[U-Boot] [PATCH v2 2/2] MIPS: add dma-mapping.h implementation

[Ramon Fried <rfried.dev@gmail.com>]

add implementation for dma_alloc_coherent(),
dma_free_coherent(), dma_map_single() and dma_free_single()

Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
---
v2: fix warning caused by missing casts.

 arch/mips/include/asm/dma-mapping.h | 48 +++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 arch/mips/include/asm/dma-mapping.h

diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
new file mode 100644
index 0000000000..387427c13b
--- /dev/null
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2019
+ * Ramon Fried <rfried.dev@gmail.com>
+ */
+
+#ifndef __ASM_MIPS_DMA_MAPPING_H
+#define __ASM_MIPS_DMA_MAPPING_H
+
+#include <linux/dma-direction.h>
+#include <asm/addrspace.h>
+#define	dma_mapping_error(x, y)	0
+
+static inline void *dma_alloc_coherent(size_t len, unsigned long *handle)
+{
+	void *vaddr = memalign(ARCH_DMA_MINALIGN,
+			       ROUND(len, ARCH_DMA_MINALIGN));
+
+	*handle = CPHYSADDR((unsigned long)vaddr);
+	return (void *)(CKSEG1ADDR((unsigned long)vaddr));
+}
+
+static inline void dma_free_coherent(void *addr)
+{
+	free((void *)CPHYSADDR((unsigned long)addr));
+}
+
+static inline unsigned long dma_map_single(volatile void *vaddr, size_t len,
+					   enum dma_data_direction dir)
+{
+	unsigned long dma_addr = CPHYSADDR((unsigned long)vaddr);
+
+	if (dir == DMA_TO_DEVICE)
+		flush_dcache_range((unsigned long)vaddr,
+				   (unsigned long)vaddr + len);
+	if (dir == DMA_FROM_DEVICE)
+		invalidate_dcache_range((unsigned long)vaddr,
+					(unsigned long)vaddr + len);
+
+	return dma_addr;
+}
+
+static inline void dma_unmap_single(volatile void *vaddr, size_t len,
+				    unsigned long paddr)
+{
+}
+
+#endif /* __ASM_MIPS_DMA_MAPPING_H */
-- 
2.21.0