[PATCH v3 1/2] [media] dt-bindings: Add bindings for video-multiplexer device

[PATCH v3 1/2] [media] dt-bindings: Add bindings for video-multiplexer device

[Philipp Zabel]

Add bindings documentation for the video multiplexer device.

Signed-off-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Signed-off-by: Steve Longerbeam <steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
Acked-by: Peter Rosin <peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
Acked-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
No changes since v2 [1].

This was previously sent as part of Steve's i.MX media series [2].

[1] https://patchwork.kernel.org/patch/9708235/
[2] https://patchwork.kernel.org/patch/9647951/
---
 .../devicetree/bindings/media/video-mux.txt        | 60 ++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/video-mux.txt

diff --git a/Documentation/devicetree/bindings/media/video-mux.txt b/Documentation/devicetree/bindings/media/video-mux.txt
new file mode 100644
index 0000000000000..63b9dc913e456
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/video-mux.txt
@@ -0,0 +1,60 @@
+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 are controlled by a multiplexer controller that is described by
+the bindings in Documentation/devicetree/bindings/mux/mux-controller.txt
+
+Required properties:
+- compatible : should be "video-mux"
+- mux-controls : mux controller node to use for operating the mux
+- #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.
+
+Optionally, #address-cells, #size-cells, and port nodes can be grouped under a
+ports node as described in Documentation/devicetree/bindings/graph.txt.
+
+Example:
+
+	mux: mux-controller {
+		compatible = "gpio-mux";
+		#mux-control-cells = <0>;
+
+		mux-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
+	};
+
+	video-mux {
+		compatible = "video-mux";
+		mux-controls = <&mux>;
+		#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>;
+			};
+		};
+	};
+};
-- 
2.11.0

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[PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Philipp Zabel]

This driver can handle SoC internal and external video bus multiplexers,
controlled by mux controllers provided by the mux controller framework,
such as MMIO register bitfields or GPIOs. The subdevice passes through
the mbus configuration of the active input to the output side.

Signed-off-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Signed-off-by: Steve Longerbeam <steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
---
Changes since v2 [1]:
 - Extend vmux->lock to protect mbus format against simultaneous access
   from get/set_format calls.
 - Drop is_source_pad(), check pad->flags & MEDIA_PAD_FL_SOURCE directly.
 - Replace v4l2_of_parse_endpoint call with v4l2_fwnode_endpoint_parse,
   include media/v4l2-fwnode.h instead of media/v4l2-of.h.
 - Constify ops structures.

This was previously sent as part of Steve's i.MX media series [2].
Tested against
https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi-merge

[1] https://patchwork.kernel.org/patch/9708237/
[2] https://patchwork.kernel.org/patch/9647869/
---
 drivers/media/platform/Kconfig     |   6 +
 drivers/media/platform/Makefile    |   2 +
 drivers/media/platform/video-mux.c | 318 +++++++++++++++++++++++++++++++++++++
 3 files changed, 326 insertions(+)
 create mode 100644 drivers/media/platform/video-mux.c

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index 317f8d41e4ad6..2fea699962624 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -74,6 +74,12 @@ config VIDEO_M32R_AR_M64278
 	  To compile this driver as a module, choose M here: the
 	  module will be called arv.
 
+config VIDEO_MUX
+	tristate "Video Multiplexer"
+	depends on OF && VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER && MULTIPLEXER
+	help
+	  This driver provides support for N:1 video bus multiplexers.
+
 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 63303d63c64cf..a6363023f981e 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -28,6 +28,8 @@ obj-$(CONFIG_VIDEO_SH_VEU)		+= sh_veu.o
 
 obj-$(CONFIG_VIDEO_MEM2MEM_DEINTERLACE)	+= m2m-deinterlace.o
 
+obj-$(CONFIG_VIDEO_MUX)			+= video-mux.o
+
 obj-$(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-mux.c b/drivers/media/platform/video-mux.c
new file mode 100644
index 0000000000000..afa06febf6c33
--- /dev/null
+++ b/drivers/media/platform/video-mux.c
@@ -0,0 +1,318 @@
+/*
+ * video stream multiplexer controlled via mux control
+ *
+ * Copyright (C) 2013 Pengutronix, Sascha Hauer <kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
+ * Copyright (C) 2016-2017 Pengutronix, Philipp Zabel <kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
+ *
+ * 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/mux/consumer.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-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+struct video_mux {
+	struct v4l2_subdev subdev;
+	struct media_pad *pads;
+	struct v4l2_mbus_framefmt *format_mbus;
+	struct v4l2_fwnode_endpoint *endpoint;
+	struct mux_control *mux;
+	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 = mux_control_try_select(vmux->mux, 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");
+		mux_control_deselect(vmux->mux);
+		vmux->active = -1;
+	}
+
+out:
+	mutex_unlock(&vmux->lock);
+	return ret;
+}
+
+static struct media_entity_operations video_mux_ops = {
+	.link_setup = video_mux_link_setup,
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static bool video_mux_endpoint_disabled(struct device_node *ep)
+{
+	struct device_node *rpp = of_graph_get_remote_port_parent(ep);
+
+	return !of_device_is_available(rpp);
+}
+
+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(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;
+	}
+
+	vmux->mux = devm_mux_control_get(dev, NULL);
+	if (IS_ERR(vmux->mux)) {
+		ret = PTR_ERR(vmux->mux);
+		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_kzalloc(dev, sizeof(*vmux->pads) * num_pads,
+				  GFP_KERNEL);
+	vmux->format_mbus = devm_kzalloc(dev, sizeof(*vmux->format_mbus) *
+					 num_pads, GFP_KERNEL);
+	vmux->endpoint = devm_kzalloc(dev, sizeof(*vmux->endpoint) *
+				      (num_pads - 1), 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;
+
+	for_each_endpoint_of_node(np, ep) {
+		struct v4l2_fwnode_endpoint endpoint;
+
+		v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &endpoint);
+
+		if (video_mux_endpoint_disabled(ep)) {
+			dev_dbg(dev, "port %d disabled\n", endpoint.base.port);
+			continue;
+		}
+
+		vmux->endpoint[endpoint.base.port] = endpoint;
+	}
+
+	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");
-- 
2.11.0

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Re: [PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Kieran Bingham]

Hi Philipp,

Thankyou for the patch,

On 04/05/17 14:38, Philipp Zabel wrote:
> This driver can handle SoC internal and external video bus multiplexers,
> controlled by mux controllers provided by the mux controller framework,
> such as MMIO register bitfields or GPIOs. The subdevice passes through
> the 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>
> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
> ---
> Changes since v2 [1]:
>  - Extend vmux->lock to protect mbus format against simultaneous access
>    from get/set_format calls.
>  - Drop is_source_pad(), check pad->flags & MEDIA_PAD_FL_SOURCE directly.
>  - Replace v4l2_of_parse_endpoint call with v4l2_fwnode_endpoint_parse,
>    include media/v4l2-fwnode.h instead of media/v4l2-of.h.
>  - Constify ops structures.
> 
> This was previously sent as part of Steve's i.MX media series [2].
> Tested against
> https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi-merge
> 
> [1] https://patchwork.kernel.org/patch/9708237/
> [2] https://patchwork.kernel.org/patch/9647869/
> ---
>  drivers/media/platform/Kconfig     |   6 +
>  drivers/media/platform/Makefile    |   2 +
>  drivers/media/platform/video-mux.c | 318 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 326 insertions(+)
>  create mode 100644 drivers/media/platform/video-mux.c
> 
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index 317f8d41e4ad6..2fea699962624 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -74,6 +74,12 @@ config VIDEO_M32R_AR_M64278
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called arv.
>  
> +config VIDEO_MUX
> +	tristate "Video Multiplexer"
> +	depends on OF && VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER && MULTIPLEXER
> +	help
> +	  This driver provides support for N:1 video bus multiplexers.
> +
>  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 63303d63c64cf..a6363023f981e 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -28,6 +28,8 @@ obj-$(CONFIG_VIDEO_SH_VEU)		+= sh_veu.o
>  
>  obj-$(CONFIG_VIDEO_MEM2MEM_DEINTERLACE)	+= m2m-deinterlace.o
>  
> +obj-$(CONFIG_VIDEO_MUX)			+= video-mux.o
> +
>  obj-$(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-mux.c b/drivers/media/platform/video-mux.c
> new file mode 100644
> index 0000000000000..afa06febf6c33
> --- /dev/null
> +++ b/drivers/media/platform/video-mux.c
> @@ -0,0 +1,318 @@
> +/*
> + * 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/mux/consumer.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-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +
> +struct video_mux {
> +	struct v4l2_subdev subdev;
> +	struct media_pad *pads;
> +	struct v4l2_mbus_framefmt *format_mbus;
> +	struct v4l2_fwnode_endpoint *endpoint;
> +	struct mux_control *mux;
> +	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 = mux_control_try_select(vmux->mux, 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");
> +		mux_control_deselect(vmux->mux);
> +		vmux->active = -1;
> +	}
> +
> +out:
> +	mutex_unlock(&vmux->lock);
> +	return ret;
> +}
> +
> +static struct media_entity_operations video_mux_ops = {
> +	.link_setup = video_mux_link_setup,
> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
> +static bool video_mux_endpoint_disabled(struct device_node *ep)
> +{
> +	struct device_node *rpp = of_graph_get_remote_port_parent(ep);
> +
> +	return !of_device_is_available(rpp);
> +}
> +
> +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(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;
> +	}
> +
> +	vmux->mux = devm_mux_control_get(dev, NULL);
> +	if (IS_ERR(vmux->mux)) {
> +		ret = PTR_ERR(vmux->mux);
> +		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_kzalloc(dev, sizeof(*vmux->pads) * num_pads,
> +				  GFP_KERNEL);
> +	vmux->format_mbus = devm_kzalloc(dev, sizeof(*vmux->format_mbus) *
> +					 num_pads, GFP_KERNEL);
> +	vmux->endpoint = devm_kzalloc(dev, sizeof(*vmux->endpoint) *
> +				      (num_pads - 1), 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;
> +
> +	for_each_endpoint_of_node(np, ep) {
> +		struct v4l2_fwnode_endpoint endpoint;
> +
> +		v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &endpoint);
> +
> +		if (video_mux_endpoint_disabled(ep)) {
> +			dev_dbg(dev, "port %d disabled\n", endpoint.base.port);
> +			continue;
> +		}
> +
> +		vmux->endpoint[endpoint.base.port] = endpoint;

There is no verification here that endpoint.base.port is a valid value.
	( <= num_pads - 1 )

As it comes in from the DT, it 'could' be set as any arbitrary value. Should it
be sanity checked ? Or do we trust the DT at this point ?

> +	}
> +
> +	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");
> 

Re: [PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Philipp Zabel]

Hi Kieran,

On Thu, 2017-05-04 at 15:59 +0100, Kieran Bingham wrote:
> Hi Philipp,
> 
> Thankyou for the patch,

thank you for reviewing.

> On 04/05/17 14:38, Philipp Zabel wrote:
> > This driver can handle SoC internal and external video bus multiplexers,
> > controlled by mux controllers provided by the mux controller framework,
> > such as MMIO register bitfields or GPIOs. The subdevice passes through
> > the 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>
> > Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
> > ---
> > Changes since v2 [1]:
> >  - Extend vmux->lock to protect mbus format against simultaneous access
> >    from get/set_format calls.
> >  - Drop is_source_pad(), check pad->flags & MEDIA_PAD_FL_SOURCE directly.
> >  - Replace v4l2_of_parse_endpoint call with v4l2_fwnode_endpoint_parse,
> >    include media/v4l2-fwnode.h instead of media/v4l2-of.h.
> >  - Constify ops structures.
> > 
> > This was previously sent as part of Steve's i.MX media series [2].
> > Tested against
> > https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi-merge
> > 
> > [1] https://patchwork.kernel.org/patch/9708237/
> > [2] https://patchwork.kernel.org/patch/9647869/
> > ---
> >  drivers/media/platform/Kconfig     |   6 +
> >  drivers/media/platform/Makefile    |   2 +
> >  drivers/media/platform/video-mux.c | 318 +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 326 insertions(+)
> >  create mode 100644 drivers/media/platform/video-mux.c
> > 
> > diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> > index 317f8d41e4ad6..2fea699962624 100644
> > --- a/drivers/media/platform/Kconfig
> > +++ b/drivers/media/platform/Kconfig
> > @@ -74,6 +74,12 @@ config VIDEO_M32R_AR_M64278
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called arv.
> >  
> > +config VIDEO_MUX
> > +	tristate "Video Multiplexer"
> > +	depends on OF && VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER && MULTIPLEXER
> > +	help
> > +	  This driver provides support for N:1 video bus multiplexers.
> > +
> >  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 63303d63c64cf..a6363023f981e 100644
> > --- a/drivers/media/platform/Makefile
> > +++ b/drivers/media/platform/Makefile
> > @@ -28,6 +28,8 @@ obj-$(CONFIG_VIDEO_SH_VEU)		+= sh_veu.o
> >  
> >  obj-$(CONFIG_VIDEO_MEM2MEM_DEINTERLACE)	+= m2m-deinterlace.o
> >  
> > +obj-$(CONFIG_VIDEO_MUX)			+= video-mux.o
> > +
> >  obj-$(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-mux.c b/drivers/media/platform/video-mux.c
> > new file mode 100644
> > index 0000000000000..afa06febf6c33
> > --- /dev/null
> > +++ b/drivers/media/platform/video-mux.c
> > @@ -0,0 +1,318 @@
> > +/*
> > + * 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/mux/consumer.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-fwnode.h>
> > +#include <media/v4l2-subdev.h>
> > +
> > +struct video_mux {
> > +	struct v4l2_subdev subdev;
> > +	struct media_pad *pads;
> > +	struct v4l2_mbus_framefmt *format_mbus;
> > +	struct v4l2_fwnode_endpoint *endpoint;
> > +	struct mux_control *mux;
> > +	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 = mux_control_try_select(vmux->mux, 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");
> > +		mux_control_deselect(vmux->mux);
> > +		vmux->active = -1;
> > +	}
> > +
> > +out:
> > +	mutex_unlock(&vmux->lock);
> > +	return ret;
> > +}
> > +
> > +static struct media_entity_operations video_mux_ops = {
> > +	.link_setup = video_mux_link_setup,
> > +	.link_validate = v4l2_subdev_link_validate,
> > +};
> > +
> > +static bool video_mux_endpoint_disabled(struct device_node *ep)
> > +{
> > +	struct device_node *rpp = of_graph_get_remote_port_parent(ep);
> > +
> > +	return !of_device_is_available(rpp);
> > +}
> > +
> > +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(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;
> > +	}
> > +
> > +	vmux->mux = devm_mux_control_get(dev, NULL);
> > +	if (IS_ERR(vmux->mux)) {
> > +		ret = PTR_ERR(vmux->mux);
> > +		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_kzalloc(dev, sizeof(*vmux->pads) * num_pads,
> > +				  GFP_KERNEL);
> > +	vmux->format_mbus = devm_kzalloc(dev, sizeof(*vmux->format_mbus) *
> > +					 num_pads, GFP_KERNEL);
> > +	vmux->endpoint = devm_kzalloc(dev, sizeof(*vmux->endpoint) *
> > +				      (num_pads - 1), 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;
> > +
> > +	for_each_endpoint_of_node(np, ep) {
> > +		struct v4l2_fwnode_endpoint endpoint;
> > +
> > +		v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &endpoint);
> > +
> > +		if (video_mux_endpoint_disabled(ep)) {
> > +			dev_dbg(dev, "port %d disabled\n", endpoint.base.port);
> > +			continue;
> > +		}
> > +
> > +		vmux->endpoint[endpoint.base.port] = endpoint;
> 
> There is no verification here that endpoint.base.port is a valid value.
> 	( <= num_pads - 1 )

I just noticed that when changing to devm_kcalloc as Sebastian
suggested. I'll drop the endpoint parsing completely for now, as it
isn't even needed anymore with g_mbus_config gone.

> As it comes in from the DT, it 'could' be set as any arbitrary value.

Worse, we expect the output port (num_pads - 1) to exist and have a
valid link. But the vmux->endpoint array length is only num_pads - 1.
I have lost the sink port check at some point.

> Should it be sanity checked ? Or do we trust the DT at this point ?

Since this would avoid possible memory corruption, yes, it would be
better to check.

regards
Philipp

Re: [PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Sebastian Reichel]

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Hi,

On Thu, May 04, 2017 at 03:38:57PM +0200, Philipp Zabel wrote:
> This driver can handle SoC internal and external video bus multiplexers,
> controlled by mux controllers provided by the mux controller framework,
> such as MMIO register bitfields or GPIOs. The subdevice passes through
> the mbus configuration of the active input to the output side.
> 
> Signed-off-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Signed-off-by: Steve Longerbeam <steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
> ---
> Changes since v2 [1]:
>  - Extend vmux->lock to protect mbus format against simultaneous access
>    from get/set_format calls.
>  - Drop is_source_pad(), check pad->flags & MEDIA_PAD_FL_SOURCE directly.
>  - Replace v4l2_of_parse_endpoint call with v4l2_fwnode_endpoint_parse,
>    include media/v4l2-fwnode.h instead of media/v4l2-of.h.
>  - Constify ops structures.
> 
> This was previously sent as part of Steve's i.MX media series [2].
> Tested against
> https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi-merge
> 
> [1] https://patchwork.kernel.org/patch/9708237/
> [2] https://patchwork.kernel.org/patch/9647869/

Looks fine to me. Just one nitpick:

> +static int video_mux_probe(struct platform_device *pdev)
> +{

[...]

> +	vmux->pads = devm_kzalloc(dev, sizeof(*vmux->pads) * num_pads,
> +				  GFP_KERNEL);
> +	vmux->format_mbus = devm_kzalloc(dev, sizeof(*vmux->format_mbus) *
> +					 num_pads, GFP_KERNEL);
> +	vmux->endpoint = devm_kzalloc(dev, sizeof(*vmux->endpoint) *
> +				      (num_pads - 1), GFP_KERNEL);

devm_kcalloc(dev, num_pads, sizeof(*foo), GFP_KERNEL).

-- Sebastian

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Re: [PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Philipp Zabel]

Hi Sebastian,

On Thu, 2017-05-04 at 16:21 +0200, Sebastian Reichel wrote:
> Hi,
> 
> On Thu, May 04, 2017 at 03:38:57PM +0200, Philipp Zabel wrote:
> > This driver can handle SoC internal and external video bus multiplexers,
> > controlled by mux controllers provided by the mux controller framework,
> > such as MMIO register bitfields or GPIOs. The subdevice passes through
> > the 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>
> > Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
> > ---
> > Changes since v2 [1]:
> >  - Extend vmux->lock to protect mbus format against simultaneous access
> >    from get/set_format calls.
> >  - Drop is_source_pad(), check pad->flags & MEDIA_PAD_FL_SOURCE directly.
> >  - Replace v4l2_of_parse_endpoint call with v4l2_fwnode_endpoint_parse,
> >    include media/v4l2-fwnode.h instead of media/v4l2-of.h.
> >  - Constify ops structures.
> > 
> > This was previously sent as part of Steve's i.MX media series [2].
> > Tested against
> > https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi-merge
> > 
> > [1] https://patchwork.kernel.org/patch/9708237/
> > [2] https://patchwork.kernel.org/patch/9647869/
> 
> Looks fine to me. Just one nitpick:
> 
> > +static int video_mux_probe(struct platform_device *pdev)
> > +{
> 
> [...]
> 
> > +	vmux->pads = devm_kzalloc(dev, sizeof(*vmux->pads) * num_pads,
> > +				  GFP_KERNEL);
> > +	vmux->format_mbus = devm_kzalloc(dev, sizeof(*vmux->format_mbus) *
> > +					 num_pads, GFP_KERNEL);
> > +	vmux->endpoint = devm_kzalloc(dev, sizeof(*vmux->endpoint) *
> > +				      (num_pads - 1), GFP_KERNEL);
> 
> devm_kcalloc(dev, num_pads, sizeof(*foo), GFP_KERNEL).

thank you, I'll fix this.

regards
Philipp

Re: [PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Sakari Ailus]

Hi Philipp,

On Thu, May 04, 2017 at 03:38:57PM +0200, Philipp Zabel wrote:
...
> +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 = {

Shouldn't this be const?

With that,

Acked-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

> +	.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");

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus-X3B1VOXEql0@public.gmane.org	XMPP: sailus-PCDdDYkjdNMDXYZnReoRVg@public.gmane.org
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Re: [PATCH v3 2/2] [media] platform: add video-multiplexer subdevice driver

[Sakari Ailus]

On Thu, May 04, 2017 at 11:32:08PM +0300, Sakari Ailus wrote:
> Hi Philipp,
> 
> On Thu, May 04, 2017 at 03:38:57PM +0200, Philipp Zabel wrote:
> ...
> > +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 = {
> 
> Shouldn't this be const?

To reply myself --- no. Driver registration requires that, which makes
perfect sense. Please ignore the comment.

-- 
Sakari Ailus
e-mail: sakari.ailus-X3B1VOXEql0@public.gmane.org	XMPP: sailus-PCDdDYkjdNMDXYZnReoRVg@public.gmane.org
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Re: [PATCH v3 1/2] [media] dt-bindings: Add bindings for video-multiplexer device

[Sebastian Reichel]

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Hi,

On Thu, May 04, 2017 at 03:38:56PM +0200, Philipp Zabel wrote:
> Add bindings documentation for the video multiplexer device.
> 
> Signed-off-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Signed-off-by: Steve Longerbeam <steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
> Acked-by: Peter Rosin <peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
> Acked-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

Reviewed-by: Sebastian Reichel <sebastian.reichel-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>

-- Sebastian

> ---
> No changes since v2 [1].
> 
> This was previously sent as part of Steve's i.MX media series [2].
> 
> [1] https://patchwork.kernel.org/patch/9708235/
> [2] https://patchwork.kernel.org/patch/9647951/
> ---
>  .../devicetree/bindings/media/video-mux.txt        | 60 ++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/video-mux.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/video-mux.txt b/Documentation/devicetree/bindings/media/video-mux.txt
> new file mode 100644
> index 0000000000000..63b9dc913e456
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/video-mux.txt
> @@ -0,0 +1,60 @@
> +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 are controlled by a multiplexer controller that is described by
> +the bindings in Documentation/devicetree/bindings/mux/mux-controller.txt
> +
> +Required properties:
> +- compatible : should be "video-mux"
> +- mux-controls : mux controller node to use for operating the mux
> +- #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.
> +
> +Optionally, #address-cells, #size-cells, and port nodes can be grouped under a
> +ports node as described in Documentation/devicetree/bindings/graph.txt.
> +
> +Example:
> +
> +	mux: mux-controller {
> +		compatible = "gpio-mux";
> +		#mux-control-cells = <0>;
> +
> +		mux-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
> +	};
> +
> +	video-mux {
> +		compatible = "video-mux";
> +		mux-controls = <&mux>;
> +		#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>;
> +			};
> +		};
> +	};
> +};
> -- 
> 2.11.0
> 

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