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-rw-r--r--arch/arm/include/asm/dma.h149
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma.h b/arch/arm/include/asm/dma.h
new file mode 100644
index 0000000000..e2a1916013
--- /dev/null
+++ b/arch/arm/include/asm/dma.h
@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_ARM_DMA_H
+#define __ASM_ARM_DMA_H
+
+/*
+ * This is the maximum virtual address which can be DMA'd from.
+ */
+#ifndef CONFIG_ZONE_DMA
+#define MAX_DMA_ADDRESS 0xffffffffUL
+#else
+#define MAX_DMA_ADDRESS ({ \
+ extern phys_addr_t arm_dma_zone_size; \
+ arm_dma_zone_size && arm_dma_zone_size < (0x100000000ULL - PAGE_OFFSET) ? \
+ (PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; })
+
+extern phys_addr_t arm_dma_limit;
+#define ARCH_LOW_ADDRESS_LIMIT arm_dma_limit
+#endif
+
+#ifdef CONFIG_ISA_DMA_API
+/*
+ * This is used to support drivers written for the x86 ISA DMA API.
+ * It should not be re-used except for that purpose.
+ */
+#include <linux/spinlock.h>
+#include <linux/scatterlist.h>
+
+#include <mach/isa-dma.h>
+
+/*
+ * The DMA modes reflect the settings for the ISA DMA controller
+ */
+#define DMA_MODE_MASK 0xcc
+
+#define DMA_MODE_READ 0x44
+#define DMA_MODE_WRITE 0x48
+#define DMA_MODE_CASCADE 0xc0
+#define DMA_AUTOINIT 0x10
+
+extern raw_spinlock_t dma_spin_lock;
+
+static inline unsigned long claim_dma_lock(void)
+{
+ unsigned long flags;
+ raw_spin_lock_irqsave(&dma_spin_lock, flags);
+ return flags;
+}
+
+static inline void release_dma_lock(unsigned long flags)
+{
+ raw_spin_unlock_irqrestore(&dma_spin_lock, flags);
+}
+
+/* Clear the 'DMA Pointer Flip Flop'.
+ * Write 0 for LSB/MSB, 1 for MSB/LSB access.
+ */
+#define clear_dma_ff(chan)
+
+/* Set only the page register bits of the transfer address.
+ *
+ * NOTE: This is an architecture specific function, and should
+ * be hidden from the drivers
+ */
+extern void set_dma_page(unsigned int chan, char pagenr);
+
+/* Request a DMA channel
+ *
+ * Some architectures may need to do allocate an interrupt
+ */
+extern int request_dma(unsigned int chan, const char * device_id);
+
+/* Free a DMA channel
+ *
+ * Some architectures may need to do free an interrupt
+ */
+extern void free_dma(unsigned int chan);
+
+/* Enable DMA for this channel
+ *
+ * On some architectures, this may have other side effects like
+ * enabling an interrupt and setting the DMA registers.
+ */
+extern void enable_dma(unsigned int chan);
+
+/* Disable DMA for this channel
+ *
+ * On some architectures, this may have other side effects like
+ * disabling an interrupt or whatever.
+ */
+extern void disable_dma(unsigned int chan);
+
+/* Test whether the specified channel has an active DMA transfer
+ */
+extern int dma_channel_active(unsigned int chan);
+
+/* Set the DMA scatter gather list for this channel
+ *
+ * This should not be called if a DMA channel is enabled,
+ * especially since some DMA architectures don't update the
+ * DMA address immediately, but defer it to the enable_dma().
+ */
+extern void set_dma_sg(unsigned int chan, struct scatterlist *sg, int nr_sg);
+
+/* Set the DMA address for this channel
+ *
+ * This should not be called if a DMA channel is enabled,
+ * especially since some DMA architectures don't update the
+ * DMA address immediately, but defer it to the enable_dma().
+ */
+extern void __set_dma_addr(unsigned int chan, void *addr);
+#define set_dma_addr(chan, addr) \
+ __set_dma_addr(chan, (void *)isa_bus_to_virt(addr))
+
+/* Set the DMA byte count for this channel
+ *
+ * This should not be called if a DMA channel is enabled,
+ * especially since some DMA architectures don't update the
+ * DMA count immediately, but defer it to the enable_dma().
+ */
+extern void set_dma_count(unsigned int chan, unsigned long count);
+
+/* Set the transfer direction for this channel
+ *
+ * This should not be called if a DMA channel is enabled,
+ * especially since some DMA architectures don't update the
+ * DMA transfer direction immediately, but defer it to the
+ * enable_dma().
+ */
+extern void set_dma_mode(unsigned int chan, unsigned int mode);
+
+/* Set the transfer speed for this channel
+ */
+extern void set_dma_speed(unsigned int chan, int cycle_ns);
+
+/* Get DMA residue count. After a DMA transfer, this
+ * should return zero. Reading this while a DMA transfer is
+ * still in progress will return unpredictable results.
+ * If called before the channel has been used, it may return 1.
+ * Otherwise, it returns the number of _bytes_ left to transfer.
+ */
+extern int get_dma_residue(unsigned int chan);
+
+#ifndef NO_DMA
+#define NO_DMA 255
+#endif
+
+#endif /* CONFIG_ISA_DMA_API */
+
+#endif /* __ASM_ARM_DMA_H */