diff mbox series

[3/7] serial_msm: Enable RS232 flow control

Message ID 20231218072428.1802969-4-sumit.garg@linaro.org
State New
Headers show
Series Add SE HMBSC board support | expand

Commit Message

Sumit Garg Dec. 18, 2023, 7:24 a.m. UTC 
SE HMIBSC board debug console requires RS232 flow control, so enable
corresponding support if RS232 gpios are present.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
 drivers/serial/serial_msm.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/serial/serial_msm.c b/drivers/serial/serial_msm.c
index 43e58595dc2..a38bf229f06 100644
--- a/drivers/serial/serial_msm.c
+++ b/drivers/serial/serial_msm.c
@@ -35,6 +35,8 @@ 
 #define UARTDM_MR2				 0x04
 #define UARTDM_CSR				 0xA0
 
+#define MSM_UART_MR1_RX_RDY_CTL		BIT(7)
+
 #define UARTDM_SR                0xA4 /* Status register */
 #define UARTDM_SR_RX_READY       (1 << 0) /* Word is the receiver FIFO */
 #define UARTDM_SR_TX_EMPTY       (1 << 3) /* Transmitter underrun */
@@ -193,13 +195,18 @@  static int msm_uart_clk_init(struct udevice *dev)
 	return 0;
 }
 
-static void uart_dm_init(struct msm_serial_data *priv)
+static void uart_dm_init(struct msm_serial_data *priv, bool is_rs232)
 {
 	/* Delay initialization for a bit to let pins stabilize if necessary */
 	mdelay(5);
 
 	writel(priv->clk_bit_rate, priv->base + UARTDM_CSR);
-	writel(0x0, priv->base + UARTDM_MR1);
+
+	if (is_rs232)
+		writel(MSM_UART_MR1_RX_RDY_CTL, priv->base + UARTDM_MR1);
+	else
+		writel(0x0, priv->base + UARTDM_MR1);
+
 	writel(MSM_BOOT_UART_DM_8_N_1_MODE, priv->base + UARTDM_MR2);
 	writel(MSM_BOOT_UART_DM_CMD_RESET_RX, priv->base + UARTDM_CR);
 	writel(MSM_BOOT_UART_DM_CMD_RESET_TX, priv->base + UARTDM_CR);
@@ -212,6 +219,7 @@  static int msm_serial_probe(struct udevice *dev)
 	int ret;
 	struct msm_serial_data *priv = dev_get_priv(dev);
 	struct gpio_desc rs232_0, rs232_1;
+	bool is_rs232 = false;
 
 	/* No need to reinitialize the UART after relocation */
 	if (gd->flags & GD_FLG_RELOC)
@@ -221,13 +229,15 @@  static int msm_serial_probe(struct udevice *dev)
 	if (ret)
 		return ret;
 
-	if (!gpio_request_by_name(dev, "gpios", 0, &rs232_0, GPIOD_IS_OUT))
+	if (!gpio_request_by_name(dev, "gpios", 0, &rs232_0, GPIOD_IS_OUT)) {
 		dm_gpio_set_value(&rs232_0, 1);
+		is_rs232 = true;
+	}
 	if (!gpio_request_by_name(dev, "gpios", 1, &rs232_1, GPIOD_IS_OUT))
 		dm_gpio_set_value(&rs232_1, 0);
 
 	pinctrl_select_state(dev, "uart");
-	uart_dm_init(priv);
+	uart_dm_init(priv, is_rs232);
 
 	return 0;
 }