1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/drivers/video/backlight/aat2870_bl.c |
4 | * |
5 | * Copyright (c) 2011, NVIDIA Corporation. |
6 | * Author: Jin Park <jinyoungp@nvidia.com> |
7 | */ |
8 | |
9 | #include <linux/module.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/init.h> |
12 | #include <linux/platform_device.h> |
13 | #include <linux/mutex.h> |
14 | #include <linux/delay.h> |
15 | #include <linux/fb.h> |
16 | #include <linux/backlight.h> |
17 | #include <linux/mfd/aat2870.h> |
18 | |
19 | struct aat2870_bl_driver_data { |
20 | struct platform_device *pdev; |
21 | struct backlight_device *bd; |
22 | |
23 | int channels; |
24 | int max_current; |
25 | int brightness; /* current brightness */ |
26 | }; |
27 | |
28 | static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl, |
29 | int brightness) |
30 | { |
31 | struct backlight_device *bd = aat2870_bl->bd; |
32 | int val; |
33 | |
34 | val = brightness * (aat2870_bl->max_current - 1); |
35 | val /= bd->props.max_brightness; |
36 | |
37 | return val; |
38 | } |
39 | |
40 | static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl) |
41 | { |
42 | struct aat2870_data *aat2870 |
43 | = dev_get_drvdata(dev: aat2870_bl->pdev->dev.parent); |
44 | |
45 | return aat2870->write(aat2870, AAT2870_BL_CH_EN, |
46 | (u8)aat2870_bl->channels); |
47 | } |
48 | |
49 | static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl) |
50 | { |
51 | struct aat2870_data *aat2870 |
52 | = dev_get_drvdata(dev: aat2870_bl->pdev->dev.parent); |
53 | |
54 | return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0); |
55 | } |
56 | |
57 | static int aat2870_bl_update_status(struct backlight_device *bd) |
58 | { |
59 | struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bl_dev: bd); |
60 | struct aat2870_data *aat2870 = |
61 | dev_get_drvdata(dev: aat2870_bl->pdev->dev.parent); |
62 | int brightness = backlight_get_brightness(bd); |
63 | int ret; |
64 | |
65 | if ((brightness < 0) || (bd->props.max_brightness < brightness)) { |
66 | dev_err(&bd->dev, "invalid brightness, %d\n" , brightness); |
67 | return -EINVAL; |
68 | } |
69 | |
70 | dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n" , |
71 | bd->props.brightness, bd->props.power, bd->props.state); |
72 | |
73 | ret = aat2870->write(aat2870, AAT2870_BLM, |
74 | (u8)aat2870_brightness(aat2870_bl, brightness)); |
75 | if (ret < 0) |
76 | return ret; |
77 | |
78 | if (brightness == 0) { |
79 | ret = aat2870_bl_disable(aat2870_bl); |
80 | if (ret < 0) |
81 | return ret; |
82 | } else if (aat2870_bl->brightness == 0) { |
83 | ret = aat2870_bl_enable(aat2870_bl); |
84 | if (ret < 0) |
85 | return ret; |
86 | } |
87 | |
88 | aat2870_bl->brightness = brightness; |
89 | |
90 | return 0; |
91 | } |
92 | |
93 | static int aat2870_bl_check_fb(struct backlight_device *bd, struct fb_info *fi) |
94 | { |
95 | return 1; |
96 | } |
97 | |
98 | static const struct backlight_ops aat2870_bl_ops = { |
99 | .options = BL_CORE_SUSPENDRESUME, |
100 | .update_status = aat2870_bl_update_status, |
101 | .check_fb = aat2870_bl_check_fb, |
102 | }; |
103 | |
104 | static int aat2870_bl_probe(struct platform_device *pdev) |
105 | { |
106 | struct aat2870_bl_platform_data *pdata = dev_get_platdata(dev: &pdev->dev); |
107 | struct aat2870_bl_driver_data *aat2870_bl; |
108 | struct backlight_device *bd; |
109 | struct backlight_properties props; |
110 | int ret = 0; |
111 | |
112 | if (!pdata) { |
113 | dev_err(&pdev->dev, "No platform data\n" ); |
114 | ret = -ENXIO; |
115 | goto out; |
116 | } |
117 | |
118 | if (pdev->id != AAT2870_ID_BL) { |
119 | dev_err(&pdev->dev, "Invalid device ID, %d\n" , pdev->id); |
120 | ret = -EINVAL; |
121 | goto out; |
122 | } |
123 | |
124 | aat2870_bl = devm_kzalloc(dev: &pdev->dev, |
125 | size: sizeof(struct aat2870_bl_driver_data), |
126 | GFP_KERNEL); |
127 | if (!aat2870_bl) { |
128 | ret = -ENOMEM; |
129 | goto out; |
130 | } |
131 | |
132 | memset(&props, 0, sizeof(struct backlight_properties)); |
133 | |
134 | props.type = BACKLIGHT_RAW; |
135 | bd = devm_backlight_device_register(dev: &pdev->dev, name: "aat2870-backlight" , |
136 | parent: &pdev->dev, devdata: aat2870_bl, ops: &aat2870_bl_ops, |
137 | props: &props); |
138 | if (IS_ERR(ptr: bd)) { |
139 | dev_err(&pdev->dev, |
140 | "Failed allocate memory for backlight device\n" ); |
141 | ret = PTR_ERR(ptr: bd); |
142 | goto out; |
143 | } |
144 | |
145 | aat2870_bl->pdev = pdev; |
146 | platform_set_drvdata(pdev, data: aat2870_bl); |
147 | |
148 | aat2870_bl->bd = bd; |
149 | |
150 | if (pdata->channels > 0) |
151 | aat2870_bl->channels = pdata->channels; |
152 | else |
153 | aat2870_bl->channels = AAT2870_BL_CH_ALL; |
154 | |
155 | if (pdata->max_current > 0) |
156 | aat2870_bl->max_current = pdata->max_current; |
157 | else |
158 | aat2870_bl->max_current = AAT2870_CURRENT_27_9; |
159 | |
160 | if (pdata->max_brightness > 0) |
161 | bd->props.max_brightness = pdata->max_brightness; |
162 | else |
163 | bd->props.max_brightness = 255; |
164 | |
165 | aat2870_bl->brightness = 0; |
166 | bd->props.power = FB_BLANK_UNBLANK; |
167 | bd->props.brightness = bd->props.max_brightness; |
168 | |
169 | ret = aat2870_bl_update_status(bd); |
170 | if (ret < 0) { |
171 | dev_err(&pdev->dev, "Failed to initialize\n" ); |
172 | return ret; |
173 | } |
174 | |
175 | return 0; |
176 | |
177 | out: |
178 | return ret; |
179 | } |
180 | |
181 | static void aat2870_bl_remove(struct platform_device *pdev) |
182 | { |
183 | struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev); |
184 | struct backlight_device *bd = aat2870_bl->bd; |
185 | |
186 | bd->props.power = FB_BLANK_POWERDOWN; |
187 | bd->props.brightness = 0; |
188 | backlight_update_status(bd); |
189 | } |
190 | |
191 | static struct platform_driver aat2870_bl_driver = { |
192 | .driver = { |
193 | .name = "aat2870-backlight" , |
194 | }, |
195 | .probe = aat2870_bl_probe, |
196 | .remove_new = aat2870_bl_remove, |
197 | }; |
198 | |
199 | static int __init aat2870_bl_init(void) |
200 | { |
201 | return platform_driver_register(&aat2870_bl_driver); |
202 | } |
203 | subsys_initcall(aat2870_bl_init); |
204 | |
205 | static void __exit aat2870_bl_exit(void) |
206 | { |
207 | platform_driver_unregister(&aat2870_bl_driver); |
208 | } |
209 | module_exit(aat2870_bl_exit); |
210 | |
211 | MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight" ); |
212 | MODULE_LICENSE("GPL" ); |
213 | MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>" ); |
214 | |