[PATCH 3/7] video: exynos_mipi_dsim: Use the generic PHY driver

Donghwa Lee dh09.lee at samsung.com
Tue Oct 29 04:38:42 EDT 2013

Hi Tomasz,
On Tue, OCT 28, 2013 21:24, Tomasz Figa wrote:
> Hi Donghwa,
> On Monday 28 of October 2013 15:12:08 Donghwa Lee wrote:
>> On Fri, OCT 25, 2013 06:57, Sylwester Nawrocki wrote:
>>> On 10/24/2013 05:57 PM, Kishon Vijay Abraham I wrote:
>>>> On Thursday 24 October 2013 09:12 PM, Sachin Kamat wrote:
>>>>> On 24 October 2013 20:00, Olof Johansson<olof at lixom.net>  wrote:
>>>>>> On Wed, Oct 16, 2013 at 9:28 AM, Kishon Vijay Abraham I<kishon at ti.com>  wrote:
>>>>>>> diff --git a/drivers/video/exynos/exynos_mipi_dsi.c b/drivers/video/exynos/exynos_mipi_dsi.c
>>>>>>> index 32e5406..00b3a52 100644
>>>>>>> --- a/drivers/video/exynos/exynos_mipi_dsi.c
>>>>>>> +++ b/drivers/video/exynos/exynos_mipi_dsi.c
>>>>>>> @@ -156,8 +157,7 @@ static int exynos_mipi_dsi_blank_mode(struct mipi_dsim_device *dsim, int power)
>>>>>>>                  exynos_mipi_regulator_enable(dsim);
>>>>>>>                  /* enable MIPI-DSI PHY. */
>>>>>>> -               if (dsim->pd->phy_enable)
>>>>>>> -                       dsim->pd->phy_enable(pdev, true);
>>>>>>> +               phy_power_on(dsim->phy);
>>>>>>>                  clk_enable(dsim->clock);
>>>>>> This introduces the below with exynos_defconfig:
>>>>>> ../../drivers/video/exynos/exynos_mipi_dsi.c: In function
>>>>>> 'exynos_mipi_dsi_blank_mode':
>>>>>> ../../drivers/video/exynos/exynos_mipi_dsi.c:144:26: warning: unused
>>>>>> variable 'pdev' [-Wunused-variable]
>>>>>>    struct platform_device *pdev = to_platform_device(dsim->dev);
>>> Sorry about missing that, I only noticed this warning recently and didn't
>>> get around to submit a patch.
>>>>> I have already submitted a patch to fix this [1]
>>> Thanks a lot guys for fixing this.
>>>>> [1] http://marc.info/?l=linux-fbdev&m=138233359617936&w=2
>>>> Sorry, missed that :-(
>>> This MIPI DSIM driver is affectively a dead code in the mainline now, once
>>> Exynos become a dt-only platform. I guess it can be deleted for 3.14, once
>>> S5P gets converted to the device tree. The new driver using CDF is basically
>>> a complete rewrite. Or device tree support should be added to that driver,
>>> but I believe it doesn't make sense without CDF.
>> MIPI DSIM driver is not a dead code. There is a steady trickle of patches.
>> It's kind of late, but, I will update it as DT based drivers as soon as possible.
>> And Why do you think that DT support of existing MIPI DSIM is something less
>> than great?
> First of all, the exynos_mipi_dsim driver has currently no users in
> mainline kernel, so it is essentially dead code. In addition, on
> a platform that is the primary candidate for using it, which is Exynos,
> there is no way to use it, due to no DT support.
As I mentioned above, patches are submitted sometimes and I will update
this driver as soon as possible to support DT.
> As for the driver itself, it is not really a great example of good code.
> It contains a hacks, like calling msleep() without any clear reason and
> also many coding style issues. I'd prefer to replace it with the new
> exynos-dsi driver rewritten completely in SRPOL, when CDF is finished.

Yes, I know this drivers had been changed about only minor issues and
it is not really good code style. And CDF is more good and light.
But discussion for CDF is still remaining a kind of requests. If it is merged
into linux kernel and many users use it, existing MIPI DSI drivers will be
replaced with the new drivers naturally, isn't it?
Until that, I and quite a few users will update and code re-factory for
this drivers to be more better.

Donghwa Lee
> Best regards,
> Tomasz

More information about the linux-arm-kernel mailing list