Add serdev helper functions for handling of cts and rts lines using the serdev's tiocm functions. Acked-by: Rob Herring <robh@xxxxxxxxxx> Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html