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-rw-r--r--arch/arm/plat-spear/pl080.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/arm/plat-spear/pl080.c b/arch/arm/plat-spear/pl080.c
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--- /dev/null
+++ b/arch/arm/plat-spear/pl080.c
@@ -0,0 +1,80 @@
+/*
+ * 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(struct pl08x_dma_chan *ch)
+{
+ const struct pl08x_channel_data *cd = ch->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(struct pl08x_dma_chan *ch)
+{
+ const struct pl08x_channel_data *cd = ch->cd;
+ unsigned long flags;
+
+ spin_lock_irqsave(&lock, flags);
+
+ /* if signal is not used */
+ if (!signals[cd->min_signal].busy)
+ BUG();
+
+ signals[cd->min_signal].busy--;
+
+ spin_unlock_irqrestore(&lock, flags);
+}