Commit 71f53ea4 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: mite: move mite_prep_dma() 



For aesthetics, move this functions to a more logical spot in the
code and add a docbook comment for the exported function.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c3c860b3

drivers/staging/comedi/drivers/mite.c

+91 −85
Original line number Diff line number Diff line
@@ -247,91 +247,6 @@ void mite_dma_arm(struct mite_channel *mite_chan) 
}

EXPORT_SYMBOL_GPL(mite_dma_arm);



void mite_prep_dma(struct mite_channel *mite_chan,

		   unsigned int num_device_bits, unsigned int num_memory_bits)

{

	struct mite *mite = mite_chan->mite;

	unsigned int chcr, mcr, dcr, lkcr;



	mite_dma_reset(mite_chan);



	/* short link chaining mode */

	chcr = CHCR_SET_DMA_IE | CHCR_LINKSHORT | CHCR_SET_DONE_IE |

	    CHCR_BURSTEN;

	/*

	 * Link Complete Interrupt: interrupt every time a link

	 * in MITE_RING is completed. This can generate a lot of

	 * extra interrupts, but right now we update the values

	 * of buf_int_ptr and buf_int_count at each interrupt. A

	 * better method is to poll the MITE before each user

	 * "read()" to calculate the number of bytes available.

	 */

	chcr |= CHCR_SET_LC_IE;

	if (num_memory_bits == 32 && num_device_bits == 16) {

		/*

		 * Doing a combined 32 and 16 bit byteswap gets the 16 bit

		 * samples into the fifo in the right order. Tested doing 32 bit

		 * memory to 16 bit device transfers to the analog out of a

		 * pxi-6281, which has mite version = 1, type = 4. This also

		 * works for dma reads from the counters on e-series boards.

		 */

		chcr |= CHCR_BYTE_SWAP_DEVICE | CHCR_BYTE_SWAP_MEMORY;

	}

	if (mite_chan->dir == COMEDI_INPUT)

		chcr |= CHCR_DEV_TO_MEM;



	writel(chcr, mite->mmio + MITE_CHCR(mite_chan->channel));



	/* to/from memory */

	mcr = mite_retry_limit(64) | CR_ASEQUP;

	switch (num_memory_bits) {

	case 8:

		mcr |= CR_PSIZE8;

		break;

	case 16:

		mcr |= CR_PSIZE16;

		break;

	case 32:

		mcr |= CR_PSIZE32;

		break;

	default:

		pr_warn("bug! invalid mem bit width for dma transfer\n");

		break;

	}

	writel(mcr, mite->mmio + MITE_MCR(mite_chan->channel));



	/* from/to device */

	dcr = mite_retry_limit(64) | CR_ASEQUP;

	dcr |= CR_PORTIO | CR_AMDEVICE | mite_drq_reqs(mite_chan->channel);

	switch (num_device_bits) {

	case 8:

		dcr |= CR_PSIZE8;

		break;

	case 16:

		dcr |= CR_PSIZE16;

		break;

	case 32:

		dcr |= CR_PSIZE32;

		break;

	default:

		pr_warn("bug! invalid dev bit width for dma transfer\n");

		break;

	}

	writel(dcr, mite->mmio + MITE_DCR(mite_chan->channel));



	/* reset the DAR */

	writel(0, mite->mmio + MITE_DAR(mite_chan->channel));



	/* the link is 32bits */

	lkcr = mite_retry_limit(64) | CR_ASEQUP | CR_PSIZE32;

	writel(lkcr, mite->mmio + MITE_LKCR(mite_chan->channel));



	/* starting address for link chaining */

	writel(mite_chan->ring->dma_addr,

	       mite->mmio + MITE_LKAR(mite_chan->channel));

}

EXPORT_SYMBOL_GPL(mite_prep_dma);



static u32 mite_device_bytes_transferred(struct mite_channel *mite_chan)

{

	struct mite *mite = mite_chan->mite;
@@ -532,6 +447,97 @@ int mite_done(struct mite_channel *mite_chan) 
}

EXPORT_SYMBOL_GPL(mite_done);



/**

 * mite_prep_dma() - Prepare a MITE dma channel for transfers.

 * @mite_chan: MITE dma channel.

 * @num_device_bits: device transfer size (8, 16, or 32-bits).

 * @num_memory_bits: memory transfer size (8, 16, or 32-bits).

 */

void mite_prep_dma(struct mite_channel *mite_chan,

		   unsigned int num_device_bits, unsigned int num_memory_bits)

{

	struct mite *mite = mite_chan->mite;

	unsigned int chcr, mcr, dcr, lkcr;



	mite_dma_reset(mite_chan);



	/* short link chaining mode */

	chcr = CHCR_SET_DMA_IE | CHCR_LINKSHORT | CHCR_SET_DONE_IE |

	    CHCR_BURSTEN;

	/*

	 * Link Complete Interrupt: interrupt every time a link

	 * in MITE_RING is completed. This can generate a lot of

	 * extra interrupts, but right now we update the values

	 * of buf_int_ptr and buf_int_count at each interrupt. A

	 * better method is to poll the MITE before each user

	 * "read()" to calculate the number of bytes available.

	 */

	chcr |= CHCR_SET_LC_IE;

	if (num_memory_bits == 32 && num_device_bits == 16) {

		/*

		 * Doing a combined 32 and 16 bit byteswap gets the 16 bit

		 * samples into the fifo in the right order. Tested doing 32 bit

		 * memory to 16 bit device transfers to the analog out of a

		 * pxi-6281, which has mite version = 1, type = 4. This also

		 * works for dma reads from the counters on e-series boards.

		 */

		chcr |= CHCR_BYTE_SWAP_DEVICE | CHCR_BYTE_SWAP_MEMORY;

	}

	if (mite_chan->dir == COMEDI_INPUT)

		chcr |= CHCR_DEV_TO_MEM;



	writel(chcr, mite->mmio + MITE_CHCR(mite_chan->channel));



	/* to/from memory */

	mcr = mite_retry_limit(64) | CR_ASEQUP;

	switch (num_memory_bits) {

	case 8:

		mcr |= CR_PSIZE8;

		break;

	case 16:

		mcr |= CR_PSIZE16;

		break;

	case 32:

		mcr |= CR_PSIZE32;

		break;

	default:

		pr_warn("bug! invalid mem bit width for dma transfer\n");

		break;

	}

	writel(mcr, mite->mmio + MITE_MCR(mite_chan->channel));



	/* from/to device */

	dcr = mite_retry_limit(64) | CR_ASEQUP;

	dcr |= CR_PORTIO | CR_AMDEVICE | mite_drq_reqs(mite_chan->channel);

	switch (num_device_bits) {

	case 8:

		dcr |= CR_PSIZE8;

		break;

	case 16:

		dcr |= CR_PSIZE16;

		break;

	case 32:

		dcr |= CR_PSIZE32;

		break;

	default:

		pr_warn("bug! invalid dev bit width for dma transfer\n");

		break;

	}

	writel(dcr, mite->mmio + MITE_DCR(mite_chan->channel));



	/* reset the DAR */

	writel(0, mite->mmio + MITE_DAR(mite_chan->channel));



	/* the link is 32bits */

	lkcr = mite_retry_limit(64) | CR_ASEQUP | CR_PSIZE32;

	writel(lkcr, mite->mmio + MITE_LKCR(mite_chan->channel));



	/* starting address for link chaining */

	writel(mite_chan->ring->dma_addr,

	       mite->mmio + MITE_LKAR(mite_chan->channel));

}

EXPORT_SYMBOL_GPL(mite_prep_dma);



static struct mite_channel *__mite_request_channel(struct mite *mite,

						   struct mite_ring *ring,

						   unsigned int min_channel,

drivers/staging/comedi/drivers/mite.h

+1 −1
Original line number Diff line number Diff line
@@ -68,7 +68,7 @@ void mite_ack_linkc(struct mite_channel *, struct comedi_subdevice *, 
		    bool sync);

int mite_done(struct mite_channel *mite_chan);



void mite_prep_dma(struct mite_channel *mite_chan,

void mite_prep_dma(struct mite_channel *,

		   unsigned int num_device_bits, unsigned int num_memory_bits);



struct mite_channel *mite_request_channel_in_range(struct mite *,

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