Add serdev helper functions for handling of cts and rts
lines using the serdev's tiocm functions.
Signed-off-by: Sebastian Reichel <s...@kernel.org>
---
include/linux/serdev.h | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 3ad1d695f947..8cdce2ea0d51 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -16,6 +16,7 @@
#include <linux/types.h>
#include <linux/device.h>
#include <asm-generic/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_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_OUT2 | TIOCM_RTS,
0);
+ else
+ return serdev_device_set_tiocm(serdev, 0, TIOCM_OUT2 |
TIOCM_RTS);
+}
+
/*
* serdev hooks into TTY core
*/
--
2.11.0
