linux-stable/arch/arm/mach-spear/pl080.c
Arnd Bergmann a7ed099ffc ARM: spear: move all files to mach-spear
There are no conflicting files between the three mach-spear* directories
and plat-spear any more, so we can now move all file to a common
mach-spear directory.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-03-12 17:39:47 +01:00

78 lines
1.8 KiB
C

/*
* arch/arm/plat-spear/pl080.c
*
* DMAC pl080 definitions for SPEAr platform
*
* Copyright (C) 2012 ST Microelectronics
* Viresh Kumar <viresh.linux@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/amba/pl08x.h>
#include <linux/amba/bus.h>
#include <linux/bug.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/spinlock_types.h>
#include <mach/spear.h>
#include <mach/misc_regs.h>
static spinlock_t lock = __SPIN_LOCK_UNLOCKED(x);
struct {
unsigned char busy;
unsigned char val;
} signals[16] = {{0, 0}, };
int pl080_get_signal(const struct pl08x_channel_data *cd)
{
unsigned int signal = cd->min_signal, val;
unsigned long flags;
spin_lock_irqsave(&lock, flags);
/* Return if signal is already acquired by somebody else */
if (signals[signal].busy &&
(signals[signal].val != cd->muxval)) {
spin_unlock_irqrestore(&lock, flags);
return -EBUSY;
}
/* If acquiring for the first time, configure it */
if (!signals[signal].busy) {
val = readl(DMA_CHN_CFG);
/*
* Each request line has two bits in DMA_CHN_CFG register. To
* goto the bits of current request line, do left shift of
* value by 2 * signal number.
*/
val &= ~(0x3 << (signal * 2));
val |= cd->muxval << (signal * 2);
writel(val, DMA_CHN_CFG);
}
signals[signal].busy++;
signals[signal].val = cd->muxval;
spin_unlock_irqrestore(&lock, flags);
return signal;
}
void pl080_put_signal(const struct pl08x_channel_data *cd, int signal)
{
unsigned long flags;
spin_lock_irqsave(&lock, flags);
/* if signal is not used */
if (!signals[signal].busy)
BUG();
signals[signal].busy--;
spin_unlock_irqrestore(&lock, flags);
}