Merge tag 'v3.8-rc3' into v4l_for_linus
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / video / backlight / 88pm860x_bl.c
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1/*
2 * Backlight driver for Marvell Semiconductor 88PM8606
3 *
4 * Copyright (C) 2009 Marvell International Ltd.
5 * Haojian Zhuang <haojian.zhuang@marvell.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/init.h>
13#include <linux/kernel.h>
2e57d567 14#include <linux/of.h>
d07e8bf8 15#include <linux/platform_device.h>
adb70483 16#include <linux/slab.h>
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17#include <linux/fb.h>
18#include <linux/i2c.h>
19#include <linux/backlight.h>
20#include <linux/mfd/88pm860x.h>
355b200b 21#include <linux/module.h>
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22
23#define MAX_BRIGHTNESS (0xFF)
24#define MIN_BRIGHTNESS (0)
25
2550326a 26#define CURRENT_BITMASK (0x1F << 1)
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27
28struct pm860x_backlight_data {
29 struct pm860x_chip *chip;
30 struct i2c_client *i2c;
31 int current_brightness;
32 int port;
33 int pwm;
34 int iset;
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35 int reg_duty_cycle;
36 int reg_always_on;
37 int reg_current;
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38};
39
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40static int backlight_power_set(struct pm860x_chip *chip, int port,
41 int on)
42{
43 int ret = -EINVAL;
44
45 switch (port) {
a6ccdcd9 46 case 0:
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47 ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
48 pm8606_osc_disable(chip, WLED1_DUTY);
49 break;
a6ccdcd9 50 case 1:
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51 ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
52 pm8606_osc_disable(chip, WLED2_DUTY);
53 break;
a6ccdcd9 54 case 2:
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55 ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
56 pm8606_osc_disable(chip, WLED3_DUTY);
57 break;
58 }
59 return ret;
60}
61
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62static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
63{
64 struct pm860x_backlight_data *data = bl_get_data(bl);
65 struct pm860x_chip *chip = data->chip;
66 unsigned char value;
67 int ret;
68
69 if (brightness > MAX_BRIGHTNESS)
70 value = MAX_BRIGHTNESS;
71 else
72 value = brightness;
73
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74 if (brightness)
75 backlight_power_set(chip, data->port, 1);
76
a6ccdcd9 77 ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
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78 if (ret < 0)
79 goto out;
80
81 if ((data->current_brightness == 0) && brightness) {
82 if (data->iset) {
a6ccdcd9 83 ret = pm860x_set_bits(data->i2c, data->reg_current,
2550326a 84 CURRENT_BITMASK, data->iset);
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85 if (ret < 0)
86 goto out;
87 }
88 if (data->pwm) {
89 ret = pm860x_set_bits(data->i2c, PM8606_PWM,
90 PM8606_PWM_FREQ_MASK, data->pwm);
91 if (ret < 0)
92 goto out;
93 }
94 if (brightness == MAX_BRIGHTNESS) {
95 /* set WLED_ON bit as 100% */
a6ccdcd9 96 ret = pm860x_set_bits(data->i2c, data->reg_always_on,
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97 PM8606_WLED_ON, PM8606_WLED_ON);
98 }
99 } else {
100 if (brightness == MAX_BRIGHTNESS) {
101 /* set WLED_ON bit as 100% */
a6ccdcd9 102 ret = pm860x_set_bits(data->i2c, data->reg_always_on,
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103 PM8606_WLED_ON, PM8606_WLED_ON);
104 } else {
105 /* clear WLED_ON bit since it's not 100% */
a6ccdcd9 106 ret = pm860x_set_bits(data->i2c, data->reg_always_on,
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107 PM8606_WLED_ON, 0);
108 }
109 }
110 if (ret < 0)
111 goto out;
112
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113 if (brightness == 0)
114 backlight_power_set(chip, data->port, 0);
115
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116 dev_dbg(chip->dev, "set brightness %d\n", value);
117 data->current_brightness = value;
118 return 0;
119out:
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120 dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
121 value, ret);
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122 return ret;
123}
124
125static int pm860x_backlight_update_status(struct backlight_device *bl)
126{
127 int brightness = bl->props.brightness;
128
129 if (bl->props.power != FB_BLANK_UNBLANK)
130 brightness = 0;
131
132 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
133 brightness = 0;
134
135 if (bl->props.state & BL_CORE_SUSPENDED)
136 brightness = 0;
137
138 return pm860x_backlight_set(bl, brightness);
139}
140
141static int pm860x_backlight_get_brightness(struct backlight_device *bl)
142{
143 struct pm860x_backlight_data *data = bl_get_data(bl);
144 struct pm860x_chip *chip = data->chip;
145 int ret;
146
a6ccdcd9 147 ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
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148 if (ret < 0)
149 goto out;
150 data->current_brightness = ret;
151 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
152 return data->current_brightness;
153out:
154 return -EINVAL;
155}
156
acc2472e 157static const struct backlight_ops pm860x_backlight_ops = {
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158 .options = BL_CORE_SUSPENDRESUME,
159 .update_status = pm860x_backlight_update_status,
160 .get_brightness = pm860x_backlight_get_brightness,
161};
162
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163#ifdef CONFIG_OF
164static int pm860x_backlight_dt_init(struct platform_device *pdev,
165 struct pm860x_backlight_data *data,
166 char *name)
167{
168 struct device_node *nproot = pdev->dev.parent->of_node, *np;
169 int iset = 0;
170 if (!nproot)
171 return -ENODEV;
172 nproot = of_find_node_by_name(nproot, "backlights");
173 if (!nproot) {
174 dev_err(&pdev->dev, "failed to find backlights node\n");
175 return -ENODEV;
176 }
177 for_each_child_of_node(nproot, np) {
178 if (!of_node_cmp(np->name, name)) {
179 of_property_read_u32(np, "marvell,88pm860x-iset",
180 &iset);
181 data->iset = PM8606_WLED_CURRENT(iset);
182 of_property_read_u32(np, "marvell,88pm860x-pwm",
183 &data->pwm);
184 break;
185 }
186 }
187 return 0;
188}
189#else
190#define pm860x_backlight_dt_init(x, y, z) (-1)
191#endif
192
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193static int pm860x_backlight_probe(struct platform_device *pdev)
194{
195 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
a6ccdcd9 196 struct pm860x_backlight_pdata *pdata = pdev->dev.platform_data;
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197 struct pm860x_backlight_data *data;
198 struct backlight_device *bl;
199 struct resource *res;
a19a6ee6 200 struct backlight_properties props;
d07e8bf8 201 char name[MFD_NAME_SIZE];
a6ccdcd9 202 int ret = 0;
d07e8bf8 203
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204 data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
205 GFP_KERNEL);
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206 if (data == NULL)
207 return -ENOMEM;
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208 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
209 if (!res) {
210 dev_err(&pdev->dev, "No REG resource for duty cycle\n");
3a1f9462 211 return -ENXIO;
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212 }
213 data->reg_duty_cycle = res->start;
214 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
215 if (!res) {
216 dev_err(&pdev->dev, "No REG resorce for always on\n");
3a1f9462 217 return -ENXIO;
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218 }
219 data->reg_always_on = res->start;
220 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
221 if (!res) {
222 dev_err(&pdev->dev, "No REG resource for current\n");
3a1f9462 223 return -ENXIO;
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224 }
225 data->reg_current = res->start;
226
227 memset(name, 0, MFD_NAME_SIZE);
228 sprintf(name, "backlight-%d", pdev->id);
229 data->port = pdev->id;
d07e8bf8 230 data->chip = chip;
2fe2380e 231 data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
d07e8bf8 232 data->current_brightness = MAX_BRIGHTNESS;
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233 if (pm860x_backlight_dt_init(pdev, data, name)) {
234 if (pdata) {
235 data->pwm = pdata->pwm;
236 data->iset = pdata->iset;
237 }
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238 }
239
a19a6ee6 240 memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747 241 props.type = BACKLIGHT_RAW;
a19a6ee6 242 props.max_brightness = MAX_BRIGHTNESS;
d07e8bf8 243 bl = backlight_device_register(name, &pdev->dev, data,
a19a6ee6 244 &pm860x_backlight_ops, &props);
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245 if (IS_ERR(bl)) {
246 dev_err(&pdev->dev, "failed to register backlight\n");
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247 return PTR_ERR(bl);
248 }
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249 bl->props.brightness = MAX_BRIGHTNESS;
250
251 platform_set_drvdata(pdev, bl);
252
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253 /* read current backlight */
254 ret = pm860x_backlight_get_brightness(bl);
255 if (ret < 0)
a6ccdcd9 256 goto out_brt;
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257
258 backlight_update_status(bl);
259 return 0;
a6ccdcd9 260out_brt:
1f976996 261 backlight_device_unregister(bl);
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262 return ret;
263}
264
265static int pm860x_backlight_remove(struct platform_device *pdev)
266{
267 struct backlight_device *bl = platform_get_drvdata(pdev);
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268
269 backlight_device_unregister(bl);
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270 return 0;
271}
272
273static struct platform_driver pm860x_backlight_driver = {
274 .driver = {
275 .name = "88pm860x-backlight",
276 .owner = THIS_MODULE,
277 },
278 .probe = pm860x_backlight_probe,
279 .remove = pm860x_backlight_remove,
280};
281
81178e02 282module_platform_driver(pm860x_backlight_driver);
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283
284MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
285MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
286MODULE_LICENSE("GPL");
287MODULE_ALIAS("platform:88pm860x-backlight");