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>
16 #include <linux/i2c.h>
17 #include <linux/backlight.h>
18 #include <linux/mfd/88pm860x.h>
20 #define MAX_BRIGHTNESS (0xFF)
21 #define MIN_BRIGHTNESS (0)
23 #define CURRENT_MASK (0x1F << 1)
25 struct pm860x_backlight_data {
26 struct pm860x_chip *chip;
27 struct i2c_client *i2c;
28 int current_brightness;
34 static inline int wled_a(int port)
38 ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;
42 static inline int wled_b(int port)
46 ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
50 /* WLED2 & WLED3 share the same IDC */
51 static inline int wled_idc(int port)
56 case PM8606_BACKLIGHT1:
57 case PM8606_BACKLIGHT2:
58 ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
60 case PM8606_BACKLIGHT3:
62 ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;
68 static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
70 struct pm860x_backlight_data *data = bl_get_data(bl);
71 struct pm860x_chip *chip = data->chip;
75 if (brightness > MAX_BRIGHTNESS)
76 value = MAX_BRIGHTNESS;
80 ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);
84 if ((data->current_brightness == 0) && brightness) {
86 ret = pm860x_set_bits(data->i2c, wled_idc(data->port),
87 CURRENT_MASK, data->iset);
92 ret = pm860x_set_bits(data->i2c, PM8606_PWM,
93 PM8606_PWM_FREQ_MASK, data->pwm);
97 if (brightness == MAX_BRIGHTNESS) {
98 /* set WLED_ON bit as 100% */
99 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
100 PM8606_WLED_ON, PM8606_WLED_ON);
103 if (brightness == MAX_BRIGHTNESS) {
104 /* set WLED_ON bit as 100% */
105 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
106 PM8606_WLED_ON, PM8606_WLED_ON);
108 /* clear WLED_ON bit since it's not 100% */
109 ret = pm860x_set_bits(data->i2c, wled_b(data->port),
116 dev_dbg(chip->dev, "set brightness %d\n", value);
117 data->current_brightness = value;
120 dev_dbg(chip->dev, "set brightness %d failure with return "
121 "value:%d\n", value, ret);
125 static int pm860x_backlight_update_status(struct backlight_device *bl)
127 int brightness = bl->props.brightness;
129 if (bl->props.power != FB_BLANK_UNBLANK)
132 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
135 if (bl->props.state & BL_CORE_SUSPENDED)
138 return pm860x_backlight_set(bl, brightness);
141 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
143 struct pm860x_backlight_data *data = bl_get_data(bl);
144 struct pm860x_chip *chip = data->chip;
147 ret = pm860x_reg_read(data->i2c, wled_a(data->port));
150 data->current_brightness = ret;
151 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
152 return data->current_brightness;
157 static struct backlight_ops pm860x_backlight_ops = {
158 .options = BL_CORE_SUSPENDRESUME,
159 .update_status = pm860x_backlight_update_status,
160 .get_brightness = pm860x_backlight_get_brightness,
163 static int __check_device(struct pm860x_backlight_pdata *pdata, char *name)
165 struct pm860x_backlight_pdata *p = pdata;
169 if ((p->id != PM8606_ID_BACKLIGHT) || (p->flags < 0))
172 if (!strncmp(name, pm860x_backlight_name[p->flags],
182 static int pm860x_backlight_probe(struct platform_device *pdev)
184 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
185 struct pm860x_platform_data *pm860x_pdata;
186 struct pm860x_backlight_pdata *pdata = NULL;
187 struct pm860x_backlight_data *data;
188 struct backlight_device *bl;
189 struct resource *res;
190 struct backlight_properties props;
192 char name[MFD_NAME_SIZE];
195 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
197 dev_err(&pdev->dev, "No I/O resource!\n");
201 if (pdev->dev.parent->platform_data) {
202 pm860x_pdata = pdev->dev.parent->platform_data;
203 pdata = pm860x_pdata->backlight;
206 dev_err(&pdev->dev, "platform data isn't assigned to "
211 data = kzalloc(sizeof(struct pm860x_backlight_data), GFP_KERNEL);
214 strncpy(name, res->name, MFD_NAME_SIZE);
216 data->i2c = (chip->id == CHIP_PM8606) ? chip->client \
218 data->current_brightness = MAX_BRIGHTNESS;
219 data->pwm = pdata->pwm;
220 data->iset = pdata->iset;
221 data->port = __check_device(pdata, name);
222 if (data->port < 0) {
223 dev_err(&pdev->dev, "wrong platform data is assigned");
227 memset(&props, 0, sizeof(struct backlight_properties));
228 props.max_brightness = MAX_BRIGHTNESS;
229 bl = backlight_device_register(name, &pdev->dev, data,
230 &pm860x_backlight_ops, &props);
232 dev_err(&pdev->dev, "failed to register backlight\n");
236 bl->props.brightness = MAX_BRIGHTNESS;
238 platform_set_drvdata(pdev, bl);
240 /* Enable reference VSYS */
241 ret = pm860x_reg_read(data->i2c, PM8606_VSYS);
244 if ((ret & PM8606_VSYS_EN) == 0) {
245 value = ret | PM8606_VSYS_EN;
246 ret = pm860x_reg_write(data->i2c, PM8606_VSYS, value);
250 /* Enable reference OSC */
251 ret = pm860x_reg_read(data->i2c, PM8606_MISC);
254 if ((ret & PM8606_MISC_OSC_EN) == 0) {
255 value = ret | PM8606_MISC_OSC_EN;
256 ret = pm860x_reg_write(data->i2c, PM8606_MISC, value);
260 /* read current backlight */
261 ret = pm860x_backlight_get_brightness(bl);
265 backlight_update_status(bl);
272 static int pm860x_backlight_remove(struct platform_device *pdev)
274 struct backlight_device *bl = platform_get_drvdata(pdev);
275 struct pm860x_backlight_data *data = bl_get_data(bl);
277 backlight_device_unregister(bl);
282 static struct platform_driver pm860x_backlight_driver = {
284 .name = "88pm860x-backlight",
285 .owner = THIS_MODULE,
287 .probe = pm860x_backlight_probe,
288 .remove = pm860x_backlight_remove,
291 static int __init pm860x_backlight_init(void)
293 return platform_driver_register(&pm860x_backlight_driver);
295 module_init(pm860x_backlight_init);
297 static void __exit pm860x_backlight_exit(void)
299 platform_driver_unregister(&pm860x_backlight_driver);
301 module_exit(pm860x_backlight_exit);
303 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
304 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
305 MODULE_LICENSE("GPL");
306 MODULE_ALIAS("platform:88pm860x-backlight");