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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 | ||
70 | static int aat2870_bl_get_brightness(struct backlight_device *bd) | |
71 | { | |
72 | return bd->props.brightness; | |
73 | } | |
74 | ||
75 | static int aat2870_bl_update_status(struct backlight_device *bd) | |
76 | { | |
76cb2598 | 77 | struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd); |
4b0d711b JP |
78 | struct aat2870_data *aat2870 = |
79 | dev_get_drvdata(aat2870_bl->pdev->dev.parent); | |
80 | int brightness = bd->props.brightness; | |
81 | int ret; | |
82 | ||
83 | if ((brightness < 0) || (bd->props.max_brightness < brightness)) { | |
84 | dev_err(&bd->dev, "invalid brightness, %d\n", brightness); | |
85 | return -EINVAL; | |
86 | } | |
87 | ||
88 | dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n", | |
89 | bd->props.brightness, bd->props.power, bd->props.state); | |
90 | ||
91 | if ((bd->props.power != FB_BLANK_UNBLANK) || | |
92 | (bd->props.state & BL_CORE_FBBLANK) || | |
93 | (bd->props.state & BL_CORE_SUSPENDED)) | |
94 | brightness = 0; | |
95 | ||
96 | ret = aat2870->write(aat2870, AAT2870_BLM, | |
97 | (u8)aat2870_brightness(aat2870_bl, brightness)); | |
98 | if (ret < 0) | |
99 | return ret; | |
100 | ||
101 | if (brightness == 0) { | |
102 | ret = aat2870_bl_disable(aat2870_bl); | |
103 | if (ret < 0) | |
104 | return ret; | |
105 | } else if (aat2870_bl->brightness == 0) { | |
106 | ret = aat2870_bl_enable(aat2870_bl); | |
107 | if (ret < 0) | |
108 | return ret; | |
109 | } | |
110 | ||
111 | aat2870_bl->brightness = brightness; | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static int aat2870_bl_check_fb(struct backlight_device *bd, struct fb_info *fi) | |
117 | { | |
118 | return 1; | |
119 | } | |
120 | ||
121 | static const struct backlight_ops aat2870_bl_ops = { | |
122 | .options = BL_CORE_SUSPENDRESUME, | |
123 | .get_brightness = aat2870_bl_get_brightness, | |
124 | .update_status = aat2870_bl_update_status, | |
125 | .check_fb = aat2870_bl_check_fb, | |
126 | }; | |
127 | ||
128 | static int aat2870_bl_probe(struct platform_device *pdev) | |
129 | { | |
130 | struct aat2870_bl_platform_data *pdata = pdev->dev.platform_data; | |
131 | struct aat2870_bl_driver_data *aat2870_bl; | |
132 | struct backlight_device *bd; | |
133 | struct backlight_properties props; | |
134 | int ret = 0; | |
135 | ||
136 | if (!pdata) { | |
137 | dev_err(&pdev->dev, "No platform data\n"); | |
138 | ret = -ENXIO; | |
139 | goto out; | |
140 | } | |
141 | ||
142 | if (pdev->id != AAT2870_ID_BL) { | |
143 | dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id); | |
144 | ret = -EINVAL; | |
145 | goto out; | |
146 | } | |
147 | ||
ce969228 JL |
148 | aat2870_bl = devm_kzalloc(&pdev->dev, |
149 | sizeof(struct aat2870_bl_driver_data), | |
150 | GFP_KERNEL); | |
4b0d711b JP |
151 | if (!aat2870_bl) { |
152 | dev_err(&pdev->dev, | |
153 | "Failed to allocate memory for aat2870 backlight\n"); | |
154 | ret = -ENOMEM; | |
155 | goto out; | |
156 | } | |
157 | ||
158 | memset(&props, 0, sizeof(struct backlight_properties)); | |
159 | ||
160 | props.type = BACKLIGHT_RAW; | |
161 | bd = backlight_device_register("aat2870-backlight", &pdev->dev, | |
162 | aat2870_bl, &aat2870_bl_ops, &props); | |
4c4dd903 | 163 | if (IS_ERR(bd)) { |
4b0d711b JP |
164 | dev_err(&pdev->dev, |
165 | "Failed allocate memory for backlight device\n"); | |
4c4dd903 | 166 | ret = PTR_ERR(bd); |
ce969228 | 167 | goto out; |
4b0d711b JP |
168 | } |
169 | ||
170 | aat2870_bl->pdev = pdev; | |
171 | platform_set_drvdata(pdev, aat2870_bl); | |
172 | ||
173 | aat2870_bl->bd = bd; | |
174 | ||
175 | if (pdata->channels > 0) | |
176 | aat2870_bl->channels = pdata->channels; | |
177 | else | |
178 | aat2870_bl->channels = AAT2870_BL_CH_ALL; | |
179 | ||
5d6f921b | 180 | if (pdata->max_current > 0) |
4b0d711b JP |
181 | aat2870_bl->max_current = pdata->max_current; |
182 | else | |
183 | aat2870_bl->max_current = AAT2870_CURRENT_27_9; | |
184 | ||
185 | if (pdata->max_brightness > 0) | |
186 | bd->props.max_brightness = pdata->max_brightness; | |
187 | else | |
188 | bd->props.max_brightness = 255; | |
189 | ||
190 | aat2870_bl->brightness = 0; | |
191 | bd->props.power = FB_BLANK_UNBLANK; | |
192 | bd->props.brightness = bd->props.max_brightness; | |
193 | ||
194 | ret = aat2870_bl_update_status(bd); | |
195 | if (ret < 0) { | |
196 | dev_err(&pdev->dev, "Failed to initialize\n"); | |
197 | goto out_bl_dev_unregister; | |
198 | } | |
199 | ||
200 | return 0; | |
201 | ||
202 | out_bl_dev_unregister: | |
203 | backlight_device_unregister(bd); | |
4b0d711b JP |
204 | out: |
205 | return ret; | |
206 | } | |
207 | ||
208 | static int aat2870_bl_remove(struct platform_device *pdev) | |
209 | { | |
210 | struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev); | |
211 | struct backlight_device *bd = aat2870_bl->bd; | |
212 | ||
213 | bd->props.power = FB_BLANK_POWERDOWN; | |
214 | bd->props.brightness = 0; | |
215 | backlight_update_status(bd); | |
216 | ||
217 | backlight_device_unregister(bd); | |
4b0d711b JP |
218 | |
219 | return 0; | |
220 | } | |
221 | ||
222 | static struct platform_driver aat2870_bl_driver = { | |
223 | .driver = { | |
224 | .name = "aat2870-backlight", | |
225 | .owner = THIS_MODULE, | |
226 | }, | |
227 | .probe = aat2870_bl_probe, | |
228 | .remove = aat2870_bl_remove, | |
229 | }; | |
230 | ||
231 | static int __init aat2870_bl_init(void) | |
232 | { | |
233 | return platform_driver_register(&aat2870_bl_driver); | |
234 | } | |
235 | subsys_initcall(aat2870_bl_init); | |
236 | ||
237 | static void __exit aat2870_bl_exit(void) | |
238 | { | |
239 | platform_driver_unregister(&aat2870_bl_driver); | |
240 | } | |
241 | module_exit(aat2870_bl_exit); | |
242 | ||
243 | MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight"); | |
244 | MODULE_LICENSE("GPL"); | |
245 | MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>"); |