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serial: serial_stm32: Add reset support

In some cases, UART is configured by early boot stage.
To be sure of the initial state of UART and to avoid
spurious chars on console, reset the serial block before
configuring it.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Patrice Chotard 5 anos atrás
pai
commit
f828fa4d82
1 arquivos alterados com 9 adições e 0 exclusões
  1. 9 0
      drivers/serial/serial_stm32.c

+ 9 - 0
drivers/serial/serial_stm32.c

@@ -7,6 +7,7 @@
 #include <common.h>
 #include <clk.h>
 #include <dm.h>
+#include <reset.h>
 #include <serial.h>
 #include <watchdog.h>
 #include <asm/io.h>
@@ -171,6 +172,7 @@ static int stm32_serial_probe(struct udevice *dev)
 {
 	struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
 	struct clk clk;
+	struct reset_ctl reset;
 	int ret;
 
 	plat->uart_info = (struct stm32_uart_info *)dev_get_driver_data(dev);
@@ -185,6 +187,13 @@ static int stm32_serial_probe(struct udevice *dev)
 		return ret;
 	}
 
+	ret = reset_get_by_index(dev, 0, &reset);
+	if (!ret) {
+		reset_assert(&reset);
+		udelay(2);
+		reset_deassert(&reset);
+	}
+
 	plat->clock_rate = clk_get_rate(&clk);
 	if (plat->clock_rate < 0) {
 		clk_disable(&clk);