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

[Girish K S <girish.shivananjappa@linaro.org>]

On 26 July 2012 11:30, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> Hi Girish,
>
> I re-tested the your patch.
> How about locating into dw_mci_setup_bus()?
>
> And if compare the previously and current busmode,
> I think host needs not to re-write at register.
> For example,
> if (slot->bus_mode == ios->bus_mode)
>         return;
>
> Then this patch looks good to me.
Thanks Jaehoon. I will try to test the same and let you know. if
relocation is fine then i will send a patch
>
> Best Regards,
> Jaehoon Chung
>
> On 07/26/2012 12:41 PM, Girish K S wrote:
>> On 24 July 2012 18:37, Jae hoon Chung <jh80.chung@gmail.com> wrote:
>>> 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() .
>> Sure. Currently i am setting the bus mode after sending the command
>> during the clock setting. since the bus mode has affect on the cmd
>> line i will try to move the location of calling bus mode before
>> setting the clock.
>> you can just check whether card gets detected by moving the set mode
>> function just below the switch statement of bus width.
>> On my board irrespective of the set bus mode location it works fine
>>>
>>> Best Regards,
>>> Jaehoon Chung
>>>
>>> 2012/7/24 Girish K S <girish.shivananjappa@linaro.org>:
>>>> On 24 July 2012 17:06, Girish K S <girish.shivananjappa@linaro.org> wrote:
>>>>> On 24 July 2012 16:39, Jaehoon Chung <jh80.chung@samsung.com> 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@linaro.org>
>>>>>>> ---
>>>>>>>  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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>>
>
>