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/leds.h>
  30#include <linux/platform_data/leds-kirkwood-netxbig.h>
  31
  32/*
  33 * GPIO extension bus.
  34 */
  35
  36static DEFINE_SPINLOCK(gpio_ext_lock);
  37
  38static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  39{
  40        int pin;
  41
  42        for (pin = 0; pin < gpio_ext->num_addr; pin++)
  43                gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  44}
  45
  46static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  47{
  48        int pin;
  49
  50        for (pin = 0; pin < gpio_ext->num_data; pin++)
  51                gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  52}
  53
  54static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  55{
  56        /* Enable select is done on the raising edge. */
  57        gpio_set_value(gpio_ext->enable, 0);
  58        gpio_set_value(gpio_ext->enable, 1);
  59}
  60
  61static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  62                               int addr, int value)
  63{
  64        unsigned long flags;
  65
  66        spin_lock_irqsave(&gpio_ext_lock, flags);
  67        gpio_ext_set_addr(gpio_ext, addr);
  68        gpio_ext_set_data(gpio_ext, value);
  69        gpio_ext_enable_select(gpio_ext);
  70        spin_unlock_irqrestore(&gpio_ext_lock, flags);
  71}
  72
  73static int gpio_ext_init(struct netxbig_gpio_ext *gpio_ext)
  74{
  75        int err;
  76        int i;
  77
  78        if (unlikely(!gpio_ext))
  79                return -EINVAL;
  80
  81        /* Configure address GPIOs. */
  82        for (i = 0; i < gpio_ext->num_addr; i++) {
  83                err = gpio_request_one(gpio_ext->addr[i], GPIOF_OUT_INIT_LOW,
  84                                       "GPIO extension addr");
  85                if (err)
  86                        goto err_free_addr;
  87        }
  88        /* Configure data GPIOs. */
  89        for (i = 0; i < gpio_ext->num_data; i++) {
  90                err = gpio_request_one(gpio_ext->data[i], GPIOF_OUT_INIT_LOW,
  91                                   "GPIO extension data");
  92                if (err)
  93                        goto err_free_data;
  94        }
  95        /* Configure "enable select" GPIO. */
  96        err = gpio_request_one(gpio_ext->enable, GPIOF_OUT_INIT_LOW,
  97                               "GPIO extension enable");
  98        if (err)
  99                goto err_free_data;
 100
 101        return 0;
 102
 103err_free_data:
 104        for (i = i - 1; i >= 0; i--)
 105                gpio_free(gpio_ext->data[i]);
 106        i = gpio_ext->num_addr;
 107err_free_addr:
 108        for (i = i - 1; i >= 0; i--)
 109                gpio_free(gpio_ext->addr[i]);
 110
 111        return err;
 112}
 113
 114static void gpio_ext_free(struct netxbig_gpio_ext *gpio_ext)
 115{
 116        int i;
 117
 118        gpio_free(gpio_ext->enable);
 119        for (i = gpio_ext->num_addr - 1; i >= 0; i--)
 120                gpio_free(gpio_ext->addr[i]);
 121        for (i = gpio_ext->num_data - 1; i >= 0; i--)
 122                gpio_free(gpio_ext->data[i]);
 123}
 124
 125/*
 126 * Class LED driver.
 127 */
 128
 129struct netxbig_led_data {
 130        struct netxbig_gpio_ext *gpio_ext;
 131        struct led_classdev     cdev;
 132        int                     mode_addr;
 133        int                     *mode_val;
 134        int                     bright_addr;
 135        int                     bright_max;
 136        struct                  netxbig_led_timer *timer;
 137        int                     num_timer;
 138        enum netxbig_led_mode   mode;
 139        int                     sata;
 140        spinlock_t              lock;
 141};
 142
 143static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 144                                      unsigned long delay_on,
 145                                      unsigned long delay_off,
 146                                      struct netxbig_led_timer *timer,
 147                                      int num_timer)
 148{
 149        int i;
 150
 151        for (i = 0; i < num_timer; i++) {
 152                if (timer[i].delay_on == delay_on &&
 153                    timer[i].delay_off == delay_off) {
 154                        *mode = timer[i].mode;
 155                        return 0;
 156                }
 157        }
 158        return -EINVAL;
 159}
 160
 161static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 162                                 unsigned long *delay_on,
 163                                 unsigned long *delay_off)
 164{
 165        struct netxbig_led_data *led_dat =
 166                container_of(led_cdev, struct netxbig_led_data, cdev);
 167        enum netxbig_led_mode mode;
 168        int mode_val;
 169        int ret;
 170
 171        /* Look for a LED mode with the requested timer frequency. */
 172        ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 173                                         led_dat->timer, led_dat->num_timer);
 174        if (ret < 0)
 175                return ret;
 176
 177        mode_val = led_dat->mode_val[mode];
 178        if (mode_val == NETXBIG_LED_INVALID_MODE)
 179                return -EINVAL;
 180
 181        spin_lock_irq(&led_dat->lock);
 182
 183        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 184        led_dat->mode = mode;
 185
 186        spin_unlock_irq(&led_dat->lock);
 187
 188        return 0;
 189}
 190
 191static void netxbig_led_set(struct led_classdev *led_cdev,
 192                            enum led_brightness value)
 193{
 194        struct netxbig_led_data *led_dat =
 195                container_of(led_cdev, struct netxbig_led_data, cdev);
 196        enum netxbig_led_mode mode;
 197        int mode_val, bright_val;
 198        int set_brightness = 1;
 199        unsigned long flags;
 200
 201        spin_lock_irqsave(&led_dat->lock, flags);
 202
 203        if (value == LED_OFF) {
 204                mode = NETXBIG_LED_OFF;
 205                set_brightness = 0;
 206        } else {
 207                if (led_dat->sata)
 208                        mode = NETXBIG_LED_SATA;
 209                else if (led_dat->mode == NETXBIG_LED_OFF)
 210                        mode = NETXBIG_LED_ON;
 211                else /* Keep 'timer' mode. */
 212                        mode = led_dat->mode;
 213        }
 214        mode_val = led_dat->mode_val[mode];
 215
 216        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 217        led_dat->mode = mode;
 218        /*
 219         * Note that the brightness register is shared between all the
 220         * SATA LEDs. So, change the brightness setting for a single
 221         * SATA LED will affect all the others.
 222         */
 223        if (set_brightness) {
 224                bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
 225                                          LED_FULL);
 226                gpio_ext_set_value(led_dat->gpio_ext,
 227                                   led_dat->bright_addr, bright_val);
 228        }
 229
 230        spin_unlock_irqrestore(&led_dat->lock, flags);
 231}
 232
 233static ssize_t netxbig_led_sata_store(struct device *dev,
 234                                      struct device_attribute *attr,
 235                                      const char *buff, size_t count)
 236{
 237        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 238        struct netxbig_led_data *led_dat =
 239                container_of(led_cdev, struct netxbig_led_data, cdev);
 240        unsigned long enable;
 241        enum netxbig_led_mode mode;
 242        int mode_val;
 243        int ret;
 244
 245        ret = kstrtoul(buff, 10, &enable);
 246        if (ret < 0)
 247                return ret;
 248
 249        enable = !!enable;
 250
 251        spin_lock_irq(&led_dat->lock);
 252
 253        if (led_dat->sata == enable) {
 254                ret = count;
 255                goto exit_unlock;
 256        }
 257
 258        if (led_dat->mode != NETXBIG_LED_ON &&
 259            led_dat->mode != NETXBIG_LED_SATA)
 260                mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 261        else if (enable)
 262                mode = NETXBIG_LED_SATA;
 263        else
 264                mode = NETXBIG_LED_ON;
 265
 266        mode_val = led_dat->mode_val[mode];
 267        if (mode_val == NETXBIG_LED_INVALID_MODE) {
 268                ret = -EINVAL;
 269                goto exit_unlock;
 270        }
 271
 272        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 273        led_dat->mode = mode;
 274        led_dat->sata = enable;
 275
 276        ret = count;
 277
 278exit_unlock:
 279        spin_unlock_irq(&led_dat->lock);
 280
 281        return ret;
 282}
 283
 284static ssize_t netxbig_led_sata_show(struct device *dev,
 285                                     struct device_attribute *attr, char *buf)
 286{
 287        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 288        struct netxbig_led_data *led_dat =
 289                container_of(led_cdev, struct netxbig_led_data, cdev);
 290
 291        return sprintf(buf, "%d\n", led_dat->sata);
 292}
 293
 294static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 295
 296static struct attribute *netxbig_led_attrs[] = {
 297        &dev_attr_sata.attr,
 298        NULL
 299};
 300ATTRIBUTE_GROUPS(netxbig_led);
 301
 302static void delete_netxbig_led(struct netxbig_led_data *led_dat)
 303{
 304        led_classdev_unregister(&led_dat->cdev);
 305}
 306
 307static int
 308create_netxbig_led(struct platform_device *pdev,
 309                   struct netxbig_led_data *led_dat,
 310                   const struct netxbig_led *template)
 311{
 312        struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 313
 314        spin_lock_init(&led_dat->lock);
 315        led_dat->gpio_ext = pdata->gpio_ext;
 316        led_dat->cdev.name = template->name;
 317        led_dat->cdev.default_trigger = template->default_trigger;
 318        led_dat->cdev.blink_set = netxbig_led_blink_set;
 319        led_dat->cdev.brightness_set = netxbig_led_set;
 320        /*
 321         * Because the GPIO extension bus don't allow to read registers
 322         * value, there is no way to probe the LED initial state.
 323         * So, the initial sysfs LED value for the "brightness" and "sata"
 324         * attributes are inconsistent.
 325         *
 326         * Note that the initial LED state can't be reconfigured.
 327         * The reason is that the LED behaviour must stay uniform during
 328         * the whole boot process (bootloader+linux).
 329         */
 330        led_dat->sata = 0;
 331        led_dat->cdev.brightness = LED_OFF;
 332        led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 333        led_dat->mode_addr = template->mode_addr;
 334        led_dat->mode_val = template->mode_val;
 335        led_dat->bright_addr = template->bright_addr;
 336        led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
 337        led_dat->timer = pdata->timer;
 338        led_dat->num_timer = pdata->num_timer;
 339        /*
 340         * If available, expose the SATA activity blink capability through
 341         * a "sata" sysfs attribute.
 342         */
 343        if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 344                led_dat->cdev.groups = netxbig_led_groups;
 345
 346        return led_classdev_register(&pdev->dev, &led_dat->cdev);
 347}
 348
 349static int netxbig_led_probe(struct platform_device *pdev)
 350{
 351        struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 352        struct netxbig_led_data *leds_data;
 353        int i;
 354        int ret;
 355
 356        if (!pdata)
 357                return -EINVAL;
 358
 359        leds_data = devm_kzalloc(&pdev->dev,
 360                sizeof(struct netxbig_led_data) * pdata->num_leds, GFP_KERNEL);
 361        if (!leds_data)
 362                return -ENOMEM;
 363
 364        ret = gpio_ext_init(pdata->gpio_ext);
 365        if (ret < 0)
 366                return ret;
 367
 368        for (i = 0; i < pdata->num_leds; i++) {
 369                ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
 370                if (ret < 0)
 371                        goto err_free_leds;
 372        }
 373
 374        platform_set_drvdata(pdev, leds_data);
 375
 376        return 0;
 377
 378err_free_leds:
 379        for (i = i - 1; i >= 0; i--)
 380                delete_netxbig_led(&leds_data[i]);
 381
 382        gpio_ext_free(pdata->gpio_ext);
 383        return ret;
 384}
 385
 386static int netxbig_led_remove(struct platform_device *pdev)
 387{
 388        struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 389        struct netxbig_led_data *leds_data;
 390        int i;
 391
 392        leds_data = platform_get_drvdata(pdev);
 393
 394        for (i = 0; i < pdata->num_leds; i++)
 395                delete_netxbig_led(&leds_data[i]);
 396
 397        gpio_ext_free(pdata->gpio_ext);
 398
 399        return 0;
 400}
 401
 402static struct platform_driver netxbig_led_driver = {
 403        .probe          = netxbig_led_probe,
 404        .remove         = netxbig_led_remove,
 405        .driver         = {
 406                .name   = "leds-netxbig",
 407        },
 408};
 409
 410module_platform_driver(netxbig_led_driver);
 411
 412MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 413MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 414MODULE_LICENSE("GPL");
 415MODULE_ALIAS("platform:leds-netxbig");
 416