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-rw-r--r--drivers/mmc/host/Kconfig34
-rw-r--r--drivers/mmc/host/s3cmci.c39
2 files changed, 65 insertions, 8 deletions
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 7cb057f3f88..cf6a6545240 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -276,6 +276,40 @@ config MMC_S3C
If unsure, say N.
+choice
+ prompt "Samsung S3C SD/MMC transfer code"
+ depends on MMC_S3C
+
+config MMC_S3C_PIO
+ bool "Use PIO transfers only"
+ help
+ Use PIO to transfer data between memory and the hardware.
+
+ PIO is slower than DMA as it requires CPU instructions to
+ move the data. This has been the traditional default for
+ the S3C MCI driver.
+
+config MMC_S3C_DMA
+ bool "Use DMA transfers only (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ Use DMA to transfer data between memory and the hardare.
+
+ Currently, the DMA support in this driver seems to not be
+ working properly and needs to be debugged before this
+ option is useful.
+
+config MMC_S3C_PIODMA
+ bool "Support for both PIO and DMA (EXPERIMENTAL)"
+ help
+ Compile both the PIO and DMA transfer routines into the
+ driver and let the platform select at run-time which one
+ is best.
+
+ See notes for the DMA option.
+
+endchoice
+
config MMC_SDRICOH_CS
tristate "MMC/SD driver for Ricoh Bay1Controllers (EXPERIMENTAL)"
depends on EXPERIMENTAL && PCI && PCMCIA
diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
index 7660ac4572e..0adf31895f2 100644
--- a/drivers/mmc/host/s3cmci.c
+++ b/drivers/mmc/host/s3cmci.c
@@ -164,6 +164,25 @@ static void dbg_dumpregs(struct s3cmci_host *host, char *prefix) { }
#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 @@ static irqreturn_t s3cmci_irq(int irq, void *dev_id)
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 @@ static void finalize_request(struct s3cmci_host *host)
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 @@ static void finalize_request(struct s3cmci_host *host)
/* 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 @@ static int s3cmci_setup_data(struct s3cmci_host *host, struct mmc_data *data)
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 @@ static void s3cmci_send_request(struct mmc_host *mmc)
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 @@ static int s3cmci_state_show(struct seq_file *seq, void *v)
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 @@ static int __devinit s3cmci_probe(struct platform_device *pdev)
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 @@ static int __devinit s3cmci_probe(struct platform_device *pdev)
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;