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