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 led_classdev led_dev;
  30         enum lp8788_isink_number isink_num;
  31         int on;
  32 };
  33
  34 struct lp8788_led_config {
  35         enum lp8788_isink_scale scale;
  36         enum lp8788_isink_number num;
  37         int iout;
  38 };
  39
  40 static struct lp8788_led_config default_led_config = {
  41         .scale = LP8788_ISINK_SCALE_100mA,
  42         .num   = LP8788_ISINK_3,
  43         .iout  = 0,
  44 };
  45
  46 static int lp8788_led_init_device(struct lp8788_led *led,
  47                                 struct lp8788_led_platform_data *pdata)
  48 {
  49         struct lp8788_led_config *cfg = &default_led_config;
  50         u8 addr, mask, val;
  51         int ret;
  52
  53         if (pdata) {
  54                 cfg->scale = pdata->scale;
  55                 cfg->num = pdata->num;
  56                 cfg->iout = pdata->iout_code;
  57         }
  58
  59         led->isink_num = cfg->num;
  60
  61         /* scale configuration */
  62         addr = LP8788_ISINK_CTRL;
  63         mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  64         val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  65         ret = lp8788_update_bits(led->lp, addr, mask, val);
  66         if (ret)
  67                 return ret;
  68
  69         /* current configuration */
  70         addr = lp8788_iout_addr[cfg->num];
  71         mask = lp8788_iout_mask[cfg->num];
  72         val = cfg->iout;
  73
  74         return lp8788_update_bits(led->lp, addr, mask, val);
  75 }
  76
  77 static int lp8788_led_enable(struct lp8788_led *led,
  78                         enum lp8788_isink_number num, int on)
  79 {
  80         int ret;
  81
  82         u8 mask = 1 << num;
  83         u8 val = on << num;
  84
  85         ret = lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val);
  86         if (ret == 0)
  87                 led->on = on;
  88
  89         return ret;
  90 }
  91
  92 static int lp8788_brightness_set(struct led_classdev *led_cdev,
  93                                 enum led_brightness val)
  94 {
  95         struct lp8788_led *led =
  96                         container_of(led_cdev, struct lp8788_led, led_dev);
  97
  98         enum lp8788_isink_number num = led->isink_num;
  99         int enable, ret;
 100
 101         mutex_lock(&led->lock);
 102
 103         switch (num) {
 104         case LP8788_ISINK_1:
 105         case LP8788_ISINK_2:
 106         case LP8788_ISINK_3:
 107                 ret = lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
 108                 if (ret < 0)
 109                         goto unlock;
 110                 break;
 111         default:
 112                 mutex_unlock(&led->lock);
 113                 return -EINVAL;
 114         }
 115
 116         enable = (val > 0) ? 1 : 0;
 117         if (enable != led->on)
 118                 ret = lp8788_led_enable(led, num, enable);
 119 unlock:
 120         mutex_unlock(&led->lock);
 121         return ret;
 122 }
 123
 124 static int lp8788_led_probe(struct platform_device *pdev)
 125 {
 126         struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
 127         struct lp8788_led_platform_data *led_pdata;
 128         struct lp8788_led *led;
 129         struct device *dev = &pdev->dev;
 130         int ret;
 131
 132         led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
 133         if (!led)
 134                 return -ENOMEM;
 135
 136         led->lp = lp;
 137         led->led_dev.max_brightness = MAX_BRIGHTNESS;
 138         led->led_dev.brightness_set_blocking = lp8788_brightness_set;
 139
 140         led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
 141
 142         if (!led_pdata || !led_pdata->name)
 143                 led->led_dev.name = DEFAULT_LED_NAME;
 144         else
 145                 led->led_dev.name = led_pdata->name;
 146
 147         mutex_init(&led->lock);
 148
 149         ret = lp8788_led_init_device(led, led_pdata);
 150         if (ret) {
 151                 dev_err(dev, "led init device err: %d\n", ret);
 152                 return ret;
 153         }
 154
 155         ret = devm_led_classdev_register(dev, &led->led_dev);
 156         if (ret) {
 157                 dev_err(dev, "led register err: %d\n", ret);
 158                 return ret;
 159         }
 160
 161         return 0;
 162 }
 163
 164 static struct platform_driver lp8788_led_driver = {
 165         .probe = lp8788_led_probe,
 166         .driver = {
 167                 .name = LP8788_DEV_KEYLED,
 168         },
 169 };
 170 module_platform_driver(lp8788_led_driver);
 171
 172 MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
 173 MODULE_AUTHOR("Milo Kim");
 174 MODULE_LICENSE("GPL");
 175 MODULE_ALIAS("platform:lp8788-keyled");