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Subject[PATCH] backlight: add regulator support for platform_lcd driver
Date
The power source to the lcd panel or the lcd interface such as lvds
transmitters could be controlled by a regulator supply. Add support
for enabling/disabling the regulator when switching power to lcd.

Two new elements 'min_uV' and 'max_uV' in the platform data are added
to allow platform code to specifiy the desired output voltage from the
regulator.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
---
drivers/video/backlight/platform_lcd.c | 29 +++++++++++++++++++++++++++++
include/video/platform_lcd.h | 7 +++++++
2 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/drivers/video/backlight/platform_lcd.c b/drivers/video/backlight/platform_lcd.c
index 302330a..ffa8108 100644
--- a/drivers/video/backlight/platform_lcd.c
+++ b/drivers/video/backlight/platform_lcd.c
@@ -17,6 +17,8 @@
#include <linux/backlight.h>
#include <linux/lcd.h>
#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/machine.h>

#include <video/platform_lcd.h>

@@ -44,11 +46,38 @@ static int platform_lcd_get_power(struct lcd_device *lcd)
static int platform_lcd_set_power(struct lcd_device *lcd, int power)
{
struct platform_lcd *plcd = to_our_lcd(lcd);
+ struct regulator *lcd_regulator;
int lcd_power = 1;

if (power == FB_BLANK_POWERDOWN || plcd->suspended)
lcd_power = 0;

+ /*
+ * If power to lcd and/or lcd interface is controlled using a regulator,
+ * enable or disable the regulator based in the power setting.
+ */
+ lcd_regulator = regulator_get(plcd->us, "vcc_lcd");
+ if (IS_ERR(lcd_regulator)) {
+ dev_info(plcd->us, "could not get regulator\n");
+ goto set_power;
+ }
+
+ if (lcd_power) {
+ if (plcd->pdata->min_uV || plcd->pdata->max_uV)
+ if (regulator_set_voltage(lcd_regulator,
+ plcd->pdata->min_uV, plcd->pdata->max_uV))
+ dev_info(plcd->us,
+ "regulator voltage set failed\n");
+
+ if (regulator_enable(lcd_regulator))
+ dev_info(plcd->us, "failed to enable regulator\n");
+ } else {
+ regulator_disable(lcd_regulator);
+ }
+
+ regulator_put(lcd_regulator);
+
+set_power:
plcd->pdata->set_power(plcd->pdata, lcd_power);
plcd->power = power;

diff --git a/include/video/platform_lcd.h b/include/video/platform_lcd.h
index ad3bdfe..acd5d21 100644
--- a/include/video/platform_lcd.h
+++ b/include/video/platform_lcd.h
@@ -14,8 +14,15 @@
struct plat_lcd_data;
struct fb_info;

+/**
+ * struct plat_lcd_data - platform data for platform_lcd driver.
+ * @min_uV: Minimum required voltage output from the regulator.
+ * @max_uV: Maximum acceptable voltage output from the regulator.
+ */
struct plat_lcd_data {
void (*set_power)(struct plat_lcd_data *, unsigned int power);
int (*match_fb)(struct plat_lcd_data *, struct fb_info *);
+ int min_uV;
+ int max_uV;
};

--
1.6.6.rc2


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