自学教程：C++ v4l2_get_subdevdata函数代码示例

static int gsc_capture_subdev_set_fmt(struct v4l2_subdev *sd,				      struct v4l2_subdev_fh *fh,				      struct v4l2_subdev_format *fmt){	struct gsc_dev *gsc = v4l2_get_subdevdata(sd);	struct v4l2_mbus_framefmt *mf;	struct gsc_ctx *ctx = gsc->cap.ctx;	struct gsc_frame *frame;	mf = __gsc_cap_get_format(gsc, fh, fmt->pad, fmt->which);	if (mf == NULL)		return -EINVAL;	gsc_cap_try_format(gsc, fh, fmt->pad, &fmt->format, fmt->which);	*mf = fmt->format;	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)		return 0;	frame = gsc_capture_get_frame(ctx, fmt->pad);	if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {		frame->crop.left = 0;		frame->crop.top = 0;		frame->f_width = mf->width;		frame->f_height = mf->height;		frame->crop.width = mf->width;		frame->crop.height = mf->height;	}	gsc_dbg("offs_h : %d, offs_v : %d, f_width : %d, f_height :%d,/				width : %d, height : %d", frame->crop.left,/				frame->crop.top, frame->f_width,				frame->f_height,/				frame->crop.width, frame->crop.height);	return 0;}

static int gsc_capture_link_setup(struct media_entity *entity,				  const struct media_pad *local,				  const struct media_pad *remote, u32 flags){	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);	struct gsc_dev *gsc = v4l2_get_subdevdata(sd);	struct gsc_capture_device *cap = &gsc->cap;	gsc_info("");	switch (local->index | media_entity_type(remote->entity)) {	case GSC_PAD_SINK | MEDIA_ENT_T_V4L2_SUBDEV:		if (flags & MEDIA_LNK_FL_ENABLED) {			if (cap->input != 0)				return -EBUSY;			/* Write-Back link enabled */			if (!strcmp(remote->entity->name, FIMD_MODULE_NAME)) {				gsc->cap.sd_disp =					media_entity_to_v4l2_subdev(remote->entity);				gsc->cap.sd_disp->grp_id = FIMD_GRP_ID;				cap->ctx->in_path = GSC_WRITEBACK;				cap->input |= GSC_IN_FIMD_WRITEBACK;			} else if (remote->index == FLITE_PAD_SOURCE_PREV) {				cap->input |= GSC_IN_FLITE_PREVIEW;			} else {				cap->input |= GSC_IN_FLITE_CAMCORDING;			}		} else {			cap->input = GSC_IN_NONE;		}		break;	case GSC_PAD_SOURCE | MEDIA_ENT_T_DEVNODE:		/* gsc-cap always write to memory */		break;	}	return 0;}

static int resetctrl_reset(struct v4l2_subdev *sd, u32 val){	struct cx18 *cx = v4l2_get_subdevdata(sd);	const struct cx18_gpio_i2c_slave_reset *p;	p = &cx->card->gpio_i2c_slave_reset;	switch (val) {	case CX18_GPIO_RESET_I2C:		gpio_reset_seq(cx, p->active_lo_mask, p->active_hi_mask,			       p->msecs_asserted, p->msecs_recovery);		break;	case CX18_GPIO_RESET_Z8F0811:		/*		 * Assert timing for the Z8F0811 on HVR-1600 boards:		 * 1. Assert RESET for min of 4 clock cycles at 18.432 MHz to		 *    initiate		 * 2. Reset then takes 66 WDT cycles at 10 kHz + 16 xtal clock		 *    cycles (6,601,085 nanoseconds ~= 7 milliseconds)		 * 3. DBG pin must be high before chip exits reset for normal		 *    operation.  DBG is open drain and hopefully pulled high		 *    since we don't normally drive it (GPIO 1?) for the		 *    HVR-1600		 * 4. Z8F0811 won't exit reset until RESET is deasserted		 * 5. Zilog comes out of reset, loads reset vector address and		 *    executes from there. Required recovery delay unknown.		 */		gpio_reset_seq(cx, p->ir_reset_mask, 0,			       p->msecs_asserted, p->msecs_recovery);		break;	case CX18_GPIO_RESET_XC2028:		if (cx->card->tuners[0].tuner == TUNER_XC2028)			gpio_reset_seq(cx, (1 << cx->card->xceive_pin), 0,				       1, 1);		break;	}	return 0;}

static int aksensor_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a){	struct i2c_client *client = v4l2_get_subdevdata(sd);	struct aksensor_priv *priv = to_aksensor(client);	int ret = -EINVAL;	T_BOOL bRet = AK_FALSE;		sensor_dbg("entry %s/n", __func__);		priv->win.width = a->c.width;	priv->win.height =a->c.height;			switch (g_mode)	{		case CAMERA_WMODE_PREV:			if (cur_sensor_info->handler->cam_set_to_prev_func != NULL)				bRet = cur_sensor_info->handler->cam_set_to_prev_func(a->c.width, a->c.height);			break;		case CAMERA_WMODE_CAP:			if (cur_sensor_info->handler->cam_set_to_cap_func != NULL)				bRet = cur_sensor_info->handler->cam_set_to_cap_func(a->c.width, a->c.height);			break;		case CAMERA_WMODE_REC:			if (cur_sensor_info->handler->cam_set_to_record_func != NULL)				bRet = cur_sensor_info->handler->cam_set_to_record_func(a->c.width, a->c.height);			break;		default :			if (cur_sensor_info->handler->cam_set_to_record_func != NULL)				bRet = cur_sensor_info->handler->cam_set_to_record_func(a->c.width, a->c.height);			break;	}	if ( bRet )		ret = 0;		return ret;}

static int aksensor_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a){	struct i2c_client *client = v4l2_get_subdevdata(sd);	struct aksensor_priv *priv = to_aksensor(client); 	int i;	sensor_dbg("entry %s. priv=%p/n", __func__, priv);	for (i = 0; i < cur_sensor_info->num_resolution; ++i) {		if (!strcmp(cur_sensor_info->resolution[i].name, "720P")) 			break;	}	// the resolution is 720P or larger	if (i == cur_sensor_info->num_resolution)		--i;	a->bounds.width	= cur_sensor_info->resolution[i].width;	a->bounds.height = cur_sensor_info->resolution[i].height;	a->bounds.left			= 0;	a->bounds.top			= 0;			a->defrect.width		= priv->win.width;	a->defrect.height		= priv->win.height;	a->defrect.left			= 0;	a->defrect.top			= 0;		a->type					= V4L2_BUF_TYPE_VIDEO_CAPTURE;	a->pixelaspect.numerator	= 1;	a->pixelaspect.denominator	= 1;	sensor_dbg("%s./n"				"	a->bounds.width=%d, a->bounds.height=%d/n"				"	a->defrect.width=%d, a->defrect.height=%d/n",				__func__, 				a->bounds.width, a->bounds.height,				a->defrect.width, a->defrect.height);	return 0;}

static int msm_csiphy_init(struct v4l2_subdev *sd){	int rc = 0;	struct csiphy_device *csiphy_dev;	csiphy_dev = v4l2_get_subdevdata(sd);	if (csiphy_dev == NULL) {		rc = -ENOMEM;		return rc;	}	csiphy_dev->base = ioremap(csiphy_dev->mem->start,		resource_size(csiphy_dev->mem));	if (!csiphy_dev->base) {		rc = -ENOMEM;		return rc;	}	rc = msm_cam_clk_enable(&csiphy_dev->pdev->dev, csiphy_clk_info,			csiphy_dev->csiphy_clk, ARRAY_SIZE(csiphy_clk_info), 1);	if (rc < 0) {		iounmap(csiphy_dev->base);		csiphy_dev->base = NULL;		return rc;	}#if DBG_CSIPHY	rc = request_irq(new_csiphy_dev->irq->start, msm_csiphy_irq,		IRQF_TRIGGER_RISING, "csiphy", new_csiphy_dev);	if (rc < 0) {		pr_err("%s: irq request fail/n", __func__);		return -EBUSY;	}#endif	return 0;}

static int mt9v011_read(struct v4l2_subdev *sd, unsigned char addr){	struct i2c_client *c = v4l2_get_subdevdata(sd);	__be16 buffer;	int rc, val;	rc = i2c_master_send(c, &addr, 1);	if (rc != 1)		v4l2_dbg(0, debug, sd,			 "i2c i/o error: rc == %d (should be 1)/n", rc);	msleep(10);	rc = i2c_master_recv(c, (char *)&buffer, 2);	if (rc != 2)		v4l2_dbg(0, debug, sd,			 "i2c i/o error: rc == %d (should be 2)/n", rc);	val = be16_to_cpu(buffer);	v4l2_dbg(2, debug, sd, "mt9v011: read 0x%02x = 0x%04x/n", addr, val);	return val;}