[net-next-2.6.git] / sound / core / isadma.c

/*
 *  ISA DMA support functions
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

/*
 * Defining following add some delay. Maybe this helps for some broken
 * ISA DMA controllers.
 */

#undef HAVE_REALLY_SLOW_DMA_CONTROLLER

#include <sound/core.h>
#include <asm/dma.h>

/**
 * snd_dma_program - program an ISA DMA transfer
 * @dma: the dma number
 * @addr: the physical address of the buffer
 * @size: the DMA transfer size
 * @mode: the DMA transfer mode, DMA_MODE_XXX
 *
 * Programs an ISA DMA transfer for the given buffer.
 */
void snd_dma_program(unsigned long dma,
		     unsigned long addr, unsigned int size,
                     unsigned short mode)
{
	unsigned long flags;

	flags = claim_dma_lock();
	disable_dma(dma);
	clear_dma_ff(dma);
	set_dma_mode(dma, mode);
	set_dma_addr(dma, addr);
	set_dma_count(dma, size);
	if (!(mode & DMA_MODE_NO_ENABLE))
		enable_dma(dma);
	release_dma_lock(flags);
}

EXPORT_SYMBOL(snd_dma_program);

/**
 * snd_dma_disable - stop the ISA DMA transfer
 * @dma: the dma number
 *
 * Stops the ISA DMA transfer.
 */
void snd_dma_disable(unsigned long dma)
{
	unsigned long flags;

	flags = claim_dma_lock();
	clear_dma_ff(dma);
	disable_dma(dma);
	release_dma_lock(flags);
}

EXPORT_SYMBOL(snd_dma_disable);

/**
 * snd_dma_pointer - return the current pointer to DMA transfer buffer in bytes
 * @dma: the dma number
 * @size: the dma transfer size
 *
 * Returns the current pointer in DMA tranfer buffer in bytes
 */
unsigned int snd_dma_pointer(unsigned long dma, unsigned int size)
{
	unsigned long flags;
	unsigned int result, result1;

	flags = claim_dma_lock();
	clear_dma_ff(dma);
	if (!isa_dma_bridge_buggy)
		disable_dma(dma);
	result = get_dma_residue(dma);
	/*
	 * HACK - read the counter again and choose higher value in order to
	 * avoid reading during counter lower byte roll over if the
	 * isa_dma_bridge_buggy is set.
	 */
	result1 = get_dma_residue(dma);
	if (!isa_dma_bridge_buggy)
		enable_dma(dma);
	release_dma_lock(flags);
	if (unlikely(result < result1))
		result = result1;
#ifdef CONFIG_SND_DEBUG
	if (result > size)
		snd_printk(KERN_ERR "pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size);
#endif
	if (result >= size || result == 0)
		return 0;
	else
		return size - result;
}

EXPORT_SYMBOL(snd_dma_pointer);
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* ISA DMA support functions
c1017a4c	3	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
1da177e4 LT	4	*
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21
	22	/*
	23	* Defining following add some delay. Maybe this helps for some broken
	24	* ISA DMA controllers.
	25	*/
	26
	27	#undef HAVE_REALLY_SLOW_DMA_CONTROLLER
	28
1da177e4 LT	29	#include <sound/core.h>
	30	#include <asm/dma.h>
	31
	32	/**
	33	* snd_dma_program - program an ISA DMA transfer
	34	* @dma: the dma number
	35	* @addr: the physical address of the buffer
	36	* @size: the DMA transfer size
	37	* @mode: the DMA transfer mode, DMA_MODE_XXX
	38	*
	39	* Programs an ISA DMA transfer for the given buffer.
	40	*/
	41	void snd_dma_program(unsigned long dma,
	42	unsigned long addr, unsigned int size,
	43	unsigned short mode)
	44	{
	45	unsigned long flags;
	46
	47	flags = claim_dma_lock();
	48	disable_dma(dma);
	49	clear_dma_ff(dma);
	50	set_dma_mode(dma, mode);
	51	set_dma_addr(dma, addr);
	52	set_dma_count(dma, size);
	53	if (!(mode & DMA_MODE_NO_ENABLE))
	54	enable_dma(dma);
	55	release_dma_lock(flags);
	56	}
	57
c0d3fb39 TI	58	EXPORT_SYMBOL(snd_dma_program);
c0d3fb39 TI	59
1da177e4 LT	60	/**
	61	* snd_dma_disable - stop the ISA DMA transfer
	62	* @dma: the dma number
	63	*
	64	* Stops the ISA DMA transfer.
	65	*/
	66	void snd_dma_disable(unsigned long dma)
	67	{
	68	unsigned long flags;
	69
	70	flags = claim_dma_lock();
	71	clear_dma_ff(dma);
	72	disable_dma(dma);
	73	release_dma_lock(flags);
	74	}
	75
c0d3fb39 TI	76	EXPORT_SYMBOL(snd_dma_disable);
c0d3fb39 TI	77
1da177e4 LT	78	/**
	79	* snd_dma_pointer - return the current pointer to DMA transfer buffer in bytes
	80	* @dma: the dma number
	81	* @size: the dma transfer size
	82	*
	83	* Returns the current pointer in DMA tranfer buffer in bytes
	84	*/
	85	unsigned int snd_dma_pointer(unsigned long dma, unsigned int size)
	86	{
	87	unsigned long flags;
8066e51a	88	unsigned int result, result1;
1da177e4 LT	89
	90	flags = claim_dma_lock();
	91	clear_dma_ff(dma);
	92	if (!isa_dma_bridge_buggy)
	93	disable_dma(dma);
	94	result = get_dma_residue(dma);
8066e51a KH	95	/*
	96	* HACK - read the counter again and choose higher value in order to
	97	* avoid reading during counter lower byte roll over if the
	98	* isa_dma_bridge_buggy is set.
	99	*/
	100	result1 = get_dma_residue(dma);
1da177e4 LT	101	if (!isa_dma_bridge_buggy)
	102	enable_dma(dma);
	103	release_dma_lock(flags);
8066e51a KH	104	if (unlikely(result < result1))
8066e51a KH	105	result = result1;
1da177e4 LT	106	#ifdef CONFIG_SND_DEBUG
	107	if (result > size)
	108	snd_printk(KERN_ERR "pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size);
	109	#endif
	110	if (result >= size \|\| result == 0)
	111	return 0;
	112	else
	113	return size - result;
	114	}
c0d3fb39 TI	115
c0d3fb39 TI	116	EXPORT_SYMBOL(snd_dma_pointer);