Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
77 lines
1.6 KiB
C
77 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"
|
|
#include "pl080.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);
|
|
}
|