From 8421080c367083e01e07569d82ea4fe6f63cb86c Mon Sep 17 00:00:00 2001
From: Michael Buesch <mb@bu3sch.de>
Date: Thu, 23 Oct 2008 21:43:33 +0200
Subject: pressure_control: Implement RX timeout

Signed-off-by: Michael Buesch <mb@bu3sch.de>
---
 pressure_control/firmware/main.c   |  1 +
 pressure_control/firmware/remote.c | 21 +++++++++++++++++++++
 pressure_control/firmware/remote.h |  1 +
 3 files changed, 23 insertions(+)

(limited to 'pressure_control/firmware')

diff --git a/pressure_control/firmware/main.c b/pressure_control/firmware/main.c
index ef4c81e..fc16dad 100644
--- a/pressure_control/firmware/main.c
+++ b/pressure_control/firmware/main.c
@@ -108,6 +108,7 @@ ISR(TIMER1_COMPA_vect)
 {
 	if (state.sensor_trigger_cnt > 0)
 		state.sensor_trigger_cnt--;
+	remote_1khz_work();
 }
 
 void system_timer_init(void)
diff --git a/pressure_control/firmware/remote.c b/pressure_control/firmware/remote.c
index dafca5d..29b15b4 100644
--- a/pressure_control/firmware/remote.c
+++ b/pressure_control/firmware/remote.c
@@ -36,6 +36,7 @@ static struct remote_message rx_msg;
 static uint8_t rx_msg_count;
 static bool rx_msg_valid;
 static bool rx_softirq;
+static uint16_t rx_timeout;
 
 
 static inline void usart_tx(uint8_t data)
@@ -236,6 +237,7 @@ static void usart_handle_rx_irq(void)
 		rxbuf[rx_msg_count++] = data;
 		if (rx_msg_count == sizeof(struct remote_message)) {
 			rx_msg_count = 0;
+			rx_timeout = 0;
 			mb();
 			rx_msg_valid = 1;
 			break;
@@ -254,6 +256,19 @@ ISR(USART_RXC_vect)
 	usart_handle_rx_irq();
 }
 
+/* Called with IRQs disabled. */
+static void usart_rx_timeout_check()
+{
+	if (rx_msg_count > 0)
+		rx_timeout++;
+	if (rx_timeout > 100 /* milliseconds */) {
+		/* Timeout! Reset the RX buffer. */
+		rx_msg_count = 0;
+		rx_timeout = 0;
+	}
+	mb();
+}
+
 void print_pgm(const prog_char *str)
 {
 	struct remote_message msg;
@@ -291,6 +306,12 @@ void remote_work(void)
 	sei();
 }
 
+/* Maintanance work. Called at a frequency of 1KHz with IRQs disabled. */
+void remote_1khz_work(void)
+{
+	usart_rx_timeout_check();
+}
+
 void remote_pressure_change_notification(uint16_t mbar,
 					 uint16_t hysteresis)
 {
diff --git a/pressure_control/firmware/remote.h b/pressure_control/firmware/remote.h
index ad67540..9aabfe9 100644
--- a/pressure_control/firmware/remote.h
+++ b/pressure_control/firmware/remote.h
@@ -78,6 +78,7 @@ void remote_pressure_change_notification(uint16_t mbar,
 					 uint16_t hysteresis);
 
 void remote_work(void);
+void remote_1khz_work(void);
 void remote_init(void);
 
 #endif /* REMOTE_H_ */
-- 
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