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 max77650_led *leds, *led;
 66	struct device *dev;
 67	struct regmap *map;
 68	int rv, num_leds;
 69	u32 reg;
 70
 71	dev = &pdev->dev;
 72
 73	leds = devm_kcalloc(dev, sizeof(*leds),
 74			    MAX77650_LED_NUM_LEDS, GFP_KERNEL);
 75	if (!leds)
 76		return -ENOMEM;
 77
 78	map = dev_get_regmap(dev->parent, NULL);
 79	if (!map)
 80		return -ENODEV;
 81
 82	num_leds = device_get_child_node_count(dev);
 83	if (!num_leds || num_leds > MAX77650_LED_NUM_LEDS)
 84		return -ENODEV;
 85
 86	device_for_each_child_node_scoped(dev, child) {
 87		struct led_init_data init_data = {};
 88
 89		rv = fwnode_property_read_u32(child, "reg", &reg);
 90		if (rv || reg >= MAX77650_LED_NUM_LEDS)
 91			return -EINVAL;
 92
 93		led = &leds[reg];
 94		led->map = map;
 95		led->regA = MAX77650_LED_A_BASE + reg;
 96		led->regB = MAX77650_LED_B_BASE + reg;
 97		led->cdev.brightness_set_blocking = max77650_led_brightness_set;
 98		led->cdev.max_brightness = MAX77650_LED_MAX_BRIGHTNESS;
 99
100		init_data.fwnode = child;
101		init_data.devicename = "max77650";
102		/* for backwards compatibility if `label` is not present */
103		init_data.default_label = ":";
104
105		rv = devm_led_classdev_register_ext(dev, &led->cdev,
106						    &init_data);
107		if (rv)
108			return rv;
109
110		rv = regmap_write(map, led->regA, MAX77650_LED_A_DEFAULT);
111		if (rv)
112			return rv;
113
114		rv = regmap_write(map, led->regB, MAX77650_LED_B_DEFAULT);
115		if (rv)
116			return rv;
117	}
118
119	return regmap_write(map,
120			    MAX77650_REG_CNFG_LED_TOP,
121			    MAX77650_LED_TOP_DEFAULT);
122}
123
124static const struct of_device_id max77650_led_of_match[] = {
125	{ .compatible = "maxim,max77650-led" },
126	{ }
127};
128MODULE_DEVICE_TABLE(of, max77650_led_of_match);
129
130static struct platform_driver max77650_led_driver = {
131	.driver = {
132		.name = "max77650-led",
133		.of_match_table = max77650_led_of_match,
134	},
135	.probe = max77650_led_probe,
136};
137module_platform_driver(max77650_led_driver);
138
139MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
140MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
141MODULE_LICENSE("GPL v2");
142MODULE_ALIAS("platform:max77650-led");