linux/drivers/leds/leds-lp8788.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * TI LP8788 MFD - keyled driver
   4 *
   5 * Copyright 2012 Texas Instruments
   6 *
   7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/slab.h>
  12#include <linux/err.h>
  13#include <linux/platform_device.h>
  14#include <linux/leds.h>
  15#include <linux/mutex.h>
  16#include <linux/mfd/lp8788.h>
  17#include <linux/mfd/lp8788-isink.h>
  18
  19#define MAX_BRIGHTNESS                  LP8788_ISINK_MAX_PWM
  20#define DEFAULT_LED_NAME                "keyboard-backlight"
  21
  22struct lp8788_led {
  23        struct lp8788 *lp;
  24        struct mutex lock;
  25        struct led_classdev led_dev;
  26        enum lp8788_isink_number isink_num;
  27        int on;
  28};
  29
  30struct lp8788_led_config {
  31        enum lp8788_isink_scale scale;
  32        enum lp8788_isink_number num;
  33        int iout;
  34};
  35
  36static struct lp8788_led_config default_led_config = {
  37        .scale = LP8788_ISINK_SCALE_100mA,
  38        .num   = LP8788_ISINK_3,
  39        .iout  = 0,
  40};
  41
  42static int lp8788_led_init_device(struct lp8788_led *led,
  43                                struct lp8788_led_platform_data *pdata)
  44{
  45        struct lp8788_led_config *cfg = &default_led_config;
  46        u8 addr, mask, val;
  47        int ret;
  48
  49        if (pdata) {
  50                cfg->scale = pdata->scale;
  51                cfg->num = pdata->num;
  52                cfg->iout = pdata->iout_code;
  53        }
  54
  55        led->isink_num = cfg->num;
  56
  57        /* scale configuration */
  58        addr = LP8788_ISINK_CTRL;
  59        mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  60        val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  61        ret = lp8788_update_bits(led->lp, addr, mask, val);
  62        if (ret)
  63                return ret;
  64
  65        /* current configuration */
  66        addr = lp8788_iout_addr[cfg->num];
  67        mask = lp8788_iout_mask[cfg->num];
  68        val = cfg->iout;
  69
  70        return lp8788_update_bits(led->lp, addr, mask, val);
  71}
  72
  73static int lp8788_led_enable(struct lp8788_led *led,
  74                        enum lp8788_isink_number num, int on)
  75{
  76        int ret;
  77
  78        u8 mask = 1 << num;
  79        u8 val = on << num;
  80
  81        ret = lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val);
  82        if (ret == 0)
  83                led->on = on;
  84
  85        return ret;
  86}
  87
  88static int lp8788_brightness_set(struct led_classdev *led_cdev,
  89                                enum led_brightness val)
  90{
  91        struct lp8788_led *led =
  92                        container_of(led_cdev, struct lp8788_led, led_dev);
  93
  94        enum lp8788_isink_number num = led->isink_num;
  95        int enable, ret;
  96
  97        mutex_lock(&led->lock);
  98
  99        switch (num) {
 100        case LP8788_ISINK_1:
 101        case LP8788_ISINK_2:
 102        case LP8788_ISINK_3:
 103                ret = lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
 104                if (ret < 0)
 105                        goto unlock;
 106                break;
 107        default:
 108                mutex_unlock(&led->lock);
 109                return -EINVAL;
 110        }
 111
 112        enable = (val > 0) ? 1 : 0;
 113        if (enable != led->on)
 114                ret = lp8788_led_enable(led, num, enable);
 115unlock:
 116        mutex_unlock(&led->lock);
 117        return ret;
 118}
 119
 120static int lp8788_led_probe(struct platform_device *pdev)
 121{
 122        struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
 123        struct lp8788_led_platform_data *led_pdata;
 124        struct lp8788_led *led;
 125        struct device *dev = &pdev->dev;
 126        int ret;
 127
 128        led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
 129        if (!led)
 130                return -ENOMEM;
 131
 132        led->lp = lp;
 133        led->led_dev.max_brightness = MAX_BRIGHTNESS;
 134        led->led_dev.brightness_set_blocking = lp8788_brightness_set;
 135
 136        led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
 137
 138        if (!led_pdata || !led_pdata->name)
 139                led->led_dev.name = DEFAULT_LED_NAME;
 140        else
 141                led->led_dev.name = led_pdata->name;
 142
 143        mutex_init(&led->lock);
 144
 145        ret = lp8788_led_init_device(led, led_pdata);
 146        if (ret) {
 147                dev_err(dev, "led init device err: %d\n", ret);
 148                return ret;
 149        }
 150
 151        ret = devm_led_classdev_register(dev, &led->led_dev);
 152        if (ret) {
 153                dev_err(dev, "led register err: %d\n", ret);
 154                return ret;
 155        }
 156
 157        return 0;
 158}
 159
 160static struct platform_driver lp8788_led_driver = {
 161        .probe = lp8788_led_probe,
 162        .driver = {
 163                .name = LP8788_DEV_KEYLED,
 164        },
 165};
 166module_platform_driver(lp8788_led_driver);
 167
 168MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
 169MODULE_AUTHOR("Milo Kim");
 170MODULE_LICENSE("GPL");
 171MODULE_ALIAS("platform:lp8788-keyled");
 172