On 2017-04-28 16:13, 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@xxxxxxxxxxxxxx> > Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx> > --- > This has been last sent as part of the i.MX media series. > > Changes since https://patchwork.kernel.org/patch/9647869/: > - Split out the actual mux operation to be provided by the mux controller > framework [1]. GPIO and MMIO control can be provided by individual mux > controller drivers [2][3]. > [1] https://patchwork.kernel.org/patch/9695837/ > [2] https://patchwork.kernel.org/patch/9695839/ > [3] https://patchwork.kernel.org/patch/9704509/ > - Shortened 'video-multiplexer' to 'video-mux', replaced all instances of > vidsw with video_mux. > - Made the mux inactive by default, only activated by user interaction. > - Added CONFIG_OF and CONFIG_MULTIPLEXER dependencies. > - Reuse subdev.entity.num_pads instead of keeping our own count. > - Removed implicit link disabling. Instead, trying to enable a second > sink pad link yields -EBUSY. > - Merged _async_init into _probe. > - Removed superfluous pad index check from _set_format. > - Added is_source_pad helper to tell source and sink pads apart. > - Removed test for status property in endpoint nodes. Disable the remote > device or sever the endpoint link to disable a sink pad. > --- > drivers/media/platform/Kconfig | 6 + > drivers/media/platform/Makefile | 2 + > drivers/media/platform/video-mux.c | 341 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 349 insertions(+) > create mode 100644 drivers/media/platform/video-mux.c > > diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig > index c9106e105baba..b046a6d39fee5 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 349ddf6a69da2..fd2735ca3ff75 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-$(CONFIG_VIDEO_MUX) += video-mux.o > + > obj-$(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..419541729f67e > --- /dev/null > +++ b/drivers/media/platform/video-mux.c > @@ -0,0 +1,341 @@ > +/* > + * video stream multiplexer controlled via mux control > + * > + * Copyright (C) 2013 Pengutronix, Sascha Hauer <kernel@xxxxxxxxxxxxxx> > + * Copyright (C) 2016 Pengutronix, Philipp Zabel <kernel@xxxxxxxxxxxxxx> 2017? > + * > + * 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/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-subdev.h> > +#include <media/v4l2-of.h> > + > +struct video_mux { > + struct v4l2_subdev subdev; > + struct media_pad *pads; > + struct v4l2_mbus_framefmt *format_mbus; > + struct v4l2_of_endpoint *endpoint; > + struct mux_control *mux; > + 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 inline bool is_source_pad(struct video_mux *vmux, unsigned int pad) > +{ > + return pad == vmux->subdev.entity.num_pads - 1; > +} > + > +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; > + > + /* > + * The mux state is determined by the enabled sink pad link. > + * Enabling or disabling the source pad link has no effect. > + */ > + if (is_source_pad(vmux, local->index)) > + 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); > + > + if (flags & MEDIA_LNK_FL_ENABLED) { > + if (vmux->active == local->index) Here, you shortcut the mux_control_select_trylock test and return "OK" based on a driver-local variable that is intended to keep track of mux ownership. > + return 0; > + > + if (vmux->active >= 0) Here too (and this check is not needed, the situation will be covered by the mux_control_try_select call). > + return -EBUSY; > + > + dev_dbg(sd->dev, "setting %d active\n", local->index); > + ret = mux_control_try_select(vmux->mux, local->index); > + if (ret < 0) > + return ret; > + vmux->active = local->index; > + } else { > + if (vmux->active != local->index) > + return 0; > + > + dev_dbg(sd->dev, "going inactive\n"); > + mux_control_deselect(vmux->mux); But here you let go of the mux *before* you clear the driver-local ownership indicator. That looks suspicious. My guess is that this is "safe" because the upper layers has some serialization, but I don't know. Anyway, even if there is something saving you in the upper layers, it looks out of order and unneeded. I would have moved the below vmux->active = -1; statement up to before the above deselect. With that fixed, mux usage looks good to me, so you can add an Acked- by from me if you wish (goes for the bindings patch as well). Cheers, peda > + vmux->active = -1; > + } > + > + return 0; > +} > + > +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_g_mbus_config(struct v4l2_subdev *sd, > + struct v4l2_mbus_config *cfg) > +{ > + struct video_mux *vmux = v4l2_subdev_to_video_mux(sd); > + struct v4l2_of_endpoint *endpoint; > + struct media_pad *pad; > + int ret; > + > + if (vmux->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(&vmux->pads[vmux->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) { > + endpoint = &vmux->endpoint[vmux->active]; > + > + /* Mirror the input side on the output side */ > + cfg->type = endpoint->bus_type; > + if (cfg->type == V4L2_MBUS_PARALLEL || > + cfg->type == V4L2_MBUS_BT656) > + cfg->flags = endpoint->bus.parallel.flags; > + } > + > + return 0; > +} > + > +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 = { > + .g_mbus_config = video_mux_g_mbus_config, > + .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) > +{ > + sdformat->format = *__video_mux_get_pad_format(sd, cfg, sdformat->pad, > + sdformat->which); > + 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; > + > + mbusformat = __video_mux_get_pad_format(sd, cfg, sdformat->pad, > + sdformat->which); > + if (!mbusformat) > + return -EINVAL; > + > + /* Source pad mirrors active sink pad, no limitations on sink pads */ > + if (is_source_pad(vmux, sdformat->pad) && vmux->active >= 0) > + sdformat->format = vmux->format_mbus[vmux->active]; > + > + *mbusformat = sdformat->format; > + > + return 0; > +} > + > +static struct v4l2_subdev_pad_ops video_mux_pad_ops = { > + .get_fmt = video_mux_get_format, > + .set_fmt = video_mux_set_format, > +}; > + > +static 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 v4l2_of_endpoint endpoint; > + 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) { > + of_graph_parse_endpoint(ep, &endpoint.base); > + num_pads = max(num_pads, endpoint.base.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; > + } > + > + 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) { > + v4l2_of_parse_endpoint(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"); >
