path: root/drivers/media/platform/via-camera.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for the VIA Chrome integrated camera controller.
 *
 * Copyright 2009,2010 Jonathan Corbet <corbet@lwn.net>
 *
 * This work was supported by the One Laptop Per Child project
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/v4l2-image-sizes.h>
#include <media/i2c/ov7670.h>
#include <media/videobuf2-dma-sg.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/pm_qos.h>
#include <linux/via-core.h>
#include <linux/via-gpio.h>
#include <linux/via_i2c.h>

#ifdef CONFIG_X86
#include <asm/olpc.h>
#else
#define machine_is_olpc(x) 0
#endif

#include "via-camera.h"

MODULE_ALIAS("platform:viafb-camera");
MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
MODULE_DESCRIPTION("VIA framebuffer-based camera controller driver");
MODULE_LICENSE("GPL");

static bool flip_image;
module_param(flip_image, bool, 0444);
MODULE_PARM_DESC(flip_image,
		"If set, the sensor will be instructed to flip the image vertically.");

static bool override_serial;
module_param(override_serial, bool, 0444);
MODULE_PARM_DESC(override_serial,
		"The camera driver will normally refuse to load if the XO 1.5 serial port is enabled.  Set this option to force-enable the camera.");

/*
 * The structure describing our camera.
 */
enum viacam_opstate { S_IDLE = 0, S_RUNNING = 1 };

struct via_camera {
	struct v4l2_device v4l2_dev;
	struct v4l2_ctrl_handler ctrl_handler;
	struct video_device vdev;
	struct v4l2_subdev *sensor;
	struct platform_device *platdev;
	struct viafb_dev *viadev;
	struct mutex lock;
	enum viacam_opstate opstate;
	unsigned long flags;
	struct pm_qos_request qos_request;
	/*
	 * GPIO info for power/reset management
	 */
	int power_gpio;
	int reset_gpio;
	/*
	 * I/O memory stuff.
	 */
	void __iomem *mmio;	/* Where the registers live */
	void __iomem *fbmem;	/* Frame buffer memory */
	u32 fb_offset;		/* Reserved memory offset (FB) */
	/*
	 * Capture buffers and related.	 The controller supports
	 * up to three, so that's what we have here.  These buffers
	 * live in frame buffer memory, so we don't call them "DMA".
	 */
	unsigned int cb_offsets[3];	/* offsets into fb mem */
	u8 __iomem *cb_addrs[3];	/* Kernel-space addresses */
	int n_cap_bufs;			/* How many are we using? */
	struct vb2_queue vq;
	struct list_head buffer_queue;
	u32 sequence;
	/*
	 * Video format information.  sensor_format is kept in a form
	 * that we can use to pass to the sensor.  We always run the
	 * sensor in VGA resolution, though, and let the controller
	 * downscale things if need be.	 So we keep the "real*
	 * dimensions separately.
	 */
	struct v4l2_pix_format sensor_format;
	struct v4l2_pix_format user_format;
	u32 mbus_code;
};

/* buffer for one video frame */
struct via_buffer {
	/* common v4l buffer stuff -- must be first */
	struct vb2_v4l2_buffer		vbuf;
	struct list_head		queue;
};

/*
 * Yes, this is a hack, but there's only going to be one of these
 * on any system we know of.
 */
static struct via_camera *via_cam_info;

/*
 * Flag values, manipulat