LXR linux/drivers/leds/leds-max77650.c

   1// SPDX-License-Identifier: GPL-2.0
   2//
   3// Copyright (C) 2018 BayLibre SAS
   4// Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
   5//
   6// LED driver for MAXIM 77650/77651 charger/power-supply.
   7
   8#include <linux/i2c.h>
   9#include <linux/leds.h>
  10#include <linux/mfd/max77650.h>
  11#include <linux/module.h>
  12#include <linux/platform_device.h>
  13#include <linux/regmap.h>
  14
  15#define MAX77650_LED_NUM_LEDS           3
  16
  17#define MAX77650_LED_A_BASE             0x40
  18#define MAX77650_LED_B_BASE             0x43
  19
  20#define MAX77650_LED_BR_MASK            GENMASK(4, 0)
  21#define MAX77650_LED_EN_MASK            GENMASK(7, 6)
  22
  23#define MAX77650_LED_MAX_BRIGHTNESS     MAX77650_LED_BR_MASK
  24
  25/* Enable EN_LED_MSTR. */
  26#define MAX77650_LED_TOP_DEFAULT        BIT(0)
  27
  28#define MAX77650_LED_ENABLE             GENMASK(7, 6)
  29#define MAX77650_LED_DISABLE            0x00
  30
  31#define MAX77650_LED_A_DEFAULT          MAX77650_LED_DISABLE
  32/* 100% on duty */
  33#define MAX77650_LED_B_DEFAULT          GENMASK(3, 0)
  34
  35struct max77650_led {
  36        struct led_classdev cdev;
  37        struct regmap *map;
  38        unsigned int regA;
  39        unsigned int regB;
  40};
  41
  42static struct max77650_led *max77650_to_led(struct led_classdev *cdev)
  43{
  44        return container_of(cdev, struct max77650_led, cdev);
  45}
  46
  47static int max77650_led_brightness_set(struct led_classdev *cdev,
  48                                       enum led_brightness brightness)
  49{
  50        struct max77650_led *led = max77650_to_led(cdev);
  51        int val, mask;
  52
  53        mask = MAX77650_LED_BR_MASK | MAX77650_LED_EN_MASK;
  54
  55        if (brightness == LED_OFF)
  56                val = MAX77650_LED_DISABLE;
  57        else
  58                val = MAX77650_LED_ENABLE | brightness;
  59
  60        return regmap_update_bits(led->map, led->regA, mask, val);
  61}
  62
  63static int max77650_led_probe(struct platform_device *pdev)
  64{
  65        struct fwnode_handle *child;
  66        struct max77650_led *leds, *led;
  67        struct device *dev;
  68        struct regmap *map;
  69        int rv, num_leds;
  70        u32 reg;
  71
  72        dev = &pdev->dev;
  73
  74        leds = devm_kcalloc(dev, sizeof(*leds),
  75                            MAX77650_LED_NUM_LEDS, GFP_KERNEL);
  76        if (!leds)
  77                return -ENOMEM;
  78
  79        map = dev_get_regmap(dev->parent, NULL);
  80        if (!map)
  81                return -ENODEV;
  82
  83        num_leds = device_get_child_node_count(dev);
  84        if (!num_leds || num_leds > MAX77650_LED_NUM_LEDS)
  85                return -ENODEV;
  86
  87        device_for_each_child_node(dev, child) {
  88                struct led_init_data init_data = {};
  89
  90                rv = fwnode_property_read_u32(child, "reg", &reg);
  91                if (rv || reg >= MAX77650_LED_NUM_LEDS) {
  92                        rv = -EINVAL;
  93                        goto err_node_put;
  94                }
  95
  96                led = &leds[reg];
  97                led->map = map;
  98                led->regA = MAX77650_LED_A_BASE + reg;
  99                led->regB = MAX77650_LED_B_BASE + reg;
 100                led->cdev.brightness_set_blocking = max77650_led_brightness_set;
 101                led->cdev.max_brightness = MAX77650_LED_MAX_BRIGHTNESS;
 102
 103                init_data.fwnode = child;
 104                init_data.devicename = "max77650";
 105                /* for backwards compatibility if `label` is not present */
 106                init_data.default_label = ":";
 107
 108                rv = devm_led_classdev_register_ext(dev, &led->cdev,
 109                                                    &init_data);
 110                if (rv)
 111                        goto err_node_put;
 112
 113                rv = regmap_write(map, led->regA, MAX77650_LED_A_DEFAULT);
 114                if (rv)
 115                        goto err_node_put;
 116
 117                rv = regmap_write(map, led->regB, MAX77650_LED_B_DEFAULT);
 118                if (rv)
 119                        goto err_node_put;
 120        }
 121
 122        return regmap_write(map,
 123                            MAX77650_REG_CNFG_LED_TOP,
 124                            MAX77650_LED_TOP_DEFAULT);
 125err_node_put:
 126        fwnode_handle_put(child);
 127        return rv;
 128}
 129
 130static const struct of_device_id max77650_led_of_match[] = {
 131        { .compatible = "maxim,max77650-led" },
 132        { }
 133};
 134MODULE_DEVICE_TABLE(of, max77650_led_of_match);
 135
 136static struct platform_driver max77650_led_driver = {
 137        .driver = {
 138                .name = "max77650-led",
 139                .of_match_table = max77650_led_of_match,
 140        },
 141        .probe = max77650_led_probe,
 142};
 143module_platform_driver(max77650_led_driver);
 144
 145MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
 146MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
 147MODULE_LICENSE("GPL v2");
 148MODULE_ALIAS("platform:max77650-led");
 149