drm/exynos: hdmi: make 'hdmi-en' regulator optional and keep it enabled

HDMI_EN regulator is additional regulator for providing voltage source
for DCC lines available on HDMI connector. When there is no power
provided for DDC epprom, some TV-sets do not pulls up HPD (hot plug
detect) line, what causes HDMI block to stay turned off. This patch
enables HDMI_EN regulator (if available) on driver probe and keep it
enabled all the time to let TV-set correctly signal HPD event.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 738f2d7e16a1..9ec787f8529a 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -84,6 +84,7 @@ struct hdmi_resources {
         struct clk                      *sclk_hdmiphy;
         struct clk                      *mout_hdmi;
         struct regulator_bulk_data      *regul_bulk;
+        struct regulator                *reg_hdmi_en;
         int                             regul_count;
 };
 
@@ -2167,7 +2168,6 @@ static int hdmi_resources_init(struct hdmi_context *hdata)
         struct device *dev = hdata->dev;
         struct hdmi_resources *res = &hdata->res;
         static char *supply[] = {
-                "hdmi-en",
                 "vdd",
                 "vdd_osc",
                 "vdd_pll",
@@ -2227,6 +2227,20 @@ static int hdmi_resources_init(struct hdmi_context *hdata)
         }
         res->regul_count = ARRAY_SIZE(supply);
 
+        res->reg_hdmi_en = devm_regulator_get(dev, "hdmi-en");
+        if (IS_ERR(res->reg_hdmi_en) && PTR_ERR(res->reg_hdmi_en) != -ENOENT) {
+                DRM_ERROR("failed to get hdmi-en regulator\n");
+                return PTR_ERR(res->reg_hdmi_en);
+        }
+        if (!IS_ERR(res->reg_hdmi_en)) {
+                ret = regulator_enable(res->reg_hdmi_en);
+                if (ret) {
+                        DRM_ERROR("failed to enable hdmi-en regulator\n");
+                        return ret;
+                }
+        } else
+                res->reg_hdmi_en = NULL;
+
         return ret;
 fail:
         DRM_ERROR("HDMI resource init - failed\n");
@@ -2493,6 +2507,9 @@ static int hdmi_remove(struct platform_device *pdev)
 
         cancel_delayed_work_sync(&hdata->hotplug_work);
 
+        if (hdata->res.reg_hdmi_en)
+                regulator_disable(hdata->res.reg_hdmi_en);
+
         put_device(&hdata->hdmiphy_port->dev);
         put_device(&hdata->ddc_adpt->dev);