Convert serdev_device_write_buf's code to be able to transfer amount of data potentially exceeding "write room" at the moment of invocation.
To support that, also add serdev_device_write_wakeup. Drivers wanting to use full extent of serdev_device_write functionality asre expected to provide serdev_device_write_wakeup as a sole handler of .write_wakeup event or call it as a part of driver's custom .write_wakeup code. Drivers wanting to retain old serdev_device_write_buf behaviour can replace those call to calls to serdev_device_write with timeout of 0. Providing .write_wakeup handler in such case is optional. Cc: [email protected] Cc: Guenter Roeck <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Andrey Smirnov <[email protected]> --- drivers/tty/serdev/core.c | 36 +++++++++++++++++++++++++++++++----- include/linux/serdev.h | 11 +++++++++-- 2 files changed, 40 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index f4c6c90..9962d84 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -116,17 +116,41 @@ void serdev_device_close(struct serdev_device *serdev) } EXPORT_SYMBOL_GPL(serdev_device_close); -int serdev_device_write_buf(struct serdev_device *serdev, - const unsigned char *buf, size_t count) +void serdev_device_write_wakeup(struct serdev_device *serdev) +{ + complete(&serdev->write_comp); +} +EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); + +int serdev_device_write(struct serdev_device *serdev, + const unsigned char *buf, size_t count, + unsigned long timeout) { struct serdev_controller *ctrl = serdev->ctrl; + int ret; - if (!ctrl || !ctrl->ops->write_buf) + if (!ctrl || !ctrl->ops->write_buf || + (timeout && !serdev->ops->write_wakeup)) return -EINVAL; - return ctrl->ops->write_buf(ctrl, buf, count); + mutex_lock(&serdev->write_lock); + do { + reinit_completion(&serdev->write_comp); + + ret = ctrl->ops->write_buf(ctrl, buf, count); + if (ret < 0) + break; + + buf += ret; + count -= ret; + + } while (count && + wait_for_completion_timeout(&serdev->write_comp, + timeout)); + mutex_unlock(&serdev->write_lock); + return ret < 0 ? ret : (count ? -ETIMEDOUT : 0); } -EXPORT_SYMBOL_GPL(serdev_device_write_buf); +EXPORT_SYMBOL_GPL(serdev_device_write); void serdev_device_write_flush(struct serdev_device *serdev) { @@ -232,6 +256,8 @@ struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) serdev->dev.parent = &ctrl->dev; serdev->dev.bus = &serdev_bus_type; serdev->dev.type = &serdev_device_type; + init_completion(&serdev->write_comp); + mutex_init(&serdev->write_lock); return serdev; } EXPORT_SYMBOL_GPL(serdev_device_alloc); diff --git a/include/linux/serdev.h b/include/linux/serdev.h index 5176cdc..18cbbed 100644 --- a/include/linux/serdev.h +++ b/include/linux/serdev.h @@ -39,12 +39,17 @@ struct serdev_device_ops { * @nr: Device number on serdev bus. * @ctrl: serdev controller managing this device. * @ops: Device operations. + * @write_comp Completion used by serdev_device_write internally + * @write_lock Mutext used to esure exclusive access to the bus when + * writing data with serdev_device_write() */ struct serdev_device { struct device dev; int nr; struct serdev_controller *ctrl; const struct serdev_device_ops *ops; + struct completion write_comp; + struct mutex write_lock; }; static inline struct serdev_device *to_serdev_device(struct device *d) @@ -186,10 +191,12 @@ int serdev_device_open(struct serdev_device *); void serdev_device_close(struct serdev_device *); unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int); void serdev_device_set_flow_control(struct serdev_device *, bool); -int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t); +void serdev_device_write_wakeup(struct serdev_device *); +int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long); void serdev_device_write_flush(struct serdev_device *); int serdev_device_write_room(struct serdev_device *); + /* * serdev device driver functions */ @@ -223,7 +230,7 @@ static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev return 0; } static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {} -static inline int serdev_device_write_buf(struct serdev_device *sdev, const unsigned char *buf, size_t count) +static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf, size_t count) { return -ENODEV; } -- 2.9.3
