drivers/leds/leds-gpio.c

   1 /*
   2  * LEDs driver for GPIOs
   3  *
   4  * Copyright (C) 2007 8D Technologies inc.
   5  * Raphael Assenat <raph@8d.com>
   6  * Copyright (C) 2008 Freescale Semiconductor, Inc.
   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 version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/leds.h>
  17 #include <linux/workqueue.h>
  18
  19 #include <asm/gpio.h>
  20
  21 struct gpio_led_data {
  22         struct led_classdev cdev;
  23         unsigned gpio;
  24         struct work_struct work;
  25         u8 new_level;
  26         u8 can_sleep;
  27         u8 active_low;
  28         int (*platform_gpio_blink_set)(unsigned gpio,
  29                         unsigned long *delay_on, unsigned long *delay_off);
  30 };
  31
  32 static void gpio_led_work(struct work_struct *work)
  33 {
  34         struct gpio_led_data    *led_dat =
  35                 container_of(work, struct gpio_led_data, work);
  36
  37         gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
  38 }
  39
  40 static void gpio_led_set(struct led_classdev *led_cdev,
  41         enum led_brightness value)
  42 {
  43         struct gpio_led_data *led_dat =
  44                 container_of(led_cdev, struct gpio_led_data, cdev);
  45         int level;
  46
  47         if (value == LED_OFF)
  48                 level = 0;
  49         else
  50                 level = 1;
  51
  52         if (led_dat->active_low)
  53                 level = !level;
  54
  55         /* Setting GPIOs with I2C/etc requires a task context, and we don't
  56          * seem to have a reliable way to know if we're already in one; so
  57          * let's just assume the worst.
  58          */
  59         if (led_dat->can_sleep) {
  60                 led_dat->new_level = level;
  61                 schedule_work(&led_dat->work);
  62         } else
  63                 gpio_set_value(led_dat->gpio, level);
  64 }
  65
  66 static int gpio_blink_set(struct led_classdev *led_cdev,
  67         unsigned long *delay_on, unsigned long *delay_off)
  68 {
  69         struct gpio_led_data *led_dat =
  70                 container_of(led_cdev, struct gpio_led_data, cdev);
  71
  72         return led_dat->platform_gpio_blink_set(led_dat->gpio, delay_on, delay_off);
  73 }
  74
  75 static int __devinit create_gpio_led(const struct gpio_led *template,
  76         struct gpio_led_data *led_dat, struct device *parent,
  77         int (*blink_set)(unsigned, unsigned long *, unsigned long *))
  78 {
  79         int ret;
  80
  81         /* skip leds that aren't available */
  82         if (!gpio_is_valid(template->gpio)) {
  83                 printk(KERN_INFO "Skipping unavilable LED gpio %d (%s)\n",
  84                                 template->gpio, template->name);
  85                 return;
  86         }
  87
  88         ret = gpio_request(template->gpio, template->name);
  89         if (ret < 0)
  90                 return ret;
  91
  92         led_dat->cdev.name = template->name;
  93         led_dat->cdev.default_trigger = template->default_trigger;
  94         led_dat->gpio = template->gpio;
  95         led_dat->can_sleep = gpio_cansleep(template->gpio);
  96         led_dat->active_low = template->active_low;
  97         if (blink_set) {
  98                 led_dat->platform_gpio_blink_set = blink_set;
  99                 led_dat->cdev.blink_set = gpio_blink_set;
 100         }
 101         led_dat->cdev.brightness_set = gpio_led_set;
 102         led_dat->cdev.brightness = LED_OFF;
 103         if (!template->retain_state_suspended)
 104                 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 105
 106         ret = gpio_direction_output(led_dat->gpio, led_dat->active_low);
 107         if (ret < 0)
 108                 goto err;
 109
 110         INIT_WORK(&led_dat->work, gpio_led_work);
 111
 112         ret = led_classdev_register(parent, &led_dat->cdev);
 113         if (ret < 0)
 114                 goto err;
 115
 116         return 0;
 117 err:
 118         gpio_free(led_dat->gpio);
 119         return ret;
 120 }
 121
 122 static void delete_gpio_led(struct gpio_led_data *led)
 123 {
 124         if (!gpio_is_valid(led->gpio))
 125                 return;
 126         led_classdev_unregister(&led->cdev);
 127         cancel_work_sync(&led->work);
 128         gpio_free(led->gpio);
 129 }
 130
 131 #ifdef CONFIG_LEDS_GPIO_PLATFORM
 132 static int gpio_led_probe(struct platform_device *pdev)
 133 {
 134         struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
 135         struct gpio_led_data *leds_data;
 136         int i, ret = 0;
 137
 138         if (!pdata)
 139                 return -EBUSY;
 140
 141         leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
 142                                 GFP_KERNEL);
 143         if (!leds_data)
 144                 return -ENOMEM;
 145
 146         for (i = 0; i < pdata->num_leds; i++) {
 147                 ret = create_gpio_led(&pdata->leds[i], &leds_data[i],
 148                                       &pdev->dev, pdata->gpio_blink_set);
 149                 if (ret < 0)
 150                         goto err;
 151         }
 152
 153         platform_set_drvdata(pdev, leds_data);
 154
 155         return 0;
 156
 157 err:
 158         for (i = i - 1; i >= 0; i--)
 159                 delete_gpio_led(&leds_data[i]);
 160
 161         kfree(leds_data);
 162
 163         return ret;
 164 }
 165
 166 static int __devexit gpio_led_remove(struct platform_device *pdev)
 167 {
 168         int i;
 169         struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
 170         struct gpio_led_data *leds_data;
 171
 172         leds_data = platform_get_drvdata(pdev);
 173
 174         for (i = 0; i < pdata->num_leds; i++)
 175                 delete_gpio_led(&leds_data[i]);
 176
 177         kfree(leds_data);
 178
 179         return 0;
 180 }
 181
 182 static struct platform_driver gpio_led_driver = {
 183         .probe          = gpio_led_probe,
 184         .remove         = __devexit_p(gpio_led_remove),
 185         .driver         = {
 186                 .name   = "leds-gpio",
 187                 .owner  = THIS_MODULE,
 188         },
 189 };
 190
 191 MODULE_ALIAS("platform:leds-gpio");
 192 #endif /* CONFIG_LEDS_GPIO_PLATFORM */
 193
 194 /* Code to create from OpenFirmware platform devices */
 195 #ifdef CONFIG_LEDS_GPIO_OF
 196 #include <linux/of_platform.h>
 197 #include <linux/of_gpio.h>
 198
 199 struct gpio_led_of_platform_data {
 200         int num_leds;
 201         struct gpio_led_data led_data[];
 202 };
 203
 204 static int __devinit of_gpio_leds_probe(struct of_device *ofdev,
 205                                         const struct of_device_id *match)
 206 {
 207         struct device_node *np = ofdev->node, *child;
 208         struct gpio_led led;
 209         struct gpio_led_of_platform_data *pdata;
 210         int count = 0, ret;
 211
 212         /* count LEDs defined by this device, so we know how much to allocate */
 213         for_each_child_of_node(np, child)
 214                 count++;
 215         if (!count)
 216                 return 0; /* or ENODEV? */
 217
 218         pdata = kzalloc(sizeof(*pdata) + sizeof(struct gpio_led_data) * count,
 219                         GFP_KERNEL);
 220         if (!pdata)
 221                 return -ENOMEM;
 222
 223         memset(&led, 0, sizeof(led));
 224         for_each_child_of_node(np, child) {
 225                 enum of_gpio_flags flags;
 226
 227                 led.gpio = of_get_gpio_flags(child, 0, &flags);
 228                 led.active_low = flags & OF_GPIO_ACTIVE_LOW;
 229                 led.name = of_get_property(child, "label", NULL) ? : child->name;
 230                 led.default_trigger =
 231                         of_get_property(child, "linux,default-trigger", NULL);
 232
 233                 ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++],
 234                                       &ofdev->dev, NULL);
 235                 if (ret < 0) {
 236                         of_node_put(child);
 237                         goto err;
 238                 }
 239         }
 240
 241         dev_set_drvdata(&ofdev->dev, pdata);
 242
 243         return 0;
 244
 245 err:
 246         for (count = pdata->num_leds - 2; count >= 0; count--)
 247                 delete_gpio_led(&pdata->led_data[count]);
 248
 249         kfree(pdata);
 250
 251         return ret;
 252 }
 253
 254 static int __devexit of_gpio_leds_remove(struct of_device *ofdev)
 255 {
 256         struct gpio_led_of_platform_data *pdata = dev_get_drvdata(&ofdev->dev);
 257         int i;
 258
 259         for (i = 0; i < pdata->num_leds; i++)
 260                 delete_gpio_led(&pdata->led_data[i]);
 261
 262         kfree(pdata);
 263
 264         dev_set_drvdata(&ofdev->dev, NULL);
 265
 266         return 0;
 267 }
 268
 269 static const struct of_device_id of_gpio_leds_match[] = {
 270         { .compatible = "gpio-leds", },
 271         {},
 272 };
 273
 274 static struct of_platform_driver of_gpio_leds_driver = {
 275         .driver = {
 276                 .name = "of_gpio_leds",
 277                 .owner = THIS_MODULE,
 278         },
 279         .match_table = of_gpio_leds_match,
 280         .probe = of_gpio_leds_probe,
 281         .remove = __devexit_p(of_gpio_leds_remove),
 282 };
 283 #endif
 284
 285 static int __init gpio_led_init(void)
 286 {
 287         int ret;
 288
 289 #ifdef CONFIG_LEDS_GPIO_PLATFORM
 290         ret = platform_driver_register(&gpio_led_driver);
 291         if (ret)
 292                 return ret;
 293 #endif
 294 #ifdef CONFIG_LEDS_GPIO_OF
 295         ret = of_register_platform_driver(&of_gpio_leds_driver);
 296 #endif
 297 #ifdef CONFIG_LEDS_GPIO_PLATFORM
 298         if (ret)
 299                 platform_driver_unregister(&gpio_led_driver);
 300 #endif
 301
 302         return ret;
 303 }
 304
 305 static void __exit gpio_led_exit(void)
 306 {
 307 #ifdef CONFIG_LEDS_GPIO_PLATFORM
 308         platform_driver_unregister(&gpio_led_driver);
 309 #endif
 310 #ifdef CONFIG_LEDS_GPIO_OF
 311         of_unregister_platform_driver(&of_gpio_leds_driver);
 312 #endif
 313 }
 314
 315 module_init(gpio_led_init);
 316 module_exit(gpio_led_exit);
 317
 318 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
 319 MODULE_DESCRIPTION("GPIO LED driver");
 320 MODULE_LICENSE("GPL");