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Posted to commits@nuttx.apache.org by ag...@apache.org on 2020/06/15 22:20:03 UTC
[incubator-nuttx] 01/02: stm32l4 serial fix: clock divider for baud
rate was not correctly set
This is an automated email from the ASF dual-hosted git repository.
aguettouche pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
commit 3f1e89e30f3890664d500afcaef368b06149f5d0
Author: Matias Nitsche <mn...@dc.uba.ar>
AuthorDate: Sun Apr 19 17:48:16 2020 -0300
stm32l4 serial fix: clock divider for baud rate was not correctly set
---
arch/arm/src/stm32l4/stm32l4_serial.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm/src/stm32l4/stm32l4_serial.c b/arch/arm/src/stm32l4/stm32l4_serial.c
index b083e3f..2fa430f 100644
--- a/arch/arm/src/stm32l4/stm32l4_serial.c
+++ b/arch/arm/src/stm32l4/stm32l4_serial.c
@@ -963,11 +963,14 @@ static void stm32l4serial_setformat(FAR struct uart_dev_s *dev)
/* Use oversamply by 8 only if the divisor is small. But what is small? */
cr1 = stm32l4serial_getreg(priv, STM32L4_USART_CR1_OFFSET);
+ brr = stm32l4serial_getreg(priv, STM32L4_USART_BRR_OFFSET);
+ brr &= ~(USART_BRR_MANT_MASK | USART_BRR_FRAC_MASK);
+
if (usartdiv8 > 100)
{
/* Use usartdiv16 */
- brr = (usartdiv8 + 1) >> 1;
+ brr |= (usartdiv8 + 1) >> 1;
/* Clear oversampling by 8 to enable oversampling by 16 */
@@ -979,7 +982,7 @@ static void stm32l4serial_setformat(FAR struct uart_dev_s *dev)
/* Perform mysterious operations on bits 0-3 */
- brr = ((usartdiv8 & 0xfff0) | ((usartdiv8 & 0x000f) >> 1));
+ brr |= ((usartdiv8 & 0xfff0) | ((usartdiv8 & 0x000f) >> 1));
/* Set oversampling by 8 */