On 18/01/2023 23:06, Laurent Pinchart wrote:
Hi Tomi,
Thank you for the patch.
On Tue, Jan 17, 2023 at 03:51:50PM +0200, Tomi Valkeinen wrote:
From: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
Reset LVDS using the reset control as CPG reset/release is required in
H/W manual sequence.
s@H/W@the hardware@
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
Signed-off-by: LUU HOAI <hoai.luu.ub@xxxxxxxxxxx>
[tomi.valkeinen: Rewrite the patch description]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/rcar-du/Kconfig | 1 +
drivers/gpu/drm/rcar-du/rcar_lvds.c | 15 +++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
index a8f862c68b4f..151e400b996d 100644
--- a/drivers/gpu/drm/rcar-du/Kconfig
+++ b/drivers/gpu/drm/rcar-du/Kconfig
@@ -43,6 +43,7 @@ config DRM_RCAR_LVDS
select DRM_PANEL
select OF_FLATTREE
select OF_OVERLAY
+ select RESET_CONTROLLER
config DRM_RCAR_USE_MIPI_DSI
bool "R-Car DU MIPI DSI Encoder Support"
diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index 81a060c2fe3f..674b727cdaa2 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -16,6 +16,7 @@
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
@@ -60,6 +61,7 @@ struct rcar_lvds_device_info {
struct rcar_lvds {
struct device *dev;
const struct rcar_lvds_device_info *info;
+ struct reset_control *rstc;
struct drm_bridge bridge;
@@ -316,6 +318,8 @@ int rcar_lvds_pclk_enable(struct drm_bridge *bridge, unsigned long freq)
dev_dbg(lvds->dev, "enabling LVDS PLL, freq=%luHz\n", freq);
+ reset_control_deassert(lvds->rstc);
Can this fail ? Same in __rcar_lvds_atomic_enable().
Yes. Too hasty in picking a patch from the BSP =).
+
ret = clk_prepare_enable(lvds->clocks.mod);
It would be nice to switch this driver to runtime PM and move reset and
clock handling to the suspend/resume handlers. A candidate for a future
patch.
I have the runtime PM patch in my work branch, but on top. I'll pick
that into this series, before adding the reset control. Makes error
handling a bit simpler.
if (ret < 0)
Missing reset_control_assert(). Same in other error paths if applicable,
here and in __rcar_lvds_atomic_enable().
Yep.
Tomi
