s3cmci: Kconfig selection for PIO/DMA/Both

Add a selection for the data transfer mode of the s3cmci driver, allowing
for either a configuration or rumtime selection of the use of the DMA or
PIO transfer code.

The PIO only mode is 476 bytes smaller than the driver with both methods
compiled in.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
index 7660ac4..0adf318 100644
--- a/drivers/mmc/host/s3cmci.c
+++ b/drivers/mmc/host/s3cmci.c
@@ -164,6 +164,25 @@
 
 #endif /* CONFIG_MMC_DEBUG */
 
+/**
+ * s3cmci_host_usedma - return whether the host is using dma or pio
+ * @host: The host state
+ *
+ * Return true if the host is using DMA to transfer data, else false
+ * to use PIO mode. Will return static data depending on the driver
+ * configuration.
+ */
+static inline bool s3cmci_host_usedma(struct s3cmci_host *host)
+{
+#ifdef CONFIG_MMC_S3C_PIO
+	return false;
+#elif defined(CONFIG_MMC_S3C_DMA)
+	return true;
+#else
+	return host->dodma;
+#endif
+}
+
 static inline u32 enable_imask(struct s3cmci_host *host, u32 imask)
 {
 	u32 newmask;
@@ -560,7 +579,7 @@
 		goto irq_out;
 	}
 
-	if (!host->dodma) {
+	if (!s3cmci_host_usedma(host)) {
 		if ((host->pio_active == XFER_WRITE) &&
 		    (mci_fsta & S3C2410_SDIFSTA_TFDET)) {
 
@@ -796,7 +815,7 @@
 
 	if (cmd->data && (cmd->error == 0) &&
 	    (cmd->data->error == 0)) {
-		if (host->dodma && (!host->dma_complete)) {
+		if (s3cmci_host_usedma(host) && (!host->dma_complete)) {
 			dbg(host, dbg_dma, "DMA Missing!\n");
 			return;
 		}
@@ -848,7 +867,7 @@
 	/* If we had an error while transfering data we flush the
 	 * DMA channel and the fifo to clear out any garbage. */
 	if (mrq->data->error != 0) {
-		if (host->dodma)
+		if (s3cmci_host_usedma(host))
 			s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
 
 		if (host->is2440) {
@@ -968,7 +987,7 @@
 
 	dcon  = data->blocks & S3C2410_SDIDCON_BLKNUM_MASK;
 
-	if (host->dodma)
+	if (s3cmci_host_usedma(host))
 		dcon |= S3C2410_SDIDCON_DMAEN;
 
 	if (host->bus_width == MMC_BUS_WIDTH_4)
@@ -1114,7 +1133,7 @@
 			return;
 		}
 
-		if (host->dodma)
+		if (s3cmci_host_usedma(host))
 			res = s3cmci_prepare_dma(host, cmd->data);
 		else
 			res = s3cmci_prepare_pio(host, cmd->data);
@@ -1398,7 +1417,7 @@
 	seq_printf(seq, "IRQ disabled = %d\n", host->irq_disabled);
 	seq_printf(seq, "IRQ state = %d\n", host->irq_state);
 	seq_printf(seq, "CD IRQ = %d\n", host->irq_cd);
-	seq_printf(seq, "Do DMA = %d\n", host->dodma);
+	seq_printf(seq, "Do DMA = %d\n", s3cmci_host_usedma(host));
 	seq_printf(seq, "SDIIMSK at %d\n", host->sdiimsk);
 	seq_printf(seq, "SDIDATA at %d\n", host->sdidata);
 
@@ -1559,12 +1578,15 @@
 		host->clk_div	= 2;
 	}
 
-	host->dodma		= 0;
 	host->complete_what 	= COMPLETION_NONE;
 	host->pio_active 	= XFER_NONE;
 
 	host->dma		= S3CMCI_DMA;
 
+#ifdef CONFIG_MMC_S3C_PIODMA
+	host->dodma		= host->pdata->dma;
+#endif
+
 	host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!host->mem) {
 		dev_err(&pdev->dev,
@@ -1702,7 +1724,8 @@
 	s3cmci_debugfs_attach(host);
 
 	platform_set_drvdata(pdev, mmc);
-	dev_info(&pdev->dev, "initialisation done.\n");
+	dev_info(&pdev->dev, "%s - using %s\n", mmc_hostname(mmc),
+		 s3cmci_host_usedma(host) ? "dma" : "pio");
 
 	return 0;