mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-13 14:14:37 +00:00
0fdebc5ec2
Based on the normalized pattern:
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
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference.
Reviewed-by: Allison Randal <allison@lohutok.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* arch/arm/plat-spear/pl080.c
|
|
*
|
|
* DMAC pl080 definitions for SPEAr platform
|
|
*
|
|
* Copyright (C) 2012 ST Microelectronics
|
|
* Viresh Kumar <vireshk@kernel.org>
|
|
*/
|
|
|
|
#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 "spear.h"
|
|
#include "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);
|
|
}
|