[PATCH 01/11] ALSA: vsnd: Implement driver's probe/remove

From: Oleksandr Andrushchenko
Date: Mon Aug 07 2017 - 03:46:41 EST


From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Add essential driver private info structure, initialize
locks and implement probe/remove of the Xen frontend
driver.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
sound/drivers/xen-front.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/sound/drivers/xen-front.c b/sound/drivers/xen-front.c
index 61779c36cae3..8c5de7b0e7b5 100644
--- a/sound/drivers/xen-front.c
+++ b/sound/drivers/xen-front.c
@@ -26,6 +26,16 @@

#include <xen/interface/io/sndif.h>

+struct xdrv_info {
+ struct xenbus_device *xb_dev;
+ spinlock_t io_lock;
+ struct mutex mutex;
+};
+
+static void xdrv_remove_internal(struct xdrv_info *drv_info)
+{
+}
+
static void xdrv_be_on_changed(struct xenbus_device *xb_dev,
enum xenbus_state backend_state)
{
@@ -34,11 +44,28 @@ static void xdrv_be_on_changed(struct xenbus_device *xb_dev,
static int xdrv_probe(struct xenbus_device *xb_dev,
const struct xenbus_device_id *id)
{
+ struct xdrv_info *drv_info;
+
+ drv_info = devm_kzalloc(&xb_dev->dev, sizeof(*drv_info), GFP_KERNEL);
+ if (!drv_info) {
+ xenbus_dev_fatal(xb_dev, -ENOMEM, "allocating device memory");
+ return -ENOMEM;
+ }
+
+ drv_info->xb_dev = xb_dev;
+ spin_lock_init(&drv_info->io_lock);
+ mutex_init(&drv_info->mutex);
+ dev_set_drvdata(&xb_dev->dev, drv_info);
return 0;
}

static int xdrv_remove(struct xenbus_device *dev)
{
+ struct xdrv_info *drv_info = dev_get_drvdata(&dev->dev);
+
+ mutex_lock(&drv_info->mutex);
+ xdrv_remove_internal(drv_info);
+ mutex_unlock(&drv_info->mutex);
return 0;
}

--
2.7.4