diff options
Diffstat (limited to 'package/uboot-ar71xx/files/drivers/spi/ar71xx_spi.c')
| -rw-r--r-- | package/uboot-ar71xx/files/drivers/spi/ar71xx_spi.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/package/uboot-ar71xx/files/drivers/spi/ar71xx_spi.c b/package/uboot-ar71xx/files/drivers/spi/ar71xx_spi.c new file mode 100644 index 000000000..bbe27b16e --- /dev/null +++ b/package/uboot-ar71xx/files/drivers/spi/ar71xx_spi.c @@ -0,0 +1,191 @@ +/* + * (C) Copyright 2010 + * Michael Kurz <michi.kurz@googlemail.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <malloc.h> +#include <spi.h> + +#include <asm/addrspace.h> +#include <asm/types.h> +#include <asm/ar71xx.h> + +/*----------------------------------------------------------------------- + * Definitions + */ + +#ifdef DEBUG_SPI +#define PRINTD(fmt,args...) printf (fmt ,##args) +#else +#define PRINTD(fmt,args...) +#endif + +struct ar71xx_spi_slave { + struct spi_slave slave; + unsigned int mode; +}; + +static inline struct ar71xx_spi_slave *to_ar71xx_spi(struct spi_slave *slave) +{ + return container_of(slave, struct ar71xx_spi_slave, slave); +} + +/*=====================================================================*/ +/* Public Functions */ +/*=====================================================================*/ + +/*----------------------------------------------------------------------- + * Initialization + */ + +void spi_init() +{ + PRINTD("ar71xx_spi: spi_init"); + + // Init SPI Hardware, disable remap, set clock + __raw_writel(0x43, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_CTRL)); + + PRINTD(" ---> out\n"); +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct ar71xx_spi_slave *ss; + + PRINTD("ar71xx_spi: spi_setup_slave"); + + if ((bus != 0) || (cs > 2)) + return NULL; + + ss = malloc(sizeof(struct ar71xx_spi_slave)); + if (!ss) + return NULL; + + ss->slave.bus = bus; + ss->slave.cs = cs; + ss->mode = mode; + + /* TODO: Use max_hz to limit the SCK rate */ + + PRINTD(" ---> out\n"); + + return &ss->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct ar71xx_spi_slave *ss = to_ar71xx_spi(slave); + + free(ss); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + struct ar71xx_spi_slave *ss = to_ar71xx_spi(slave); + uint8_t *rx = din; + const uint8_t *tx = dout; + uint8_t curbyte, curbitlen, restbits; + uint32_t bytes = bitlen / 8; + uint32_t out; + uint32_t in; + + PRINTD("ar71xx_spi: spi_xfer: slave:%p bitlen:%08x dout:%p din:%p flags:%08x\n", slave, bitlen, dout, din, flags); + + if (flags & SPI_XFER_BEGIN) { + __raw_writel(SPI_FS_GPIO, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_FS)); + __raw_writel(SPI_IOC_CS_ALL, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); + } + + restbits = (bitlen % 8); + if (restbits != 0) + bytes++; + + // enable chip select + out = SPI_IOC_CS_ALL & ~(SPI_IOC_CS(slave->cs)); + + while (bytes--) { + + curbyte = 0; + if (tx) { + curbyte = *tx++; + } + + if (restbits != 0) { + curbitlen = restbits; + curbyte <<= 8 - restbits; + } else { + curbitlen = 8; + } + + PRINTD("ar71xx_spi: sending: data:%02x length:%d\n", curbyte, curbitlen); + + /* clock starts at inactive polarity */ + for (curbyte <<= (8 - curbitlen); curbitlen; curbitlen--) { + + if (curbyte & (1 << 7)) + out |= SPI_IOC_DO; + else + out &= ~(SPI_IOC_DO); + + /* setup MSB (to slave) on trailing edge */ + __raw_writel(out, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); + + __raw_writel(out | SPI_IOC_CLK, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); + + curbyte <<= 1; + } + + in = __raw_readl(KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_RDS)); + PRINTD("ar71xx_spi: received:%02x\n", in); + + if (rx) { + if (restbits == 0) { + *rx++ = in; + } else { + *rx++ = (in << (8 - restbits)); + } + } + } + + if (flags & SPI_XFER_END) { + __raw_writel(SPI_IOC_CS(slave->cs), KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); + __raw_writel(SPI_IOC_CS_ALL, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC)); + __raw_writel(0, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_FS)); + } + + PRINTD(" ---> out\n"); + + return 0; +} |