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Commit 88dd0c0a authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

staging: comedi: ni_labpc: migrate DMA transfer set-up 



Migrate the code for setting up an ISA DMA transfer into a new function
`labpc_setup_dma()` in the "ni_labpc_isadma" module.  Provide a dummy
inline function in "ni_labpc_isadma.h" if the "ni_labpc_isadma" module
is not being built.

The static function `labpc_suggest_transfer_size()` also needs to move
across to the new module.

Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 50787fa9

drivers/staging/comedi/drivers/ni_labpc.c

+2 −51
Original line number Diff line number Diff line
@@ -387,32 +387,6 @@ static int labpc_ai_insn_read(struct comedi_device *dev, 
	return insn->n;

}



#ifdef CONFIG_ISA_DMA_API

/* utility function that suggests a dma transfer size in bytes */

static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)

{

	unsigned int size;

	unsigned int freq;



	if (cmd->convert_src == TRIG_TIMER)

		freq = 1000000000 / cmd->convert_arg;

	/* return some default value */

	else

		freq = 0xffffffff;



	/* make buffer fill in no more than 1/3 second */

	size = (freq / 3) * sample_size;



	/* set a minimum and maximum size allowed */

	if (size > dma_buffer_size)

		size = dma_buffer_size - dma_buffer_size % sample_size;

	else if (size < sample_size)

		size = sample_size;



	return size;

}

#endif



static bool labpc_use_continuous_mode(const struct comedi_cmd *cmd,

				      enum scan_mode mode)

{
@@ -883,31 +857,8 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) 


	labpc_clear_adc_fifo(dev);



#ifdef CONFIG_ISA_DMA_API

	/*  set up dma transfer */

	if (xfer == isa_dma_transfer) {

		unsigned long irq_flags;



		irq_flags = claim_dma_lock();

		disable_dma(devpriv->dma_chan);

		/* clear flip-flop to make sure 2-byte registers for

		 * count and address get set correctly */

		clear_dma_ff(devpriv->dma_chan);

		set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);

		/*  set appropriate size of transfer */

		devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);

		if (cmd->stop_src == TRIG_COUNT &&

		    devpriv->count * sample_size < devpriv->dma_transfer_size) {

			devpriv->dma_transfer_size =

			    devpriv->count * sample_size;

		}

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

		enable_dma(devpriv->dma_chan);

		release_dma_lock(irq_flags);

		/*  enable board's dma */

		devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);

	}

#endif

	if (xfer == isa_dma_transfer)

		labpc_setup_dma(dev, s);



	/*  enable error interrupts */

	devpriv->cmd3 |= CMD3_ERRINTEN;

drivers/staging/comedi/drivers/ni_labpc_isadma.c

+51 −0
Original line number Diff line number Diff line
@@ -29,6 +29,57 @@ 


/* size in bytes of dma buffer */

static const int dma_buffer_size = 0xff00;

/* 2 bytes per sample */

static const int sample_size = 2;



/* utility function that suggests a dma transfer size in bytes */

static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)

{

	unsigned int size;

	unsigned int freq;



	if (cmd->convert_src == TRIG_TIMER)

		freq = 1000000000 / cmd->convert_arg;

	else

		/* return some default value */

		freq = 0xffffffff;



	/* make buffer fill in no more than 1/3 second */

	size = (freq / 3) * sample_size;



	/* set a minimum and maximum size allowed */

	if (size > dma_buffer_size)

		size = dma_buffer_size - dma_buffer_size % sample_size;

	else if (size < sample_size)

		size = sample_size;



	return size;

}



void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)

{

	struct labpc_private *devpriv = dev->private;

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

	unsigned long irq_flags;



	irq_flags = claim_dma_lock();

	disable_dma(devpriv->dma_chan);

	/* clear flip-flop to make sure 2-byte registers for

	 * count and address get set correctly */

	clear_dma_ff(devpriv->dma_chan);

	set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);

	/* set appropriate size of transfer */

	devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);

	if (cmd->stop_src == TRIG_COUNT &&

	    devpriv->count * sample_size < devpriv->dma_transfer_size)

		devpriv->dma_transfer_size = devpriv->count * sample_size;

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

	enable_dma(devpriv->dma_chan);

	release_dma_lock(irq_flags);

	/* set CMD3 bits for caller to enable DMA and interrupt */

	devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);

}

EXPORT_SYMBOL_GPL(labpc_setup_dma);



int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)

{

drivers/staging/comedi/drivers/ni_labpc_isadma.h

+6 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ static inline bool labpc_have_dma_chan(struct comedi_device *dev) 


int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);

void labpc_free_dma_chan(struct comedi_device *dev);

void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s);



#else
@@ -36,6 +37,11 @@ static inline void labpc_free_dma_chan(struct comedi_device *dev) 
{

}



static inline void labpc_setup_dma(struct comedi_device *dev,

				   struct comedi_subdevice *s)

{

}



#endif



#endif /* _NI_LABPC_ISADMA_H */