From: Keith Packard <keithp@keithp.com>
Date: Fri, 28 Apr 2017 07:02:54 +0000 (-0700)
Subject: altos/stmf0: Compute serial baud rate registers at runtime
X-Git-Tag: 1.8~160
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=ac3fc7da669f58c7abd25b0ca8cc425238b84217;hp=7d4f7880b0934c208df65cea8b0f549f32f1c7d2

altos/stmf0: Compute serial baud rate registers at runtime

This allows the system clock to vary at runtime, instead of requiring
a fixed value.

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

diff --git a/src/stmf0/ao_serial_stm.c b/src/stmf0/ao_serial_stm.c
index 30b0dbd2..06fc054a 100644
--- a/src/stmf0/ao_serial_stm.c
+++ b/src/stmf0/ao_serial_stm.c
@@ -163,24 +163,12 @@ ao_usart_drain(struct ao_stm_usart *usart)
 	ao_arch_release_interrupts();
 }
 
-static const struct {
-	uint32_t brr;
-} ao_usart_speeds[] = {
-	[AO_SERIAL_SPEED_4800] = {
-		AO_PCLK / 4800
-	},
-	[AO_SERIAL_SPEED_9600] = {
-		AO_PCLK / 9600
-	},
-	[AO_SERIAL_SPEED_19200] = {
-		AO_PCLK / 19200
-	},
-	[AO_SERIAL_SPEED_57600] = {
-		AO_PCLK / 57600
-	},
-	[AO_SERIAL_SPEED_115200] = {
-		AO_PCLK / 115200
-	},
+static const uint32_t ao_usart_speeds[] = {
+	[AO_SERIAL_SPEED_4800] = 4800,
+	[AO_SERIAL_SPEED_9600] = 9600,
+	[AO_SERIAL_SPEED_19200] = 19200,
+	[AO_SERIAL_SPEED_57600] = 57600,
+	[AO_SERIAL_SPEED_115200] = 115200,
 };
 
 static void
@@ -188,7 +176,7 @@ ao_usart_set_speed(struct ao_stm_usart *usart, uint8_t speed)
 {
 	if (speed > AO_SERIAL_SPEED_115200)
 		return;
-	usart->reg->brr = ao_usart_speeds[speed].brr;
+	usart->reg->brr = AO_PCLK / ao_usart_speeds[speed];
 }
 
 static void