[U-Boot] [PATCH v1 4/6] serial: stm32x7: add fifo support for STM32H7

[patrice.chotard at st.com]

From: Patrice Chotard <patrice.chotard at st.com>

Add fifo mode support for rx and tx.
As only STM32H7 supports this feature, add has_fifo flag
to uart configuration to use fifo only when possible.

Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
---
 drivers/serial/serial_stm32x7.c |  6 ++++--
 drivers/serial/serial_stm32x7.h | 12 +++++++++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/serial/serial_stm32x7.c b/drivers/serial/serial_stm32x7.c
index 81a2308..19697e3 100644
--- a/drivers/serial/serial_stm32x7.c
+++ b/drivers/serial/serial_stm32x7.c
@@ -117,6 +117,8 @@ static int stm32_serial_probe(struct udevice *dev)
 		     BIT(uart_enable_bit));
 	if (plat->uart_info->has_overrun_disable)
 		setbits_le32(base + CR3_OFFSET(stm32f4), USART_CR3_OVRDIS);
+	if (plat->uart_info->has_fifo)
+		setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_FIFOEN);
 	setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE |
 		     BIT(uart_enable_bit));
 
@@ -125,8 +127,8 @@ static int stm32_serial_probe(struct udevice *dev)
 
 #if CONFIG_IS_ENABLED(OF_CONTROL)
 static const struct udevice_id stm32_serial_id[] = {
-	{ .compatible = "st,stm32f7-uart", .data = (ulong)&stm32x7_info},
-	{ .compatible = "st,stm32h7-uart", .data = (ulong)&stm32x7_info},
+	{ .compatible = "st,stm32f7-uart", .data = (ulong)&stm32f7_info},
+	{ .compatible = "st,stm32h7-uart", .data = (ulong)&stm32h7_info},
 	{}
 };
 
diff --git a/drivers/serial/serial_stm32x7.h b/drivers/serial/serial_stm32x7.h
index 4c6b7d4..ed8a3ee 100644
--- a/drivers/serial/serial_stm32x7.h
+++ b/drivers/serial/serial_stm32x7.h
@@ -24,12 +24,21 @@ struct stm32_uart_info {
 	u8 uart_enable_bit;	/* UART_CR1_UE */
 	bool stm32f4;		/* true for STM32F4, false otherwise */
 	bool has_overrun_disable;
+	bool has_fifo;
 };
 
-struct stm32_uart_info stm32x7_info = {
+struct stm32_uart_info stm32f7_info = {
 	.uart_enable_bit = 0,
 	.stm32f4 = false,
 	.has_overrun_disable = true,
+	.has_fifo = false,
+};
+
+struct stm32_uart_info stm32h7_info = {
+	.uart_enable_bit = 0,
+	.stm32f4 = false,
+	.has_overrun_disable = true,
+	.has_fifo = true,
 };
 
 /* Information about a serial port */
@@ -39,6 +48,7 @@ struct stm32x7_serial_platdata {
 	unsigned long int clock_rate;
 };
 
+#define USART_CR1_FIFOEN		BIT(29)
 #define USART_CR1_OVER8			BIT(15)
 #define USART_CR1_TE			BIT(3)
 #define USART_CR1_RE			BIT(2)
-- 
1.9.1