Re: [PATCH v3 5/5] drm/msm: allow compile time selection of driver components

[Abhinav Kumar <quic_abhinavk@quicinc.com>]

On 3/3/2022 7:21 PM, Dmitry Baryshkov wrote:
> MSM DRM driver already allows one to compile out the DP or DSI support.
> Add support for disabling other features like MDP4/MDP5/DPU drivers or
> direct HDMI output support.
> 
> Suggested-by: Stephen Boyd <swboyd@chromium.org>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>   drivers/gpu/drm/msm/Kconfig    | 50 ++++++++++++++++++++++++++++++++--
>   drivers/gpu/drm/msm/Makefile   | 18 ++++++++++--
>   drivers/gpu/drm/msm/msm_drv.h  | 33 ++++++++++++++++++++++
>   drivers/gpu/drm/msm/msm_mdss.c | 13 +++++++--
>   4 files changed, 106 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
> index 9b019598e042..3735fd41eb3b 100644
> --- a/drivers/gpu/drm/msm/Kconfig
> +++ b/drivers/gpu/drm/msm/Kconfig
> @@ -46,12 +46,39 @@ config DRM_MSM_GPU_SUDO
>   	  Only use this if you are a driver developer.  This should *not*
>   	  be enabled for production kernels.  If unsure, say N.
>   
> -config DRM_MSM_HDMI_HDCP
> -	bool "Enable HDMI HDCP support in MSM DRM driver"
> +config DRM_MSM_MDSS
> +	bool
> +	depends on DRM_MSM
> +	default n
shouldnt DRM_MSM_MDSS be defaulted to y?

Another question is the compilation validation of the combinations of these.

So we need to try:

1) DRM_MSM_MDSS + DRM_MSM_MDP4
2) DRM_MSM_MDSS + DRM_MSM_MDP5
3) DRM_MSM_MDSS + DRM_MSM_DPU

Earlier since all of them were compiled together any inter-dependencies 
will not show up. Now since we are separating it out, just wanted to 
make sure each of the combos compile?

> +
> +config DRM_MSM_MDP4
> +	bool "Enable MDP4 support in MSM DRM driver"
>   	depends on DRM_MSM
>   	default y
>   	help
> -	  Choose this option to enable HDCP state machine
> +	  Compile in support for the Mobile Display Processor v4 (MDP4) in
> +	  the MSM DRM driver. It is the older display controller found in
> +	  devices using APQ8064/MSM8960/MSM8x60 platforms.
> +
> +config DRM_MSM_MDP5
> +	bool "Enable MDP5 support in MSM DRM driver"
> +	depends on DRM_MSM
> +	select DRM_MSM_MDSS
> +	default y
> +	help
> +	  Compile in support for the Mobile Display Processor v5 (MDP4) in
> +	  the MSM DRM driver. It is the display controller found in devices
> +	  using e.g. APQ8016/MSM8916/APQ8096/MSM8996/MSM8974/SDM6x0 platforms.
> +
> +config DRM_MSM_DPU
> +	bool "Enable DPU support in MSM DRM driver"
> +	depends on DRM_MSM
> +	select DRM_MSM_MDSS
> +	default y
> +	help
> +	  Compile in support for the Display Processing Unit in
> +	  the MSM DRM driver. It is the display controller found in devices
> +	  using e.g. SDM845 and newer platforms.
>   
>   config DRM_MSM_DP
>   	bool "Enable DisplayPort support in MSM DRM driver"
> @@ -116,3 +143,20 @@ config DRM_MSM_DSI_7NM_PHY
>   	help
>   	  Choose this option if DSI PHY on SM8150/SM8250/SC7280 is used on
>   	  the platform.
> +
> +config DRM_MSM_HDMI
> +	bool "Enable HDMI support in MSM DRM driver"
> +	depends on DRM_MSM
> +	default y
> +	help
> +	  Compile in support for the HDMI output MSM DRM driver. It can
> +	  be a primary or a secondary display on device. Note that this is used
> +	  only for the direct HDMI output. If the device outputs HDMI data
> +	  throught some kind of DSI-to-HDMI bridge, this option can be disabled.
> +
> +config DRM_MSM_HDMI_HDCP
> +	bool "Enable HDMI HDCP support in MSM DRM driver"
> +	depends on DRM_MSM && DRM_MSM_HDMI
> +	default y
> +	help
> +	  Choose this option to enable HDCP state machine
> diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
> index e76927b42033..5fe9c20ab9ee 100644
> --- a/drivers/gpu/drm/msm/Makefile
> +++ b/drivers/gpu/drm/msm/Makefile
> @@ -16,6 +16,8 @@ msm-y := \
>   	adreno/a6xx_gpu.o \
>   	adreno/a6xx_gmu.o \
>   	adreno/a6xx_hfi.o \
> +
> +msm-$(CONFIG_DRM_MSM_HDMI) += \
>   	hdmi/hdmi.o \
>   	hdmi/hdmi_audio.o \
>   	hdmi/hdmi_bridge.o \
> @@ -27,8 +29,8 @@ msm-y := \
>   	hdmi/hdmi_phy_8x60.o \
>   	hdmi/hdmi_phy_8x74.o \
>   	hdmi/hdmi_pll_8960.o \
> -	disp/mdp_format.o \
> -	disp/mdp_kms.o \
> +
> +msm-$(CONFIG_DRM_MSM_MDP4) += \
>   	disp/mdp4/mdp4_crtc.o \
>   	disp/mdp4/mdp4_dtv_encoder.o \
>   	disp/mdp4/mdp4_lcdc_encoder.o \
> @@ -37,6 +39,8 @@ msm-y := \
>   	disp/mdp4/mdp4_irq.o \
>   	disp/mdp4/mdp4_kms.o \
>   	disp/mdp4/mdp4_plane.o \
> +
> +msm-$(CONFIG_DRM_MSM_MDP5) += \
>   	disp/mdp5/mdp5_cfg.o \
>   	disp/mdp5/mdp5_ctl.o \
>   	disp/mdp5/mdp5_crtc.o \
> @@ -47,6 +51,8 @@ msm-y := \
>   	disp/mdp5/mdp5_mixer.o \
>   	disp/mdp5/mdp5_plane.o \
>   	disp/mdp5/mdp5_smp.o \
> +
> +msm-$(CONFIG_DRM_MSM_DPU) += \
>   	disp/dpu1/dpu_core_perf.o \
>   	disp/dpu1/dpu_crtc.o \
>   	disp/dpu1/dpu_encoder.o \
> @@ -69,6 +75,13 @@ msm-y := \
>   	disp/dpu1/dpu_plane.o \
>   	disp/dpu1/dpu_rm.o \
>   	disp/dpu1/dpu_vbif.o \
> +
> +msm-$(CONFIG_DRM_MSM_MDSS) += \
> +	msm_mdss.o \
> +
> +msm-y += \
> +	disp/mdp_format.o \
> +	disp/mdp_kms.o \
>   	disp/msm_disp_snapshot.o \
>   	disp/msm_disp_snapshot_util.o \
>   	msm_atomic.o \
> @@ -86,7 +99,6 @@ msm-y := \
>   	msm_gpu_devfreq.o \
>   	msm_io_utils.o \
>   	msm_iommu.o \
> -	msm_mdss.o \
>   	msm_perf.o \
>   	msm_rd.o \
>   	msm_ringbuffer.o \
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index c1aaadfbea34..6bad7e7b479d 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -314,10 +314,20 @@ struct drm_fb_helper *msm_fbdev_init(struct drm_device *dev);
>   void msm_fbdev_free(struct drm_device *dev);
>   
>   struct hdmi;
> +#ifdef CONFIG_DRM_MSM_HDMI
>   int msm_hdmi_modeset_init(struct hdmi *hdmi, struct drm_device *dev,
>   		struct drm_encoder *encoder);
>   void __init msm_hdmi_register(void);
>   void __exit msm_hdmi_unregister(void);
> +#else
> +static inline int msm_hdmi_modeset_init(struct hdmi *hdmi, struct drm_device *dev,
> +		struct drm_encoder *encoder)
> +{
> +	return -EINVAL;
> +}
> +static inline void __init msm_hdmi_register(void) {}
> +static inline void __exit msm_hdmi_unregister(void) {}
> +#endif
>   
>   struct msm_dsi;
>   #ifdef CONFIG_DRM_MSM_DSI
> @@ -432,14 +442,37 @@ static inline void msm_dp_debugfs_init(struct msm_dp *dp_display,
>   
>   #endif
>   
> +#ifdef CONFIG_DRM_MSM_MDP4
>   void msm_mdp4_register(void);
>   void msm_mdp4_unregister(void);
> +#else
> +static inline void msm_mdp4_register(void) {}
> +static inline void msm_mdp4_unregister(void) {}
> +#endif
> +
> +#ifdef CONFIG_DRM_MSM_MDP5
>   void msm_mdp_register(void);
>   void msm_mdp_unregister(void);
> +#else
> +static inline void msm_mdp_register(void) {}
> +static inline void msm_mdp_unregister(void) {}
> +#endif
> +
> +#ifdef CONFIG_DRM_MSM_DPU
>   void msm_dpu_register(void);
>   void msm_dpu_unregister(void);
> +#else
> +static inline void msm_dpu_register(void) {}
> +static inline void msm_dpu_unregister(void) {}
> +#endif
> +
> +#ifdef CONFIG_DRM_MSM_MDSS
>   void msm_mdss_register(void);
>   void msm_mdss_unregister(void);
> +#else
> +static inline void msm_mdss_register(void) {}
> +static inline void msm_mdss_unregister(void) {}
> +#endif
>   
>   #ifdef CONFIG_DEBUG_FS
>   void msm_framebuffer_describe(struct drm_framebuffer *fb, struct seq_file *m);
> diff --git a/drivers/gpu/drm/msm/msm_mdss.c b/drivers/gpu/drm/msm/msm_mdss.c
> index 4d25d8955301..66714b356762 100644
> --- a/drivers/gpu/drm/msm/msm_mdss.c
> +++ b/drivers/gpu/drm/msm/msm_mdss.c
> @@ -303,8 +303,17 @@ static const struct dev_pm_ops mdss_pm_ops = {
>   
>   static int find_mdp_node(struct device *dev, void *data)
>   {
> -	return of_match_node(dpu_dt_match, dev->of_node) ||
> -		of_match_node(mdp5_dt_match, dev->of_node);
> +#ifdef CONFIG_DRM_MSM_DPU
> +	if (of_match_node(dpu_dt_match, dev->of_node))
> +		return true;
> +#endif
> +
> +#ifdef CONFIG_DRM_MSM_MDP5
> +	if (of_match_node(mdp5_dt_match, dev->of_node))
> +		return true;
> +#endif
> +
> +	return false;
>   }
>   
>   static int mdss_probe(struct platform_device *pdev)