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 const char *label;
70 int rv, num_leds;
71 u32 reg;
72
73 dev = &pdev->dev;
74
75 leds = devm_kcalloc(dev, sizeof(*leds),
76 MAX77650_LED_NUM_LEDS, GFP_KERNEL);
77 if (!leds)
78 return -ENOMEM;
79
80 map = dev_get_regmap(dev->parent, NULL);
81 if (!map)
82 return -ENODEV;
83
84 num_leds = device_get_child_node_count(dev);
85 if (!num_leds || num_leds > MAX77650_LED_NUM_LEDS)
86 return -ENODEV;
87
88 device_for_each_child_node(dev, child) {
89 rv = fwnode_property_read_u32(child, "reg", ®);
90 if (rv || reg >= MAX77650_LED_NUM_LEDS) {
91 rv = -EINVAL;
92 goto err_node_put;
93 }
94
95 led = &leds[reg];
96 led->map = map;
97 led->regA = MAX77650_LED_A_BASE + reg;
98 led->regB = MAX77650_LED_B_BASE + reg;
99 led->cdev.brightness_set_blocking = max77650_led_brightness_set;
100 led->cdev.max_brightness = MAX77650_LED_MAX_BRIGHTNESS;
101
102 rv = fwnode_property_read_string(child, "label", &label);
103 if (rv) {
104 led->cdev.name = "max77650::";
105 } else {
106 led->cdev.name = devm_kasprintf(dev, GFP_KERNEL,
107 "max77650:%s", label);
108 if (!led->cdev.name) {
109 rv = -ENOMEM;
110 goto err_node_put;
111 }
112 }
113
114 fwnode_property_read_string(child, "linux,default-trigger",
115 &led->cdev.default_trigger);
116
117 rv = devm_led_classdev_register(dev, &led->cdev);
118 if (rv)
119 goto err_node_put;
120
121 rv = regmap_write(map, led->regA, MAX77650_LED_A_DEFAULT);
122 if (rv)
123 goto err_node_put;
124
125 rv = regmap_write(map, led->regB, MAX77650_LED_B_DEFAULT);
126 if (rv)
127 goto err_node_put;
128 }
129
130 return regmap_write(map,
131 MAX77650_REG_CNFG_LED_TOP,
132 MAX77650_LED_TOP_DEFAULT);
133 err_node_put:
134 fwnode_handle_put(child);
135 return rv;
136 }
137
138 static struct platform_driver max77650_led_driver = {
139 .driver = {
140 .name = "max77650-led",
141 },
142 .probe = max77650_led_probe,
143 };
144 module_platform_driver(max77650_led_driver);
145
146 MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
147 MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
148 MODULE_LICENSE("GPL v2");
149 MODULE_ALIAS("platform:max77650-led");
150