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Commit b8e7048b authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl818: introduce struct pcl818_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 665ee190

drivers/staging/comedi/drivers/pcl818.c

+25 −19
Original line number Diff line number Diff line
@@ -302,13 +302,17 @@ static const struct pcl818_board boardtypes[] = { 
	},

};



struct pcl818_dma_desc {

	unsigned long dmabuf;	/*  pointers to begin of DMA buffers */

	unsigned int hwdmaptr;	/*  hardware address of DMA buffers */

};



struct pcl818_private {

	unsigned int dma;	/*  used DMA, 0=don't use DMA */

	unsigned int dmapages;

	unsigned int hwdmasize;

	unsigned long dmabuf[2];	/*  pointers to begin of DMA buffers */

	unsigned int hwdmaptr[2];	/*  hardware address of DMA buffers */

	int next_dma_buf;	/*  which DMA buffer will be used next round */

	struct pcl818_dma_desc dma_desc[2];

	int cur_dma;

	long dma_runs_to_end;	/*  how many we must permorm DMA transfer to end of record */

	unsigned long last_dma_run;	/*  how many bytes we must transfer on last DMA page */

	unsigned int ns_min;	/*  manimal allowed delay between samples (in us) for actual card */
@@ -343,6 +347,7 @@ static void pcl818_ai_setup_dma(struct comedi_device *dev, 
				struct comedi_subdevice *s)

{

	struct pcl818_private *devpriv = dev->private;

	struct pcl818_dma_desc *dma = &devpriv->dma_desc[0];

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

	unsigned int flags;

	unsigned int bytes;
@@ -358,11 +363,11 @@ static void pcl818_ai_setup_dma(struct comedi_device *dev, 
			bytes = devpriv->hwdmasize;

	}



	devpriv->next_dma_buf = 0;

	devpriv->cur_dma = 0;

	set_dma_mode(devpriv->dma, DMA_MODE_READ);

	flags = claim_dma_lock();

	clear_dma_ff(devpriv->dma);

	set_dma_addr(devpriv->dma, devpriv->hwdmaptr[0]);

	set_dma_addr(devpriv->dma, dma->hwdmaptr);

	set_dma_count(devpriv->dma, bytes);

	release_dma_lock(flags);

	enable_dma(devpriv->dma);
@@ -373,16 +378,17 @@ static void pcl818_ai_setup_next_dma(struct comedi_device *dev, 
{

	struct pcl818_private *devpriv = dev->private;

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

	struct pcl818_dma_desc *dma;

	unsigned long flags;



	disable_dma(devpriv->dma);

	devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;

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

	if (devpriv->dma_runs_to_end > -1 || cmd->stop_src == TRIG_NONE) {

		/* switch dma bufs */

		dma = &devpriv->dma_desc[devpriv->cur_dma];

		set_dma_mode(devpriv->dma, DMA_MODE_READ);

		flags = claim_dma_lock();

		set_dma_addr(devpriv->dma,

			     devpriv->hwdmaptr[devpriv->next_dma_buf]);

		set_dma_addr(devpriv->dma, dma->hwdmaptr);

		if (devpriv->dma_runs_to_end || cmd->stop_src == TRIG_NONE)

			set_dma_count(devpriv->dma, devpriv->hwdmasize);

		else
@@ -558,15 +564,14 @@ static void pcl818_handle_dma(struct comedi_device *dev, 
			      struct comedi_subdevice *s)

{

	struct pcl818_private *devpriv = dev->private;

	unsigned short *ptr;

	struct pcl818_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];

	unsigned short *ptr = (unsigned short *)dma->dmabuf;

	unsigned int chan;

	unsigned int val;

	int i, len, bufptr;



	pcl818_ai_setup_next_dma(dev, s);



	ptr = (unsigned short *)devpriv->dmabuf[1 - devpriv->next_dma_buf];



	len = devpriv->hwdmasize >> 1;

	bufptr = 0;
@@ -1057,6 +1062,7 @@ static void pcl818_set_ai_range_table(struct comedi_device *dev, 
static int pcl818_alloc_dma(struct comedi_device *dev, unsigned int dma_chan)

{

	struct pcl818_private *devpriv = dev->private;

	struct pcl818_dma_desc *dma;

	int i;



	if (!(dma_chan == 3 || dma_chan == 1))
@@ -1070,14 +1076,12 @@ static int pcl818_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) 
	devpriv->hwdmasize = (1 << devpriv->dmapages) * PAGE_SIZE;



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

		unsigned long dmabuf;

		dma = &devpriv->dma_desc[i];



		dmabuf = __get_dma_pages(GFP_KERNEL, devpriv->dmapages);

		if (!dmabuf)

		dma->dmabuf = __get_dma_pages(GFP_KERNEL, devpriv->dmapages);

		if (!dma->dmabuf)

			return -ENOMEM;



		devpriv->dmabuf[i] = dmabuf;

		devpriv->hwdmaptr[i] = virt_to_bus((void *)dmabuf);

		dma->hwdmaptr = virt_to_bus((void *)dma->dmabuf);

	}

	return 0;

}
@@ -1085,6 +1089,7 @@ static int pcl818_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) 
static void pcl818_free_dma(struct comedi_device *dev)

{

	struct pcl818_private *devpriv = dev->private;

	struct pcl818_dma_desc *dma;

	int i;



	if (!devpriv)
@@ -1093,8 +1098,9 @@ static void pcl818_free_dma(struct comedi_device *dev) 
	if (devpriv->dma)

		free_dma(devpriv->dma);

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

		if (devpriv->dmabuf[i])

			free_pages(devpriv->dmabuf[i], devpriv->dmapages);

		dma = &devpriv->dma_desc[i];

		if (dma->dmabuf)

			free_pages(dma->dmabuf, devpriv->dmapages);

	}

}