drivers: serial: rpi_pico: check if baudrate was set by the API function

if peripheral clock is not configured, uart init API function returns 0,
so we need to check the return value of this function

Signed-off-by: Andrei-Edward Popa <[email protected]>

Author: Andrei-Edward Popa

drivers/serial/uart_rpi_pico.c

@@ -40,14 +40,21 @@ static void uart_rpi_poll_out(const struct device *dev, unsigned char c)
 static int uart_rpi_init(const struct device *dev)
 {
 	const struct uart_rpi_config *config = dev->config;
-	int ret;
+	uart_inst_t * const uart_inst = config->uart_dev;
+	uart_hw_t * const uart_hw = config->uart_regs;
+	struct uart_rpi_data * const data = dev->data;
+	int ret, baudrate;
 
 	ret = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
 	if (ret < 0) {
 		return ret;
 	}
 
-	uart_init(config->uart_dev, config->baudrate);
+	baudrate = uart_init(uart_inst, data->baudrate);
+	/* Check if baudrate adjustment returned by 'uart_init' function is a positive value */
+	if (baudrate <= 0) {
+		return -EINVAL;
+	}
 
 	return 0;
 }