serial: stm32: add Framing error support

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@st.com>

diff --git a/drivers/serial/serial_stm32.c b/drivers/serial/serial_stm32.c
index 3ab536a..00a8e72 100644 (file)
--- 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 (file)
--- 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