Re: [RFC v2 PATCH v3 10/14] drm/panel: add S6E3FA0 driver

[YoungJun Cho <yj44.cho@samsung.com>]

Hi Laurent,

Thank you for the comment.

On 04/22/2014 08:00 AM, Laurent Pinchart wrote:
> Hi YoungJun,
>
> Thank you for the patch.
>
> On Monday 21 April 2014 21:28:37 YoungJun Cho wrote:
>> This patch adds MIPI-DSI command mode based S6E3FA0 AMOLED LCD Panel driver.
>>
>> Changelog v2:
>> - Declares delay, size properties in probe routine instead of DT
>> Changelog v3:
>> - Moves CPU timings relevant properties from FIMD DT
>>    (commented by Laurent Pinchart, Andrzej Hajda)
>>
>> Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
>> Acked-by: Inki Dae <inki.dae@samsung.com>
>> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>   drivers/gpu/drm/panel/Kconfig         |    7 +
>>   drivers/gpu/drm/panel/Makefile        |    1 +
>>   drivers/gpu/drm/panel/panel-s6e3fa0.c |  569 ++++++++++++++++++++++++++++++
>>   3 files changed, 577 insertions(+)
>>   create mode 100644 drivers/gpu/drm/panel/panel-s6e3fa0.c
>
> [snip]
>
>> diff --git a/drivers/gpu/drm/panel/panel-s6e3fa0.c
>> b/drivers/gpu/drm/panel/panel-s6e3fa0.c new file mode 100644
>> index 0000000..1282678
>> --- /dev/null
>> +++ b/drivers/gpu/drm/panel/panel-s6e3fa0.c
>> @@ -0,0 +1,569 @@
>
> [snip]
>
>> +static int s6e3fa0_get_modes(struct drm_panel *panel)
>> +{
>> +	struct drm_connector *connector = panel->connector;
>> +	struct s6e3fa0 *ctx = panel_to_s6e3fa0(panel);
>> +	struct drm_display_mode *mode;
>> +
>> +	mode = drm_mode_create(connector->dev);
>> +	if (!mode) {
>> +		DRM_ERROR("failed to create a new display mode\n");
>> +		return 0;
>> +	}
>> +
>> +	drm_display_mode_from_videomode(&ctx->vm, mode);
>> +	mode->width_mm = ctx->width_mm;
>> +	mode->height_mm = ctx->height_mm;
>> +	connector->display_info.width_mm = mode->width_mm;
>> +	connector->display_info.height_mm = mode->height_mm;
>> +
>> +	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
>> +	mode->private = (void *)&ctx->cpu_timings;
>
> Wouldn't it make sense to create a new get_interface_params (or similar)
> operation for drm_panel to query interface configuration parameters instead of
> shoving it in the mode private field ?

You mean "new get_interface_params operation" is different from
get_modes() ?

Till now, struct drm_display_mode and most of mode relevant APIs are
only for video interface.
And CPU interface also needs video mode configurations.

I have a plan to implement the CPU interface relevant APIs like video
mode ones, but I think they should be used under current DRM mode APIs
like fill_modes, get_modes and so on.
So after that implementation, this private field will be replaced by
new ones.

Could you explain it in more detail?

Thank you.
Best regards YJ

>
>> +	drm_mode_probed_add(connector, mode);
>> +
>> +	return 1;
>> +}
>
> [snip]
>