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 
35 struct max77650_led {
36 	struct led_classdev cdev;
37 	struct regmap *map;
38 	unsigned int regA;
39 	unsigned int regB;
40 };
41 
max77650_to_led(struct led_classdev * cdev)42 static struct max77650_led *max77650_to_led(struct led_classdev *cdev)
43 {
44 	return container_of(cdev, struct max77650_led, cdev);
45 }
46 
max77650_led_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)47 static 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 
max77650_led_probe(struct platform_device * pdev)63 static 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);
125 err_node_put:
126 	fwnode_handle_put(child);
127 	return rv;
128 }
129 
130 static const struct of_device_id max77650_led_of_match[] = {
131 	{ .compatible = "maxim,max77650-led" },
132 	{ }
133 };
134 MODULE_DEVICE_TABLE(of, max77650_led_of_match);
135 
136 static 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 };
143 module_platform_driver(max77650_led_driver);
144 
145 MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
146 MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
147 MODULE_LICENSE("GPL v2");
148 MODULE_ALIAS("platform:max77650-led");
149