On 18/01/12 01:58, Kyungmin Park wrote:
> On 1/17/12, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>> On 17/01/12 11:53, Kyungmin Park wrote:
>>> On 1/17/12, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>>>> On 17/01/12 11:05, Kyungmin Park wrote:
>>>>> On 1/17/12, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>>>>>> On 16/01/12 10:49, Jaehoon Chung wrote:
>>>>>>> This patch is added the MMC_CAP2_BROKEN_VOLTAGE.
>>>>>>>
>>>>>>> if the voltage didn't satisfy between min_uV and max_uV,
>>>>>>
>>>>>> Why is the fixed voltage not in the acceptable range for the card?
>>>>>> Doesn't that risk breaking the card?
>>>>> Hi Adrian,
>>>>>
>>>>> I don't know, they uses the not supported voltage. but it's worked
>>>>> properly for long time.
>>>>
>>>> I wonder if there is a generic problem here that this fix hides.
>>>> It would be nice to have an explanation. Do you know:
>>>> - what is the fixed voltage?
>>> Now 2.8V is supplied by gpio so make it fixed regulator
>>>> - is it supplying VCC or VCCQ?
>>> VDD in our schematic.
>>
>> Is it the NAND core voltage or the I/O voltage?
> In case of eMMC v4.41, it uses the same voltage, VDD is used for MMC
> I/O block and controller and another VDDF is used for flash.
It seems to me you just need to override the value of mmc->ocr_avail_mmc
calculated in sdhci_add_host() in sdhci.c to reflect the fact that the only
voltage available is 2.8V.
>>
>>>> - what is the contents of the OCR register?
>>> In sdhci_set_power(). it returns SDHCI_POWER_180, SDHCI_POWER_300, and
>>> SDHCI_POWER_330.
>>> In probe time, it return the SDHCI_POWER_330, and but fixed regulator
>>> returns the 2.8V so it calls regulator_set_voltage. and return -EINVAL
>>> since it's fixed regulator.
>>>
>>> Of course we can make workaround, set fixed regulator voltage as 3.3V.
>>> Even though actual voltage is 2.8V. so it's ambiguous.
>>>
>>> that's reason introduces the new quirk.
>>>
>>> Thank you,
>>> Kyungmin Park
>>>>
>>>>> Galaxy S2 also uses the same voltage as ours.
>>>>>
>>>>> I also think the modify the regulator framework to support voltage
>>>>> change at fixed regulator. but it's not good idea and doesn't match
>>>>> the regulator concept. so modify the sdhci codes to support our
>>>>> boards.
>>>>>
>>>>> Thank you,
>>>>> Kyungmin Park
>>>>>>
>>>>>>> try to change the voltage in core.c.
>>>>>>> When change the voltage, maybe use the regulator_set_voltage().
>>>>>>>
>>>>>>> In regulator_set_voltage(), check the below condition.
>>>>>>>
>>>>>>> /* sanity check */
>>>>>>> if (!rdev->desc->ops->set_voltage &&
>>>>>>> !rdev->desc->ops->set_voltage_sel) {
>>>>>>> ret = -EINVAL;
>>>>>>> goto out;
>>>>>>> }
>>>>>>>
>>>>>>> If Some-board should use the fixed-regulator, always return -EINVAL.
>>>>>>> Then, eMMC didn't initialize always.
>>>>>>>
>>>>>>> So if use the fixed-regulator or etc, we need to add the
>>>>>>> MMC_CAP2_BROKEN_VOLTAGE.
>>>>>>>
>>>>>>> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
>>>>>>> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
>>>>>>> ---
>>>>>>> drivers/mmc/core/core.c | 4 ++++
>>>>>>> include/linux/mmc/host.h | 1 +
>>>>>>> 2 files changed, 5 insertions(+), 0 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>>>>>>> index bec0bf2..6848789 100644
>>>>>>> --- a/drivers/mmc/core/core.c
>>>>>>> +++ b/drivers/mmc/core/core.c
>>>>>>> @@ -1121,6 +1121,10 @@ int mmc_regulator_set_ocr(struct mmc_host *mmc,
>>>>>>> * might not allow this operation
>>>>>>> */
>>>>>>> voltage = regulator_get_voltage(supply);
>>>>>>> +
>>>>>>> + if (mmc->caps2 & MMC_CAP2_BROKEN_VOLTAGE)
>>>>>>> + min_uV = max_uV = voltage;
>>>>>>> +
>>>>>>> if (voltage < 0)
>>>>>>> result = voltage;
>>>>>>> else if (voltage < min_uV || voltage > max_uV)
>>>>>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>>>>>>> index dd13e05..5659aee 100644
>>>>>>> --- a/include/linux/mmc/host.h
>>>>>>> +++ b/include/linux/mmc/host.h
>>>>>>> @@ -257,6 +257,7 @@ struct mmc_host {
>>>>>>> #define MMC_CAP2_HS200_1_2V_SDR (1 << 6) /* can support */
>>>>>>> #define MMC_CAP2_HS200 (MMC_CAP2_HS200_1_8V_SDR | \
>>>>>>> MMC_CAP2_HS200_1_2V_SDR)
>>>>>>> +#define MMC_CAP2_BROKEN_VOLTAGE (1 << 7) /* Use the broken voltage */
>>>>>>>
>>>>>>> mmc_pm_flag_t pm_caps; /* supported pm features */
>>>>>>> unsigned int power_notify_type;
>>>>>>> --
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>>>>>
>>>>
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>>
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