On 2017-04-29 23:29, Peter Rosin wrote: > 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). Ouch, that was a bit too soon. If there is *no* serialization in the upper layers, this is *not* ok, even with my reordering. There must be only one call to mux_control_deselect, and w/o serialization there is a race where you might get multiple deselect calls when several callers makes it through the active != index check before any of them manages to set active = -1. That race must be taken care of! 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"); >> >
