[MMC] Switch PXAMCI to use supplied scatterlist.

This converts the PXA MCI driver to use the supplied scatter list
rather than accessing the struct request directly, thereby making
this host driver independent of the block layer.

We also clean up the driver to use a consistent driver name for
resources.

drivers/mmc/pxamci.c

@@ -44,6 +44,10 @@
 #define DBG(x...)	do { } while (0)
 #endif
 
+#define DRIVER_NAME	"pxa2xx-mci"
+
+#define NR_SG	1
+
 struct pxamci_host {
 	struct mmc_host		*mmc;
 	spinlock_t		lock;
@@ -63,9 +67,8 @@ struct pxamci_host {
 
 	dma_addr_t		sg_dma;
 	struct pxa_dma_desc	*sg_cpu;
+	unsigned int		dma_len;
 
-	dma_addr_t		dma_buf;
-	unsigned int		dma_size;
 	unsigned int		dma_dir;
 };
 
@@ -122,10 +125,9 @@ static void pxamci_disable_irq(struct pxamci_host *host, unsigned int mask)
 static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data)
 {
 	unsigned int nob = data->blocks;
-	unsigned int timeout, size;
-	dma_addr_t dma;
+	unsigned int timeout;
 	u32 dcmd;
-	int i;
+	int i, len;
 
 	host->data = data;
 
@@ -152,35 +154,22 @@ static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data)
 
 	dcmd |= DCMD_BURST32 | DCMD_WIDTH1;
 
-	host->dma_size = data->blocks << data->blksz_bits;
-	host->dma_buf = dma_map_single(mmc_dev(host->mmc), data->req->buffer,
-				       host->dma_size, host->dma_dir);
-
-	for (i = 0, size = host->dma_size, dma = host->dma_buf; size; i++) {
-		u32 len = size;
-
-		if (len > DCMD_LENGTH)
-			len = 0x1000;
+	host->dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+				   host->dma_dir);
 
+	for (i = 0; i < host->dma_len; i++) {
 		if (data->flags & MMC_DATA_READ) {
 			host->sg_cpu[i].dsadr = host->res->start + MMC_RXFIFO;
-			host->sg_cpu[i].dtadr = dma;
+			host->sg_cpu[i].dtadr = sg_dma_address(&data->sg[i]);
 		} else {
-			host->sg_cpu[i].dsadr = dma;
+			host->sg_cpu[i].dsadr = sg_dma_address(&data->sg[i]);
 			host->sg_cpu[i].dtadr = host->res->start + MMC_TXFIFO;
 		}
-		host->sg_cpu[i].dcmd = dcmd | len;
-
-		dma += len;
-		size -= len;
-
-		if (size) {
-			host->sg_cpu[i].ddadr = host->sg_dma + (i + 1) *
-						 sizeof(struct pxa_dma_desc);
-		} else {
-			host->sg_cpu[i].ddadr = DDADR_STOP;
-		}
+		host->sg_cpu[i].dcmd = dcmd | sg_dma_len(&data->sg[i]);
+		host->sg_cpu[i].ddadr = host->sg_dma + (i + 1) *
+					sizeof(struct pxa_dma_desc);
 	}
+	host->sg_cpu[host->dma_len - 1].ddadr = DDADR_STOP;
 	wmb();
 
 	DDADR(host->dma) = host->sg_dma;
@@ -276,8 +265,8 @@ static int pxamci_data_done(struct pxamci_host *host, unsigned int stat)
 		return 0;
 
 	DCSR(host->dma) = 0;
-	dma_unmap_single(mmc_dev(host->mmc), host->dma_buf, host->dma_size,
-			 host->dma_dir);
+	dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_len,
+		     host->dma_dir);
 
 	if (stat & STAT_READ_TIME_OUT)
 		data->error = MMC_ERR_TIMEOUT;
@@ -429,7 +418,7 @@ static int pxamci_probe(struct device *dev)
 	if (!r || irq == NO_IRQ)
 		return -ENXIO;
 
-	r = request_mem_region(r->start, SZ_4K, "PXAMCI");
+	r = request_mem_region(r->start, SZ_4K, DRIVER_NAME);
 	if (!r)
 		return -EBUSY;
 
@@ -443,6 +432,17 @@ static int pxamci_probe(struct device *dev)
 	mmc->f_min = 312500;
 	mmc->f_max = 20000000;
 
+	/*
+	 * We can do SG-DMA, but we don't because we never know how much
+	 * data we successfully wrote to the card.
+	 */
+	mmc->max_phys_segs = NR_SG;
+
+	/*
+	 * Our hardware DMA can handle a maximum of one page per SG entry.
+	 */
+	mmc->max_seg_size = PAGE_SIZE;
+
 	host = mmc_priv(mmc);
 	host->mmc = mmc;
 	host->dma = -1;
@@ -482,13 +482,14 @@ static int pxamci_probe(struct device *dev)
 	pxa_gpio_mode(GPIO8_MMCCS0_MD);
 	pxa_set_cken(CKEN12_MMC, 1);
 
-	host->dma = pxa_request_dma("PXAMCI", DMA_PRIO_LOW, pxamci_dma_irq, host);
+	host->dma = pxa_request_dma(DRIVER_NAME, DMA_PRIO_LOW,
+				    pxamci_dma_irq, host);
 	if (host->dma < 0) {
 		ret = -EBUSY;
 		goto out;
 	}
 
-	ret = request_irq(host->irq, pxamci_irq, 0, "PXAMCI", host);
+	ret = request_irq(host->irq, pxamci_irq, 0, DRIVER_NAME, host);
 	if (ret)
 		goto out;
 
@@ -579,7 +580,7 @@ static int pxamci_resume(struct device *dev, u32 level)
 #endif
 
 static struct device_driver pxamci_driver = {
-	.name		= "pxa2xx-mci",
+	.name		= DRIVER_NAME,
 	.bus		= &platform_bus_type,
 	.probe		= pxamci_probe,
 	.remove		= pxamci_remove,