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Commit 16d87782 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl816: introduce struct pcl816_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 d7b8bbb6

drivers/staging/comedi/drivers/pcl816.c

+28 −23
Original line number Diff line number Diff line
@@ -113,13 +113,17 @@ static const struct pcl816_board boardtypes[] = { 
	},

};



struct pcl816_dma_desc {

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

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

};



struct pcl816_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 pcl816_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 ai_poll_ptr;	/*  how many sampes transfer poll */
@@ -152,6 +156,7 @@ static void pcl816_ai_setup_dma(struct comedi_device *dev, 
				struct comedi_subdevice *s)

{

	struct pcl816_private *devpriv = dev->private;

	struct pcl816_dma_desc *dma = &devpriv->dma_desc[0];

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

	unsigned int dma_flags;

	unsigned int bytes;
@@ -172,11 +177,11 @@ static void pcl816_ai_setup_dma(struct comedi_device *dev, 
	} else

		devpriv->dma_runs_to_end = -1;



	devpriv->next_dma_buf = 0;

	devpriv->cur_dma = 0;

	set_dma_mode(devpriv->dma, DMA_MODE_READ);

	dma_flags = claim_dma_lock();

	clear_dma_ff(devpriv->dma);

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

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

	set_dma_count(devpriv->dma, bytes);

	release_dma_lock(dma_flags);

	enable_dma(devpriv->dma);
@@ -187,16 +192,17 @@ static void pcl816_ai_setup_next_dma(struct comedi_device *dev, 
{

	struct pcl816_private *devpriv = dev->private;

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

	struct pcl816_dma_desc *dma;

	unsigned long dma_flags;



	disable_dma(devpriv->dma);

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

		/* switch dma bufs */

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

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

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

		set_dma_mode(devpriv->dma, DMA_MODE_READ);

		dma_flags = claim_dma_lock();

		set_dma_addr(devpriv->dma,

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

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

		if (devpriv->dma_runs_to_end)

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

		else
@@ -318,7 +324,7 @@ static irqreturn_t pcl816_interrupt(int irq, void *d) 
	struct comedi_device *dev = d;

	struct comedi_subdevice *s = dev->read_subdev;

	struct pcl816_private *devpriv = dev->private;

	unsigned short *ptr;

	struct pcl816_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];

	unsigned int bufptr;

	unsigned int len;
@@ -333,15 +339,14 @@ static irqreturn_t pcl816_interrupt(int irq, void *d) 
		return IRQ_HANDLED;

	}



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



	pcl816_ai_setup_next_dma(dev, s);



	len = (devpriv->hwdmasize >> 1) - devpriv->ai_poll_ptr;

	bufptr = devpriv->ai_poll_ptr;

	devpriv->ai_poll_ptr = 0;



	transfer_from_dma_buf(dev, s, ptr, bufptr, len);

	transfer_from_dma_buf(dev, s, (unsigned short *)dma->virt_addr,

			      bufptr, len);



	pcl816_ai_clear_eoc(dev);
@@ -521,6 +526,7 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) 
static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)

{

	struct pcl816_private *devpriv = dev->private;

	struct pcl816_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];

	unsigned long flags;

	unsigned int top1, top2, i;
@@ -546,9 +552,7 @@ static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) 
		return 0;

	}



	transfer_from_dma_buf(dev, s,

			      (unsigned short *)devpriv->dmabuf[devpriv->

								next_dma_buf],

	transfer_from_dma_buf(dev, s, (unsigned short *)dma->virt_addr,

			      devpriv->ai_poll_ptr, top2);



	devpriv->ai_poll_ptr = top1;	/*  new buffer position */
@@ -661,6 +665,7 @@ static int pcl816_alloc_dma(struct comedi_device *dev, 
			    unsigned int irq_num, unsigned int dma_chan)

{

	struct pcl816_private *devpriv = dev->private;

	struct pcl816_dma_desc *dma;

	int i;



	/*
@@ -692,14 +697,12 @@ static int pcl816_alloc_dma(struct comedi_device *dev, 
	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->virt_addr = __get_dma_pages(GFP_KERNEL, devpriv->dmapages);

		if (!dma->virt_addr)

			return -ENOMEM;



		devpriv->dmabuf[i] = dmabuf;

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

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

	}

	return 0;

}
@@ -707,6 +710,7 @@ static int pcl816_alloc_dma(struct comedi_device *dev, 
static void pcl816_free_dma(struct comedi_device *dev)

{

	struct pcl816_private *devpriv = dev->private;

	struct pcl816_dma_desc *dma;

	int i;



	if (!devpriv)
@@ -715,8 +719,9 @@ static void pcl816_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->virt_addr)

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

	}

}