpio_ext_lock);
  66
  67static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  68{
  69        int pin;
  70
  71        for (pin = 0; pin < gpio_ext->num_addr; pin++)
  72                gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  73}
  74
  75static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  76{
  77        int pin;
  78
  79        for (pin = 0; pin < gpio_ext->num_data; pin++)
  80                gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  81}
  82
  83static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  84{
  85        /* Enable select is done on the raising edge. */
  86        gpio_set_value(gpio_ext->enable, 0);
  87        gpio_set_value(gpio_ext->enable, 1);
  88}
  89
  90static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  91                               int addr, int value)
  92{
  93        unsigned long flags;
  94
  95        spin_lock_irqsave(&gpio_ext_lock, flags);
  96        gpio_ext_set_addr(gpio_ext, addr);
  97        gpio_ext_set_data(gpio_ext, value);
  98        gpio_ext_enable_select(gpio_ext);
  99        spin_unlock_irqrestore(&gpio_ext_lock, flags);
 100}
 101
 102static int gpio_ext_init(struct platform_device *pdev,
 103                         struct netxbig_gpio_ext *gpio_ext)
 104{
 105        int err;
 106        int i;
 107
 108        if (unlikely(!gpio_ext))
 109                return -EINVAL;
 110
 111        /* Configure address GPIOs. */
 112        for (i = 0; i < gpio_ext->num_addr; i++) {
 113                err = devm_gpio_request_one(&pdev->dev, gpio_ext->addr[i],
 114                                            GPIOF_OUT_INIT_LOW,
 115                                            "GPIO extension addr");
 116                if (err)
 117                        return err;
 118        }
 119        /* Configure data GPIOs. */
 120        for (i = 0; i < gpio_ext->num_data; i++) {
 121                err = devm_gpio_request_one(&pdev->dev, gpio_ext->data[i],
 122                                            GPIOF_OUT_INIT_LOW,
 123                                            "GPIO extension data");
 124                if (err)
 125                        return err;
 126        }
 127        /* Configure "enable select" GPIO. */
 128        err = devm_gpio_request_one(&pdev->dev, gpio_ext->enable,
 129                                    GPIOF_OUT_INIT_LOW,
 130                                    "GPIO extension enable");
 131        if (err)
 132                return err;
 133
 134        return 0;
 135}
 136
 137/*
 138 * Class LED driver.
 139 */
 140
 141struct netxbig_led_data {
 142        struct netxbig_gpio_ext *gpio_ext;
 143        struct led_classdev     cdev;
 144        int                     mode_addr;
 145        int                     *mode_val;
 146        int                     bright_addr;
 147        struct                  netxbig_led_timer *timer;
 148        int                     num_timer;
 149        enum netxbig_led_mode   mode;
 150        int                     sata;
 151        spinlock_t              lock;
 152};
 153
 154static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 155                                      unsigned long delay_on,
 156                                      unsigned long delay_off,
 157                                      struct netxbig_led_timer *timer,
 158                                      int num_timer)
 159{
 160        int i;
 161
 162        for (i = 0; i < num_timer; i++) {
 163                if (timer[i].delay_on == delay_on &&
 164                    timer[i].delay_off == delay_off) {
 165                        *mode = timer[i].mode;
 166                        return 0;
 167                }
 168        }
 169        return -EINVAL;
 170}
 171
 172static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 173                                 unsigned long *delay_on,
 174                                 unsigned long *delay_off)
 175{
 176        struct netxbig_led_data *led_dat =
 177                container_of(led_cdev, struct netxbig_led_data, cdev);
 178        enum netxbig_led_mode mode;
 179        int mode_val;
 180        int ret;
 181
 182        /* Look for a LED mode with the requested timer frequency. */
 183        ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 184                                         led_dat->timer, led_dat->num_timer);
 185        if (ret < 0)
 186                return ret;
 187
 188        mode_val = led_dat->mode_val[mode];
 189        if (mode_val == NETXBIG_LED_INVALID_MODE)
 190                return -EINVAL;
 191
 192        spin_lock_irq(&led_dat->lock);
 193
 194        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 195        led_dat->mode = mode;
 196
 197        spin_unlock_irq(&led_dat->lock);
 198
 199        return 0;
 200}
 201
 202static void netxbig_led_set(struct led_classdev *led_cdev,
 203                            enum led_brightness value)
 204{
 205        struct netxbig_led_data *led_dat =
 206                container_of(led_cdev, struct netxbig_led_data, cdev);
 207        enum netxbig_led_mode mode;
 208        int mode_val;
 209        int set_brightness = 1;
 210        unsigned long flags;
 211
 212        spin_lock_irqsave(&led_dat->lock, flags);
 213
 214        if (value == LED_OFF) {
 215                mode = NETXBIG_LED_OFF;
 216                set_brightness = 0;
 217        } else {
 218                if (led_dat->sata)
 219                        mode = NETXBIG_LED_SATA;
 220                else if (led_dat->mode == NETXBIG_LED_OFF)
 221                        mode = NETXBIG_LED_ON;
 222                else /* Keep 'timer' mode. */
 223                        mode = led_dat->mode;
 224        }
 225        mode_val = led_dat->mode_val[mode];
 226
 227        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 228        led_dat->mode = mode;
 229        /*
 230         * Note that the brightness register is shared between all the
 231         * SATA LEDs. So, change the brightness setting for a single
 232         * SATA LED will affect all the others.
 233         */
 234        if (set_brightness)
 235                gpio_ext_set_value(led_dat->gpio_ext,
 236                                   led_dat->bright_addr, value);
 237
 238        spin_unlock_irqrestore(&led_dat->lock, flags);
 239}
 240
 241static ssize_t netxbig_led_sata_store(struct device *dev,
 242                                      struct device_attribute *attr,
 243                                      const char *buff, size_t count)
 244{
 245        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 246        struct netxbig_led_data *led_dat =
 247                container_of(led_cdev, struct netxbig_led_data, cdev);
 248        unsigned long enable;
 249        enum netxbig_led_mode mode;
 250        int mode_val;
 251        int ret;
 252
 253        ret = kstrtoul(buff, 10, &enable);
 254        if (ret < 0)
 255                return ret;
 256
 257        enable = !!enable;
 258
 259        spin_lock_irq(&led_dat->lock);
 260
 261        if (led_dat->sata == enable) {
 262                ret = count;
 263                goto exit_unlock;
 264        }
 265
 266        if (led_dat->mode != NETXBIG_LED_ON &&
 267            led_dat->mode != NETXBIG_LED_SATA)
 268                mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 269        else if (enable)
 270                mode = NETXBIG_LED_SATA;
 271        else
 272                mode = NETXBIG_LED_ON;
 273
 274        mode_val = led_dat->mode_val[mode];
 275        if (mode_val == NETXBIG_LED_INVALID_MODE) {
 276                ret = -EINVAL;
 277                goto exit_unlock;
 278        }
 279
 280        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 281        led_dat->mode = mode;
 282        led_dat->sata = enable;
 283
 284        ret = count;
 285
 286exit_unlock:
 287        spin_unlock_irq(&led_dat->lock);
 288
 289        return ret;
 290}
 291
 292static ssize_t netxbig_led_sata_show(struct device *dev,
 293                                     struct device_attribute *attr, char *buf)
 294{
 295        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 296        struct netxbig_led_data *led_dat =
 297                container_of(led_cdev, struct netxbig_led_data, cdev);
 298
 299        return sprintf(buf, "%d\n", led_dat->sata);
 300}
 301
 302static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 303
 304static struct attribute *netxbig_led_attrs[] = {
 305        &dev_attr_sata.attr,
 306        NULL
 307};
 308ATTRIBUTE_GROUPS(netxbig_led);
 309
 310static int create_netxbig_led(struct platform_device *pdev,
 311                              struct netxbig_led_platform_data *pdata,
 312                              struct netxbig_led_data *led_dat,
 313                              const struct netxbig_led *template)
 314{
 315        spin_lock_init(&led_dat->lock);
 316        led_dat->gpio_ext = pdata->gpio_ext;
 317        led_dat->cdev.name = template->name;
 318        led_dat->cdev.default_trigger = template->default_trigger;
 319        led_dat->cdev.blink_set = netxbig_led_blink_set;
 320        led_dat->cdev.brightness_set = netxbig_led_set;
 321        /*
 322         * Because the GPIO extension bus don't allow to read registers
 323         * value, there is no way to probe the LED initial state.
 324         * So, the initial sysfs LED value for the "brightness" and "sata"
 325         * attributes are inconsistent.
 326         *
 327         * Note that the initial LED state can't be reconfigured.
 328         * The reason is that the LED behaviour must stay uniform during
 329         * the whole boot process (bootloader+linux).
 330         */
 331        led_dat->sata = 0;
 332        led_dat->cdev.brightness = LED_OFF;
 333        led_dat->cdev.max_brightness = template->bright_max;
 334        led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 335        led_dat->mode_addr = template->mode_addr;
 336        led_dat->mode_val = template->mode_val;
 337        led_dat->bright_addr = template->bright_addr;
 338        led_dat->timer = pdata->timer;
 339        led_dat->num_timer = pdata->num_timer;
 340        /*
 341         * If available, expose the SATA activity blink capability through
 342         * a "sata" sysfs attribute.
 343         */
 344        if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 345                led_dat->cdev.groups = netxbig_led_groups;
 346
 347        return devm_led_classdev_register(&pdev->dev, &led_dat->cdev);
 348}
 349
 350static int gpio_ext_get_of_pdata(struct device *dev, struct device_node *np,
 351                                 struct netxbig_gpio_ext *gpio_ext)
 352{
 353        int *addr, *data;
 354        int num_addr, num_data;
 355        int ret;
 356        int i;
 357
 358        ret = of_gpio_named_count(np, "addr-gpios");
 359        if (ret < 0) {
 360                dev_err(dev,
 361                        "Failed to count GPIOs in DT property addr-gpios\n");
 362                return ret;
 363        }
 364        num_addr = ret;
 365        addr = devm_kcalloc(dev, num_addr, sizeof(*addr), GFP_KERNEL);
 366        if (!addr)
 367                return -ENOMEM;
 368
 369        for (i = 0; i < num_addr; i++) {
 370                ret = of_get_named_gpio(np, "addr-gpios", i);
 371                if (ret < 0)
 372                        return ret;
 373                addr[i] = ret;
 374        }
 375        gpio_ext->addr = addr;
 376        gpio_ext->num_addr = num_addr;
 377
 378        ret = of_gpio_named_count(np, "data-gpios");
 379        if (ret < 0) {
 380                dev_err(dev,
 381                        "Failed to count GPIOs in DT property data-gpios\n");
 382                return ret;
 383        }
 384        num_data = ret;
 385        data = devm_kcalloc(dev, num_data, sizeof(*data), GFP_KERNEL);
 386        if (!data)
 387                return -ENOMEM;
 388
 389        for (i = 0; i < num_data; i++) {
 390                ret = of_get_named_gpio(np, "data-gpios", i);
 391                if (ret < 0)
 392                        return ret;
 393                data[i] = ret;
 394        }
 395        gpio_ext->data = data;
 396        gpio_ext->num_data = num_data;
 397
 398        ret = of_get_named_gpio(np, "enable-gpio", 0);
 399        if (ret < 0) {
 400                dev_err(dev,
 401                        "Failed to get GPIO from DT property enable-gpio\n");
 402                return ret;
 403        }
 404        gpio_ext->enable = ret;
 405
 406        return 0;
 407}
 408
 409static int netxbig_leds_get_of_pdata(struct device *dev,
 410                                     struct netxbig_led_platform_data *pdata)
 411{
 412        struct device_node *np = dev->of_node;
 413        struct device_node *gpio_ext_np;
 414        struct device_node *child;
 415        struct netxbig_gpio_ext *gpio_ext;
 416        struct netxbig_led_timer *timers;
 417        struct netxbig_led *leds, *led;
 418        int num_timers;
 419        int num_leds = 0;
 420        int ret;
 421        int i;
 422
 423        /* GPIO extension */
 424        gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
 425        if (!gpio_ext_np) {
 426                dev_err(dev, "Failed to get DT handle gpio-ext\n");
 427                return -EINVAL;
 428        }
 429
 430        gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
 431        if (!gpio_ext) {
 432                of_node_put(gpio_ext_np);
 433                return -ENOMEM;
 434        }
 435        ret = gpio_ext_get_of_pdata(dev, gpio_ext_np, gpio_ext);
 436        of_node_put(gpio_ext_np);
 437        if (ret)
 438                return ret;
 439        pdata->gpio_ext = gpio_ext;
 440
 441        /* Timers (optional) */
 442        ret = of_property_count_u32_elems(np, "timers");
 443        if (ret > 0) {
 444                if (ret % 3)
 445                        return -EINVAL;
 446                num_timers = ret / 3;
 447                timers = devm_kcalloc(dev, num_timers, sizeof(*timers),
 448                                      GFP_KERNEL);
 449                if (!timers)
 450                        return -ENOMEM;
 451                for (i = 0; i < num_timers; i++) {
 452                        u32 tmp;
 453
 454                        of_property_read_u32_index(np, "timers", 3 * i,
 455                                                   &timers[i].mode);
 456                        if (timers[i].mode >= NETXBIG_LED_MODE_NUM)
 457                                return -EINVAL;
 458                        of_property_read_u32_index(np, "timers",
 459                                                   3 * i + 1, &tmp);
 460                        timers[i].delay_on = tmp;
 461                        of_property_read_u32_index(np, "timers",
 462                                                   3 * i + 2, &tmp);
 463                        timers[i].delay_off = tmp;
 464                }
 465                pdata->timer = timers;
 466                pdata->num_timer = num_timers;
 467        }
 468
 469        /* LEDs */
 470        num_leds = of_get_child_count(np);
 471        if (!num_leds) {
 472                dev_err(dev, "No LED subnodes found in DT\n");
 473                return -ENODEV;
 474        }
 475
 476        leds = devm_kcalloc(dev, num_leds, sizeof(*leds), GFP_KERNEL);
 477        if (!leds)
 478                return -ENOMEM;
 479
 480        led = leds;
 481        for_each_child_of_node(np, child) {
 482                const char *string;
 483                int *mode_val;
 484                int num_modes;
 485
 486                ret = of_property_read_u32(child, "mode-addr",
 487                                           &led->mode_addr);
 488                if (ret)
 489                        goto err_node_put;
 490
 491                ret = of_property_read_u32(child, "bright-addr",
 492                                           &led->bright_addr);
 493                if (ret)
 494                        goto err_node_put;
 495
 496                ret = of_property_read_u32(child, "max-brightness",
 497                                           &led->bright_max);
 498                if (ret)
 499                        goto err_node_put;
 500
 501                mode_val =
 502                        devm_kcalloc(dev,
 503                                     NETXBIG_LED_MODE_NUM, sizeof(*mode_val),
 504                                     GFP_KERNEL);
 505                if (!mode_val) {
 506                        ret = -ENOMEM;
 507                        goto err_node_put;
 508                }
 509
 510                for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
 511                        mode_val[i] = NETXBIG_LED_INVALID_MODE;
 512
 513                ret = of_property_count_u32_elems(child, "mode-val");
 514                if (ret < 0 || ret % 2) {
 515                        ret = -EINVAL;
 516                        goto err_node_put;
 517                }
 518                num_modes = ret / 2;
 519                if (num_modes > NETXBIG_LED_MODE_NUM) {
 520                        ret = -EINVAL;
 521                        goto err_node_put;
 522                }
 523
 524                for (i = 0; i < num_modes; i++) {
 525                        int mode;
 526                        int val;
 527
 528                        of_property_read_u32_index(child,
 529                                                   "mode-val", 2 * i, &mode);
 530                        of_property_read_u32_index(child,
 531                                                   "mode-val", 2 * i + 1, &val);
 532                        if (mode >= NETXBIG_LED_MODE_NUM) {
 533                                ret = -EINVAL;
 534                                goto err_node_put;
 535                        }
 536                        mode_val[mode] = val;
 537                }
 538                led->mode_val = mode_val;
 539
 540                if (!of_property_read_string(child, "label", &string))
 541                        led->name = string;
 542                else
 543                        led->name = child->name;
 544
 545                if (!of_property_read_string(child,
 546                                             "linux,default-trigger", &string))
 547                        led->default_trigger = string;
 548
 549                led++;
 550        }
 551
 552        pdata->leds = leds;
 553        pdata->num_leds = num_leds;
 554
 555        return 0;
 556
 557err_node_put:
 558        of_node_put(child);
 559        return ret;
 560}
 561
 562static const struct of_device_id of_netxbig_leds_match[] = {
 563        { .compatible = "lacie,netxbig-leds", },
 564        {},
 565};
 566MODULE_DEVICE_TABLE(of, of_netxbig_leds_match);
 567
 568static int netxbig_led_probe(struct platform_device *pdev)
 569{
 570        struct netxbig_led_platform_data *pdata;
 571        struct netxbig_led_data *leds_data;
 572        int i;
 573        int ret;
 574
 575        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 576        if (!pdata)
 577                return -ENOMEM;
 578        ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
 579        if (ret)
 580                return ret;
 581
 582        leds_data = devm_kcalloc(&pdev->dev,
 583                                 pdata->num_leds, sizeof(*leds_data),
 584                                 GFP_KERNEL);
 585        if (!leds_data)
 586                return -ENOMEM;
 587
 588        ret = gpio_ext_init(pdev, pdata->gpio_ext);
 589        if (ret < 0)
 590                return ret;
 591
 592        for (i = 0; i < pdata->num_leds; i++) {
 593                ret = create_netxbig_led(pdev, pdata,
 594                                         &leds_data[i], &pdata->leds[i]);
 595                if (ret < 0)
 596                        return ret;
 597        }
 598
 599        return 0;
 600}
 601
 602static struct platform_driver netxbig_led_driver = {
 603        .probe          = netxbig_led_probe,
 604        .driver         = {
 605                .name           = "leds-netxbig",
 606                .of_match_table = of_netxbig_leds_match,
 607        },
 608};
 609
 610module_platform_driver(netxbig_led_driver);
 611
 612MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 613MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 614MODULE_LICENSE("GPL");
 615MODULE_ALIAS("platform:leds-netxbig");
 616