resend
On May 11, 2011, at 8:01 AM, Philip Rakity wrote:
>
> On May 11, 2011, at 2:19 AM, zhangfei gao wrote:
>
>> On Thu, May 5, 2011 at 2:49 AM, Arindam Nath <arindam.nath@xxxxxxx> wrote:
>>> eMMC chips do not use CMD11 when changing voltage. Add extra
>>> argument to call to indicate if CMD11 needs to be sent.
>>
>> mmc_set_signal_voltage or start_signal_voltage_switch may not support
>> emmc, not only cmd11, but also start_signal_voltage_switch is wrote
>> according to sd phys spec.
>
> the callback may go to a different driver then sdhci.c
>
>> JESD84-A441 A8.1 describes how to support dual voltage of emmc,
>> however it only support to 1.8v.
>> Still not find emmc card which could support 1.2v.
>
> eMMC
> vcc -- 3.3v then vccq can be 3.3 or 1.8 or 1.2v
> vcc -- 1.8v then vccq can be 1.8v or 1.2v
>
> 1.2 v vccq support is indicated in the CARD TYPE [196]
>
> a standard SD host controller does not support 1.2v vccq but folks could extend the standard.
>
> eMMC is not expected to be voltage switched. The expectation is the board designer will
> fix the voltages and no changes are needed.
>
> vccq is independent of vcc. see section 12.5.3.
>
>
>>
>>>
>>> Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
>>> Reviewed-by: Arindam Nath <arindam.nath@xxxxxxx>
>>> ---
>>> drivers/mmc/core/core.c | 4 ++--
>>> drivers/mmc/core/core.h | 3 ++-
>>> drivers/mmc/core/sd.c | 4 ++--
>>> 3 files changed, 6 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>>> index 78a9b51..74b4409 100644
>>> --- a/drivers/mmc/core/core.c
>>> +++ b/drivers/mmc/core/core.c
>>> @@ -942,7 +942,7 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
>>> return ocr;
>>> }
>>>
>>> -int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
>>> +int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, int cmd11)
>>> {
>>> struct mmc_command cmd;
>>> int err = 0;
>>> @@ -953,7 +953,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
>>> * Send CMD11 only if the request is to switch the card to
>>> * 1.8V signalling.
>>> */
>>> - if (signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
>>> + if ((signal_voltage != MMC_SIGNAL_VOLTAGE_330) && cmd11) {
>>> memset(&cmd, 0, sizeof(struct mmc_command));
>>>
>>> cmd.opcode = SD_SWITCH_VOLTAGE;
>>> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
>>> index 93f3397..3c11e17 100644
>>> --- a/drivers/mmc/core/core.h
>>> +++ b/drivers/mmc/core/core.h
>>> @@ -41,7 +41,8 @@ void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
>>> void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width,
>>> unsigned int ddr);
>>> u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
>>> -int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage);
>>> +int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
>>> + int cmd11);
>>> void mmc_set_timing(struct mmc_host *host, unsigned int timing);
>>> void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
>>>
>>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
>>> index 851c8fc..d2a05ab 100644
>>> --- a/drivers/mmc/core/sd.c
>>> +++ b/drivers/mmc/core/sd.c
>>> @@ -731,7 +731,7 @@ try_again:
>>> */
>>> if (!mmc_host_is_spi(host) && rocr &&
>>> ((*rocr & 0x41000000) == 0x41000000)) {
>>> - err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
>>> + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, 1);
>>> if (err) {
>>> ocr &= ~SD_OCR_S18R;
>>> goto try_again;
>>> @@ -1104,7 +1104,7 @@ int mmc_attach_sd(struct mmc_host *host)
>>> WARN_ON(!host->claimed);
>>>
>>> /* Make sure we are at 3.3V signalling voltage */
>>> - err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330);
>>> + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
>>> if (err)
>>> return err;
>>>
>>> --
>>> 1.7.1
>>>
>>>
>
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