From a65f51b97886f0b1d911eb1ea951fce9efd1700f Mon Sep 17 00:00:00 2001
From: huang lin <hl@rock-chips.com>
Date: Tue, 17 Nov 2015 14:20:22 +0800
Subject: mmc: dw_mmc: support fifo mode in dwc mmc driver

some soc(rk3036 etc) use dw_mmc but do not have internal dma,
so we implement fifo mode to read and write data.

Signed-off-by: Lin Huang <hl@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
---
 drivers/mmc/dw_mmc.c | 85 +++++++++++++++++++++++++++++++++++++++++-----------
 include/dwmmc.h      |  5 ++++
 2 files changed, 72 insertions(+), 18 deletions(-)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index bee8fab332..909e3caf18 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -94,12 +94,21 @@ static void dwmci_prepare_data(struct dwmci_host *host,
 	dwmci_writel(host, DWMCI_BYTCNT, data->blocksize * data->blocks);
 }
 
-static int dwmci_data_transfer(struct dwmci_host *host)
+static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
 {
 	int ret = 0;
-	unsigned int timeout = 240000;
-	u32 mask;
+	u32 timeout = 240000;
+	u32 mask, size, i, len = 0;
+	u32 *buf = NULL;
 	ulong start = get_timer(0);
+	u32 fifo_depth = (((host->fifoth_val & RX_WMARK_MASK) >>
+			    RX_WMARK_SHIFT) + 1) * 2;
+
+	size = data->blocksize * data->blocks / 4;
+	if (data->flags == MMC_DATA_READ)
+		buf = (unsigned int *)data->dest;
+	else
+		buf = (unsigned int *)data->src;
 
 	for (;;) {
 		mask = dwmci_readl(host, DWMCI_RINTSTS);
@@ -110,6 +119,36 @@ static int dwmci_data_transfer(struct dwmci_host *host)
 			break;
 		}
 
+		if (host->fifo_mode && size) {
+			if (data->flags == MMC_DATA_READ) {
+				if ((dwmci_readl(host, DWMCI_RINTSTS) &&
+				     DWMCI_INTMSK_RXDR)) {
+					len = dwmci_readl(host, DWMCI_STATUS);
+					len = (len >> DWMCI_FIFO_SHIFT) &
+						    DWMCI_FIFO_MASK;
+					for (i = 0; i < len; i++)
+						*buf++ =
+						dwmci_readl(host, DWMCI_DATA);
+					dwmci_writel(host, DWMCI_RINTSTS,
+						     DWMCI_INTMSK_RXDR);
+				}
+			} else {
+				if ((dwmci_readl(host, DWMCI_RINTSTS) &&
+				     DWMCI_INTMSK_TXDR)) {
+					len = dwmci_readl(host, DWMCI_STATUS);
+					len = fifo_depth - ((len >>
+						   DWMCI_FIFO_SHIFT) &
+						   DWMCI_FIFO_MASK);
+					for (i = 0; i < len; i++)
+						dwmci_writel(host, DWMCI_DATA,
+							     *buf++);
+					dwmci_writel(host, DWMCI_RINTSTS,
+						     DWMCI_INTMSK_TXDR);
+				}
+			}
+			size = size > len ? (size - len) : 0;
+		}
+
 		/* Data arrived correctly. */
 		if (mask & DWMCI_INTMSK_DTO) {
 			ret = 0;
@@ -165,17 +204,24 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 	dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_ALL);
 
 	if (data) {
-		if (data->flags == MMC_DATA_READ) {
-			bounce_buffer_start(&bbstate, (void*)data->dest,
-					    data->blocksize *
-					    data->blocks, GEN_BB_WRITE);
+		if (host->fifo_mode) {
+			dwmci_writel(host, DWMCI_BLKSIZ, data->blocksize);
+			dwmci_writel(host, DWMCI_BYTCNT,
+				     data->blocksize * data->blocks);
+			dwmci_wait_reset(host, DWMCI_CTRL_FIFO_RESET);
 		} else {
-			bounce_buffer_start(&bbstate, (void*)data->src,
-					    data->blocksize *
-					    data->blocks, GEN_BB_READ);
+			if (data->flags == MMC_DATA_READ) {
+				bounce_buffer_start(&bbstate, (void*)data->dest,
+						data->blocksize *
+						data->blocks, GEN_BB_WRITE);
+			} else {
+				bounce_buffer_start(&bbstate, (void*)data->src,
+						data->blocksize *
+						data->blocks, GEN_BB_READ);
+			}
+			dwmci_prepare_data(host, data, cur_idmac,
+					   bbstate.bounce_buffer);
 		}
-		dwmci_prepare_data(host, data, cur_idmac,
-				   bbstate.bounce_buffer);
 	}
 
 	dwmci_writel(host, DWMCI_CMDARG, cmd->cmdarg);
@@ -249,12 +295,15 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 	}
 
 	if (data) {
-		ret = dwmci_data_transfer(host);
-
-		ctrl = dwmci_readl(host, DWMCI_CTRL);
-		ctrl &= ~(DWMCI_DMA_EN);
-		dwmci_writel(host, DWMCI_CTRL, ctrl);
-		bounce_buffer_stop(&bbstate);
+		ret = dwmci_data_transfer(host, data);
+
+		/* only dma mode need it */
+		if (!host->fifo_mode) {
+			ctrl = dwmci_readl(host, DWMCI_CTRL);
+			ctrl &= ~(DWMCI_DMA_EN);
+			dwmci_writel(host, DWMCI_CTRL, ctrl);
+			bounce_buffer_stop(&bbstate);
+		}
 	}
 
 	udelay(100);
diff --git a/include/dwmmc.h b/include/dwmmc.h
index 25cf42c606..05b0817fe1 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -105,6 +105,8 @@
 
 /* Status Register */
 #define DWMCI_BUSY		(1 << 9)
+#define DWMCI_FIFO_MASK		0x1ff
+#define DWMCI_FIFO_SHIFT	17
 
 /* FIFOTH Register */
 #define MSIZE(x)		((x) << 28)
@@ -180,6 +182,9 @@ struct dwmci_host {
 	unsigned int (*get_mmc_clk)(struct dwmci_host *host, uint freq);
 
 	struct mmc_config cfg;
+
+	/* use fifo mode to read and write data */
+	bool fifo_mode;
 };
 
 struct dwmci_idmac {
-- 
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