xshm: Add XSHM device bus.

Add a simple xshm device bus, providing device and driver registration
and a simple iterator. Device mode (packet or stream) is used
for matching device and driver.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>

diff --git a/drivers/xshm/xshm_bus.c b/drivers/xshm/xshm_bus.c
new file mode 100644 (file)
index 0000000..d6410a6
--- /dev/null
+++ b/drivers/xshm/xshm_bus.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2011
+ * Author: Sjur Brændeland / sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/xshm/xshm_dev.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sjur Brændland <sjur.brandeland@stericsson.com>");
+
+static int xshm_dev_match(struct device *_dv, struct device_driver *_dr)
+{
+       struct xshm_dev *dev = container_of(_dv, struct xshm_dev, dev);
+       struct xshm_driver *drv = container_of(_dr, struct xshm_driver, driver);
+
+       return drv->mode ==  (drv->mode & dev->cfg.mode);
+}
+
+static int xshm_dev_probe(struct device *_d)
+{
+       struct xshm_dev *dev = container_of(_d, struct xshm_dev, dev);
+       struct xshm_driver *drv = container_of(dev->dev.driver,
+                                                struct xshm_driver, driver);
+       return drv->probe(dev);
+}
+
+static int xshm_dev_remove(struct device *_d)
+{
+       struct xshm_dev *dev = container_of(_d, struct xshm_dev, dev);
+       struct xshm_driver *drv = container_of(dev->dev.driver,
+                                                struct xshm_driver, driver);
+       drv->remove(dev);
+       return 0;
+}
+
+static struct bus_type xshm_bus = {
+       .name  = "xshm",
+       .match = xshm_dev_match,
+       .probe = xshm_dev_probe,
+       .remove = xshm_dev_remove,
+};
+
+struct xshm_iter_data {
+       void *data;
+       void (*fn)(struct xshm_dev *, void *);
+};
+
+int xshm_iter(struct device *_dev, void *data)
+{
+       struct xshm_dev *dev = container_of(_dev, struct xshm_dev, dev);
+       struct xshm_iter_data *iter_data = data;
+
+       iter_data->fn(dev, iter_data->data);
+       return 0;
+}
+
+void xshm_foreach_dev(void fn(struct xshm_dev *, void *), void *data)
+{
+       struct xshm_iter_data iter = {
+               .data = data,
+               .fn = fn
+       };
+
+       bus_for_each_dev(&xshm_bus, NULL, &iter, xshm_iter);
+}
+EXPORT_SYMBOL_GPL(xshm_foreach_dev);
+
+int xshm_register_driver(struct xshm_driver *driver)
+{
+       driver->driver.bus = &xshm_bus;
+       return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(xshm_register_driver);
+
+void xshm_unregister_driver(struct xshm_driver *driver)
+{
+       driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(xshm_unregister_driver);
+
+int xshm_register_device(struct xshm_dev *dev)
+{
+       int err;
+
+       dev->dev.bus = &xshm_bus;
+       err = device_register(&dev->dev);
+       return err;
+}
+EXPORT_SYMBOL_GPL(xshm_register_device);
+
+void xshm_unregister_device(struct xshm_dev *dev)
+{
+       device_unregister(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(xshm_unregister_device);
+
+static int xshm_bus_init(void)
+{
+       if (bus_register(&xshm_bus) != 0)
+               panic("xshm bus registration failed");
+       return 0;
+}
+
+static void __exit xshm_bus_exit(void)
+{
+       bus_unregister(&xshm_bus);
+}
+
+core_initcall(xshm_bus_init);
+module_exit(xshm_bus_exit);