[SRU OEM-B][PATCH 05/10] serdev: Introduce devm_serdev_device_open()

[Shrirang Bagul]

From: Andrey Smirnov <andrew.smirnov at gmail.com>

BugLink: http://bugs.launchpad.net/bugs/1769610

Add code implementing managed version of serdev_device_open() for
serdev device drivers that "open" the device during driver's lifecycle
only once (e.g. opened in .probe() and closed in .remove()).

Acked-by: Philippe Ombredanne <pombredanne at nexb.com>
Acked-by: Pavel Machek <pavel at ucw.cz>
Acked-by: Rob Herring <robh at kernel.org>
Reviewed-by: Sebastian Reichel <sebastian.reichel at collabora.co.uk>
Reviewed-by: Guenter Roeck <linux at roeck-us.net>
Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
Signed-off-by: Lee Jones <lee.jones at linaro.org>
(cherry picked from commit 2cb67d20cdea1f4da60bbe073d32bd2ba11c22ad)
Signed-off-by: Shrirang Bagul <shrirang.bagul at canonical.com>
---
 Documentation/driver-model/devres.txt |  3 +++
 drivers/tty/serdev/core.c             | 27 +++++++++++++++++++++++++++
 include/linux/serdev.h                |  1 +
 3 files changed, 31 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index c180045eb43b..7c1bb3d0c222 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -384,6 +384,9 @@ RESET
   devm_reset_control_get()
   devm_reset_controller_register()
 
+SERDEV
+  devm_serdev_device_open()
+
 SLAVE DMA ENGINE
   devm_acpi_dma_controller_register()
 
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 4504e195fdbe..5dc88f61f506 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -137,6 +137,33 @@ void serdev_device_close(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_close);
 
+static void devm_serdev_device_release(struct device *dev, void *dr)
+{
+	serdev_device_close(*(struct serdev_device **)dr);
+}
+
+int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
+{
+	struct serdev_device **dr;
+	int ret;
+
+	dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	*dr = serdev;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_serdev_device_open);
+
 void serdev_device_write_wakeup(struct serdev_device *serdev)
 {
 	complete(&serdev->write_comp);
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index d609e6dc5bad..d4bb46a26dc3 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -193,6 +193,7 @@ static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
 
 int serdev_device_open(struct serdev_device *);
 void serdev_device_close(struct serdev_device *);
+int devm_serdev_device_open(struct device *, 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);
-- 
2.14.1