Re: [PATCH 5/5] mmc: dw-mmc: add the use_hold_reg in CMD register

[Jaehoon Chung <jh80.chung@samsung.com>]

On 08/23/2012 09:41 PM, Will Newton wrote:
> On Thu, Aug 23, 2012 at 12:31 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> This patch is added the use_hold_reg bit in CMD register.
>>
>> In upper version than 2.40a, bit[29] of CMD register is used the use_hold_reg.
>> Some SoC is affected by this bit.
>> (This bit means whether use hold register when send data and cmd.
>>  And related with cclk_in_drv phase)
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>  drivers/mmc/host/dw_mmc.c  |   36 ++++++++++++++++++++++++++++++++++++
>>  drivers/mmc/host/dw_mmc.h  |    1 +
>>  include/linux/mmc/dw_mmc.h |    3 +++
>>  3 files changed, 40 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index feafa2d..426171f 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -265,11 +265,45 @@ static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
>>  static void dw_mci_start_command(struct dw_mci *host,
>>                                  struct mmc_command *cmd, u32 cmd_flags)
>>  {
>> +       struct dw_mci_slot *slot = host->cur_slot;
>> +       struct mmc_ios *ios = &slot->mmc->ios;
>> +
>>         host->cmd = cmd;
>>         dev_vdbg(&host->dev,
>>                  "start command: ARGR=0x%08x CMDR=0x%08x\n",
>>                  cmd->arg, cmd_flags);
>>
>> +       if (host->quirks & DW_MCI_QUIRK_USE_CLKSEL_REG) {
>> +               /*
>> +                * If use HOLD register and SDR12/SDSR25,
>> +                * CMD and DATA sent to card through HOLD register by default.
>> +                * But if mode is SDR50/DDR50/SDR104,
>> +                * only use the hold register when cclk_in_drv value is upper than 0.
> 
> "greater" might be better than "upper" here.
will change.
> 
>> +                */
>> +               switch (ios->timing) {
>> +               case MMC_TIMING_UHS_SDR50:
>> +               case MMC_TIMING_UHS_DDR50:
>> +                       if (host->pdata->get_clk_drv)
>> +                               if ((host->pdata->get_clk_drv(host) &&
>> +                                               host->use_hold_reg)) {
> 
> There's more brackets than necessary here in the second if, and the
> two if conditions could probably be combined to make it neater.
Ok. I will fix.

Best Regards,
Jaehoon Chung
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