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Subject[PATCH v3 13/24] platform: add video-multiplexer subdevice driver
Date
From: Philipp Zabel <p.zabel@pengutronix.de>

This driver can handle SoC internal and external video bus multiplexers,
controlled either by register bit fields or by a GPIO. The subdevice
passes through frame interval and mbus configuration of the active input
to the output side.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

--

- fixed a cut&paste error in vidsw_remove(): v4l2_async_register_subdev()
should be unregister.

- added media_entity_cleanup() and v4l2_device_unregister_subdev()
to vidsw_remove().

- there was a line left over from a previous iteration that negated
the new way of determining the pad count just before it which
has been removed (num_pads = of_get_child_count(np)).

- Philipp Zabel has developed a set of patches that allow adding
to the subdev async notifier waiting list using a chaining method
from the async registered callbacks (v4l2_of_subdev_registered()
and the prep patches for that). For now, I've removed the use of
v4l2_of_subdev_registered() for the vidmux driver's registered
callback. This doesn't affect the functionality of this driver,
but allows for it to be merged now, before adding the chaining
support.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
---
.../bindings/media/video-multiplexer.txt | 59 +++
drivers/media/platform/Kconfig | 8 +
drivers/media/platform/Makefile | 2 +
drivers/media/platform/video-multiplexer.c | 472 +++++++++++++++++++++
4 files changed, 541 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/video-multiplexer.txt
create mode 100644 drivers/media/platform/video-multiplexer.c

diff --git a/Documentation/devicetree/bindings/media/video-multiplexer.txt b/Documentation/devicetree/bindings/media/video-multiplexer.txt
new file mode 100644
index 0000000..9d133d9
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/video-multiplexer.txt
@@ -0,0 +1,59 @@
+Video Multiplexer
+=================
+
+Video multiplexers allow to select between multiple input ports. Video received
+on the active input port is passed through to the output port. Muxes described
+by this binding may be controlled by a syscon register bitfield or by a GPIO.
+
+Required properties:
+- compatible : should be "video-multiplexer"
+- reg: should be register base of the register containing the control bitfield
+- bit-mask: bitmask of the control bitfield in the control register
+- bit-shift: bit offset of the control bitfield in the control register
+- gpios: alternatively to reg, bit-mask, and bit-shift, a single GPIO phandle
+ may be given to switch between two inputs
+- #address-cells: should be <1>
+- #size-cells: should be <0>
+- port@*: at least three port nodes containing endpoints connecting to the
+ source and sink devices according to of_graph bindings. The last port is
+ the output port, all others are inputs.
+
+Example:
+
+syscon {
+ compatible = "syscon", "simple-mfd";
+
+ mux {
+ compatible = "video-multiplexer";
+ /* Single bit (1 << 19) in syscon register 0x04: */
+ reg = <0x04>;
+ bit-mask = <1>;
+ bit-shift = <19>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ mux_in0: endpoint {
+ remote-endpoint = <&video_source0_out>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ mux_in1: endpoint {
+ remote-endpoint = <&video_source1_out>;
+ };
+ };
+
+ port@2 {
+ reg = <2>;
+
+ mux_out: endpoint {
+ remote-endpoint = <&capture_interface_in>;
+ };
+ };
+ };
+};
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index d944421..65614b5 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -74,6 +74,14 @@ config VIDEO_M32R_AR_M64278
To compile this driver as a module, choose M here: the
module will be called arv.

+config VIDEO_MULTIPLEXER
+ tristate "Video Multiplexer"
+ depends on VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER
+ help
+ This driver provides support for SoC internal N:1 video bus
+ multiplexers controlled by register bitfields as well as external
+ 2:1 video multiplexers controlled by a single GPIO.
+
config VIDEO_OMAP3
tristate "OMAP 3 Camera support"
depends on VIDEO_V4L2 && I2C && VIDEO_V4L2_SUBDEV_API && ARCH_OMAP3
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 5b3cb27..7cf0ee5 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -27,6 +27,8 @@ obj-$(CONFIG_VIDEO_SH_VEU) += sh_veu.o

obj-$(CONFIG_VIDEO_MEM2MEM_DEINTERLACE) += m2m-deinterlace.o

+obj-$(CONFIG_VIDEO_MULTIPLEXER) += video-multiplexer.o
+
obj-$(CONFIG_VIDEO_S3C_CAMIF) += s3c-camif/
obj-$(CONFIG_VIDEO_SAMSUNG_EXYNOS4_IS) += exynos4-is/
obj-$(CONFIG_VIDEO_SAMSUNG_S5P_JPEG) += s5p-jpeg/
diff --git a/drivers/media/platform/video-multiplexer.c b/drivers/media/platform/video-multiplexer.c
new file mode 100644
index 0000000..48980c4
--- /dev/null
+++ b/drivers/media/platform/video-multiplexer.c
@@ -0,0 +1,472 @@
+/*
+ * video stream multiplexer controlled via gpio or syscon
+ *
+ * Copyright (C) 2013 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
+ * Copyright (C) 2016 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/gpio/consumer.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+#include <media/v4l2-of.h>
+
+struct vidsw {
+ struct v4l2_subdev subdev;
+ unsigned int num_pads;
+ struct media_pad *pads;
+ struct v4l2_mbus_framefmt *format_mbus;
+ struct v4l2_fract timeperframe;
+ struct v4l2_of_endpoint *endpoint;
+ struct regmap_field *field;
+ struct gpio_desc *gpio;
+ int active;
+};
+
+static inline struct vidsw *v4l2_subdev_to_vidsw(struct v4l2_subdev *sd)
+{
+ return container_of(sd, struct vidsw, subdev);
+}
+
+static void vidsw_set_active(struct vidsw *vidsw, int active)
+{
+ vidsw->active = active;
+ if (active < 0)
+ return;
+
+ dev_dbg(vidsw->subdev.dev, "setting %d active\n", active);
+
+ if (vidsw->field)
+ regmap_field_write(vidsw->field, active);
+ else if (vidsw->gpio)
+ gpiod_set_value(vidsw->gpio, active);
+}
+
+static int vidsw_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 vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+
+ /* We have no limitations on enabling or disabling our output link */
+ if (local->index == vidsw->num_pads - 1)
+ return 0;
+
+ dev_dbg(sd->dev, "link setup %s -> %s", remote->entity->name,
+ local->entity->name);
+
+ if (!(flags & MEDIA_LNK_FL_ENABLED)) {
+ if (local->index == vidsw->active) {
+ dev_dbg(sd->dev, "going inactive\n");
+ vidsw->active = -1;
+ }
+ return 0;
+ }
+
+ if (vidsw->active >= 0) {
+ struct media_pad *pad;
+
+ if (vidsw->active == local->index)
+ return 0;
+
+ pad = media_entity_remote_pad(&vidsw->pads[vidsw->active]);
+ if (pad) {
+ struct media_link *link;
+ int ret;
+
+ link = media_entity_find_link(pad,
+ &vidsw->pads[vidsw->active]);
+ if (link) {
+ ret = __media_entity_setup_link(link, 0);
+ if (ret)
+ return ret;
+ }
+ }
+ }
+
+ vidsw_set_active(vidsw, local->index);
+
+ return 0;
+}
+
+static struct media_entity_operations vidsw_ops = {
+ .link_setup = vidsw_link_setup,
+};
+
+static bool vidsw_endpoint_disabled(struct device_node *ep)
+{
+ struct device_node *rpp;
+
+ if (!of_device_is_available(ep))
+ return true;
+
+ rpp = of_graph_get_remote_port_parent(ep);
+ if (!rpp)
+ return true;
+
+ return !of_device_is_available(rpp);
+}
+
+static int vidsw_async_init(struct vidsw *vidsw, struct device_node *node)
+{
+ struct device_node *ep;
+ u32 portno;
+ int numports;
+ int ret;
+ int i;
+ bool active_link = false;
+
+ numports = vidsw->num_pads;
+
+ for (i = 0; i < numports - 1; i++)
+ vidsw->pads[i].flags = MEDIA_PAD_FL_SINK;
+ vidsw->pads[numports - 1].flags = MEDIA_PAD_FL_SOURCE;
+
+ vidsw->subdev.entity.function = MEDIA_ENT_F_MUX;
+ ret = media_entity_pads_init(&vidsw->subdev.entity, numports,
+ vidsw->pads);
+ if (ret < 0)
+ return ret;
+
+ vidsw->subdev.entity.ops = &vidsw_ops;
+
+ for_each_endpoint_of_node(node, ep) {
+ struct v4l2_of_endpoint endpoint;
+
+ v4l2_of_parse_endpoint(ep, &endpoint);
+
+ portno = endpoint.base.port;
+ if (portno >= numports - 1)
+ continue;
+
+ if (vidsw_endpoint_disabled(ep)) {
+ dev_dbg(vidsw->subdev.dev, "port %d disabled\n", portno);
+ continue;
+ }
+
+ vidsw->endpoint[portno] = endpoint;
+
+ if (portno == vidsw->active)
+ active_link = true;
+ }
+
+ for (portno = 0; portno < numports - 1; portno++) {
+ if (!vidsw->endpoint[portno].base.local_node)
+ continue;
+
+ /* If the active input is not connected, use another */
+ if (!active_link) {
+ vidsw_set_active(vidsw, portno);
+ active_link = true;
+ }
+ }
+
+ return v4l2_async_register_subdev(&vidsw->subdev);
+}
+
+int vidsw_g_mbus_config(struct v4l2_subdev *sd, struct v4l2_mbus_config *cfg)
+{
+ struct vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+ struct media_pad *pad;
+ int ret;
+
+ if (vidsw->active == -1) {
+ dev_err(sd->dev, "no configuration for inactive mux\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Retrieve media bus configuration from the entity connected to the
+ * active input
+ */
+ pad = media_entity_remote_pad(&vidsw->pads[vidsw->active]);
+ if (pad) {
+ sd = media_entity_to_v4l2_subdev(pad->entity);
+ ret = v4l2_subdev_call(sd, video, g_mbus_config, cfg);
+ if (ret == -ENOIOCTLCMD)
+ pad = NULL;
+ else if (ret < 0) {
+ dev_err(sd->dev, "failed to get source configuration\n");
+ return ret;
+ }
+ }
+ if (!pad) {
+ /* Mirror the input side on the output side */
+ cfg->type = vidsw->endpoint[vidsw->active].bus_type;
+ if (cfg->type == V4L2_MBUS_PARALLEL ||
+ cfg->type == V4L2_MBUS_BT656)
+ cfg->flags = vidsw->endpoint[vidsw->active].bus.parallel.flags;
+ }
+
+ return 0;
+}
+
+static int vidsw_s_stream(struct v4l2_subdev *sd, int enable)
+{
+ struct vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+ struct v4l2_subdev *upstream_sd;
+ struct media_pad *pad;
+
+ if (vidsw->active == -1) {
+ dev_err(sd->dev, "Can not start streaming on inactive mux\n");
+ return -EINVAL;
+ }
+
+ pad = media_entity_remote_pad(&sd->entity.pads[vidsw->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 int vidsw_g_frame_interval(struct v4l2_subdev *sd,
+ struct v4l2_subdev_frame_interval *fi)
+{
+ struct vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+
+ fi->interval = vidsw->timeperframe;
+
+ return 0;
+}
+
+static int vidsw_s_frame_interval(struct v4l2_subdev *sd,
+ struct v4l2_subdev_frame_interval *fi)
+{
+ struct vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+
+ vidsw->timeperframe = fi->interval;
+
+ return 0;
+}
+
+static const struct v4l2_subdev_video_ops vidsw_subdev_video_ops = {
+ .g_mbus_config = vidsw_g_mbus_config,
+ .s_stream = vidsw_s_stream,
+ .g_frame_interval = vidsw_g_frame_interval,
+ .s_frame_interval = vidsw_s_frame_interval,
+};
+
+static struct v4l2_mbus_framefmt *
+__vidsw_get_pad_format(struct v4l2_subdev *sd,
+ struct v4l2_subdev_pad_config *cfg,
+ unsigned int pad, u32 which)
+{
+ struct vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+
+ switch (which) {
+ case V4L2_SUBDEV_FORMAT_TRY:
+ return v4l2_subdev_get_try_format(sd, cfg, pad);
+ case V4L2_SUBDEV_FORMAT_ACTIVE:
+ return &vidsw->format_mbus[pad];
+ default:
+ return NULL;
+ }
+}
+
+static int vidsw_get_format(struct v4l2_subdev *sd,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *sdformat)
+{
+ sdformat->format = *__vidsw_get_pad_format(sd, cfg, sdformat->pad,
+ sdformat->which);
+ return 0;
+}
+
+static int vidsw_set_format(struct v4l2_subdev *sd,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *sdformat)
+{
+ struct vidsw *vidsw = v4l2_subdev_to_vidsw(sd);
+ struct v4l2_mbus_framefmt *mbusformat;
+
+ if (sdformat->pad >= vidsw->num_pads)
+ return -EINVAL;
+
+ mbusformat = __vidsw_get_pad_format(sd, cfg, sdformat->pad,
+ sdformat->which);
+ if (!mbusformat)
+ return -EINVAL;
+
+ /* Output pad mirrors active input pad, no limitations on input pads */
+ if (sdformat->pad == (vidsw->num_pads - 1) && vidsw->active >= 0)
+ sdformat->format = vidsw->format_mbus[vidsw->active];
+
+ *mbusformat = sdformat->format;
+
+ return 0;
+}
+
+static struct v4l2_subdev_pad_ops vidsw_pad_ops = {
+ .get_fmt = vidsw_get_format,
+ .set_fmt = vidsw_set_format,
+};
+
+static struct v4l2_subdev_ops vidsw_subdev_ops = {
+ .pad = &vidsw_pad_ops,
+ .video = &vidsw_subdev_video_ops,
+};
+
+static int of_get_reg_field(struct device_node *node, struct reg_field *field)
+{
+ u32 bit_mask;
+ int ret;
+
+ ret = of_property_read_u32(node, "reg", &field->reg);
+ if (ret < 0)
+ return ret;
+
+ ret = of_property_read_u32(node, "bit-mask", &bit_mask);
+ if (ret < 0)
+ return ret;
+
+ ret = of_property_read_u32(node, "bit-shift", &field->lsb);
+ if (ret < 0)
+ return ret;
+
+ field->msb = field->lsb + fls(bit_mask) - 1;
+
+ return 0;
+}
+
+static int vidsw_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct of_endpoint endpoint;
+ struct device_node *ep;
+ struct reg_field field;
+ struct vidsw *vidsw;
+ struct regmap *map;
+ unsigned int num_pads;
+ int ret;
+
+ vidsw = devm_kzalloc(&pdev->dev, sizeof(*vidsw), GFP_KERNEL);
+ if (!vidsw)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, vidsw);
+
+ v4l2_subdev_init(&vidsw->subdev, &vidsw_subdev_ops);
+ snprintf(vidsw->subdev.name, sizeof(vidsw->subdev.name), "%s",
+ np->name);
+ vidsw->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+ vidsw->subdev.dev = &pdev->dev;
+
+ /*
+ * The largest numbered port is the output port. It determines
+ * total number of pads
+ */
+ num_pads = 0;
+ for_each_endpoint_of_node(np, ep) {
+ of_graph_parse_endpoint(ep, &endpoint);
+ num_pads = max(num_pads, endpoint.port + 1);
+ }
+
+ if (num_pads < 2) {
+ dev_err(&pdev->dev, "Not enough ports %d\n", num_pads);
+ return -EINVAL;
+ }
+
+ ret = of_get_reg_field(np, &field);
+ if (ret == 0) {
+ map = syscon_node_to_regmap(np->parent);
+ if (!map) {
+ dev_err(&pdev->dev, "Failed to get syscon register map\n");
+ return PTR_ERR(map);
+ }
+
+ vidsw->field = devm_regmap_field_alloc(&pdev->dev, map, field);
+ if (IS_ERR(vidsw->field)) {
+ dev_err(&pdev->dev, "Failed to allocate regmap field\n");
+ return PTR_ERR(vidsw->field);
+ }
+
+ regmap_field_read(vidsw->field, &vidsw->active);
+ } else {
+ if (num_pads > 3) {
+ dev_err(&pdev->dev, "Too many ports %d\n", num_pads);
+ return -EINVAL;
+ }
+
+ vidsw->gpio = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW);
+ if (IS_ERR(vidsw->gpio)) {
+ dev_warn(&pdev->dev,
+ "could not request control gpio: %d\n", ret);
+ vidsw->gpio = NULL;
+ }
+
+ vidsw->active = gpiod_get_value(vidsw->gpio) ? 1 : 0;
+ }
+
+ vidsw->num_pads = num_pads;
+ vidsw->pads = devm_kzalloc(&pdev->dev, sizeof(*vidsw->pads) * num_pads,
+ GFP_KERNEL);
+ vidsw->format_mbus = devm_kzalloc(&pdev->dev,
+ sizeof(*vidsw->format_mbus) * num_pads, GFP_KERNEL);
+ vidsw->endpoint = devm_kzalloc(&pdev->dev,
+ sizeof(*vidsw->endpoint) * (num_pads - 1), GFP_KERNEL);
+
+ ret = vidsw_async_init(vidsw, np);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int vidsw_remove(struct platform_device *pdev)
+{
+ struct vidsw *vidsw = platform_get_drvdata(pdev);
+ struct v4l2_subdev *sd = &vidsw->subdev;
+
+ v4l2_async_unregister_subdev(sd);
+ media_entity_cleanup(&sd->entity);
+ v4l2_device_unregister_subdev(sd);
+
+ return 0;
+}
+
+static const struct of_device_id vidsw_dt_ids[] = {
+ { .compatible = "video-multiplexer", },
+ { /* sentinel */ }
+};
+
+static struct platform_driver vidsw_driver = {
+ .probe = vidsw_probe,
+ .remove = vidsw_remove,
+ .driver = {
+ .of_match_table = vidsw_dt_ids,
+ .name = "video-multiplexer",
+ },
+};
+
+module_platform_driver(vidsw_driver);
+
+MODULE_DESCRIPTION("video stream multiplexer");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_AUTHOR("Philipp Zabel, Pengutronix");
+MODULE_LICENSE("GPL");
--
2.7.4
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