drivers/leds/leds-wm8350.c

   1 /*
   2  * LED driver for WM8350 driven LEDS.
   3  *
   4  * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/leds.h>
  15 #include <linux/err.h>
  16 #include <linux/mfd/wm8350/pmic.h>
  17 #include <linux/regulator/consumer.h>
  18 #include <linux/slab.h>
  19 #include <linux/module.h>
  20
  21 /* Microamps */
  22 static const int isink_cur[] = {
  23         4,
  24         5,
  25         6,
  26         7,
  27         8,
  28         10,
  29         11,
  30         14,
  31         16,
  32         19,
  33         23,
  34         27,
  35         32,
  36         39,
  37         46,
  38         54,
  39         65,
  40         77,
  41         92,
  42         109,
  43         130,
  44         154,
  45         183,
  46         218,
  47         259,
  48         308,
  49         367,
  50         436,
  51         518,
  52         616,
  53         733,
  54         872,
  55         1037,
  56         1233,
  57         1466,
  58         1744,
  59         2073,
  60         2466,
  61         2933,
  62         3487,
  63         4147,
  64         4932,
  65         5865,
  66         6975,
  67         8294,
  68         9864,
  69         11730,
  70         13949,
  71         16589,
  72         19728,
  73         23460,
  74         27899,
  75         33178,
  76         39455,
  77         46920,
  78         55798,
  79         66355,
  80         78910,
  81         93840,
  82         111596,
  83         132710,
  84         157820,
  85         187681,
  86         223191
  87 };
  88
  89 #define to_wm8350_led(led_cdev) \
  90         container_of(led_cdev, struct wm8350_led, cdev)
  91
  92 static int wm8350_led_enable(struct wm8350_led *led)
  93 {
  94         int ret = 0;
  95
  96         if (led->enabled)
  97                 return ret;
  98
  99         ret = regulator_enable(led->isink);
 100         if (ret != 0) {
 101                 dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
 102                 return ret;
 103         }
 104
 105         ret = regulator_enable(led->dcdc);
 106         if (ret != 0) {
 107                 dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
 108                 regulator_disable(led->isink);
 109                 return ret;
 110         }
 111
 112         led->enabled = 1;
 113
 114         return ret;
 115 }
 116
 117 static int wm8350_led_disable(struct wm8350_led *led)
 118 {
 119         int ret = 0;
 120
 121         if (!led->enabled)
 122                 return ret;
 123
 124         ret = regulator_disable(led->dcdc);
 125         if (ret != 0) {
 126                 dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
 127                 return ret;
 128         }
 129
 130         ret = regulator_disable(led->isink);
 131         if (ret != 0) {
 132                 dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
 133                 ret = regulator_enable(led->dcdc);
 134                 if (ret != 0)
 135                         dev_err(led->cdev.dev, "Failed to reenable DCDC: %d\n",
 136                                 ret);
 137                 return ret;
 138         }
 139
 140         led->enabled = 0;
 141
 142         return ret;
 143 }
 144
 145 static int wm8350_led_set(struct led_classdev *led_cdev,
 146                            enum led_brightness value)
 147 {
 148         struct wm8350_led *led = to_wm8350_led(led_cdev);
 149         unsigned long flags;
 150         int ret;
 151         int uA;
 152
 153         led->value = value;
 154
 155         spin_lock_irqsave(&led->value_lock, flags);
 156
 157         if (led->value == LED_OFF) {
 158                 spin_unlock_irqrestore(&led->value_lock, flags);
 159                 return wm8350_led_disable(led);
 160         }
 161
 162         /* This scales linearly into the index of valid current
 163          * settings which results in a linear scaling of perceived
 164          * brightness due to the non-linear current settings provided
 165          * by the hardware.
 166          */
 167         uA = (led->max_uA_index * led->value) / LED_FULL;
 168         spin_unlock_irqrestore(&led->value_lock, flags);
 169         BUG_ON(uA >= ARRAY_SIZE(isink_cur));
 170
 171         ret = regulator_set_current_limit(led->isink, isink_cur[uA],
 172                                           isink_cur[uA]);
 173         if (ret != 0) {
 174                 dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
 175                         isink_cur[uA], ret);
 176                 return ret;
 177         }
 178
 179         return wm8350_led_enable(led);
 180 }
 181
 182 static void wm8350_led_shutdown(struct platform_device *pdev)
 183 {
 184         struct wm8350_led *led = platform_get_drvdata(pdev);
 185
 186         led->value = LED_OFF;
 187         wm8350_led_disable(led);
 188 }
 189
 190 static int wm8350_led_probe(struct platform_device *pdev)
 191 {
 192         struct regulator *isink, *dcdc;
 193         struct wm8350_led *led;
 194         struct wm8350_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 195         int i;
 196
 197         if (pdata == NULL) {
 198                 dev_err(&pdev->dev, "no platform data\n");
 199                 return -ENODEV;
 200         }
 201
 202         if (pdata->max_uA < isink_cur[0]) {
 203                 dev_err(&pdev->dev, "Invalid maximum current %duA\n",
 204                         pdata->max_uA);
 205                 return -EINVAL;
 206         }
 207
 208         isink = devm_regulator_get(&pdev->dev, "led_isink");
 209         if (IS_ERR(isink)) {
 210                 dev_err(&pdev->dev, "%s: can't get ISINK\n", __func__);
 211                 return PTR_ERR(isink);
 212         }
 213
 214         dcdc = devm_regulator_get(&pdev->dev, "led_vcc");
 215         if (IS_ERR(dcdc)) {
 216                 dev_err(&pdev->dev, "%s: can't get DCDC\n", __func__);
 217                 return PTR_ERR(dcdc);
 218         }
 219
 220         led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
 221         if (led == NULL)
 222                 return -ENOMEM;
 223
 224         led->cdev.brightness_set_blocking = wm8350_led_set;
 225         led->cdev.default_trigger = pdata->default_trigger;
 226         led->cdev.name = pdata->name;
 227         led->cdev.flags |= LED_CORE_SUSPENDRESUME;
 228         led->enabled = regulator_is_enabled(isink);
 229         led->isink = isink;
 230         led->dcdc = dcdc;
 231
 232         for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
 233                 if (isink_cur[i] >= pdata->max_uA)
 234                         break;
 235         led->max_uA_index = i;
 236         if (pdata->max_uA != isink_cur[i])
 237                 dev_warn(&pdev->dev,
 238                          "Maximum current %duA is not directly supported,"
 239                          " check platform data\n",
 240                          pdata->max_uA);
 241
 242         spin_lock_init(&led->value_lock);
 243         led->value = LED_OFF;
 244         platform_set_drvdata(pdev, led);
 245
 246         return led_classdev_register(&pdev->dev, &led->cdev);
 247 }
 248
 249 static int wm8350_led_remove(struct platform_device *pdev)
 250 {
 251         struct wm8350_led *led = platform_get_drvdata(pdev);
 252
 253         led_classdev_unregister(&led->cdev);
 254         wm8350_led_disable(led);
 255         return 0;
 256 }
 257
 258 static struct platform_driver wm8350_led_driver = {
 259         .driver = {
 260                    .name = "wm8350-led",
 261                    },
 262         .probe = wm8350_led_probe,
 263         .remove = wm8350_led_remove,
 264         .shutdown = wm8350_led_shutdown,
 265 };
 266
 267 module_platform_driver(wm8350_led_driver);
 268
 269 MODULE_AUTHOR("Mark Brown");
 270 MODULE_DESCRIPTION("WM8350 LED driver");
 271 MODULE_LICENSE("GPL");
 272 MODULE_ALIAS("platform:wm8350-led");