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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/mach-spear/pl080.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mach-spear/pl080.c')
-rw-r--r-- | arch/arm/mach-spear/pl080.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm/mach-spear/pl080.c b/arch/arm/mach-spear/pl080.c new file mode 100644 index 000000000..d6b8627d2 --- /dev/null +++ b/arch/arm/mach-spear/pl080.c @@ -0,0 +1,75 @@ +// 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); +} |