Hi Jaehoon,

On Thursday, August 23, 2012, Jaehoon Chung <jh80.ch...@samsung.com> wrote:
> To avoid glitches in the card clock output,
> need to check whether card is busy or not.
Could you describe the problem more?
In which situation did you meet this?

Thanks,
Seungwon Jeon
> 
> Signed-off-by: Jaehoon Chung <jh80.ch...@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
> ---
>  drivers/mmc/host/dw_mmc.c |   30 ++++++++++++++++++++++++------
>  drivers/mmc/host/dw_mmc.h |    1 +
>  2 files changed, 25 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 36f98c0..8bef3c2 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 
> cmd, u32 arg)
>               cmd, arg, cmd_status);
>  }
> 
> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
> +{
> +     struct dw_mci *host = slot->host;
> +     unsigned long timeout = jiffies + msecs_to_jiffies(500);
> +     u32 ctrl, status;
> +
> +     do {
> +             status = mci_readl(host, STATUS);
> +             if (!(status & SDMMC_DATA_BUSY))
> +                     break;
> +             ctrl = mci_readl(host, CTRL);
> +             ctrl |= SDMMC_CTRL_RESET;
> +             mci_writel(host, CTRL, ctrl);
> +     } while (time_before(jiffies, timeout));
> +
> +     if (status & SDMMC_DATA_BUSY)
> +             dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
> +
> +     mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +}
> +
>  static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>  {
>       struct dw_mci *host = slot->host;
> @@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>               mci_writel(host, CLKSRC, 0);
> 
>               /* inform CIU */
> -             mci_send_cmd(slot,
> -                          SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +             dw_mci_inform_ciu(slot);
> 
>               /* set clock to desired speed */
>               mci_writel(host, CLKDIV, div);
> 
>               /* inform CIU */
> -             mci_send_cmd(slot,
> -                          SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +             dw_mci_inform_ciu(slot);
> 
>               /* enable clock; only low power if no SDIO */
>               clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
> @@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>               mci_writel(host, CLKENA, clk_en_a);
> 
>               /* inform CIU */
> -             mci_send_cmd(slot,
> -                          SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +             dw_mci_inform_ciu(slot);
> 
>               host->current_speed = slot->clock;
>       }
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index 15c27e1..b6a1a78 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -127,6 +127,7 @@
>  #define SDMMC_CMD_INDX(n)            ((n) & 0x1F)
>  /* Status register defines */
>  #define SDMMC_GET_FCNT(x)            (((x)>>17) & 0x1FFF)
> +#define SDMMC_DATA_BUSY                      BIT(9)
>  /* Internal DMAC interrupt defines */
>  #define SDMMC_IDMAC_INT_AI           BIT(9)
>  #define SDMMC_IDMAC_INT_NI           BIT(8)
> --
> 1.7.4.1
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to