linux/drivers/leds/leds-netxbig.c
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   1/*
   2 * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
   3 *
   4 * Copyright (C) 2010 LaCie
   5 *
   6 * Author: Simon Guinot <sguinot@lacie.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21 */
  22
  23#include <linux/module.h>
  24#include <linux/irq.h>
  25#include <linux/slab.h>
  26#include <linux/spinlock.h>
  27#include <linux/platform_device.h>
  28#include <linux/gpio.h>
  29#include <linux/of_gpio.h>
  30#include <linux/leds.h>
  31#include <linux/platform_data/leds-kirkwood-netxbig.h>
  32
  33/*
  34 * GPIO extension bus.
  35 */
  36
  37static DEFINE_SPINLOCK(gpio_ext_lock);
  38
  39static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  40{
  41        int pin;
  42
  43        for (pin = 0; pin < gpio_ext->num_addr; pin++)
  44                gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  45}
  46
  47static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  48{
  49        int pin;
  50
  51        for (pin = 0; pin < gpio_ext->num_data; pin++)
  52                gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  53}
  54
  55static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  56{
  57        /* Enable select is done on the raising edge. */
  58        gpio_set_value(gpio_ext->enable, 0);
  59        gpio_set_value(gpio_ext->enable, 1);
  60}
  61
  62static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  63                               int addr, int value)
  64{
  65        unsigned long flags;
  66
  67        spin_lock_irqsave(&gpio_ext_lock, flags);
  68        gpio_ext_set_addr(gpio_ext, addr);
  69        gpio_ext_set_data(gpio_ext, value);
  70        gpio_ext_enable_select(gpio_ext);
  71        spin_unlock_irqrestore(&gpio_ext_lock, flags);
  72}
  73
  74static int gpio_ext_init(struct platform_device *pdev,
  75                         struct netxbig_gpio_ext *gpio_ext)
  76{
  77        int err;
  78        int i;
  79
  80        if (unlikely(!gpio_ext))
  81                return -EINVAL;
  82
  83        /* Configure address GPIOs. */
  84        for (i = 0; i < gpio_ext->num_addr; i++) {
  85                err = devm_gpio_request_one(&pdev->dev, gpio_ext->addr[i],
  86                                            GPIOF_OUT_INIT_LOW,
  87                                            "GPIO extension addr");
  88                if (err)
  89                        return err;
  90        }
  91        /* Configure data GPIOs. */
  92        for (i = 0; i < gpio_ext->num_data; i++) {
  93                err = devm_gpio_request_one(&pdev->dev, gpio_ext->data[i],
  94                                            GPIOF_OUT_INIT_LOW,
  95                                            "GPIO extension data");
  96                if (err)
  97                        return err;
  98        }
  99        /* Configure "enable select" GPIO. */
 100        err = devm_gpio_request_one(&pdev->dev, gpio_ext->enable,
 101                                    GPIOF_OUT_INIT_LOW,
 102                                    "GPIO extension enable");
 103        if (err)
 104                return err;
 105
 106        return 0;
 107}
 108
 109/*
 110 * Class LED driver.
 111 */
 112
 113struct netxbig_led_data {
 114        struct netxbig_gpio_ext *gpio_ext;
 115        struct led_classdev     cdev;
 116        int                     mode_addr;
 117        int                     *mode_val;
 118        int                     bright_addr;
 119        struct                  netxbig_led_timer *timer;
 120        int                     num_timer;
 121        enum netxbig_led_mode   mode;
 122        int                     sata;
 123        spinlock_t              lock;
 124};
 125
 126static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 127                                      unsigned long delay_on,
 128                                      unsigned long delay_off,
 129                                      struct netxbig_led_timer *timer,
 130                                      int num_timer)
 131{
 132        int i;
 133
 134        for (i = 0; i < num_timer; i++) {
 135                if (timer[i].delay_on == delay_on &&
 136                    timer[i].delay_off == delay_off) {
 137                        *mode = timer[i].mode;
 138                        return 0;
 139                }
 140        }
 141        return -EINVAL;
 142}
 143
 144static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 145                                 unsigned long *delay_on,
 146                                 unsigned long *delay_off)
 147{
 148        struct netxbig_led_data *led_dat =
 149                container_of(led_cdev, struct netxbig_led_data, cdev);
 150        enum netxbig_led_mode mode;
 151        int mode_val;
 152        int ret;
 153
 154        /* Look for a LED mode with the requested timer frequency. */
 155        ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 156                                         led_dat->timer, led_dat->num_timer);
 157        if (ret < 0)
 158                return ret;
 159
 160        mode_val = led_dat->mode_val[mode];
 161        if (mode_val == NETXBIG_LED_INVALID_MODE)
 162                return -EINVAL;
 163
 164        spin_lock_irq(&led_dat->lock);
 165
 166        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 167        led_dat->mode = mode;
 168
 169        spin_unlock_irq(&led_dat->lock);
 170
 171        return 0;
 172}
 173
 174static void netxbig_led_set(struct led_classdev *led_cdev,
 175                            enum led_brightness value)
 176{
 177        struct netxbig_led_data *led_dat =
 178                container_of(led_cdev, struct netxbig_led_data, cdev);
 179        enum netxbig_led_mode mode;
 180        int mode_val;
 181        int set_brightness = 1;
 182        unsigned long flags;
 183
 184        spin_lock_irqsave(&led_dat->lock, flags);
 185
 186        if (value == LED_OFF) {
 187                mode = NETXBIG_LED_OFF;
 188                set_brightness = 0;
 189        } else {
 190                if (led_dat->sata)
 191                        mode = NETXBIG_LED_SATA;
 192                else if (led_dat->mode == NETXBIG_LED_OFF)
 193                        mode = NETXBIG_LED_ON;
 194                else /* Keep 'timer' mode. */
 195                        mode = led_dat->mode;
 196        }
 197        mode_val = led_dat->mode_val[mode];
 198
 199        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 200        led_dat->mode = mode;
 201        /*
 202         * Note that the brightness register is shared between all the
 203         * SATA LEDs. So, change the brightness setting for a single
 204         * SATA LED will affect all the others.
 205         */
 206        if (set_brightness)
 207                gpio_ext_set_value(led_dat->gpio_ext,
 208                                   led_dat->bright_addr, value);
 209
 210        spin_unlock_irqrestore(&led_dat->lock, flags);
 211}
 212
 213static ssize_t netxbig_led_sata_store(struct device *dev,
 214                                      struct device_attribute *attr,
 215                                      const char *buff, size_t count)
 216{
 217        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 218        struct netxbig_led_data *led_dat =
 219                container_of(led_cdev, struct netxbig_led_data, cdev);
 220        unsigned long enable;
 221        enum netxbig_led_mode mode;
 222        int mode_val;
 223        int ret;
 224
 225        ret = kstrtoul(buff, 10, &enable);
 226        if (ret < 0)
 227                return ret;
 228
 229        enable = !!enable;
 230
 231        spin_lock_irq(&led_dat->lock);
 232
 233        if (led_dat->sata == enable) {
 234                ret = count;
 235                goto exit_unlock;
 236        }
 237
 238        if (led_dat->mode != NETXBIG_LED_ON &&
 239            led_dat->mode != NETXBIG_LED_SATA)
 240                mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 241        else if (enable)
 242                mode = NETXBIG_LED_SATA;
 243        else
 244                mode = NETXBIG_LED_ON;
 245
 246        mode_val = led_dat->mode_val[mode];
 247        if (mode_val == NETXBIG_LED_INVALID_MODE) {
 248                ret = -EINVAL;
 249                goto exit_unlock;
 250        }
 251
 252        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 253        led_dat->mode = mode;
 254        led_dat->sata = enable;
 255
 256        ret = count;
 257
 258exit_unlock:
 259        spin_unlock_irq(&led_dat->lock);
 260
 261        return ret;
 262}
 263
 264static ssize_t netxbig_led_sata_show(struct device *dev,
 265                                     struct device_attribute *attr, char *buf)
 266{
 267        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 268        struct netxbig_led_data *led_dat =
 269                container_of(led_cdev, struct netxbig_led_data, cdev);
 270
 271        return sprintf(buf, "%d\n", led_dat->sata);
 272}
 273
 274static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 275
 276static struct attribute *netxbig_led_attrs[] = {
 277        &dev_attr_sata.attr,
 278        NULL
 279};
 280ATTRIBUTE_GROUPS(netxbig_led);
 281
 282static int create_netxbig_led(struct platform_device *pdev,
 283                              struct netxbig_led_platform_data *pdata,
 284                              struct netxbig_led_data *led_dat,
 285                              const struct netxbig_led *template)
 286{
 287        spin_lock_init(&led_dat->lock);
 288        led_dat->gpio_ext = pdata->gpio_ext;
 289        led_dat->cdev.name = template->name;
 290        led_dat->cdev.default_trigger = template->default_trigger;
 291        led_dat->cdev.blink_set = netxbig_led_blink_set;
 292        led_dat->cdev.brightness_set = netxbig_led_set;
 293        /*
 294         * Because the GPIO extension bus don't allow to read registers
 295         * value, there is no way to probe the LED initial state.
 296         * So, the initial sysfs LED value for the "brightness" and "sata"
 297         * attributes are inconsistent.
 298         *
 299         * Note that the initial LED state can't be reconfigured.
 300         * The reason is that the LED behaviour must stay uniform during
 301         * the whole boot process (bootloader+linux).
 302         */
 303        led_dat->sata = 0;
 304        led_dat->cdev.brightness = LED_OFF;
 305        led_dat->cdev.max_brightness = template->bright_max;
 306        led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 307        led_dat->mode_addr = template->mode_addr;
 308        led_dat->mode_val = template->mode_val;
 309        led_dat->bright_addr = template->bright_addr;
 310        led_dat->timer = pdata->timer;
 311        led_dat->num_timer = pdata->num_timer;
 312        /*
 313         * If available, expose the SATA activity blink capability through
 314         * a "sata" sysfs attribute.
 315         */
 316        if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 317                led_dat->cdev.groups = netxbig_led_groups;
 318
 319        return devm_led_classdev_register(&pdev->dev, &led_dat->cdev);
 320}
 321
 322#ifdef CONFIG_OF_GPIO
 323static int gpio_ext_get_of_pdata(struct device *dev, struct device_node *np,
 324                                 struct netxbig_gpio_ext *gpio_ext)
 325{
 326        int *addr, *data;
 327        int num_addr, num_data;
 328        int ret;
 329        int i;
 330
 331        ret = of_gpio_named_count(np, "addr-gpios");
 332        if (ret < 0) {
 333                dev_err(dev,
 334                        "Failed to count GPIOs in DT property addr-gpios\n");
 335                return ret;
 336        }
 337        num_addr = ret;
 338        addr = devm_kzalloc(dev, num_addr * sizeof(*addr), GFP_KERNEL);
 339        if (!addr)
 340                return -ENOMEM;
 341
 342        for (i = 0; i < num_addr; i++) {
 343                ret = of_get_named_gpio(np, "addr-gpios", i);
 344                if (ret < 0)
 345                        return ret;
 346                addr[i] = ret;
 347        }
 348        gpio_ext->addr = addr;
 349        gpio_ext->num_addr = num_addr;
 350
 351        ret = of_gpio_named_count(np, "data-gpios");
 352        if (ret < 0) {
 353                dev_err(dev,
 354                        "Failed to count GPIOs in DT property data-gpios\n");
 355                return ret;
 356        }
 357        num_data = ret;
 358        data = devm_kzalloc(dev, num_data * sizeof(*data), GFP_KERNEL);
 359        if (!data)
 360                return -ENOMEM;
 361
 362        for (i = 0; i < num_data; i++) {
 363                ret = of_get_named_gpio(np, "data-gpios", i);
 364                if (ret < 0)
 365                        return ret;
 366                data[i] = ret;
 367        }
 368        gpio_ext->data = data;
 369        gpio_ext->num_data = num_data;
 370
 371        ret = of_get_named_gpio(np, "enable-gpio", 0);
 372        if (ret < 0) {
 373                dev_err(dev,
 374                        "Failed to get GPIO from DT property enable-gpio\n");
 375                return ret;
 376        }
 377        gpio_ext->enable = ret;
 378
 379        return 0;
 380}
 381
 382static int netxbig_leds_get_of_pdata(struct device *dev,
 383                                     struct netxbig_led_platform_data *pdata)
 384{
 385        struct device_node *np = dev->of_node;
 386        struct device_node *gpio_ext_np;
 387        struct device_node *child;
 388        struct netxbig_gpio_ext *gpio_ext;
 389        struct netxbig_led_timer *timers;
 390        struct netxbig_led *leds, *led;
 391        int num_timers;
 392        int num_leds = 0;
 393        int ret;
 394        int i;
 395
 396        /* GPIO extension */
 397        gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
 398        if (!gpio_ext_np) {
 399                dev_err(dev, "Failed to get DT handle gpio-ext\n");
 400                return -EINVAL;
 401        }
 402
 403        gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
 404        if (!gpio_ext)
 405                return -ENOMEM;
 406        ret = gpio_ext_get_of_pdata(dev, gpio_ext_np, gpio_ext);
 407        if (ret)
 408                return ret;
 409        of_node_put(gpio_ext_np);
 410        pdata->gpio_ext = gpio_ext;
 411
 412        /* Timers (optional) */
 413        ret = of_property_count_u32_elems(np, "timers");
 414        if (ret > 0) {
 415                if (ret % 3)
 416                        return -EINVAL;
 417                num_timers = ret / 3;
 418                timers = devm_kzalloc(dev, num_timers * sizeof(*timers),
 419                                      GFP_KERNEL);
 420                if (!timers)
 421                        return -ENOMEM;
 422                for (i = 0; i < num_timers; i++) {
 423                        u32 tmp;
 424
 425                        of_property_read_u32_index(np, "timers", 3 * i,
 426                                                   &timers[i].mode);
 427                        if (timers[i].mode >= NETXBIG_LED_MODE_NUM)
 428                                return -EINVAL;
 429                        of_property_read_u32_index(np, "timers",
 430                                                   3 * i + 1, &tmp);
 431                        timers[i].delay_on = tmp;
 432                        of_property_read_u32_index(np, "timers",
 433                                                   3 * i + 2, &tmp);
 434                        timers[i].delay_off = tmp;
 435                }
 436                pdata->timer = timers;
 437                pdata->num_timer = num_timers;
 438        }
 439
 440        /* LEDs */
 441        num_leds = of_get_child_count(np);
 442        if (!num_leds) {
 443                dev_err(dev, "No LED subnodes found in DT\n");
 444                return -ENODEV;
 445        }
 446
 447        leds = devm_kzalloc(dev, num_leds * sizeof(*leds), GFP_KERNEL);
 448        if (!leds)
 449                return -ENOMEM;
 450
 451        led = leds;
 452        for_each_child_of_node(np, child) {
 453                const char *string;
 454                int *mode_val;
 455                int num_modes;
 456
 457                ret = of_property_read_u32(child, "mode-addr",
 458                                           &led->mode_addr);
 459                if (ret)
 460                        goto err_node_put;
 461
 462                ret = of_property_read_u32(child, "bright-addr",
 463                                           &led->bright_addr);
 464                if (ret)
 465                        goto err_node_put;
 466
 467                ret = of_property_read_u32(child, "max-brightness",
 468                                           &led->bright_max);
 469                if (ret)
 470                        goto err_node_put;
 471
 472                mode_val =
 473                        devm_kzalloc(dev,
 474                                     NETXBIG_LED_MODE_NUM * sizeof(*mode_val),
 475                                     GFP_KERNEL);
 476                if (!mode_val) {
 477                        ret = -ENOMEM;
 478                        goto err_node_put;
 479                }
 480
 481                for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
 482                        mode_val[i] = NETXBIG_LED_INVALID_MODE;
 483
 484                ret = of_property_count_u32_elems(child, "mode-val");
 485                if (ret < 0 || ret % 2) {
 486                        ret = -EINVAL;
 487                        goto err_node_put;
 488                }
 489                num_modes = ret / 2;
 490                if (num_modes > NETXBIG_LED_MODE_NUM) {
 491                        ret = -EINVAL;
 492                        goto err_node_put;
 493                }
 494
 495                for (i = 0; i < num_modes; i++) {
 496                        int mode;
 497                        int val;
 498
 499                        of_property_read_u32_index(child,
 500                                                   "mode-val", 2 * i, &mode);
 501                        of_property_read_u32_index(child,
 502                                                   "mode-val", 2 * i + 1, &val);
 503                        if (mode >= NETXBIG_LED_MODE_NUM) {
 504                                ret = -EINVAL;
 505                                goto err_node_put;
 506                        }
 507                        mode_val[mode] = val;
 508                }
 509                led->mode_val = mode_val;
 510
 511                if (!of_property_read_string(child, "label", &string))
 512                        led->name = string;
 513                else
 514                        led->name = child->name;
 515
 516                if (!of_property_read_string(child,
 517                                             "linux,default-trigger", &string))
 518                        led->default_trigger = string;
 519
 520                led++;
 521        }
 522
 523        pdata->leds = leds;
 524        pdata->num_leds = num_leds;
 525
 526        return 0;
 527
 528err_node_put:
 529        of_node_put(child);
 530        return ret;
 531}
 532
 533static const struct of_device_id of_netxbig_leds_match[] = {
 534        { .compatible = "lacie,netxbig-leds", },
 535        {},
 536};
 537MODULE_DEVICE_TABLE(of, of_netxbig_leds_match);
 538#else
 539static inline int
 540netxbig_leds_get_of_pdata(struct device *dev,
 541                          struct netxbig_led_platform_data *pdata)
 542{
 543        return -ENODEV;
 544}
 545#endif /* CONFIG_OF_GPIO */
 546
 547static int netxbig_led_probe(struct platform_device *pdev)
 548{
 549        struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 550        struct netxbig_led_data *leds_data;
 551        int i;
 552        int ret;
 553
 554        if (!pdata) {
 555                pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 556                if (!pdata)
 557                        return -ENOMEM;
 558                ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
 559                if (ret)
 560                        return ret;
 561        }
 562
 563        leds_data = devm_kzalloc(&pdev->dev,
 564                                 pdata->num_leds * sizeof(*leds_data),
 565                                 GFP_KERNEL);
 566        if (!leds_data)
 567                return -ENOMEM;
 568
 569        ret = gpio_ext_init(pdev, pdata->gpio_ext);
 570        if (ret < 0)
 571                return ret;
 572
 573        for (i = 0; i < pdata->num_leds; i++) {
 574                ret = create_netxbig_led(pdev, pdata,
 575                                         &leds_data[i], &pdata->leds[i]);
 576                if (ret < 0)
 577                        return ret;
 578        }
 579
 580        return 0;
 581}
 582
 583static struct platform_driver netxbig_led_driver = {
 584        .probe          = netxbig_led_probe,
 585        .driver         = {
 586                .name           = "leds-netxbig",
 587                .of_match_table = of_match_ptr(of_netxbig_leds_match),
 588        },
 589};
 590
 591module_platform_driver(netxbig_led_driver);
 592
 593MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 594MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 595MODULE_LICENSE("GPL");
 596MODULE_ALIAS("platform:leds-netxbig");
 597