drm/exynos: add pm_runtime to HDMI

Let pm_runtime handle the enabling/disabling of the device with proper
refcnt instead of rely on specific flags to track the enabled state.

Changelog v3:
- revive powered flag to keep current dpms mode

Changelog v2:
- Mofidy CONFIG_PM_SLEEP -> CONFIG_PM
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_hdmi.c

@@ -1588,8 +1588,6 @@ static void hdmi_enable(struct drm_encoder *encoder)
 	if (hdata->powered)
 		return;
 
-	hdata->powered = true;
-
 	pm_runtime_get_sync(hdata->dev);
 
 	if (regulator_bulk_enable(ARRAY_SIZE(supply), hdata->regul_bulk))
@@ -1599,10 +1597,9 @@ static void hdmi_enable(struct drm_encoder *encoder)
 	regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL,
 			PMU_HDMI_PHY_ENABLE_BIT, 1);
 
-	clk_prepare_enable(hdata->hdmi);
-	clk_prepare_enable(hdata->sclk_hdmi);
-
 	hdmi_conf_apply(hdata);
+
+	hdata->powered = true;
 }
 
 static void hdmi_disable(struct drm_encoder *encoder)
@@ -1633,9 +1630,6 @@ static void hdmi_disable(struct drm_encoder *encoder)
 
 	cancel_delayed_work(&hdata->hotplug_work);
 
-	clk_disable_unprepare(hdata->sclk_hdmi);
-	clk_disable_unprepare(hdata->hdmi);
-
 	/* reset pmu hdmiphy control bit to disable hdmiphy */
 	regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL,
 			PMU_HDMI_PHY_ENABLE_BIT, 0);
@@ -1978,12 +1972,49 @@ static int hdmi_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int exynos_hdmi_suspend(struct device *dev)
+{
+	struct hdmi_context *hdata = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(hdata->sclk_hdmi);
+	clk_disable_unprepare(hdata->hdmi);
+
+	return 0;
+}
+
+static int exynos_hdmi_resume(struct device *dev)
+{
+	struct hdmi_context *hdata = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(hdata->hdmi);
+	if (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the hdmi clk [%d]\n", ret);
+		return ret;
+	}
+	ret = clk_prepare_enable(hdata->sclk_hdmi);
+	if (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the sclk_mixer clk [%d]\n",
+			  ret);
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops exynos_hdmi_pm_ops = {
+	SET_RUNTIME_PM_OPS(exynos_hdmi_suspend, exynos_hdmi_resume, NULL)
+};
+
 struct platform_driver hdmi_driver = {
 	.probe		= hdmi_probe,
 	.remove		= hdmi_remove,
 	.driver		= {
 		.name	= "exynos-hdmi",
 		.owner	= THIS_MODULE,
+		.pm	= &exynos_hdmi_pm_ops,
 		.of_match_table = hdmi_match_types,
 	},
 };