[U-Boot] [PATCH V3 3/9] DWMMC: Initialise dwmci and resolve EMMC read write issues

Jaehoon Chung
2013-01-02T05:12:21Z

On 12/31/2012 07:58 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.
What issue for read/write?
>
> 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.
>
> Signed-off-by: Amar <amarendra.xt@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..d8fa1a2 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);
Why add the mdelay(1)? Could you explain to me?
> }
>
> 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 |= (1<<10);
Use the define..ex) define DWMCI_CTRL_AUTO_STOP_CMD BIT(10)
> + dwmci_writel(host, DWMCI_CTRL, ier);
If set to auto stop command, then you didn't see any problem?

Best Regards,
Jaehoon Chung
> +
> 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);
> dwmci_writel(host, DWMCI_FIFOTH, fifoth_val);
>
>