Re: [PATCH v7 01/10] drm: bridge: Add Samsung DSIM bridge driver

Marek Szyprowski
2022-10-17T09:02:50Z

Hi,

On 17.10.2022 10:48, Marek Vasut wrote:
> On 10/17/22 09:43, Jagan Teki wrote:
>> On Mon, Oct 17, 2022 at 12:49 PM Marek Vasut <marex@denx.de> wrote:
>>> On 10/17/22 04:49, Jagan Teki wrote:
>>>> On Sun, Oct 16, 2022 at 3:16 AM Marek Vasut <marex@denx.de> wrote:
>>>>>
>>>>> On 10/5/22 17:13, Jagan Teki wrote:
>>>>>> Samsung MIPI DSIM controller is common DSI IP that can be used in
>>>>>> various
>>>>>> SoCs like Exynos, i.MX8M Mini/Nano.
>>>>>>
>>>>>> In order to access this DSI controller between various platform
>>>>>> SoCs,
>>>>>> the ideal way to incorporate this in the drm stack is via the drm
>>>>>> bridge
>>>>>> driver.
>>>>>>
>>>>>> This patch is trying to differentiate platform-specific and
>>>>>> bridge driver
>>>>>> code by maintaining exynos platform glue code in exynos_drm_dsi.c
>>>>>> driver
>>>>>> and common bridge driver code in samsung-dsim.c providing that
>>>>>> the new
>>>>>> platform-specific glue should be supported in the bridge driver,
>>>>>> unlike
>>>>>> exynos platform drm drivers.
>>>>>>
>>>>>> - Add samsung_dsim_plat_data for keeping platform-specific
>>>>>> attributes like
>>>>>>      host_ops, irq_ops, and hw_type.
>>>>>>
>>>>>> - Initialize the plat_data hooks for exynos platform in
>>>>>> exynos_drm_dsi.c.
>>>>>>
>>>>>> - samsung_dsim_probe is the common probe call across
>>>>>> exynos_drm_dsi.c and
>>>>>>      samsung-dsim.c.
>>>>>>
>>>>>> - plat_data hooks like host_ops and irq_ops are invoked during the
>>>>>>      respective bridge call chains.
>>>>>
>>>>> Maybe the Subject should say "Split ... driver" or "Move ...
>>>>> driver" ,
>>>>> since it is not adding a new driver here ?
>>>>
>>>> Though it is not added a completely new driver, it is adding more
>>>> infrastructure platform code to be compatible with both Exynos and
>>>> i.MX8M. This is the prime reason for adding that commit head and
>>>> explaining the same in the commit body.
>>>
>>> Diffstat looks like this:
>>>
>>>    drivers/gpu/drm/bridge/samsung-dsim.c   | 1703
>>> ++++++++++++++++++++++
>>>    drivers/gpu/drm/exynos/Kconfig          |    1 +
>>>    drivers/gpu/drm/exynos/exynos_drm_dsi.c | 1766
>>> ++---------------------
>>>    include/drm/bridge/samsung-dsim.h       |  113 ++
>>>    7 files changed, 1952 insertions(+), 1653 deletions(-)
>>>
>>> Looks to me like most of the code is just moved from existing driver in
>>> this patch.
>>
>> Yeah, as I explained (from commit) it is moved, updated, and written
>> the plat code. How about this head?
>>
>> "drm: bridge: Add Samsung DSIM bridge (Split from exynos_drm_dsi)"
>
> I disagree with the "Add" part of the Subject, but I'll wait for
> others' opinion here.

Maybe something like a "Generalize Exynos-DSI DRM driver into a generic
Samsung DSIM bridge"?

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland