[PATCH] backlight: l4f00242t03: full implement fb power states forthis lcd

From: Alberto Panizzo
Date: Thu Nov 11 2010 - 09:38:46 EST


This patch complete the support of fb power states managing
correctly the regulators bound to this driver.

Signed-off-by: Alberto Panizzo <maramaopercheseimorto@xxxxxxxxx>
---

This patch follow the Marek work that resides in the broken-out
queue of the -mm tree:
http://userweb.kernel.org/~akpm/mmotm/broken-out/backlight-fix-blanking-for-l4f00242t03-lcd.patch

drivers/video/backlight/l4f00242t03.c | 97 +++++++++++++++++++++++++--------
1 files changed, 75 insertions(+), 22 deletions(-)

diff --git a/drivers/video/backlight/l4f00242t03.c b/drivers/video/backlight/l4f00242t03.c
index c67801e..5d25743 100644
--- a/drivers/video/backlight/l4f00242t03.c
+++ b/drivers/video/backlight/l4f00242t03.c
@@ -25,7 +25,7 @@
struct l4f00242t03_priv {
struct spi_device *spi;
struct lcd_device *ld;
- int lcd_on:1;
+ int lcd_state;
struct regulator *io_reg;
struct regulator *core_reg;
};
@@ -67,6 +67,29 @@ static void l4f00242t03_lcd_init(struct spi_device *spi)
spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
}

+static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
+{
+ struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
+ struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
+
+ dev_dbg(&spi->dev, "Powering down LCD\n");
+
+ gpio_set_value(pdata->data_enable_gpio, 0);
+
+ if (priv->io_reg)
+ regulator_disable(priv->io_reg);
+
+ if (priv->core_reg)
+ regulator_disable(priv->core_reg);
+}
+
+static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
+{
+ struct l4f00242t03_priv *priv = lcd_get_data(ld);
+
+ return priv->lcd_state;
+}
+
static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
{
struct l4f00242t03_priv *priv = lcd_get_data(ld);
@@ -79,35 +102,52 @@ static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
const u16 disoff = 0x28;

if (power <= FB_BLANK_NORMAL) {
- if (priv->lcd_on)
- return 0;
-
- dev_dbg(&spi->dev, "turning on LCD\n");
-
- spi_write(spi, (const u8 *)&slpout, sizeof(u16));
- msleep(60);
- spi_write(spi, (const u8 *)&dison, sizeof(u16));
-
- priv->lcd_on = 1;
+ if (priv->lcd_state <= FB_BLANK_NORMAL) {
+ /* Do nothing, the LCD is running */
+ } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
+ dev_dbg(&spi->dev, "Resuming LCD\n");
+
+ spi_write(spi, (const u8 *)&slpout, sizeof(u16));
+ msleep(60);
+ spi_write(spi, (const u8 *)&dison, sizeof(u16));
+ } else {
+ /* priv->lcd_state == FB_BLANK_POWERDOWN */
+ l4f00242t03_lcd_init(spi);
+ priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
+ l4f00242t03_lcd_power_set(priv->ld, power);
+ }
+ } else if (power < FB_BLANK_POWERDOWN) {
+ if (priv->lcd_state <= FB_BLANK_NORMAL) {
+ /* Send the display in standby */
+ dev_dbg(&spi->dev, "Standby the LCD\n");
+
+ spi_write(spi, (const u8 *)&disoff, sizeof(u16));
+ msleep(60);
+ spi_write(spi, (const u8 *)&slpin, sizeof(u16));
+ } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
+ /* Do nothing, the LCD is already in standby */
+ } else {
+ /* priv->lcd_state == FB_BLANK_POWERDOWN */
+ l4f00242t03_lcd_init(spi);
+ priv->lcd_state = FB_BLANK_UNBLANK;
+ l4f00242t03_lcd_power_set(ld, power);
+ }
} else {
- if (!priv->lcd_on)
- return 0;
-
- dev_dbg(&spi->dev, "turning off LCD\n");
-
+ /* power == FB_BLANK_POWERDOWN */
+ /* Clear the screen before shutting down */
spi_write(spi, (const u8 *)&disoff, sizeof(u16));
msleep(60);
- spi_write(spi, (const u8 *)&slpin, sizeof(u16));
-
- priv->lcd_on = 0;
+ l4f00242t03_lcd_powerdown(spi);
}

+ priv->lcd_state = power;
+
return 0;
}

static struct lcd_ops l4f_ops = {
.set_power = l4f00242t03_lcd_power_set,
- .get_power = NULL,
+ .get_power = l4f00242t03_lcd_power_get,
};

static int __devinit l4f00242t03_probe(struct spi_device *spi)
@@ -187,7 +227,8 @@ static int __devinit l4f00242t03_probe(struct spi_device *spi)
/* Init the LCD */
l4f00242t03_reset(pdata->reset_gpio);
l4f00242t03_lcd_init(spi);
- l4f00242t03_lcd_power_set(priv->ld, 1);
+ priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
+ l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);

dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");

@@ -214,9 +255,11 @@ static int __devexit l4f00242t03_remove(struct spi_device *spi)
struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;

- l4f00242t03_lcd_power_set(priv->ld, 0);
+ l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
lcd_device_unregister(priv->ld);

+ dev_set_drvdata(&spi->dev, NULL);
+
gpio_free(pdata->data_enable_gpio);
gpio_free(pdata->reset_gpio);

@@ -230,6 +273,15 @@ static int __devexit l4f00242t03_remove(struct spi_device *spi)
return 0;
}

+static void l4f00242t03_shutdown(struct spi_device *spi)
+{
+ struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
+
+ if (priv)
+ l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
+
+}
+
static struct spi_driver l4f00242t03_driver = {
.driver = {
.name = "l4f00242t03",
@@ -237,6 +289,7 @@ static struct spi_driver l4f00242t03_driver = {
},
.probe = l4f00242t03_probe,
.remove = __devexit_p(l4f00242t03_remove),
+ .shutdown = l4f00242t03_shutdown,
};

static __init int l4f00242t03_init(void)
--
1.6.3.3



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