drm/meson: dw_hdmi: add resume/suspend hooks

Add the suspend and resume hooks to:
- reset the whole HDMI glue and HDMI controller on suspend
- re-init the HDMI glue and HDMI controller on resume

The HDMI glue init is refactored to be re-used from the resume hook.

It makes usage of dw_hdmi_resume() to recover a functionnal DDC bus.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Kevin Hilman <khilman@baylibre.com>
[narmstrong: fixed typo in commit log, and rebased on drm-misc-next]
Link: https://patchwork.freedesktop.org/patch/msgid/20190827095825.21015-2-narmstrong@baylibre.com

drivers/gpu/drm/meson/meson_dw_hdmi.c

@@ -802,6 +802,47 @@ static bool meson_hdmi_connector_is_available(struct device *dev)
 	return false;
 }
 
+static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
+{
+	struct meson_drm *priv = meson_dw_hdmi->priv;
+
+	/* Enable clocks */
+	regmap_update_bits(priv->hhi, HHI_HDMI_CLK_CNTL, 0xffff, 0x100);
+
+	/* Bring HDMITX MEM output of power down */
+	regmap_update_bits(priv->hhi, HHI_MEM_PD_REG0, 0xff << 8, 0);
+
+	/* Reset HDMITX APB & TX & PHY */
+	reset_control_reset(meson_dw_hdmi->hdmitx_apb);
+	reset_control_reset(meson_dw_hdmi->hdmitx_ctrl);
+	reset_control_reset(meson_dw_hdmi->hdmitx_phy);
+
+	/* Enable APB3 fail on error */
+	if (!meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A)) {
+		writel_bits_relaxed(BIT(15), BIT(15),
+				    meson_dw_hdmi->hdmitx + HDMITX_TOP_CTRL_REG);
+		writel_bits_relaxed(BIT(15), BIT(15),
+				    meson_dw_hdmi->hdmitx + HDMITX_DWC_CTRL_REG);
+	}
+
+	/* Bring out of reset */
+	meson_dw_hdmi->data->top_write(meson_dw_hdmi,
+				       HDMITX_TOP_SW_RESET,  0);
+
+	msleep(20);
+
+	meson_dw_hdmi->data->top_write(meson_dw_hdmi,
+				       HDMITX_TOP_CLK_CNTL, 0xff);
+
+	/* Enable HDMI-TX Interrupt */
+	meson_dw_hdmi->data->top_write(meson_dw_hdmi, HDMITX_TOP_INTR_STAT_CLR,
+				       HDMITX_TOP_INTR_CORE);
+
+	meson_dw_hdmi->data->top_write(meson_dw_hdmi, HDMITX_TOP_INTR_MASKN,
+				       HDMITX_TOP_INTR_CORE);
+
+}
+
 static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 				void *data)
 {
@@ -925,40 +966,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 
 	DRM_DEBUG_DRIVER("encoder initialized\n");
 
-	/* Enable clocks */
-	regmap_update_bits(priv->hhi, HHI_HDMI_CLK_CNTL, 0xffff, 0x100);
-
-	/* Bring HDMITX MEM output of power down */
-	regmap_update_bits(priv->hhi, HHI_MEM_PD_REG0, 0xff << 8, 0);
-
-	/* Reset HDMITX APB & TX & PHY */
-	reset_control_reset(meson_dw_hdmi->hdmitx_apb);
-	reset_control_reset(meson_dw_hdmi->hdmitx_ctrl);
-	reset_control_reset(meson_dw_hdmi->hdmitx_phy);
-
-	/* Enable APB3 fail on error */
-	if (!meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A)) {
-		writel_bits_relaxed(BIT(15), BIT(15),
-				    meson_dw_hdmi->hdmitx + HDMITX_TOP_CTRL_REG);
-		writel_bits_relaxed(BIT(15), BIT(15),
-				    meson_dw_hdmi->hdmitx + HDMITX_DWC_CTRL_REG);
-	}
-
-	/* Bring out of reset */
-	meson_dw_hdmi->data->top_write(meson_dw_hdmi,
-				       HDMITX_TOP_SW_RESET,  0);
-
-	msleep(20);
-
-	meson_dw_hdmi->data->top_write(meson_dw_hdmi,
-				       HDMITX_TOP_CLK_CNTL, 0xff);
-
-	/* Enable HDMI-TX Interrupt */
-	meson_dw_hdmi->data->top_write(meson_dw_hdmi, HDMITX_TOP_INTR_STAT_CLR,
-				       HDMITX_TOP_INTR_CORE);
-
-	meson_dw_hdmi->data->top_write(meson_dw_hdmi, HDMITX_TOP_INTR_MASKN,
-				       HDMITX_TOP_INTR_CORE);
+	meson_dw_hdmi_init(meson_dw_hdmi);
 
 	/* Bridge / Connector */
 
@@ -994,6 +1002,34 @@ static const struct component_ops meson_dw_hdmi_ops = {
 	.unbind	= meson_dw_hdmi_unbind,
 };
 
+static int __maybe_unused meson_dw_hdmi_pm_suspend(struct device *dev)
+{
+	struct meson_dw_hdmi *meson_dw_hdmi = dev_get_drvdata(dev);
+
+	if (!meson_dw_hdmi)
+		return 0;
+
+	/* Reset TOP */
+	meson_dw_hdmi->data->top_write(meson_dw_hdmi,
+				       HDMITX_TOP_SW_RESET, 0);
+
+	return 0;
+}
+
+static int __maybe_unused meson_dw_hdmi_pm_resume(struct device *dev)
+{
+	struct meson_dw_hdmi *meson_dw_hdmi = dev_get_drvdata(dev);
+
+	if (!meson_dw_hdmi)
+		return 0;
+
+	meson_dw_hdmi_init(meson_dw_hdmi);
+
+	dw_hdmi_resume(meson_dw_hdmi->hdmi);
+
+	return 0;
+}
+
 static int meson_dw_hdmi_probe(struct platform_device *pdev)
 {
 	return component_add(&pdev->dev, &meson_dw_hdmi_ops);
@@ -1006,6 +1042,11 @@ static int meson_dw_hdmi_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct dev_pm_ops meson_dw_hdmi_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(meson_dw_hdmi_pm_suspend,
+				meson_dw_hdmi_pm_resume)
+};
+
 static const struct of_device_id meson_dw_hdmi_of_table[] = {
 	{ .compatible = "amlogic,meson-gxbb-dw-hdmi",
 	  .data = &meson_dw_hdmi_gx_data },
@@ -1025,6 +1066,7 @@ static struct platform_driver meson_dw_hdmi_platform_driver = {
 	.driver		= {
 		.name		= DRIVER_NAME,
 		.of_match_table	= meson_dw_hdmi_of_table,
+		.pm = &meson_dw_hdmi_pm_ops,
 	},
 };
 module_platform_driver(meson_dw_hdmi_platform_driver);