Re: [PATCH v4 9/9] mmc: dw_mmc: add support for exynos specific implementation of dw-mshc

[Jaehoon Chung <jh80.chung@samsung.com>]

On 08/28/2012 02:10 PM, Thomas Abraham wrote:
> On 28 August 2012 10:40, Thomas Abraham <thomas.abraham@linaro.org> wrote:
>> On 28 August 2012 10:25, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>> Hi Thomas,
>>>
>>> On 08/28/2012 01:48 PM, Thomas Abraham wrote:
>>>> On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>>> Hi Thomas,
>>>>>
>>>>>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>>>>>> +     if (gpio_is_valid(gpio)) {
>>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>>>>>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>>>>>> +                                             gpio);
>>>>>> +     } else {
>>>>>> +             dev_info(host->dev, "wp gpio not available");
>>>>>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>>>>>> +     }
>>>>>> +
>>>>>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>>>>> +             return 0;
>>>>>> +
>>>>>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>>>>>> +     if (gpio_is_valid(gpio)) {
>>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
>>>>> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
>>>>> Can we use this? i think we can use them.
>>>>> Just my opinion.
>>>>
>>>> Thanks for letting me know about this, I was not aware of this.
>>>> Looking into this code, it is usable for controllers that use a gpio
>>>> (specified using cd-gpios property) as card-detect line. As you know,
>>>> the dw-mmc driver does not support this feature yet. In case of
>>>> exynos, the card-detect pin of the mmc slot is connected to the
>>>> card-detect pad of the dw-mmc controller using pinmux, which is not
>>>> considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
>>>> in this case.
>>> But In case of external card-detect-pin, we can use the mmc_gpio_request_cd().
>>
>> Yes, we can use. But the current dw-mmc controller driver does not
>> support this feature yet. The existing driver considers that (a)
>> card-detect line is connected to the card-detect pad of the controller
>> or (b) it is broken. For Exynos5250, it is case (a). There is no
> 
> Sorry, I meant smdk5250, not Exynos5250.
Already i tested with my exynos5 board.
If you want, i will share the patch.

Best Regards,
Jaehoon Chung
> 
>> support for using a gpio as an card-detect line.
>>
>> Thanks,
>> Thomas.
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