Re: [PATCH v3] mmc: dw_mmc: Add MSHC compatible for Exynos4412

[Dongjin Kim <tobetter@gmail.com>]

Hello Seungwon,

OK, I will change the commit message. And I also think Alim's idea is
good but need more detail about functional features of Synopsis' IP.
Similar situation would be happened to Exynos4210 which is not
supported by dw_mmc-exynos.c yet.

Regards,
Dongjin.

On Thu, Feb 21, 2013 at 7:53 PM, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> On Wednesday, February 20, 2013, Alim Akhtar wrote:
>> Hi,
>>
>> On Tue, Feb 19, 2013 at 6:04 PM, Dongjin Kim <tobetter@gmail.com> wrote:
>> > Hello Seungwon,
>> >
>> > Thank you for reviewing and I understand what you mean.
>> >
>> > I agree that Exynos5250 and Exynos4412 are not same, no idea how much
>> > they are different because no Exynos5250 spec on my hand. But at least
>> > I assumed that the capabilities below are supported by Exynos4412 in
>> > terms of its datasheet and it does work on my end as expected. :) Also
>> > I assumed it will be separated if one of both become different to add
>> > more capabilities.
>> >
>> >         MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
>> >                MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
>> >
>> > Maybe my understanding or approach is wrong since I do not have the
>> > information of Exynos5250.
>> > And suggestion do you have?
> At least, these capabilities can be shared because of common feature, not fully same.
> Dongjin, could you modify the commit message and comments of code?
>
> Let me introduce the functional feature of Exynos5250 and capability extension.
> I guess I'll send soon.
>
> Thanks,
> Seungwon Jeon
>
>>
>> Recently Guennadi Liakhovetski has done some work to centralize the
>> mmc capabilities. See [1] and [2].
>> Those patches are pushed to Chris's mmc-next tree.
>> Is  it possible to extend [1] and [2] and add more capabilities (at
>> least all known one) and let these caps being passed from DT instead?
>>
>> Second thought is, let the common minimum caps as a part of .caps
>> field in dw_mmc-exynos.c itself and pass the extra/advance controller
>> caps from DT and parse them via dw_mci_parse_dt() in dw_mmc.c itself.
>>
>> [1] https://patchwork.kernel.org/patch/1991851/
>> [2] https://patchwork.kernel.org/patch/2106531/
>>
>> > Regards,
>> > Dongjin.
>> >
>> > On Tue, Feb 19, 2013 at 7:19 PM, Seungwon Jeon <tgih.jun@samsung.com> wrote:
>> >> On Tuesday, February 19, 2013, Dongjin Kim wrote:
>> >>> This patch adds the compatible string for MSHC controller of Exynos4412, and
>> >>> share the controller specific properties with Exynos5250 since they have same
>> >>> features. Its driver data name is changed to exynos_drv_data instead SoC
>> >>> specific name.
>> >>
>> >> It's not actually same.
>> >> Exynos4412 doesn't have forward compatibilities for Exynos5250.
>> >> I agree that functionality of exynos_drv_data is common.
>> >> These functions have been implemented for existing Exynos*.
>> >> But in case of caps, it can't applied completely.
>> >> I'm concerning about this.
>> >>
>> >> Thanks,
>> >> Seungwon Jeon
>> >>>
>> >>> Cc: Jaehoon Chung <jh80.chung@samsung.com>
>> >>> Cc: Sachin Kamat <sachin.kamat@linaro.org>
>> >>> Signed-off-by: Dongjin Kim <tobetter@gmail.com>
>> >>> ---
>> >>>  drivers/mmc/host/dw_mmc-exynos.c |   12 +++++++-----
>> >>>  1 file changed, 7 insertions(+), 5 deletions(-)
>> >>>
>> >>> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
>> >>> index 4d50da6..38cd03c 100644
>> >>> --- a/drivers/mmc/host/dw_mmc-exynos.c
>> >>> +++ b/drivers/mmc/host/dw_mmc-exynos.c
>> >>> @@ -199,8 +199,8 @@ static int dw_mci_exynos_setup_bus(struct dw_mci *host,
>> >>>       return 0;
>> >>>  }
>> >>>
>> >>> -/* Exynos5250 controller specific capabilities */
>> >>> -static unsigned long exynos5250_dwmmc_caps[4] = {
>> >>> +/* Exynos4412/Exynos5250 controller specific capabilities */
>> >>> +static unsigned long exynos_dwmmc_caps[4] = {
>> >>>       MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
>> >>>               MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
>> >>>       MMC_CAP_CMD23,
>> >>> @@ -208,8 +208,8 @@ static unsigned long exynos5250_dwmmc_caps[4] = {
>> >>>       MMC_CAP_CMD23,
>> >>>  };
>> >>>
>> >>> -static const struct dw_mci_drv_data exynos5250_drv_data = {
>> >>> -     .caps                   = exynos5250_dwmmc_caps,
>> >>> +static const struct dw_mci_drv_data exynos_drv_data = {
>> >>> +     .caps                   = exynos_dwmmc_caps,
>> >>>       .init                   = dw_mci_exynos_priv_init,
>> >>>       .setup_clock            = dw_mci_exynos_setup_clock,
>> >>>       .prepare_command        = dw_mci_exynos_prepare_command,
>> >>> @@ -219,8 +219,10 @@ static const struct dw_mci_drv_data exynos5250_drv_data = {
>> >>>  };
>> >>>
>> >>>  static const struct of_device_id dw_mci_exynos_match[] = {
>> >>> +     { .compatible = "samsung,exynos4412-dw-mshc",
>> >>> +                     .data = &exynos_drv_data, },
>> >>>       { .compatible = "samsung,exynos5250-dw-mshc",
>> >>> -                     .data = &exynos5250_drv_data, },
>> >>> +                     .data = &exynos_drv_data, },
>> >>>       {},
>> >>>  };
>> >>>  MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
>> >>> --
>> >>> 1.7.10.4
>> >>>
>> >>> --
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>> >>
>> > --
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>> --
>> Regards,
>> Alim
>> --
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