drivers/leds/leds-lp8788.c

   1 /*
   2  * TI LP8788 MFD - keyled driver
   3  *
   4  * Copyright 2012 Texas Instruments
   5  *
   6  * Author: Milo(Woogyom) Kim <milo.kim@ti.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 version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/err.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/leds.h>
  19 #include <linux/mutex.h>
  20 #include <linux/mfd/lp8788.h>
  21 #include <linux/mfd/lp8788-isink.h>
  22
  23 #define MAX_BRIGHTNESS                  LP8788_ISINK_MAX_PWM
  24 #define DEFAULT_LED_NAME                "keyboard-backlight"
  25
  26 struct lp8788_led {
  27         struct lp8788 *lp;
  28         struct mutex lock;
  29         struct work_struct work;
  30         struct led_classdev led_dev;
  31         enum lp8788_isink_number isink_num;
  32         enum led_brightness brightness;
  33         int on;
  34 };
  35
  36 struct lp8788_led_config {
  37         enum lp8788_isink_scale scale;
  38         enum lp8788_isink_number num;
  39         int iout;
  40 };
  41
  42 static struct lp8788_led_config default_led_config = {
  43         .scale = LP8788_ISINK_SCALE_100mA,
  44         .num   = LP8788_ISINK_3,
  45         .iout  = 0,
  46 };
  47
  48 static int lp8788_led_init_device(struct lp8788_led *led,
  49                                 struct lp8788_led_platform_data *pdata)
  50 {
  51         struct lp8788_led_config *cfg = &default_led_config;
  52         u8 addr, mask, val;
  53         int ret;
  54
  55         if (pdata) {
  56                 cfg->scale = pdata->scale;
  57                 cfg->num = pdata->num;
  58                 cfg->iout = pdata->iout_code;
  59         }
  60
  61         led->isink_num = cfg->num;
  62
  63         /* scale configuration */
  64         addr = LP8788_ISINK_CTRL;
  65         mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  66         val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  67         ret = lp8788_update_bits(led->lp, addr, mask, val);
  68         if (ret)
  69                 return ret;
  70
  71         /* current configuration */
  72         addr = lp8788_iout_addr[cfg->num];
  73         mask = lp8788_iout_mask[cfg->num];
  74         val = cfg->iout;
  75
  76         return lp8788_update_bits(led->lp, addr, mask, val);
  77 }
  78
  79 static void lp8788_led_enable(struct lp8788_led *led,
  80                         enum lp8788_isink_number num, int on)
  81 {
  82         u8 mask = 1 << num;
  83         u8 val = on << num;
  84
  85         if (lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val))
  86                 return;
  87
  88         led->on = on;
  89 }
  90
  91 static void lp8788_led_work(struct work_struct *work)
  92 {
  93         struct lp8788_led *led = container_of(work, struct lp8788_led, work);
  94         enum lp8788_isink_number num = led->isink_num;
  95         int enable;
  96         u8 val = led->brightness;
  97
  98         mutex_lock(&led->lock);
  99
 100         switch (num) {
 101         case LP8788_ISINK_1:
 102         case LP8788_ISINK_2:
 103         case LP8788_ISINK_3:
 104                 lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
 105                 break;
 106         default:
 107                 mutex_unlock(&led->lock);
 108                 return;
 109         }
 110
 111         enable = (val > 0) ? 1 : 0;
 112         if (enable != led->on)
 113                 lp8788_led_enable(led, num, enable);
 114
 115         mutex_unlock(&led->lock);
 116 }
 117
 118 static void lp8788_brightness_set(struct led_classdev *led_cdev,
 119                                 enum led_brightness brt_val)
 120 {
 121         struct lp8788_led *led =
 122                         container_of(led_cdev, struct lp8788_led, led_dev);
 123
 124         led->brightness = brt_val;
 125         schedule_work(&led->work);
 126 }
 127
 128 static int lp8788_led_probe(struct platform_device *pdev)
 129 {
 130         struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
 131         struct lp8788_led_platform_data *led_pdata;
 132         struct lp8788_led *led;
 133         struct device *dev = &pdev->dev;
 134         int ret;
 135
 136         led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
 137         if (!led)
 138                 return -ENOMEM;
 139
 140         led->lp = lp;
 141         led->led_dev.max_brightness = MAX_BRIGHTNESS;
 142         led->led_dev.brightness_set = lp8788_brightness_set;
 143
 144         led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
 145
 146         if (!led_pdata || !led_pdata->name)
 147                 led->led_dev.name = DEFAULT_LED_NAME;
 148         else
 149                 led->led_dev.name = led_pdata->name;
 150
 151         mutex_init(&led->lock);
 152         INIT_WORK(&led->work, lp8788_led_work);
 153
 154         platform_set_drvdata(pdev, led);
 155
 156         ret = lp8788_led_init_device(led, led_pdata);
 157         if (ret) {
 158                 dev_err(dev, "led init device err: %d\n", ret);
 159                 return ret;
 160         }
 161
 162         ret = led_classdev_register(dev, &led->led_dev);
 163         if (ret) {
 164                 dev_err(dev, "led register err: %d\n", ret);
 165                 return ret;
 166         }
 167
 168         return 0;
 169 }
 170
 171 static int lp8788_led_remove(struct platform_device *pdev)
 172 {
 173         struct lp8788_led *led = platform_get_drvdata(pdev);
 174
 175         led_classdev_unregister(&led->led_dev);
 176         flush_work(&led->work);
 177
 178         return 0;
 179 }
 180
 181 static struct platform_driver lp8788_led_driver = {
 182         .probe = lp8788_led_probe,
 183         .remove = lp8788_led_remove,
 184         .driver = {
 185                 .name = LP8788_DEV_KEYLED,
 186         },
 187 };
 188 module_platform_driver(lp8788_led_driver);
 189
 190 MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
 191 MODULE_AUTHOR("Milo Kim");
 192 MODULE_LICENSE("GPL");
 193 MODULE_ALIAS("platform:lp8788-keyled");