From 8ae36e163028e8611b0c3d662129d54a59eebbed Mon Sep 17 00:00:00 2001
From: bsekisser <squirmyworms@embarqmail.com>
Date: Mon, 12 Oct 2020 15:07:42 -0400
Subject: [PATCH] Remove kludge "avr_uart_regbit_clear" from uart

	modified:   sim/avr_uart.c

Change use of kludge function avr_uart_regbit_clear to avr_regbit_clear.

	modified:   sim/sim_regbit.h

Add check that avr_regbit_clear was passed a valid existing register.
---
 simavr/sim/avr_uart.c   | 19 ++++---------------
 simavr/sim/sim_regbit.h |  2 ++
 2 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/simavr/sim/avr_uart.c b/simavr/sim/avr_uart.c
index 4e3db86..b0b5770 100644
--- a/simavr/sim/avr_uart.c
+++ b/simavr/sim/avr_uart.c
@@ -61,17 +61,6 @@ avr_uart_clear_interrupt(
 		avr_regbit_clear(avr, vector->raised);
 }
 
-static inline void
-avr_uart_regbit_clear(
-		avr_t * avr,
-		avr_regbit_t rb)
-{
-	uint16_t a = rb.reg;
-	if (!a)
-		return;
-	avr_regbit_clear(avr, rb);
-}
-
 static avr_cycle_count_t
 avr_uart_txc_raise(
 		struct avr_t * avr,
@@ -225,7 +214,7 @@ avr_uart_read_check:
 		avr_raise_irq(p->io.irq + UART_IRQ_OUT_XON, 1);
 	}
 	if (!uart_fifo_isfull(&p->input)) {
-		avr_uart_regbit_clear(avr, p->dor);
+		avr_regbit_clear(avr, p->dor);
 	}
 
 	return v;
@@ -432,7 +421,7 @@ avr_uart_irq_input(
 			) {
 		avr_cycle_timer_register(avr, p->cycles_per_byte, avr_uart_rxc_raise, p); // start the rx pump
 		p->rx_cnt = 0;
-		avr_uart_regbit_clear(avr, p->dor);
+		avr_regbit_clear(avr, p->dor);
 	} else if (uart_fifo_isfull(&p->input)) {
 		avr_regbit_setto(avr, p->dor, 1);
 	}
@@ -458,7 +447,7 @@ avr_uart_reset(
 	avr_t * avr = p->io.avr;
 	if (p->udrc.vector) {
 		avr_regbit_set(avr, p->udrc.raised);
-		avr_uart_regbit_clear(avr, p->dor);
+		avr_regbit_clear(avr, p->dor);
 	}
 	avr_uart_clear_interrupt(avr, &p->txc);
 	avr_uart_clear_interrupt(avr, &p->rxc);
@@ -469,7 +458,7 @@ avr_uart_reset(
 	p->tx_cnt =  0;
 
 	avr_regbit_set(avr, p->ucsz);
-	avr_uart_regbit_clear(avr, p->ucsz2);
+	avr_regbit_clear(avr, p->ucsz2);
 
 	// DEBUG allow printf without fiddling with enabling the uart
 	avr_regbit_set(avr, p->txen);
diff --git a/simavr/sim/sim_regbit.h b/simavr/sim/sim_regbit.h
index 2565195..4b511e9 100644
--- a/simavr/sim/sim_regbit.h
+++ b/simavr/sim/sim_regbit.h
@@ -119,6 +119,8 @@ static inline uint8_t avr_regbit_get_raw(avr_t * avr, avr_regbit_t rb)
 static inline uint8_t avr_regbit_clear(avr_t * avr, avr_regbit_t rb)
 {
 	uint16_t a = rb.reg;
+	if (!a)
+		return 0;
 	uint8_t m = rb.mask << rb.bit;
 	avr_core_watch_write(avr, a, avr->data[a] & ~m);
 	return avr->data[a];
-- 
2.39.5