Commit 26f14947 authored by Ben Dooks's avatar Ben Dooks Committed by Linus Torvalds
Browse files

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: default avatarBen Dooks <ben@simtec.co.uk>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c2258893

arch/arm/plat-s3c24xx/include/plat/mci.h

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
struct s3c24xx_mci_pdata {

	unsigned int	wprotect_invert : 1;

	unsigned int	detect_invert : 1;   /* set => detect active high. */

	unsigned int	use_dma : 1;



	unsigned int	gpio_detect;

	unsigned int	gpio_wprotect;

drivers/mmc/host/Kconfig

+34 −0
Original line number Diff line number Diff line
@@ -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

drivers/mmc/host/s3cmci.c

+31 −8
Original line number Diff line number Diff line
@@ -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;

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