V4L/DVB (6451): v4l2: add support for bus-based I2C drivers

Two new headers were added: one for I2C drivers that are only used
by V4L2 drivers converted to the new bus-based I2C API, and one that
can be used by both converted and unconverted drivers (at the expense of
some additional overhead).

To support the legacy I2C API a helper function was added to v4l2-common.c.

These headers take care of all the 'boilerplate' code that all V4L2 I2C drivers
have in common and will automatically support the bus-based I2C API introduced
in kernel 2.6.22.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/include/media/v4l2-i2c-drv.h b/include/media/v4l2-i2c-drv.h
new file mode 100644
index 000000000000..547db60d3640
--- /dev/null
+++ b/include/media/v4l2-i2c-drv.h
@@ -0,0 +1,61 @@
+/*
+ * v4l2-i2c-drv.h - contains I2C handling code that's identical for
+ *		    all V4L2 I2C drivers. Use this header if the
+ *		    I2C driver is only used by drivers converted
+ *		    to the bus-based I2C API.
+ *
+ * Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+struct v4l2_i2c_driver_data {
+	const char * const name;
+	int driverid;
+	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
+	int (*probe)(struct i2c_client *client);
+	int (*remove)(struct i2c_client *client);
+	int (*suspend)(struct i2c_client *client, pm_message_t state);
+	int (*resume)(struct i2c_client *client);
+	int legacy_class;
+};
+
+static struct v4l2_i2c_driver_data v4l2_i2c_data;
+static struct i2c_client_address_data addr_data;
+static struct i2c_driver v4l2_i2c_driver;
+
+
+/* Bus-based I2C implementation for kernels >= 2.6.22 */
+
+static int __init v4l2_i2c_drv_init(void)
+{
+	v4l2_i2c_driver.driver.name = v4l2_i2c_data.name;
+	v4l2_i2c_driver.id = v4l2_i2c_data.driverid;
+	v4l2_i2c_driver.command = v4l2_i2c_data.command;
+	v4l2_i2c_driver.probe = v4l2_i2c_data.probe;
+	v4l2_i2c_driver.remove = v4l2_i2c_data.remove;
+	v4l2_i2c_driver.suspend = v4l2_i2c_data.suspend;
+	v4l2_i2c_driver.resume = v4l2_i2c_data.resume;
+	return i2c_add_driver(&v4l2_i2c_driver);
+}
+
+
+static void __exit v4l2_i2c_drv_cleanup(void)
+{
+	i2c_del_driver(&v4l2_i2c_driver);
+}
+
+module_init(v4l2_i2c_drv_init);
+module_exit(v4l2_i2c_drv_cleanup);