1 files changed, 334 insertions, 0 deletions

diff --git a/drivers/media/platform/video-mux.c b/drivers/media/platform/video-mux.c
new file mode 100644
index 000000000000..665744716f73
--- /dev/null
+++ b/drivers/media/platform/video-mux.c
@@ -0,0 +1,334 @@
+/*
+ * video stream multiplexer controlled via mux control
+ *
+ * Copyright (C) 2013 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
+ * Copyright (C) 2016-2017 Pengutronix, Philipp Zabel <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
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+struct video_mux {
+	struct v4l2_subdev subdev;
+	struct media_pad *pads;
+	struct v4l2_mbus_framefmt *format_mbus;
+	struct regmap_field *field;
+	struct mutex lock;
+	int active;
+};
+
+static inline struct video_mux *v4l2_subdev_to_video_mux(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct video_mux, subdev);
+}
+
+static int video_mux_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 video_mux *vmux = v4l2_subdev_to_video_mux(sd);
+	int ret = 0;
+
+	/*
+	 * The mux state is determined by the enabled sink pad link.
+	 * Enabling or disabling the source pad link has no effect.
+	 */
+	if (local->flags & MEDIA_PAD_FL_SOURCE)
+		return 0;
+
+	dev_dbg(sd->dev, "link setup '%s':%d->'%s':%d[%d]",
+		remote->entity->name, remote->index, local->entity->name,
+		local->index, flags & MEDIA_LNK_FL_ENABLED);
+
+	mutex_lock(&vmux->lock);
+
+	if (flags & MEDIA_LNK_FL_ENABLED) {
+		if (vmux->active == local->index)
+			goto out;
+
+		if (vmux->active >= 0) {
+			ret = -EBUSY;
+			goto out;
+		}
+
+		dev_dbg(sd->dev, "setting %d active\n", local->index);
+		ret = regmap_field_write(vmux->field, local->index);
+		if (ret < 0)
+			goto out;
+		vmux->active = local->index;
+	} else {
+		if (vmux->active != local->index)
+			goto out;
+
+		dev_dbg(sd->dev, "going inactive\n");
+		vmux->active = -1;
+	}
+
+out:
+	mutex_unlock(&vmux->lock);
+	return ret;
+}
+
+static const struct media_entity_operations video_mux_ops = {
+	.link_setup = video_mux_link_setup,
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int video_mux_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
+	struct v4l2_subdev *upstream_sd;
+	struct media_pad *pad;
+
+	if (vmux->active == -1) {
+		dev_err(sd->dev, "Can not start streaming on inactive mux\n");
+		return -EINVAL;
+	}
+
+	pad = media_entity_remote_pad(&sd->entity.pads[vmux->active]);
+	if (!pad) {
+		dev_err(sd->dev, "Failed to find remote source pad\n");
+		return -ENOLINK;
+	}
+
+	if (!is_media_entity_v4l2_subdev(pad->entity)) {
+		dev_err(sd->dev, "Upstream entity is not a v4l2 subdev\n");
+		return -ENODEV;
+	}
+
+	upstream_sd = media_entity_to_v4l2_subdev(pad->entity);
+
+	return v4l2_subdev_call(upstream_sd, video, s_stream, enable);
+}
+
+static const struct v4l2_subdev_video_ops video_mux_subdev_video_ops = {
+	.s_stream = video_mux_s_stream,
+};
+
+static struct v4l2_mbus_framefmt *
+__video_mux_get_pad_format(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   unsigned int pad, u32 which)
+{
+	struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
+
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_format(sd, cfg, pad);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &vmux->format_mbus[pad];
+	default:
+		return NULL;
+	}
+}
+
+static int video_mux_get_format(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_pad_config *cfg,
+			    struct v4l2_subdev_format *sdformat)
+{
+	struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
+
+	mutex_lock(&vmux->lock);
+
+	sdformat->format = *__video_mux_get_pad_format(sd, cfg, sdformat->pad,
+						       sdformat->which);
+
+	mutex_unlock(&vmux->lock);
+
+	return 0;
+}
+
+static int video_mux_set_format(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_pad_config *cfg,
+			    struct v4l2_subdev_format *sdformat)
+{
+	struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
+	struct v4l2_mbus_framefmt *mbusformat;
+	struct media_pad *pad = &vmux->pads[sdformat->pad];
+
+	mbusformat = __video_mux_get_pad_format(sd, cfg, sdformat->pad,
+					    sdformat->which);
+	if (!mbusformat)
+		return -EINVAL;
+
+	mutex_lock(&vmux->lock);
+
+	/* Source pad mirrors active sink pad, no limitations on sink pads */
+	if ((pad->flags & MEDIA_PAD_FL_SOURCE) && vmux->active >= 0)
+		sdformat->format = vmux->format_mbus[vmux->active];
+
+	*mbusformat = sdformat->format;
+
+	mutex_unlock(&vmux->lock);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops video_mux_pad_ops = {
+	.get_fmt = video_mux_get_format,
+	.set_fmt = video_mux_set_format,
+};
+
+static const struct v4l2_subdev_ops video_mux_subdev_ops = {
+	.pad = &video_mux_pad_ops,
+	.video = &video_mux_subdev_video_ops,
+};
+
+static int video_mux_probe_mmio_mux(struct video_mux *vmux)
+{
+	struct device *dev = vmux->subdev.dev;
+	struct of_phandle_args args;
+	struct reg_field field;
+	struct regmap *regmap;
+	u32 reg, mask;
+	int ret;
+
+	ret = of_parse_phandle_with_args(dev->of_node, "mux-controls",
+					 "#mux-control-cells", 0, &args);
+	if (ret)
+		return ret;
+
+	if (!of_device_is_compatible(args.np, "mmio-mux"))
+		return -EINVAL;
+
+	regmap = syscon_node_to_regmap(args.np->parent);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ret = of_property_read_u32_index(args.np, "mux-reg-masks",
+					 2 * args.args[0], &reg);
+	if (!ret)
+		ret = of_property_read_u32_index(args.np, "mux-reg-masks",
+						 2 * args.args[0] + 1, &mask);
+	if (ret < 0)
+		return ret;
+
+	field.reg = reg;
+	field.msb = fls(mask) - 1;
+	field.lsb = ffs(mask) - 1;
+
+	vmux->field = devm_regmap_field_alloc(dev, regmap, field);
+	if (IS_ERR(vmux->field))
+		return PTR_ERR(vmux->field);
+
+	return 0;
+}
+
+static int video_mux_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct device_node *ep;
+	struct video_mux *vmux;
+	unsigned int num_pads = 0;
+	int ret;
+	int i;
+
+	vmux = devm_kzalloc(dev, sizeof(*vmux), GFP_KERNEL);
+	if (!vmux)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, vmux);
+
+	v4l2_subdev_init(&vmux->subdev, &video_mux_subdev_ops);
+	snprintf(vmux->subdev.name, sizeof(vmux->subdev.name), "%s", np->name);
+	vmux->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	vmux->subdev.dev = dev;
+
+	/*
+	 * The largest numbered port is the output port. It determines
+	 * total number of pads.
+	 */
+	for_each_endpoint_of_node(np, ep) {
+		struct of_endpoint endpoint;
+
+		of_graph_parse_endpoint(ep, &endpoint);
+		num_pads = max(num_pads, endpoint.port + 1);
+	}
+
+	if (num_pads < 2) {
+		dev_err(dev, "Not enough ports %d\n", num_pads);
+		return -EINVAL;
+	}
+
+	ret = video_mux_probe_mmio_mux(vmux);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get mux: %d\n", ret);
+		return ret;
+	}
+
+	mutex_init(&vmux->lock);
+	vmux->active = -1;
+	vmux->pads = devm_kcalloc(dev, num_pads, sizeof(*vmux->pads),
+				  GFP_KERNEL);
+	vmux->format_mbus = devm_kcalloc(dev, num_pads,
+					 sizeof(*vmux->format_mbus),
+					 GFP_KERNEL);
+
+	for (i = 0; i < num_pads - 1; i++)
+		vmux->pads[i].flags = MEDIA_PAD_FL_SINK;
+	vmux->pads[num_pads - 1].flags = MEDIA_PAD_FL_SOURCE;
+
+	vmux->subdev.entity.function = MEDIA_ENT_F_VID_MUX;
+	ret = media_entity_pads_init(&vmux->subdev.entity, num_pads,
+				     vmux->pads);
+	if (ret < 0)
+		return ret;
+
+	vmux->subdev.entity.ops = &video_mux_ops;
+
+	return v4l2_async_register_subdev(&vmux->subdev);
+}
+
+static int video_mux_remove(struct platform_device *pdev)
+{
+	struct video_mux *vmux = platform_get_drvdata(pdev);
+	struct v4l2_subdev *sd = &vmux->subdev;
+
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+
+	return 0;
+}
+
+static const struct of_device_id video_mux_dt_ids[] = {
+	{ .compatible = "video-mux", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, video_mux_dt_ids);
+
+static struct platform_driver video_mux_driver = {
+	.probe		= video_mux_probe,
+	.remove		= video_mux_remove,
+	.driver		= {
+		.of_match_table = video_mux_dt_ids,
+		.name = "video-mux",
+	},
+};
+
+module_platform_driver(video_mux_driver);
+
+MODULE_DESCRIPTION("video stream multiplexer");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_AUTHOR("Philipp Zabel, Pengutronix");
+MODULE_LICENSE("GPL");