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/init.h>
  25#include <linux/irq.h>
  26#include <linux/slab.h>
  27#include <linux/spinlock.h>
  28#include <linux/platform_device.h>
  29#include <linux/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 __devinit gpio_ext_init(struct netxbig_gpio_ext *gpio_ext)
  75{
  76        int err;
  77        int i;
  78
  79        if (unlikely(!gpio_ext))
  80                return -EINVAL;
  81
  82        /* Configure address GPIOs. */
  83        for (i = 0; i < gpio_ext->num_addr; i++) {
  84                err = gpio_request_one(gpio_ext->addr[i], GPIOF_OUT_INIT_LOW,
  85                                       "GPIO extension addr");
  86                if (err)
  87                        goto err_free_addr;
  88        }
  89        /* Configure data GPIOs. */
  90        for (i = 0; i < gpio_ext->num_data; i++) {
  91                err = gpio_request_one(gpio_ext->data[i], GPIOF_OUT_INIT_LOW,
  92                                   "GPIO extension data");
  93                if (err)
  94                        goto err_free_data;
  95        }
  96        /* Configure "enable select" GPIO. */
  97        err = gpio_request_one(gpio_ext->enable, GPIOF_OUT_INIT_LOW,
  98                               "GPIO extension enable");
  99        if (err)
 100                goto err_free_data;
 101
 102        return 0;
 103
 104err_free_data:
 105        for (i = i - 1; i >= 0; i--)
 106                gpio_free(gpio_ext->data[i]);
 107        i = gpio_ext->num_addr;
 108err_free_addr:
 109        for (i = i - 1; i >= 0; i--)
 110                gpio_free(gpio_ext->addr[i]);
 111
 112        return err;
 113}
 114
 115static void gpio_ext_free(struct netxbig_gpio_ext *gpio_ext)
 116{
 117        int i;
 118
 119        gpio_free(gpio_ext->enable);
 120        for (i = gpio_ext->num_addr - 1; i >= 0; i--)
 121                gpio_free(gpio_ext->addr[i]);
 122        for (i = gpio_ext->num_data - 1; i >= 0; i--)
 123                gpio_free(gpio_ext->data[i]);
 124}
 125
 126/*
 127 * Class LED driver.
 128 */
 129
 130struct netxbig_led_data {
 131        struct netxbig_gpio_ext *gpio_ext;
 132        struct led_classdev     cdev;
 133        int                     mode_addr;
 134        int                     *mode_val;
 135        int                     bright_addr;
 136        int                     bright_max;
 137        struct                  netxbig_led_timer *timer;
 138        int                     num_timer;
 139        enum netxbig_led_mode   mode;
 140        int                     sata;
 141        spinlock_t              lock;
 142};
 143
 144static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 145                                      unsigned long delay_on,
 146                                      unsigned long delay_off,
 147                                      struct netxbig_led_timer *timer,
 148                                      int num_timer)
 149{
 150        int i;
 151
 152        for (i = 0; i < num_timer; i++) {
 153                if (timer[i].delay_on == delay_on &&
 154                    timer[i].delay_off == delay_off) {
 155                        *mode = timer[i].mode;
 156                        return 0;
 157                }
 158        }
 159        return -EINVAL;
 160}
 161
 162static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 163                                 unsigned long *delay_on,
 164                                 unsigned long *delay_off)
 165{
 166        struct netxbig_led_data *led_dat =
 167                container_of(led_cdev, struct netxbig_led_data, cdev);
 168        enum netxbig_led_mode mode;
 169        int mode_val;
 170        int ret;
 171
 172        /* Look for a LED mode with the requested timer frequency. */
 173        ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 174                                         led_dat->timer, led_dat->num_timer);
 175        if (ret < 0)
 176                return ret;
 177
 178        mode_val = led_dat->mode_val[mode];
 179        if (mode_val == NETXBIG_LED_INVALID_MODE)
 180                return -EINVAL;
 181
 182        spin_lock_irq(&led_dat->lock);
 183
 184        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 185        led_dat->mode = mode;
 186
 187        spin_unlock_irq(&led_dat->lock);
 188
 189        return 0;
 190}
 191
 192static void netxbig_led_set(struct led_classdev *led_cdev,
 193                            enum led_brightness value)
 194{
 195        struct netxbig_led_data *led_dat =
 196                container_of(led_cdev, struct netxbig_led_data, cdev);
 197        enum netxbig_led_mode mode;
 198        int mode_val, bright_val;
 199        int set_brightness = 1;
 200        unsigned long flags;
 201
 202        spin_lock_irqsave(&led_dat->lock, flags);
 203
 204        if (value == LED_OFF) {
 205                mode = NETXBIG_LED_OFF;
 206                set_brightness = 0;
 207        } else {
 208                if (led_dat->sata)
 209                        mode = NETXBIG_LED_SATA;
 210                else if (led_dat->mode == NETXBIG_LED_OFF)
 211                        mode = NETXBIG_LED_ON;
 212                else /* Keep 'timer' mode. */
 213                        mode = led_dat->mode;
 214        }
 215        mode_val = led_dat->mode_val[mode];
 216
 217        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 218        led_dat->mode = mode;
 219        /*
 220         * Note that the brightness register is shared between all the
 221         * SATA LEDs. So, change the brightness setting for a single
 222         * SATA LED will affect all the others.
 223         */
 224        if (set_brightness) {
 225                bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
 226                                          LED_FULL);
 227                gpio_ext_set_value(led_dat->gpio_ext,
 228                                   led_dat->bright_addr, bright_val);
 229        }
 230
 231        spin_unlock_irqrestore(&led_dat->lock, flags);
 232}
 233
 234static ssize_t netxbig_led_sata_store(struct device *dev,
 235                                      struct device_attribute *attr,
 236                                      const char *buff, size_t count)
 237{
 238        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 239        struct netxbig_led_data *led_dat =
 240                container_of(led_cdev, struct netxbig_led_data, cdev);
 241        unsigned long enable;
 242        enum netxbig_led_mode mode;
 243        int mode_val;
 244        int ret;
 245
 246        ret = strict_strtoul(buff, 10, &enable);
 247        if (ret < 0)
 248                return ret;
 249
 250        enable = !!enable;
 251
 252        spin_lock_irq(&led_dat->lock);
 253
 254        if (led_dat->sata == enable) {
 255                ret = count;
 256                goto exit_unlock;
 257        }
 258
 259        if (led_dat->mode != NETXBIG_LED_ON &&
 260            led_dat->mode != NETXBIG_LED_SATA)
 261                mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 262        else if (enable)
 263                mode = NETXBIG_LED_SATA;
 264        else
 265                mode = NETXBIG_LED_ON;
 266
 267        mode_val = led_dat->mode_val[mode];
 268        if (mode_val == NETXBIG_LED_INVALID_MODE) {
 269                ret = -EINVAL;
 270                goto exit_unlock;
 271        }
 272
 273        gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 274        led_dat->mode = mode;
 275        led_dat->sata = enable;
 276
 277        ret = count;
 278
 279exit_unlock:
 280        spin_unlock_irq(&led_dat->lock);
 281
 282        return ret;
 283}
 284
 285static ssize_t netxbig_led_sata_show(struct device *dev,
 286                                     struct device_attribute *attr, char *buf)
 287{
 288        struct led_classdev *led_cdev = dev_get_drvdata(dev);
 289        struct netxbig_led_data *led_dat =
 290                container_of(led_cdev, struct netxbig_led_data, cdev);
 291
 292        return sprintf(buf, "%d\n", led_dat->sata);
 293}
 294
 295static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 296
 297static void delete_netxbig_led(struct netxbig_led_data *led_dat)
 298{
 299        if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 300                device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 301        led_classdev_unregister(&led_dat->cdev);
 302}
 303
 304static int __devinit
 305create_netxbig_led(struct platform_device *pdev,
 306                   struct netxbig_led_data *led_dat,
 307                   const struct netxbig_led *template)
 308{
 309        struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 310        int ret;
 311
 312        spin_lock_init(&led_dat->lock);
 313        led_dat->gpio_ext = pdata->gpio_ext;
 314        led_dat->cdev.name = template->name;
 315        led_dat->cdev.default_trigger = template->default_trigger;
 316        led_dat->cdev.blink_set = netxbig_led_blink_set;
 317        led_dat->cdev.brightness_set = netxbig_led_set;
 318        /*
 319         * Because the GPIO extension bus don't allow to read registers
 320         * value, there is no way to probe the LED initial state.
 321         * So, the initial sysfs LED value for the "brightness" and "sata"
 322         * attributes are inconsistent.
 323         *
 324         * Note that the initial LED state can't be reconfigured.
 325         * The reason is that the LED behaviour must stay uniform during
 326         * the whole boot process (bootloader+linux).
 327         */
 328        led_dat->sata = 0;
 329        led_dat->cdev.brightness = LED_OFF;
 330        led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 331        led_dat->mode_addr = template->mode_addr;
 332        led_dat->mode_val = template->mode_val;
 333        led_dat->bright_addr = template->bright_addr;
 334        led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
 335        led_dat->timer = pdata->timer;
 336        led_dat->num_timer = pdata->num_timer;
 337
 338        ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 339        if (ret < 0)
 340                return ret;
 341
 342        /*
 343         * If available, expose the SATA activity blink capability through
 344         * a "sata" sysfs attribute.
 345         */
 346        if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE) {
 347                ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
 348                if (ret)
 349                        led_classdev_unregister(&led_dat->cdev);
 350        }
 351
 352        return ret;
 353}
 354
 355static int __devinit netxbig_led_probe(struct platform_device *pdev)
 356{
 357        struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 358        struct netxbig_led_data *leds_data;
 359        int i;
 360        int ret;
 361
 362        if (!pdata)
 363                return -EINVAL;
 364
 365        leds_data = devm_kzalloc(&pdev->dev,
 366                sizeof(struct netxbig_led_data) * pdata->num_leds, GFP_KERNEL);
 367        if (!leds_data)
 368                return -ENOMEM;
 369
 370        ret = gpio_ext_init(pdata->gpio_ext);
 371        if (ret < 0)
 372                return ret;
 373
 374        for (i = 0; i < pdata->num_leds; i++) {
 375                ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
 376                if (ret < 0)
 377                        goto err_free_leds;
 378        }
 379
 380        platform_set_drvdata(pdev, leds_data);
 381
 382        return 0;
 383
 384err_free_leds:
 385        for (i = i - 1; i >= 0; i--)
 386                delete_netxbig_led(&leds_data[i]);
 387
 388        gpio_ext_free(pdata->gpio_ext);
 389        return ret;
 390}
 391
 392static int __devexit netxbig_led_remove(struct platform_device *pdev)
 393{
 394        struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 395        struct netxbig_led_data *leds_data;
 396        int i;
 397
 398        leds_data = platform_get_drvdata(pdev);
 399
 400        for (i = 0; i < pdata->num_leds; i++)
 401                delete_netxbig_led(&leds_data[i]);
 402
 403        gpio_ext_free(pdata->gpio_ext);
 404
 405        return 0;
 406}
 407
 408static struct platform_driver netxbig_led_driver = {
 409        .probe          = netxbig_led_probe,
 410        .remove         = __devexit_p(netxbig_led_remove),
 411        .driver         = {
 412                .name   = "leds-netxbig",
 413                .owner  = THIS_MODULE,
 414        },
 415};
 416
 417module_platform_driver(netxbig_led_driver);
 418
 419MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 420MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 421MODULE_LICENSE("GPL");
 422MODULE_ALIAS("platform:leds-netxbig");
 423
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