Hi, Shawn.
On 01/14/2016 10:08 AM, Shawn Lin wrote:
> This patch implement hw_reset function for DesignWare
> MMC controller. By adding this feature, mmc blk can
> do some basic recovery.
>
> Set the following resets:
> software reset – BMOD[0] for IDMAC only
> DMA reset– CTRL[2]
> FIFO reset – CTRL[1] bits
>
> Program the CARD_RESET register with a value of 0 for the bit
> corresponding to the card number; This programming asserts the
> RST_n signal and resets the card. After a minimum of 1 μs, de-asserts the
> RST_n signal and takes the card out of reset. The application can program
> a new CMD only after a minimum of 200 us
>
> This implementation can be easily tested by cutting off->On vmmc
> while doing data accessing in background to simulate that case.
>
> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
>
> ---
>
> Changes in v3:
> - reset for each slot
> - simply the commit msg
>
> Changes in v2:
> - remove unecessary mb
> - reduce time cost for hw_reset
> - combine SDMMC_CTRL_DMA_RESET and SDMMC_CTRL_FIFO_RESET
>
> drivers/mmc/host/dw_mmc.c | 29 +++++++++++++++++++++++++++++
> drivers/mmc/host/dw_mmc.h | 3 +++
> 2 files changed, 32 insertions(+)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 7128351..fddbcb6 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1477,6 +1477,34 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
> return present;
> }
>
> +static void dw_mci_hw_reset(struct mmc_host *mmc)
> +{
> + struct dw_mci_slot *slot = mmc_priv(mmc);
> + struct dw_mci *host = slot->host;
> + int reset;
> +
> + if (host->use_dma == TRANS_MODE_IDMAC)
> + dw_mci_idmac_reset(host);
> +
> + if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET |
> + SDMMC_CTRL_FIFO_RESET))
> + return;
> +
> + /*
> + * According to eMMC spec, card reset procedure:
> + * tRstW >= 1us: RST_n pulse width
> + * tRSCA >= 200us: RST_n to Command time
> + * tRSTH >= 1us: RST_n high period
> + */
> + reset = mci_readl(host, RST_N);
> + reset &= ~(SDMMC_RST_HWACTIVE << slot->id);
> + mci_writel(slot->host, RST_N, reset);
I will pick this patch, after change "host" instead of "slot->host".
(I will change it when i apply this.)
Thanks!
Best Regards,
Jaehoon Chung
> + usleep_range(1, 2);
> + reset |= SDMMC_RST_HWACTIVE << slot->id;
> + mci_writel(slot->host, RST_N, reset);
> + usleep_range(200, 300);
> +}
> +
> static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
> {
> struct dw_mci_slot *slot = mmc_priv(mmc);
> @@ -1563,6 +1591,7 @@ static const struct mmc_host_ops dw_mci_ops = {
> .set_ios = dw_mci_set_ios,
> .get_ro = dw_mci_get_ro,
> .get_cd = dw_mci_get_cd,
> + .hw_reset = dw_mci_hw_reset,
> .enable_sdio_irq = dw_mci_enable_sdio_irq,
> .execute_tuning = dw_mci_execute_tuning,
> .card_busy = dw_mci_card_busy,
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index f695b58..a14b7fc 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -46,6 +46,7 @@
> #define SDMMC_VERID 0x06c
> #define SDMMC_HCON 0x070
> #define SDMMC_UHS_REG 0x074
> +#define SDMMC_RST_N 0x078
> #define SDMMC_BMOD 0x080
> #define SDMMC_PLDMND 0x084
> #define SDMMC_DBADDR 0x088
> @@ -169,6 +170,8 @@
> #define SDMMC_IDMAC_ENABLE BIT(7)
> #define SDMMC_IDMAC_FB BIT(1)
> #define SDMMC_IDMAC_SWRESET BIT(0)
> +/* H/W reset */
> +#define SDMMC_RST_HWACTIVE 0x1
> /* Version ID register define */
> #define SDMMC_GET_VERID(x) ((x) & 0xFFFF)
> /* Card read threshold */
>
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