[PATCH RFC/DO NOT MERGE 08/12] drm/msm/hdmi: Add support for PM OPP table

[Krzysztof Kozlowski]

Allow scaling the domain rails with PM OPP, which uses the pixclock
("extp").  This allows proper votes depending on requested HDMI pixel
rate.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at oss.qualcomm.com>
---
 drivers/gpu/drm/msm/hdmi/hdmi.c        |  8 ++++++++
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 10 +++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
index 474006084633..c46f30063f14 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
@@ -368,6 +368,14 @@ static int msm_hdmi_dev_probe(struct platform_device *pdev)
 		goto err_put_bridge;
 	}
 
+	ret = devm_pm_opp_set_clkname(dev, "extp");
+	if (ret)
+		return ret;
+
+	ret = devm_pm_opp_of_add_table(dev);
+	if (ret && ret != -ENODEV)
+		return dev_err_probe(dev, ret, "invalid OPP table in device tree\n");
+
 	if (!hdmi->hpd_gpiod)
 		DBG("failed to get HPD gpio");
 
diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
index d0e3b27644fe..621083a97b37 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/delay.h>
+#include <linux/pm_opp.h>
 #include <drm/drm_bridge_connector.h>
 #include <drm/drm_edid.h>
 #include <drm/display/drm_hdmi_helper.h>
@@ -30,9 +31,10 @@ static void msm_hdmi_clk_prepare(struct drm_bridge *bridge)
 
 	if (hdmi->extp_clk) {
 		DBG("pixclock: %lu", hdmi->pixclock);
-		ret = clk_set_rate(hdmi->extp_clk, hdmi->pixclock);
+
+		ret = dev_pm_opp_set_rate(&hdmi->pdev->dev, hdmi->pixclock);
 		if (ret)
-			DRM_DEV_ERROR(dev->dev, "failed to set extp clk rate: %d\n", ret);
+			DRM_DEV_ERROR(dev->dev, "failed to set OPP rate: %d\n", ret);
 
 		ret = clk_prepare_enable(hdmi->extp_clk);
 		if (ret)
@@ -58,8 +60,10 @@ static void msm_hdmi_clk_unprepare(struct drm_bridge *bridge)
 	struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
 	struct hdmi *hdmi = hdmi_bridge->hdmi;
 
-	if (hdmi->extp_clk)
+	if (hdmi->extp_clk) {
 		clk_disable_unprepare(hdmi->extp_clk);
+		dev_pm_opp_set_rate(&hdmi->pdev->dev, 0);
+	}
 }
 
 #define AVI_IFRAME_LINE_NUMBER 1

-- 
2.53.0