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Commit 86aff4bb authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
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staging: comedi: ni_labpc: migrate DMA channel init & free 



Migrate the code for requesting an ISA DMA channel and a DMA buffer, and
the code for freeing them into two new functions in the
"ni_labpc_isadma" module: `labpc_init_dma_chan()` and
`labpc_free_dma_chan()`.  Dummy inline functions are provided in
"ni_labpc_isadma.h" if the "ni_labpc_isadma" module is not being built.

Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9a638662

drivers/staging/comedi/drivers/ni_labpc.c

+5 −30
Original line number Diff line number Diff line
@@ -1708,31 +1708,8 @@ static int labpc_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	if (ret)

		return ret;



#ifdef CONFIG_ISA_DMA_API

	if (dev->irq && (dma_chan == 1 || dma_chan == 3)) {

		void *dma_buffer = kmalloc(dma_buffer_size,

					   GFP_KERNEL | GFP_DMA);



		if (dma_buffer) {

			ret = request_dma(dma_chan, dev->board_name);

			if (ret == 0) {

				unsigned long dma_flags;



				devpriv->dma_buffer = dma_buffer;

				devpriv->dma_chan = dma_chan;

				devpriv->dma_addr =

					virt_to_bus(devpriv->dma_buffer);



				dma_flags = claim_dma_lock();

				disable_dma(devpriv->dma_chan);

				set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);

				release_dma_lock(dma_flags);

			} else {

				kfree(dma_buffer);

			}

		}

	}

#endif

	if (dev->irq)

		labpc_init_dma_chan(dev, dma_chan);



	return 0;

}
@@ -1741,11 +1718,9 @@ static void labpc_detach(struct comedi_device *dev) 
{

	struct labpc_private *devpriv = dev->private;



	if (devpriv) {

		kfree(devpriv->dma_buffer);

		if (devpriv->dma_chan)

			free_dma(devpriv->dma_chan);

	}

	if (devpriv)

		labpc_free_dma_chan(dev);



	comedi_legacy_detach(dev);

}

drivers/staging/comedi/drivers/ni_labpc_isadma.c

+54 −0
Original line number Diff line number Diff line
@@ -18,9 +18,63 @@ 
 */



#include <linux/module.h>

#include <linux/slab.h>

#include "../comedidev.h"



#include <asm/dma.h>



#include "ni_labpc.h"

#include "ni_labpc_isadma.h"



/* size in bytes of dma buffer */

static const int dma_buffer_size = 0xff00;



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

{

	struct labpc_private *devpriv = dev->private;

	void *dma_buffer;

	unsigned long dma_flags;

	int ret;



	if (dma_chan != 1 && dma_chan != 3)

		return -EINVAL;



	dma_buffer = kmalloc(dma_buffer_size, GFP_KERNEL | GFP_DMA);

	if (!dma_buffer)

		return -ENOMEM;



	ret = request_dma(dma_chan, dev->board_name);

	if (ret) {

		kfree(dma_buffer);

		return ret;

	}



	devpriv->dma_buffer = dma_buffer;

	devpriv->dma_chan = dma_chan;

	devpriv->dma_addr = virt_to_bus(devpriv->dma_buffer);



	dma_flags = claim_dma_lock();

	disable_dma(devpriv->dma_chan);

	set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);

	release_dma_lock(dma_flags);



	return 0;

}

EXPORT_SYMBOL_GPL(labpc_init_dma_chan);



void labpc_free_dma_chan(struct comedi_device *dev)

{

	struct labpc_private *devpriv = dev->private;



	kfree(devpriv->dma_buffer);

	devpriv->dma_buffer = NULL;

	if (devpriv->dma_chan) {

		free_dma(devpriv->dma_chan);

		devpriv->dma_chan = 0;

	}

}

EXPORT_SYMBOL_GPL(labpc_free_dma_chan);



static int __init ni_labpc_isadma_init_module(void)

{

	return 0;

drivers/staging/comedi/drivers/ni_labpc_isadma.h

+13 −0
Original line number Diff line number Diff line
@@ -9,8 +9,21 @@ 


#if NI_LABPC_HAVE_ISA_DMA



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

void labpc_free_dma_chan(struct comedi_device *dev);



#else



static inline int labpc_init_dma_chan(struct comedi_device *dev,

				      unsigned int dma_chan)

{

	return -ENOTSUPP;

}



static inline void labpc_free_dma_chan(struct comedi_device *dev)

{

}



#endif



#endif /* _NI_LABPC_ISADMA_H */