diff options
| author | Rajeshwari Shinde | 2013-10-08 16:20:06 +0530 |
|---|---|---|
| committer | Jagannadha Sutradharudu Teki | 2013-10-08 18:18:12 +0530 |
| commit | c4a796329d00ce46de6b5afeb1fdabec82830677 (patch) | |
| tree | 01b2274734a04752e2d0fc139de7f3a726721e4b /arch | |
| parent | 120af1572a3647bb87eff2f62dd8f8a919ee71f0 (diff) | |
spi: exynos: Support word transfers
Since SPI register access is so expensive, it is worth transferring data
a word at a time if we can. This complicates the driver unfortunately.
Use the byte-swapping feature to avoid having to convert to/from big
endian in software.
This change increases speed from about 2MB/s to about 4.5MB/s.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari S Shinde <rajeshwari.s@samsung.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/arch-exynos/spi.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/arm/include/asm/arch-exynos/spi.h b/arch/arm/include/asm/arch-exynos/spi.h index fb23aa69c2a..147c1a73043 100644 --- a/arch/arm/include/asm/arch-exynos/spi.h +++ b/arch/arm/include/asm/arch-exynos/spi.h @@ -22,7 +22,7 @@ struct exynos_spi { unsigned int rx_data; /* 0x1c */ unsigned int pkt_cnt; /* 0x20 */ unsigned char reserved2[4]; - unsigned char reserved3[4]; + unsigned int swap_cfg; /* 0x28 */ unsigned int fb_clk; /* 0x2c */ unsigned char padding[0xffd0]; }; @@ -62,5 +62,14 @@ struct exynos_spi { /* Packet Count */ #define SPI_PACKET_CNT_EN (1 << 16) +/* Swap config */ +#define SPI_TX_SWAP_EN (1 << 0) +#define SPI_TX_BYTE_SWAP (1 << 2) +#define SPI_TX_HWORD_SWAP (1 << 3) +#define SPI_TX_BYTE_SWAP (1 << 2) +#define SPI_RX_SWAP_EN (1 << 4) +#define SPI_RX_BYTE_SWAP (1 << 6) +#define SPI_RX_HWORD_SWAP (1 << 7) + #endif /* __ASSEMBLY__ */ #endif |