mmc: mediatek: add implement of ops->hw_reset()

add implement of ops->hw_reset() for eMMC

Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 385816375614..562764430881 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -64,6 +64,7 @@
 #define SDC_RESP2        0x48
 #define SDC_RESP3        0x4c
 #define SDC_BLK_NUM      0x50
+#define EMMC_IOCON       0x7c
 #define SDC_ACMD_RESP    0x80
 #define MSDC_DMA_SA      0x90
 #define MSDC_DMA_CTRL    0x98
@@ -1209,6 +1210,15 @@ end:
         pm_runtime_put_autosuspend(host->dev);
 }
 
+static void msdc_hw_reset(struct mmc_host *mmc)
+{
+        struct msdc_host *host = mmc_priv(mmc);
+
+        sdr_set_bits(host->base + EMMC_IOCON, 1);
+        udelay(10); /* 10us is enough */
+        sdr_clr_bits(host->base + EMMC_IOCON, 1);
+}
+
 static struct mmc_host_ops mt_msdc_ops = {
         .post_req = msdc_post_req,
         .pre_req = msdc_pre_req,
@@ -1216,6 +1226,7 @@ static struct mmc_host_ops mt_msdc_ops = {
         .set_ios = msdc_ops_set_ios,
         .start_signal_voltage_switch = msdc_ops_switch_volt,
         .card_busy = msdc_card_busy,
+        .hw_reset = msdc_hw_reset,
 };
 
 static int msdc_drv_probe(struct platform_device *pdev)