[U-Boot] [PATCH 38/48] serial: stm32: add Framing error support

[Patrick Delaunay]

Add management of Bit 1 of USART_ISR = FE: Framing error
This bit is set by hardware when a de-synchronization, excessive noise
or a break character is detected. It is cleared by software, writing 1
to the FECF bit in the USART_ICR register (for stm32 after f4).

Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
---

 drivers/serial/serial_stm32.c | 5 +++--
 drivers/serial/serial_stm32.h | 2 ++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/serial/serial_stm32.c b/drivers/serial/serial_stm32.c
index 3ab536a..00a8e72 100644
--- a/drivers/serial/serial_stm32.c
+++ b/drivers/serial/serial_stm32.c
@@ -106,10 +106,11 @@ static int stm32_serial_getc(struct udevice *dev)
 	if ((isr & USART_ISR_RXNE) == 0)
 		return -EAGAIN;
 
-	if (isr & (USART_ISR_PE | USART_ISR_ORE)) {
+	if (isr & (USART_ISR_PE | USART_ISR_ORE | USART_ISR_FE)) {
 		if (!stm32f4)
 			setbits_le32(base + ICR_OFFSET,
-				     USART_ICR_PCECF | USART_ICR_ORECF);
+				     USART_ICR_PCECF | USART_ICR_ORECF |
+				     USART_ICR_FECF);
 		else
 			readl(base + RDR_OFFSET(stm32f4));
 		return -EIO;
diff --git a/drivers/serial/serial_stm32.h b/drivers/serial/serial_stm32.h
index 5549f8c..7b0c531 100644
--- a/drivers/serial/serial_stm32.h
+++ b/drivers/serial/serial_stm32.h
@@ -67,6 +67,7 @@ struct stm32x7_serial_platdata {
 #define USART_ISR_TXE			BIT(7)
 #define USART_ISR_RXNE			BIT(5)
 #define USART_ISR_ORE			BIT(3)
+#define USART_ISR_FE			BIT(1)
 #define USART_ISR_PE			BIT(0)
 
 #define USART_BRR_F_MASK		GENMASK(7, 0)
@@ -74,6 +75,7 @@ struct stm32x7_serial_platdata {
 #define USART_BRR_M_MASK		GENMASK(15, 4)
 
 #define USART_ICR_ORECF			BIT(3)
+#define USART_ICR_FECF			BIT(1)
 #define USART_ICR_PCECF			BIT(0)
 
 #endif
-- 
2.7.4