Re: [PATCH] drm/msm/dp: employ bridge mechanism for display enable and disable
From: Stephen Boyd
Date: Wed Nov 03 2021 - 16:08:53 EST
Quoting Kuogee Hsieh (2021-11-02 15:13:44)
> Current display mode_set, enable and disable functions are implemented
> as function called directly from drm encoder. This patch have display
> mode_set, enable and disable be implemented as callback function of drm
> bridge.
Why is it important? Please add those details here.
>
> Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 21 ------
> drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 8 ++
> drivers/gpu/drm/msm/dp/dp_display.c | 26 +++----
> drivers/gpu/drm/msm/dp/dp_display.h | 8 ++
> drivers/gpu/drm/msm/dp/dp_drm.c | 113 ++++++++++++++++++++++++++++
> drivers/gpu/drm/msm/msm_drv.h | 29 ++-----
> 6 files changed, 147 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> index 27d98b5..3bbd09c 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> @@ -557,6 +557,14 @@ static int _dpu_kms_initialize_displayport(struct drm_device *dev,
> encoder->base.id, rc);
> return rc;
> }
> +
> + rc = msm_dp_bridge_init(priv->dp[i], dev, encoder);
Use tabs?
> + if (rc) {
> + DPU_ERROR("failed to setup DPU bridge %d: rc:%d\n",
> + encoder->base.id, rc);
> + return rc;
> + }
> +
> }
>
> return rc;
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index e41dd40..317f963 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -569,8 +569,8 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
> return 0;
> };
>
> -static int dp_display_enable(struct dp_display_private *dp, u32 data);
> -static int dp_display_disable(struct dp_display_private *dp, u32 data);
> +static int __dp_display_enable(struct dp_display_private *dp, u32 data);
> +static int __dp_display_disable(struct dp_display_private *dp, u32 data);
>
> static int dp_connect_pending_timeout(struct dp_display_private *dp, u32 data)
> {
> @@ -855,7 +855,7 @@ static int dp_display_prepare(struct msm_dp *dp_display)
> return 0;
> }
>
> -static int dp_display_enable(struct dp_display_private *dp, u32 data)
> +static int __dp_display_enable(struct dp_display_private *dp, u32 data)
> {
> int rc = 0;
>
> @@ -898,7 +898,7 @@ static int dp_display_post_enable(struct msm_dp *dp_display)
> return 0;
> }
>
> -static int dp_display_disable(struct dp_display_private *dp, u32 data)
> +static int __dp_display_disable(struct dp_display_private *dp, u32 data)
> {
> struct msm_dp *dp_display = &dp->dp_display;
>
> @@ -1533,7 +1533,7 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
> return 0;
> }
>
> -int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
> +int dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
> {
> int rc = 0;
> struct dp_display_private *dp_display;
> @@ -1569,12 +1569,12 @@ int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
> if (state == ST_DISPLAY_OFF)
> dp_display_host_init(dp_display, true);
>
> - dp_display_enable(dp_display, 0);
> + __dp_display_enable(dp_display, 0);
>
> rc = dp_display_post_enable(dp);
> if (rc) {
> DRM_ERROR("DP display post enable failed, rc=%d\n", rc);
> - dp_display_disable(dp_display, 0);
> + __dp_display_disable(dp_display, 0);
> dp_display_unprepare(dp);
> }
>
> @@ -1590,7 +1590,7 @@ int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
> return rc;
> }
>
> -int msm_dp_display_pre_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> +int dp_display_pre_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> {
> struct dp_display_private *dp_display;
>
> @@ -1601,7 +1601,7 @@ int msm_dp_display_pre_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> return 0;
> }
>
> -int msm_dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> +int dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> {
> int rc = 0;
> u32 state;
> @@ -1614,7 +1614,7 @@ int msm_dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> /* stop sentinel checking */
> dp_del_event(dp_display, EV_DISCONNECT_PENDING_TIMEOUT);
>
> - dp_display_disable(dp_display, 0);
> + __dp_display_disable(dp_display, 0);
>
> rc = dp_display_unprepare(dp);
> if (rc)
> @@ -1632,9 +1632,9 @@ int msm_dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder)
> return rc;
> }
>
> -void msm_dp_display_mode_set(struct msm_dp *dp, struct drm_encoder *encoder,
> - struct drm_display_mode *mode,
> - struct drm_display_mode *adjusted_mode)
> +void dp_display_mode_set(struct msm_dp *dp, struct drm_encoder *encoder,
I enjoyed the msm_dp prefix before, please leave this alone. It will
make the patch much smaller too.
> + const struct drm_display_mode *mode,
> + const struct drm_display_mode *adjusted_mode)
> {
> struct dp_display_private *dp_display;
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index 76f45f9..4fb6ada 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -13,6 +13,7 @@
> struct msm_dp {
> struct drm_device *drm_dev;
> struct device *codec_dev;
> + struct drm_bridge *bridge;
> struct drm_connector *connector;
> struct drm_encoder *encoder;
> struct drm_panel *drm_panel;
> @@ -40,4 +41,11 @@ int dp_display_get_test_bpp(struct msm_dp *dp_display);
> void dp_display_signal_audio_start(struct msm_dp *dp_display);
> void dp_display_signal_audio_complete(struct msm_dp *dp_display);
>
> +int dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder);
> +int dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder);
> +int dp_display_pre_disable(struct msm_dp *dp, struct drm_encoder *encoder);
> +void dp_display_mode_set(struct msm_dp *dp, struct drm_encoder *encoder,
> + const struct drm_display_mode *mode,
> + const struct drm_display_mode *adjusted_mode);
> +
> #endif /* _DP_DISPLAY_H_ */
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
> index f33e315..812a091 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> @@ -3,14 +3,25 @@
> * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
> */
>
> +#include <linux/platform_device.h>
Why is this include necessary?
> +
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_atomic.h>
> +#include <drm/drm_bridge.h>
> #include <drm/drm_crtc.h>
>
> #include "msm_drv.h"
> #include "msm_kms.h"
> #include "dp_drm.h"
>
> +
> +struct dp_bridge {
msm_dp_bridge?
> + struct drm_bridge bridge;
> + struct msm_dp *dp_display;
> +};
> +
> +#define to_dp_display(x) container_of((x), struct dp_bridge, bridge)
> +
> struct dp_connector {
> struct drm_connector base;
> struct msm_dp *dp_display;
> @@ -162,3 +173,105 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
>
> return connector;
> }
> +
> +
> +static int dp_bridge_attach(struct drm_bridge *dp_bridge,
> + enum drm_bridge_attach_flags flags)
> +{
> + return 0;
> +}
> +
> +static bool dp_bridge_mode_fixup(struct drm_bridge *drm_bridge,
> + const struct drm_display_mode *mode,
> + struct drm_display_mode *adjusted_mode)
> +{
> + return true;
> +}
Do we need these largely empty functions?
> +
> +static void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
> + const struct drm_display_mode *mode,
> + const struct drm_display_mode *adjusted_mode)
> +{
> + struct dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> + struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> + dp_display_mode_set(dp_display, drm_bridge->encoder, mode, adjusted_mode);
> +}
> +
> +static void dp_bridge_pre_enable(struct drm_bridge *drm_bridge)
> +{
> +
> +}
Do we need this empty function?
> +
> +static void dp_bridge_enable(struct drm_bridge *drm_bridge)
> +{
> + struct dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> + struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> + dp_display_enable(dp_display, drm_bridge->encoder);
> +}
> +
> +static void dp_bridge_disable(struct drm_bridge *drm_bridge)
> +{
> + struct dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> + struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> + dp_display_pre_disable(dp_display, drm_bridge->encoder);
> +}
> +
> +static void dp_bridge_post_disable(struct drm_bridge *drm_bridge)
> +{
> + struct dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> + struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> + dp_display_disable(dp_display, drm_bridge->encoder);
> +}
> +
> +static const struct drm_bridge_funcs dp_bridge_ops = {
> + .attach = dp_bridge_attach,
> + .mode_fixup = dp_bridge_mode_fixup,
> + .pre_enable = dp_bridge_pre_enable,
> + .enable = dp_bridge_enable,
> + .disable = dp_bridge_disable,
> + .post_disable = dp_bridge_post_disable,
> + .mode_set = dp_bridge_mode_set,
> +};
> +
> +int msm_dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
> + struct drm_encoder *encoder)
> +{
> + int rc = 0;
Use tabs?
> + struct msm_drm_private *priv = NULL;
Please drop initialization of rc and priv.
> + struct dp_bridge *dp_bridge;
> + struct drm_bridge *bridge;
Use tabs?
> +
> + dp_bridge = kzalloc(sizeof(*dp_bridge), GFP_KERNEL);
> + if (!dp_bridge) {
> + rc = -ENOMEM;
> + goto error;
return -ENOMEM;
> + }
> +
> + dp_bridge->dp_display = dp_display;
> +
> + bridge = &dp_bridge->bridge;
Use tabs?
> + bridge->funcs = &dp_bridge_ops;
> + bridge->encoder = encoder;
> +
> + rc = drm_bridge_attach(encoder, bridge, NULL, 0);
We need DRM_BRIDGE_ATTACH_NO_CONNECTOR flag set as this driver makes a
connector, right?
> + if (rc) {
> + DRM_ERROR("failed to attach bridge, rc=%d\n", rc);
> + goto error_free_bridge;
> + }
> +
> + priv = dev->dev_private;
> + priv->bridges[priv->num_bridges++] = bridge;
> + dp_display->bridge = bridge;
More weird tabs.
> +
> + return 0;
> +
> +error_free_bridge:
> + kfree(bridge);
> +error:
> + return rc;
> +
> +}