mmc: omap_hsmmc: Add support for DMA (ADMA2)

The omap hsmmc host controller can have the ADMA2 feature. It brings better
read and write throughput.
On most SOC, the capability is read from the hl_hwinfo register. On OMAP3,
DMA support is compiled out.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/include/asm/omap_mmc.h

@@ -29,7 +29,10 @@
 
 struct hsmmc {
 #ifndef CONFIG_OMAP34XX
-	unsigned char res0[0x100];
+	unsigned int hl_rev;
+	unsigned int hl_hwinfo;
+	unsigned int hl_sysconfig;
+	unsigned char res0[0xf4];
 #endif
 	unsigned char res1[0x10];
 	unsigned int sysconfig;		/* 0x10 */
@@ -52,6 +55,9 @@ struct hsmmc {
 	unsigned int ie;		/* 0x134 */
 	unsigned char res4[0x8];
 	unsigned int capa;		/* 0x140 */
+	unsigned char res5[0x10];
+	unsigned int admaes;		/* 0x154 */
+	unsigned int admasal;		/* 0x158 */
 };
 
 struct omap_hsmmc_plat {
@@ -64,6 +70,7 @@ struct omap_hsmmc_plat {
 /*
  * OMAP HS MMC Bit definitions
  */
+#define MADMA_EN			(0x1 << 0)
 #define MMC_SOFTRESET			(0x1 << 1)
 #define RESETDONE			(0x1 << 0)
 #define NOOPENDRAIN			(0x0 << 0)
@@ -80,6 +87,7 @@ struct omap_hsmmc_plat {
 #define WPP_ACTIVEHIGH			(0x0 << 8)
 #define RESERVED_MASK			(0x3 << 9)
 #define CTPL_MMC_SD			(0x0 << 11)
+#define DMA_MASTER			(0x1 << 20)
 #define BLEN_512BYTESLEN		(0x200 << 0)
 #define NBLK_STPCNT			(0x0 << 16)
 #define DE_DISABLE			(0x0 << 0)
@@ -119,6 +127,7 @@ struct omap_hsmmc_plat {
 #define SDBP_PWRON			(0x1 << 8)
 #define SDVS_1V8			(0x5 << 9)
 #define SDVS_3V0			(0x6 << 9)
+#define DMA_SELECT			(0x2 << 3)
 #define ICE_MASK			(0x1 << 0)
 #define ICE_STOP			(0x0 << 0)
 #define ICS_MASK			(0x1 << 1)
@@ -148,6 +157,7 @@ struct omap_hsmmc_plat {
 #define IE_DTO				(0x01 << 20)
 #define IE_DCRC				(0x01 << 21)
 #define IE_DEB				(0x01 << 22)
+#define IE_ADMAE			(0x01 << 25)
 #define IE_CERR				(0x01 << 28)
 #define IE_BADA				(0x01 << 29)
 

drivers/mmc/omap_hsmmc.c

@@ -25,6 +25,7 @@
 #include <config.h>
 #include <common.h>
 #include <malloc.h>
+#include <memalign.h>
 #include <mmc.h>
 #include <part.h>
 #include <i2c.h>
@@ -71,11 +72,45 @@ struct omap_hsmmc_data {
 	int wp_gpio;
 #endif
 #endif
+	u8 controller_flags;
+#ifndef CONFIG_OMAP34XX
+	struct omap_hsmmc_adma_desc *adma_desc_table;
+	uint desc_slot;
+#endif
+};
+
+#ifndef CONFIG_OMAP34XX
+struct omap_hsmmc_adma_desc {
+	u8 attr;
+	u8 reserved;
+	u16 len;
+	u32 addr;
 };
 
+#define ADMA_MAX_LEN	63488
+
+/* Decriptor table defines */
+#define ADMA_DESC_ATTR_VALID		BIT(0)
+#define ADMA_DESC_ATTR_END		BIT(1)
+#define ADMA_DESC_ATTR_INT		BIT(2)
+#define ADMA_DESC_ATTR_ACT1		BIT(4)
+#define ADMA_DESC_ATTR_ACT2		BIT(5)
+
+#define ADMA_DESC_TRANSFER_DATA		ADMA_DESC_ATTR_ACT2
+#define ADMA_DESC_LINK_DESC	(ADMA_DESC_ATTR_ACT1 | ADMA_DESC_ATTR_ACT2)
+#endif
+
 /* If we fail after 1 second wait, something is really bad */
 #define MAX_RETRY_MS	1000
 
+/* DMA transfers can take a long time if a lot a data is transferred.
+ * The timeout must take in account the amount of data. Let's assume
+ * that the time will never exceed 333 ms per MB (in other word we assume
+ * that the bandwidth is always above 3MB/s).
+ */
+#define DMA_TIMEOUT_PER_MB	333
+#define OMAP_HSMMC_USE_ADMA			BIT(2)
+
 static int mmc_read_data(struct hsmmc *mmc_base, char *buf, unsigned int size);
 static int mmc_write_data(struct hsmmc *mmc_base, const char *buf,
 			unsigned int siz);
@@ -242,6 +277,11 @@ static int omap_hsmmc_init_setup(struct mmc *mmc)
 			return -ETIMEDOUT;
 		}
 	}
+#ifndef CONFIG_OMAP34XX
+	reg_val = readl(&mmc_base->hl_hwinfo);
+	if (reg_val & MADMA_EN)
+		priv->controller_flags |= OMAP_HSMMC_USE_ADMA;
+#endif
 	writel(DTW_1_BITMODE | SDBP_PWROFF | SDVS_3V0, &mmc_base->hctl);
 	writel(readl(&mmc_base->capa) | VS30_3V0SUP | VS18_1V8SUP,
 		&mmc_base->capa);
@@ -269,8 +309,8 @@ static int omap_hsmmc_init_setup(struct mmc *mmc)
 	writel(readl(&mmc_base->hctl) | SDBP_PWRON, &mmc_base->hctl);
 
 	writel(IE_BADA | IE_CERR | IE_DEB | IE_DCRC | IE_DTO | IE_CIE |
-		IE_CEB | IE_CCRC | IE_CTO | IE_BRR | IE_BWR | IE_TC | IE_CC,
-		&mmc_base->ie);
+		IE_CEB | IE_CCRC | IE_ADMAE | IE_CTO | IE_BRR | IE_BWR | IE_TC |
+		IE_CC, &mmc_base->ie);
 
 	mmc_init_stream(mmc_base);
 
@@ -322,6 +362,118 @@ static void mmc_reset_controller_fsm(struct hsmmc *mmc_base, u32 bit)
 		}
 	}
 }
+
+#ifndef CONFIG_OMAP34XX
+static void omap_hsmmc_adma_desc(struct mmc *mmc, char *buf, u16 len, bool end)
+{
+	struct omap_hsmmc_data *priv = omap_hsmmc_get_data(mmc);
+	struct omap_hsmmc_adma_desc *desc;
+	u8 attr;
+
+	desc = &priv->adma_desc_table[priv->desc_slot];
+
+	attr = ADMA_DESC_ATTR_VALID | ADMA_DESC_TRANSFER_DATA;
+	if (!end)
+		priv->desc_slot++;
+	else
+		attr |= ADMA_DESC_ATTR_END;
+
+	desc->len = len;
+	desc->addr = (u32)buf;
+	desc->reserved = 0;
+	desc->attr = attr;
+}
+
+static void omap_hsmmc_prepare_adma_table(struct mmc *mmc,
+					  struct mmc_data *data)
+{
+	uint total_len = data->blocksize * data->blocks;
+	uint desc_count = DIV_ROUND_UP(total_len, ADMA_MAX_LEN);
+	struct omap_hsmmc_data *priv = omap_hsmmc_get_data(mmc);
+	int i = desc_count;
+	char *buf;
+
+	priv->desc_slot = 0;
+	priv->adma_desc_table = (struct omap_hsmmc_adma_desc *)
+				memalign(ARCH_DMA_MINALIGN, desc_count *
+				sizeof(struct omap_hsmmc_adma_desc));
+
+	if (data->flags & MMC_DATA_READ)
+		buf = data->dest;
+	else
+		buf = (char *)data->src;
+
+	while (--i) {
+		omap_hsmmc_adma_desc(mmc, buf, ADMA_MAX_LEN, false);
+		buf += ADMA_MAX_LEN;
+		total_len -= ADMA_MAX_LEN;
+	}
+
+	omap_hsmmc_adma_desc(mmc, buf, total_len, true);
+
+	flush_dcache_range((long)priv->adma_desc_table,
+			   (long)priv->adma_desc_table +
+			   ROUND(desc_count *
+			   sizeof(struct omap_hsmmc_adma_desc),
+			   ARCH_DMA_MINALIGN));
+}
+
+static void omap_hsmmc_prepare_data(struct mmc *mmc, struct mmc_data *data)
+{
+	struct hsmmc *mmc_base;
+	struct omap_hsmmc_data *priv = omap_hsmmc_get_data(mmc);
+	u32 val;
+	char *buf;
+
+	mmc_base = priv->base_addr;
+	omap_hsmmc_prepare_adma_table(mmc, data);
+
+	if (data->flags & MMC_DATA_READ)
+		buf = data->dest;
+	else
+		buf = (char *)data->src;
+
+	val = readl(&mmc_base->hctl);
+	val |= DMA_SELECT;
+	writel(val, &mmc_base->hctl);
+
+	val = readl(&mmc_base->con);
+	val |= DMA_MASTER;
+	writel(val, &mmc_base->con);
+
+	writel((u32)priv->adma_desc_table, &mmc_base->admasal);
+
+	flush_dcache_range((u32)buf,
+			   (u32)buf +
+			   ROUND(data->blocksize * data->blocks,
+				 ARCH_DMA_MINALIGN));
+}
+
+static void omap_hsmmc_dma_cleanup(struct mmc *mmc)
+{
+	struct hsmmc *mmc_base;
+	struct omap_hsmmc_data *priv = omap_hsmmc_get_data(mmc);
+	u32 val;
+
+	mmc_base = priv->base_addr;
+
+	val = readl(&mmc_base->con);
+	val &= ~DMA_MASTER;
+	writel(val, &mmc_base->con);
+
+	val = readl(&mmc_base->hctl);
+	val &= ~DMA_SELECT;
+	writel(val, &mmc_base->hctl);
+
+	kfree(priv->adma_desc_table);
+}
+#else
+#define omap_hsmmc_adma_desc
+#define omap_hsmmc_prepare_adma_table
+#define omap_hsmmc_prepare_data
+#define omap_hsmmc_dma_cleanup
+#endif
+
 #if !CONFIG_IS_ENABLED(DM_MMC)
 static int omap_hsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 			struct mmc_data *data)
@@ -332,6 +484,10 @@ static int omap_hsmmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
 			struct mmc_data *data)
 {
 	struct omap_hsmmc_data *priv = dev_get_priv(dev);
+#ifndef CONFIG_OMAP34XX
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct mmc *mmc = upriv->mmc;
+#endif
 #endif
 	struct hsmmc *mmc_base;
 	unsigned int flags, mmc_stat;
@@ -405,6 +561,14 @@ static int omap_hsmmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
 			flags |= (DP_DATA | DDIR_READ);
 		else
 			flags |= (DP_DATA | DDIR_WRITE);
+
+#ifndef CONFIG_OMAP34XX
+		if ((priv->controller_flags & OMAP_HSMMC_USE_ADMA) &&
+		    !mmc_is_tuning_cmd(cmd->cmdidx)) {
+			omap_hsmmc_prepare_data(mmc, data);
+			flags |= DE_ENABLE;
+		}
+#endif
 	}
 
 	writel(cmd->cmdarg, &mmc_base->arg);
@@ -414,7 +578,7 @@ static int omap_hsmmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
 	start = get_timer(0);
 	do {
 		mmc_stat = readl(&mmc_base->stat);
-		if (get_timer(0) - start > MAX_RETRY_MS) {
+		if (get_timer(start) > MAX_RETRY_MS) {
 			printf("%s : timeout: No status update\n", __func__);
 			return -ETIMEDOUT;
 		}
@@ -441,6 +605,41 @@ static int omap_hsmmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
 		}
 	}
 
+#ifndef CONFIG_OMAP34XX
+	if ((priv->controller_flags & OMAP_HSMMC_USE_ADMA) && data &&
+	    !mmc_is_tuning_cmd(cmd->cmdidx)) {
+		u32 sz_mb, timeout;
+
+		if (mmc_stat & IE_ADMAE) {
+			omap_hsmmc_dma_cleanup(mmc);
+			return -EIO;
+		}
+
+		sz_mb = DIV_ROUND_UP(data->blocksize *  data->blocks, 1 << 20);
+		timeout = sz_mb * DMA_TIMEOUT_PER_MB;
+		if (timeout < MAX_RETRY_MS)
+			timeout = MAX_RETRY_MS;
+
+		start = get_timer(0);
+		do {
+			mmc_stat = readl(&mmc_base->stat);
+			if (mmc_stat & TC_MASK) {
+				writel(readl(&mmc_base->stat) | TC_MASK,
+				       &mmc_base->stat);
+				break;
+			}
+			if (get_timer(start) > timeout) {
+				printf("%s : DMA timeout: No status update\n",
+				       __func__);
+				return -ETIMEDOUT;
+			}
+		} while (1);
+
+		omap_hsmmc_dma_cleanup(mmc);
+		return 0;
+	}
+#endif
+
 	if (data && (data->flags & MMC_DATA_READ)) {
 		mmc_read_data(mmc_base,	data->dest,
 				data->blocksize * data->blocks);