RE: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-04 Thread Inki Dae


> -Original Message-
> From: Sean Paul [mailto:seanp...@chromium.org]
> Sent: Saturday, October 05, 2013 12:05 AM
> To: Inki Dae
> Cc: Kukjin Kim; DRI mailing list; linux-samsung-soc; Linux ARM Kernel;
> Linux Kernel Mailing List; linux-...@vger.kernel.org;
> devicet...@vger.kernel.org; Dave Airlie
> Subject: Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present
> 
> On Fri, Oct 4, 2013 at 11:01 AM, Inki Dae  wrote:
> >
> >
> >> -Original Message-
> >> From: Sean Paul [mailto:seanp...@chromium.org]
> >> Sent: Friday, October 04, 2013 11:17 PM
> >> To: Inki Dae
> >> Cc: Kukjin Kim; DRI mailing list; linux-samsung-soc@vger.kernel.org;
> >> linux-arm-ker...@lists.infradead.org; linux-ker...@vger.kernel.org;
> linux-
> >> d...@vger.kernel.org; devicet...@vger.kernel.org; Dave Airlie
> >> Subject: Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present
> >>
> >> On Fri, Oct 4, 2013 at 12:18 AM, Inki Dae  wrote:
> >> > 2013/10/4 Sean Paul :
> >> >> On Thu, Oct 3, 2013 at 10:29 PM, Inki Dae 
> wrote:
> >> >>> 2013/10/4 Sean Paul :
> >> >>>> This patch adds code to look for the ptn3460 in the device tree
> file
> >> on
> >> >>>> exynos initialization. If ptn node is found, the driver will
> >> initialize
> >> >>>> the ptn3460 driver and skip creating a DP connector (since the
> bridge
> >> >>>> driver will register its own connector).
> >> >>>>
> >> >>>> Signed-off-by: Sean Paul 
> >> >>>> ---
> >> >>>>
> >> >>>> v2:
> >> >>>> - Changed include from of_i2c.h to i2c.h
> >> >>>> - Changed of_find_by_name to of_find_compatible
> >> >>>>
> >> >>>>  drivers/gpu/drm/exynos/exynos_drm_core.c | 44
> >> +++-
> >> >>>>  1 file changed, 43 insertions(+), 1 deletion(-)
> >> >>>>
> >> >>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c
> >> b/drivers/gpu/drm/exynos/exynos_drm_core.c
> >> >>>> index 1bef6dc..08ca4f9 100644
> >> >>>> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
> >> >>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
> >> >>>> @@ -12,7 +12,9 @@
> >> >>>>   * option) any later version.
> >> >>>>   */
> >> >>>>
> >> >>>> +#include 
> >> >>>>  #include 
> >> >>>> +#include 
> >> >>>>  #include "exynos_drm_drv.h"
> >> >>>>  #include "exynos_drm_encoder.h"
> >> >>>>  #include "exynos_drm_connector.h"
> >> >>>> @@ -20,6 +22,40 @@
> >> >>>>
> >> >>>>  static LIST_HEAD(exynos_drm_subdrv_list);
> >> >>>>
> >> >>>> +struct bridge_init {
> >> >>>> +   struct i2c_client *client;
> >> >>>> +   struct device_node *node;
> >> >>>> +};
> >> >>>> +
> >> >>>> +static bool find_bridge(const char *compat, struct bridge_init
> >> *bridge)
> >> >>>> +{
> >> >>>> +   bridge->client = NULL;
> >> >>>> +   bridge->node = of_find_compatible_node(NULL, NULL,
compat);
> >> >>>
> >> >>> Then, shouldn't the lvds-bridge driver be implemented as i2c driver
> so
> >> >>> that such tricky isn't needed? Is there any reason you use such
> tricky
> >> >>> codes?
> >> >>>
> >> >>
> >> >> This is what I was explaining earlier today. If the bridge driver is
> >> >> just an i2c driver, it won't get a pointer to drm_device, and can't
> >> >> register itself as a drm_bridge or drm_connector. To solve this, you
> >> >> need the ptn3460_init callback.
> >> >>
> >> >
> >> > No, I think you can use sub driver. how about registering to exynos
> >> > drm core that driver using exynos_drm_subdrv_register function after
> >> > probed? Is there something I am missing?
> >> >
> >>
> >> The ptn driver isn't exynos-specific, so I don't think maki

Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-04 Thread Sean Paul
On Fri, Oct 4, 2013 at 11:01 AM, Inki Dae  wrote:
>
>
>> -Original Message-
>> From: Sean Paul [mailto:seanp...@chromium.org]
>> Sent: Friday, October 04, 2013 11:17 PM
>> To: Inki Dae
>> Cc: Kukjin Kim; DRI mailing list; linux-samsung-soc@vger.kernel.org;
>> linux-arm-ker...@lists.infradead.org; linux-ker...@vger.kernel.org; linux-
>> d...@vger.kernel.org; devicet...@vger.kernel.org; Dave Airlie
>> Subject: Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present
>>
>> On Fri, Oct 4, 2013 at 12:18 AM, Inki Dae  wrote:
>> > 2013/10/4 Sean Paul :
>> >> On Thu, Oct 3, 2013 at 10:29 PM, Inki Dae  wrote:
>> >>> 2013/10/4 Sean Paul :
>> >>>> This patch adds code to look for the ptn3460 in the device tree file
>> on
>> >>>> exynos initialization. If ptn node is found, the driver will
>> initialize
>> >>>> the ptn3460 driver and skip creating a DP connector (since the bridge
>> >>>> driver will register its own connector).
>> >>>>
>> >>>> Signed-off-by: Sean Paul 
>> >>>> ---
>> >>>>
>> >>>> v2:
>> >>>> - Changed include from of_i2c.h to i2c.h
>> >>>> - Changed of_find_by_name to of_find_compatible
>> >>>>
>> >>>>  drivers/gpu/drm/exynos/exynos_drm_core.c | 44
>> +++-
>> >>>>  1 file changed, 43 insertions(+), 1 deletion(-)
>> >>>>
>> >>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c
>> b/drivers/gpu/drm/exynos/exynos_drm_core.c
>> >>>> index 1bef6dc..08ca4f9 100644
>> >>>> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
>> >>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
>> >>>> @@ -12,7 +12,9 @@
>> >>>>   * option) any later version.
>> >>>>   */
>> >>>>
>> >>>> +#include 
>> >>>>  #include 
>> >>>> +#include 
>> >>>>  #include "exynos_drm_drv.h"
>> >>>>  #include "exynos_drm_encoder.h"
>> >>>>  #include "exynos_drm_connector.h"
>> >>>> @@ -20,6 +22,40 @@
>> >>>>
>> >>>>  static LIST_HEAD(exynos_drm_subdrv_list);
>> >>>>
>> >>>> +struct bridge_init {
>> >>>> +   struct i2c_client *client;
>> >>>> +   struct device_node *node;
>> >>>> +};
>> >>>> +
>> >>>> +static bool find_bridge(const char *compat, struct bridge_init
>> *bridge)
>> >>>> +{
>> >>>> +   bridge->client = NULL;
>> >>>> +   bridge->node = of_find_compatible_node(NULL, NULL, compat);
>> >>>
>> >>> Then, shouldn't the lvds-bridge driver be implemented as i2c driver so
>> >>> that such tricky isn't needed? Is there any reason you use such tricky
>> >>> codes?
>> >>>
>> >>
>> >> This is what I was explaining earlier today. If the bridge driver is
>> >> just an i2c driver, it won't get a pointer to drm_device, and can't
>> >> register itself as a drm_bridge or drm_connector. To solve this, you
>> >> need the ptn3460_init callback.
>> >>
>> >
>> > No, I think you can use sub driver. how about registering to exynos
>> > drm core that driver using exynos_drm_subdrv_register function after
>> > probed? Is there something I am missing?
>> >
>>
>> The ptn driver isn't exynos-specific, so I don't think making it an
>> exynos_drm_subdrv is appropriate.
>>
>
> I _really know_ that the ptn driver isn't exynos-specific. I mean that you
> can use exynos_drm_subdrv somehow. ie. you can add a new bridge module
> specific to exynos, and this module can register its own sub driver at end
> of probe. Why do you try to use such tricky codes?
>

So I create a new exynos_lvds_driver which is an i2c driver. When that
probes, all it does is register that driver as an exynos_drm_subdrv.
Then in the subdrv probe I call into ptn3460_init?

That seems a lot more tricky than just calling ptn3460_init directly...

Sean


> Thanks,
> Inki Dae
>
>> Sean
>>
>> >
>> >> If it's an i2c driver with the ptn3460_init callback, where it parses
>> >> the dt in probe,

RE: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-04 Thread Inki Dae


> -Original Message-
> From: Sean Paul [mailto:seanp...@chromium.org]
> Sent: Friday, October 04, 2013 11:17 PM
> To: Inki Dae
> Cc: Kukjin Kim; DRI mailing list; linux-samsung-soc@vger.kernel.org;
> linux-arm-ker...@lists.infradead.org; linux-ker...@vger.kernel.org; linux-
> d...@vger.kernel.org; devicet...@vger.kernel.org; Dave Airlie
> Subject: Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present
> 
> On Fri, Oct 4, 2013 at 12:18 AM, Inki Dae  wrote:
> > 2013/10/4 Sean Paul :
> >> On Thu, Oct 3, 2013 at 10:29 PM, Inki Dae  wrote:
> >>> 2013/10/4 Sean Paul :
> >>>> This patch adds code to look for the ptn3460 in the device tree file
> on
> >>>> exynos initialization. If ptn node is found, the driver will
> initialize
> >>>> the ptn3460 driver and skip creating a DP connector (since the bridge
> >>>> driver will register its own connector).
> >>>>
> >>>> Signed-off-by: Sean Paul 
> >>>> ---
> >>>>
> >>>> v2:
> >>>> - Changed include from of_i2c.h to i2c.h
> >>>> - Changed of_find_by_name to of_find_compatible
> >>>>
> >>>>  drivers/gpu/drm/exynos/exynos_drm_core.c | 44
> +++-
> >>>>  1 file changed, 43 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c
> b/drivers/gpu/drm/exynos/exynos_drm_core.c
> >>>> index 1bef6dc..08ca4f9 100644
> >>>> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
> >>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
> >>>> @@ -12,7 +12,9 @@
> >>>>   * option) any later version.
> >>>>   */
> >>>>
> >>>> +#include 
> >>>>  #include 
> >>>> +#include 
> >>>>  #include "exynos_drm_drv.h"
> >>>>  #include "exynos_drm_encoder.h"
> >>>>  #include "exynos_drm_connector.h"
> >>>> @@ -20,6 +22,40 @@
> >>>>
> >>>>  static LIST_HEAD(exynos_drm_subdrv_list);
> >>>>
> >>>> +struct bridge_init {
> >>>> +   struct i2c_client *client;
> >>>> +   struct device_node *node;
> >>>> +};
> >>>> +
> >>>> +static bool find_bridge(const char *compat, struct bridge_init
> *bridge)
> >>>> +{
> >>>> +   bridge->client = NULL;
> >>>> +   bridge->node = of_find_compatible_node(NULL, NULL, compat);
> >>>
> >>> Then, shouldn't the lvds-bridge driver be implemented as i2c driver so
> >>> that such tricky isn't needed? Is there any reason you use such tricky
> >>> codes?
> >>>
> >>
> >> This is what I was explaining earlier today. If the bridge driver is
> >> just an i2c driver, it won't get a pointer to drm_device, and can't
> >> register itself as a drm_bridge or drm_connector. To solve this, you
> >> need the ptn3460_init callback.
> >>
> >
> > No, I think you can use sub driver. how about registering to exynos
> > drm core that driver using exynos_drm_subdrv_register function after
> > probed? Is there something I am missing?
> >
> 
> The ptn driver isn't exynos-specific, so I don't think making it an
> exynos_drm_subdrv is appropriate.
> 

I _really know_ that the ptn driver isn't exynos-specific. I mean that you
can use exynos_drm_subdrv somehow. ie. you can add a new bridge module
specific to exynos, and this module can register its own sub driver at end
of probe. Why do you try to use such tricky codes?

Thanks,
Inki Dae

> Sean
> 
> >
> >> If it's an i2c driver with the ptn3460_init callback, where it parses
> >> the dt in probe, then you have a race between the ptn probe and the
> >> ptn init/drm hooks. ie: it's possible drm will initialize and call
> >> disable/post_disable/pre_enable/enable before things have been probed.
> >
> > And also, exynos drm core will call a probe callback of the sub driver
> > after _drm is initialized_. Is there something I am missing?
> >
> >> To solve this, you need to use some global state and/or locking.
> >>
> >> So, to summarize. We can have this of_find_compatible with a init
> >> callback, or we can have an i2c driver + global state/locking + init
> >> callback. I chose the former, since it seeme

Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-04 Thread Sean Paul
On Fri, Oct 4, 2013 at 12:18 AM, Inki Dae  wrote:
> 2013/10/4 Sean Paul :
>> On Thu, Oct 3, 2013 at 10:29 PM, Inki Dae  wrote:
>>> 2013/10/4 Sean Paul :
 This patch adds code to look for the ptn3460 in the device tree file on
 exynos initialization. If ptn node is found, the driver will initialize
 the ptn3460 driver and skip creating a DP connector (since the bridge
 driver will register its own connector).

 Signed-off-by: Sean Paul 
 ---

 v2:
 - Changed include from of_i2c.h to i2c.h
 - Changed of_find_by_name to of_find_compatible

  drivers/gpu/drm/exynos/exynos_drm_core.c | 44 
 +++-
  1 file changed, 43 insertions(+), 1 deletion(-)

 diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c 
 b/drivers/gpu/drm/exynos/exynos_drm_core.c
 index 1bef6dc..08ca4f9 100644
 --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
 +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
 @@ -12,7 +12,9 @@
   * option) any later version.
   */

 +#include 
  #include 
 +#include 
  #include "exynos_drm_drv.h"
  #include "exynos_drm_encoder.h"
  #include "exynos_drm_connector.h"
 @@ -20,6 +22,40 @@

  static LIST_HEAD(exynos_drm_subdrv_list);

 +struct bridge_init {
 +   struct i2c_client *client;
 +   struct device_node *node;
 +};
 +
 +static bool find_bridge(const char *compat, struct bridge_init *bridge)
 +{
 +   bridge->client = NULL;
 +   bridge->node = of_find_compatible_node(NULL, NULL, compat);
>>>
>>> Then, shouldn't the lvds-bridge driver be implemented as i2c driver so
>>> that such tricky isn't needed? Is there any reason you use such tricky
>>> codes?
>>>
>>
>> This is what I was explaining earlier today. If the bridge driver is
>> just an i2c driver, it won't get a pointer to drm_device, and can't
>> register itself as a drm_bridge or drm_connector. To solve this, you
>> need the ptn3460_init callback.
>>
>
> No, I think you can use sub driver. how about registering to exynos
> drm core that driver using exynos_drm_subdrv_register function after
> probed? Is there something I am missing?
>

The ptn driver isn't exynos-specific, so I don't think making it an
exynos_drm_subdrv is appropriate.

Sean

>
>> If it's an i2c driver with the ptn3460_init callback, where it parses
>> the dt in probe, then you have a race between the ptn probe and the
>> ptn init/drm hooks. ie: it's possible drm will initialize and call
>> disable/post_disable/pre_enable/enable before things have been probed.
>
> And also, exynos drm core will call a probe callback of the sub driver
> after _drm is initialized_. Is there something I am missing?
>
>> To solve this, you need to use some global state and/or locking.
>>
>> So, to summarize. We can have this of_find_compatible with a init
>> callback, or we can have an i2c driver + global state/locking + init
>> callback. I chose the former, since it seemed easier.
>>
>> If you have a better way to achieve this, I'm definitely interested,
>> but I saw this as the lesser of two evils.
>>
>> Sean
>>
>>> I think you need to implement the lvds-bridge driver as i2c driver,
>>> and then consider how to take care of this. I mean let's find a better
>>> way how we could take care of the i2c based driver in exynos drm
>>> framework or driver. In all cases, such tricky codes are not good.
>>>
 +   if (!bridge->node)
 +   return false;
 +
 +   bridge->client = of_find_i2c_device_by_node(bridge->node);
 +   if (!bridge->client)
 +   return false;
 +
 +   return true;
 +}
 +
 +/* returns the number of bridges attached */
 +static int exynos_drm_attach_lcd_bridge(struct drm_device *dev,
 +   struct drm_encoder *encoder)
 +{
 +   struct bridge_init bridge;
 +   int ret;
 +
 +   if (find_bridge("nxp,ptn3460", &bridge)) {
 +   ret = ptn3460_init(dev, encoder, bridge.client, 
 bridge.node);
 +   if (!ret)
 +   return 1;
 +   }
 +   return 0;
 +}
 +
  static int exynos_drm_create_enc_conn(struct drm_device *dev,
 struct exynos_drm_subdrv *subdrv)
  {
 @@ -36,6 +72,13 @@ static int exynos_drm_create_enc_conn(struct drm_device 
 *dev,
 DRM_ERROR("failed to create encoder\n");
 return -EFAULT;
 }
 +   subdrv->encoder = encoder;
 +
 +   if (subdrv->manager->display_ops->type == EXYNOS_DISPLAY_TYPE_LCD) 
 {
 +   ret = exynos_drm_attach_lcd_bridge(dev, encoder);
 +   if (ret)
 +   return 0;
 +   }

 /*
  * create and initialize a connector for this sub 

Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-03 Thread Inki Dae
2013/10/4 Sean Paul :
> On Thu, Oct 3, 2013 at 10:29 PM, Inki Dae  wrote:
>> 2013/10/4 Sean Paul :
>>> This patch adds code to look for the ptn3460 in the device tree file on
>>> exynos initialization. If ptn node is found, the driver will initialize
>>> the ptn3460 driver and skip creating a DP connector (since the bridge
>>> driver will register its own connector).
>>>
>>> Signed-off-by: Sean Paul 
>>> ---
>>>
>>> v2:
>>> - Changed include from of_i2c.h to i2c.h
>>> - Changed of_find_by_name to of_find_compatible
>>>
>>>  drivers/gpu/drm/exynos/exynos_drm_core.c | 44 
>>> +++-
>>>  1 file changed, 43 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c 
>>> b/drivers/gpu/drm/exynos/exynos_drm_core.c
>>> index 1bef6dc..08ca4f9 100644
>>> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
>>> @@ -12,7 +12,9 @@
>>>   * option) any later version.
>>>   */
>>>
>>> +#include 
>>>  #include 
>>> +#include 
>>>  #include "exynos_drm_drv.h"
>>>  #include "exynos_drm_encoder.h"
>>>  #include "exynos_drm_connector.h"
>>> @@ -20,6 +22,40 @@
>>>
>>>  static LIST_HEAD(exynos_drm_subdrv_list);
>>>
>>> +struct bridge_init {
>>> +   struct i2c_client *client;
>>> +   struct device_node *node;
>>> +};
>>> +
>>> +static bool find_bridge(const char *compat, struct bridge_init *bridge)
>>> +{
>>> +   bridge->client = NULL;
>>> +   bridge->node = of_find_compatible_node(NULL, NULL, compat);
>>
>> Then, shouldn't the lvds-bridge driver be implemented as i2c driver so
>> that such tricky isn't needed? Is there any reason you use such tricky
>> codes?
>>
>
> This is what I was explaining earlier today. If the bridge driver is
> just an i2c driver, it won't get a pointer to drm_device, and can't
> register itself as a drm_bridge or drm_connector. To solve this, you
> need the ptn3460_init callback.
>

No, I think you can use sub driver. how about registering to exynos
drm core that driver using exynos_drm_subdrv_register function after
probed? Is there something I am missing?


> If it's an i2c driver with the ptn3460_init callback, where it parses
> the dt in probe, then you have a race between the ptn probe and the
> ptn init/drm hooks. ie: it's possible drm will initialize and call
> disable/post_disable/pre_enable/enable before things have been probed.

And also, exynos drm core will call a probe callback of the sub driver
after _drm is initialized_. Is there something I am missing?

> To solve this, you need to use some global state and/or locking.
>
> So, to summarize. We can have this of_find_compatible with a init
> callback, or we can have an i2c driver + global state/locking + init
> callback. I chose the former, since it seemed easier.
>
> If you have a better way to achieve this, I'm definitely interested,
> but I saw this as the lesser of two evils.
>
> Sean
>
>> I think you need to implement the lvds-bridge driver as i2c driver,
>> and then consider how to take care of this. I mean let's find a better
>> way how we could take care of the i2c based driver in exynos drm
>> framework or driver. In all cases, such tricky codes are not good.
>>
>>> +   if (!bridge->node)
>>> +   return false;
>>> +
>>> +   bridge->client = of_find_i2c_device_by_node(bridge->node);
>>> +   if (!bridge->client)
>>> +   return false;
>>> +
>>> +   return true;
>>> +}
>>> +
>>> +/* returns the number of bridges attached */
>>> +static int exynos_drm_attach_lcd_bridge(struct drm_device *dev,
>>> +   struct drm_encoder *encoder)
>>> +{
>>> +   struct bridge_init bridge;
>>> +   int ret;
>>> +
>>> +   if (find_bridge("nxp,ptn3460", &bridge)) {
>>> +   ret = ptn3460_init(dev, encoder, bridge.client, 
>>> bridge.node);
>>> +   if (!ret)
>>> +   return 1;
>>> +   }
>>> +   return 0;
>>> +}
>>> +
>>>  static int exynos_drm_create_enc_conn(struct drm_device *dev,
>>> struct exynos_drm_subdrv *subdrv)
>>>  {
>>> @@ -36,6 +72,13 @@ static int exynos_drm_create_enc_conn(struct drm_device 
>>> *dev,
>>> DRM_ERROR("failed to create encoder\n");
>>> return -EFAULT;
>>> }
>>> +   subdrv->encoder = encoder;
>>> +
>>> +   if (subdrv->manager->display_ops->type == EXYNOS_DISPLAY_TYPE_LCD) {
>>> +   ret = exynos_drm_attach_lcd_bridge(dev, encoder);
>>> +   if (ret)
>>> +   return 0;
>>> +   }
>>>
>>> /*
>>>  * create and initialize a connector for this sub driver and
>>> @@ -48,7 +91,6 @@ static int exynos_drm_create_enc_conn(struct drm_device 
>>> *dev,
>>> goto err_destroy_encoder;
>>> }
>>>
>>> -   subdrv->encoder = encoder;
>>> subdrv->connector = connector;
>>>
>>> return 0;
>>> --
>>> 1.8.4
>>>
>>> --
>>> 

Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-03 Thread Sean Paul
On Thu, Oct 3, 2013 at 10:29 PM, Inki Dae  wrote:
> 2013/10/4 Sean Paul :
>> This patch adds code to look for the ptn3460 in the device tree file on
>> exynos initialization. If ptn node is found, the driver will initialize
>> the ptn3460 driver and skip creating a DP connector (since the bridge
>> driver will register its own connector).
>>
>> Signed-off-by: Sean Paul 
>> ---
>>
>> v2:
>> - Changed include from of_i2c.h to i2c.h
>> - Changed of_find_by_name to of_find_compatible
>>
>>  drivers/gpu/drm/exynos/exynos_drm_core.c | 44 
>> +++-
>>  1 file changed, 43 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c 
>> b/drivers/gpu/drm/exynos/exynos_drm_core.c
>> index 1bef6dc..08ca4f9 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
>> @@ -12,7 +12,9 @@
>>   * option) any later version.
>>   */
>>
>> +#include 
>>  #include 
>> +#include 
>>  #include "exynos_drm_drv.h"
>>  #include "exynos_drm_encoder.h"
>>  #include "exynos_drm_connector.h"
>> @@ -20,6 +22,40 @@
>>
>>  static LIST_HEAD(exynos_drm_subdrv_list);
>>
>> +struct bridge_init {
>> +   struct i2c_client *client;
>> +   struct device_node *node;
>> +};
>> +
>> +static bool find_bridge(const char *compat, struct bridge_init *bridge)
>> +{
>> +   bridge->client = NULL;
>> +   bridge->node = of_find_compatible_node(NULL, NULL, compat);
>
> Then, shouldn't the lvds-bridge driver be implemented as i2c driver so
> that such tricky isn't needed? Is there any reason you use such tricky
> codes?
>

This is what I was explaining earlier today. If the bridge driver is
just an i2c driver, it won't get a pointer to drm_device, and can't
register itself as a drm_bridge or drm_connector. To solve this, you
need the ptn3460_init callback.

If it's an i2c driver with the ptn3460_init callback, where it parses
the dt in probe, then you have a race between the ptn probe and the
ptn init/drm hooks. ie: it's possible drm will initialize and call
disable/post_disable/pre_enable/enable before things have been probed.
To solve this, you need to use some global state and/or locking.

So, to summarize. We can have this of_find_compatible with a init
callback, or we can have an i2c driver + global state/locking + init
callback. I chose the former, since it seemed easier.

If you have a better way to achieve this, I'm definitely interested,
but I saw this as the lesser of two evils.

Sean

> I think you need to implement the lvds-bridge driver as i2c driver,
> and then consider how to take care of this. I mean let's find a better
> way how we could take care of the i2c based driver in exynos drm
> framework or driver. In all cases, such tricky codes are not good.
>
>> +   if (!bridge->node)
>> +   return false;
>> +
>> +   bridge->client = of_find_i2c_device_by_node(bridge->node);
>> +   if (!bridge->client)
>> +   return false;
>> +
>> +   return true;
>> +}
>> +
>> +/* returns the number of bridges attached */
>> +static int exynos_drm_attach_lcd_bridge(struct drm_device *dev,
>> +   struct drm_encoder *encoder)
>> +{
>> +   struct bridge_init bridge;
>> +   int ret;
>> +
>> +   if (find_bridge("nxp,ptn3460", &bridge)) {
>> +   ret = ptn3460_init(dev, encoder, bridge.client, bridge.node);
>> +   if (!ret)
>> +   return 1;
>> +   }
>> +   return 0;
>> +}
>> +
>>  static int exynos_drm_create_enc_conn(struct drm_device *dev,
>> struct exynos_drm_subdrv *subdrv)
>>  {
>> @@ -36,6 +72,13 @@ static int exynos_drm_create_enc_conn(struct drm_device 
>> *dev,
>> DRM_ERROR("failed to create encoder\n");
>> return -EFAULT;
>> }
>> +   subdrv->encoder = encoder;
>> +
>> +   if (subdrv->manager->display_ops->type == EXYNOS_DISPLAY_TYPE_LCD) {
>> +   ret = exynos_drm_attach_lcd_bridge(dev, encoder);
>> +   if (ret)
>> +   return 0;
>> +   }
>>
>> /*
>>  * create and initialize a connector for this sub driver and
>> @@ -48,7 +91,6 @@ static int exynos_drm_create_enc_conn(struct drm_device 
>> *dev,
>> goto err_destroy_encoder;
>> }
>>
>> -   subdrv->encoder = encoder;
>> subdrv->connector = connector;
>>
>> return 0;
>> --
>> 1.8.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" 
>> in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
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Re: [PATCH v2 4/5] drm/exynos: Initialize ptn3460 if present

2013-10-03 Thread Inki Dae
2013/10/4 Sean Paul :
> This patch adds code to look for the ptn3460 in the device tree file on
> exynos initialization. If ptn node is found, the driver will initialize
> the ptn3460 driver and skip creating a DP connector (since the bridge
> driver will register its own connector).
>
> Signed-off-by: Sean Paul 
> ---
>
> v2:
> - Changed include from of_i2c.h to i2c.h
> - Changed of_find_by_name to of_find_compatible
>
>  drivers/gpu/drm/exynos/exynos_drm_core.c | 44 
> +++-
>  1 file changed, 43 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c 
> b/drivers/gpu/drm/exynos/exynos_drm_core.c
> index 1bef6dc..08ca4f9 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
> @@ -12,7 +12,9 @@
>   * option) any later version.
>   */
>
> +#include 
>  #include 
> +#include 
>  #include "exynos_drm_drv.h"
>  #include "exynos_drm_encoder.h"
>  #include "exynos_drm_connector.h"
> @@ -20,6 +22,40 @@
>
>  static LIST_HEAD(exynos_drm_subdrv_list);
>
> +struct bridge_init {
> +   struct i2c_client *client;
> +   struct device_node *node;
> +};
> +
> +static bool find_bridge(const char *compat, struct bridge_init *bridge)
> +{
> +   bridge->client = NULL;
> +   bridge->node = of_find_compatible_node(NULL, NULL, compat);

Then, shouldn't the lvds-bridge driver be implemented as i2c driver so
that such tricky isn't needed? Is there any reason you use such tricky
codes?

I think you need to implement the lvds-bridge driver as i2c driver,
and then consider how to take care of this. I mean let's find a better
way how we could take care of the i2c based driver in exynos drm
framework or driver. In all cases, such tricky codes are not good.

> +   if (!bridge->node)
> +   return false;
> +
> +   bridge->client = of_find_i2c_device_by_node(bridge->node);
> +   if (!bridge->client)
> +   return false;
> +
> +   return true;
> +}
> +
> +/* returns the number of bridges attached */
> +static int exynos_drm_attach_lcd_bridge(struct drm_device *dev,
> +   struct drm_encoder *encoder)
> +{
> +   struct bridge_init bridge;
> +   int ret;
> +
> +   if (find_bridge("nxp,ptn3460", &bridge)) {
> +   ret = ptn3460_init(dev, encoder, bridge.client, bridge.node);
> +   if (!ret)
> +   return 1;
> +   }
> +   return 0;
> +}
> +
>  static int exynos_drm_create_enc_conn(struct drm_device *dev,
> struct exynos_drm_subdrv *subdrv)
>  {
> @@ -36,6 +72,13 @@ static int exynos_drm_create_enc_conn(struct drm_device 
> *dev,
> DRM_ERROR("failed to create encoder\n");
> return -EFAULT;
> }
> +   subdrv->encoder = encoder;
> +
> +   if (subdrv->manager->display_ops->type == EXYNOS_DISPLAY_TYPE_LCD) {
> +   ret = exynos_drm_attach_lcd_bridge(dev, encoder);
> +   if (ret)
> +   return 0;
> +   }
>
> /*
>  * create and initialize a connector for this sub driver and
> @@ -48,7 +91,6 @@ static int exynos_drm_create_enc_conn(struct drm_device 
> *dev,
> goto err_destroy_encoder;
> }
>
> -   subdrv->encoder = encoder;
> subdrv->connector = connector;
>
> return 0;
> --
> 1.8.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" 
> in
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