[PATCH] media: Add video bus switch

From: Pavel Machek
Date: Sat Dec 24 2016 - 10:20:42 EST



N900 contains front and back camera, with a switch between the
two. This adds support for the switch component, and it is now
possible to select between front and back cameras during runtime.

Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
Signed-off-by: Pavel Machek <pavel@xxxxxx>


diff --git a/Documentation/devicetree/bindings/media/video-bus-switch.txt b/Documentation/devicetree/bindings/media/video-bus-switch.txt
new file mode 100644
index 0000000..1b9f8e0
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/video-bus-switch.txt
@@ -0,0 +1,63 @@
+Video Bus Switch Binding
+========================
+
+This is a binding for a gpio controlled switch for camera interfaces. Such a
+device is used on some embedded devices to connect two cameras to the same
+interface of a image signal processor.
+
+Required properties
+===================
+
+compatible : must contain "video-bus-switch"
+switch-gpios : GPIO specifier for the gpio, which can toggle the
+ selected camera. The GPIO should be configured, so
+ that a disabled GPIO means, that the first port is
+ selected.
+
+Required Port nodes
+===================
+
+More documentation on these bindings is available in
+video-interfaces.txt in the same directory.
+
+reg : The interface:
+ 0 - port for image signal processor
+ 1 - port for first camera sensor
+ 2 - port for second camera sensor
+
+Example
+=======
+
+video-bus-switch {
+ compatible = "video-bus-switch"
+ switch-gpios = <&gpio1 1 GPIO_ACTIVE_HIGH>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ csi_switch_in: endpoint {
+ remote-endpoint = <&csi_isp>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ csi_switch_out1: endpoint {
+ remote-endpoint = <&csi_cam1>;
+ };
+ };
+
+ port@2 {
+ reg = <2>;
+
+ csi_switch_out2: endpoint {
+ remote-endpoint = <&csi_cam2>;
+ };
+ };
+ };
+};
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index ce4a96f..a4b509e 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 && HAS_DMA
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 40b18d1..8eafc27 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..6400cfc
--- /dev/null
+++ b/drivers/media/platform/video-bus-switch.c
@@ -0,0 +1,387 @@
+/*
+ * Generic driver for video bus switches
+ *
+ * Copyright (C) 2015 Sebastian Reichel <sre@xxxxxxxxxx>
+ * Copyright (C) 2016 Pavel Machek <pavel@xxxxxx>
+ *
+ * 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 = 0,
+ CSI_SWITCH_PORT_1 = 1,
+ CSI_SWITCH_PORT_2 = 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];
+ struct v4l2_of_endpoint vep[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;
+ pdata->vep[notifier->num_subdevs] = vep;
+ 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;
+
+ dev_dbg(sd->dev, "Link setup: going to config %d\n", local->index);
+
+ 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 int vbs_g_endpoint_config(struct v4l2_subdev *sd, struct v4l2_of_endpoint *cfg)
+{
+ struct vbs_data *pdata = v4l2_get_subdevdata(sd);
+ dev_dbg(sd->dev, "vbs_g_endpoint_config... active port is %d\n", pdata->state);
+ *cfg = pdata->vep[pdata->state - 1];
+
+ return 0;
+}
+
+
+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,
+ .g_endpoint_config = vbs_g_endpoint_config,
+};
+
+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) {
+ dev_dbg(&pdev->dev, "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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Video Bus Switch");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:video-bus-switch");
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index cf778c5..448dbb5 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -25,6 +25,7 @@
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-mediabus.h>
+#include <media/v4l2-of.h>

/* generic v4l2_device notify callback notification values */
#define V4L2_SUBDEV_IR_RX_NOTIFY _IOW('v', 0, u32)
@@ -415,6 +416,8 @@ struct v4l2_subdev_video_ops {
const struct v4l2_mbus_config *cfg);
int (*s_rx_buffer)(struct v4l2_subdev *sd, void *buf,
unsigned int *size);
+ int (*g_endpoint_config)(struct v4l2_subdev *sd,
+ struct v4l2_of_endpoint *cfg);
};

/**
diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h
index 4890787..94648ab 100644
--- a/include/uapi/linux/media.h
+++ b/include/uapi/linux/media.h
@@ -147,6 +147,7 @@ struct media_device_info {
* MEDIA_ENT_F_IF_VID_DECODER and/or MEDIA_ENT_F_IF_AUD_DECODER.
*/
#define MEDIA_ENT_F_TUNER (MEDIA_ENT_F_OLD_SUBDEV_BASE + 5)
+#define MEDIA_ENT_F_SWITCH (MEDIA_ENT_F_OLD_SUBDEV_BASE + 6)

#define MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN MEDIA_ENT_F_OLD_SUBDEV_BASE



--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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