V4L/DVB (7170): soc_camera V4L2 driver for directly-connected SoC-based cameras

This driver provides an interface between platform-specific camera
busses and camera devices. It should be used if the camera is connected
not over a "proper" bus like PCI or USB, but over a special bus, like,
for example, the Quick Capture interface on PXA270 SoCs. Later it should
also be used for i.MX31 SoCs from Freescale.  It can handle multiple
cameras and / or multiple busses, which can be used, e.g., in
stereo-vision applications.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/Kconfig

@@ -836,4 +836,13 @@ config USB_STKWEBCAM
 
 endif # V4L_USB_DRIVERS
 
+config SOC_CAMERA
+	tristate "SoC camera support"
+	depends on VIDEO_V4L2
+	select VIDEOBUF_DMA_SG
+	help
+	  SoC Camera is a common API to several cameras, not connecting
+	  over a bus like PCI or USB. For example some i2c camera connected
+	  directly to the data bus of an SoC.
+
 endif # VIDEO_CAPTURE_DRIVERS

drivers/media/video/Makefile

@@ -136,5 +136,7 @@ obj-$(CONFIG_VIDEO_IVTV) += ivtv/
 obj-$(CONFIG_VIDEO_VIVI) += vivi.o
 obj-$(CONFIG_VIDEO_CX23885) += cx23885/
 
+obj-$(CONFIG_SOC_CAMERA)	+= soc_camera.o
+
 EXTRA_CFLAGS += -Idrivers/media/dvb/dvb-core
 EXTRA_CFLAGS += -Idrivers/media/dvb/frontends

include/media/soc_camera.h

+/*
+ * camera image capture (abstract) bus driver header
+ *
+ * Copyright (C) 2006, Sascha Hauer, Pengutronix
+ * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
+ *
+ * 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.
+ */
+
+#ifndef SOC_CAMERA_H
+#define SOC_CAMERA_H
+
+#include <linux/videodev2.h>
+#include <media/videobuf-dma-sg.h>
+
+struct soc_camera_device {
+	struct list_head list;
+	struct device dev;
+	struct device *control;
+	unsigned short width;		/* Current window */
+	unsigned short height;		/* sizes */
+	unsigned short x_min;		/* Camera capabilities */
+	unsigned short y_min;
+	unsigned short x_current;	/* Current window location */
+	unsigned short y_current;
+	unsigned short width_min;
+	unsigned short width_max;
+	unsigned short height_min;
+	unsigned short height_max;
+	unsigned short y_skip_top;	/* Lines to skip at the top */
+	unsigned short gain;
+	unsigned short exposure;
+	unsigned char iface;		/* Host number */
+	unsigned char devnum;		/* Device number per host */
+	unsigned char cached_datawidth;	/* See comment in .c */
+	struct soc_camera_ops *ops;
+	struct video_device *vdev;
+	const struct soc_camera_data_format *current_fmt;
+	int (*probe)(struct soc_camera_device *icd);
+	void (*remove)(struct soc_camera_device *icd);
+	struct module *owner;
+};
+
+struct soc_camera_file {
+	struct soc_camera_device *icd;
+	struct videobuf_queue vb_vidq;
+};
+
+struct soc_camera_host {
+	struct list_head list;
+	struct device dev;
+	unsigned char nr;				/* Host number */
+	size_t msize;
+	struct videobuf_queue_ops *vbq_ops;
+	struct module *owner;
+	void *priv;
+	char *drv_name;
+	int (*add)(struct soc_camera_device *);
+	void (*remove)(struct soc_camera_device *);
+	int (*set_capture_format)(struct soc_camera_device *, __u32,
+				  struct v4l2_rect *);
+	int (*try_fmt_cap)(struct soc_camera_host *, struct v4l2_format *);
+	int (*reqbufs)(struct soc_camera_file *, struct v4l2_requestbuffers *);
+	int (*querycap)(struct soc_camera_host *, struct v4l2_capability *);
+	unsigned int (*poll)(struct file *, poll_table *);
+};
+
+struct soc_camera_link {
+	/* Camera bus id, used to match a camera and a bus */
+	int bus_id;
+	/* GPIO number to switch between 8 and 10 bit modes */
+	unsigned int gpio;
+};
+
+static inline struct soc_camera_device *to_soc_camera_dev(struct device *dev)
+{
+	return container_of(dev, struct soc_camera_device, dev);
+}
+
+static inline struct soc_camera_host *to_soc_camera_host(struct device *dev)
+{
+	return container_of(dev, struct soc_camera_host, dev);
+}
+
+extern int soc_camera_host_register(struct soc_camera_host *ici,
+				     struct module *owner);
+extern void soc_camera_host_unregister(struct soc_camera_host *ici);
+extern int soc_camera_device_register(struct soc_camera_device *icd);
+extern void soc_camera_device_unregister(struct soc_camera_device *icd);
+
+extern int soc_camera_video_start(struct soc_camera_device *icd);
+extern void soc_camera_video_stop(struct soc_camera_device *icd);
+
+struct soc_camera_data_format {
+	char *name;
+	unsigned int depth;
+	__u32 fourcc;
+	enum v4l2_colorspace colorspace;
+};
+
+struct soc_camera_ops {
+	struct module *owner;
+	int (*init)(struct soc_camera_device *);
+	int (*release)(struct soc_camera_device *);
+	int (*start_capture)(struct soc_camera_device *);
+	int (*stop_capture)(struct soc_camera_device *);
+	int (*set_capture_format)(struct soc_camera_device *, __u32,
+				  struct v4l2_rect *, unsigned int);
+	int (*try_fmt_cap)(struct soc_camera_device *, struct v4l2_format *);
+	int (*get_chip_id)(struct soc_camera_device *,
+			   struct v4l2_chip_ident *);
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	int (*get_register)(struct soc_camera_device *, struct v4l2_register *);
+	int (*set_register)(struct soc_camera_device *, struct v4l2_register *);
+#endif
+	const struct soc_camera_data_format *formats;
+	int num_formats;
+	int (*get_control)(struct soc_camera_device *, struct v4l2_control *);
+	int (*set_control)(struct soc_camera_device *, struct v4l2_control *);
+	const struct v4l2_queryctrl *controls;
+	int num_controls;
+	unsigned int(*get_datawidth)(struct soc_camera_device *icd);
+};
+
+static inline struct v4l2_queryctrl const *soc_camera_find_qctrl(
+	struct soc_camera_ops *ops, int id)
+{
+	int i;
+
+	for (i = 0; i < ops->num_controls; i++)
+		if (ops->controls[i].id == id)
+			return &ops->controls[i];
+
+	return NULL;
+}
+
+#define IS_MASTER		(1<<0)
+#define IS_HSYNC_ACTIVE_HIGH	(1<<1)
+#define IS_VSYNC_ACTIVE_HIGH	(1<<2)
+#define IS_DATAWIDTH_8		(1<<3)
+#define IS_DATAWIDTH_9		(1<<4)
+#define IS_DATAWIDTH_10		(1<<5)
+#define IS_PCLK_SAMPLE_RISING	(1<<6)
+
+#endif