Write the selected CS line to the CS-bits and not to the CSPOL-bits (which only
switch the polarity of a CS line)
---
c/src/lib/libbsp/arm/raspberrypi/spi/spi.c | 22 +++++-----------------
1 file changed, 5 insertions(+), 17 deletions(-)
diff --git a/c/src/lib/libbsp/arm/raspberrypi/spi/spi.c
b/c/src/lib/libbsp/arm/raspberrypi/spi/spi.c
index ae77f62..c595ca1 100644
--- a/c/src/lib/libbsp/arm/raspberrypi/spi/spi.c
+++ b/c/src/lib/libbsp/arm/raspberrypi/spi/spi.c
@@ -493,18 +493,9 @@ static rtems_status_code
rpi_libi2c_spi_stop(rtems_libi2c_bus_t * bushdl)
/* Set SPI transfer as not active. */
BCM2835_REG(BCM2835_SPI_CS) &= ~(1 << 7);
-
- /* Unselect the active SPI slave. */
- switch ( addr ) {
- case 0:
- case 1:
- BCM2835_REG(BCM2835_SPI_CS) |= (1 << chip_select_bit);
-
- break;
-
- default:
- return RTEMS_INVALID_ADDRESS;
- }
+
+ /* Deselect CS line */
+ BCM2835_REG(BCM2835_SPI_CS) &= 3;
return RTEMS_SUCCESSFUL;
}
@@ -528,10 +519,6 @@ static rtems_status_code rpi_libi2c_spi_send_addr(
) {
rpi_spi_softc_t *softc_ptr = &(((rpi_spi_desc_t *)(bushdl))->softc);
- /* Calculates the bit corresponding to the received address
- * on the SPI control register. */
- uint32_t chip_select_bit = 21 + addr;
-
/* Save which slave will be currently addressed,
* so it can be unselected later. */
softc_ptr->current_slave_addr = addr;
@@ -540,7 +527,8 @@ static rtems_status_code rpi_libi2c_spi_send_addr(
switch ( addr ) {
case 0:
case 1:
- BCM2835_REG(BCM2835_SPI_CS) &= ~(1 << chip_select_bit);
+ /* Clear the last 2 bits (CS) and set them to addr */
+ BCM2835_REG(BCM2835_SPI_CS) = (BCM2835_REG(BCM2835_SPI_CS) & (~3) ) |
addr;
break;
default:
--
2.7.4
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