tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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 device_node *of_node, *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 of_node = dev->of_node;
75
76 if (!of_node)
77 return -ENODEV;
78
79 leds = devm_kcalloc(dev, sizeof(*leds),
80 MAX77650_LED_NUM_LEDS, GFP_KERNEL);
81 if (!leds)
82 return -ENOMEM;
83
84 map = dev_get_regmap(dev->parent, NULL);
85 if (!map)
86 return -ENODEV;
87
88 num_leds = of_get_child_count(of_node);
89 if (!num_leds || num_leds > MAX77650_LED_NUM_LEDS)
90 return -ENODEV;
91
92 for_each_child_of_node(of_node, child) {
93 rv = of_property_read_u32(child, "reg", ®);
94 if (rv || reg >= MAX77650_LED_NUM_LEDS)
95 return -EINVAL;
96
97 led = &leds[reg];
98 led->map = map;
99 led->regA = MAX77650_LED_A_BASE + reg;
100 led->regB = MAX77650_LED_B_BASE + reg;
101 led->cdev.brightness_set_blocking = max77650_led_brightness_set;
102 led->cdev.max_brightness = MAX77650_LED_MAX_BRIGHTNESS;
103
104 label = of_get_property(child, "label", NULL);
105 if (!label) {
106 led->cdev.name = "max77650::";
107 } else {
108 led->cdev.name = devm_kasprintf(dev, GFP_KERNEL,
109 "max77650:%s", label);
110 if (!led->cdev.name)
111 return -ENOMEM;
112 }
113
114 of_property_read_string(child, "linux,default-trigger",
115 &led->cdev.default_trigger);
116
117 rv = devm_of_led_classdev_register(dev, child, &led->cdev);
118 if (rv)
119 return rv;
120
121 rv = regmap_write(map, led->regA, MAX77650_LED_A_DEFAULT);
122 if (rv)
123 return rv;
124
125 rv = regmap_write(map, led->regB, MAX77650_LED_B_DEFAULT);
126 if (rv)
127 return rv;
128 }
129
130 return regmap_write(map,
131 MAX77650_REG_CNFG_LED_TOP,
132 MAX77650_LED_TOP_DEFAULT);
133}
134
135static struct platform_driver max77650_led_driver = {
136 .driver = {
137 .name = "max77650-led",
138 },
139 .probe = max77650_led_probe,
140};
141module_platform_driver(max77650_led_driver);
142
143MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
144MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
145MODULE_LICENSE("GPL v2");