[U-Boot] [PATCH V8 3/9] DWMMC: Initialise dwmci and resolve EMMC read write issues

[Amarendra Reddy]

Hi Jaehoon,

Auto-stop command is not related to read/write issue.
Today, I commented the 'auto-stop command' enable code and tested, SD/EMMC
read write and EMMC boot work fine.
Hence enabling Auto-stop command is not required.
I shall update the same in next patchset.

Thanks & Regards
Amarendra Reddy

On 9 April 2013 16:19, Jaehoon Chung <jh80.chung at samsung.com> wrote:

> Hi Amar,
>
> I'm not sure that need to enable the auto-stop command feature.
> why do you enable this feature? Is there any benefit?
> Is it related with read/write issue?
>
> Best Regards,
> Jaehoon Chung
>
> On 04/03/2013 11:08 PM, Amar 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.
> >
> > Signed-off-by: Amar <amarendra.xt at samsung.com>
> > ---
> > Changes since V1:
> >       1)Created the macros RX_WMARK_SHIFT and RX_WMARK_MASK in header
> file.
> >
> > Changes since V2:
> >       1)Updation of commit message and resubmition of proper patch set.
> >
> > Changes since V3:
> >       1)Updated to use the macro DWMCI_CTRL_SEND_AS_CCSD instead of
> >       the hard coded value (1 << 10).
> >
> > Changes since V4:
> >       1)Updated the function dwmci_send_cmd() to use get_timer() instead
> >       of using mdelay(1).
> >
> > Changes since V5:
> >       1)Updated in response to review comments.
> >
> > Changes since V6:
> >       No change.
> >
> > Changes since V7:
> >       1)Updated the function dwmci_setup_bus() to return 0 if (freq ==
> 0).
> >       This is to avoid the run time exception "raise:Signal # 8 caught".
> >
> >  drivers/mmc/dw_mmc.c | 28 ++++++++++++++++++----------
> >  1 file changed, 18 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
> > index 4070d4e..963a515 100644
> > --- a/drivers/mmc/dw_mmc.c
> > +++ b/drivers/mmc/dw_mmc.c
> > @@ -129,13 +129,13 @@ static int dwmci_send_cmd(struct mmc *mmc, struct
> mmc_cmd *cmd,
> >       unsigned int timeout = 100000;
> >       u32 retry = 10000;
> >       u32 mask, ctrl;
> > +     ulong start = get_timer(0);
> >
> >       while (dwmci_readl(host, DWMCI_STATUS) & DWMCI_BUSY) {
> > -             if (timeout == 0) {
> > +             if (get_timer(start) > timeout) {
> >                       printf("Timeout on data busy\n");
> >                       return TIMEOUT;
> >               }
> > -             timeout--;
> >       }
> >
> >       dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_ALL);
> > @@ -143,7 +143,6 @@ static int dwmci_send_cmd(struct mmc *mmc, struct
> mmc_cmd *cmd,
> >       if (data)
> >               dwmci_prepare_data(host, data);
> >
> > -
> >       dwmci_writel(host, DWMCI_CMDARG, cmd->cmdarg);
> >
> >       if (data)
> > @@ -231,9 +230,8 @@ static int dwmci_setup_bus(struct dwmci_host *host,
> u32 freq)
> >       int timeout = 10000;
> >       unsigned long sclk;
> >
> > -     if (freq == host->clock)
> > +     if ((freq == host->clock) || (freq == 0))
> >               return 0;
> > -
> >       /*
> >        * If host->mmc_clk didn't define,
> >        * then assume that host->bus_hz is source clock value.
> > @@ -314,7 +312,7 @@ 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 +321,14 @@ 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);
> >
> > @@ -332,11 +338,13 @@ static int dwmci_init(struct mmc *mmc)
> >       dwmci_writel(host, DWMCI_BMOD, 1);
> >
> >       fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
> > -     if (host->fifoth_val)
> > +     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) |
> > -                     TX_WMARK(fifo_size/2);
> > +     } else {
> > +             fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size / 2 - 1) |
> > +                     TX_WMARK(fifo_size / 2);
> > +     }
> >       dwmci_writel(host, DWMCI_FIFOTH, fifoth_val);
> >
> >       dwmci_writel(host, DWMCI_CLKENA, 0);
> >
>
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