[RFC 09/13] media: Add video bus switch

From: Pavel Machek
Date: Tue Feb 14 2017 - 08:41:39 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.

FIXME: need to get acks and merge device tree support.

Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
Signed-off-by: Pavel Machek <pavel@xxxxxx>
---
.config | 1 +
drivers/media/platform/Kconfig | 10 +
drivers/media/platform/Makefile | 2 +
drivers/media/platform/omap3isp/ispccp2.c | 23 +-
drivers/media/platform/video-bus-switch.c | 389 ++++++++++++++++++++++++++++++
include/media/v4l2-subdev.h | 9 +-
include/uapi/linux/media.h | 2 +
7 files changed, 432 insertions(+), 4 deletions(-)
create mode 100644 drivers/media/platform/video-bus-switch.c

diff --git a/.config b/.config
index 611fdb8..0f2bdd8 100644
--- a/.config
+++ b/.config
@@ -2128,6 +2128,7 @@ CONFIG_V4L_PLATFORM_DRIVERS=y
# CONFIG_VIDEO_OMAP2_VOUT is not set
CONFIG_VIDEO_OMAP3=y
# CONFIG_VIDEO_OMAP3_DEBUG is not set
+CONFIG_VIDEO_BUS_SWITCH=y
# CONFIG_SOC_CAMERA is not set
# CONFIG_VIDEO_XILINX is not set
# CONFIG_V4L_MEM2MEM_DRIVERS is not set
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index c9106e1..b35f11b 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 349ddf6..6981319 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/omap3isp/ispccp2.c b/drivers/media/platform/omap3isp/ispccp2.c
index 4edb55a..c2bc6b7 100644
--- a/drivers/media/platform/omap3isp/ispccp2.c
+++ b/drivers/media/platform/omap3isp/ispccp2.c
@@ -171,7 +171,7 @@ static int ccp2_if_enable(struct isp_ccp2_device *ccp2, u8 enable)

pad = media_entity_remote_pad(&ccp2->pads[CCP2_PAD_SINK]);
sensor = media_entity_to_v4l2_subdev(pad->entity);
- /* Struct isp_bus_cfg has union inside */
+ /* Struct isp_bus_cfg has union inside */
buscfg = &((struct isp_bus_cfg *)sensor->host_priv)->bus.ccp2;


@@ -383,7 +383,7 @@ void __isp_of_parse_node_csi1(struct device *dev,
*/
static int ccp2_if_configure(struct isp_ccp2_device *ccp2)
{
- const struct isp_bus_cfg *buscfg;
+ struct isp_bus_cfg *buscfg;
struct v4l2_mbus_framefmt *format;
struct media_pad *pad;
struct v4l2_subdev *sensor;
@@ -396,6 +396,25 @@ static int ccp2_if_configure(struct isp_ccp2_device *ccp2)
sensor = media_entity_to_v4l2_subdev(pad->entity);
buscfg = sensor->host_priv;

+ {
+ struct v4l2_subdev *subdev2;
+ struct v4l2_of_endpoint vep;
+
+ subdev2 = media_entity_to_v4l2_subdev(pad->entity);
+
+ printk("if_configure... subdev %p\n", subdev2);
+ /* fixme: vep.base.port is wrong? */
+ ret = v4l2_subdev_call(subdev2, video, g_endpoint_config, &vep);
+ printk("if_configure ret %d\n", ret);
+ if (ret == 0) {
+ struct isp_ccp2_cfg prev_cfg = buscfg->bus.ccp2;
+ printk("Success: have configuration\n");
+ printk("Compare: %d\n", memcmp(&prev_cfg, &buscfg->bus.ccp2, sizeof(prev_cfg)));
+ __isp_of_parse_node_csi1(NULL, &buscfg->bus.ccp2, &vep);
+ printk("Configured ok?\n");
+ }
+ }
+
ret = ccp2_phyif_config(ccp2, &buscfg->bus.ccp2);
if (ret < 0)
return ret;
diff --git a/drivers/media/platform/video-bus-switch.c b/drivers/media/platform/video-bus-switch.c
new file mode 100644
index 0000000..1de611d
--- /dev/null
+++ b/drivers/media/platform/video-bus-switch.c
@@ -0,0 +1,389 @@
+/*
+ * 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 // FIXME: remove
+
+#include <linux/gpio/consumer.h>
+#include <linux/module.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-of.h>
+
+/*
+ * TODO:
+ * isp_subdev_notifier_complete() calls v4l2_device_register_subdev_nodes()
+ */
+
+enum vbs_state {
+ VBS_DISABLED = 0,
+ VBS_PORT_1 = 1,
+ VBS_PORT_2 = 2,
+ VBS_PORTS = 3,
+};
+
+#define VBS_SUBDEVS (VBS_PORTS - 1)
+
+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[VBS_PORTS];
+ struct vbs_src_pads src_pads[VBS_PORTS];
+ struct v4l2_of_endpoint vep[VBS_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, VBS_SUBDEVS,
+ sizeof(*notifier->subdevs), GFP_KERNEL);
+ if (!notifier->subdevs)
+ return -ENOMEM;
+
+ notifier->num_subdevs = 0;
+ while (notifier->num_subdevs < VBS_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;
+
+ pdata = v4l2_get_subdevdata(sd);
+
+ return v4l2_async_notifier_register(v4l2_dev, &pdata->notifier);
+}
+
+static void vbs_unregistered(struct v4l2_subdev *sd)
+{
+ struct v4l2_device *v4l2_dev = sd->v4l2_dev;
+ struct vbs_data *pdata;
+
+ pdata = v4l2_get_subdevdata(sd);
+
+ v4l2_async_notifier_unregister(&pdata->notifier);
+}
+
+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 == VBS_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 > VBS_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 = VBS_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 != VBS_DISABLED)
+ return -EBUSY;
+
+ dev_dbg(sd->dev, "Link setup: going to config %d\n", local->index);
+
+ gpiod_set_value(pdata->swgpio, local->index == VBS_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 < VBS_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);
+ }
+
+ /* FIXME: current ISP code may have problem with that */
+ 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,
+ .unregistered = &vbs_unregistered,
+};
+
+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 = VBS_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), sizeof(pdata->subdev.name));
+ v4l2_set_subdevdata(&pdata->subdev, pdata);
+ pdata->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_SWITCH;
+ pdata->subdev.entity.ops = &vbs_media_ops;
+ pdata->subdev.internal_ops = &vbs_internal_ops;
+ err = media_entity_pads_init(&pdata->subdev.entity, VBS_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_dbg(&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_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-gpio" },
+ { },
+};
+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 0ab1c5d..c6bb5fd 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)
@@ -351,7 +352,7 @@ struct v4l2_mbus_frame_desc {
* OUTPUT device. This is ignored by video capture devices.
*
* @g_input_status: get input status. Same as the status field in the
- * &struct &v4l2_input
+ * &struct &v4l2_input.
*
* @s_stream: used to notify the driver that a video stream will start or has
* stopped.
@@ -374,7 +375,7 @@ struct v4l2_mbus_frame_desc {
*
* @query_dv_timings: callback for %VIDIOC_QUERY_DV_TIMINGS ioctl handler code.
*
- * @g_mbus_config: get supported mediabus configurations
+ * @g_mbus_config: get supported mediabus configurations.
*
* @s_mbus_config: set a certain mediabus configuration. This operation is added
* for compatibility with soc-camera drivers and should not be used by new
@@ -383,6 +384,8 @@ struct v4l2_mbus_frame_desc {
* @s_rx_buffer: set a host allocated memory buffer for the subdev. The subdev
* can adjust @size to a lower value and must not write more data to the
* buffer starting at @data than the original value of @size.
+ *
+ * @g_endpoint_config: get link configuration required by this device.
*/
struct v4l2_subdev_video_ops {
int (*s_routing)(struct v4l2_subdev *sd, u32 input, u32 output, u32 config);
@@ -415,6 +418,8 @@ 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..a250456 100644
--- a/include/uapi/linux/media.h
+++ b/include/uapi/linux/media.h
@@ -103,6 +103,7 @@ struct media_device_info {
#define MEDIA_ENT_F_PROC_VIDEO_LUT (MEDIA_ENT_F_BASE + 0x4004)
#define MEDIA_ENT_F_PROC_VIDEO_SCALER (MEDIA_ENT_F_BASE + 0x4005)
#define MEDIA_ENT_F_PROC_VIDEO_STATISTICS (MEDIA_ENT_F_BASE + 0x4006)
+#define MEDIA_ENT_F_PROC_VIDEO_SWITCH (MEDIA_ENT_F_BASE + 0x4007)

/*
* Connectors
@@ -148,6 +149,7 @@ struct media_device_info {
*/
#define MEDIA_ENT_F_TUNER (MEDIA_ENT_F_OLD_SUBDEV_BASE + 5)

+
#define MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN MEDIA_ENT_F_OLD_SUBDEV_BASE

#if !defined(__KERNEL__) || defined(__NEED_MEDIA_LEGACY_API)
--
2.1.4


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

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