[RFC/PATCH] media: Add video bus switch

Pavel Machek
2016-12-22T13:39:42Z

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N900 contains front and back camera, with a switch between the
two. This adds support for the swich component.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

--

I see this needs dts documentation, anything else than needs to be
done?

Thanks,
Pavel

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index d944421..0a99e63 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -91,6 +91,16 @@ config VIDEO_OMAP3_DEBUG
---help---
Enable debug messages on OMAP 3 camera controller driver.

+config VIDEO_BUS_SWITCH
+ tristate "Video Bus switch"
+ depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+ depends on MEDIA_CONTROLLER
+ depends on OF
+ ---help---
+ Driver for a GPIO controlled video bus switch, which is used to
+ connect two camera sensors to the same port a the image signal
+ processor.
+
config VIDEO_PXA27x
tristate "PXA27x Quick Capture Interface driver"
depends on VIDEO_DEV && VIDEO_V4L2 && HAS_DMA
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 5b3cb27..a4c9eab 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -11,6 +11,8 @@ obj-$(CONFIG_VIDEO_MMP_CAMERA) += marvell-ccic/
obj-$(CONFIG_VIDEO_OMAP3) += omap3isp/
obj-$(CONFIG_VIDEO_PXA27x) += pxa_camera.o

+obj-$(CONFIG_VIDEO_BUS_SWITCH) += video-bus-switch.o
+
obj-$(CONFIG_VIDEO_VIU) += fsl-viu.o

obj-$(CONFIG_VIDEO_VIVID) += vivid/
diff --git a/drivers/media/platform/video-bus-switch.c b/drivers/media/platform/video-bus-switch.c
new file mode 100644
index 0000000..1a5d944
--- /dev/null
+++ b/drivers/media/platform/video-bus-switch.c
@@ -0,0 +1,371 @@
+/*
+ * Generic driver for video bus switches
+ *
+ * Copyright (C) 2015 Sebastian Reichel <sre@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#define DEBUG
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/gpio/consumer.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-of.h>
+
+/*
+ * TODO:
+ * isp_subdev_notifier_complete() calls v4l2_device_register_subdev_nodes()
+ */
+
+#define CSI_SWITCH_SUBDEVS 2
+#define CSI_SWITCH_PORTS 3
+
+enum vbs_state {
+ CSI_SWITCH_DISABLED,
+ CSI_SWITCH_PORT_1,
+ CSI_SWITCH_PORT_2,
+};
+
+struct vbs_src_pads {
+ struct media_entity *src;
+ int src_pad;
+};
+
+struct vbs_data {
+ struct gpio_desc *swgpio;
+ struct v4l2_subdev subdev;
+ struct v4l2_async_notifier notifier;
+ struct media_pad pads[CSI_SWITCH_PORTS];
+ struct vbs_src_pads src_pads[CSI_SWITCH_PORTS];
+ enum vbs_state state;
+};
+
+struct vbs_async_subdev {
+ struct v4l2_subdev *sd;
+ struct v4l2_async_subdev asd;
+ u8 port;
+};
+
+static int vbs_of_parse_nodes(struct device *dev, struct vbs_data *pdata)
+{
+ struct v4l2_async_notifier *notifier = &pdata->notifier;
+ struct device_node *node = NULL;
+
+ notifier->subdevs = devm_kcalloc(dev, CSI_SWITCH_SUBDEVS,
+ sizeof(*notifier->subdevs), GFP_KERNEL);
+ if (!notifier->subdevs)
+ return -ENOMEM;
+
+ notifier->num_subdevs = 0;
+ while (notifier->num_subdevs < CSI_SWITCH_SUBDEVS &&
+ (node = of_graph_get_next_endpoint(dev->of_node, node))) {
+ struct v4l2_of_endpoint vep;
+ struct vbs_async_subdev *ssd;
+
+ /* skip first port (connected to isp) */
+ v4l2_of_parse_endpoint(node, &vep);
+ if (vep.base.port == 0) {
+ struct device_node *ispnode;
+
+ ispnode = of_graph_get_remote_port_parent(node);
+ if (!ispnode) {
+ dev_warn(dev, "bad remote port parent\n");
+ return -EINVAL;
+ }
+
+ of_node_put(node);
+ continue;
+ }
+
+ ssd = devm_kzalloc(dev, sizeof(*ssd), GFP_KERNEL);
+ if (!ssd) {
+ of_node_put(node);
+ return -ENOMEM;
+ }
+
+ ssd->port = vep.base.port;
+
+ notifier->subdevs[notifier->num_subdevs] = &ssd->asd;
+
+ ssd->asd.match.of.node = of_graph_get_remote_port_parent(node);
+ of_node_put(node);
+ if (!ssd->asd.match.of.node) {
+ dev_warn(dev, "bad remote port parent\n");
+ return -EINVAL;
+ }
+
+ ssd->asd.match_type = V4L2_ASYNC_MATCH_OF;
+ notifier->num_subdevs++;
+ }
+
+ return notifier->num_subdevs;
+}
+
+static int vbs_registered(struct v4l2_subdev *sd)
+{
+ struct v4l2_device *v4l2_dev = sd->v4l2_dev;
+ struct vbs_data *pdata;
+ int err;
+
+ dev_dbg(sd->dev, "registered, init notifier...\n");
+
+ pdata = v4l2_get_subdevdata(sd);
+
+ err = v4l2_async_notifier_register(v4l2_dev, &pdata->notifier);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+static struct v4l2_subdev *vbs_get_remote_subdev(struct v4l2_subdev *sd)
+{
+ struct vbs_data *pdata = v4l2_get_subdevdata(sd);
+ struct media_entity *src;
+
+ if (pdata->state == CSI_SWITCH_DISABLED)
+ return ERR_PTR(-ENXIO);
+
+ src = pdata->src_pads[pdata->state].src;
+
+ return media_entity_to_v4l2_subdev(src);
+}
+
+static int vbs_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 vbs_data *pdata = v4l2_get_subdevdata(sd);
+ bool enable = flags & MEDIA_LNK_FL_ENABLED;
+
+ if (local->index > CSI_SWITCH_PORTS - 1)
+ return -ENXIO;
+
+ /* no configuration needed on source port */
+ if (local->index == 0)
+ return 0;
+
+ if (!enable) {
+ if (local->index == pdata->state) {
+ pdata->state = CSI_SWITCH_DISABLED;
+
+ /* Make sure we have both cameras enabled */
+ gpiod_set_value(pdata->swgpio, 1);
+ return 0;
+ } else {
+ return -EINVAL;
+ }
+ }
+
+ /* there can only be one active sink at the same time */
+ if (pdata->state != CSI_SWITCH_DISABLED)
+ return -EBUSY;
+
+ gpiod_set_value(pdata->swgpio, local->index == CSI_SWITCH_PORT_2);
+ pdata->state = local->index;
+
+ sd = vbs_get_remote_subdev(sd);
+ if (IS_ERR(sd))
+ return PTR_ERR(sd);
+
+ pdata->subdev.ctrl_handler = sd->ctrl_handler;
+
+ return 0;
+}
+
+static int vbs_subdev_notifier_bound(struct v4l2_async_notifier *async,
+ struct v4l2_subdev *subdev,
+ struct v4l2_async_subdev *asd)
+{
+ struct vbs_data *pdata = container_of(async,
+ struct vbs_data, notifier);
+ struct vbs_async_subdev *ssd =
+ container_of(asd, struct vbs_async_subdev, asd);
+ struct media_entity *sink = &pdata->subdev.entity;
+ struct media_entity *src = &subdev->entity;
+ int sink_pad = ssd->port;
+ int src_pad;
+
+ if (sink_pad >= sink->num_pads) {
+ dev_err(pdata->subdev.dev, "no sink pad in internal entity!\n");
+ return -EINVAL;
+ }
+
+ for (src_pad = 0; src_pad < subdev->entity.num_pads; src_pad++) {
+ if (subdev->entity.pads[src_pad].flags & MEDIA_PAD_FL_SOURCE)
+ break;
+ }
+
+ if (src_pad >= src->num_pads) {
+ dev_err(pdata->subdev.dev, "no source pad in external entity\n");
+ return -EINVAL;
+ }
+
+ pdata->src_pads[sink_pad].src = src;
+ pdata->src_pads[sink_pad].src_pad = src_pad;
+ ssd->sd = subdev;
+
+ return 0;
+}
+
+static int vbs_subdev_notifier_complete(struct v4l2_async_notifier *async)
+{
+ struct vbs_data *pdata = container_of(async, struct vbs_data, notifier);
+ struct media_entity *sink = &pdata->subdev.entity;
+ int sink_pad;
+
+ for (sink_pad = 1; sink_pad < CSI_SWITCH_PORTS; sink_pad++) {
+ struct media_entity *src = pdata->src_pads[sink_pad].src;
+ int src_pad = pdata->src_pads[sink_pad].src_pad;
+ int err;
+
+ err = media_create_pad_link(src, src_pad, sink, sink_pad, 0);
+ if (err < 0)
+ return err;
+
+ dev_dbg(pdata->subdev.dev, "create link: %s[%d] -> %s[%d])\n",
+ src->name, src_pad, sink->name, sink_pad);
+ }
+
+ return v4l2_device_register_subdev_nodes(pdata->subdev.v4l2_dev);
+}
+
+static int vbs_s_stream(struct v4l2_subdev *sd, int enable)
+{
+ struct v4l2_subdev *subdev = vbs_get_remote_subdev(sd);
+
+ if (IS_ERR(subdev))
+ return PTR_ERR(subdev);
+
+ return v4l2_subdev_call(subdev, video, s_stream, enable);
+}
+
+static const struct v4l2_subdev_internal_ops vbs_internal_ops = {
+ .registered = &vbs_registered,
+};
+
+static const struct media_entity_operations vbs_media_ops = {
+ .link_setup = vbs_link_setup,
+ .link_validate = v4l2_subdev_link_validate,
+};
+
+/* subdev video operations */
+static const struct v4l2_subdev_video_ops vbs_video_ops = {
+ .s_stream = vbs_s_stream,
+};
+
+static const struct v4l2_subdev_ops vbs_ops = {
+ .video = &vbs_video_ops,
+};
+
+static int video_bus_switch_probe(struct platform_device *pdev)
+{
+ struct vbs_data *pdata;
+ int err = 0;
+
+ /* platform data */
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ printk("video-bus-switch: not enough memory\n");
+ return -ENOMEM;
+ }
+ platform_set_drvdata(pdev, pdata);
+
+ /* switch gpio */
+ pdata->swgpio = devm_gpiod_get(&pdev->dev, "switch", GPIOD_OUT_HIGH);
+ if (IS_ERR(pdata->swgpio)) {
+ err = PTR_ERR(pdata->swgpio);
+ dev_err(&pdev->dev, "Failed to request gpio: %d\n", err);
+ return err;
+ }
+
+ /* find sub-devices */
+ err = vbs_of_parse_nodes(&pdev->dev, pdata);
+ if (err < 0) {
+ dev_err(&pdev->dev, "Failed to parse nodes: %d\n", err);
+ return err;
+ }
+
+ pdata->state = CSI_SWITCH_DISABLED;
+ pdata->notifier.bound = vbs_subdev_notifier_bound;
+ pdata->notifier.complete = vbs_subdev_notifier_complete;
+
+ /* setup subdev */
+ pdata->pads[0].flags = MEDIA_PAD_FL_SOURCE;
+ pdata->pads[1].flags = MEDIA_PAD_FL_SINK;
+ pdata->pads[2].flags = MEDIA_PAD_FL_SINK;
+
+ v4l2_subdev_init(&pdata->subdev, &vbs_ops);
+ pdata->subdev.dev = &pdev->dev;
+ pdata->subdev.owner = pdev->dev.driver->owner;
+ strncpy(pdata->subdev.name, dev_name(&pdev->dev), V4L2_SUBDEV_NAME_SIZE);
+ v4l2_set_subdevdata(&pdata->subdev, pdata);
+ pdata->subdev.entity.function = MEDIA_ENT_F_SWITCH;
+ pdata->subdev.entity.flags |= MEDIA_ENT_F_SWITCH;
+ pdata->subdev.entity.ops = &vbs_media_ops;
+ pdata->subdev.internal_ops = &vbs_internal_ops;
+ err = media_entity_pads_init(&pdata->subdev.entity, CSI_SWITCH_PORTS,
+ pdata->pads);
+ if (err < 0) {
+ dev_err(&pdev->dev, "Failed to init media entity: %d\n", err);
+ return err;
+ }
+
+ /* register subdev */
+ err = v4l2_async_register_subdev(&pdata->subdev);
+ if (err < 0) {
+ dev_err(&pdev->dev, "Failed to register v4l2 subdev: %d\n", err);
+ media_entity_cleanup(&pdata->subdev.entity);
+ return err;
+ }
+
+ dev_info(&pdev->dev, "video-bus-switch registered\n");
+
+ return 0;
+}
+
+static int video_bus_switch_remove(struct platform_device *pdev)
+{
+ struct vbs_data *pdata = platform_get_drvdata(pdev);
+
+ v4l2_async_notifier_unregister(&pdata->notifier);
+ v4l2_async_unregister_subdev(&pdata->subdev);
+ media_entity_cleanup(&pdata->subdev.entity);
+
+ return 0;
+}
+
+static const struct of_device_id video_bus_switch_of_match[] = {
+ { .compatible = "video-bus-switch" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, video_bus_switch_of_match);
+
+static struct platform_driver video_bus_switch_driver = {
+ .driver = {
+ .name = "video-bus-switch",
+ .of_match_table = video_bus_switch_of_match,
+ },
+ .probe = video_bus_switch_probe,
+ .remove = video_bus_switch_remove,
+};
+
+module_platform_driver(video_bus_switch_driver);
+
+MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
+MODULE_DESCRIPTION("Video Bus Switch");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:video-bus-switch");

--
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