serdev: add helpers for cts and rts handling
Add serdev helper functions for handling of cts and rts
lines using the serdev's tiocm functions.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index e29a270..37395b8 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -16,6 +16,7 @@
#include <linux/types.h>
#include <linux/device.h>
#include <linux/termios.h>
+#include <linux/delay.h>
struct serdev_controller;
struct serdev_device;
@@ -254,6 +255,36 @@ static inline int serdev_device_write_room(struct serdev_device *sdev)
#endif /* CONFIG_SERIAL_DEV_BUS */
+static inline bool serdev_device_get_cts(struct serdev_device *serdev)
+{
+ int status = serdev_device_get_tiocm(serdev);
+ return !!(status & TIOCM_CTS);
+}
+
+static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
+{
+ unsigned long timeout;
+ bool signal;
+
+ timeout = jiffies + msecs_to_jiffies(timeout_ms);
+ while (time_is_after_jiffies(timeout)) {
+ signal = serdev_device_get_cts(serdev);
+ if (signal == state)
+ return 0;
+ usleep_range(1000, 2000);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
+{
+ if (enable)
+ return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
+ else
+ return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
+}
+
/*
* serdev hooks into TTY core
*/