Am Mo., 10. Juni 2019 um 20:05 Uhr schrieb 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
this doesn't match all requirements for a generic MIPS DMA interface. It doesn't handle 64 Bit, coherent DMA or different kinds of memory mapping. I would rather fix the macb driver to use existing U-Boot API.
Alternatively you could port the generic dma-mapping.h from Linux so you could either have empty function bodies or an architecture can optionally provide an implementation.