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Commit eca331c2 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: dt282x: introduce struct dt282x_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 d5702e34

drivers/staging/comedi/drivers/dt282x.c

+53 −58
Original line number Diff line number Diff line
@@ -300,6 +300,12 @@ static const struct dt282x_board boardtypes[] = { 
	},

};



struct dt282x_dma_desc {

	unsigned int chan;	/* DMA channel */

	unsigned short *virt_addr;	/* virtual address of DMA buffer */

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

};



struct dt282x_private {

	unsigned int ad_2scomp:1;
@@ -312,21 +318,16 @@ struct dt282x_private { 
	int ntrig;

	int nread;



	struct {

		int chan;

		unsigned short *buf;	/* DMA buffer */

		int size;	/* size of current transfer */

	} dma[2];

	struct dt282x_dma_desc dma_desc[2];

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

	int current_dma_index;

	int cur_dma;

	int dma_dir;

};



static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)

{

	struct dt282x_private *devpriv = dev->private;

	int dma_chan;

	unsigned long dma_ptr;

	struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];

	unsigned long flags;



	if (!devpriv->ntrig)
@@ -338,18 +339,16 @@ static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n) 
		n = devpriv->ntrig * 2;

	devpriv->ntrig -= n / 2;



	devpriv->dma[dma_index].size = n;

	dma_chan = devpriv->dma[dma_index].chan;

	dma_ptr = virt_to_bus(devpriv->dma[dma_index].buf);

	dma->size = n;



	set_dma_mode(dma_chan, DMA_MODE_READ);

	set_dma_mode(dma->chan, DMA_MODE_READ);

	flags = claim_dma_lock();

	clear_dma_ff(dma_chan);

	set_dma_addr(dma_chan, dma_ptr);

	set_dma_count(dma_chan, n);

	clear_dma_ff(dma->chan);

	set_dma_addr(dma->chan, virt_to_bus(dma->virt_addr));

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

	release_dma_lock(flags);



	enable_dma(dma_chan);

	enable_dma(dma->chan);



	return n;

}
@@ -357,22 +356,19 @@ static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n) 
static int dt282x_prep_ao_dma(struct comedi_device *dev, int dma_index, int n)

{

	struct dt282x_private *devpriv = dev->private;

	int dma_chan;

	unsigned long dma_ptr;

	struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];

	unsigned long flags;



	devpriv->dma[dma_index].size = n;

	dma_chan = devpriv->dma[dma_index].chan;

	dma_ptr = virt_to_bus(devpriv->dma[dma_index].buf);

	dma->size = n;



	set_dma_mode(dma_chan, DMA_MODE_WRITE);

	set_dma_mode(dma->chan, DMA_MODE_WRITE);

	flags = claim_dma_lock();

	clear_dma_ff(dma_chan);

	set_dma_addr(dma_chan, dma_ptr);

	set_dma_count(dma_chan, n);

	clear_dma_ff(dma->chan);

	set_dma_addr(dma->chan, virt_to_bus(dma->virt_addr));

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

	release_dma_lock(flags);



	enable_dma(dma_chan);

	enable_dma(dma->chan);



	return n;

}
@@ -381,8 +377,8 @@ static void dt282x_disable_dma(struct comedi_device *dev) 
{

	struct dt282x_private *devpriv = dev->private;



	disable_dma(devpriv->dma[0].chan);

	disable_dma(devpriv->dma[1].chan);

	disable_dma(devpriv->dma_desc[0].chan);

	disable_dma(devpriv->dma_desc[1].chan);

}



static unsigned int dt282x_ns_to_timer(unsigned int *ns, unsigned int flags)
@@ -444,11 +440,11 @@ static unsigned int dt282x_ao_setup_dma(struct comedi_device *dev, 
					int cur_dma)

{

	struct dt282x_private *devpriv = dev->private;

	void *ptr = devpriv->dma[cur_dma].buf;

	struct dt282x_dma_desc *dma = &devpriv->dma_desc[cur_dma];

	unsigned int nsamples = comedi_bytes_to_samples(s, devpriv->dma_maxsize);

	unsigned int nbytes;



	nbytes = comedi_buf_read_samples(s, ptr, nsamples);

	nbytes = comedi_buf_read_samples(s, dma->virt_addr, nsamples);

	if (nbytes)

		dt282x_prep_ao_dma(dev, cur_dma, nbytes);

	else
@@ -461,39 +457,35 @@ static void dt282x_ao_dma_interrupt(struct comedi_device *dev, 
				    struct comedi_subdevice *s)

{

	struct dt282x_private *devpriv = dev->private;

	int cur_dma = devpriv->current_dma_index;

	struct dt282x_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];



	outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE,

	     dev->iobase + DT2821_SUPCSR_REG);



	disable_dma(devpriv->dma[cur_dma].chan);

	disable_dma(dma->chan);



	devpriv->current_dma_index = 1 - cur_dma;



	if (!dt282x_ao_setup_dma(dev, s, cur_dma))

	if (!dt282x_ao_setup_dma(dev, s, devpriv->cur_dma))

		s->async->events |= COMEDI_CB_OVERFLOW;



	devpriv->cur_dma = 1 - devpriv->cur_dma;

}



static void dt282x_ai_dma_interrupt(struct comedi_device *dev,

				    struct comedi_subdevice *s)

{

	struct dt282x_private *devpriv = dev->private;

	int cur_dma = devpriv->current_dma_index;

	void *ptr = devpriv->dma[cur_dma].buf;

	int size = devpriv->dma[cur_dma].size;

	unsigned int nsamples = comedi_bytes_to_samples(s, size);

	struct dt282x_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];

	unsigned int nsamples = comedi_bytes_to_samples(s, dma->size);

	int ret;



	outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE,

	     dev->iobase + DT2821_SUPCSR_REG);



	disable_dma(devpriv->dma[cur_dma].chan);

	disable_dma(dma->chan);



	devpriv->current_dma_index = 1 - cur_dma;



	dt282x_munge(dev, s, ptr, size);

	ret = comedi_buf_write_samples(s, ptr, nsamples);

	if (ret != size)

	dt282x_munge(dev, s, dma->virt_addr, dma->size);

	ret = comedi_buf_write_samples(s, dma->virt_addr, nsamples);

	if (ret != dma->size)

		return;



	devpriv->nread -= nsamples;
@@ -514,7 +506,9 @@ static void dt282x_ai_dma_interrupt(struct comedi_device *dev, 
	}

#endif

	/* restart the channel */

	dt282x_prep_ai_dma(dev, cur_dma, 0);

	dt282x_prep_ai_dma(dev, devpriv->cur_dma, 0);



	devpriv->cur_dma = 1 - devpriv->cur_dma;

}



static irqreturn_t dt282x_interrupt(int irq, void *d)
@@ -769,7 +763,7 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) 
	devpriv->nread = devpriv->ntrig;



	devpriv->dma_dir = DMA_MODE_READ;

	devpriv->current_dma_index = 0;

	devpriv->cur_dma = 0;

	dt282x_prep_ai_dma(dev, 0, 0);

	if (devpriv->ntrig) {

		dt282x_prep_ai_dma(dev, 1, 0);
@@ -949,7 +943,7 @@ static int dt282x_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s) 
	devpriv->nread = devpriv->ntrig;



	devpriv->dma_dir = DMA_MODE_WRITE;

	devpriv->current_dma_index = 0;

	devpriv->cur_dma = 0;



	outw(devpriv->divisor, dev->iobase + DT2821_TMRCTR_REG);
@@ -1090,10 +1084,11 @@ static int dt282x_alloc_dma(struct comedi_device *dev, 


	devpriv->dma_maxsize = PAGE_SIZE;

	for (i = 0; i < 2; i++) {

		devpriv->dma[i].chan = dma_chan[i];

		devpriv->dma[i].buf =

			(void *)__get_free_page(GFP_KERNEL | GFP_DMA);

		if (!devpriv->dma[i].buf)

		struct dt282x_dma_desc *dma = &devpriv->dma_desc[i];



		dma->chan = dma_chan[i];

		dma->virt_addr = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);

		if (!dma->virt_addr)

			return -ENOMEM;

	}
@@ -1103,18 +1098,18 @@ static int dt282x_alloc_dma(struct comedi_device *dev, 
static void dt282x_free_dma(struct comedi_device *dev)

{

	struct dt282x_private *devpriv = dev->private;

	struct dt282x_dma_desc *dma;

	int i;



	if (!devpriv)

		return;



	for (i = 0; i < 2; i++) {

		if (devpriv->dma[i].chan)

			free_dma(devpriv->dma[i].chan);

		if (devpriv->dma[i].buf)

			free_page((unsigned long)devpriv->dma[i].buf);

		devpriv->dma[i].chan = 0;

		devpriv->dma[i].buf = NULL;

		dma = &devpriv->dma_desc[i];

		if (dma->chan)

			free_dma(dma->chan);

		if (dma->virt_addr)

			free_page((unsigned long)dma->virt_addr);

	}

}