Commit 74791a2d authored by Nicolas Ferre's avatar Nicolas Ferre Committed by Linus Torvalds
Browse files

mmc: atmel-mci: new MCI2 module support in atmel-mci driver 



This new revision of the IP adds some improvements to the MCI already
present in several Atmel SOC.

Some new registers are added and a particular way of handling DMA
interaction lead to a new sequence in function call which is backward
compatible: On MCI2, we must set the DMAEN bit to enable the DMA
handshaking interface.  This must happen before the data transfer command
is sent.

A new function is able to differentiate MCI2 code and is based on
knowledge of processor id (cpu_is_xxx()).

Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
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 2635d1ba

drivers/mmc/host/atmel-mci.c

+75 −10
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ struct atmel_mci_dma { 
 * @need_clock_update: Update the clock rate before the next request.

 * @need_reset: Reset controller before next request.

 * @mode_reg: Value of the MR register.

 * @cfg_reg: Value of the CFG register.

 * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus

 *	rate and timeout calculations.

 * @mapbase: Physical address of the MMIO registers.
@@ -157,6 +158,7 @@ struct atmel_mci { 
	bool			need_clock_update;

	bool			need_reset;

	u32			mode_reg;

	u32			cfg_reg;

	unsigned long		bus_hz;

	unsigned long		mapbase;

	struct clk		*mck;
@@ -224,6 +226,19 @@ static bool mci_has_rwproof(void) 
		return true;

}



/*

 * The new MCI2 module isn't 100% compatible with the old MCI module,

 * and it has a few nice features which we want to use...

 */

static inline bool atmci_is_mci2(void)

{

	if (cpu_is_at91sam9g45())

		return true;



	return false;

}





/*

 * The debugfs stuff below is mostly optimized away when

 * CONFIG_DEBUG_FS is not set.
@@ -359,12 +374,33 @@ static int atmci_regs_show(struct seq_file *s, void *v) 
			buf[MCI_BLKR / 4],

			buf[MCI_BLKR / 4] & 0xffff,

			(buf[MCI_BLKR / 4] >> 16) & 0xffff);

	if (atmci_is_mci2())

		seq_printf(s, "CSTOR:\t0x%08x\n", buf[MCI_CSTOR / 4]);



	/* Don't read RSPR and RDR; it will consume the data there */



	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);

	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);



	if (atmci_is_mci2()) {

		u32 val;



		val = buf[MCI_DMA / 4];

		seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",

				val, val & 3,

				((val >> 4) & 3) ?

					1 << (((val >> 4) & 3) + 1) : 1,

				val & MCI_DMAEN ? " DMAEN" : "");



		val = buf[MCI_CFG / 4];

		seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",

				val,

				val & MCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",

				val & MCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",

				val & MCI_CFG_HSMODE ? " HSMODE" : "",

				val & MCI_CFG_LSYNC ? " LSYNC" : "");

	}



	kfree(buf);



	return 0;
@@ -559,6 +595,10 @@ static void atmci_dma_complete(void *arg) 


	dev_vdbg(&host->pdev->dev, "DMA complete\n");



	if (atmci_is_mci2())

		/* Disable DMA hardware handshaking on MCI */

		mci_writel(host, DMA, mci_readl(host, DMA) & ~MCI_DMAEN);



	atmci_dma_cleanup(host);



	/*
@@ -594,7 +634,7 @@ static void atmci_dma_complete(void *arg) 
}



static int

atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)

atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)

{

	struct dma_chan			*chan;

	struct dma_async_tx_descriptor	*desc;
@@ -626,6 +666,9 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data) 
	if (!chan)

		return -ENODEV;



	if (atmci_is_mci2())

		mci_writel(host, DMA, MCI_DMA_CHKSIZE(3) | MCI_DMAEN);



	if (data->flags & MMC_DATA_READ)

		direction = DMA_FROM_DEVICE;

	else
@@ -643,10 +686,6 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data) 
	host->dma.data_desc = desc;

	desc->callback = atmci_dma_complete;

	desc->callback_param = host;

	desc->tx_submit(desc);



	/* Go! */

	chan->device->device_issue_pending(chan);



	return 0;

unmap_exit:
@@ -654,13 +693,26 @@ unmap_exit: 
	return -ENOMEM;

}



static void atmci_submit_data(struct atmel_mci *host)

{

	struct dma_chan			*chan = host->data_chan;

	struct dma_async_tx_descriptor	*desc = host->dma.data_desc;



	if (chan) {

		desc->tx_submit(desc);

		chan->device->device_issue_pending(chan);

	}

}



#else /* CONFIG_MMC_ATMELMCI_DMA */



static int atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)

static int atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)

{

	return -ENOSYS;

}



static void atmci_submit_data(struct atmel_mci *host) {}



static void atmci_stop_dma(struct atmel_mci *host)

{

	/* Data transfer was stopped by the interrupt handler */
@@ -674,7 +726,7 @@ static void atmci_stop_dma(struct atmel_mci *host) 
 * Returns a mask of interrupt flags to be enabled after the whole

 * request has been prepared.

 */

static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data)

static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)

{

	u32 iflags;
@@ -685,7 +737,7 @@ static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data) 
	host->data = data;



	iflags = ATMCI_DATA_ERROR_FLAGS;

	if (atmci_submit_data_dma(host, data)) {

	if (atmci_prepare_data_dma(host, data)) {

		host->data_chan = NULL;



		/*
@@ -731,6 +783,8 @@ static void atmci_start_request(struct atmel_mci *host, 
		mci_writel(host, CR, MCI_CR_SWRST);

		mci_writel(host, CR, MCI_CR_MCIEN);

		mci_writel(host, MR, host->mode_reg);

		if (atmci_is_mci2())

			mci_writel(host, CFG, host->cfg_reg);

		host->need_reset = false;

	}

	mci_writel(host, SDCR, slot->sdc_reg);
@@ -746,6 +800,7 @@ static void atmci_start_request(struct atmel_mci *host, 
		while (!(mci_readl(host, SR) & MCI_CMDRDY))

			cpu_relax();

	}

	iflags = 0;

	data = mrq->data;

	if (data) {

		atmci_set_timeout(host, slot, data);
@@ -755,15 +810,17 @@ static void atmci_start_request(struct atmel_mci *host, 
				| MCI_BLKLEN(data->blksz));

		dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",

			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));



		iflags |= atmci_prepare_data(host, data);

	}



	iflags = MCI_CMDRDY;

	iflags |= MCI_CMDRDY;

	cmd = mrq->cmd;

	cmdflags = atmci_prepare_command(slot->mmc, cmd);

	atmci_start_command(host, cmd, cmdflags);



	if (data)

		iflags |= atmci_submit_data(host, data);

		atmci_submit_data(host);



	if (mrq->stop) {

		host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
@@ -859,6 +916,8 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 
			clk_enable(host->mck);

			mci_writel(host, CR, MCI_CR_SWRST);

			mci_writel(host, CR, MCI_CR_MCIEN);

			if (atmci_is_mci2())

				mci_writel(host, CFG, host->cfg_reg);

		}



		/*
@@ -1097,6 +1156,8 @@ static void atmci_detect_change(unsigned long data) 
				mci_writel(host, CR, MCI_CR_SWRST);

				mci_writel(host, CR, MCI_CR_MCIEN);

				mci_writel(host, MR, host->mode_reg);

				if (atmci_is_mci2())

					mci_writel(host, CFG, host->cfg_reg);



				host->data = NULL;

				host->cmd = NULL;
@@ -1620,6 +1681,10 @@ static void atmci_configure_dma(struct atmel_mci *host) 
	}

	if (!host->dma.chan)

		dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");

	else

		dev_info(&host->pdev->dev,

					"Using %s for DMA transfers\n",

					dma_chan_name(host->dma.chan));

}

#else

static void atmci_configure_dma(struct atmel_mci *host) {}

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