diff mbox series

[v2,1/3] vop2: Add clock resets support

Message ID 20240522185924.461742-2-detlev.casanova@collabora.com (mailing list archive)
State New
Headers show
Series drm: rockchip: vop2: Add VP clock resets support | expand

Commit Message

Detlev Casanova May 22, 2024, 6:57 p.m. UTC
At the end of initialization, each VP clock needs to be reset before
they can be used.

Failing to do so can put the VOP in an undefined state where the
generated HDMI signal is either lost or not matching the selected mode.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 30 ++++++++++++++++++++
 1 file changed, 30 insertions(+)

Comments

Andy Yan May 24, 2024, 3:09 a.m. UTC | #1
Hi Detlev,


At 2024-05-23 02:57:48, "Detlev Casanova" <detlev.casanova@collabora.com> wrote:
>At the end of initialization, each VP clock needs to be reset before
>they can be used.
>
>Failing to do so can put the VOP in an undefined state where the
>generated HDMI signal is either lost or not matching the selected mode.

Would you please provide a detailed description of your test case?


>
>Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
>---
> drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 30 ++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
>diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>index fdd768bbd487c..e81a67161d29a 100644
>--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>@@ -17,6 +17,7 @@
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <linux/regmap.h>
>+#include <linux/reset.h>
> #include <linux/swab.h>
> 
> #include <drm/drm.h>
>@@ -157,6 +158,7 @@ struct vop2_win {
> struct vop2_video_port {
> 	struct drm_crtc crtc;
> 	struct vop2 *vop2;
>+	struct reset_control *dclk_rst;
> 	struct clk *dclk;
> 	unsigned int id;
> 	const struct vop2_video_port_data *data;
>@@ -1915,6 +1917,26 @@ static int us_to_vertical_line(struct drm_display_mode *mode, int us)
> 	return us * mode->clock / mode->htotal / 1000;
> }
> 
>+static int vop2_clk_reset(struct vop2_video_port *vp)
>+{
>+	struct reset_control *rstc = vp->dclk_rst;
>+	struct vop2 *vop2 = vp->vop2;
>+	int ret;
>+
>+	if (!rstc)
>+		return 0;


In fact, this check is not necessary here.  The following reset control api will check for NULL pointer。

>+
>+	ret = reset_control_assert(rstc);
>+	if (ret < 0)
>+		drm_warn(vop2->drm, "failed to assert reset\n");
>+	udelay(10);
>+	ret = reset_control_deassert(rstc);
>+	if (ret < 0)
>+		drm_warn(vop2->drm, "failed to deassert reset\n");
>+
>+	return ret;
>+}
>+
> static void vop2_crtc_atomic_enable(struct drm_crtc *crtc,
> 				    struct drm_atomic_state *state)
> {
>@@ -2055,6 +2077,8 @@ static void vop2_crtc_atomic_enable(struct drm_crtc *crtc,
> 
> 	vop2_vp_write(vp, RK3568_VP_DSP_CTRL, dsp_ctrl);
> 
>+	vop2_clk_reset(vp);
>+
> 	drm_crtc_vblank_on(crtc);
> 
> 	vop2_unlock(vop2);
>@@ -2706,6 +2730,12 @@ static int vop2_create_crtcs(struct vop2 *vop2)
> 		vp->data = vp_data;
> 
> 		snprintf(dclk_name, sizeof(dclk_name), "dclk_vp%d", vp->id);
>+		vp->dclk_rst = devm_reset_control_get_optional(vop2->dev, dclk_name);
>+		if (IS_ERR(vp->dclk_rst)) {
>+		        drm_err(vop2->drm, "failed to get %s reset\n", dclk_name);
>+		        return PTR_ERR(vp->dclk_rst);
>+		}
>+
> 		vp->dclk = devm_clk_get(vop2->dev, dclk_name);
> 		if (IS_ERR(vp->dclk)) {
> 			drm_err(vop2->drm, "failed to get %s\n", dclk_name);
>-- 
>2.44.1
>
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox series

Patch

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
index fdd768bbd487c..e81a67161d29a 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
@@ -17,6 +17,7 @@ 
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
+#include <linux/reset.h>
 #include <linux/swab.h>
 
 #include <drm/drm.h>
@@ -157,6 +158,7 @@  struct vop2_win {
 struct vop2_video_port {
 	struct drm_crtc crtc;
 	struct vop2 *vop2;
+	struct reset_control *dclk_rst;
 	struct clk *dclk;
 	unsigned int id;
 	const struct vop2_video_port_data *data;
@@ -1915,6 +1917,26 @@  static int us_to_vertical_line(struct drm_display_mode *mode, int us)
 	return us * mode->clock / mode->htotal / 1000;
 }
 
+static int vop2_clk_reset(struct vop2_video_port *vp)
+{
+	struct reset_control *rstc = vp->dclk_rst;
+	struct vop2 *vop2 = vp->vop2;
+	int ret;
+
+	if (!rstc)
+		return 0;
+
+	ret = reset_control_assert(rstc);
+	if (ret < 0)
+		drm_warn(vop2->drm, "failed to assert reset\n");
+	udelay(10);
+	ret = reset_control_deassert(rstc);
+	if (ret < 0)
+		drm_warn(vop2->drm, "failed to deassert reset\n");
+
+	return ret;
+}
+
 static void vop2_crtc_atomic_enable(struct drm_crtc *crtc,
 				    struct drm_atomic_state *state)
 {
@@ -2055,6 +2077,8 @@  static void vop2_crtc_atomic_enable(struct drm_crtc *crtc,
 
 	vop2_vp_write(vp, RK3568_VP_DSP_CTRL, dsp_ctrl);
 
+	vop2_clk_reset(vp);
+
 	drm_crtc_vblank_on(crtc);
 
 	vop2_unlock(vop2);
@@ -2706,6 +2730,12 @@  static int vop2_create_crtcs(struct vop2 *vop2)
 		vp->data = vp_data;
 
 		snprintf(dclk_name, sizeof(dclk_name), "dclk_vp%d", vp->id);
+		vp->dclk_rst = devm_reset_control_get_optional(vop2->dev, dclk_name);
+		if (IS_ERR(vp->dclk_rst)) {
+		        drm_err(vop2->drm, "failed to get %s reset\n", dclk_name);
+		        return PTR_ERR(vp->dclk_rst);
+		}
+
 		vp->dclk = devm_clk_get(vop2->dev, dclk_name);
 		if (IS_ERR(vp->dclk)) {
 			drm_err(vop2->drm, "failed to get %s\n", dclk_name);