diff options
Diffstat (limited to 'drivers/spi/altera_spi.c')
| -rw-r--r-- | drivers/spi/altera_spi.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/drivers/spi/altera_spi.c b/drivers/spi/altera_spi.c new file mode 100644 index 0000000..918b223 --- /dev/null +++ b/drivers/spi/altera_spi.c @@ -0,0 +1,165 @@ +/* + * Altera SPI driver + * + * based on bfin_spi.c + * Copyright (c) 2005-2008 Analog Devices Inc. + * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw> + * + * Licensed under the GPL-2 or later. + */ +#include <common.h> +#include <asm/io.h> +#include <malloc.h> +#include <spi.h> + +#define ALTERA_SPI_RXDATA 0 +#define ALTERA_SPI_TXDATA 4 +#define ALTERA_SPI_STATUS 8 +#define ALTERA_SPI_CONTROL 12 +#define ALTERA_SPI_SLAVE_SEL 20 + +#define ALTERA_SPI_STATUS_ROE_MSK (0x8) +#define ALTERA_SPI_STATUS_TOE_MSK (0x10) +#define ALTERA_SPI_STATUS_TMT_MSK (0x20) +#define ALTERA_SPI_STATUS_TRDY_MSK (0x40) +#define ALTERA_SPI_STATUS_RRDY_MSK (0x80) +#define ALTERA_SPI_STATUS_E_MSK (0x100) + +#define ALTERA_SPI_CONTROL_IROE_MSK (0x8) +#define ALTERA_SPI_CONTROL_ITOE_MSK (0x10) +#define ALTERA_SPI_CONTROL_ITRDY_MSK (0x40) +#define ALTERA_SPI_CONTROL_IRRDY_MSK (0x80) +#define ALTERA_SPI_CONTROL_IE_MSK (0x100) +#define ALTERA_SPI_CONTROL_SSO_MSK (0x400) + +#ifndef CONFIG_SYS_ALTERA_SPI_LIST +#define CONFIG_SYS_ALTERA_SPI_LIST { CONFIG_SYS_SPI_BASE } +#endif + +static ulong altera_spi_base_list[] = CONFIG_SYS_ALTERA_SPI_LIST; + +struct altera_spi_slave { + struct spi_slave slave; + ulong base; +}; +#define to_altera_spi_slave(s) container_of(s, struct altera_spi_slave, slave) + +__attribute__((weak)) +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + return bus < ARRAY_SIZE(altera_spi_base_list) && cs < 32; +} + +__attribute__((weak)) +void spi_cs_activate(struct spi_slave *slave) +{ + struct altera_spi_slave *altspi = to_altera_spi_slave(slave); + writel(1 << slave->cs, altspi->base + ALTERA_SPI_SLAVE_SEL); + writel(ALTERA_SPI_CONTROL_SSO_MSK, altspi->base + ALTERA_SPI_CONTROL); +} + +__attribute__((weak)) +void spi_cs_deactivate(struct spi_slave *slave) +{ + struct altera_spi_slave *altspi = to_altera_spi_slave(slave); + writel(0, altspi->base + ALTERA_SPI_CONTROL); + writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL); +} + +void spi_init(void) +{ +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct altera_spi_slave *altspi; + + if (!spi_cs_is_valid(bus, cs)) + return NULL; + + altspi = malloc(sizeof(*altspi)); + if (!altspi) + return NULL; + + altspi->slave.bus = bus; + altspi->slave.cs = cs; + altspi->base = altera_spi_base_list[bus]; + debug("%s: bus:%i cs:%i base:%lx\n", __func__, + bus, cs, altspi->base); + + return &altspi->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct altera_spi_slave *altspi = to_altera_spi_slave(slave); + free(altspi); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + struct altera_spi_slave *altspi = to_altera_spi_slave(slave); + + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); + writel(0, altspi->base + ALTERA_SPI_CONTROL); + writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL); + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + struct altera_spi_slave *altspi = to_altera_spi_slave(slave); + + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); + writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL); +} + +#ifndef CONFIG_ALTERA_SPI_IDLE_VAL +# define CONFIG_ALTERA_SPI_IDLE_VAL 0xff +#endif + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + struct altera_spi_slave *altspi = to_altera_spi_slave(slave); + /* assume spi core configured to do 8 bit transfers */ + uint bytes = bitlen / 8; + const uchar *txp = dout; + uchar *rxp = din; + + debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__, + slave->bus, slave->cs, bitlen, bytes, flags); + if (bitlen == 0) + goto done; + + if (bitlen % 8) { + flags |= SPI_XFER_END; + goto done; + } + + /* empty read buffer */ + if (readl(altspi->base + ALTERA_SPI_STATUS) & + ALTERA_SPI_STATUS_RRDY_MSK) + readl(altspi->base + ALTERA_SPI_RXDATA); + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(slave); + + while (bytes--) { + uchar d = txp ? *txp++ : CONFIG_ALTERA_SPI_IDLE_VAL; + debug("%s: tx:%x ", __func__, d); + writel(d, altspi->base + ALTERA_SPI_TXDATA); + while (!(readl(altspi->base + ALTERA_SPI_STATUS) & + ALTERA_SPI_STATUS_RRDY_MSK)) + ; + d = readl(altspi->base + ALTERA_SPI_RXDATA); + if (rxp) + *rxp++ = d; + debug("rx:%x\n", d); + } + done: + if (flags & SPI_XFER_END) + spi_cs_deactivate(slave); + + return 0; +} |