drivers/video/backlight/l4f00242t03.c: full implement fb power states for this lcd

Complete the support of fb power states managing correctly the regulators
bound to this driver.

Signed-off-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 75 insertions, 22 deletions

diff --git a/drivers/video/backlight/l4f00242t03.c b/drivers/video/backlight/l4f00242t03.c
index 6d9ba0e2b0c5..5d25743bf8e2 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;
-        unsigned 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)