Re: [PATCH v6 4/4] drm: rcar-du: Convert LVDS encoder code to bridge driver

[Niklas Söderlund]

Hi Laurent,

Thanks for your patch.

On 2018-02-22 15:13:36 +0200, Laurent Pinchart wrote:
> The LVDS encoders used to be described in DT as part of the DU. They now
> have their own DT node, linked to the DU using the OF graph bindings.
> This allows moving internal LVDS encoder support to a separate driver
> modelled as a DRM bridge. Backward compatibility is retained as legacy
> DT is patched live to move to the new bindings.
> 
> Signed-off-by: Laurent Pinchart 

I'm not so strong when it comes to DRM, but I have done my best to grasp 
this patch. Looking at datasheets and what the code looked before feel 
free to add.

Reviewed-by: Niklas Söderlund 

> ---
> Changes since v1:
> 
> - Update the SPDX headers to use GPL-2.0 instead of GPL-2.0-only
> - Update to the -lvds compatible string format
> ---
>  drivers/gpu/drm/rcar-du/Kconfig   |   4 +-
>  drivers/gpu/drm/rcar-du/Makefile  |   3 +-
>  drivers/gpu/drm/rcar-du/rcar_du_drv.c |  21 +-
>  drivers/gpu/drm/rcar-du/rcar_du_drv.h |   5 -
>  drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 175 +-
>  drivers/gpu/drm/rcar-du/rcar_du_encoder.h |  12 -
>  drivers/gpu/drm/rcar-du/rcar_du_kms.c |  14 +-
>  drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c |  93 --
>  drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h |  24 --
>  drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 238 --
>  drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h |  64 
>  drivers/gpu/drm/rcar-du/rcar_lvds.c   | 524 
> ++
>  12 files changed, 561 insertions(+), 616 deletions(-)
>  delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c
>  delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h
>  delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
>  delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h
>  create mode 100644 drivers/gpu/drm/rcar-du/rcar_lvds.c
> 
> diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
> index 3f83352a7313..edde8d4b87a3 100644
> --- a/drivers/gpu/drm/rcar-du/Kconfig
> +++ b/drivers/gpu/drm/rcar-du/Kconfig
> @@ -19,8 +19,8 @@ config DRM_RCAR_DW_HDMI
> Enable support for R-Car Gen3 internal HDMI encoder.
>  
>  config DRM_RCAR_LVDS
> - bool "R-Car DU LVDS Encoder Support"
> - depends on DRM_RCAR_DU
> + tristate "R-Car DU LVDS Encoder Support"
> + depends on DRM && DRM_BRIDGE && OF
>   select DRM_PANEL
>   select OF_FLATTREE
>   select OF_OVERLAY
> diff --git a/drivers/gpu/drm/rcar-du/Makefile 
> b/drivers/gpu/drm/rcar-du/Makefile
> index 86b337b4be5d..3e58ed93d5b1 100644
> --- a/drivers/gpu/drm/rcar-du/Makefile
> +++ b/drivers/gpu/drm/rcar-du/Makefile
> @@ -4,10 +4,8 @@ rcar-du-drm-y := rcar_du_crtc.o \
>rcar_du_encoder.o \
>rcar_du_group.o \
>rcar_du_kms.o \
> -  rcar_du_lvdscon.o \
>rcar_du_plane.o
>  
> -rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)  += rcar_du_lvdsenc.o
>  rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)  += rcar_du_of.o \
>  rcar_du_of_lvds_r8a7790.dtb.o \
>  rcar_du_of_lvds_r8a7791.dtb.o \
> @@ -18,3 +16,4 @@ rcar-du-drm-$(CONFIG_DRM_RCAR_VSP)  += rcar_du_vsp.o
>  
>  obj-$(CONFIG_DRM_RCAR_DU)+= rcar-du-drm.o
>  obj-$(CONFIG_DRM_RCAR_DW_HDMI)   += rcar_dw_hdmi.o
> +obj-$(CONFIG_DRM_RCAR_LVDS)  += rcar_lvds.o
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c 
> b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> index 6e02c762a557..06a3fbdd728a 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> @@ -29,6 +29,7 @@
>  
>  #include "rcar_du_drv.h"
>  #include "rcar_du_kms.h"
> +#include "rcar_du_of.h"
>  #include "rcar_du_regs.h"
>  
>  /* 
> -
> @@ -74,7 +75,6 @@ static const struct rcar_du_device_info 
> rzg1_du_r8a7745_info = {
>   .port = 1,
>   },
>   },
> - .num_lvds = 0,
>  };
>  
>  static const struct rcar_du_device_info rcar_du_r8a7779_info = {
> @@ -95,14 +95,13 @@ static const struct rcar_du_device_info 
> rcar_du_r8a7779_info = {
>   .port = 1,
>   },
>   },
> - .num_lvds = 0,
>  };
>  
>  static const struct rcar_du_device_info rcar_du_r8a7790_info = {
>   .gen = 2,
>   .features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK
> | RCAR_DU_FEATURE_EXT_CTRL_REGS,
> - .quirks = RCAR_DU_QUIRK_ALIGN_128B | RCAR_DU_QUIRK_LVDS_LANES,
> + .quirks = RCAR_DU_QUIRK_ALIGN_128B,
>   .num_crtcs = 3,
>   .routes = {
>   /*
> @@ -164,7 +163,6 @@ static const struct rcar_du_device_info 
> rcar_du_r8a7792_info = {
>   .port = 1,
>   },
>   },
> - .num_lvds = 0,
>  };
>  
>  static const 

[PATCH v6 4/4] drm: rcar-du: Convert LVDS encoder code to bridge driver

[Laurent Pinchart]

The LVDS encoders used to be described in DT as part of the DU. They now
have their own DT node, linked to the DU using the OF graph bindings.
This allows moving internal LVDS encoder support to a separate driver
modelled as a DRM bridge. Backward compatibility is retained as legacy
DT is patched live to move to the new bindings.

Signed-off-by: Laurent Pinchart 
---
Changes since v1:

- Update the SPDX headers to use GPL-2.0 instead of GPL-2.0-only
- Update to the -lvds compatible string format
---
 drivers/gpu/drm/rcar-du/Kconfig   |   4 +-
 drivers/gpu/drm/rcar-du/Makefile  |   3 +-
 drivers/gpu/drm/rcar-du/rcar_du_drv.c |  21 +-
 drivers/gpu/drm/rcar-du/rcar_du_drv.h |   5 -
 drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 175 +-
 drivers/gpu/drm/rcar-du/rcar_du_encoder.h |  12 -
 drivers/gpu/drm/rcar-du/rcar_du_kms.c |  14 +-
 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c |  93 --
 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h |  24 --
 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 238 --
 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h |  64 
 drivers/gpu/drm/rcar-du/rcar_lvds.c   | 524 ++
 12 files changed, 561 insertions(+), 616 deletions(-)
 delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c
 delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h
 delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
 delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h
 create mode 100644 drivers/gpu/drm/rcar-du/rcar_lvds.c

diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
index 3f83352a7313..edde8d4b87a3 100644
--- a/drivers/gpu/drm/rcar-du/Kconfig
+++ b/drivers/gpu/drm/rcar-du/Kconfig
@@ -19,8 +19,8 @@ config DRM_RCAR_DW_HDMI
  Enable support for R-Car Gen3 internal HDMI encoder.
 
 config DRM_RCAR_LVDS
-   bool "R-Car DU LVDS Encoder Support"
-   depends on DRM_RCAR_DU
+   tristate "R-Car DU LVDS Encoder Support"
+   depends on DRM && DRM_BRIDGE && OF
select DRM_PANEL
select OF_FLATTREE
select OF_OVERLAY
diff --git a/drivers/gpu/drm/rcar-du/Makefile b/drivers/gpu/drm/rcar-du/Makefile
index 86b337b4be5d..3e58ed93d5b1 100644
--- a/drivers/gpu/drm/rcar-du/Makefile
+++ b/drivers/gpu/drm/rcar-du/Makefile
@@ -4,10 +4,8 @@ rcar-du-drm-y := rcar_du_crtc.o \
 rcar_du_encoder.o \
 rcar_du_group.o \
 rcar_du_kms.o \
-rcar_du_lvdscon.o \
 rcar_du_plane.o
 
-rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)+= rcar_du_lvdsenc.o
 rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)+= rcar_du_of.o \
   rcar_du_of_lvds_r8a7790.dtb.o \
   rcar_du_of_lvds_r8a7791.dtb.o \
@@ -18,3 +16,4 @@ rcar-du-drm-$(CONFIG_DRM_RCAR_VSP)+= rcar_du_vsp.o
 
 obj-$(CONFIG_DRM_RCAR_DU)  += rcar-du-drm.o
 obj-$(CONFIG_DRM_RCAR_DW_HDMI) += rcar_dw_hdmi.o
+obj-$(CONFIG_DRM_RCAR_LVDS)+= rcar_lvds.o
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c 
b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index 6e02c762a557..06a3fbdd728a 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -29,6 +29,7 @@
 
 #include "rcar_du_drv.h"
 #include "rcar_du_kms.h"
+#include "rcar_du_of.h"
 #include "rcar_du_regs.h"
 
 /* 
-
@@ -74,7 +75,6 @@ static const struct rcar_du_device_info rzg1_du_r8a7745_info 
= {
.port = 1,
},
},
-   .num_lvds = 0,
 };
 
 static const struct rcar_du_device_info rcar_du_r8a7779_info = {
@@ -95,14 +95,13 @@ static const struct rcar_du_device_info 
rcar_du_r8a7779_info = {
.port = 1,
},
},
-   .num_lvds = 0,
 };
 
 static const struct rcar_du_device_info rcar_du_r8a7790_info = {
.gen = 2,
.features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK
  | RCAR_DU_FEATURE_EXT_CTRL_REGS,
-   .quirks = RCAR_DU_QUIRK_ALIGN_128B | RCAR_DU_QUIRK_LVDS_LANES,
+   .quirks = RCAR_DU_QUIRK_ALIGN_128B,
.num_crtcs = 3,
.routes = {
/*
@@ -164,7 +163,6 @@ static const struct rcar_du_device_info 
rcar_du_r8a7792_info = {
.port = 1,
},
},
-   .num_lvds = 0,
 };
 
 static const struct rcar_du_device_info rcar_du_r8a7794_info = {
@@ -186,7 +184,6 @@ static const struct rcar_du_device_info 
rcar_du_r8a7794_info = {
.port = 1,
},
},
-   .num_lvds = 0,
 };
 
 static const struct rcar_du_device_info rcar_du_r8a7795_info = {
@@ -434,7 +431,19 @@ static struct platform_driver rcar_du_platform_driver = {
},
 };
 
-module_platform_driver(rcar_du_platform_driver);
+static int __init rcar_du_init(void)
+{
+