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4b0d711b JP |
1 | /* |
2 | * linux/drivers/video/backlight/aat2870_bl.c | |
3 | * | |
4 | * Copyright (c) 2011, NVIDIA Corporation. | |
5 | * Author: Jin Park <jinyoungp@nvidia.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * version 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
19 | * 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/mutex.h> | |
27 | #include <linux/delay.h> | |
28 | #include <linux/fb.h> | |
29 | #include <linux/backlight.h> | |
30 | #include <linux/mfd/aat2870.h> | |
31 | ||
32 | struct aat2870_bl_driver_data { | |
33 | struct platform_device *pdev; | |
34 | struct backlight_device *bd; | |
35 | ||
36 | int channels; | |
37 | int max_current; | |
38 | int brightness; /* current brightness */ | |
39 | }; | |
40 | ||
41 | static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl, | |
42 | int brightness) | |
43 | { | |
44 | struct backlight_device *bd = aat2870_bl->bd; | |
45 | int val; | |
46 | ||
5d6f921b | 47 | val = brightness * (aat2870_bl->max_current - 1); |
4b0d711b JP |
48 | val /= bd->props.max_brightness; |
49 | ||
50 | return val; | |
51 | } | |
52 | ||
53 | static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl) | |
54 | { | |
55 | struct aat2870_data *aat2870 | |
56 | = dev_get_drvdata(aat2870_bl->pdev->dev.parent); | |
57 | ||
58 | return aat2870->write(aat2870, AAT2870_BL_CH_EN, | |
59 | (u8)aat2870_bl->channels); | |
60 | } | |
61 | ||
62 | static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl) | |
63 | { | |
64 | struct aat2870_data *aat2870 | |
65 | = dev_get_drvdata(aat2870_bl->pdev->dev.parent); | |
66 | ||
67 | return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0); | |
68 | } | |
69 | ||
4b0d711b JP |
70 | static int aat2870_bl_update_status(struct backlight_device *bd) |
71 | { | |
76cb2598 | 72 | struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd); |
4b0d711b JP |
73 | struct aat2870_data *aat2870 = |
74 | dev_get_drvdata(aat2870_bl->pdev->dev.parent); | |
75 | int brightness = bd->props.brightness; | |
76 | int ret; | |
77 | ||
78 | if ((brightness < 0) || (bd->props.max_brightness < brightness)) { | |
79 | dev_err(&bd->dev, "invalid brightness, %d\n", brightness); | |
80 | return -EINVAL; | |
81 | } | |
82 | ||
83 | dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n", | |
84 | bd->props.brightness, bd->props.power, bd->props.state); | |
85 | ||
86 | if ((bd->props.power != FB_BLANK_UNBLANK) || | |
87 | (bd->props.state & BL_CORE_FBBLANK) || | |
88 | (bd->props.state & BL_CORE_SUSPENDED)) | |
89 | brightness = 0; | |
90 | ||
91 | ret = aat2870->write(aat2870, AAT2870_BLM, | |
92 | (u8)aat2870_brightness(aat2870_bl, brightness)); | |
93 | if (ret < 0) | |
94 | return ret; | |
95 | ||
96 | if (brightness == 0) { | |
97 | ret = aat2870_bl_disable(aat2870_bl); | |
98 | if (ret < 0) | |
99 | return ret; | |
100 | } else if (aat2870_bl->brightness == 0) { | |
101 | ret = aat2870_bl_enable(aat2870_bl); | |
102 | if (ret < 0) | |
103 | return ret; | |
104 | } | |
105 | ||
106 | aat2870_bl->brightness = brightness; | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int aat2870_bl_check_fb(struct backlight_device *bd, struct fb_info *fi) | |
112 | { | |
113 | return 1; | |
114 | } | |
115 | ||
116 | static const struct backlight_ops aat2870_bl_ops = { | |
117 | .options = BL_CORE_SUSPENDRESUME, | |
4b0d711b JP |
118 | .update_status = aat2870_bl_update_status, |
119 | .check_fb = aat2870_bl_check_fb, | |
120 | }; | |
121 | ||
122 | static int aat2870_bl_probe(struct platform_device *pdev) | |
123 | { | |
c512794c | 124 | struct aat2870_bl_platform_data *pdata = dev_get_platdata(&pdev->dev); |
4b0d711b JP |
125 | struct aat2870_bl_driver_data *aat2870_bl; |
126 | struct backlight_device *bd; | |
127 | struct backlight_properties props; | |
128 | int ret = 0; | |
129 | ||
130 | if (!pdata) { | |
131 | dev_err(&pdev->dev, "No platform data\n"); | |
132 | ret = -ENXIO; | |
133 | goto out; | |
134 | } | |
135 | ||
136 | if (pdev->id != AAT2870_ID_BL) { | |
137 | dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id); | |
138 | ret = -EINVAL; | |
139 | goto out; | |
140 | } | |
141 | ||
ce969228 JL |
142 | aat2870_bl = devm_kzalloc(&pdev->dev, |
143 | sizeof(struct aat2870_bl_driver_data), | |
144 | GFP_KERNEL); | |
4b0d711b | 145 | if (!aat2870_bl) { |
4b0d711b JP |
146 | ret = -ENOMEM; |
147 | goto out; | |
148 | } | |
149 | ||
150 | memset(&props, 0, sizeof(struct backlight_properties)); | |
151 | ||
152 | props.type = BACKLIGHT_RAW; | |
c7a2bf3b JH |
153 | bd = devm_backlight_device_register(&pdev->dev, "aat2870-backlight", |
154 | &pdev->dev, aat2870_bl, &aat2870_bl_ops, | |
155 | &props); | |
4c4dd903 | 156 | if (IS_ERR(bd)) { |
4b0d711b JP |
157 | dev_err(&pdev->dev, |
158 | "Failed allocate memory for backlight device\n"); | |
4c4dd903 | 159 | ret = PTR_ERR(bd); |
ce969228 | 160 | goto out; |
4b0d711b JP |
161 | } |
162 | ||
163 | aat2870_bl->pdev = pdev; | |
164 | platform_set_drvdata(pdev, aat2870_bl); | |
165 | ||
166 | aat2870_bl->bd = bd; | |
167 | ||
168 | if (pdata->channels > 0) | |
169 | aat2870_bl->channels = pdata->channels; | |
170 | else | |
171 | aat2870_bl->channels = AAT2870_BL_CH_ALL; | |
172 | ||
5d6f921b | 173 | if (pdata->max_current > 0) |
4b0d711b JP |
174 | aat2870_bl->max_current = pdata->max_current; |
175 | else | |
176 | aat2870_bl->max_current = AAT2870_CURRENT_27_9; | |
177 | ||
178 | if (pdata->max_brightness > 0) | |
179 | bd->props.max_brightness = pdata->max_brightness; | |
180 | else | |
181 | bd->props.max_brightness = 255; | |
182 | ||
183 | aat2870_bl->brightness = 0; | |
184 | bd->props.power = FB_BLANK_UNBLANK; | |
185 | bd->props.brightness = bd->props.max_brightness; | |
186 | ||
187 | ret = aat2870_bl_update_status(bd); | |
188 | if (ret < 0) { | |
189 | dev_err(&pdev->dev, "Failed to initialize\n"); | |
c7a2bf3b | 190 | return ret; |
4b0d711b JP |
191 | } |
192 | ||
193 | return 0; | |
194 | ||
4b0d711b JP |
195 | out: |
196 | return ret; | |
197 | } | |
198 | ||
199 | static int aat2870_bl_remove(struct platform_device *pdev) | |
200 | { | |
201 | struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev); | |
202 | struct backlight_device *bd = aat2870_bl->bd; | |
203 | ||
204 | bd->props.power = FB_BLANK_POWERDOWN; | |
205 | bd->props.brightness = 0; | |
206 | backlight_update_status(bd); | |
207 | ||
4b0d711b JP |
208 | return 0; |
209 | } | |
210 | ||
211 | static struct platform_driver aat2870_bl_driver = { | |
212 | .driver = { | |
213 | .name = "aat2870-backlight", | |
4b0d711b JP |
214 | }, |
215 | .probe = aat2870_bl_probe, | |
216 | .remove = aat2870_bl_remove, | |
217 | }; | |
218 | ||
219 | static int __init aat2870_bl_init(void) | |
220 | { | |
221 | return platform_driver_register(&aat2870_bl_driver); | |
222 | } | |
223 | subsys_initcall(aat2870_bl_init); | |
224 | ||
225 | static void __exit aat2870_bl_exit(void) | |
226 | { | |
227 | platform_driver_unregister(&aat2870_bl_driver); | |
228 | } | |
229 | module_exit(aat2870_bl_exit); | |
230 | ||
231 | MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight"); | |
232 | MODULE_LICENSE("GPL"); | |
233 | MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>"); |