video: mxsfb: Introduce regulator support

Instead of using a custom binding for retrieving the GPIO that activates the
LCD from devicetree, use a standard regulator.

This approach has the advantage to be more generic.

For example: in the case of a board that has a PMIC supplying the LCD voltage,
the current approach would not work, as it only searches for a GPIO pin.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

1 files changed, 23 insertions, 18 deletions

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index eac7c1ace7a5..1b2c26d1658c 100644
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -42,7 +42,6 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/of_device.h>
-#include <linux/of_gpio.h>
 #include <video/of_display_timing.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
@@ -50,6 +49,7 @@
 #include <linux/io.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/fb.h>
+#include <linux/regulator/consumer.h>
 #include <video/videomode.h>
 
 #define REG_SET 4
@@ -179,6 +179,7 @@ struct mxsfb_info {
         unsigned dotclk_delay;
         const struct mxsfb_devdata *devdata;
         u32 sync;
+        struct regulator *reg_lcd;
 };
 
 #define mxsfb_is_v3(host) (host->devdata->ipversion == 3)
@@ -338,9 +339,19 @@ static void mxsfb_enable_controller(struct fb_info *fb_info)
 {
         struct mxsfb_info *host = to_imxfb_host(fb_info);
         u32 reg;
+        int ret;
 
         dev_dbg(&host->pdev->dev, "%s\n", __func__);
 
+        if (host->reg_lcd) {
+                ret = regulator_enable(host->reg_lcd);
+                if (ret) {
+                        dev_err(&host->pdev->dev,
+                                "lcd regulator enable failed:   %d\n", ret);
+                        return;
+                }
+        }
+
         clk_prepare_enable(host->clk);
         clk_set_rate(host->clk, PICOS2KHZ(fb_info->var.pixclock) * 1000U);
 
@@ -362,6 +373,7 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
         struct mxsfb_info *host = to_imxfb_host(fb_info);
         unsigned loop;
         u32 reg;
+        int ret;
 
         dev_dbg(&host->pdev->dev, "%s\n", __func__);
 
@@ -385,6 +397,13 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
         clk_disable_unprepare(host->clk);
 
         host->enabled = 0;
+
+        if (host->reg_lcd) {
+                ret = regulator_disable(host->reg_lcd);
+                if (ret)
+                        dev_err(&host->pdev->dev,
+                                "lcd regulator disable failed: %d\n", ret);
+        }
 }
 
 static int mxsfb_set_par(struct fb_info *fb_info)
@@ -859,8 +878,6 @@ static int mxsfb_probe(struct platform_device *pdev)
         struct fb_info *fb_info;
         struct fb_modelist *modelist;
         struct pinctrl *pinctrl;
-        int panel_enable;
-        enum of_gpio_flags flags;
         int ret;
 
         if (of_id)
@@ -904,21 +921,9 @@ static int mxsfb_probe(struct platform_device *pdev)
                 goto fb_release;
         }
 
-        panel_enable = of_get_named_gpio_flags(pdev->dev.of_node,
-                                               "panel-enable-gpios", 0, &flags);
-        if (gpio_is_valid(panel_enable)) {
-                unsigned long f = GPIOF_OUT_INIT_HIGH;
-                if (flags == OF_GPIO_ACTIVE_LOW)
-                        f = GPIOF_OUT_INIT_LOW;
-                ret = devm_gpio_request_one(&pdev->dev, panel_enable,
-                                            f, "panel-enable");
-                if (ret) {
-                        dev_err(&pdev->dev,
-                                "failed to request gpio %d: %d\n",
-                                panel_enable, ret);
-                        goto fb_release;
-                }
-        }
+        host->reg_lcd = devm_regulator_get(&pdev->dev, "lcd");
+        if (IS_ERR(host->reg_lcd))
+                host->reg_lcd = NULL;
 
         fb_info->pseudo_palette = devm_kzalloc(&pdev->dev, sizeof(u32) * 16,
                                                GFP_KERNEL);