On 1/18/12, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> 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.
current sdhci ocr_avail is 0x300080 and wanted ocr is 0x10000 so it
doesn't support it.
[ 0.984754] sdhci_add_host[2888] ocr_avail 0x300080
[ 0.989909] sdhci_add_host[2889] host->ocr_avail_mmc 0x10000
Thank you,
Kyungmin Park
>
>>>
>>>>> - 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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