[v2,04/12] tty: serdev: Add method to enable break flags

Commit Message

Christoph Fritz May 2, 2024, 7:55 a.m. UTC

The recently introduced callback function receive_buf_fp() brings flags
buffer support. To allow signaling of TTY_BREAK flags, this patch
introduces serdev_device_set_break_detection() and an implementation for
ttyport. This enables serdev devices to configure their underlying tty
port to signal or ignore break conditions.

Signed-off-by: Christoph Fritz <[e-mail]>
---
 drivers/tty/serdev/core.c           | 11 +++++++++++
 drivers/tty/serdev/serdev-ttyport.c | 17 +++++++++++++++++
 include/linux/serdev.h              |  2 ++
 3 files changed, 30 insertions(+)

Patch

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 613cb356b918d..23a1e76cb553b 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -339,6 +339,17 @@  unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned i
 }
 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
 
+void serdev_device_set_break_detection(struct serdev_device *serdev, bool enable)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_break_detection)
+		return;
+
+	ctrl->ops->set_break_detection(ctrl, enable);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_break_detection);
+
 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index bb47691afdb21..e928bf4175c6f 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -192,6 +192,22 @@  static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable
 	tty_set_termios(tty, &ktermios);
 }
 
+static void ttyport_set_break_detection(struct serdev_controller *ctrl, bool enable)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	ktermios.c_iflag &= ~(IGNBRK | BRKINT);
+
+	if (enable)
+		ktermios.c_iflag |= BRKINT;
+	else
+		ktermios.c_iflag |= IGNBRK;
+
+	tty_set_termios(tty, &ktermios);
+}
+
 static int ttyport_set_parity(struct serdev_controller *ctrl,
 			      enum serdev_parity parity)
 {
@@ -263,6 +279,7 @@  static const struct serdev_controller_ops ctrl_ops = {
 	.open = ttyport_open,
 	.close = ttyport_close,
 	.set_flow_control = ttyport_set_flow_control,
+	.set_break_detection = ttyport_set_break_detection,
 	.set_parity = ttyport_set_parity,
 	.set_baudrate = ttyport_set_baudrate,
 	.wait_until_sent = ttyport_wait_until_sent,
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index c6ef5a8988e07..d08aa7e16f9f8 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -94,6 +94,7 @@  struct serdev_controller_ops {
 	int (*open)(struct serdev_controller *);
 	void (*close)(struct serdev_controller *);
 	void (*set_flow_control)(struct serdev_controller *, bool);
+	void (*set_break_detection)(struct serdev_controller *, bool);
 	int (*set_parity)(struct serdev_controller *, enum serdev_parity);
 	unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
 	void (*wait_until_sent)(struct serdev_controller *, long);
@@ -215,6 +216,7 @@  void serdev_device_close(struct serdev_device *);
 int devm_serdev_device_open(struct device *, struct serdev_device *);
 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
 void serdev_device_set_flow_control(struct serdev_device *, bool);
+void serdev_device_set_break_detection(struct serdev_device *, bool);
 int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t);
 void serdev_device_wait_until_sent(struct serdev_device *, long);
 int serdev_device_get_tiocm(struct serdev_device *);