Revert "OMAP: HSMMC: Implement scatter-gather emulation"

This reverts commit 038d0d2f.

Looks like this patch breaks MMC at least on overo unless
MMC is forced to use only one data line.

Revert for now until the problem is fixed.
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/mmc/host/omap_hsmmc.c

@@ -98,6 +98,9 @@
 #define OMAP_MMC1_DEVID		0
 #define OMAP_MMC2_DEVID		1
 
+#define OMAP_MMC_DATADIR_NONE	0
+#define OMAP_MMC_DATADIR_READ	1
+#define OMAP_MMC_DATADIR_WRITE	2
 #define MMC_TIMEOUT_MS		20
 #define OMAP_MMC_MASTER_CLOCK	96000000
 #define DRIVER_NAME		"mmci-omap-hs"
@@ -136,14 +139,16 @@ struct mmc_omap_host {
 	resource_size_t		mapbase;
 	unsigned int		id;
 	unsigned int		dma_len;
-	unsigned int		dma_sg_idx;
+	unsigned int		dma_dir;
 	unsigned char		bus_mode;
+	unsigned char		datadir;
 	u32			*buffer;
 	u32			bytesleft;
 	int			suspended;
 	int			irq;
 	int			carddetect;
 	int			use_dma, dma_ch;
+	int			initstr;
 	int			slot_id;
 	int			dbclk_enabled;
 
@@ -311,15 +316,6 @@ mmc_omap_start_command(struct mmc_omap_host *host, struct mmc_command *cmd,
 	OMAP_HSMMC_WRITE(host->base, CMD, cmdreg);
 }
 
-static int
-mmc_omap_get_dma_dir(struct mmc_omap_host *host, struct mmc_data *data)
-{
-	if (data->flags & MMC_DATA_WRITE)
-		return DMA_TO_DEVICE;
-	else
-		return DMA_FROM_DEVICE;
-}
-
 /*
  * Notify the transfer complete to MMC core
  */
@@ -330,7 +326,9 @@ mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data)
 
 	if (host->use_dma && host->dma_ch != -1)
 		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_len,
-			mmc_omap_get_dma_dir(host, data));
+			host->dma_dir);
+
+	host->datadir = OMAP_MMC_DATADIR_NONE;
 
 	if (!data->error)
 		data->bytes_xfered += data->blocks * (data->blksz);
@@ -382,12 +380,13 @@ static void mmc_dma_cleanup(struct mmc_omap_host *host)
 
 	if (host->use_dma && host->dma_ch != -1) {
 		dma_unmap_sg(mmc_dev(host->mmc), host->data->sg, host->dma_len,
-			mmc_omap_get_dma_dir(host, host->data));
+			host->dma_dir);
 		omap_free_dma(host->dma_ch);
 		host->dma_ch = -1;
 		up(&host->sem);
 	}
 	host->data = NULL;
+	host->datadir = OMAP_MMC_DATADIR_NONE;
 }
 
 /*
@@ -599,55 +598,6 @@ static irqreturn_t omap_mmc_cd_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int mmc_omap_get_dma_sync_dev(struct mmc_omap_host *host,
-				     struct mmc_data *data)
-{
-	int sync_dev;
-
-	if (data->flags & MMC_DATA_WRITE) {
-		if (host->id == OMAP_MMC1_DEVID)
-			sync_dev = OMAP24XX_DMA_MMC1_TX;
-		else
-			sync_dev = OMAP24XX_DMA_MMC2_TX;
-	} else {
-		if (host->id == OMAP_MMC1_DEVID)
-			sync_dev = OMAP24XX_DMA_MMC1_RX;
-		else
-			sync_dev = OMAP24XX_DMA_MMC2_RX;
-	}
-	return sync_dev;
-}
-
-static void mmc_omap_config_dma_params(struct mmc_omap_host *host,
-				       struct mmc_data *data,
-				       struct scatterlist *sgl)
-{
-	int blksz, nblk, dma_ch;
-
-	dma_ch = host->dma_ch;
-	if (data->flags & MMC_DATA_WRITE) {
-		omap_set_dma_dest_params(dma_ch, 0, OMAP_DMA_AMODE_CONSTANT,
-			(host->mapbase + OMAP_HSMMC_DATA), 0, 0);
-		omap_set_dma_src_params(dma_ch, 0, OMAP_DMA_AMODE_POST_INC,
-			sg_dma_address(sgl), 0, 0);
-	} else {
-		omap_set_dma_src_params(dma_ch, 0, OMAP_DMA_AMODE_CONSTANT,
-					(host->mapbase + OMAP_HSMMC_DATA), 0, 0);
-		omap_set_dma_dest_params(dma_ch, 0, OMAP_DMA_AMODE_POST_INC,
-			sg_dma_address(sgl), 0, 0);
-	}
-
-	blksz = host->data->blksz;
-	nblk = sg_dma_len(sgl) / blksz;
-
-	omap_set_dma_transfer_params(dma_ch, OMAP_DMA_DATA_TYPE_S32,
-			blksz / 4, nblk, OMAP_DMA_SYNC_FRAME,
-			mmc_omap_get_dma_sync_dev(host, data),
-			!(data->flags & MMC_DATA_WRITE));
-
-	omap_start_dma(dma_ch);
-}
-
 /*
  * DMA call back function
  */
@@ -661,14 +611,6 @@ static void mmc_omap_dma_cb(int lch, u16 ch_status, void *data)
 	if (host->dma_ch < 0)
 		return;
 
-	host->dma_sg_idx++;
-	if (host->dma_sg_idx < host->dma_len) {
-		/* Fire up the next transfer. */
-		mmc_omap_config_dma_params(host, host->data,
-					   host->data->sg + host->dma_sg_idx);
-		return;
-	}
-
 	omap_free_dma(host->dma_ch);
 	host->dma_ch = -1;
 	/*
@@ -678,29 +620,39 @@ static void mmc_omap_dma_cb(int lch, u16 ch_status, void *data)
 	up(&host->sem);
 }
 
+/*
+ * Configure dma src and destination parameters
+ */
+static int mmc_omap_config_dma_param(int sync_dir, struct mmc_omap_host *host,
+				struct mmc_data *data)
+{
+	if (sync_dir == 0) {
+		omap_set_dma_dest_params(host->dma_ch, 0,
+			OMAP_DMA_AMODE_CONSTANT,
+			(host->mapbase + OMAP_HSMMC_DATA), 0, 0);
+		omap_set_dma_src_params(host->dma_ch, 0,
+			OMAP_DMA_AMODE_POST_INC,
+			sg_dma_address(&data->sg[0]), 0, 0);
+	} else {
+		omap_set_dma_src_params(host->dma_ch, 0,
+			OMAP_DMA_AMODE_CONSTANT,
+			(host->mapbase + OMAP_HSMMC_DATA), 0, 0);
+		omap_set_dma_dest_params(host->dma_ch, 0,
+			OMAP_DMA_AMODE_POST_INC,
+			sg_dma_address(&data->sg[0]), 0, 0);
+	}
+	return 0;
+}
 /*
  * Routine to configure and start DMA for the MMC card
  */
 static int
 mmc_omap_start_dma_transfer(struct mmc_omap_host *host, struct mmc_request *req)
 {
-	int dma_ch = 0, ret = 0, err = 1, i;
+	int sync_dev, sync_dir = 0;
+	int dma_ch = 0, ret = 0, err = 1;
 	struct mmc_data *data = req->data;
 
-	/* Sanity check: all the SG entries must be aligned by block size. */
-	for (i = 0; i < host->dma_len; i++) {
-		struct scatterlist *sgl;
-
-		sgl = data->sg + i;
-		if (sgl->length % data->blksz)
-			return -EINVAL;
-	}
-	if ((data->blksz % 4) != 0)
-		/* REVISIT: The MMC buffer increments only when MSB is written.
-		 * Return error for blksz which is non multiple of four.
-		 */
-		return -EINVAL;
-
 	/*
 	 * If for some reason the DMA transfer is still active,
 	 * we wait for timeout period and free the dma
@@ -719,22 +671,49 @@ mmc_omap_start_dma_transfer(struct mmc_omap_host *host, struct mmc_request *req)
 			return err;
 	}
 
-	ret = omap_request_dma(mmc_omap_get_dma_sync_dev(host, data), "MMC/SD",
-			       mmc_omap_dma_cb,host, &dma_ch);
+	if (!(data->flags & MMC_DATA_WRITE)) {
+		host->dma_dir = DMA_FROM_DEVICE;
+		if (host->id == OMAP_MMC1_DEVID)
+			sync_dev = OMAP24XX_DMA_MMC1_RX;
+		else
+			sync_dev = OMAP24XX_DMA_MMC2_RX;
+	} else {
+		host->dma_dir = DMA_TO_DEVICE;
+		if (host->id == OMAP_MMC1_DEVID)
+			sync_dev = OMAP24XX_DMA_MMC1_TX;
+		else
+			sync_dev = OMAP24XX_DMA_MMC2_TX;
+	}
+
+	ret = omap_request_dma(sync_dev, "MMC/SD", mmc_omap_dma_cb,
+			host, &dma_ch);
 	if (ret != 0) {
-		dev_err(mmc_dev(host->mmc),
+		dev_dbg(mmc_dev(host->mmc),
 			"%s: omap_request_dma() failed with %d\n",
 			mmc_hostname(host->mmc), ret);
 		return ret;
 	}
 
 	host->dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg,
-			data->sg_len, mmc_omap_get_dma_dir(host, data));
+			data->sg_len, host->dma_dir);
 	host->dma_ch = dma_ch;
-	host->dma_sg_idx = 0;
 
-	mmc_omap_config_dma_params(host, data, data->sg);
+	if (!(data->flags & MMC_DATA_WRITE))
+		mmc_omap_config_dma_param(1, host, data);
+	else
+		mmc_omap_config_dma_param(0, host, data);
+
+	if ((data->blksz % 4) == 0)
+		omap_set_dma_transfer_params(dma_ch, OMAP_DMA_DATA_TYPE_S32,
+			(data->blksz / 4), data->blocks, OMAP_DMA_SYNC_FRAME,
+			sync_dev, sync_dir);
+	else
+		/* REVISIT: The MMC buffer increments only when MSB is written.
+		 * Return error for blksz which is non multiple of four.
+		 */
+		return -EINVAL;
 
+	omap_start_dma(dma_ch);
 	return 0;
 }
 
@@ -784,6 +763,7 @@ mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
 	host->data = req->data;
 
 	if (req->data == NULL) {
+		host->datadir = OMAP_MMC_DATADIR_NONE;
 		OMAP_HSMMC_WRITE(host->base, BLK, 0);
 		return 0;
 	}
@@ -792,6 +772,9 @@ mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
 					| (req->data->blocks << 16));
 	set_data_timeout(host, req);
 
+	host->datadir = (req->data->flags & MMC_DATA_WRITE) ?
+			OMAP_MMC_DATADIR_WRITE : OMAP_MMC_DATADIR_READ;
+
 	if (host->use_dma) {
 		ret = mmc_omap_start_dma_transfer(host, req);
 		if (ret != 0) {
@@ -934,7 +917,7 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
 	struct mmc_host *mmc;
 	struct mmc_omap_host *host = NULL;
 	struct resource *res;
-	int ret = 0, irq;
+	int ret = 0, irq, reg;
 	u32 hctl, capa;
 
 	if (pdata == NULL) {
@@ -1028,11 +1011,10 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
 		else
 			host->dbclk_enabled = 1;
 
-	/* Since we do only SG emulation, we can have as many segs
-	 * as we want. */
-	mmc->max_phys_segs = 1024;
-	mmc->max_hw_segs = 1024;
-
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+	mmc->max_phys_segs = 1;
+	mmc->max_hw_segs = 1;
+#endif
 	mmc->max_blk_size = 512;       /* Block Length at max can be 1024 */
 	mmc->max_blk_count = 0xFFFF;    /* No. of Blocks is 16 bits */
 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;