Commit 4d1c15c0 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: ni_labpc: introduce struct labpc_dma_desc 



For aesthetics, introduce a struct to hold the DMA descriptor data.

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 6d262751

drivers/staging/comedi/drivers/ni_labpc.h

+10 −5
Original line number Diff line number Diff line
@@ -34,6 +34,13 @@ struct labpc_boardinfo { 
	unsigned is_labpc1200:1;	/* has extra regs compared to pc+ */

};



struct labpc_dma_desc {

	unsigned int chan;	/* DMA channel */

	u16 *virt_addr;		/* virtual address of DMA buffer */

	phys_addr_t hw_addr;	/* hardware (bus) address of DMA buffer */

	unsigned int size;	/* size of DMA transfer (in bytes) */

};



struct labpc_private {

	/*  number of data points left to be taken */

	unsigned long long count;
@@ -61,11 +68,9 @@ struct labpc_private { 
	 * conversions

	 */

	unsigned int divisor_b1;

	unsigned int dma_chan;	/*  dma channel to use */

	u16 *dma_buffer;	/*  buffer ai will dma into */

	phys_addr_t dma_addr;

	/* transfer size in bytes for current transfer */

	unsigned int dma_transfer_size;



	struct labpc_dma_desc dma_desc;



	/* we are using dma/fifo-half-full/etc. */

	enum transfer_type current_transfer;

	/*

drivers/staging/comedi/drivers/ni_labpc_isadma.c

+30 −28
Original line number Diff line number Diff line
@@ -60,22 +60,23 @@ static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd) 
void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)

{

	struct labpc_private *devpriv = dev->private;

	struct labpc_dma_desc *dma = &devpriv->dma_desc;

	struct comedi_cmd *cmd = &s->async->cmd;

	unsigned long irq_flags;



	irq_flags = claim_dma_lock();

	disable_dma(devpriv->dma_chan);

	disable_dma(dma->chan);

	/* clear flip-flop to make sure 2-byte registers for

	 * count and address get set correctly */

	clear_dma_ff(devpriv->dma_chan);

	set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);

	clear_dma_ff(dma->chan);

	set_dma_addr(dma->chan, dma->hw_addr);

	/* set appropriate size of transfer */

	devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);

	dma->size = labpc_suggest_transfer_size(cmd);

	if (cmd->stop_src == TRIG_COUNT &&

	    devpriv->count * sample_size < devpriv->dma_transfer_size)

		devpriv->dma_transfer_size = devpriv->count * sample_size;

	set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);

	enable_dma(devpriv->dma_chan);

	    devpriv->count * sample_size < dma->size)

		dma->size = devpriv->count * sample_size;

	set_dma_count(dma->chan, dma->size);

	enable_dma(dma->chan);

	release_dma_lock(irq_flags);

	/* set CMD3 bits for caller to enable DMA and interrupt */

	devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
@@ -85,6 +86,7 @@ EXPORT_SYMBOL_GPL(labpc_setup_dma); 
void labpc_drain_dma(struct comedi_device *dev)

{

	struct labpc_private *devpriv = dev->private;

	struct labpc_dma_desc *dma = &devpriv->dma_desc;

	struct comedi_subdevice *s = dev->read_subdev;

	struct comedi_async *async = s->async;

	struct comedi_cmd *cmd = &async->cmd;
@@ -95,18 +97,18 @@ void labpc_drain_dma(struct comedi_device *dev) 
	status = devpriv->stat1;



	flags = claim_dma_lock();

	disable_dma(devpriv->dma_chan);

	disable_dma(dma->chan);

	/* clear flip-flop to make sure 2-byte registers for

	 * count and address get set correctly */

	clear_dma_ff(devpriv->dma_chan);

	clear_dma_ff(dma->chan);



	/* figure out how many points to read */

	max_points = devpriv->dma_transfer_size / sample_size;

	max_points = dma->size / sample_size;

	/* residue is the number of points left to be done on the dma

	 * transfer.  It should always be zero at this point unless

	 * the stop_src is set to external triggering.

	 */

	residue = get_dma_residue(devpriv->dma_chan) / sample_size;

	residue = get_dma_residue(dma->chan) / sample_size;

	num_points = max_points - residue;

	if (cmd->stop_src == TRIG_COUNT && devpriv->count < num_points)

		num_points = devpriv->count;
@@ -114,21 +116,21 @@ void labpc_drain_dma(struct comedi_device *dev) 
	/* figure out how many points will be stored next time */

	leftover = 0;

	if (cmd->stop_src != TRIG_COUNT) {

		leftover = devpriv->dma_transfer_size / sample_size;

		leftover = dma->size / sample_size;

	} else if (devpriv->count > num_points) {

		leftover = devpriv->count - num_points;

		if (leftover > max_points)

			leftover = max_points;

	}



	comedi_buf_write_samples(s, devpriv->dma_buffer, num_points);

	comedi_buf_write_samples(s, dma->virt_addr, num_points);



	if (cmd->stop_src == TRIG_COUNT)

		devpriv->count -= num_points;



	/* set address and count for next transfer */

	set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);

	set_dma_count(devpriv->dma_chan, leftover * sample_size);

	set_dma_addr(dma->chan, dma->hw_addr);

	set_dma_count(dma->chan, leftover * sample_size);

	release_dma_lock(flags);

}

EXPORT_SYMBOL_GPL(labpc_drain_dma);
@@ -136,10 +138,11 @@ EXPORT_SYMBOL_GPL(labpc_drain_dma); 
static void handle_isa_dma(struct comedi_device *dev)

{

	struct labpc_private *devpriv = dev->private;

	struct labpc_dma_desc *dma = &devpriv->dma_desc;



	labpc_drain_dma(dev);



	enable_dma(devpriv->dma_chan);

	enable_dma(dma->chan);



	/* clear dma tc interrupt */

	devpriv->write_byte(dev, 0x1, DMATC_CLEAR_REG);
@@ -163,6 +166,7 @@ EXPORT_SYMBOL_GPL(labpc_handle_dma_status); 
int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)

{

	struct labpc_private *devpriv = dev->private;

	struct labpc_dma_desc *dma = &devpriv->dma_desc;

	void *dma_buffer;

	unsigned long dma_flags;

	int ret;
@@ -180,13 +184,13 @@ int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan) 
		return ret;

	}



	devpriv->dma_buffer = dma_buffer;

	devpriv->dma_chan = dma_chan;

	devpriv->dma_addr = virt_to_bus(devpriv->dma_buffer);

	dma->virt_addr = dma_buffer;

	dma->chan = dma_chan;

	dma->hw_addr = virt_to_bus(dma->virt_addr);



	dma_flags = claim_dma_lock();

	disable_dma(devpriv->dma_chan);

	set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);

	disable_dma(dma->chan);

	set_dma_mode(dma->chan, DMA_MODE_READ);

	release_dma_lock(dma_flags);



	return 0;
@@ -196,13 +200,11 @@ EXPORT_SYMBOL_GPL(labpc_init_dma_chan); 
void labpc_free_dma_chan(struct comedi_device *dev)

{

	struct labpc_private *devpriv = dev->private;

	struct labpc_dma_desc *dma = &devpriv->dma_desc;



	kfree(devpriv->dma_buffer);

	devpriv->dma_buffer = NULL;

	if (devpriv->dma_chan) {

		free_dma(devpriv->dma_chan);

		devpriv->dma_chan = 0;

	}

	kfree(dma->virt_addr);

	if (dma->chan)

		free_dma(dma->chan);

}

EXPORT_SYMBOL_GPL(labpc_free_dma_chan);

drivers/staging/comedi/drivers/ni_labpc_isadma.h

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ static inline bool labpc_have_dma_chan(struct comedi_device *dev) 
{

	struct labpc_private *devpriv = dev->private;



	return (bool)devpriv->dma_chan;

	return (bool)devpriv->dma_desc.chan;

}



int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);

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