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 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", ®);
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
124 static const struct of_device_id max77650_led_of_match[] = {
125 { .compatible = "maxim,max77650-led" },
126 { }
127 };
128 MODULE_DEVICE_TABLE(of, max77650_led_of_match);
129
130 static 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 };
137 module_platform_driver(max77650_led_driver);
138
139 MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
140 MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
141 MODULE_LICENSE("GPL v2");
142 MODULE_ALIAS("platform:max77650-led");
143