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* [PATCH 2/3] mmc: dw_mmc: add the card write threshold for HS400 mode
@ 2016-06-20  4:25 Jaehoon Chung
  2016-06-20  8:21 ` Shawn Lin
  0 siblings, 1 reply; 3+ messages in thread
From: Jaehoon Chung @ 2016-06-20  4:25 UTC (permalink / raw)
  To: linux-mmc; +Cc: ulf.hansson, shawn.lin, Jaehoon Chung

Since v2.80a, dwmmc controller introduced the card write threshold for
HS400 mode. So CardThrCtl can be supported during write operation, not
only read operation.
(Note: Only use the write threshold when mode is HS400.)

To use more compatible, removed "_rd_" from function name.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 drivers/mmc/host/dw_mmc.c | 31 +++++++++++++++++++++----------
 drivers/mmc/host/dw_mmc.h |  5 ++++-
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 5cf143b..6efda0b 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -899,13 +899,12 @@ done:
 	mci_writel(host, FIFOTH, fifoth_val);
 }
 
-static void dw_mci_ctrl_rd_thld(struct dw_mci *host, struct mmc_data *data)
+static void dw_mci_ctrl_thld(struct dw_mci *host, struct mmc_data *data)
 {
 	unsigned int blksz = data->blksz;
 	u32 blksz_depth, fifo_depth;
 	u16 thld_size;
-
-	WARN_ON(!(data->flags & MMC_DATA_READ));
+	u8 enable;
 
 	/*
 	 * CDTHRCTL doesn't exist prior to 240A (in fact that register offset is
@@ -914,8 +913,20 @@ static void dw_mci_ctrl_rd_thld(struct dw_mci *host, struct mmc_data *data)
 	if (host->verid < DW_MMC_240A)
 		return;
 
+	/*
+	 * Card write Threshold is introduced since 2.80a
+	 * It's used when HS400 mode is enabled.
+	 */
+	if (data->flags & MMC_DATA_WRITE &&
+		!(host->timing != MMC_TIMING_MMC_HS400))
+		return;
+
+	if (data->flags & MMC_DATA_WRITE)
+		enable = SDMMC_CARD_WR_THR_EN;
+	else
+		enable = SDMMC_CARD_RD_THR_EN;
+
 	if (host->timing != MMC_TIMING_MMC_HS200 &&
-	    host->timing != MMC_TIMING_MMC_HS400 &&
 	    host->timing != MMC_TIMING_UHS_SDR104)
 		goto disable;
 
@@ -931,11 +942,11 @@ static void dw_mci_ctrl_rd_thld(struct dw_mci *host, struct mmc_data *data)
 	 * Currently just choose blksz.
 	 */
 	thld_size = blksz;
-	mci_writel(host, CDTHRCTL, SDMMC_SET_RD_THLD(thld_size, 1));
+	mci_writel(host, CDTHRCTL, SDMMC_SET_THLD(thld_size, enable));
 	return;
 
 disable:
-	mci_writel(host, CDTHRCTL, SDMMC_SET_RD_THLD(0, 0));
+	mci_writel(host, CDTHRCTL, 0);
 }
 
 static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
@@ -1006,12 +1017,12 @@ static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data)
 	host->sg = NULL;
 	host->data = data;
 
-	if (data->flags & MMC_DATA_READ) {
+	if (data->flags & MMC_DATA_READ)
 		host->dir_status = DW_MCI_RECV_STATUS;
-		dw_mci_ctrl_rd_thld(host, data);
-	} else {
+	else
 		host->dir_status = DW_MCI_SEND_STATUS;
-	}
+
+	dw_mci_ctrl_thld(host, data);
 
 	if (dw_mci_submit_data_dma(host, data)) {
 		if (host->data->flags & MMC_DATA_READ)
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 1e8d838..2bf7464 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -175,7 +175,10 @@
 /* Version ID register define */
 #define SDMMC_GET_VERID(x)		((x) & 0xFFFF)
 /* Card read threshold */
-#define SDMMC_SET_RD_THLD(v, x)		(((v) & 0xFFF) << 16 | (x))
+#define SDMMC_SET_THLD(v, x)		(((v) & 0xFFF) << 16 | (x))
+#define SDMMC_CARD_WR_THR_EN		BIT(2)
+#define SDMMC_CARD_RD_THR_EN		BIT(0)
+/* UHS-1 register defines */
 #define SDMMC_UHS_18V			BIT(0)
 /* All ctrl reset bits */
 #define SDMMC_CTRL_ALL_RESET_FLAGS \
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2016-06-20  9:40 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-06-20  4:25 [PATCH 2/3] mmc: dw_mmc: add the card write threshold for HS400 mode Jaehoon Chung
2016-06-20  8:21 ` Shawn Lin
2016-06-20  8:25   ` Jaehoon Chung

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