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Source at commit edfd9f4 created 13 years 4 months ago. By Xiangfu Liu, [linux] support increase/decrease in screen brightness | |
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1 | /* |
2 | * Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.de> |
3 | * JZ4720/JZ4740 SoC LCD framebuffer driver |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify it |
6 | * under the terms of the GNU General Public License as published by the |
7 | * Free Software Foundation; either version 2 of the License, or (at your |
8 | * option) any later version. |
9 | * |
10 | * You should have received a copy of the GNU General Public License along |
11 | * with this program; if not, write to the Free Software Foundation, Inc., |
12 | * 675 Mass Ave, Cambridge, MA 02139, USA. |
13 | * |
14 | */ |
15 | |
16 | #include <linux/module.h> |
17 | #include <linux/spi/spi.h> |
18 | #include <linux/lcd.h> |
19 | #include <linux/backlight.h> |
20 | #include <linux/delay.h> |
21 | |
22 | struct gpm940b0 { |
23 | struct spi_device *spi; |
24 | struct lcd_device *lcd; |
25 | struct backlight_device *bl; |
26 | unsigned enabled:1; |
27 | }; |
28 | |
29 | static int gpm940b0_write_reg(struct spi_device *spi, uint8_t reg, |
30 | uint8_t data) |
31 | { |
32 | uint8_t buf[2]; |
33 | buf[0] = ((reg & 0x40) << 1) | (reg & 0x3f); |
34 | buf[1] = data; |
35 | |
36 | return spi_write(spi, buf, sizeof(buf)); |
37 | } |
38 | |
39 | static void gpm940b0_power_disable(struct gpm940b0 *gpm940b0) |
40 | { |
41 | int ret = gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc6) ; |
42 | if (ret < 0) |
43 | printk("Failed to disable power: %d\n", ret); |
44 | } |
45 | |
46 | static void gpm940b0_power_enable(struct gpm940b0 *gpm940b0) |
47 | { |
48 | gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc7); |
49 | } |
50 | |
51 | |
52 | static int gpm940b0_set_power(struct lcd_device *lcd, int power) |
53 | { |
54 | struct gpm940b0 *gpm940b0 = lcd_get_data(lcd); |
55 | |
56 | switch (power) { |
57 | case FB_BLANK_UNBLANK: |
58 | mdelay(20); |
59 | gpm940b0->enabled = 1; |
60 | gpm940b0_power_enable(gpm940b0); |
61 | break; |
62 | default: |
63 | gpm940b0->enabled = 0; |
64 | gpm940b0_power_disable(gpm940b0); |
65 | mdelay(20); |
66 | break; |
67 | } |
68 | return 0; |
69 | } |
70 | |
71 | static int gpm940b0_set_contrast(struct lcd_device *lcd, int contrast) |
72 | { |
73 | struct gpm940b0 *gpm940b0 = lcd_get_data(lcd); |
74 | gpm940b0_write_reg(gpm940b0->spi, 0x0d, contrast); |
75 | return 0; |
76 | } |
77 | |
78 | static int gpm940b0_set_mode(struct lcd_device *lcd, struct fb_videomode *mode) |
79 | { |
80 | if (mode->xres != 320 && mode->yres != 240) |
81 | return -EINVAL; |
82 | |
83 | return 0; |
84 | } |
85 | |
86 | int gpm940b0_bl_get_brightness(struct backlight_device *bl) |
87 | { |
88 | return bl->props.brightness; |
89 | } |
90 | |
91 | int gpm940b0_bl_update_status(struct backlight_device *bl) |
92 | { |
93 | struct gpm940b0 *gpm940b0 = bl_get_data(bl); |
94 | |
95 | gpm940b0_write_reg(gpm940b0->spi, 0x3, (bl->props.brightness)); |
96 | |
97 | return 0; |
98 | } |
99 | |
100 | static ssize_t reg_write(struct device *dev, struct device_attribute *attr, |
101 | const char *buf, size_t count) |
102 | { |
103 | char *buf2; |
104 | uint32_t reg = simple_strtoul(buf, &buf2, 10); |
105 | uint32_t val = simple_strtoul(buf2 + 1, NULL, 10); |
106 | struct gpm940b0 *gpm940b0 = dev_get_drvdata(dev); |
107 | |
108 | if (reg < 0 || val < 0) |
109 | return -EINVAL; |
110 | |
111 | gpm940b0_write_reg(gpm940b0->spi, reg, val); |
112 | return count; |
113 | } |
114 | |
115 | static DEVICE_ATTR(reg, 0644, NULL, reg_write); |
116 | |
117 | static struct lcd_ops gpm940b0_lcd_ops = { |
118 | .set_power = gpm940b0_set_power, |
119 | .set_contrast = gpm940b0_set_contrast, |
120 | .set_mode = gpm940b0_set_mode, |
121 | }; |
122 | |
123 | static struct backlight_ops gpm940b0_bl_ops = { |
124 | .get_brightness = gpm940b0_bl_get_brightness, |
125 | .update_status = gpm940b0_bl_update_status, |
126 | }; |
127 | |
128 | static int __devinit gpm940b0_probe(struct spi_device *spi) |
129 | { |
130 | int ret; |
131 | struct gpm940b0 *gpm940b0; |
132 | |
133 | gpm940b0 = kmalloc(sizeof(*gpm940b0), GFP_KERNEL); |
134 | |
135 | spi->bits_per_word = 8; |
136 | |
137 | ret = spi_setup(spi); |
138 | if (ret) { |
139 | dev_err(&spi->dev, "Failed to setup spi\n"); |
140 | goto err_free_gpm940b0; |
141 | } |
142 | |
143 | gpm940b0->spi = spi; |
144 | |
145 | gpm940b0->lcd = lcd_device_register("gpm940b0-lcd", &spi->dev, gpm940b0, |
146 | &gpm940b0_lcd_ops); |
147 | |
148 | if (IS_ERR(gpm940b0->lcd)) { |
149 | ret = PTR_ERR(gpm940b0->lcd); |
150 | dev_err(&spi->dev, "Failed to register lcd device: %d\n", ret); |
151 | goto err_free_gpm940b0; |
152 | } |
153 | |
154 | gpm940b0->lcd->props.max_contrast = 255; |
155 | |
156 | gpm940b0->bl = backlight_device_register("gpm940b0-bl", &spi->dev, gpm940b0, |
157 | &gpm940b0_bl_ops); |
158 | |
159 | if (IS_ERR(gpm940b0->bl)) { |
160 | ret = PTR_ERR(gpm940b0->bl); |
161 | dev_err(&spi->dev, "Failed to register backlight device: %d\n", ret); |
162 | gpm940b0->bl = NULL; |
163 | } else { |
164 | gpm940b0->bl->props.max_brightness = 255; |
165 | gpm940b0->bl->props.brightness = 64; |
166 | gpm940b0->bl->props.power = FB_BLANK_UNBLANK; |
167 | } |
168 | backlight_update_status(gpm940b0->bl); |
169 | |
170 | ret = device_create_file(&spi->dev, &dev_attr_reg); |
171 | if (ret) |
172 | goto err_unregister_lcd; |
173 | |
174 | gpm940b0->enabled = 1; |
175 | dev_set_drvdata(&spi->dev, gpm940b0); |
176 | |
177 | gpm940b0_write_reg(spi, 0x07, 0x8d); |
178 | gpm940b0_write_reg(spi, 0x13, 0x01); |
179 | gpm940b0_write_reg(spi, 0x5, 0xc7); |
180 | return 0; |
181 | err_unregister_lcd: |
182 | lcd_device_unregister(gpm940b0->lcd); |
183 | err_free_gpm940b0: |
184 | kfree(gpm940b0); |
185 | return ret; |
186 | } |
187 | |
188 | static int __devexit gpm940b0_remove(struct spi_device *spi) |
189 | { |
190 | struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi); |
191 | if (gpm940b0->bl) |
192 | backlight_device_unregister(gpm940b0->bl); |
193 | |
194 | lcd_device_unregister(gpm940b0->lcd); |
195 | |
196 | spi_set_drvdata(spi, NULL); |
197 | kfree(gpm940b0); |
198 | return 0; |
199 | } |
200 | |
201 | #ifdef CONFIG_PM |
202 | |
203 | static int gpm940b0_suspend(struct spi_device *spi, pm_message_t state) |
204 | { |
205 | struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi); |
206 | if (gpm940b0->enabled) { |
207 | gpm940b0_power_disable(gpm940b0); |
208 | mdelay(10); |
209 | } |
210 | return 0; |
211 | } |
212 | |
213 | static int gpm940b0_resume(struct spi_device *spi) |
214 | { |
215 | struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi); |
216 | if (gpm940b0->enabled) |
217 | gpm940b0_power_enable(gpm940b0); |
218 | return 0; |
219 | } |
220 | |
221 | #else |
222 | #define gpm940b0_suspend NULL |
223 | #define gpm940b0_resume NULL |
224 | #endif |
225 | |
226 | static struct spi_driver gpm940b0_driver = { |
227 | .driver = { |
228 | .name = "gpm940b0", |
229 | .owner = THIS_MODULE, |
230 | }, |
231 | .probe = gpm940b0_probe, |
232 | .remove = __devexit_p(gpm940b0_remove), |
233 | .suspend = gpm940b0_suspend, |
234 | .resume = gpm940b0_resume, |
235 | }; |
236 | |
237 | static int __init gpm940b0_init(void) |
238 | { |
239 | return spi_register_driver(&gpm940b0_driver); |
240 | } |
241 | module_init(gpm940b0_init); |
242 | |
243 | static void __exit gpm940b0_exit(void) |
244 | { |
245 | return spi_unregister_driver(&gpm940b0_driver); |
246 | } |
247 | module_exit(gpm940b0_exit) |
248 | |
249 | MODULE_AUTHOR("Lars-Peter Clausen"); |
250 | MODULE_LICENSE("GPL v2"); |
251 | MODULE_DESCRIPTION("LCD and backlight controll for Giantplus GPM940B0"); |
252 | MODULE_ALIAS("spi:gpm940b0"); |
253 |