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path: root/drivers/spi/mpc8xxx_spi.c
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Diffstat (limited to 'drivers/spi/mpc8xxx_spi.c')
-rw-r--r--drivers/spi/mpc8xxx_spi.c57
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 */