2 * Backlight driver for Marvell Semiconductor 88PM8606
4 * Copyright (C) 2009 Marvell International Ltd.
5 * Haojian Zhuang <haojian.zhuang@marvell.com>
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.
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
17 #include <linux/i2c.h>
18 #include <linux/backlight.h>
19 #include <linux/mfd/88pm860x.h>
20 #include <linux/module.h>
22 #define MAX_BRIGHTNESS (0xFF)
23 #define MIN_BRIGHTNESS (0)
25 #define CURRENT_BITMASK (0x1F << 1)
27 struct pm860x_backlight_data {
28 struct pm860x_chip *chip;
29 struct i2c_client *i2c;
30 int current_brightness;
36 static inline int wled_a(int port)
40 ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;
44 static inline int wled_b(int port)
48 ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
52 /* WLED2 & WLED3 share the same IDC */
53 static inline int wled_idc(int port)
58 case PM8606_BACKLIGHT1:
59 case PM8606_BACKLIGHT2:
60 ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
62 case PM8606_BACKLIGHT3:
64 ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;
70 static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
72 struct pm860x_backlight_data *data = bl_get_data(bl);
73 struct pm860x_chip *chip = data->chip;
77 if (brightness > MAX_BRIGHTNESS)
78 value = MAX_BRIGHTNESS;
82 ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);
86 if ((data->current_brightness == 0) && brightness) {
88 ret = pm860x_set_bits(data->i2c, wled_idc(data->port),
89 CURRENT_BITMASK, data->iset);
94 ret = pm860x_set_bits(data->i2c, PM8606_PWM,
95 PM8606_PWM_FREQ_MASK, data->pwm);
99 if (brightness == MAX_BRIGHTNESS) {
100 /* set WLED_ON bit as 100% */
101 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
102 PM8606_WLED_ON, PM8606_WLED_ON);
105 if (brightness == MAX_BRIGHTNESS) {
106 /* set WLED_ON bit as 100% */
107 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
108 PM8606_WLED_ON, PM8606_WLED_ON);
110 /* clear WLED_ON bit since it's not 100% */
111 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
118 dev_dbg(chip->dev, "set brightness %d\n", value);
119 data->current_brightness = value;
122 dev_dbg(chip->dev, "set brightness %d failure with return "
123 "value:%d\n", value, ret);
127 static int pm860x_backlight_update_status(struct backlight_device *bl)
129 int brightness = bl->props.brightness;
131 if (bl->props.power != FB_BLANK_UNBLANK)
134 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
137 if (bl->props.state & BL_CORE_SUSPENDED)
140 return pm860x_backlight_set(bl, brightness);
143 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
145 struct pm860x_backlight_data *data = bl_get_data(bl);
146 struct pm860x_chip *chip = data->chip;
149 ret = pm860x_reg_read(data->i2c, wled_a(data->port));
152 data->current_brightness = ret;
153 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
154 return data->current_brightness;
159 static const struct backlight_ops pm860x_backlight_ops = {
160 .options = BL_CORE_SUSPENDRESUME,
161 .update_status = pm860x_backlight_update_status,
162 .get_brightness = pm860x_backlight_get_brightness,
165 static int pm860x_backlight_probe(struct platform_device *pdev)
167 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
168 struct pm860x_backlight_pdata *pdata = NULL;
169 struct pm860x_backlight_data *data;
170 struct backlight_device *bl;
171 struct resource *res;
172 struct backlight_properties props;
174 char name[MFD_NAME_SIZE];
177 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
179 dev_err(&pdev->dev, "No I/O resource!\n");
183 pdata = pdev->dev.platform_data;
185 dev_err(&pdev->dev, "platform data isn't assigned to "
190 data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
194 strncpy(name, res->name, MFD_NAME_SIZE);
196 data->i2c = (chip->id == CHIP_PM8606) ? chip->client \
198 data->current_brightness = MAX_BRIGHTNESS;
199 data->pwm = pdata->pwm;
200 data->iset = pdata->iset;
201 data->port = pdata->flags;
202 if (data->port < 0) {
203 dev_err(&pdev->dev, "wrong platform data is assigned");
207 memset(&props, 0, sizeof(struct backlight_properties));
208 props.type = BACKLIGHT_RAW;
209 props.max_brightness = MAX_BRIGHTNESS;
210 bl = backlight_device_register(name, &pdev->dev, data,
211 &pm860x_backlight_ops, &props);
213 dev_err(&pdev->dev, "failed to register backlight\n");
216 bl->props.brightness = MAX_BRIGHTNESS;
218 platform_set_drvdata(pdev, bl);
220 /* Enable reference VSYS */
221 ret = pm860x_reg_read(data->i2c, PM8606_VSYS);
224 if ((ret & PM8606_VSYS_EN) == 0) {
225 value = ret | PM8606_VSYS_EN;
226 ret = pm860x_reg_write(data->i2c, PM8606_VSYS, value);
230 /* Enable reference OSC */
231 ret = pm860x_reg_read(data->i2c, PM8606_MISC);
234 if ((ret & PM8606_MISC_OSC_EN) == 0) {
235 value = ret | PM8606_MISC_OSC_EN;
236 ret = pm860x_reg_write(data->i2c, PM8606_MISC, value);
240 /* read current backlight */
241 ret = pm860x_backlight_get_brightness(bl);
245 backlight_update_status(bl);
248 backlight_device_unregister(bl);
252 static int pm860x_backlight_remove(struct platform_device *pdev)
254 struct backlight_device *bl = platform_get_drvdata(pdev);
256 backlight_device_unregister(bl);
260 static struct platform_driver pm860x_backlight_driver = {
262 .name = "88pm860x-backlight",
263 .owner = THIS_MODULE,
265 .probe = pm860x_backlight_probe,
266 .remove = pm860x_backlight_remove,
269 module_platform_driver(pm860x_backlight_driver);
271 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
272 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
273 MODULE_LICENSE("GPL");
274 MODULE_ALIAS("platform:88pm860x-backlight");