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?
- is it supplying VCC or VCCQ?
- what is the contents of the OCR register?
> 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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