[PATCH v3 3/6] serial_msm: Enable RS232 flow control

Sumit Garg sumit.garg at linaro.org
Fri Apr 5 11:07:39 CEST 2024


SE HMIBSC board debug console requires RS232 flow control, so enable
corresponding support if RS232 gpios are present.

Reviewed-by: Caleb Connolly <caleb.connolly at linaro.org>
Signed-off-by: Sumit Garg <sumit.garg at linaro.org>
---
 drivers/serial/serial_msm.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/serial/serial_msm.c b/drivers/serial/serial_msm.c
index 4de10e75191..3142ecf7362 100644
--- a/drivers/serial/serial_msm.c
+++ b/drivers/serial/serial_msm.c
@@ -53,10 +53,11 @@
 #define UARTDM_TF               0x100 /* UART Transmit FIFO register */
 #define UARTDM_RF               0x140 /* UART Receive FIFO register */
 
-#define UART_DM_CLK_RX_TX_BIT_RATE 0xCC
-#define MSM_BOOT_UART_DM_8_N_1_MODE 0x34
-#define MSM_BOOT_UART_DM_CMD_RESET_RX 0x10
-#define MSM_BOOT_UART_DM_CMD_RESET_TX 0x20
+#define UART_DM_CLK_RX_TX_BIT_RATE	0xCC
+#define MSM_BOOT_UART_DM_8_N_1_MODE	0x34
+#define MSM_BOOT_UART_DM_CMD_RESET_RX	0x10
+#define MSM_BOOT_UART_DM_CMD_RESET_TX	0x20
+#define MSM_UART_MR1_RX_RDY_CTL		BIT(7)
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -182,7 +183,9 @@ static void uart_dm_init(struct msm_serial_data *priv)
 	mdelay(5);
 
 	writel(priv->clk_bit_rate, priv->base + UARTDM_CSR);
-	writel(0x0, priv->base + UARTDM_MR1);
+
+	/* Enable RS232 flow control to support RS232 db9 connector */
+	writel(MSM_UART_MR1_RX_RDY_CTL, 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);
-- 
2.34.1



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