Add minimal bus locking API which is useful for serial devices that
implement request-reply protocol
Cc: cphealy@xxxxxxxxx
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: linux-serial@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
drivers/tty/serdev/core.c | 1 +
include/linux/serdev.h | 11 +++++++++++
2 files changed, 12 insertions(+)
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 759e834..20ca231 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -269,6 +269,7 @@ struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
serdev->dev.type = &serdev_device_type;
init_completion(&serdev->write_wakeup);
mutex_init(&serdev->write_lock);
+ mutex_init(&serdev->bus_lock);
return serdev;
}
EXPORT_SYMBOL_GPL(serdev_device_alloc);
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 8f7aa35..6b73a79 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -48,6 +48,7 @@ struct serdev_device {
const struct serdev_device_ops *ops;
struct completion write_wakeup;
struct mutex write_lock;
+ struct mutex bus_lock;
};
static inline struct serdev_device *to_serdev_device(struct device *d)
@@ -55,6 +56,16 @@ static inline struct serdev_device *to_serdev_device(struct device *d)
return container_of(d, struct serdev_device, dev);
}
+static inline void serdev_device_bus_lock(struct serdev_device *serdev)
+{
+ mutex_lock(&serdev->bus_lock);
+}
+
+static inline void serdev_device_bus_unlock(struct serdev_device *serdev)
+{
+ mutex_unlock(&serdev->bus_lock);
+}
+
/**
* struct serdev_device_driver - serdev slave device driver
* @driver: serdev device drivers should initialize name field of this
--
2.9.3
--
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