sh-mobile-ceu-camera: implement host-side cropping

From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

Not all video capture devices can configure arbitrary cropping, whereas the
CEU module on SuperH CPUs can crop with pixel precision. However, we want to
use camera cropping if possible to save bandwidth and increase the frame-rate.
This patch verifies whether the camera managed to crop exactly the requested
rectangle, and if not, uses host-side cropping. To be able to crop on CEU we
have to preserve camera rectangle too, for which the host_priv member in
struct soc_camera_device is used. We now allocate memory dynamically, thus we
have to use the .put_formats() method from struct soc_camera_host_ops to free
it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Priority: low
---
 drivers/media/video/sh_mobile_ceu_camera.c |  309 +++++++++++++++++++++++-----
 1 files changed, 259 insertions(+), 50 deletions(-)

1 files changed, 259 insertions, 50 deletions

diff --git a/linux/drivers/media/video/sh_mobile_ceu_camera.c b/linux/drivers/media/video/sh_mobile_ceu_camera.c
index f54a9f23f..befc84ce1 100644
--- a/linux/drivers/media/video/sh_mobile_ceu_camera.c
+++ b/linux/drivers/media/video/sh_mobile_ceu_camera.c
@@ -94,10 +94,17 @@ struct sh_mobile_ceu_dev {
 	spinlock_t lock;
 	struct list_head capture;
 	struct videobuf_buffer *active;
-	int is_interlaced;
 
 	struct sh_mobile_ceu_info *pdata;
 
+	unsigned int is_interlaced:1;
+	unsigned int image_mode:1;
+	unsigned int is_16bit:1;
+};
+
+struct sh_mobile_ceu_cam {
+	struct v4l2_rect camera_rect;
+	const struct soc_camera_data_format *extra_fmt;
 	const struct soc_camera_data_format *camera_fmt;
 };
 
@@ -430,14 +437,101 @@ static void sh_mobile_ceu_remove_device(struct soc_camera_device *icd)
 	pcdev->icd = NULL;
 }
 
+static void sh_mobile_ceu_set_rect(struct soc_camera_device *icd,
+				   struct v4l2_rect *rect)
+{
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct sh_mobile_ceu_cam *cam = icd->host_priv;
+	struct sh_mobile_ceu_dev *pcdev = ici->priv;
+	int width, height, cfszr_width, cdwdr_width;
+	unsigned int left_offset, top_offset;
+	u32 camor;
+
+	if (rect->left > cam->camera_rect.left) {
+		left_offset = rect->left - cam->camera_rect.left;
+	} else {
+		left_offset = 0;
+		rect->left = cam->camera_rect.left;
+	}
+
+	if (rect->top > cam->camera_rect.top) {
+		top_offset = rect->top - cam->camera_rect.top;
+	} else {
+		top_offset = 0;
+		rect->top = cam->camera_rect.top;
+	}
+
+	dev_dbg(&icd->dev, "Offsets %u:%u\n", left_offset, top_offset);
+
+	if (pcdev->image_mode) {
+		width = rect->width;
+		if (!pcdev->is_16bit)
+			width *= 2;
+		cfszr_width = cdwdr_width = rect->width;
+	} else {
+		width = rect->width *
+			((icd->current_fmt->depth + 7) >> 3);
+		width = pcdev->is_16bit ? width / 2 : width;
+		cfszr_width = pcdev->is_16bit ? width : width / 2;
+		cdwdr_width = pcdev->is_16bit ? width * 2 : width;
+	}
+
+	height = rect->height;
+	if (pcdev->is_interlaced) {
+		height /= 2;
+		cdwdr_width *= 2;
+	}
+
+	camor = left_offset | (top_offset << 16);
+	ceu_write(pcdev, CAMOR, camor);
+	ceu_write(pcdev, CAPWR, (height << 16) | width);
+	ceu_write(pcdev, CFSZR, (height << 16) | cfszr_width);
+	ceu_write(pcdev, CDWDR, cdwdr_width);
+}
+
+static u32 capture_save_reset(struct sh_mobile_ceu_dev *pcdev)
+{
+	u32 capsr = ceu_read(pcdev, CAPSR);
+	ceu_write(pcdev, CAPSR, 1 << 16); /* reset, stop capture */
+	return capsr;
+}
+
+static void capture_restore(struct sh_mobile_ceu_dev *pcdev, u32 capsr)
+{
+	unsigned long timeout = jiffies + 10 * HZ;
+
+	/*
+	 * Wait until the end of the current frame. It can take a long time,
+	 * but if it has been aborted by a CAPSR reset, it shoule exit sooner.
+	 */
+	while ((ceu_read(pcdev, CSTSR) & 1) && time_before(jiffies, timeout))
+		msleep(1);
+
+	if (time_after(jiffies, timeout)) {
+		dev_err(pcdev->ici.v4l2_dev.dev,
+			"Timeout waiting for frame end! Interface problem?\n");
+		return;
+	}
+
+	/* Wait until reset clears, this shall not hang... */
+	while (ceu_read(pcdev, CAPSR) & (1 << 16))
+		udelay(10);
+
+	/* Anything to restore? */
+	if (capsr & ~(1 << 16))
+		ceu_write(pcdev, CAPSR, capsr);
+}
+
 static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
 				       __u32 pixfmt)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct sh_mobile_ceu_dev *pcdev = ici->priv;
-	int ret, buswidth, width, height, cfszr_width, cdwdr_width;
+	int ret;
 	unsigned long camera_flags, common_flags, value;
-	int yuv_mode, yuv_lineskip;
+	int yuv_lineskip;
+	struct sh_mobile_ceu_cam *cam = icd->host_priv;
+	u32 capsr = capture_save_reset(pcdev);
 
 	camera_flags = icd->ops->query_bus_param(icd);
 	common_flags = soc_camera_bus_param_compatible(camera_flags,
@@ -451,10 +545,10 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
 
 	switch (common_flags & SOCAM_DATAWIDTH_MASK) {
 	case SOCAM_DATAWIDTH_8:
-		buswidth = 8;
+		pcdev->is_16bit = 0;
 		break;
 	case SOCAM_DATAWIDTH_16:
-		buswidth = 16;
+		pcdev->is_16bit = 1;
 		break;
 	default:
 		return -EINVAL;
@@ -464,7 +558,7 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
 	ceu_write(pcdev, CRCMPR, 0);
 
 	value = 0x00000010; /* data fetch by default */
-	yuv_mode = yuv_lineskip = 0;
+	pcdev->image_mode = yuv_lineskip = 0;
 
 	switch (icd->current_fmt->fourcc) {
 	case V4L2_PIX_FMT_NV12:
@@ -473,8 +567,8 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
 		/* fall-through */
 	case V4L2_PIX_FMT_NV16:
 	case V4L2_PIX_FMT_NV61:
-		yuv_mode = 1;
-		switch (pcdev->camera_fmt->fourcc) {
+		pcdev->image_mode = 1;
+		switch (cam->camera_fmt->fourcc) {
 		case V4L2_PIX_FMT_UYVY:
 			value = 0x00000000; /* Cb0, Y0, Cr0, Y1 */
 			break;
@@ -498,36 +592,16 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
 
 	value |= common_flags & SOCAM_VSYNC_ACTIVE_LOW ? 1 << 1 : 0;
 	value |= common_flags & SOCAM_HSYNC_ACTIVE_LOW ? 1 << 0 : 0;
-	value |= buswidth == 16 ? 1 << 12 : 0;
+	value |= pcdev->is_16bit ? 1 << 12 : 0;
 	ceu_write(pcdev, CAMCR, value);
 
 	ceu_write(pcdev, CAPCR, 0x00300000);
 	ceu_write(pcdev, CAIFR, pcdev->is_interlaced ? 0x101 : 0);
 
 	mdelay(1);
+	sh_mobile_ceu_set_rect(icd, &icd->rect_current);
 
-	if (yuv_mode) {
-		width = icd->rect_current.width * 2;
-		width = buswidth == 16 ? width / 2 : width;
-		cfszr_width = cdwdr_width = icd->rect_current.width;
-	} else {
-		width = icd->rect_current.width *
-			((icd->current_fmt->depth + 7) >> 3);
-		width = buswidth == 16 ? width / 2 : width;
-		cfszr_width = buswidth == 8 ? width / 2 : width;
-		cdwdr_width = buswidth == 16 ? width * 2 : width;
-	}
-
-	height = icd->rect_current.height;
-	if (pcdev->is_interlaced) {
-		height /= 2;
-		cdwdr_width *= 2;
-	}
-
-	ceu_write(pcdev, CAMOR, 0);
-	ceu_write(pcdev, CAPWR, (height << 16) | width);
 	ceu_write(pcdev, CFLCR, 0); /* no scaling */
-	ceu_write(pcdev, CFSZR, (height << 16) | cfszr_width);
 
 	/* A few words about byte order (observed in Big Endian mode)
 	 *
@@ -546,10 +620,16 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
 		value &= ~0x00000010; /* convert 4:2:2 -> 4:2:0 */
 
 	ceu_write(pcdev, CDOCR, value);
-
-	ceu_write(pcdev, CDWDR, cdwdr_width);
 	ceu_write(pcdev, CFWCR, 0); /* keep "datafetch firewall" disabled */
 
+	dev_dbg(&icd->dev, "S_FMT successful for %c%c%c%c %ux%u@%u.%u\n",
+		pixfmt & 0xff, (pixfmt >> 8) & 0xff,
+		(pixfmt >> 16) & 0xff, (pixfmt >> 24) & 0xff,
+		icd->rect_current.width, icd->rect_current.height,
+		icd->rect_current.left, icd->rect_current.top);
+
+	capture_restore(pcdev, capsr);
+
 	/* not in bundle mode: skip CBDSR, CDAYR2, CDACR2, CDBYR2, CDBCR2 */
 	return 0;
 }
@@ -602,21 +682,32 @@ static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, int idx,
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	int ret, k, n;
 	int formats = 0;
+	struct sh_mobile_ceu_cam *cam;
 
 	ret = sh_mobile_ceu_try_bus_param(icd);
 	if (ret < 0)
 		return 0;
 
+	if (!icd->host_priv) {
+		cam = kzalloc(sizeof(*cam), GFP_KERNEL);
+		if (!cam)
+			return -ENOMEM;
+
+		icd->host_priv = cam;
+	} else {
+		cam = icd->host_priv;
+	}
+
 	/* Beginning of a pass */
 	if (!idx)
-		icd->host_priv = NULL;
+		cam->extra_fmt = NULL;
 
 	switch (icd->formats[idx].fourcc) {
 	case V4L2_PIX_FMT_UYVY:
 	case V4L2_PIX_FMT_VYUY:
 	case V4L2_PIX_FMT_YUYV:
 	case V4L2_PIX_FMT_YVYU:
-		if (icd->host_priv)
+		if (cam->extra_fmt)
 			goto add_single_format;
 
 		/*
@@ -628,7 +719,7 @@ static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, int idx,
 		 * the host_priv pointer and check whether the format you're
 		 * going to add now is already there.
 		 */
-		icd->host_priv = (void *)sh_mobile_ceu_formats;
+		cam->extra_fmt = (void *)sh_mobile_ceu_formats;
 
 		n = ARRAY_SIZE(sh_mobile_ceu_formats);
 		formats += n;
@@ -659,18 +750,130 @@ add_single_format:
 	return formats;
 }
 
+static void sh_mobile_ceu_put_formats(struct soc_camera_device *icd)
+{
+	kfree(icd->host_priv);
+	icd->host_priv = NULL;
+}
+
+static bool is_smaller(struct v4l2_rect *r1, struct v4l2_rect *r2)
+{
+	return r1->width < r2->width || r1->height < r2->height;
+}
+
 static int sh_mobile_ceu_set_crop(struct soc_camera_device *icd,
 				  struct v4l2_rect *rect)
 {
-	return icd->ops->set_crop(icd, rect);
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct sh_mobile_ceu_dev *pcdev = ici->priv;
+	struct v4l2_rect cam_rect = *rect;
+	struct sh_mobile_ceu_cam *cam = icd->host_priv;
+	unsigned short width, height;
+	u32 capsr;
+	int ret;
+
+	capsr = capture_save_reset(pcdev);
+	dev_dbg(&icd->dev, "CAPSR %x\n", capsr);
+
+	ret = icd->ops->set_crop(icd, &cam_rect);
+	if (!ret && !memcmp(rect, &cam_rect, sizeof(*rect))) {
+		dev_dbg(&icd->dev, "Camera S_CROP successful for %ux%u@%u.%u\n",
+			cam_rect.width, cam_rect.height,
+			cam_rect.left, cam_rect.top);
+		goto ceu_set_rect;
+	}
+
+	/* Try to fix cropping, that camera hasn't managed to do */
+	dev_dbg(&icd->dev, "Fix camera S_CROP %d for %ux%u@%u.%u\n",
+		ret, cam_rect.width, cam_rect.height,
+		cam_rect.left, cam_rect.top);
+
+	/*
+	 * Popular special case - some cameras can only handle fixed sizes like
+	 * QVGA, VGA,... Take care to avoid infinite loop.
+	 */
+	width = max(cam_rect.width, 1) * 2;
+	height = max(cam_rect.height, 1) * 2;
+	while (!ret && is_smaller(&cam_rect, rect) &&
+	       (icd->rect_max.width >= width &&
+		icd->rect_max.height >= height)) {
+		cam_rect.width = width;
+		cam_rect.height = height;
+
+		if (cam_rect.width + cam_rect.left >
+		    icd->rect_max.width + icd->rect_max.left)
+			cam_rect.left = icd->rect_max.width +
+				icd->rect_max.left - cam_rect.width;
+
+		if (cam_rect.height + cam_rect.top >
+		    icd->rect_max.height + icd->rect_max.top)
+			cam_rect.top = icd->rect_max.height +
+				icd->rect_max.top - cam_rect.height;
+
+		ret = icd->ops->set_crop(icd, &cam_rect);
+		dev_dbg(&icd->dev, "Camera S_CROP %d for %ux%u@%u.%u\n",
+			ret, cam_rect.width, cam_rect.height,
+			cam_rect.left, cam_rect.top);
+		width *= 2;
+		height *= 2;
+	}
+
+	/*
+	 * If the camera failed to configure cropping, it should not modify the
+	 * rectangle
+	 */
+	if ((ret < 0 && is_smaller(&icd->rect_current, rect)) ||
+	    is_smaller(&cam_rect, rect)) {
+		/*
+		 * The camera failed to configure a suitable cropping,
+		 * we cannot use the current rectangle, set to max
+		 */
+		cam_rect = icd->rect_max;
+		ret = icd->ops->set_crop(icd, &cam_rect);
+		dev_dbg(&icd->dev, "Camera S_CROP %d for max %ux%u@%u.%u\n",
+			ret, cam_rect.width, cam_rect.height,
+			cam_rect.left, cam_rect.top);
+		if (ret < 0)
+			/* All failed, hopefully resume current capture */
+			goto resume_capture;
+	}
+
+	/* We now have a rectangle, larger than requested, let's crop */
+
+	/*
+	 * We have to preserve camera rectangle between close() / open(),
+	 * because soc-camera core calls .set_fmt() on each first open() with
+	 * last before last close() _user_ rectangle, which can be different
+	 * from camera rectangle.
+	 */
+	dev_dbg(&icd->dev, "SH S_CROP from %ux%u@%u.%u to %ux%u@%u.%u\n",
+		cam_rect.width, cam_rect.height, cam_rect.left, cam_rect.top,
+		rect->width, rect->height, rect->left, rect->top);
+
+	ret = 0;
+
+ceu_set_rect:
+	cam->camera_rect = cam_rect;
+
+	/* Set CAMOR, CAPWR, CFSZR, take care of CDWDR */
+	if (pcdev->active)
+		capsr |= 1;
+	sh_mobile_ceu_set_rect(icd, rect);
+	capture_restore(pcdev, capsr);
+
+resume_capture:
+
+	/* Even if only camera cropping succeeded */
+	return ret;
 }
 
 static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
 				 struct v4l2_format *f)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
-	struct sh_mobile_ceu_dev *pcdev = ici->priv;
-	__u32 pixfmt = f->fmt.pix.pixelformat;
+	struct sh_mobile_ceu_cam *cam = icd->host_priv;
+	struct v4l2_pix_format *pix = &f->fmt.pix;
+	__u32 pixfmt = pix->pixelformat;
 	const struct soc_camera_format_xlate *xlate;
 	int ret;
 
@@ -680,13 +883,17 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
 		return -EINVAL;
 	}
 
-	f->fmt.pix.pixelformat = xlate->cam_fmt->fourcc;
+	pix->pixelformat = xlate->cam_fmt->fourcc;
 	ret = v4l2_device_call_until_err(&ici->v4l2_dev, (__u32)icd, video, s_fmt, f);
-	f->fmt.pix.pixelformat = pixfmt;
+	pix->pixelformat = pixfmt;
 	if (!ret) {
 		icd->buswidth = xlate->buswidth;
 		icd->current_fmt = xlate->host_fmt;
-		pcdev->camera_fmt = xlate->cam_fmt;
+		cam->camera_fmt = xlate->cam_fmt;
+		cam->camera_rect.width = pix->width;
+		cam->camera_rect.height = pix->height;
+		cam->camera_rect.left = icd->rect_current.left;
+		cam->camera_rect.top = icd->rect_current.top;
 	}
 
 	return ret;
@@ -698,7 +905,8 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct sh_mobile_ceu_dev *pcdev = ici->priv;
 	const struct soc_camera_format_xlate *xlate;
-	__u32 pixfmt = f->fmt.pix.pixelformat;
+	struct v4l2_pix_format *pix = &f->fmt.pix;
+	__u32 pixfmt = pix->pixelformat;
 	int ret;
 
 	xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
@@ -709,27 +917,27 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
 
 	/* FIXME: calculate using depth and bus width */
 
-	v4l_bound_align_image(&f->fmt.pix.width, 2, 2560, 1,
-			      &f->fmt.pix.height, 4, 1920, 2, 0);
+	v4l_bound_align_image(&pix->width, 2, 2560, 1,
+			      &pix->height, 4, 1920, 2, 0);
 
-	f->fmt.pix.bytesperline = f->fmt.pix.width *
+	pix->bytesperline = pix->width *
 		DIV_ROUND_UP(xlate->host_fmt->depth, 8);
-	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
+	pix->sizeimage = pix->height * pix->bytesperline;
 
-	f->fmt.pix.pixelformat = xlate->cam_fmt->fourcc;
+	pix->pixelformat = xlate->cam_fmt->fourcc;
 
 	/* limit to sensor capabilities */
 	ret = v4l2_device_call_until_err(&ici->v4l2_dev, (__u32)icd, video, try_fmt, f);
-	f->fmt.pix.pixelformat = pixfmt;
+	pix->pixelformat = pixfmt;
 	if (ret < 0)
 		return ret;
 
-	switch (f->fmt.pix.field) {
+	switch (pix->field) {
 	case V4L2_FIELD_INTERLACED:
 		pcdev->is_interlaced = 1;
 		break;
 	case V4L2_FIELD_ANY:
-		f->fmt.pix.field = V4L2_FIELD_NONE;
+		pix->field = V4L2_FIELD_NONE;
 		/* fall-through */
 	case V4L2_FIELD_NONE:
 		pcdev->is_interlaced = 0;
@@ -858,6 +1066,7 @@ static struct soc_camera_host_ops sh_mobile_ceu_host_ops = {
 	.add		= sh_mobile_ceu_add_device,
 	.remove		= sh_mobile_ceu_remove_device,
 	.get_formats	= sh_mobile_ceu_get_formats,
+	.put_formats	= sh_mobile_ceu_put_formats,
 	.set_crop	= sh_mobile_ceu_set_crop,
 	.set_fmt	= sh_mobile_ceu_set_fmt,
 	.try_fmt	= sh_mobile_ceu_try_fmt,