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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
4f811ef0 HZ |
2 | /* |
3 | * Backlight driver for Maxim MAX8925 | |
4 | * | |
5 | * Copyright (C) 2009 Marvell International Ltd. | |
6 | * Haojian Zhuang <haojian.zhuang@marvell.com> | |
4f811ef0 HZ |
7 | */ |
8 | ||
9 | #include <linux/init.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/fb.h> | |
13 | #include <linux/i2c.h> | |
14 | #include <linux/backlight.h> | |
15 | #include <linux/mfd/max8925.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
355b200b | 17 | #include <linux/module.h> |
4f811ef0 HZ |
18 | |
19 | #define MAX_BRIGHTNESS (0xff) | |
20 | #define MIN_BRIGHTNESS (0) | |
21 | ||
22 | #define LWX_FREQ(x) (((x - 601) / 100) & 0x7) | |
23 | ||
24 | struct max8925_backlight_data { | |
25 | struct max8925_chip *chip; | |
26 | ||
63b501e2 HZ |
27 | int current_brightness; |
28 | int reg_mode_cntl; | |
29 | int reg_cntl; | |
4f811ef0 HZ |
30 | }; |
31 | ||
32 | static int max8925_backlight_set(struct backlight_device *bl, int brightness) | |
33 | { | |
34 | struct max8925_backlight_data *data = bl_get_data(bl); | |
35 | struct max8925_chip *chip = data->chip; | |
36 | unsigned char value; | |
37 | int ret; | |
38 | ||
39 | if (brightness > MAX_BRIGHTNESS) | |
40 | value = MAX_BRIGHTNESS; | |
41 | else | |
42 | value = brightness; | |
43 | ||
63b501e2 | 44 | ret = max8925_reg_write(chip->i2c, data->reg_cntl, value); |
4f811ef0 HZ |
45 | if (ret < 0) |
46 | goto out; | |
47 | ||
48 | if (!data->current_brightness && brightness) | |
49 | /* enable WLED output */ | |
63b501e2 | 50 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 1); |
4f811ef0 HZ |
51 | else if (!brightness) |
52 | /* disable WLED output */ | |
63b501e2 | 53 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 0); |
4f811ef0 HZ |
54 | if (ret < 0) |
55 | goto out; | |
56 | dev_dbg(chip->dev, "set brightness %d\n", value); | |
57 | data->current_brightness = value; | |
58 | return 0; | |
59 | out: | |
60 | dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n", | |
61 | value, ret); | |
62 | return ret; | |
63 | } | |
64 | ||
65 | static int max8925_backlight_update_status(struct backlight_device *bl) | |
66 | { | |
67 | int brightness = bl->props.brightness; | |
68 | ||
69 | if (bl->props.power != FB_BLANK_UNBLANK) | |
70 | brightness = 0; | |
71 | ||
72 | if (bl->props.fb_blank != FB_BLANK_UNBLANK) | |
73 | brightness = 0; | |
74 | ||
75 | if (bl->props.state & BL_CORE_SUSPENDED) | |
76 | brightness = 0; | |
77 | ||
78 | return max8925_backlight_set(bl, brightness); | |
79 | } | |
80 | ||
81 | static int max8925_backlight_get_brightness(struct backlight_device *bl) | |
82 | { | |
83 | struct max8925_backlight_data *data = bl_get_data(bl); | |
84 | struct max8925_chip *chip = data->chip; | |
85 | int ret; | |
86 | ||
63b501e2 | 87 | ret = max8925_reg_read(chip->i2c, data->reg_cntl); |
4f811ef0 HZ |
88 | if (ret < 0) |
89 | return -EINVAL; | |
90 | data->current_brightness = ret; | |
91 | dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); | |
92 | return ret; | |
93 | } | |
94 | ||
acc2472e | 95 | static const struct backlight_ops max8925_backlight_ops = { |
4f811ef0 HZ |
96 | .options = BL_CORE_SUSPENDRESUME, |
97 | .update_status = max8925_backlight_update_status, | |
98 | .get_brightness = max8925_backlight_get_brightness, | |
99 | }; | |
100 | ||
515c0967 | 101 | static void max8925_backlight_dt_init(struct platform_device *pdev) |
47ec340c QX |
102 | { |
103 | struct device_node *nproot = pdev->dev.parent->of_node, *np; | |
515c0967 OJ |
104 | struct max8925_backlight_pdata *pdata; |
105 | u32 val; | |
106 | ||
107 | if (!nproot || !IS_ENABLED(CONFIG_OF)) | |
108 | return; | |
109 | ||
110 | pdata = devm_kzalloc(&pdev->dev, | |
111 | sizeof(struct max8925_backlight_pdata), | |
112 | GFP_KERNEL); | |
113 | if (!pdata) | |
114 | return; | |
47ec340c | 115 | |
d1cc0ec3 | 116 | np = of_get_child_by_name(nproot, "backlight"); |
47ec340c QX |
117 | if (!np) { |
118 | dev_err(&pdev->dev, "failed to find backlight node\n"); | |
515c0967 | 119 | return; |
47ec340c QX |
120 | } |
121 | ||
515c0967 OJ |
122 | if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val)) |
123 | pdata->dual_string = val; | |
124 | ||
d1cc0ec3 JH |
125 | of_node_put(np); |
126 | ||
515c0967 | 127 | pdev->dev.platform_data = pdata; |
47ec340c | 128 | } |
47ec340c | 129 | |
1b9e450d | 130 | static int max8925_backlight_probe(struct platform_device *pdev) |
4f811ef0 HZ |
131 | { |
132 | struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); | |
515c0967 | 133 | struct max8925_backlight_pdata *pdata; |
4f811ef0 HZ |
134 | struct max8925_backlight_data *data; |
135 | struct backlight_device *bl; | |
a19a6ee6 | 136 | struct backlight_properties props; |
4f811ef0 | 137 | struct resource *res; |
4f811ef0 | 138 | unsigned char value; |
63b501e2 | 139 | int ret = 0; |
4f811ef0 | 140 | |
ce969228 JL |
141 | data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data), |
142 | GFP_KERNEL); | |
4f811ef0 HZ |
143 | if (data == NULL) |
144 | return -ENOMEM; | |
63b501e2 HZ |
145 | |
146 | res = platform_get_resource(pdev, IORESOURCE_REG, 0); | |
147 | if (!res) { | |
148 | dev_err(&pdev->dev, "No REG resource for mode control!\n"); | |
2c114cb4 | 149 | return -ENXIO; |
63b501e2 HZ |
150 | } |
151 | data->reg_mode_cntl = res->start; | |
152 | res = platform_get_resource(pdev, IORESOURCE_REG, 1); | |
153 | if (!res) { | |
154 | dev_err(&pdev->dev, "No REG resource for control!\n"); | |
2c114cb4 | 155 | return -ENXIO; |
63b501e2 HZ |
156 | } |
157 | data->reg_cntl = res->start; | |
158 | ||
4f811ef0 HZ |
159 | data->chip = chip; |
160 | data->current_brightness = 0; | |
161 | ||
a19a6ee6 | 162 | memset(&props, 0, sizeof(struct backlight_properties)); |
bb7ca747 | 163 | props.type = BACKLIGHT_RAW; |
a19a6ee6 | 164 | props.max_brightness = MAX_BRIGHTNESS; |
18d9dbce JH |
165 | bl = devm_backlight_device_register(&pdev->dev, "max8925-backlight", |
166 | &pdev->dev, data, | |
a19a6ee6 | 167 | &max8925_backlight_ops, &props); |
4f811ef0 HZ |
168 | if (IS_ERR(bl)) { |
169 | dev_err(&pdev->dev, "failed to register backlight\n"); | |
2c114cb4 | 170 | return PTR_ERR(bl); |
4f811ef0 | 171 | } |
4f811ef0 HZ |
172 | bl->props.brightness = MAX_BRIGHTNESS; |
173 | ||
174 | platform_set_drvdata(pdev, bl); | |
175 | ||
176 | value = 0; | |
515c0967 OJ |
177 | if (!pdev->dev.platform_data) |
178 | max8925_backlight_dt_init(pdev); | |
47ec340c | 179 | |
515c0967 | 180 | pdata = pdev->dev.platform_data; |
63b501e2 HZ |
181 | if (pdata) { |
182 | if (pdata->lxw_scl) | |
183 | value |= (1 << 7); | |
184 | if (pdata->lxw_freq) | |
185 | value |= (LWX_FREQ(pdata->lxw_freq) << 4); | |
186 | if (pdata->dual_string) | |
187 | value |= (1 << 1); | |
188 | } | |
189 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value); | |
4f811ef0 | 190 | if (ret < 0) |
18d9dbce | 191 | return ret; |
4f811ef0 HZ |
192 | backlight_update_status(bl); |
193 | return 0; | |
4f811ef0 HZ |
194 | } |
195 | ||
196 | static struct platform_driver max8925_backlight_driver = { | |
197 | .driver = { | |
198 | .name = "max8925-backlight", | |
4f811ef0 HZ |
199 | }, |
200 | .probe = max8925_backlight_probe, | |
4f811ef0 HZ |
201 | }; |
202 | ||
81178e02 | 203 | module_platform_driver(max8925_backlight_driver); |
4f811ef0 HZ |
204 | |
205 | MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925"); | |
206 | MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); | |
207 | MODULE_LICENSE("GPL"); | |
208 | MODULE_ALIAS("platform:max8925-backlight"); |