From 6fe729c4bdae41b4c5a5ff21312f021a48c69399 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Tue, 4 Apr 2017 07:22:33 -0700 Subject: [PATCH] serdev: Add serdev_device_write subroutine Add serdev_device_write() a blocking call allowing to transfer arbitraty amount of data (potentially exceeding amount that serdev_device_write_buf can process in a single call) To support that, also add serdev_device_write_wakeup(). Drivers wanting to use full extent of serdev_device_write functionality are 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. Because serdev_device_write() subroutine is a superset of serdev_device_write_buf() the patch re-impelements latter is terms of the former. For drivers wanting to just use serdev_device_write_buf() .write_wakeup handler is optional. Cc: cphealy@gmail.com Cc: Guenter Roeck Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Rob Herring Reviewed-by: Andy Shevchenko Signed-off-by: Andrey Smirnov Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serdev/core.c | 36 +++++++++++++++++++++++++++++++----- include/linux/serdev.h | 17 +++++++++++++++-- 2 files changed, 46 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index f4c6c90add78..6701d1011fce 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 && + (timeout = 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 5176cdc2057f..0beaff886992 100644 --- a/include/linux/serdev.h +++ b/include/linux/serdev.h @@ -39,12 +39,16 @@ 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 Lock to serialize access when writing data */ 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) @@ -186,7 +190,8 @@ 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 *); @@ -223,7 +228,8 @@ 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, unsigned long timeout) { return -ENODEV; } @@ -259,4 +265,11 @@ static inline struct device *serdev_tty_port_register(struct tty_port *port, static inline void serdev_tty_port_unregister(struct tty_port *port) {} #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */ +static inline int serdev_device_write_buf(struct serdev_device *serdev, + const unsigned char *data, + size_t count) +{ + return serdev_device_write(serdev, data, count, 0); +} + #endif /*_LINUX_SERDEV_H */ -- 2.20.1