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-rw-r--r--drivers/mfd/mfd-core.c61
-rw-r--r--include/linux/mfd/core.h9
2 files changed, 70 insertions, 0 deletions
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index ca789f882305..bb2264cc410b 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -184,5 +184,66 @@ void mfd_remove_devices(struct device *parent)
}
EXPORT_SYMBOL(mfd_remove_devices);
+static int add_shared_platform_device(const char *cell, const char *name)
+{
+ struct mfd_cell cell_entry;
+ struct device *dev;
+ struct platform_device *pdev;
+ int err;
+
+ /* check if we've already registered a device (don't fail if we have) */
+ if (bus_find_device_by_name(&platform_bus_type, NULL, name))
+ return 0;
+
+ /* fetch the parent cell's device (should already be registered!) */
+ dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
+ if (!dev) {
+ printk(KERN_ERR "failed to find device for cell %s\n", cell);
+ return -ENODEV;
+ }
+ pdev = to_platform_device(dev);
+ memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
+
+ WARN_ON(!cell_entry.enable);
+
+ cell_entry.name = name;
+ err = mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0);
+ if (err)
+ dev_err(dev, "MFD add devices failed: %d\n", err);
+ return err;
+}
+
+int mfd_shared_platform_driver_register(struct platform_driver *drv,
+ const char *cellname)
+{
+ int err;
+
+ err = add_shared_platform_device(cellname, drv->driver.name);
+ if (err)
+ printk(KERN_ERR "failed to add platform device %s\n",
+ drv->driver.name);
+
+ err = platform_driver_register(drv);
+ if (err)
+ printk(KERN_ERR "failed to add platform driver %s\n",
+ drv->driver.name);
+
+ return err;
+}
+EXPORT_SYMBOL(mfd_shared_platform_driver_register);
+
+void mfd_shared_platform_driver_unregister(struct platform_driver *drv)
+{
+ struct device *dev;
+
+ dev = bus_find_device_by_name(&platform_bus_type, NULL,
+ drv->driver.name);
+ if (dev)
+ platform_device_unregister(to_platform_device(dev));
+
+ platform_driver_unregister(drv);
+}
+EXPORT_SYMBOL(mfd_shared_platform_driver_unregister);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index 22a2f5ebd9db..ed9970412cc2 100644
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -87,4 +87,13 @@ extern int mfd_add_devices(struct device *parent, int id,
extern void mfd_remove_devices(struct device *parent);
+/*
+ * For MFD drivers with clients sharing access to resources, these create
+ * multiple platform devices per cell. Contention handling must still be
+ * handled via drivers (ie, with enable/disable hooks).
+ */
+extern int mfd_shared_platform_driver_register(struct platform_driver *drv,
+ const char *cellname);
+extern void mfd_shared_platform_driver_unregister(struct platform_driver *drv);
+
#endif