altos: Make cc1120 driver wait for TX finished

Otherwise, we may come in and try to use the radio again too quickly,
causing it to go into a TX fifo error state.

This change watches the MARC status until the transmitter is
explicitly marked as finished.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/drivers/ao_cc1120.c b/src/drivers/ao_cc1120.c
index 5add45e437ac84daf7a81c49a94d3c4b3562ea43..bad0c856288112dcd7653f81795b250f5844cf8c 100644 (file)
--- a/src/drivers/ao_cc1120.c
+++ b/src/drivers/ao_cc1120.c
@@ -30,6 +30,7 @@ static uint8_t ao_radio_wake;         /* radio ready. Also used as sleep address */
 static uint8_t ao_radio_abort;         /* radio operation should abort */
 static uint8_t ao_radio_mcu_wake;      /* MARC status change */
 static uint8_t ao_radio_marc_status;   /* Last read MARC status value */
+static uint8_t ao_radio_tx_finished;   /* MARC status indicates TX finished */
 
 #define CC1120_DEBUG   AO_FEC_DEBUG
 #define CC1120_TRACE   0
@@ -242,6 +243,8 @@ ao_radio_check_marc_status(void)
        /* Anyt other than 'tx/rx finished' means an error occurred */
        if (ao_radio_marc_status & ~(CC1120_MARC_STATUS1_TX_FINISHED|CC1120_MARC_STATUS1_RX_FINISHED))
                ao_radio_abort = 1;
+       if (ao_radio_marc_status & (CC1120_MARC_STATUS1_TX_FINISHED))
+               ao_radio_tx_finished = 1;
 }
 
 static void
@@ -258,6 +261,7 @@ ao_radio_start_tx(void)
        ao_exti_set_callback(AO_CC1120_INT_PORT, AO_CC1120_INT_PIN, ao_radio_isr);
        ao_exti_enable(AO_CC1120_INT_PORT, AO_CC1120_INT_PIN);
        ao_exti_enable(AO_CC1120_MCU_WAKEUP_PORT, AO_CC1120_MCU_WAKEUP_PIN);
+       ao_radio_tx_finished = 0;
        ao_radio_strobe(CC1120_STX);
 }
 
@@ -746,6 +750,8 @@ ao_radio_send(const void *d, uint8_t size)
                        break;
                }
        }
+       while (started && !ao_radio_abort && !ao_radio_tx_finished)
+               ao_radio_wait_isr(0);
        ao_radio_put();
 }