drm/exynos: Enable DP clock to fix display on Exynos5250 and other

After adding display power domain for Exynos5250 in commit
2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250") the
display on Chromebook Snow and others stopped working after boot.

The reason for this suggested Andrzej Hajda: the DP clock was disabled.
This clock is required by Display Port and is enabled by bootloader.
However when FIMD driver probing was deferred, the display power domain
was turned off. This effectively reset the value of DP clock enable
register.

When exynos-dp is later probed, the clock is not enabled and display is
not properly configured:

exynos-dp 145b0000.dp-controller: Timeout of video streamclk ok
exynos-dp 145b0000.dp-controller: unable to config video

Fixes: 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reported-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/drm/exynos/exynos_dp_core.c
index bf17a60..1dbfba5 100644 (file)
--- a/drivers/gpu/drm/exynos/exynos_dp_core.c
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.c
@@ -32,10 +32,16 @@
 #include <drm/bridge/ptn3460.h>
 
 #include "exynos_dp_core.h"
+#include "exynos_drm_fimd.h"
 
 #define ctx_from_connector(c)  container_of(c, struct exynos_dp_device, \
                                        connector)
 
+static inline struct exynos_drm_crtc *dp_to_crtc(struct exynos_dp_device *dp)
+{
+       return to_exynos_crtc(dp->encoder->crtc);
+}
+
 static inline struct exynos_dp_device *
 display_to_dp(struct exynos_drm_display *d)
 {
@@ -1070,6 +1076,8 @@ static void exynos_dp_poweron(struct exynos_dp_device *dp)
                }
        }
 
+       fimd_dp_clock_enable(dp_to_crtc(dp), true);
+
        clk_prepare_enable(dp->clock);
        exynos_dp_phy_init(dp);
        exynos_dp_init_dp(dp);
@@ -1094,6 +1102,8 @@ static void exynos_dp_poweroff(struct exynos_dp_device *dp)
        exynos_dp_phy_exit(dp);
        clk_disable_unprepare(dp->clock);
 
+       fimd_dp_clock_enable(dp_to_crtc(dp), false);
+
        if (dp->panel) {
                if (drm_panel_unprepare(dp->panel))
                        DRM_ERROR("failed to turnoff the panel\n");

diff --cc drivers/gpu/drm/exynos/exynos_drm_fimd.c
Simple merge

diff --cc drivers/gpu/drm/exynos/exynos_drm_fimd.h
Simple merge

diff --cc include/video/samsung_fimd.h
Simple merge