1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // TI LM36274 LED chip family driver |
3 | // Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/ |
4 | |
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/mod_devicetable.h> |
11 | #include <linux/module.h> |
12 | #include <linux/platform_device.h> |
13 | #include <linux/property.h> |
14 | |
15 | #include <linux/mfd/ti-lmu.h> |
16 | #include <linux/mfd/ti-lmu-register.h> |
17 | |
18 | #include <uapi/linux/uleds.h> |
19 | |
20 | #define LM36274_MAX_STRINGS 4 |
21 | #define LM36274_BL_EN BIT(4) |
22 | |
23 | /** |
24 | * struct lm36274 |
25 | * @pdev: platform device |
26 | * @led_dev: led class device |
27 | * @lmu_data: Register and setting values for common code |
28 | * @regmap: Devices register map |
29 | * @dev: Pointer to the devices device struct |
30 | * @led_sources: The LED strings supported in this array |
31 | * @num_leds: Number of LED strings are supported in this array |
32 | */ |
33 | struct lm36274 { |
34 | struct platform_device *pdev; |
35 | struct led_classdev led_dev; |
36 | struct ti_lmu_bank lmu_data; |
37 | struct regmap *regmap; |
38 | struct device *dev; |
39 | |
40 | u32 led_sources[LM36274_MAX_STRINGS]; |
41 | int num_leds; |
42 | }; |
43 | |
44 | static int lm36274_brightness_set(struct led_classdev *led_cdev, |
45 | enum led_brightness brt_val) |
46 | { |
47 | struct lm36274 *chip = container_of(led_cdev, struct lm36274, led_dev); |
48 | |
49 | return ti_lmu_common_set_brightness(lmu_bank: &chip->lmu_data, brightness: brt_val); |
50 | } |
51 | |
52 | static int lm36274_init(struct lm36274 *chip) |
53 | { |
54 | int enable_val = 0; |
55 | int i; |
56 | |
57 | for (i = 0; i < chip->num_leds; i++) |
58 | enable_val |= (1 << chip->led_sources[i]); |
59 | |
60 | if (!enable_val) { |
61 | dev_err(chip->dev, "No LEDs were enabled\n" ); |
62 | return -EINVAL; |
63 | } |
64 | |
65 | enable_val |= LM36274_BL_EN; |
66 | |
67 | return regmap_write(map: chip->regmap, LM36274_REG_BL_EN, val: enable_val); |
68 | } |
69 | |
70 | static int lm36274_parse_dt(struct lm36274 *chip, |
71 | struct led_init_data *init_data) |
72 | { |
73 | struct device *dev = chip->dev; |
74 | struct fwnode_handle *child; |
75 | int ret; |
76 | |
77 | /* There should only be 1 node */ |
78 | if (device_get_child_node_count(dev) != 1) |
79 | return -EINVAL; |
80 | |
81 | child = device_get_next_child_node(dev, NULL); |
82 | |
83 | init_data->fwnode = child; |
84 | init_data->devicename = chip->pdev->name; |
85 | /* for backwards compatibility when `label` property is not present */ |
86 | init_data->default_label = ":" ; |
87 | |
88 | chip->num_leds = fwnode_property_count_u32(fwnode: child, propname: "led-sources" ); |
89 | if (chip->num_leds <= 0) { |
90 | ret = -ENODEV; |
91 | goto err; |
92 | } |
93 | |
94 | ret = fwnode_property_read_u32_array(fwnode: child, propname: "led-sources" , |
95 | val: chip->led_sources, nval: chip->num_leds); |
96 | if (ret) { |
97 | dev_err(dev, "led-sources property missing\n" ); |
98 | goto err; |
99 | } |
100 | |
101 | return 0; |
102 | err: |
103 | fwnode_handle_put(fwnode: child); |
104 | return ret; |
105 | } |
106 | |
107 | static int lm36274_probe(struct platform_device *pdev) |
108 | { |
109 | struct ti_lmu *lmu = dev_get_drvdata(dev: pdev->dev.parent); |
110 | struct led_init_data init_data = {}; |
111 | struct lm36274 *chip; |
112 | int ret; |
113 | |
114 | chip = devm_kzalloc(dev: &pdev->dev, size: sizeof(*chip), GFP_KERNEL); |
115 | if (!chip) |
116 | return -ENOMEM; |
117 | |
118 | chip->pdev = pdev; |
119 | chip->dev = &pdev->dev; |
120 | chip->regmap = lmu->regmap; |
121 | platform_set_drvdata(pdev, data: chip); |
122 | |
123 | ret = lm36274_parse_dt(chip, init_data: &init_data); |
124 | if (ret) { |
125 | dev_err(chip->dev, "Failed to parse DT node\n" ); |
126 | return ret; |
127 | } |
128 | |
129 | ret = lm36274_init(chip); |
130 | if (ret) { |
131 | fwnode_handle_put(fwnode: init_data.fwnode); |
132 | dev_err(chip->dev, "Failed to init the device\n" ); |
133 | return ret; |
134 | } |
135 | |
136 | chip->lmu_data.regmap = chip->regmap; |
137 | chip->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT; |
138 | chip->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB; |
139 | chip->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB; |
140 | |
141 | chip->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT; |
142 | chip->led_dev.brightness_set_blocking = lm36274_brightness_set; |
143 | |
144 | ret = devm_led_classdev_register_ext(parent: chip->dev, led_cdev: &chip->led_dev, |
145 | init_data: &init_data); |
146 | if (ret) |
147 | dev_err(chip->dev, "Failed to register LED for node %pfw\n" , |
148 | init_data.fwnode); |
149 | |
150 | fwnode_handle_put(fwnode: init_data.fwnode); |
151 | |
152 | return ret; |
153 | } |
154 | |
155 | static const struct of_device_id of_lm36274_leds_match[] = { |
156 | { .compatible = "ti,lm36274-backlight" , }, |
157 | {}, |
158 | }; |
159 | MODULE_DEVICE_TABLE(of, of_lm36274_leds_match); |
160 | |
161 | static struct platform_driver lm36274_driver = { |
162 | .probe = lm36274_probe, |
163 | .driver = { |
164 | .name = "lm36274-leds" , |
165 | .of_match_table = of_lm36274_leds_match, |
166 | }, |
167 | }; |
168 | module_platform_driver(lm36274_driver) |
169 | |
170 | MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver" ); |
171 | MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>" ); |
172 | MODULE_LICENSE("GPL v2" ); |
173 | |