[U-Boot] [PATCH V4 3/9] DWMMC: Initialise dwmci and resolve EMMC read write issues

[Jaehoon Chung]

On 01/11/2013 12:26 AM, Simon Glass wrote:
> Hi Amar,
> 
> On Fri, Jan 4, 2013 at 1:34 AM, Amar <amarendra.xt at samsung.com> wrote:
>> This patch enumerates dwmci and set auto stop command during
>> dwmci initialisation.
>> EMMC read/write is not happening in current implementation
>> due to improper fifo size computation. Hence Modified the fifo size
>> computation to resolve EMMC read write issues.
>>
>> Changes from V1:
>>         1)Created the macros RX_WMARK_SHIFT and RX_WMARK_MASK in header file.
>>
>> Changes from V2:
>>         1)Updation of commit message and resubmition of proper patch set.
>>
>> Changes from V3:
>>         1)Updated to use the macro DWMCI_CTRL_SEND_AS_CCSD instead of
>>         the hard coded value (1 << 10).
> 
> I suggest you take a look at patman which might simplify your patch
> sending and change logs - see tools/patman/README for details.
> 
>>
>> Signed-off-by: Amar <amarendra.xt at samsung.com>
>> ---
>>  drivers/mmc/dw_mmc.c | 14 ++++++++++++--
>>  1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
>> index 4070d4e..776fdb6 100644
>> --- a/drivers/mmc/dw_mmc.c
>> +++ b/drivers/mmc/dw_mmc.c
>> @@ -136,6 +136,7 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
>>                         return TIMEOUT;
>>                 }
>>                 timeout--;
>> +               mdelay(1);
> 
> How long will this delay in total?
i didn't sure why add the mdelay(1)..i think mdelay(1) is too long.
Isn't there other approach to resolve read/write issue?

Best Regards,
Jaehoon Chung
> 
>>         }
>>
>>         dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_ALL);
>> @@ -314,7 +315,7 @@ static void dwmci_set_ios(struct mmc *mmc)
>>  static int dwmci_init(struct mmc *mmc)
>>  {
>>         struct dwmci_host *host = (struct dwmci_host *)mmc->priv;
>> -       u32 fifo_size, fifoth_val;
>> +       u32 fifo_size, fifoth_val, ier;
>>
>>         dwmci_writel(host, DWMCI_PWREN, 1);
>>
>> @@ -323,6 +324,14 @@ static int dwmci_init(struct mmc *mmc)
>>                 return -1;
>>         }
>>
>> +       /* Enumerate at 400KHz */
>> +       dwmci_setup_bus(host, mmc->f_min);
>> +
>> +       /* Set auto stop command */
>> +       ier = dwmci_readl(host, DWMCI_CTRL);
>> +       ier |= DWMCI_CTRL_SEND_AS_CCSD;
>> +       dwmci_writel(host, DWMCI_CTRL, ier);
>> +
>>         dwmci_writel(host, DWMCI_RINTSTS, 0xFFFFFFFF);
>>         dwmci_writel(host, DWMCI_INTMASK, 0);
>>
>> @@ -332,10 +341,11 @@ static int dwmci_init(struct mmc *mmc)
>>         dwmci_writel(host, DWMCI_BMOD, 1);
>>
>>         fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
>> +       fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1;
>>         if (host->fifoth_val)
>>                 fifoth_val = host->fifoth_val;
>>         else
>> -               fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size/2 -1) |
>> +               fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size/2 - 1) |
>>                         TX_WMARK(fifo_size/2);
> 
> {} around this else I think. Also space around /
> 
>>         dwmci_writel(host, DWMCI_FIFOTH, fifoth_val);
>>
>> --
>> 1.8.0
>>
> 
> Regards,
> Simon
>