u-boot/arch/arm/include/asm/arch-exynos/spi.h
Rajeshwari Shinde c4a796329d 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>
2013-10-08 18:18:12 +05:30

75 lines
1.8 KiB
C

/*
* (C) Copyright 2012 SAMSUNG Electronics
* Padmavathi Venna <padma.v@samsung.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef __ASM_ARCH_EXYNOS_COMMON_SPI_H_
#define __ASM_ARCH_EXYNOS_COMMON_SPI_H_
#ifndef __ASSEMBLY__
/* SPI peripheral register map; padded to 64KB */
struct exynos_spi {
unsigned int ch_cfg; /* 0x00 */
unsigned char reserved0[4];
unsigned int mode_cfg; /* 0x08 */
unsigned int cs_reg; /* 0x0c */
unsigned char reserved1[4];
unsigned int spi_sts; /* 0x14 */
unsigned int tx_data; /* 0x18 */
unsigned int rx_data; /* 0x1c */
unsigned int pkt_cnt; /* 0x20 */
unsigned char reserved2[4];
unsigned int swap_cfg; /* 0x28 */
unsigned int fb_clk; /* 0x2c */
unsigned char padding[0xffd0];
};
#define EXYNOS_SPI_MAX_FREQ 50000000
#define SPI_TIMEOUT_MS 10
/* SPI_CHCFG */
#define SPI_CH_HS_EN (1 << 6)
#define SPI_CH_RST (1 << 5)
#define SPI_SLAVE_MODE (1 << 4)
#define SPI_CH_CPOL_L (1 << 3)
#define SPI_CH_CPHA_B (1 << 2)
#define SPI_RX_CH_ON (1 << 1)
#define SPI_TX_CH_ON (1 << 0)
/* SPI_MODECFG */
#define SPI_MODE_CH_WIDTH_WORD (0x2 << 29)
#define SPI_MODE_BUS_WIDTH_WORD (0x2 << 17)
/* SPI_CSREG */
#define SPI_SLAVE_SIG_INACT (1 << 0)
/* SPI_STS */
#define SPI_ST_TX_DONE (1 << 25)
#define SPI_FIFO_LVL_MASK 0x1ff
#define SPI_TX_LVL_OFFSET 6
#define SPI_RX_LVL_OFFSET 15
/* Feedback Delay */
#define SPI_CLK_BYPASS (0 << 0)
#define SPI_FB_DELAY_90 (1 << 0)
#define SPI_FB_DELAY_180 (2 << 0)
#define SPI_FB_DELAY_270 (3 << 0)
/* 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