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>
21 #define MAX_BRIGHTNESS (0xFF)
22 #define MIN_BRIGHTNESS (0)
24 #define CURRENT_BITMASK (0x1F << 1)
26 struct pm860x_backlight_data {
27 struct pm860x_chip *chip;
28 struct i2c_client *i2c;
29 int current_brightness;
35 static inline int wled_a(int port)
39 ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;
43 static inline int wled_b(int port)
47 ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
51 /* WLED2 & WLED3 share the same IDC */
52 static inline int wled_idc(int port)
57 case PM8606_BACKLIGHT1:
58 case PM8606_BACKLIGHT2:
59 ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
61 case PM8606_BACKLIGHT3:
63 ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;
69 static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
71 struct pm860x_backlight_data *data = bl_get_data(bl);
72 struct pm860x_chip *chip = data->chip;
76 if (brightness > MAX_BRIGHTNESS)
77 value = MAX_BRIGHTNESS;
81 ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);
85 if ((data->current_brightness == 0) && brightness) {
87 ret = pm860x_set_bits(data->i2c, wled_idc(data->port),
88 CURRENT_BITMASK, data->iset);
93 ret = pm860x_set_bits(data->i2c, PM8606_PWM,
94 PM8606_PWM_FREQ_MASK, data->pwm);
98 if (brightness == MAX_BRIGHTNESS) {
99 /* set WLED_ON bit as 100% */
100 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
101 PM8606_WLED_ON, PM8606_WLED_ON);
104 if (brightness == MAX_BRIGHTNESS) {
105 /* set WLED_ON bit as 100% */
106 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
107 PM8606_WLED_ON, PM8606_WLED_ON);
109 /* clear WLED_ON bit since it's not 100% */
110 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
117 dev_dbg(chip->dev, "set brightness %d\n", value);
118 data->current_brightness = value;
121 dev_dbg(chip->dev, "set brightness %d failure with return "
122 "value:%d\n", value, ret);
126 static int pm860x_backlight_update_status(struct backlight_device *bl)
128 int brightness = bl->props.brightness;
130 if (bl->props.power != FB_BLANK_UNBLANK)
133 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
136 if (bl->props.state & BL_CORE_SUSPENDED)
139 return pm860x_backlight_set(bl, brightness);
142 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
144 struct pm860x_backlight_data *data = bl_get_data(bl);
145 struct pm860x_chip *chip = data->chip;
148 ret = pm860x_reg_read(data->i2c, wled_a(data->port));
151 data->current_brightness = ret;
152 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
153 return data->current_brightness;
158 static const struct backlight_ops pm860x_backlight_ops = {
159 .options = BL_CORE_SUSPENDRESUME,
160 .update_status = pm860x_backlight_update_status,
161 .get_brightness = pm860x_backlight_get_brightness,
164 static int pm860x_backlight_probe(struct platform_device *pdev)
166 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
167 struct pm860x_backlight_pdata *pdata = NULL;
168 struct pm860x_backlight_data *data;
169 struct backlight_device *bl;
170 struct resource *res;
171 struct backlight_properties props;
173 char name[MFD_NAME_SIZE];
176 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
178 dev_err(&pdev->dev, "No I/O resource!\n");
182 pdata = pdev->dev.platform_data;
184 dev_err(&pdev->dev, "platform data isn't assigned to "
189 data = kzalloc(sizeof(struct pm860x_backlight_data), GFP_KERNEL);
192 strncpy(name, res->name, MFD_NAME_SIZE);
194 data->i2c = (chip->id == CHIP_PM8606) ? chip->client \
196 data->current_brightness = MAX_BRIGHTNESS;
197 data->pwm = pdata->pwm;
198 data->iset = pdata->iset;
199 data->port = pdata->flags;
200 if (data->port < 0) {
201 dev_err(&pdev->dev, "wrong platform data is assigned");
206 memset(&props, 0, sizeof(struct backlight_properties));
207 props.type = BACKLIGHT_RAW;
208 props.max_brightness = MAX_BRIGHTNESS;
209 bl = backlight_device_register(name, &pdev->dev, data,
210 &pm860x_backlight_ops, &props);
212 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);
253 static int pm860x_backlight_remove(struct platform_device *pdev)
255 struct backlight_device *bl = platform_get_drvdata(pdev);
256 struct pm860x_backlight_data *data = bl_get_data(bl);
258 backlight_device_unregister(bl);
263 static struct platform_driver pm860x_backlight_driver = {
265 .name = "88pm860x-backlight",
266 .owner = THIS_MODULE,
268 .probe = pm860x_backlight_probe,
269 .remove = pm860x_backlight_remove,
272 static int __init pm860x_backlight_init(void)
274 return platform_driver_register(&pm860x_backlight_driver);
276 module_init(pm860x_backlight_init);
278 static void __exit pm860x_backlight_exit(void)
280 platform_driver_unregister(&pm860x_backlight_driver);
282 module_exit(pm860x_backlight_exit);
284 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
285 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
286 MODULE_LICENSE("GPL");
287 MODULE_ALIAS("platform:88pm860x-backlight");