The AVR CPU on the other side just can't go very fast. This reduces
the SPI clock by a factor of 16, just under 200kHz. As the companion
commands are reasonably short, this shouldn't have a huge effect on
overall SPI utilization.
Signed-off-by: Keith Packard <keithp@keithp.com>
#include "ao.h"
-#define COMPANION_SELECT() ao_spi_get_bit(COMPANION_CS)
-#define COMPANION_DESELECT() ao_spi_put_bit(COMPANION_CS)
+#define ao_spi_slow() (U0GCR = (UxGCR_CPOL_NEGATIVE | \
+ UxGCR_CPHA_FIRST_EDGE | \
+ UxGCR_ORDER_MSB | \
+ (13 << UxGCR_BAUD_E_SHIFT)))
+
+#define ao_spi_fast() (U0GCR = (UxGCR_CPOL_NEGATIVE | \
+ UxGCR_CPHA_FIRST_EDGE | \
+ UxGCR_ORDER_MSB | \
+ (17 << UxGCR_BAUD_E_SHIFT)))
+
+#define COMPANION_SELECT() do { ao_spi_get_bit(COMPANION_CS); ao_spi_slow(); } while (0)
+#define COMPANION_DESELECT() do { ao_spi_fast(); ao_spi_put_bit(COMPANION_CS); } while (0)
static __xdata struct ao_companion_command ao_companion_command;
__xdata struct ao_companion_setup ao_companion_setup;