Re: [PATCH] mmc: dw_mmc: add busmode selection support

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Hi Girish,

Right, it be mentioned about the open-drain mode in synopsys spec.
But if didn't work on other board, there is some problem.
We can consider the location of set_busmode() .

Best Regards,
Jaehoon Chung

2012/7/24 Girish K S <girish.shivananjappa@xxxxxxxxxx>:
> On 24 July 2012 17:06, Girish K S <girish.shivananjappa@xxxxxxxxxx> wrote:
>> On 24 July 2012 16:39, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
>>> Hi Girish,
>>>
>>> Well..just tested on my board.
>>> this patch didn't work.(eMMC card didn't initialize)
>>> meaning of ios->bus_mode and synosys's bus_mode is same?
> Yes it is same. synopsys spec says this is specific to MMC
> initialization. when the card core sets this mode during
> initialization. the host has to set this bit
>>> How did you test this patch?
>> Tested it on exynos5 board using dt patches of thomas (with some
>> modification to his patch)
>>>
>>> Best Regards,
>>> Jaehoon Chung
>>>
>>> On 07/23/2012 08:16 PM, Girish K S wrote:
>>>> Synopsis Designware host controller has suppport for open
>>>> drain mode selection. During the mmc card initialization the
>>>> host controller can select the open-drain bit to allow the device
>>>> initialization in the open-drain mode. Once the device enters
>>>> the standby mode this bit can be reset to enter push-pull mode.
>>>>
>>>> Signed-off-by: Girish K S <girish.shivananjappa@xxxxxxxxxx>
>>>> ---
>>>>  drivers/mmc/host/dw_mmc.c |   14 ++++++++++++++
>>>>  drivers/mmc/host/dw_mmc.h |    1 +
>>>>  2 files changed, 15 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index 72dc3cd..da11e5a 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -773,6 +773,18 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>>>>       spin_unlock_bh(&host->lock);
>>>>  }
>>>>
>>>> +static void dw_mci_set_busmode(struct dw_mci_slot *slot)
>>>> +{
>>>> +     struct mmc_ios *ios = &slot->mmc->ios;
>>>> +     u32 reg;
>>>> +
>>>> +     reg = mci_readl(slot->host, CTRL);
>>>> +     if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
>>>> +             mci_writel(slot->host, CTRL, reg | SDMMC_CTRL_ENABLE_OD);
>>>> +     else
>>>> +             mci_writel(slot->host, CTRL, reg & ~SDMMC_CTRL_ENABLE_OD);
>>>> +}
>>>> +
>>>>  static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>>>  {
>>>>       struct dw_mci_slot *slot = mmc_priv(mmc);
>>>> @@ -818,6 +830,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>>>       default:
>>>>               break;
>>>>       }
>>>> +
>>>> +     dw_mci_set_busmode(slot);
>>>>  }
>>>>
>>>>  static int dw_mci_get_ro(struct mmc_host *mmc)
>>>> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
>>>> index 15c27e1..1a53fb2 100644
>>>> --- a/drivers/mmc/host/dw_mmc.h
>>>> +++ b/drivers/mmc/host/dw_mmc.h
>>>> @@ -67,6 +67,7 @@
>>>>
>>>>  /* Control register defines */
>>>>  #define SDMMC_CTRL_USE_IDMAC         BIT(25)
>>>> +#define SDMMC_CTRL_ENABLE_OD         BIT(24)
>>>>  #define SDMMC_CTRL_CEATA_INT_EN              BIT(11)
>>>>  #define SDMMC_CTRL_SEND_AS_CCSD              BIT(10)
>>>>  #define SDMMC_CTRL_SEND_CCSD         BIT(9)
>>>>
>>>
>>>
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