[U-Boot] [RFC 2/3][v4] mmc: SEND_OP_COND considers card capabilities (voltage)

[Raffaele Recalcati]

Hi Andy,

On Wed, Apr 13, 2011 at 1:24 PM, Andy Fleming <afleming at gmail.com> wrote:
> On Fri, Mar 11, 2011 at 6:01 AM, Raffaele Recalcati
> <lamiaposta71 at gmail.com> wrote:
>> From: Raffaele Recalcati <raffaele.recalcati at bticino.it>
>>
>> The first SEND_OP_COND (CMD1) command added is used to ask card capabilities.
>> After it an AND operation is done between card capabilities and host
>> capabilities (at the moment only for the voltage field).
>> Finally the correct value is sent to the MMC, waiting that the card
>> exits from busy state.
>>
>> Signed-off-by: Raffaele Recalcati <raffaele.recalcati at bticino.it>
>> ---
>>  drivers/mmc/mmc.c |   19 +++++++++++++++++--
>>  include/mmc.h     |    2 ++
>>  2 files changed, 19 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
>> index fc1792a..5bea476 100644
>> --- a/drivers/mmc/mmc.c
>> +++ b/drivers/mmc/mmc.c
>> @@ -351,17 +351,32 @@ sd_send_op_cond(struct mmc *mmc)
>>
>>  int mmc_send_op_cond(struct mmc *mmc)
>>  {
>> -       int timeout = 1000;
>> +       int timeout = 10000;
>>        struct mmc_cmd cmd;
>>        int err;
>>
>>        /* Some cards seem to need this */
>>        mmc_go_idle(mmc);
>>
>> +       /* Asking to the card its capabilities */
>> +       cmd.cmdidx = MMC_CMD_SEND_OP_COND;
>> +       cmd.resp_type = MMC_RSP_R3;
>> +       cmd.cmdarg = 0;
>> +       cmd.flags = 0;
>> +
>> +       err = mmc_send_cmd(mmc, &cmd, NULL);
>> +
>> +       if (err)
>> +               return err;
>> +
>> +       udelay(1000);
>> +
>>        do {
>>                cmd.cmdidx = MMC_CMD_SEND_OP_COND;
>>                cmd.resp_type = MMC_RSP_R3;
>> -               cmd.cmdarg = OCR_HCS | mmc->voltages;
>> +               cmd.cmdarg = ((mmc->voltages &
>> +                             (cmd.response[0] & OCR_VOLTAGE_MASK)) |
>> +                             (cmd.response[0] & OCR_ACCESS_MODE));
>
>
> My concern here is that OCR_HCS has been dropped. I thought it was
> necessary to query the HCS abilities.
>
> I'm guessing I'm missing something, or that it's not needed, so I will
> apply this patch, and we'll see if anyone has issues.
>
> Andy
>

Thx,
Raffaele