Re: [PATCH v4 04/15] drm/bridge: tc358764: add drm_panel_bridge support

2020-09-03 Thread Andrzej Hajda 
Hi Laurent,

On 03.09.2020 11:59, Laurent Pinchart wrote:
> Hi Andrzej,
>
> On Thu, Sep 03, 2020 at 11:40:58AM +0200, Andrzej Hajda wrote:
>> On 26.07.2020 22:33, Sam Ravnborg wrote:
>>> Prepare the tc358764 bridge driver for use in a chained setup by
>>> replacing direct use of drm_panel with drm_panel_bridge support.
>>>
>>> The bridge panel will use the connector type reported by the panel,
>>> where the connector for this driver hardcodes DRM_MODE_CONNECTOR_LVDS.
>>>
>>> The tc358764 did not any additional info the the connector so the
>>> connector creation is passed to the bridge panel driver.
>>>
>>> v3:
>>> - Merge with patch to make connector creation optional to avoid
>>>   creating two connectors (Laurent)
>>> - Pass connector creation to bridge panel, as this bridge driver
>>>   did not add any extra info to the connector.
>>> - Set bridge.type to DRM_MODE_CONNECTOR_LVDS.
>>>
>>> v2:
>>> - Use PTR_ERR_OR_ZERO() (kbuild test robot)
>>>
>>> Signed-off-by: Sam Ravnborg 
>>> Cc: Laurent Pinchart 
>>> Cc: kbuild test robot 
>>> Cc: Andrzej Hajda 
>>> Cc: Neil Armstrong 
>>> Cc: Jonas Karlman 
>>> Cc: Jernej Skrabec 
>>> ---
>>>drivers/gpu/drm/bridge/tc358764.c | 107 +-
>>>1 file changed, 16 insertions(+), 91 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/tc358764.c 
>>> b/drivers/gpu/drm/bridge/tc358764.c
>>> index a277739fab58..fdde4cfdc724 100644
>>> --- a/drivers/gpu/drm/bridge/tc358764.c
>>> +++ b/drivers/gpu/drm/bridge/tc358764.c
>>> @@ -153,10 +153,9 @@ static const char * const tc358764_supplies[] = {
>>>struct tc358764 {
>>> struct device *dev;
>>> struct drm_bridge bridge;
>>> -   struct drm_connector connector;
>>> struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
>>> struct gpio_desc *gpio_reset;
>>> -   struct drm_panel *panel;
>>> +   struct drm_bridge *panel_bridge;
>>> int error;
>>>};
>>>
>>> @@ -210,12 +209,6 @@ static inline struct tc358764 
>>> *bridge_to_tc358764(struct drm_bridge *bridge)
>>> return container_of(bridge, struct tc358764, bridge);
>>>}
>>>
>>> -static inline
>>> -struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
>>> -{
>>> -   return container_of(connector, struct tc358764, connector);
>>> -}
>>> -
>>>static int tc358764_init(struct tc358764 *ctx)
>>>{
>>> u32 v = 0;
>>> @@ -278,43 +271,11 @@ static void tc358764_reset(struct tc358764 *ctx)
>>> usleep_range(1000, 2000);
>>>}
>>>
>>> -static int tc358764_get_modes(struct drm_connector *connector)
>>> -{
>>> -   struct tc358764 *ctx = connector_to_tc358764(connector);
>>> -
>>> -   return drm_panel_get_modes(ctx->panel, connector);
>>> -}
>>> -
>>> -static const
>>> -struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
>>> -   .get_modes = tc358764_get_modes,
>>> -};
>>> -
>>> -static const struct drm_connector_funcs tc358764_connector_funcs = {
>>> -   .fill_modes = drm_helper_probe_single_connector_modes,
>>> -   .destroy = drm_connector_cleanup,
>>> -   .reset = drm_atomic_helper_connector_reset,
>>> -   .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>>> -   .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>>> -};
>>> -
>>> -static void tc358764_disable(struct drm_bridge *bridge)
>>> -{
>>> -   struct tc358764 *ctx = bridge_to_tc358764(bridge);
>>> -   int ret = drm_panel_disable(bridge_to_tc358764(bridge)->panel);
>>> -
>>> -   if (ret < 0)
>>> -   dev_err(ctx->dev, "error disabling panel (%d)\n", ret);
>>> -}
>>> -
>>>static void tc358764_post_disable(struct drm_bridge *bridge)
>>>{
>>> struct tc358764 *ctx = bridge_to_tc358764(bridge);
>>> int ret;
>>>
>>> -   ret = drm_panel_unprepare(ctx->panel);
>>> -   if (ret < 0)
>>> -   dev_err(ctx->dev, "error unpreparing panel (%d)\n", ret);
>>
>> Using this bridge_panel thing you reverse order of hw
>> initialization/de-initialization, this is incorrect.
>>
>> For example:
>>
>> - panel_unprepare should be called before tc35* turn off,
>>
>> - panel_prepare should be called after tc35* on.
>>
>> This is why I avoid the whole "bridge chaining" - it enforces ridiculous
>> order of initialization.
>>
>>
>>> tc358764_reset(ctx);
>>> usleep_range(1, 15000);
>>> ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
>>> @@ -335,70 +296,28 @@ static void tc358764_pre_enable(struct drm_bridge 
>>> *bridge)
>>> ret = tc358764_init(ctx);
>>> if (ret < 0)
>>> dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
>>> -   ret = drm_panel_prepare(ctx->panel);
>>> -   if (ret < 0)
>>> -   dev_err(ctx->dev, "error preparing panel (%d)\n", ret);
>>> -}
>>> -
>>> -static void tc358764_enable(struct drm_bridge *bridge)
>>> -{
>>> -   struct tc358764 *ctx = bridge_to_tc358764(bridge);
>>> -   int ret = drm_panel_enable(ctx->panel);
>>> -
>>> -   if (ret

Re: [PATCH v4 04/15] drm/bridge: tc358764: add drm_panel_bridge support

2020-09-03 Thread Laurent Pinchart 
Hi Andrzej,

On Thu, Sep 03, 2020 at 11:40:58AM +0200, Andrzej Hajda wrote:
> On 26.07.2020 22:33, Sam Ravnborg wrote:
> > Prepare the tc358764 bridge driver for use in a chained setup by
> > replacing direct use of drm_panel with drm_panel_bridge support.
> >
> > The bridge panel will use the connector type reported by the panel,
> > where the connector for this driver hardcodes DRM_MODE_CONNECTOR_LVDS.
> >
> > The tc358764 did not any additional info the the connector so the
> > connector creation is passed to the bridge panel driver.
> >
> > v3:
> >- Merge with patch to make connector creation optional to avoid
> >  creating two connectors (Laurent)
> >- Pass connector creation to bridge panel, as this bridge driver
> >  did not add any extra info to the connector.
> >- Set bridge.type to DRM_MODE_CONNECTOR_LVDS.
> >
> > v2:
> >- Use PTR_ERR_OR_ZERO() (kbuild test robot)
> >
> > Signed-off-by: Sam Ravnborg 
> > Cc: Laurent Pinchart 
> > Cc: kbuild test robot 
> > Cc: Andrzej Hajda 
> > Cc: Neil Armstrong 
> > Cc: Jonas Karlman 
> > Cc: Jernej Skrabec 
> > ---
> >   drivers/gpu/drm/bridge/tc358764.c | 107 +-
> >   1 file changed, 16 insertions(+), 91 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/tc358764.c 
> > b/drivers/gpu/drm/bridge/tc358764.c
> > index a277739fab58..fdde4cfdc724 100644
> > --- a/drivers/gpu/drm/bridge/tc358764.c
> > +++ b/drivers/gpu/drm/bridge/tc358764.c
> > @@ -153,10 +153,9 @@ static const char * const tc358764_supplies[] = {
> >   struct tc358764 {
> > struct device *dev;
> > struct drm_bridge bridge;
> > -   struct drm_connector connector;
> > struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
> > struct gpio_desc *gpio_reset;
> > -   struct drm_panel *panel;
> > +   struct drm_bridge *panel_bridge;
> > int error;
> >   };
> >   
> > @@ -210,12 +209,6 @@ static inline struct tc358764 
> > *bridge_to_tc358764(struct drm_bridge *bridge)
> > return container_of(bridge, struct tc358764, bridge);
> >   }
> >   
> > -static inline
> > -struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
> > -{
> > -   return container_of(connector, struct tc358764, connector);
> > -}
> > -
> >   static int tc358764_init(struct tc358764 *ctx)
> >   {
> > u32 v = 0;
> > @@ -278,43 +271,11 @@ static void tc358764_reset(struct tc358764 *ctx)
> > usleep_range(1000, 2000);
> >   }
> >   
> > -static int tc358764_get_modes(struct drm_connector *connector)
> > -{
> > -   struct tc358764 *ctx = connector_to_tc358764(connector);
> > -
> > -   return drm_panel_get_modes(ctx->panel, connector);
> > -}
> > -
> > -static const
> > -struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
> > -   .get_modes = tc358764_get_modes,
> > -};
> > -
> > -static const struct drm_connector_funcs tc358764_connector_funcs = {
> > -   .fill_modes = drm_helper_probe_single_connector_modes,
> > -   .destroy = drm_connector_cleanup,
> > -   .reset = drm_atomic_helper_connector_reset,
> > -   .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> > -   .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > -};
> > -
> > -static void tc358764_disable(struct drm_bridge *bridge)
> > -{
> > -   struct tc358764 *ctx = bridge_to_tc358764(bridge);
> > -   int ret = drm_panel_disable(bridge_to_tc358764(bridge)->panel);
> > -
> > -   if (ret < 0)
> > -   dev_err(ctx->dev, "error disabling panel (%d)\n", ret);
> > -}
> > -
> >   static void tc358764_post_disable(struct drm_bridge *bridge)
> >   {
> > struct tc358764 *ctx = bridge_to_tc358764(bridge);
> > int ret;
> >   
> > -   ret = drm_panel_unprepare(ctx->panel);
> > -   if (ret < 0)
> > -   dev_err(ctx->dev, "error unpreparing panel (%d)\n", ret);
> 
> 
> Using this bridge_panel thing you reverse order of hw 
> initialization/de-initialization, this is incorrect.
> 
> For example:
> 
> - panel_unprepare should be called before tc35* turn off,
> 
> - panel_prepare should be called after tc35* on.
> 
> This is why I avoid the whole "bridge chaining" - it enforces ridiculous 
> order of initialization.
> 
> 
> > tc358764_reset(ctx);
> > usleep_range(1, 15000);
> > ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> > @@ -335,70 +296,28 @@ static void tc358764_pre_enable(struct drm_bridge 
> > *bridge)
> > ret = tc358764_init(ctx);
> > if (ret < 0)
> > dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
> > -   ret = drm_panel_prepare(ctx->panel);
> > -   if (ret < 0)
> > -   dev_err(ctx->dev, "error preparing panel (%d)\n", ret);
> > -}
> > -
> > -static void tc358764_enable(struct drm_bridge *bridge)
> > -{
> > -   struct tc358764 *ctx = bridge_to_tc358764(bridge);
> > -   int ret = drm_panel_enable(ctx->panel);
> > -
> > -   if (ret < 0)
> > -   dev_err(ctx->dev, "error enabling panel (%d)\n", ret);
> >   }
>

Re: [PATCH v4 04/15] drm/bridge: tc358764: add drm_panel_bridge support

2020-09-03 Thread Andrzej Hajda 


On 26.07.2020 22:33, Sam Ravnborg wrote:
> Prepare the tc358764 bridge driver for use in a chained setup by
> replacing direct use of drm_panel with drm_panel_bridge support.
>
> The bridge panel will use the connector type reported by the panel,
> where the connector for this driver hardcodes DRM_MODE_CONNECTOR_LVDS.
>
> The tc358764 did not any additional info the the connector so the
> connector creation is passed to the bridge panel driver.
>
> v3:
>- Merge with patch to make connector creation optional to avoid
>  creating two connectors (Laurent)
>- Pass connector creation to bridge panel, as this bridge driver
>  did not add any extra info to the connector.
>- Set bridge.type to DRM_MODE_CONNECTOR_LVDS.
>
> v2:
>- Use PTR_ERR_OR_ZERO() (kbuild test robot)
>
> Signed-off-by: Sam Ravnborg 
> Cc: Laurent Pinchart 
> Cc: kbuild test robot 
> Cc: Andrzej Hajda 
> Cc: Neil Armstrong 
> Cc: Jonas Karlman 
> Cc: Jernej Skrabec 
> ---
>   drivers/gpu/drm/bridge/tc358764.c | 107 +-
>   1 file changed, 16 insertions(+), 91 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358764.c 
> b/drivers/gpu/drm/bridge/tc358764.c
> index a277739fab58..fdde4cfdc724 100644
> --- a/drivers/gpu/drm/bridge/tc358764.c
> +++ b/drivers/gpu/drm/bridge/tc358764.c
> @@ -153,10 +153,9 @@ static const char * const tc358764_supplies[] = {
>   struct tc358764 {
>   struct device *dev;
>   struct drm_bridge bridge;
> - struct drm_connector connector;
>   struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
>   struct gpio_desc *gpio_reset;
> - struct drm_panel *panel;
> + struct drm_bridge *panel_bridge;
>   int error;
>   };
>   
> @@ -210,12 +209,6 @@ static inline struct tc358764 *bridge_to_tc358764(struct 
> drm_bridge *bridge)
>   return container_of(bridge, struct tc358764, bridge);
>   }
>   
> -static inline
> -struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
> -{
> - return container_of(connector, struct tc358764, connector);
> -}
> -
>   static int tc358764_init(struct tc358764 *ctx)
>   {
>   u32 v = 0;
> @@ -278,43 +271,11 @@ static void tc358764_reset(struct tc358764 *ctx)
>   usleep_range(1000, 2000);
>   }
>   
> -static int tc358764_get_modes(struct drm_connector *connector)
> -{
> - struct tc358764 *ctx = connector_to_tc358764(connector);
> -
> - return drm_panel_get_modes(ctx->panel, connector);
> -}
> -
> -static const
> -struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
> - .get_modes = tc358764_get_modes,
> -};
> -
> -static const struct drm_connector_funcs tc358764_connector_funcs = {
> - .fill_modes = drm_helper_probe_single_connector_modes,
> - .destroy = drm_connector_cleanup,
> - .reset = drm_atomic_helper_connector_reset,
> - .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> - .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> -};
> -
> -static void tc358764_disable(struct drm_bridge *bridge)
> -{
> - struct tc358764 *ctx = bridge_to_tc358764(bridge);
> - int ret = drm_panel_disable(bridge_to_tc358764(bridge)->panel);
> -
> - if (ret < 0)
> - dev_err(ctx->dev, "error disabling panel (%d)\n", ret);
> -}
> -
>   static void tc358764_post_disable(struct drm_bridge *bridge)
>   {
>   struct tc358764 *ctx = bridge_to_tc358764(bridge);
>   int ret;
>   
> - ret = drm_panel_unprepare(ctx->panel);
> - if (ret < 0)
> - dev_err(ctx->dev, "error unpreparing panel (%d)\n", ret);


Using this bridge_panel thing you reverse order of hw 
initialization/de-initialization, this is incorrect.

For example:

- panel_unprepare should be called before tc35* turn off,

- panel_prepare should be called after tc35* on.

This is why I avoid the whole "bridge chaining" - it enforces ridiculous 
order of initialization.


>   tc358764_reset(ctx);
>   usleep_range(1, 15000);
>   ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> @@ -335,70 +296,28 @@ static void tc358764_pre_enable(struct drm_bridge 
> *bridge)
>   ret = tc358764_init(ctx);
>   if (ret < 0)
>   dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
> - ret = drm_panel_prepare(ctx->panel);
> - if (ret < 0)
> - dev_err(ctx->dev, "error preparing panel (%d)\n", ret);
> -}
> -
> -static void tc358764_enable(struct drm_bridge *bridge)
> -{
> - struct tc358764 *ctx = bridge_to_tc358764(bridge);
> - int ret = drm_panel_enable(ctx->panel);
> -
> - if (ret < 0)
> - dev_err(ctx->dev, "error enabling panel (%d)\n", ret);
>   }
>   
>   static int tc358764_attach(struct drm_bridge *bridge,
>  enum drm_bridge_attach_flags flags)
> -{
> - struct tc358764 *ctx = bridge_to_tc358764(bridge);
> - struct drm_device *drm = bridge->dev;
> - int ret;
> -
> - if (

Re: [PATCH v4 04/15] drm/bridge: tc358764: add drm_panel_bridge support

2020-07-26 Thread Laurent Pinchart 
Hi Sam,

Thank you for the patch.

On Sun, Jul 26, 2020 at 10:33:13PM +0200, Sam Ravnborg wrote:
> Prepare the tc358764 bridge driver for use in a chained setup by
> replacing direct use of drm_panel with drm_panel_bridge support.
> 
> The bridge panel will use the connector type reported by the panel,
> where the connector for this driver hardcodes DRM_MODE_CONNECTOR_LVDS.
> 
> The tc358764 did not any additional info the the connector so the

Did you mean s/did not any/did not add any/ ?
s/the the/to the/

> connector creation is passed to the bridge panel driver.
> 
> v3:
>   - Merge with patch to make connector creation optional to avoid
> creating two connectors (Laurent)
>   - Pass connector creation to bridge panel, as this bridge driver
> did not add any extra info to the connector.
>   - Set bridge.type to DRM_MODE_CONNECTOR_LVDS.
> 
> v2:
>   - Use PTR_ERR_OR_ZERO() (kbuild test robot)
> 
> Signed-off-by: Sam Ravnborg 
> Cc: Laurent Pinchart 
> Cc: kbuild test robot 
> Cc: Andrzej Hajda 
> Cc: Neil Armstrong 
> Cc: Jonas Karlman 
> Cc: Jernej Skrabec 
> ---
>  drivers/gpu/drm/bridge/tc358764.c | 107 +-
>  1 file changed, 16 insertions(+), 91 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/tc358764.c 
> b/drivers/gpu/drm/bridge/tc358764.c
> index a277739fab58..fdde4cfdc724 100644
> --- a/drivers/gpu/drm/bridge/tc358764.c
> +++ b/drivers/gpu/drm/bridge/tc358764.c
> @@ -153,10 +153,9 @@ static const char * const tc358764_supplies[] = {
>  struct tc358764 {
>   struct device *dev;
>   struct drm_bridge bridge;
> - struct drm_connector connector;
>   struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
>   struct gpio_desc *gpio_reset;
> - struct drm_panel *panel;
> + struct drm_bridge *panel_bridge;
>   int error;
>  };
>  
> @@ -210,12 +209,6 @@ static inline struct tc358764 *bridge_to_tc358764(struct 
> drm_bridge *bridge)
>   return container_of(bridge, struct tc358764, bridge);
>  }
>  
> -static inline
> -struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
> -{
> - return container_of(connector, struct tc358764, connector);
> -}
> -
>  static int tc358764_init(struct tc358764 *ctx)
>  {
>   u32 v = 0;
> @@ -278,43 +271,11 @@ static void tc358764_reset(struct tc358764 *ctx)
>   usleep_range(1000, 2000);
>  }
>  
> -static int tc358764_get_modes(struct drm_connector *connector)
> -{
> - struct tc358764 *ctx = connector_to_tc358764(connector);
> -
> - return drm_panel_get_modes(ctx->panel, connector);
> -}
> -
> -static const
> -struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
> - .get_modes = tc358764_get_modes,
> -};
> -
> -static const struct drm_connector_funcs tc358764_connector_funcs = {
> - .fill_modes = drm_helper_probe_single_connector_modes,
> - .destroy = drm_connector_cleanup,
> - .reset = drm_atomic_helper_connector_reset,
> - .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> - .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> -};
> -
> -static void tc358764_disable(struct drm_bridge *bridge)
> -{
> - struct tc358764 *ctx = bridge_to_tc358764(bridge);
> - int ret = drm_panel_disable(bridge_to_tc358764(bridge)->panel);
> -
> - if (ret < 0)
> - dev_err(ctx->dev, "error disabling panel (%d)\n", ret);
> -}
> -
>  static void tc358764_post_disable(struct drm_bridge *bridge)
>  {
>   struct tc358764 *ctx = bridge_to_tc358764(bridge);
>   int ret;
>  
> - ret = drm_panel_unprepare(ctx->panel);
> - if (ret < 0)
> - dev_err(ctx->dev, "error unpreparing panel (%d)\n", ret);
>   tc358764_reset(ctx);
>   usleep_range(1, 15000);
>   ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> @@ -335,70 +296,28 @@ static void tc358764_pre_enable(struct drm_bridge 
> *bridge)
>   ret = tc358764_init(ctx);
>   if (ret < 0)
>   dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
> - ret = drm_panel_prepare(ctx->panel);
> - if (ret < 0)
> - dev_err(ctx->dev, "error preparing panel (%d)\n", ret);
> -}
> -
> -static void tc358764_enable(struct drm_bridge *bridge)
> -{
> - struct tc358764 *ctx = bridge_to_tc358764(bridge);
> - int ret = drm_panel_enable(ctx->panel);
> -
> - if (ret < 0)
> - dev_err(ctx->dev, "error enabling panel (%d)\n", ret);
>  }
>  
>  static int tc358764_attach(struct drm_bridge *bridge,
>  enum drm_bridge_attach_flags flags)
> -{
> - struct tc358764 *ctx = bridge_to_tc358764(bridge);
> - struct drm_device *drm = bridge->dev;
> - int ret;
> -
> - if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
> - DRM_ERROR("Fix bridge driver to make connector optional!");
> - return -EINVAL;
> - }
> -
> - ctx->connector.polled = DRM_CONNECTOR_POLL_HPD;
> - ret

[PATCH v4 04/15] drm/bridge: tc358764: add drm_panel_bridge support

2020-07-26 Thread Sam Ravnborg 
Prepare the tc358764 bridge driver for use in a chained setup by
replacing direct use of drm_panel with drm_panel_bridge support.

The bridge panel will use the connector type reported by the panel,
where the connector for this driver hardcodes DRM_MODE_CONNECTOR_LVDS.

The tc358764 did not any additional info the the connector so the
connector creation is passed to the bridge panel driver.

v3:
  - Merge with patch to make connector creation optional to avoid
creating two connectors (Laurent)
  - Pass connector creation to bridge panel, as this bridge driver
did not add any extra info to the connector.
  - Set bridge.type to DRM_MODE_CONNECTOR_LVDS.

v2:
  - Use PTR_ERR_OR_ZERO() (kbuild test robot)

Signed-off-by: Sam Ravnborg 
Cc: Laurent Pinchart 
Cc: kbuild test robot 
Cc: Andrzej Hajda 
Cc: Neil Armstrong 
Cc: Jonas Karlman 
Cc: Jernej Skrabec 
---
 drivers/gpu/drm/bridge/tc358764.c | 107 +-
 1 file changed, 16 insertions(+), 91 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358764.c 
b/drivers/gpu/drm/bridge/tc358764.c
index a277739fab58..fdde4cfdc724 100644
--- a/drivers/gpu/drm/bridge/tc358764.c
+++ b/drivers/gpu/drm/bridge/tc358764.c
@@ -153,10 +153,9 @@ static const char * const tc358764_supplies[] = {
 struct tc358764 {
struct device *dev;
struct drm_bridge bridge;
-   struct drm_connector connector;
struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
struct gpio_desc *gpio_reset;
-   struct drm_panel *panel;
+   struct drm_bridge *panel_bridge;
int error;
 };
 
@@ -210,12 +209,6 @@ static inline struct tc358764 *bridge_to_tc358764(struct 
drm_bridge *bridge)
return container_of(bridge, struct tc358764, bridge);
 }
 
-static inline
-struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
-{
-   return container_of(connector, struct tc358764, connector);
-}
-
 static int tc358764_init(struct tc358764 *ctx)
 {
u32 v = 0;
@@ -278,43 +271,11 @@ static void tc358764_reset(struct tc358764 *ctx)
usleep_range(1000, 2000);
 }
 
-static int tc358764_get_modes(struct drm_connector *connector)
-{
-   struct tc358764 *ctx = connector_to_tc358764(connector);
-
-   return drm_panel_get_modes(ctx->panel, connector);
-}
-
-static const
-struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
-   .get_modes = tc358764_get_modes,
-};
-
-static const struct drm_connector_funcs tc358764_connector_funcs = {
-   .fill_modes = drm_helper_probe_single_connector_modes,
-   .destroy = drm_connector_cleanup,
-   .reset = drm_atomic_helper_connector_reset,
-   .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-   .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static void tc358764_disable(struct drm_bridge *bridge)
-{
-   struct tc358764 *ctx = bridge_to_tc358764(bridge);
-   int ret = drm_panel_disable(bridge_to_tc358764(bridge)->panel);
-
-   if (ret < 0)
-   dev_err(ctx->dev, "error disabling panel (%d)\n", ret);
-}
-
 static void tc358764_post_disable(struct drm_bridge *bridge)
 {
struct tc358764 *ctx = bridge_to_tc358764(bridge);
int ret;
 
-   ret = drm_panel_unprepare(ctx->panel);
-   if (ret < 0)
-   dev_err(ctx->dev, "error unpreparing panel (%d)\n", ret);
tc358764_reset(ctx);
usleep_range(1, 15000);
ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
@@ -335,70 +296,28 @@ static void tc358764_pre_enable(struct drm_bridge *bridge)
ret = tc358764_init(ctx);
if (ret < 0)
dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
-   ret = drm_panel_prepare(ctx->panel);
-   if (ret < 0)
-   dev_err(ctx->dev, "error preparing panel (%d)\n", ret);
-}
-
-static void tc358764_enable(struct drm_bridge *bridge)
-{
-   struct tc358764 *ctx = bridge_to_tc358764(bridge);
-   int ret = drm_panel_enable(ctx->panel);
-
-   if (ret < 0)
-   dev_err(ctx->dev, "error enabling panel (%d)\n", ret);
 }
 
 static int tc358764_attach(struct drm_bridge *bridge,
   enum drm_bridge_attach_flags flags)
-{
-   struct tc358764 *ctx = bridge_to_tc358764(bridge);
-   struct drm_device *drm = bridge->dev;
-   int ret;
-
-   if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
-   DRM_ERROR("Fix bridge driver to make connector optional!");
-   return -EINVAL;
-   }
-
-   ctx->connector.polled = DRM_CONNECTOR_POLL_HPD;
-   ret = drm_connector_init(drm, &ctx->connector,
-&tc358764_connector_funcs,
-DRM_MODE_CONNECTOR_LVDS);
-   if (ret) {
-   DRM_ERROR("Failed to initialize connector\n");
-   return ret;
-   }
-
-   drm_connector_helper_add(&ctx->connector,
-