[PATCH V2 2/2] tty: serial: imx: Add missing wakeup event reporting

From: Sherry Sun

Date: Tue Sep 23 2025 - 23:17:24 EST


Current imx uart wakeup event would not report itself as wakeup source
through sysfs. Add pm_wakeup_event() to support it.

Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
drivers/tty/serial/imx.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 87d841c0b22f..b83f5c9c722c 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -30,7 +30,7 @@
#include <linux/iopoll.h>
#include <linux/dma-mapping.h>

-#include <asm/irq.h>
+#include <linux/irq.h>
#include <linux/dma/imx-dma.h>

#include "serial_mctrl_gpio.h"
@@ -2700,8 +2700,8 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
struct tty_port *port = &sport->port.state->port;
struct tty_struct *tty;
struct device *tty_dev;
- bool may_wake = false;
- u32 ucr3;
+ bool may_wake = false, wake_active = false;
+ u32 ucr3, usr1;

tty = tty_port_tty_get(port);
if (tty) {
@@ -2716,12 +2716,14 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)

uart_port_lock_irq(&sport->port);

+ usr1 = imx_uart_readl(sport, USR1);
ucr3 = imx_uart_readl(sport, UCR3);
if (on) {
imx_uart_writel(sport, USR1_AWAKE, USR1);
ucr3 |= UCR3_AWAKEN;
} else {
ucr3 &= ~UCR3_AWAKEN;
+ wake_active = usr1 & USR1_AWAKE;
}
imx_uart_writel(sport, ucr3, UCR3);

@@ -2732,10 +2734,14 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
ucr1 |= UCR1_RTSDEN;
} else {
ucr1 &= ~UCR1_RTSDEN;
+ wake_active |= usr1 & USR1_RTSD;
}
imx_uart_writel(sport, ucr1, UCR1);
}

+ if (wake_active && irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq)))
+ pm_wakeup_event(tty_port_tty_get(port)->dev, 0);
+
uart_port_unlock_irq(&sport->port);
}

--
2.34.1