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Commit 38a7d499 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: das16: introduce struct das16_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 ef98a104

drivers/staging/comedi/drivers/das16.c

+26 −22
Original line number Diff line number Diff line
@@ -439,6 +439,11 @@ static inline int timer_period(void) 
	return HZ / 20;

}



struct das16_dma_desc {

	uint16_t *virt_addr;	/* virtual address of DMA buffer */

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

};



struct das16_private_struct {

	unsigned int		clockbase;

	unsigned int		ctrl_reg;
@@ -446,9 +451,8 @@ struct das16_private_struct { 
	unsigned int		divisor1;

	unsigned int		divisor2;

	unsigned int		dma_chan;

	uint16_t		*dma_buffer[2];

	dma_addr_t		dma_buffer_addr[2];

	unsigned int		current_buffer;

	struct das16_dma_desc	dma_desc[2];

	unsigned int		cur_dma;

	unsigned int		dma_transfer_size;

	struct comedi_lrange	*user_ai_range_table;

	struct comedi_lrange	*user_ao_range_table;
@@ -528,11 +532,12 @@ static void das16_interrupt(struct comedi_device *dev) 
	struct comedi_subdevice *s = dev->read_subdev;

	struct comedi_async *async = s->async;

	struct comedi_cmd *cmd = &async->cmd;

	struct das16_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];

	struct das16_dma_desc *nxt_dma;

	unsigned long spin_flags;

	unsigned long dma_flags;

	unsigned int nsamples;

	int num_bytes, residue;

	int buffer_index;



	spin_lock_irqsave(&dev->spinlock, spin_flags);

	if (!(devpriv->ctrl_reg & DAS16_CTRL_DMAE)) {
@@ -558,14 +563,13 @@ static void das16_interrupt(struct comedi_device *dev) 
		async->events |= COMEDI_CB_EOA;

	}



	buffer_index = devpriv->current_buffer;

	devpriv->current_buffer = (devpriv->current_buffer + 1) % 2;

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

	devpriv->adc_byte_count -= num_bytes;



	/*  re-enable  dma */

	if ((async->events & COMEDI_CB_EOA) == 0) {

		set_dma_addr(devpriv->dma_chan,

			     devpriv->dma_buffer_addr[devpriv->current_buffer]);

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

		set_dma_addr(devpriv->dma_chan, nxt_dma->hw_addr);

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

		enable_dma(devpriv->dma_chan);

	}
@@ -574,8 +578,7 @@ static void das16_interrupt(struct comedi_device *dev) 
	spin_unlock_irqrestore(&dev->spinlock, spin_flags);



	nsamples = comedi_bytes_to_samples(s, num_bytes);

	comedi_buf_write_samples(s, devpriv->dma_buffer[buffer_index],

				 nsamples);

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



	comedi_handle_events(dev, s);

}
@@ -746,6 +749,7 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s) 
{

	const struct das16_board *board = dev->board_ptr;

	struct das16_private_struct *devpriv = dev->private;

	struct das16_dma_desc *dma = &devpriv->dma_desc[0];

	struct comedi_async *async = s->async;

	struct comedi_cmd *cmd = &async->cmd;

	unsigned int byte;
@@ -800,9 +804,8 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s) 
	/* clear flip-flop to make sure 2-byte registers for

	 * count and address get set correctly */

	clear_dma_ff(devpriv->dma_chan);

	devpriv->current_buffer = 0;

	set_dma_addr(devpriv->dma_chan,

		     devpriv->dma_buffer_addr[devpriv->current_buffer]);

	devpriv->cur_dma = 0;

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

	devpriv->dma_transfer_size = DAS16_DMA_SIZE;

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

	enable_dma(devpriv->dma_chan);
@@ -1067,13 +1070,13 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it) 


		/* allocate dma buffers */

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

			void *p;

			struct das16_dma_desc *dma = &devpriv->dma_desc[i];



			p = pci_alloc_consistent(NULL, DAS16_DMA_SIZE,

						 &devpriv->dma_buffer_addr[i]);

			if (!p)

			dma->virt_addr = pci_alloc_consistent(NULL,

							      DAS16_DMA_SIZE,

							      &dma->hw_addr);

			if (!dma->virt_addr)

				return -ENOMEM;

			devpriv->dma_buffer[i] = p;

		}



		flags = claim_dma_lock();
@@ -1219,6 +1222,7 @@ static void das16_detach(struct comedi_device *dev) 
{

	const struct das16_board *board = dev->board_ptr;

	struct das16_private_struct *devpriv = dev->private;

	struct das16_dma_desc *dma;

	int i;



	if (devpriv) {
@@ -1228,11 +1232,11 @@ static void das16_detach(struct comedi_device *dev) 
			das16_reset(dev);



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

			if (devpriv->dma_buffer[i])

			dma = &devpriv->dma_desc[i];

			if (dma->virt_addr)

				pci_free_consistent(NULL, DAS16_DMA_SIZE,

						    devpriv->dma_buffer[i],

						    devpriv->

						    dma_buffer_addr[i]);

						    dma->virt_addr,

						    dma->hw_addr);

		}

		if (devpriv->dma_chan)

			free_dma(devpriv->dma_chan);