staging: gasket: core: let device driver enable/disable gasket device

Move gasket device enable/disable functions from internal calls to
external calls from the gasket device drivers.  The device driver will
call these functions at appropriate times in its processing, placing
the device driver in control of this sequence and reducing the need for
callbacks from framework back to the device drivers during the
enable/disable sequences.
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gasket/gasket_core.c

@@ -628,7 +628,7 @@ static int gasket_add_cdev(struct gasket_cdev_info *dev_info,
 }
 
 /* Disable device operations. */
-static void gasket_disable_dev(struct gasket_dev *gasket_dev)
+void gasket_disable_device(struct gasket_dev *gasket_dev)
 {
 	const struct gasket_driver_desc *driver_desc =
 		gasket_dev->internal_desc->driver_desc;
@@ -649,6 +649,7 @@ static void gasket_disable_dev(struct gasket_dev *gasket_dev)
 		}
 	}
 }
+EXPORT_SYMBOL(gasket_disable_device);
 
 /*
  * Registered descriptor lookup.
@@ -1350,13 +1351,12 @@ static const struct file_operations gasket_file_ops = {
 };
 
 /* Perform final init and marks the device as active. */
-static int gasket_enable_dev(struct gasket_internal_desc *internal_desc,
-			     struct gasket_dev *gasket_dev)
+int gasket_enable_device(struct gasket_dev *gasket_dev)
 {
 	int tbl_idx;
 	int ret;
 	const struct gasket_driver_desc *driver_desc =
-		internal_desc->driver_desc;
+		gasket_dev->internal_desc->driver_desc;
 
 	ret = gasket_interrupt_init(gasket_dev, driver_desc->name,
 				    driver_desc->interrupt_type,
@@ -1418,13 +1418,15 @@ static int gasket_enable_dev(struct gasket_internal_desc *internal_desc,
 
 	return 0;
 }
+EXPORT_SYMBOL(gasket_enable_device);
 
 /*
  * Add PCI gasket device.
  *
  * Called by Gasket device probe function.
- * Allocates device metadata, maps device memory, and calls gasket_enable_dev
- * to prepare the device for active use.
+ * Allocates device metadata and maps device memory.  The device driver must
+ * call gasket_enable_device after driver init is complete to place the device
+ * in active use.
  */
 int gasket_pci_add_device(struct pci_dev *pci_dev,
 			  struct gasket_dev **gasket_devp)
@@ -1500,13 +1502,6 @@ int gasket_pci_add_device(struct pci_dev *pci_dev,
 		goto fail5;
 	}
 
-	ret = gasket_enable_dev(internal_desc, gasket_dev);
-	if (ret) {
-		pr_err("cannot setup %s device\n", driver_desc->name);
-		gasket_disable_dev(gasket_dev);
-		goto fail5;
-	}
-
 	*gasket_devp = gasket_dev;
 	return 0;
 
@@ -1560,7 +1555,6 @@ void gasket_pci_remove_device(struct pci_dev *pci_dev)
 	dev_dbg(gasket_dev->dev, "remove %s PCI gasket device\n",
 		internal_desc->driver_desc->name);
 
-	gasket_disable_dev(gasket_dev);
 	gasket_cleanup_pci(gasket_dev);
 
 	check_and_invoke_callback(gasket_dev, driver_desc->sysfs_cleanup_cb);

drivers/staging/gasket/gasket_core.h

@@ -590,6 +590,12 @@ int gasket_pci_add_device(struct pci_dev *pci_dev,
 /* Remove a PCI gasket device. */
 void gasket_pci_remove_device(struct pci_dev *pci_dev);
 
+/* Enable a Gasket device. */
+int gasket_enable_device(struct gasket_dev *gasket_dev);
+
+/* Disable a Gasket device. */
+void gasket_disable_device(struct gasket_dev *gasket_dev);
+
 /*
  * Reset the Gasket device.
  * @gasket_dev: Gasket device struct.