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| author | Shawn Lin <shawn.lin@rock-chips.com> | 2016-01-14 09:08:02 +0800 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2016-02-29 11:03:09 +0100 |
| commit | 935a665e15dcda3b0b986829f32e2724db1f20fc (patch) | |
| tree | 523bcaa8f8c40a11922e32b20ebac44052ff0b89 /drivers/mmc | |
| parent | aaaaeb7a933471f6413ca44dd36efd57f2fa9429 (diff) | |
| download | op-kernel-dev-935a665e15dcda3b0b986829f32e2724db1f20fc.zip op-kernel-dev-935a665e15dcda3b0b986829f32e2724db1f20fc.tar.gz | |
mmc: dw_mmc: add hw_reset support
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 ?s, 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@rock-chips.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/dw_mmc.c | 29 | ||||
| -rw-r--r-- | drivers/mmc/host/dw_mmc.h | 3 |
2 files changed, 32 insertions, 0 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 7d6bd9d..6ad9ebf 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1474,6 +1474,34 @@ 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(host, RST_N, reset); + usleep_range(1, 2); + reset |= SDMMC_RST_HWACTIVE << slot->id; + mci_writel(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); @@ -1560,6 +1588,7 @@ 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 6fc84b6..68d5da2 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 */ |
