/*
 *  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 <linux/export.h>
#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
 *
 * Return: The current pointer in DMA transfer 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)
		pr_err("ALSA: 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);
ue='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Mark Brown &lt;broonie@kernel.org&gt;</td><td class='right'>2016-07-21 23:53:31 +0100</td></tr>
<tr><th>committer</th><td>Mark Brown &lt;broonie@kernel.org&gt;</td><td class='right'>2016-07-25 11:47:52 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include?id=ef4d96ec4ad947360f48677b6007a4c77953b090'>ef4d96ec4ad947360f48677b6007a4c77953b090</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include?id=ef4d96ec4ad947360f48677b6007a4c77953b090'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=ef4d96ec4ad947360f48677b6007a4c77953b090'>3596ca87c41742a64b444d8c129389298fc30921</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include?id=ef4d96ec4ad947360f48677b6007a4c77953b090'>include</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include?id=f4502dd1da9b060a49d539eb754ff86cb97b89f0'>f4502dd1da9b060a49d539eb754ff86cb97b89f0</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include?id=ef4d96ec4ad947360f48677b6007a4c77953b090&amp;id2=f4502dd1da9b060a49d539eb754ff86cb97b89f0'>diff</a>)</td></tr></table>
<div class='commit-subject'>spi: Split bus and I/O locking</div><div class='commit-msg'>The current SPI code attempts to use bus_lock_mutex for two purposes. One
is to implement spi_bus_lock() which grants exclusive access to the bus.
The other is to serialize access to the physical hardware. This duplicate
purpose causes confusion which leads to cases where access is not locked
when a caller holds the bus lock mutex. Fix this by splitting out the I/O
functionality into a new io_mutex.

This means taking both mutexes in the DMA path, replacing the existing
mutex with the new I/O one in the message pump (the mutex now always
being taken in the message pump) and taking the bus lock mutex in
spi_sync(), allowing __spi_sync() to have no mutex handling.

While we're at it hoist the mutex further up the message pump before we
power up the device so that all power up/down of the block is covered by
it and there are no races with in-line pumping of messages.

Reported-by: Rich Felker &lt;dalias@libc.org&gt;
Tested-by: Rich Felker &lt;dalias@libc.org&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=ef4d96ec4ad947360f48677b6007a4c77953b090'>Diffstat</a> (limited to 'include')</div><table summary='diffstat' class='diffstat'>