V4L/DVB (9820): v4l2: add v4l2_device and v4l2_subdev structs to the v4l2 framework.

Start implementing a proper v4l2 framework as discussed during the
Linux Plumbers Conference 2008.

Introduces v4l2_device (for device instances) and v4l2_subdev (representing
sub-device instances).

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Reviewed-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Andy Walls <awalls@radix.net>
Reviewed-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 297 insertions, 0 deletions

diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
new file mode 100644
index 00000000000..97b283a0428
--- /dev/null
+++ b/include/media/v4l2-device.h
@@ -0,0 +1,109 @@
+/*
+    V4L2 device support header.
+
+    Copyright (C) 2008  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _V4L2_DEVICE_H
+#define _V4L2_DEVICE_H
+
+#include <media/v4l2-subdev.h>
+
+/* Each instance of a V4L2 device should create the v4l2_device struct,
+   either stand-alone or embedded in a larger struct.
+
+   It allows easy access to sub-devices (see v4l2-subdev.h) and provides
+   basic V4L2 device-level support.
+ */
+
+#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)
+
+struct v4l2_device {
+	/* dev->driver_data points to this struct */
+	struct device *dev;
+	/* used to keep track of the registered subdevs */
+	struct list_head subdevs;
+	/* lock this struct; can be used by the driver as well if this
+	   struct is embedded into a larger struct. */
+	spinlock_t lock;
+	/* unique device name, by default the driver name + bus ID */
+	char name[V4L2_DEVICE_NAME_SIZE];
+};
+
+/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */
+int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
+/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */
+void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
+
+/* Register a subdev with a v4l2 device. While registered the subdev module
+   is marked as in-use. An error is returned if the module is no longer
+   loaded when you attempt to register it. */
+int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd);
+/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
+   wasn't registered. In that case it will do nothing. */
+void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
+
+/* Iterate over all subdevs. */
+#define v4l2_device_for_each_subdev(sd, dev)				\
+	list_for_each_entry(sd, &(dev)->subdevs, list)
+
+/* Call the specified callback for all subdevs matching the condition.
+   Ignore any errors. Note that you cannot add or delete a subdev
+   while walking the subdevs list. */
+#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) 		\
+	do { 								\
+		struct v4l2_subdev *sd; 				\
+									\
+		list_for_each_entry(sd, &(dev)->subdevs, list)   	\
+			if ((cond) && sd->ops->o && sd->ops->o->f) 	\
+				sd->ops->o->f(sd , ##args); 		\
+	} while (0)
+
+/* Call the specified callback for all subdevs matching the condition.
+   If the callback returns an error other than 0 or -ENOIOCTLCMD, then
+   return with that error code. Note that you cannot add or delete a
+   subdev while walking the subdevs list. */
+#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...)  \
+({ 									\
+	struct v4l2_subdev *sd; 					\
+	int err = 0; 							\
+									\
+	list_for_each_entry(sd, &(dev)->subdevs, list) { 		\
+		if ((cond) && sd->ops->o && sd->ops->o->f) 		\
+			err = sd->ops->o->f(sd , ##args); 		\
+		if (err && err != -ENOIOCTLCMD)				\
+			break; 						\
+	} 								\
+	(err == -ENOIOCTLCMD) ? 0 : err; 				\
+})
+
+/* Call the specified callback for all subdevs matching grp_id (if 0, then
+   match them all). Ignore any errors. Note that you cannot add or delete
+   a subdev while walking the subdevs list. */
+#define v4l2_device_call_all(dev, grp_id, o, f, args...) 		\
+	__v4l2_device_call_subdevs(dev, 				\
+			!(grp_id) || sd->grp_id == (grp_id), o, f , ##args)
+
+/* Call the specified callback for all subdevs matching grp_id (if 0, then
+   match them all). If the callback returns an error other than 0 or
+   -ENOIOCTLCMD, then return with that error code. Note that you cannot
+   add or delete a subdev while walking the subdevs list. */
+#define v4l2_device_call_until_err(dev, grp_id, o, f, args...) 		\
+	__v4l2_device_call_subdevs_until_err(dev,			\
+		       !(grp_id) || sd->grp_id == (grp_id), o, f , ##args)
+
+#endif
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
new file mode 100644
index 00000000000..bc9e0fbf282
--- /dev/null
+++ b/include/media/v4l2-subdev.h
@@ -0,0 +1,188 @@
+/*
+    V4L2 sub-device support header.
+
+    Copyright (C) 2008  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _V4L2_SUBDEV_H
+#define _V4L2_SUBDEV_H
+
+#include <media/v4l2-common.h>
+
+struct v4l2_device;
+struct v4l2_subdev;
+struct tuner_setup;
+
+/* Sub-devices are devices that are connected somehow to the main bridge
+   device. These devices are usually audio/video muxers/encoders/decoders or
+   sensors and webcam controllers.
+
+   Usually these devices are controlled through an i2c bus, but other busses
+   may also be used.
+
+   The v4l2_subdev struct provides a way of accessing these devices in a
+   generic manner. Most operations that these sub-devices support fall in
+   a few categories: core ops, audio ops, video ops and tuner ops.
+
+   More categories can be added if needed, although this should remain a
+   limited set (no more than approx. 8 categories).
+
+   Each category has its own set of ops that subdev drivers can implement.
+
+   A subdev driver can leave the pointer to the category ops NULL if
+   it does not implement them (e.g. an audio subdev will generally not
+   implement the video category ops). The exception is the core category:
+   this must always be present.
+
+   These ops are all used internally so it is no problem to change, remove
+   or add ops or move ops from one to another category. Currently these
+   ops are based on the original ioctls, but since ops are not limited to
+   one argument there is room for improvement here once all i2c subdev
+   drivers are converted to use these ops.
+ */
+
+/* Core ops: it is highly recommended to implement at least these ops:
+
+   g_chip_ident
+   log_status
+   g_register
+   s_register
+
+   This provides basic debugging support.
+
+   The ioctl ops is meant for generic ioctl-like commands. Depending on
+   the use-case it might be better to use subdev-specific ops (currently
+   not yet implemented) since ops provide proper type-checking.
+ */
+struct v4l2_subdev_core_ops {
+	int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_chip_ident *chip);
+	int (*log_status)(struct v4l2_subdev *sd);
+	int (*init)(struct v4l2_subdev *sd, u32 val);
+	int (*s_standby)(struct v4l2_subdev *sd, u32 standby);
+	int (*reset)(struct v4l2_subdev *sd, u32 val);
+	int (*s_gpio)(struct v4l2_subdev *sd, u32 val);
+	int (*queryctrl)(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
+	int (*g_ctrl)(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
+	int (*s_ctrl)(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
+	int (*querymenu)(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
+	int (*ioctl)(struct v4l2_subdev *sd, int cmd, void *arg);
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	int (*g_register)(struct v4l2_subdev *sd, struct v4l2_register *reg);
+	int (*s_register)(struct v4l2_subdev *sd, struct v4l2_register *reg);
+#endif
+};
+
+struct v4l2_subdev_tuner_ops {
+	int (*s_mode)(struct v4l2_subdev *sd, enum v4l2_tuner_type);
+	int (*s_radio)(struct v4l2_subdev *sd);
+	int (*s_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq);
+	int (*g_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq);
+	int (*g_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt);
+	int (*s_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt);
+	int (*s_std)(struct v4l2_subdev *sd, v4l2_std_id norm);
+	int (*s_type_addr)(struct v4l2_subdev *sd, struct tuner_setup *type);
+	int (*s_config)(struct v4l2_subdev *sd, const struct v4l2_priv_tun_config *config);
+};
+
+struct v4l2_subdev_audio_ops {
+	int (*s_clock_freq)(struct v4l2_subdev *sd, u32 freq);
+	int (*s_i2s_clock_freq)(struct v4l2_subdev *sd, u32 freq);
+	int (*s_routing)(struct v4l2_subdev *sd, const struct v4l2_routing *route);
+};
+
+struct v4l2_subdev_video_ops {
+	int (*s_routing)(struct v4l2_subdev *sd, const struct v4l2_routing *route);
+	int (*s_crystal_freq)(struct v4l2_subdev *sd, struct v4l2_crystal_freq *freq);
+	int (*decode_vbi_line)(struct v4l2_subdev *sd, struct v4l2_decode_vbi_line *vbi_line);
+	int (*s_vbi_data)(struct v4l2_subdev *sd, const struct v4l2_sliced_vbi_data *vbi_data);
+	int (*g_vbi_data)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_data *vbi_data);
+	int (*s_std_output)(struct v4l2_subdev *sd, v4l2_std_id std);
+	int (*s_stream)(struct v4l2_subdev *sd, int enable);
+	int (*s_fmt)(struct v4l2_subdev *sd, struct v4l2_format *fmt);
+	int (*g_fmt)(struct v4l2_subdev *sd, struct v4l2_format *fmt);
+};
+
+struct v4l2_subdev_ops {
+	const struct v4l2_subdev_core_ops  *core;
+	const struct v4l2_subdev_tuner_ops *tuner;
+	const struct v4l2_subdev_audio_ops *audio;
+	const struct v4l2_subdev_video_ops *video;
+};
+
+#define V4L2_SUBDEV_NAME_SIZE 32
+
+/* Each instance of a subdev driver should create this struct, either
+   stand-alone or embedded in a larger struct.
+ */
+struct v4l2_subdev {
+	struct list_head list;
+	struct module *owner;
+	struct v4l2_device *dev;
+	const struct v4l2_subdev_ops *ops;
+	/* name must be unique */
+	char name[V4L2_SUBDEV_NAME_SIZE];
+	/* can be used to group similar subdevs, value is driver-specific */
+	u32 grp_id;
+	/* pointer to private data */
+	void *priv;
+};
+
+static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)
+{
+	sd->priv = p;
+}
+
+static inline void *v4l2_get_subdevdata(const struct v4l2_subdev *sd)
+{
+	return sd->priv;
+}
+
+/* Convert an ioctl-type command to the proper v4l2_subdev_ops function call.
+   This is used by subdev modules that can be called by both old-style ioctl
+   commands and through the v4l2_subdev_ops.
+
+   The ioctl API of the subdev driver can call this function to call the
+   right ops based on the ioctl cmd and arg.
+
+   Once all subdev drivers have been converted and all drivers no longer
+   use the ioctl interface, then this function can be removed.
+ */
+int v4l2_subdev_command(struct v4l2_subdev *sd, unsigned cmd, void *arg);
+
+static inline void v4l2_subdev_init(struct v4l2_subdev *sd,
+					const struct v4l2_subdev_ops *ops)
+{
+	INIT_LIST_HEAD(&sd->list);
+	/* ops->core MUST be set */
+	BUG_ON(!ops || !ops->core);
+	sd->ops = ops;
+	sd->dev = NULL;
+	sd->name[0] = '\0';
+	sd->grp_id = 0;
+	sd->priv = NULL;
+}
+
+/* Call an ops of a v4l2_subdev, doing the right checks against
+   NULL pointers.
+
+   Example: err = v4l2_subdev_call(sd, core, g_chip_ident, &chip);
+ */
+#define v4l2_subdev_call(sd, o, f, args...)				\
+	(!(sd) ? -ENODEV : (((sd) && (sd)->ops->o && (sd)->ops->o->f) ?	\
+		(sd)->ops->o->f((sd) , ##args) : -ENOIOCTLCMD))
+
+#endif