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5#include <linux/bitops.h>
6#include <linux/device.h>
7#include <linux/err.h>
8#include <linux/leds.h>
9#include <linux/leds-ti-lmu-common.h>
10#include <linux/module.h>
11#include <linux/of_device.h>
12#include <linux/platform_device.h>
13
14#include <linux/mfd/ti-lmu.h>
15#include <linux/mfd/ti-lmu-register.h>
16
17#include <uapi/linux/uleds.h>
18
19#define LM36274_MAX_STRINGS 4
20#define LM36274_BL_EN BIT(4)
21
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31
32struct lm36274 {
33 struct platform_device *pdev;
34 struct led_classdev led_dev;
35 struct ti_lmu_bank lmu_data;
36 struct regmap *regmap;
37 struct device *dev;
38
39 u32 led_sources[LM36274_MAX_STRINGS];
40 int num_leds;
41};
42
43static int lm36274_brightness_set(struct led_classdev *led_cdev,
44 enum led_brightness brt_val)
45{
46 struct lm36274 *led = container_of(led_cdev, struct lm36274, led_dev);
47
48 return ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
49}
50
51static int lm36274_init(struct lm36274 *lm36274_data)
52{
53 int enable_val = 0;
54 int i;
55
56 for (i = 0; i < lm36274_data->num_leds; i++)
57 enable_val |= (1 << lm36274_data->led_sources[i]);
58
59 if (!enable_val) {
60 dev_err(lm36274_data->dev, "No LEDs were enabled\n");
61 return -EINVAL;
62 }
63
64 enable_val |= LM36274_BL_EN;
65
66 return regmap_write(lm36274_data->regmap, LM36274_REG_BL_EN,
67 enable_val);
68}
69
70static int lm36274_parse_dt(struct lm36274 *lm36274_data)
71{
72 struct fwnode_handle *child = NULL;
73 char label[LED_MAX_NAME_SIZE];
74 struct device *dev = &lm36274_data->pdev->dev;
75 const char *name;
76 int child_cnt;
77 int ret = -EINVAL;
78
79
80 child_cnt = device_get_child_node_count(dev);
81 if (child_cnt != 1)
82 return -EINVAL;
83
84 device_for_each_child_node(dev, child) {
85 ret = fwnode_property_read_string(child, "label", &name);
86 if (ret)
87 snprintf(label, sizeof(label),
88 "%s::", lm36274_data->pdev->name);
89 else
90 snprintf(label, sizeof(label),
91 "%s:%s", lm36274_data->pdev->name, name);
92
93 lm36274_data->num_leds = fwnode_property_read_u32_array(child,
94 "led-sources",
95 NULL, 0);
96 if (lm36274_data->num_leds <= 0)
97 return -ENODEV;
98
99 ret = fwnode_property_read_u32_array(child, "led-sources",
100 lm36274_data->led_sources,
101 lm36274_data->num_leds);
102 if (ret) {
103 dev_err(dev, "led-sources property missing\n");
104 return ret;
105 }
106
107 fwnode_property_read_string(child, "linux,default-trigger",
108 &lm36274_data->led_dev.default_trigger);
109
110 }
111
112 lm36274_data->lmu_data.regmap = lm36274_data->regmap;
113 lm36274_data->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT;
114 lm36274_data->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB;
115 lm36274_data->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB;
116
117 lm36274_data->led_dev.name = label;
118 lm36274_data->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT;
119 lm36274_data->led_dev.brightness_set_blocking = lm36274_brightness_set;
120
121 return 0;
122}
123
124static int lm36274_probe(struct platform_device *pdev)
125{
126 struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent);
127 struct lm36274 *lm36274_data;
128 int ret;
129
130 lm36274_data = devm_kzalloc(&pdev->dev, sizeof(*lm36274_data),
131 GFP_KERNEL);
132 if (!lm36274_data)
133 return -ENOMEM;
134
135 lm36274_data->pdev = pdev;
136 lm36274_data->dev = lmu->dev;
137 lm36274_data->regmap = lmu->regmap;
138 dev_set_drvdata(&pdev->dev, lm36274_data);
139
140 ret = lm36274_parse_dt(lm36274_data);
141 if (ret) {
142 dev_err(lm36274_data->dev, "Failed to parse DT node\n");
143 return ret;
144 }
145
146 ret = lm36274_init(lm36274_data);
147 if (ret) {
148 dev_err(lm36274_data->dev, "Failed to init the device\n");
149 return ret;
150 }
151
152 return devm_led_classdev_register(lm36274_data->dev,
153 &lm36274_data->led_dev);
154}
155
156static const struct of_device_id of_lm36274_leds_match[] = {
157 { .compatible = "ti,lm36274-backlight", },
158 {},
159};
160MODULE_DEVICE_TABLE(of, of_lm36274_leds_match);
161
162static struct platform_driver lm36274_driver = {
163 .probe = lm36274_probe,
164 .driver = {
165 .name = "lm36274-leds",
166 },
167};
168module_platform_driver(lm36274_driver)
169
170MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver");
171MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
172MODULE_LICENSE("GPL v2");
173
