[PATCHv12][ 1/8] video: imxfb: Introduce regulator support.

[denis@eukrea.com (Denis Carikli)]

This commit is based on the following commit by Fabio Estevam:
  4344429 video: mxsfb: Introduce regulator support

Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: linux-arm-kernel at lists.infradead.org
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-fbdev at vger.kernel.org
Cc: Eric B?nard <eric@eukrea.com>
Signed-off-by: Denis Carikli <denis@eukrea.com>
---
ChangeLog v9->v10:
- Added a return 0; at the end of imxfb_disable_controller.

ChangeLog v8->v9:
- return an error if regulator_{enable,disable} fails in
  imxfb_{enable,disable}_controller, and use it.
---
 drivers/video/imxfb.c |   55 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 43 insertions(+), 12 deletions(-)

diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c
index 38733ac..a2fe8bd 100644
--- a/drivers/video/imxfb.c
+++ b/drivers/video/imxfb.c
@@ -28,6 +28,7 @@
 #include <linux/cpufreq.h>
 #include <linux/clk.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/math64.h>
@@ -145,6 +146,7 @@ struct imxfb_info {
 	struct clk		*clk_ipg;
 	struct clk		*clk_ahb;
 	struct clk		*clk_per;
+	struct regulator	*reg_lcd;
 	enum imxfb_type		devtype;
 	bool			enabled;
 
@@ -561,14 +563,25 @@ static void imxfb_exit_backlight(struct imxfb_info *fbi)
 }
 #endif
 
-static void imxfb_enable_controller(struct imxfb_info *fbi)
+static int imxfb_enable_controller(struct imxfb_info *fbi)
 {
+	int ret;
 
 	if (fbi->enabled)
-		return;
+		return 0;
 
 	pr_debug("Enabling LCD controller\n");
 
+	if (fbi->reg_lcd) {
+		ret = regulator_enable(fbi->reg_lcd);
+		if (ret) {
+			dev_err(&fbi->pdev->dev,
+				"lcd regulator enable failed with error: %d\n",
+				ret);
+			return ret;
+		}
+	}
+
 	writel(fbi->screen_dma, fbi->regs + LCDC_SSA);
 
 	/* panning offset 0 (0 pixel offset)        */
@@ -593,12 +606,16 @@ static void imxfb_enable_controller(struct imxfb_info *fbi)
 		fbi->backlight_power(1);
 	if (fbi->lcd_power)
 		fbi->lcd_power(1);
+
+	return 0;
 }
 
-static void imxfb_disable_controller(struct imxfb_info *fbi)
+static int imxfb_disable_controller(struct imxfb_info *fbi)
 {
+	int ret;
+
 	if (!fbi->enabled)
-		return;
+		return 0;
 
 	pr_debug("Disabling LCD controller\n");
 
@@ -613,6 +630,17 @@ static void imxfb_disable_controller(struct imxfb_info *fbi)
 	fbi->enabled = false;
 
 	writel(0, fbi->regs + LCDC_RMCR);
+
+	if (fbi->reg_lcd) {
+		ret = regulator_disable(fbi->reg_lcd);
+		if (ret)
+			dev_err(&fbi->pdev->dev,
+				"lcd regulator disable failed with error: %d\n",
+				ret);
+			return ret;
+	}
+
+	return 0;
 }
 
 static int imxfb_blank(int blank, struct fb_info *info)
@@ -626,13 +654,12 @@ static int imxfb_blank(int blank, struct fb_info *info)
 	case FB_BLANK_VSYNC_SUSPEND:
 	case FB_BLANK_HSYNC_SUSPEND:
 	case FB_BLANK_NORMAL:
-		imxfb_disable_controller(fbi);
-		break;
+		return imxfb_disable_controller(fbi);
 
 	case FB_BLANK_UNBLANK:
-		imxfb_enable_controller(fbi);
-		break;
+		return imxfb_enable_controller(fbi);
 	}
+
 	return 0;
 }
 
@@ -734,8 +761,7 @@ static int imxfb_suspend(struct platform_device *dev, pm_message_t state)
 
 	pr_debug("%s\n", __func__);
 
-	imxfb_disable_controller(fbi);
-	return 0;
+	return imxfb_disable_controller(fbi);
 }
 
 static int imxfb_resume(struct platform_device *dev)
@@ -745,8 +771,7 @@ static int imxfb_resume(struct platform_device *dev)
 
 	pr_debug("%s\n", __func__);
 
-	imxfb_enable_controller(fbi);
-	return 0;
+	return imxfb_enable_controller(fbi);
 }
 #else
 #define imxfb_suspend	NULL
@@ -1020,6 +1045,12 @@ static int imxfb_probe(struct platform_device *pdev)
 		goto failed_register;
 	}
 
+	fbi->reg_lcd = devm_regulator_get(&pdev->dev, "lcd");
+	if (IS_ERR(fbi->reg_lcd)) {
+		dev_info(&pdev->dev, "No lcd regulator used.\n");
+		fbi->reg_lcd = NULL;
+	}
+
 	imxfb_enable_controller(fbi);
 	fbi->pdev = pdev;
 #ifdef PWMR_BACKLIGHT_AVAILABLE
-- 
1.7.9.5