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

[Seungwon Jeon <tgih.jun@samsung.com>]

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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