V4L/DVB (5862): V4L: Add internal ioctl-like interface.

This patch adds an internal ioctl-like interface which can be used in
situations where a single Video4Linux device is implemented by multiple
device drivers. One master device controls one or more slave devices.
The slaves provide Video4Linux ioctl-like interface for the use of the
master.

Only a handful of ioctls are implemented at the moment. More can (and
should) be added as more functionality is required.

Signed-off-by: Sakari Ailus <sakari.ailus@nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 210 insertions, 0 deletions

diff --git a/include/media/v4l2-int-device.h b/include/media/v4l2-int-device.h
new file mode 100644
index 00000000000..2b6fc1122f6
--- /dev/null
+++ b/include/media/v4l2-int-device.h
@@ -0,0 +1,210 @@
+/*
+ * include/media/v4l2-int-device.h
+ *
+ * V4L2 internal ioctl interface.
+ *
+ * Copyright (C) 2007 Nokia Corporation.
+ *
+ * Contact: Sakari Ailus <sakari.ailus@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef V4L2_INT_DEVICE_H
+#define V4L2_INT_DEVICE_H
+
+#include <linux/module.h>
+#include <media/v4l2-common.h>
+
+#define V4L2NAMESIZE 32
+
+enum v4l2_int_type {
+	v4l2_int_type_master = 1,
+	v4l2_int_type_slave
+};
+
+enum v4l2_int_ioctl_num {
+	/*
+	 *
+	 * "Proper" V4L ioctls, as in struct video_device.
+	 *
+	 */
+	vidioc_int_enum_fmt_cap_num = 1,
+	vidioc_int_g_fmt_cap_num,
+	vidioc_int_s_fmt_cap_num,
+	vidioc_int_try_fmt_cap_num,
+	vidioc_int_queryctrl_num,
+	vidioc_int_g_ctrl_num,
+	vidioc_int_s_ctrl_num,
+	vidioc_int_g_parm_num,
+	vidioc_int_s_parm_num,
+
+	/*
+	 *
+	 * Strictly internal ioctls.
+	 *
+	 */
+	/* Initialise the device when slave attaches to the master. */
+	vidioc_int_dev_init_num = 1000,
+	/* Delinitialise the device at slave detach. */
+	vidioc_int_dev_exit_num,
+	/* Set device power state: 0 is off, non-zero is on. */
+	vidioc_int_s_power_num,
+	/* Get parallel interface clock speed for current settings. */
+	vidioc_int_g_ext_clk_num,
+	/*
+	 * Tell what the parallel interface clock speed actually is.
+	 */
+	vidioc_int_s_ext_clk_num,
+	/* Does the slave need to be reset after VIDIOC_DQBUF? */
+	vidioc_int_g_needs_reset_num,
+
+	/*
+	 *
+	 * VIDIOC_INT_* ioctls.
+	 *
+	 */
+	/* VIDIOC_INT_RESET */
+	vidioc_int_reset_num,
+	/* VIDIOC_INT_INIT */
+	vidioc_int_init_num,
+	/* VIDIOC_INT_G_CHIP_IDENT */
+	vidioc_int_g_chip_ident_num,
+
+	/*
+	 *
+	 * Start of private ioctls.
+	 *
+	 */
+	vidioc_int_priv_start_num = 2000,
+};
+
+struct v4l2_int_device;
+
+struct v4l2_int_master {
+	int (*attach)(struct v4l2_int_device *master,
+		      struct v4l2_int_device *slave);
+	void (*detach)(struct v4l2_int_device *master);
+};
+
+typedef int (v4l2_int_ioctl_func)(struct v4l2_int_device *);
+typedef int (v4l2_int_ioctl_func_0)(struct v4l2_int_device *);
+typedef int (v4l2_int_ioctl_func_1)(struct v4l2_int_device *, void *);
+
+struct v4l2_int_ioctl_desc {
+	int num;
+	v4l2_int_ioctl_func *func;
+};
+
+struct v4l2_int_slave {
+	/* Don't touch master. */
+	struct v4l2_int_device *master;
+
+	char attach_to[V4L2NAMESIZE];
+
+	int num_ioctls;
+	struct v4l2_int_ioctl_desc *ioctls;
+};
+
+struct v4l2_int_device {
+	/* Don't touch head. */
+	struct list_head head;
+
+	struct module *module;
+
+	char name[V4L2NAMESIZE];
+
+	enum v4l2_int_type type;
+	union {
+		struct v4l2_int_master *master;
+		struct v4l2_int_slave *slave;
+	} u;
+
+	void *priv;
+};
+
+int v4l2_int_device_register(struct v4l2_int_device *d);
+void v4l2_int_device_unregister(struct v4l2_int_device *d);
+
+int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd);
+int v4l2_int_ioctl_1(struct v4l2_int_device *d, int cmd, void *arg);
+
+/*
+ *
+ * IOCTL wrapper functions for better type checking.
+ *
+ */
+
+#define V4L2_INT_WRAPPER_0(name)					\
+	static inline int vidioc_int_##name(struct v4l2_int_device *d)	\
+	{								\
+		return v4l2_int_ioctl_0(d, vidioc_int_##name##_num);	\
+	}								\
+									\
+	static inline struct v4l2_int_ioctl_desc			\
+	vidioc_int_##name##_cb(int (*func)				\
+			       (struct v4l2_int_device *))		\
+	{								\
+		struct v4l2_int_ioctl_desc desc;			\
+									\
+		desc.num = vidioc_int_##name##_num;			\
+		desc.func = (v4l2_int_ioctl_func *)func;		\
+									\
+		return desc;						\
+	}
+
+#define V4L2_INT_WRAPPER_1(name, arg_type, asterisk)			\
+	static inline int vidioc_int_##name(struct v4l2_int_device *d,	\
+					    arg_type asterisk arg)	\
+	{								\
+		return v4l2_int_ioctl_1(d, vidioc_int_##name##_num,	\
+					(void *)arg);			\
+	}								\
+									\
+	static inline struct v4l2_int_ioctl_desc			\
+	vidioc_int_##name##_cb(int (*func)				\
+			       (struct v4l2_int_device *,		\
+				arg_type asterisk))			\
+	{								\
+		struct v4l2_int_ioctl_desc desc;			\
+									\
+		desc.num = vidioc_int_##name##_num;			\
+		desc.func = (v4l2_int_ioctl_func *)func;		\
+									\
+		return desc;						\
+	}
+
+V4L2_INT_WRAPPER_1(enum_fmt_cap, struct v4l2_fmtdesc, *);
+V4L2_INT_WRAPPER_1(g_fmt_cap, struct v4l2_format, *);
+V4L2_INT_WRAPPER_1(s_fmt_cap, struct v4l2_format, *);
+V4L2_INT_WRAPPER_1(try_fmt_cap, struct v4l2_format, *);
+V4L2_INT_WRAPPER_1(queryctrl, struct v4l2_queryctrl, *);
+V4L2_INT_WRAPPER_1(g_ctrl, struct v4l2_control, *);
+V4L2_INT_WRAPPER_1(s_ctrl, struct v4l2_control, *);
+V4L2_INT_WRAPPER_1(g_parm, struct v4l2_streamparm, *);
+V4L2_INT_WRAPPER_1(s_parm, struct v4l2_streamparm, *);
+
+V4L2_INT_WRAPPER_0(dev_init);
+V4L2_INT_WRAPPER_0(dev_exit);
+V4L2_INT_WRAPPER_1(s_power, int, );
+V4L2_INT_WRAPPER_1(s_ext_clk, u32, );
+V4L2_INT_WRAPPER_1(g_ext_clk, u32, *);
+V4L2_INT_WRAPPER_1(g_needs_reset, void, *);
+
+V4L2_INT_WRAPPER_0(reset);
+V4L2_INT_WRAPPER_0(init);
+V4L2_INT_WRAPPER_1(g_chip_ident, int, *);
+
+#endif