media: microchip: microchip-isc: prepare for media controller support

Prepare the support for media-controller.
This means that the capabilities of the driver have changed and now it's
capable of media controller operations.
The driver will register its media device, and add the video entity to this
media device. The subdevices are registered to the same media device.
The ISC will have a base entity which is auto-detected as
microchip_isc_base.
It will also register a subdevice that allows cropping of the incoming
frame to the maximum frame size supported by the ISC.
The ISC will create a link between the subdevice that is asynchronously
registered and the microchip_isc_scaler entity.
Then, the microchip_isc_scaler and microchip_isc_base are connected
through another link.
This patch does not change the previous capability of the driver, the
fact that the format is still being propagated from the top video node
down to the sensor.

Signed-off-by: Eugen Hristev <[e-mail]>
Reviewed-by: Jacopo Mondi <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/microchip/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
 microchip-isc-objs = microchip-sama5d2-isc.o
 microchip-xisc-objs = microchip-sama7g5-isc.o
-microchip-isc-common-objs = microchip-isc-base.o microchip-isc-clk.o
+microchip-isc-common-objs = microchip-isc-base.o microchip-isc-clk.o microchip-isc-scaler.o
 
 obj-$(CONFIG_VIDEO_MICROCHIP_ISC_BASE) += microchip-isc-common.o
 obj-$(CONFIG_VIDEO_MICROCHIP_ISC) += microchip-isc.o

drivers/media/platform/microchip/microchip-isc-base.c

···
 					      struct isc_device, v4l2_dev);
 	struct isc_subdev_entity *subdev_entity =
 		container_of(notifier, struct isc_subdev_entity, notifier);
+	int pad;
 
 	if (video_is_registered(&isc->video_dev)) {
 		v4l2_err(&isc->v4l2_dev, "only supports one sub-device.\n");
···
 	}
 
 	subdev_entity->sd = subdev;
+
+	pad = media_entity_get_fwnode_pad(&subdev->entity, asd->match.fwnode,
+					  MEDIA_PAD_FL_SOURCE);
+	if (pad < 0) {
+		v4l2_err(&isc->v4l2_dev, "failed to find pad for %s\n",
+			 subdev->name);
+		return pad;
+	}
+
+	isc->remote_pad = pad;
 
 	return 0;
 }
···
 	v4l2_ctrl_handler_free(&isc->ctrls.handler);
 }
 
-static struct isc_format *find_format_by_code(struct isc_device *isc,
-					      unsigned int code, int *index)
+struct isc_format *isc_find_format_by_code(struct isc_device *isc,
+					   unsigned int code, int *index)
 {
 	struct isc_format *fmt = &isc->formats_list[0];
 	unsigned int i;
···
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(isc_find_format_by_code);
 
 static int isc_formats_init(struct isc_device *isc)
 {
···
 				 NULL, &mbus_code)) {
 		mbus_code.index++;
 
-		fmt = find_format_by_code(isc, mbus_code.code, &i);
+		fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
 		if (!fmt) {
 			v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
 				  mbus_code.code);
···
 		goto isc_async_complete_err;
 	}
 
+	ret = isc_scaler_link(isc);
+	if (ret < 0)
+		goto isc_async_complete_unregister_device;
+
+	ret = media_device_register(&isc->mdev);
+	if (ret < 0)
+		goto isc_async_complete_unregister_device;
+
 	return 0;
+
+isc_async_complete_unregister_device:
+	video_unregister_device(vdev);
 
 isc_async_complete_err:
 	mutex_destroy(&isc->awb_mutex);
···
 	return 0;
 }
 EXPORT_SYMBOL_GPL(microchip_isc_pipeline_init);
+
+int isc_mc_init(struct isc_device *isc, u32 ver)
+{
+	const struct of_device_id *match;
+	int ret;
+
+	isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
+	isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
+	isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+
+	ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
+				     isc->pads);
+	if (ret < 0) {
+		dev_err(isc->dev, "media entity init failed\n");
+		return ret;
+	}
+
+	isc->mdev.dev = isc->dev;
+
+	match = of_match_node(isc->dev->driver->of_match_table,
+			      isc->dev->of_node);
+
+	strscpy(isc->mdev.driver_name, KBUILD_MODNAME,
+		sizeof(isc->mdev.driver_name));
+	strscpy(isc->mdev.model, match->compatible, sizeof(isc->mdev.model));
+	snprintf(isc->mdev.bus_info, sizeof(isc->mdev.bus_info), "platform:%s",
+		 isc->v4l2_dev.name);
+	isc->mdev.hw_revision = ver;
+
+	media_device_init(&isc->mdev);
+
+	isc->v4l2_dev.mdev = &isc->mdev;
+
+	return isc_scaler_init(isc);
+}
+EXPORT_SYMBOL_GPL(isc_mc_init);
+
+void isc_mc_cleanup(struct isc_device *isc)
+{
+	media_entity_cleanup(&isc->video_dev.entity);
+	media_device_cleanup(&isc->mdev);
+}
+EXPORT_SYMBOL_GPL(isc_mc_cleanup);
 
 /* regmap configuration */
 #define MICROCHIP_ISC_REG_MAX    0xd5c

drivers/media/platform/microchip/microchip-isc-scaler.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Microchip Image Sensor Controller (ISC) Scaler entity support
+ *
+ * Copyright (C) 2022 Microchip Technology, Inc.
+ *
+ * Author: Eugen Hristev <[e-mail]>
+ *
+ */
+
+#include <media/media-device.h>
+#include <media/media-entity.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+#include "microchip-isc-regs.h"
+#include "microchip-isc.h"
+
+static void isc_scaler_prepare_fmt(struct v4l2_mbus_framefmt *framefmt)
+{
+	framefmt->colorspace = V4L2_COLORSPACE_SRGB;
+	framefmt->field = V4L2_FIELD_NONE;
+	framefmt->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+	framefmt->quantization = V4L2_QUANTIZATION_DEFAULT;
+	framefmt->xfer_func = V4L2_XFER_FUNC_DEFAULT;
+};
+
+static int isc_scaler_get_fmt(struct v4l2_subdev *sd,
+			      struct v4l2_subdev_state *sd_state,
+			      struct v4l2_subdev_format *format)
+{
+	struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
+	struct v4l2_mbus_framefmt *v4l2_try_fmt;
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
+		v4l2_try_fmt = v4l2_subdev_get_try_format(sd, sd_state,
+							  format->pad);
+		format->format = *v4l2_try_fmt;
+
+		return 0;
+	}
+
+	format->format = isc->scaler_format[format->pad];
+
+	return 0;
+}
+
+static int isc_scaler_set_fmt(struct v4l2_subdev *sd,
+			      struct v4l2_subdev_state *sd_state,
+			      struct v4l2_subdev_format *req_fmt)
+{
+	struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
+	struct v4l2_mbus_framefmt *v4l2_try_fmt;
+	struct isc_format *fmt;
+	unsigned int i;
+
+	/* Source format is fixed, we cannot change it */
+	if (req_fmt->pad == ISC_SCALER_PAD_SOURCE) {
+		req_fmt->format = isc->scaler_format[ISC_SCALER_PAD_SOURCE];
+		return 0;
+	}
+
+	/* There is no limit on the frame size on the sink pad */
+	v4l_bound_align_image(&req_fmt->format.width, 16, UINT_MAX, 0,
+			      &req_fmt->format.height, 16, UINT_MAX, 0, 0);
+
+	isc_scaler_prepare_fmt(&req_fmt->format);
+
+	fmt = isc_find_format_by_code(isc, req_fmt->format.code, &i);
+
+	if (!fmt)
+		fmt = &isc->formats_list[0];
+
+	req_fmt->format.code = fmt->mbus_code;
+
+	if (req_fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		v4l2_try_fmt = v4l2_subdev_get_try_format(sd, sd_state,
+							  req_fmt->pad);
+		*v4l2_try_fmt = req_fmt->format;
+		/* Trying on the sink pad makes the source pad change too */
+		v4l2_try_fmt = v4l2_subdev_get_try_format(sd, sd_state,
+							  ISC_SCALER_PAD_SOURCE);
+		*v4l2_try_fmt = req_fmt->format;
+
+		v4l_bound_align_image(&v4l2_try_fmt->width,
+				      16, isc->max_width, 0,
+				      &v4l2_try_fmt->height,
+				      16, isc->max_height, 0, 0);
+		/* if we are just trying, we are done */
+		return 0;
+	}
+
+	isc->scaler_format[ISC_SCALER_PAD_SINK] = req_fmt->format;
+
+	/* The source pad is the same as the sink, but we have to crop it */
+	isc->scaler_format[ISC_SCALER_PAD_SOURCE] =
+		isc->scaler_format[ISC_SCALER_PAD_SINK];
+	v4l_bound_align_image
+		(&isc->scaler_format[ISC_SCALER_PAD_SOURCE].width, 16,
+		 isc->max_width, 0,
+		 &isc->scaler_format[ISC_SCALER_PAD_SOURCE].height, 16,
+		 isc->max_height, 0, 0);
+
+	return 0;
+}
+
+static int isc_scaler_enum_mbus_code(struct v4l2_subdev *sd,
+				     struct v4l2_subdev_state *sd_state,
+				     struct v4l2_subdev_mbus_code_enum *code)
+{
+	struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
+
+	/*
+	 * All formats supported by the ISC are supported by the scaler.
+	 * Advertise the formats which the ISC can take as input, as the scaler
+	 * entity cropping is part of the PFE module (parallel front end)
+	 */
+	if (code->index < isc->formats_list_size) {
+		code->code = isc->formats_list[code->index].mbus_code;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int isc_scaler_g_sel(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_state *sd_state,
+			    struct v4l2_subdev_selection *sel)
+{
+	struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
+
+	if (sel->pad == ISC_SCALER_PAD_SOURCE)
+		return -EINVAL;
+
+	if (sel->target != V4L2_SEL_TGT_CROP_BOUNDS &&
+	    sel->target != V4L2_SEL_TGT_CROP)
+		return -EINVAL;
+
+	sel->r.height = isc->scaler_format[ISC_SCALER_PAD_SOURCE].height;
+	sel->r.width = isc->scaler_format[ISC_SCALER_PAD_SOURCE].width;
+
+	sel->r.left = 0;
+	sel->r.top = 0;
+
+	return 0;
+}
+
+static int isc_scaler_init_cfg(struct v4l2_subdev *sd,
+			       struct v4l2_subdev_state *sd_state)
+{
+	struct v4l2_mbus_framefmt *v4l2_try_fmt =
+		v4l2_subdev_get_try_format(sd, sd_state, 0);
+	struct v4l2_rect *try_crop;
+	struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
+
+	*v4l2_try_fmt = isc->scaler_format[ISC_SCALER_PAD_SOURCE];
+
+	try_crop = v4l2_subdev_get_try_crop(sd, sd_state, 0);
+
+	try_crop->top = 0;
+	try_crop->left = 0;
+	try_crop->width = v4l2_try_fmt->width;
+	try_crop->height = v4l2_try_fmt->height;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
+	.enum_mbus_code = isc_scaler_enum_mbus_code,
+	.set_fmt = isc_scaler_set_fmt,
+	.get_fmt = isc_scaler_get_fmt,
+	.get_selection = isc_scaler_g_sel,
+	.init_cfg = isc_scaler_init_cfg,
+};
+
+static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
+	.pad = &isc_scaler_pad_ops,
+};
+
+int isc_scaler_init(struct isc_device *isc)
+{
+	int ret;
+
+	v4l2_subdev_init(&isc->scaler_sd, &xisc_scaler_subdev_ops);
+
+	isc->scaler_sd.owner = THIS_MODULE;
+	isc->scaler_sd.dev = isc->dev;
+	snprintf(isc->scaler_sd.name, sizeof(isc->scaler_sd.name),
+		 "microchip_isc_scaler");
+
+	isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
+	isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+	isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+
+	isc_scaler_prepare_fmt(&isc->scaler_format[ISC_SCALER_PAD_SOURCE]);
+	isc->scaler_format[ISC_SCALER_PAD_SOURCE].height = isc->max_height;
+	isc->scaler_format[ISC_SCALER_PAD_SOURCE].width = isc->max_width;
+	isc->scaler_format[ISC_SCALER_PAD_SOURCE].code =
+		 isc->formats_list[0].mbus_code;
+
+	isc->scaler_format[ISC_SCALER_PAD_SINK] =
+		 isc->scaler_format[ISC_SCALER_PAD_SOURCE];
+
+	ret = media_entity_pads_init(&isc->scaler_sd.entity,
+				     ISC_SCALER_PADS_NUM,
+				     isc->scaler_pads);
+	if (ret < 0) {
+		dev_err(isc->dev, "scaler sd media entity init failed\n");
+		return ret;
+	}
+
+	ret = v4l2_device_register_subdev(&isc->v4l2_dev, &isc->scaler_sd);
+	if (ret < 0) {
+		dev_err(isc->dev, "scaler sd failed to register subdev\n");
+		return ret;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(isc_scaler_init);
+
+int isc_scaler_link(struct isc_device *isc)
+{
+	int ret;
+
+	ret = media_create_pad_link(&isc->current_subdev->sd->entity,
+				    isc->remote_pad, &isc->scaler_sd.entity,
+				    ISC_SCALER_PAD_SINK,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+
+	if (ret < 0) {
+		dev_err(isc->dev, "Failed to create pad link: %s to %s\n",
+			isc->current_subdev->sd->entity.name,
+			isc->scaler_sd.entity.name);
+		return ret;
+	}
+
+	dev_dbg(isc->dev, "link with %s pad: %d\n",
+		isc->current_subdev->sd->name, isc->remote_pad);
+
+	ret = media_create_pad_link(&isc->scaler_sd.entity,
+				    ISC_SCALER_PAD_SOURCE,
+				    &isc->video_dev.entity, ISC_PAD_SINK,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+
+	if (ret < 0) {
+		dev_err(isc->dev, "Failed to create pad link: %s to %s\n",
+			isc->scaler_sd.entity.name,
+			isc->video_dev.entity.name);
+		return ret;
+	}
+
+	dev_dbg(isc->dev, "link with %s pad: %d\n", isc->scaler_sd.name,
+		ISC_SCALER_PAD_SOURCE);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(isc_scaler_link);
+

drivers/media/platform/microchip/microchip-isc.h

···
 	u32 his_entry;
 };
 
+enum isc_mc_pads {
+	ISC_PAD_SINK	= 0,
+	ISC_PADS_NUM	= 1,
+};
+
+enum isc_scaler_pads {
+	ISC_SCALER_PAD_SINK	= 0,
+	ISC_SCALER_PAD_SOURCE	= 1,
+	ISC_SCALER_PADS_NUM	= 2,
+};
+
 /*
  * struct isc_device - ISC device driver data/config struct
  * @regmap:		Register map
···
  *			be used as an input to the controller
  * @controller_formats_size:	size of controller_formats array
  * @formats_list_size:	size of formats_list array
+ * @pads:		media controller pads for isc video entity
+ * @mdev:		media device that is registered by the isc
+ * @remote_pad:		remote pad on the connected subdevice
+ * @scaler_sd:		subdevice for the scaler that isc registers
+ * @scaler_pads:	media controller pads for the scaler subdevice
+ * @scaler_format:	current format for the scaler subdevice
  */
 struct isc_device {
 	struct regmap		*regmap;
···
 	struct isc_format		*formats_list;
 	u32				controller_formats_size;
 	u32				formats_list_size;
+
+	struct {
+		struct media_pad		pads[ISC_PADS_NUM];
+		struct media_device		mdev;
+
+		u32				remote_pad;
+	};
+
+	struct {
+		struct v4l2_subdev		scaler_sd;
+		struct media_pad		scaler_pads[ISC_SCALER_PADS_NUM];
+		struct v4l2_mbus_framefmt	scaler_format[ISC_SCALER_PADS_NUM];
+	};
 };
 
 extern const struct regmap_config microchip_isc_regmap_config;
···
 void microchip_isc_subdev_cleanup(struct isc_device *isc);
 void microchip_isc_clk_cleanup(struct isc_device *isc);
 
+int isc_scaler_link(struct isc_device *isc);
+int isc_scaler_init(struct isc_device *isc);
+int isc_mc_init(struct isc_device *isc, u32 ver);
+void isc_mc_cleanup(struct isc_device *isc);
+
+struct isc_format *isc_find_format_by_code(struct isc_device *isc,
+					   unsigned int code, int *index);
 #endif

drivers/media/platform/microchip/microchip-sama5d2-isc.c

···
 			break;
 	}
 
+	regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
+
+	ret = isc_mc_init(isc, ver);
+	if (ret < 0)
+		goto isc_probe_mc_init_err;
+
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
 	pm_request_idle(dev);
···
 		goto unprepare_clk;
 	}
 
-	regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
 	dev_info(dev, "Microchip ISC version %x\n", ver);
 
 	return 0;
···
 
 disable_pm:
 	pm_runtime_disable(dev);
+
+isc_probe_mc_init_err:
+	isc_mc_cleanup(isc);
 
 cleanup_subdev:
 	microchip_isc_subdev_cleanup(isc);
···
 	struct isc_device *isc = platform_get_drvdata(pdev);
 
 	pm_runtime_disable(&pdev->dev);
+
+	isc_mc_cleanup(isc);
 
 	microchip_isc_subdev_cleanup(isc);
 

drivers/media/platform/microchip/microchip-sama7g5-isc.c

···
 			break;
 	}
 
+	regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
+
+	ret = isc_mc_init(isc, ver);
+	if (ret < 0)
+		goto isc_probe_mc_init_err;
+
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
 	pm_request_idle(dev);
 
-	regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
 	dev_info(dev, "Microchip XISC version %x\n", ver);
 
 	return 0;
+
+isc_probe_mc_init_err:
+	isc_mc_cleanup(isc);
 
 cleanup_subdev:
 	microchip_isc_subdev_cleanup(isc);
···
 	struct isc_device *isc = platform_get_drvdata(pdev);
 
 	pm_runtime_disable(&pdev->dev);
+
+	isc_mc_cleanup(isc);
 
 	microchip_isc_subdev_cleanup(isc);