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Commit d8332a68 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl812: introduce struct pcl812_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 91ac6981

drivers/staging/comedi/drivers/pcl812.c

+50 −50
Original line number Diff line number Diff line
@@ -506,6 +506,12 @@ static const struct pcl812_board boardtypes[] = { 
	},

};



struct pcl812_dma_desc {

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

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

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

};



struct pcl812_private {

	unsigned char dma;	/*  >0 use dma ( usedDMA channel) */

	unsigned char range_correction;	/*  =1 we must add 1 to range number */
@@ -514,10 +520,8 @@ struct pcl812_private { 
	unsigned int ai_poll_ptr;	/*  how many sampes transfer poll */

	unsigned int dmapages;

	unsigned int hwdmasize;

	unsigned long dmabuf[2];	/*  PTR to DMA buf */

	unsigned int hwdmaptr[2];	/*  HW PTR to DMA buf */

	unsigned int dmabytestomove[2];	/*  how many bytes DMA transfer */

	int next_dma_buf;	/*  which buffer is next to use */

	struct pcl812_dma_desc dma_desc[2];

	int cur_dma;

	unsigned int dma_runs_to_end;	/*  how many times we must switch DMA buffers */

	unsigned int last_dma_run;	/*  how many bytes to transfer on last DMA buffer */

	unsigned int max_812_ai_mode0_rangewait;	/*  setling time for gain */
@@ -549,23 +553,23 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev, 
				struct comedi_subdevice *s)

{

	struct pcl812_private *devpriv = dev->private;

	struct pcl812_dma_desc *dma0 = &devpriv->dma_desc[0];

	struct pcl812_dma_desc *dma1 = &devpriv->dma_desc[1];

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

	unsigned int dma_flags;

	unsigned int bytes;



	/*  we use EOS, so adapt DMA buffer to one scan */

	if (devpriv->ai_eos) {

		devpriv->dmabytestomove[0] = comedi_bytes_per_scan(s);

		devpriv->dmabytestomove[1] = comedi_bytes_per_scan(s);

		dma0->size = comedi_bytes_per_scan(s);

		dma1->size = comedi_bytes_per_scan(s);

		devpriv->dma_runs_to_end = 1;

	} else {

		devpriv->dmabytestomove[0] = devpriv->hwdmasize;

		devpriv->dmabytestomove[1] = devpriv->hwdmasize;

		dma0->size = devpriv->hwdmasize;

		dma1->size = devpriv->hwdmasize;

		if (s->async->prealloc_bufsz < devpriv->hwdmasize) {

			devpriv->dmabytestomove[0] =

				s->async->prealloc_bufsz;

			devpriv->dmabytestomove[1] =

				s->async->prealloc_bufsz;

			dma0->size = s->async->prealloc_bufsz;

			dma1->size = s->async->prealloc_bufsz;

		}

		if (cmd->stop_src == TRIG_NONE) {

			devpriv->dma_runs_to_end = 1;
@@ -574,32 +578,29 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev, 
			bytes = cmd->stop_arg * comedi_bytes_per_scan(s);



			/*  how many DMA pages we must fill */

			devpriv->dma_runs_to_end =

				bytes / devpriv->dmabytestomove[0];

			devpriv->dma_runs_to_end = bytes / dma0->size;



			/* on last dma transfer must be moved */

			devpriv->last_dma_run =

				bytes % devpriv->dmabytestomove[0];

			devpriv->last_dma_run = bytes % dma0->size;

			if (devpriv->dma_runs_to_end == 0)

				devpriv->dmabytestomove[0] =

					devpriv->last_dma_run;

				dma0->size = devpriv->last_dma_run;

			devpriv->dma_runs_to_end--;

		}

	}

	if (devpriv->dmabytestomove[0] > devpriv->hwdmasize) {

		devpriv->dmabytestomove[0] = devpriv->hwdmasize;

	if (dma0->size > devpriv->hwdmasize) {

		dma0->size = devpriv->hwdmasize;

		devpriv->ai_eos = 0;

	}

	if (devpriv->dmabytestomove[1] > devpriv->hwdmasize) {

		devpriv->dmabytestomove[1] = devpriv->hwdmasize;

	if (dma1->size > devpriv->hwdmasize) {

		dma1->size = devpriv->hwdmasize;

		devpriv->ai_eos = 0;

	}

	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_count(devpriv->dma, devpriv->dmabytestomove[0]);

	set_dma_addr(devpriv->dma, dma0->hw_addr);

	set_dma_count(devpriv->dma, dma0->size);

	release_dma_lock(dma_flags);

	enable_dma(devpriv->dma);

}
@@ -608,21 +609,20 @@ static void pcl812_ai_setup_next_dma(struct comedi_device *dev, 
				     struct comedi_subdevice *s)

{

	struct pcl812_private *devpriv = dev->private;

	struct pcl812_dma_desc *dma;

	unsigned long dma_flags;



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

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

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

	disable_dma(devpriv->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->ai_eos) {

		set_dma_count(devpriv->dma,

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

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

	} else {

		if (devpriv->dma_runs_to_end) {

			set_dma_count(devpriv->dma,

				      devpriv->dmabytestomove[devpriv->

							      next_dma_buf]);

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

		} else {

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

		}
@@ -895,19 +895,17 @@ static void pcl812_handle_dma(struct comedi_device *dev, 
			      struct comedi_subdevice *s)

{

	struct pcl812_private *devpriv = dev->private;

	int len, bufptr;

	unsigned short *ptr;



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

	len = (devpriv->dmabytestomove[devpriv->next_dma_buf] >> 1) -

	    devpriv->ai_poll_ptr;

	struct pcl812_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];

	unsigned int nsamples;

	int bufptr;



	pcl812_ai_setup_next_dma(dev, s);



	nsamples = comedi_bytes_to_samples(s, dma->size) - 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, (void *)dma->virt_addr, bufptr, nsamples);

}



static irqreturn_t pcl812_interrupt(int irq, void *d)
@@ -935,6 +933,7 @@ static irqreturn_t pcl812_interrupt(int irq, void *d) 
static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)

{

	struct pcl812_private *devpriv = dev->private;

	struct pcl812_dma_desc *dma;

	unsigned long flags;

	unsigned int top1, top2, i;
@@ -956,7 +955,8 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) 
		return 0;

	}

	/*  where is now DMA in buffer */

	top1 = devpriv->dmabytestomove[1 - devpriv->next_dma_buf] - top1;

	dma = &devpriv->dma_desc[1 - devpriv->cur_dma];

	top1 = dma->size - top1;

	top1 >>= 1;		/*  sample position */

	top2 = top1 - devpriv->ai_poll_ptr;

	if (top2 < 1) {		/*  no new samples */
@@ -964,9 +964,7 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) 
		return 0;

	}



	transfer_from_dma_buf(dev, s,

			      (void *)devpriv->dmabuf[1 -

						      devpriv->next_dma_buf],

	transfer_from_dma_buf(dev, s, (void *)dma->virt_addr,

			      devpriv->ai_poll_ptr, top2);



	devpriv->ai_poll_ptr = top1;	/*  new buffer position */
@@ -1195,6 +1193,7 @@ static void pcl812_set_ai_range_table(struct comedi_device *dev, 
static int pcl812_alloc_dma(struct comedi_device *dev, unsigned int dma_chan)

{

	struct pcl812_private *devpriv = dev->private;

	struct pcl812_dma_desc *dma;

	int i;



	if (!(dma_chan == 3 || dma_chan == 1))
@@ -1208,14 +1207,13 @@ static int pcl812_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->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;

}
@@ -1223,14 +1221,16 @@ static int pcl812_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) 
static void pcl812_free_dma(struct comedi_device *dev)

{

	struct pcl812_private *devpriv = dev->private;

	struct pcl812_dma_desc *dma;

	int i;



	if (!devpriv)

		return;



	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);

	}

	if (devpriv->dma)

		free_dma(devpriv->dma);