modem_shm: Add SHM device bus.

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

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>

diff --git a/drivers/modem_shm/shm_bus.c b/drivers/modem_shm/shm_bus.c
new file mode 100644 (file)
index 0000000..6ca238d
--- /dev/null
+++ b/drivers/modem_shm/shm_bus.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2012
+ * 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/modem_shm/shm_dev.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sjur Brændland <sjur.brandeland@stericsson.com>");
+
+static int shm_dev_match(struct device *_dv, struct device_driver *_dr)
+{
+       struct shm_dev *dev = container_of(_dv, struct shm_dev, dev);
+       struct shm_driver *drv = container_of(_dr, struct shm_driver, driver);
+
+       return drv->mode ==  (drv->mode & dev->cfg.mode);
+}
+
+static int shm_dev_probe(struct device *_d)
+{
+       struct shm_dev *dev = container_of(_d, struct shm_dev, dev);
+       struct shm_driver *drv = container_of(dev->dev.driver,
+                                                struct shm_driver, driver);
+       return drv->probe(dev);
+}
+
+static int shm_dev_remove(struct device *_d)
+{
+       struct shm_dev *dev = container_of(_d, struct shm_dev, dev);
+       struct shm_driver *drv = container_of(dev->dev.driver,
+                                                struct shm_driver, driver);
+       drv->remove(dev);
+       return 0;
+}
+
+static struct bus_type shm_bus = {
+       .name  = "modem_shm",
+       .match = shm_dev_match,
+       .probe = shm_dev_probe,
+       .remove = shm_dev_remove,
+};
+
+struct shm_iter_data {
+       void *data;
+       void (*fn)(struct shm_dev *, void *);
+};
+
+int shm_iter(struct device *_dev, void *data)
+{
+       struct shm_dev *dev = container_of(_dev, struct shm_dev, dev);
+       struct shm_iter_data *iter_data = data;
+
+       iter_data->fn(dev, iter_data->data);
+       return 0;
+}
+
+void modem_shm_foreach_dev(void fn(struct shm_dev *, void *), void *data)
+{
+       struct shm_iter_data iter = {
+               .data = data,
+               .fn = fn
+       };
+
+       bus_for_each_dev(&shm_bus, NULL, &iter, shm_iter);
+}
+EXPORT_SYMBOL_GPL(modem_shm_foreach_dev);
+
+int modem_shm_register_driver(struct shm_driver *driver)
+{
+       driver->driver.bus = &shm_bus;
+       return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(modem_shm_register_driver);
+
+void modem_shm_unregister_driver(struct shm_driver *driver)
+{
+       driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(modem_shm_unregister_driver);
+
+int modem_shm_register_device(struct shm_dev *dev)
+{
+       int err;
+
+       dev->dev.bus = &shm_bus;
+       err = device_register(&dev->dev);
+       return err;
+}
+EXPORT_SYMBOL_GPL(modem_shm_register_device);
+
+void modem_shm_unregister_device(struct shm_dev *dev)
+{
+       device_unregister(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(modem_shm_unregister_device);
+
+static int shm_bus_init(void)
+{
+       if (bus_register(&shm_bus) != 0)
+               panic("shm bus registration failed");
+       return 0;
+}
+
+static void __exit shm_bus_exit(void)
+{
+       bus_unregister(&shm_bus);
+}
+
+core_initcall(shm_bus_init);
+module_exit(shm_bus_exit);