Re: [PATCH v8 2/5] serdev: Introduce devm_serdev_device_open()

From: Guenter Roeck
Date: Sat Oct 21 2017 - 13:09:59 EST


On 10/18/2017 10:01 AM, Andrey Smirnov wrote:
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()).

Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-serial@xxxxxxxxxxxxxxx
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: cphealy@xxxxxxxxx
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>
Cc: Lee Jones <lee.jones@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Cc: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

---
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 69f08c0f23a8..e9c6b5cfeec1 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -383,6 +383,9 @@ 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 f500f6a2ca88..b3a785665c6f 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -116,6 +116,33 @@ 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 ret;
+}
+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 e69402d4a8ae..9929063bd45d 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);