[PATCHv3 04/10] serdev: add helpers for cts and rts handling
From: Sebastian Reichel <sre@kernel.org>
Date: 2017-03-28 16:00:59
Also in:
linux-bluetooth, linux-serial, lkml
Subsystem:
serial device bus, the rest · Maintainers:
Rob Herring, Linus Torvalds
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> --- Changes since PATCHv2: * use time_is_after_jiffies(xyz) instead of !time_after(jiffies, xyz) * drop OUT2 handling in rts function --- include/linux/serdev.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index e29a270f603c..37395b8eb8f1 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 */
--
2.11.0