diff options
Diffstat (limited to 'drivers/spi/mpc8xxx_spi.c')
| -rw-r--r-- | drivers/spi/mpc8xxx_spi.c | 57 |
1 files changed, 31 insertions, 26 deletions
diff --git a/drivers/spi/mpc8xxx_spi.c b/drivers/spi/mpc8xxx_spi.c index 18e68d3..a3d1c95 100644 --- a/drivers/spi/mpc8xxx_spi.c +++ b/drivers/spi/mpc8xxx_spi.c @@ -27,16 +27,13 @@ #ifdef CONFIG_HARD_SPI -#define SPI_EV_NE 0x80000000 >> 22 /* Receiver Not Empty */ -#define SPI_EV_NF 0x80000000 >> 23 /* Transmitter Not Full */ +#define SPI_EV_NE (0x80000000 >> 22) /* Receiver Not Empty */ +#define SPI_EV_NF (0x80000000 >> 23) /* Transmitter Not Full */ -#define SPI_MODE_LOOP 0x80000000 >> 1 /* Loopback mode */ -#define SPI_MODE_REV 0x80000000 >> 5 /* Reverse mode - MSB first */ -#define SPI_MODE_MS 0x80000000 >> 6 /* Always master */ -#define SPI_MODE_EN 0x80000000 >> 7 /* Enable interface */ - -#define SPI_PRESCALER(reg, div) (reg)=((reg) & 0xfff0ffff) | ((div)<<16) -#define SPI_CHARLENGTH(reg, div) (reg)=((reg) & 0xff0fffff) | ((div)<<20) +#define SPI_MODE_LOOP (0x80000000 >> 1) /* Loopback mode */ +#define SPI_MODE_REV (0x80000000 >> 5) /* Reverse mode - MSB first */ +#define SPI_MODE_MS (0x80000000 >> 6) /* Always master */ +#define SPI_MODE_EN (0x80000000 >> 7) /* Enable interface */ #define SPI_TIMEOUT 1000 @@ -44,18 +41,19 @@ void spi_init(void) { volatile spi8xxx_t *spi = &((immap_t *) (CFG_IMMR))->spi; - /* ------------------------------------------------ + /* * SPI pins on the MPC83xx are not muxed, so all we do is initialize * some registers - * ------------------------------------------------ */ + */ spi->mode = SPI_MODE_REV | SPI_MODE_MS | SPI_MODE_EN; - SPI_PRESCALER(spi->mode, 1); /* Use SYSCLK / 8 (16.67MHz typ.) */ + spi->mode = (spi->mode & 0xfff0ffff) | (1 << 16); /* Use SYSCLK / 8 + (16.67MHz typ.) */ spi->event = 0xffffffff; /* Clear all SPI events */ spi->mask = 0x00000000; /* Mask all SPI interrupts */ spi->com = 0; /* LST bit doesn't do anything, so disregard */ } -int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar * dout, uchar * din) +int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din) { volatile spi8xxx_t *spi = &((immap_t *) (CFG_IMMR))->spi; unsigned int tmpdout, tmpdin, event; @@ -81,16 +79,21 @@ int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar * dout, uchar * din) /* The LEN field of the SPMODE register is set as follows: * - * Bit length setting - * l <= 4 3 - * 4 < l <= 16 l - 1 - * l > 16 0 + * Bit length setting + * len <= 4 3 + * 4 < len <= 16 len - 1 + * len > 16 0 */ - if (bitlen <= 16) - SPI_CHARLENGTH(spi->mode, bitlen <= 4 ? 3 : bitlen - 1); - else { - SPI_CHARLENGTH(spi->mode, 0); + if (bitlen <= 16) { + if (bitlen <= 4) + spi->mode = (spi->mode & 0xff0fffff) | + (3 << 20); + else + spi->mode = (spi->mode & 0xff0fffff) | + ((bitlen - 1) << 20); + } else { + spi->mode = (spi->mode & 0xff0fffff); /* Set up the next iteration if sending > 32 bits */ bitlen -= 32; dout += 4; @@ -99,11 +102,11 @@ int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar * dout, uchar * din) spi->tx = tmpdout; /* Write the data out */ debug("*** spi_xfer: ... %08x written\n", tmpdout); - /* -------------------------------- + /* * Wait for SPI transmit to get out * or time out (1 second = 1000 ms) * The NE event must be read and cleared first - * -------------------------------- */ + */ for (tm = 0, isRead = 0; tm < SPI_TIMEOUT; ++tm) { event = spi->event; if (event & SPI_EV_NE) { @@ -117,10 +120,12 @@ int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar * dout, uchar * din) din += 4; } } - /* Only bail when we've had both NE and NF events. + /* + * Only bail when we've had both NE and NF events. * This will cause timeouts on RO devices, so maybe * in the future put an arbitrary delay after writing - * the device. Arbitrary delays suck, though... */ + * the device. Arbitrary delays suck, though... + */ if (isRead && (event & SPI_EV_NF)) break; } @@ -132,7 +137,7 @@ int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar * dout, uchar * din) if (chipsel != NULL) (*chipsel) (0); /* deselect the target chip */ + return 0; } - #endif /* CONFIG_HARD_SPI */ |