drm/exynos: use regmap interface to set hdmiphy control bit in pmu

Exynos drm hdmi driver used to get dummy hdmiphy clock to
control the PMU bit for hdmiphy. This bit needs to be set
before setting any resolution to hdmi hardware. This was
handled using dummy hdmiphy clock which is removed here.

PMU is already defined as system controller for exynos
SoCs. Hdmi driver is modified to control the phy enable bit
inside PMU using regmap interfaces.

Devicetree binding document for hdmi is also updated.
Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

Documentation/devicetree/bindings/video/exynos_hdmi.txt

@@ -28,6 +28,7 @@ Required properties:
 	"hdmi", "sclk_hdmi", "sclk_pixel", "sclk_hdmiphy" and "mout_hdmi".
 - ddc: phandle to the hdmi ddc node
 - phy: phandle to the hdmi phy node
+- samsung,syscon-phandle: phandle for system controller node for PMU.
 
 Example:
 
@@ -38,4 +39,5 @@ Example:
 		hpd-gpio = <&gpx3 7 1>;
 		ddc = <&hdmi_ddc_node>;
 		phy = <&hdmi_phy_node>;
+		samsung,syscon-phandle = <&pmu_system_controller>;
 	};

drivers/gpu/drm/exynos/exynos_hdmi.c

@@ -38,6 +38,8 @@
 #include <linux/of_gpio.h>
 #include <linux/hdmi.h>
 #include <linux/component.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #include <drm/exynos_drm.h>
 
@@ -81,7 +83,6 @@ struct hdmi_resources {
 	struct clk			*sclk_hdmi;
 	struct clk			*sclk_pixel;
 	struct clk			*sclk_hdmiphy;
-	struct clk			*hdmiphy;
 	struct clk			*mout_hdmi;
 	struct regulator_bulk_data	*regul_bulk;
 	int				regul_count;
@@ -208,6 +209,7 @@ struct hdmi_context {
 	const struct hdmiphy_config		*phy_confs;
 	unsigned int			phy_conf_count;
 
+	struct regmap			*pmureg;
 	enum hdmi_type			type;
 };
 
@@ -2013,7 +2015,10 @@ static void hdmi_poweron(struct exynos_drm_display *display)
 	if (regulator_bulk_enable(res->regul_count, res->regul_bulk))
 		DRM_DEBUG_KMS("failed to enable regulator bulk\n");
 
-	clk_prepare_enable(res->hdmiphy);
+	/* set pmu hdmiphy control bit to enable hdmiphy */
+	regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL,
+			PMU_HDMI_PHY_ENABLE_BIT, 1);
+
 	clk_prepare_enable(res->hdmi);
 	clk_prepare_enable(res->sclk_hdmi);
 
@@ -2040,7 +2045,11 @@ static void hdmi_poweroff(struct exynos_drm_display *display)
 
 	clk_disable_unprepare(res->sclk_hdmi);
 	clk_disable_unprepare(res->hdmi);
-	clk_disable_unprepare(res->hdmiphy);
+
+	/* reset pmu hdmiphy control bit to disable hdmiphy */
+	regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL,
+			PMU_HDMI_PHY_ENABLE_BIT, 0);
+
 	regulator_bulk_disable(res->regul_count, res->regul_bulk);
 
 	pm_runtime_put_sync(hdata->dev);
@@ -2143,11 +2152,6 @@ static int hdmi_resources_init(struct hdmi_context *hdata)
 		DRM_ERROR("failed to get clock 'sclk_hdmiphy'\n");
 		goto fail;
 	}
-	res->hdmiphy = devm_clk_get(dev, "hdmiphy");
-	if (IS_ERR(res->hdmiphy)) {
-		DRM_ERROR("failed to get clock 'hdmiphy'\n");
-		goto fail;
-	}
 	res->mout_hdmi = devm_clk_get(dev, "mout_hdmi");
 	if (IS_ERR(res->mout_hdmi)) {
 		DRM_ERROR("failed to get clock 'mout_hdmi'\n");
@@ -2383,6 +2387,13 @@ static int hdmi_probe(struct platform_device *pdev)
 		goto err_hdmiphy;
 	}
 
+	hdata->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
+			"samsung,syscon-phandle");
+	if (IS_ERR(hdata->pmureg)) {
+		DRM_ERROR("syscon regmap lookup failed.\n");
+		goto err_hdmiphy;
+	}
+
 	pm_runtime_enable(dev);
 	hdmi_display.ctx = hdata;
 

drivers/gpu/drm/exynos/regs-hdmi.h

@@ -585,4 +585,8 @@
 #define HDMI_PHY_DISABLE_MODE_SET	0x80
 #define HDMI_PHY_ENABLE_MODE_SET	0x00
 
+/* PMU Registers for PHY */
+#define PMU_HDMI_PHY_CONTROL		0x700
+#define PMU_HDMI_PHY_ENABLE_BIT		BIT(0)
+
 #endif /* SAMSUNG_REGS_HDMI_H */