linux/drivers/leds/leds-lp8788.c
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   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
  26struct 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
  34struct lp8788_led_config {
  35        enum lp8788_isink_scale scale;
  36        enum lp8788_isink_number num;
  37        int iout;
  38};
  39
  40static struct lp8788_led_config default_led_config = {
  41        .scale = LP8788_ISINK_SCALE_100mA,
  42        .num   = LP8788_ISINK_3,
  43        .iout  = 0,
  44};
  45
  46static 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
  77static 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
  92static 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);
 119unlock:
 120        mutex_unlock(&led->lock);
 121        return ret;
 122}
 123
 124static 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
 164static struct platform_driver lp8788_led_driver = {
 165        .probe = lp8788_led_probe,
 166        .driver = {
 167                .name = LP8788_DEV_KEYLED,
 168        },
 169};
 170module_platform_driver(lp8788_led_driver);
 171
 172MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
 173MODULE_AUTHOR("Milo Kim");
 174MODULE_LICENSE("GPL");
 175MODULE_ALIAS("platform:lp8788-keyled");
 176