drivers/media/platform/video-mux.c

   1 /*
   2  * video stream multiplexer controlled via mux control
   3  *
   4  * Copyright (C) 2013 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
   5  * Copyright (C) 2016-2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/module.h>
  19 #include <linux/mutex.h>
  20 #include <linux/mux/consumer.h>
  21 #include <linux/of.h>
  22 #include <linux/of_graph.h>
  23 #include <linux/platform_device.h>
  24 #include <media/v4l2-async.h>
  25 #include <media/v4l2-device.h>
  26 #include <media/v4l2-subdev.h>
  27
  28 struct video_mux {
  29         struct v4l2_subdev subdev;
  30         struct media_pad *pads;
  31         struct v4l2_mbus_framefmt *format_mbus;
  32         struct mux_control *mux;
  33         struct mutex lock;
  34         int active;
  35 };
  36
  37 static inline struct video_mux *v4l2_subdev_to_video_mux(struct v4l2_subdev *sd)
  38 {
  39         return container_of(sd, struct video_mux, subdev);
  40 }
  41
  42 static int video_mux_link_setup(struct media_entity *entity,
  43                                 const struct media_pad *local,
  44                                 const struct media_pad *remote, u32 flags)
  45 {
  46         struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
  47         struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
  48         int ret = 0;
  49
  50         /*
  51          * The mux state is determined by the enabled sink pad link.
  52          * Enabling or disabling the source pad link has no effect.
  53          */
  54         if (local->flags & MEDIA_PAD_FL_SOURCE)
  55                 return 0;
  56
  57         dev_dbg(sd->dev, "link setup '%s':%d->'%s':%d[%d]",
  58                 remote->entity->name, remote->index, local->entity->name,
  59                 local->index, flags & MEDIA_LNK_FL_ENABLED);
  60
  61         mutex_lock(&vmux->lock);
  62
  63         if (flags & MEDIA_LNK_FL_ENABLED) {
  64                 if (vmux->active == local->index)
  65                         goto out;
  66
  67                 if (vmux->active >= 0) {
  68                         ret = -EBUSY;
  69                         goto out;
  70                 }
  71
  72                 dev_dbg(sd->dev, "setting %d active\n", local->index);
  73                 ret = mux_control_try_select(vmux->mux, local->index);
  74                 if (ret < 0)
  75                         goto out;
  76                 vmux->active = local->index;
  77         } else {
  78                 if (vmux->active != local->index)
  79                         goto out;
  80
  81                 dev_dbg(sd->dev, "going inactive\n");
  82                 mux_control_deselect(vmux->mux);
  83                 vmux->active = -1;
  84         }
  85
  86 out:
  87         mutex_unlock(&vmux->lock);
  88         return ret;
  89 }
  90
  91 static const struct media_entity_operations video_mux_ops = {
  92         .link_setup = video_mux_link_setup,
  93         .link_validate = v4l2_subdev_link_validate,
  94 };
  95
  96 static int video_mux_s_stream(struct v4l2_subdev *sd, int enable)
  97 {
  98         struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
  99         struct v4l2_subdev *upstream_sd;
 100         struct media_pad *pad;
 101
 102         if (vmux->active == -1) {
 103                 dev_err(sd->dev, "Can not start streaming on inactive mux\n");
 104                 return -EINVAL;
 105         }
 106
 107         pad = media_entity_remote_pad(&sd->entity.pads[vmux->active]);
 108         if (!pad) {
 109                 dev_err(sd->dev, "Failed to find remote source pad\n");
 110                 return -ENOLINK;
 111         }
 112
 113         if (!is_media_entity_v4l2_subdev(pad->entity)) {
 114                 dev_err(sd->dev, "Upstream entity is not a v4l2 subdev\n");
 115                 return -ENODEV;
 116         }
 117
 118         upstream_sd = media_entity_to_v4l2_subdev(pad->entity);
 119
 120         return v4l2_subdev_call(upstream_sd, video, s_stream, enable);
 121 }
 122
 123 static const struct v4l2_subdev_video_ops video_mux_subdev_video_ops = {
 124         .s_stream = video_mux_s_stream,
 125 };
 126
 127 static struct v4l2_mbus_framefmt *
 128 __video_mux_get_pad_format(struct v4l2_subdev *sd,
 129                            struct v4l2_subdev_pad_config *cfg,
 130                            unsigned int pad, u32 which)
 131 {
 132         struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
 133
 134         switch (which) {
 135         case V4L2_SUBDEV_FORMAT_TRY:
 136                 return v4l2_subdev_get_try_format(sd, cfg, pad);
 137         case V4L2_SUBDEV_FORMAT_ACTIVE:
 138                 return &vmux->format_mbus[pad];
 139         default:
 140                 return NULL;
 141         }
 142 }
 143
 144 static int video_mux_get_format(struct v4l2_subdev *sd,
 145                             struct v4l2_subdev_pad_config *cfg,
 146                             struct v4l2_subdev_format *sdformat)
 147 {
 148         struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
 149
 150         mutex_lock(&vmux->lock);
 151
 152         sdformat->format = *__video_mux_get_pad_format(sd, cfg, sdformat->pad,
 153                                                        sdformat->which);
 154
 155         mutex_unlock(&vmux->lock);
 156
 157         return 0;
 158 }
 159
 160 static int video_mux_set_format(struct v4l2_subdev *sd,
 161                             struct v4l2_subdev_pad_config *cfg,
 162                             struct v4l2_subdev_format *sdformat)
 163 {
 164         struct video_mux *vmux = v4l2_subdev_to_video_mux(sd);
 165         struct v4l2_mbus_framefmt *mbusformat;
 166         struct media_pad *pad = &vmux->pads[sdformat->pad];
 167
 168         mbusformat = __video_mux_get_pad_format(sd, cfg, sdformat->pad,
 169                                             sdformat->which);
 170         if (!mbusformat)
 171                 return -EINVAL;
 172
 173         mutex_lock(&vmux->lock);
 174
 175         /* Source pad mirrors active sink pad, no limitations on sink pads */
 176         if ((pad->flags & MEDIA_PAD_FL_SOURCE) && vmux->active >= 0)
 177                 sdformat->format = vmux->format_mbus[vmux->active];
 178
 179         *mbusformat = sdformat->format;
 180
 181         mutex_unlock(&vmux->lock);
 182
 183         return 0;
 184 }
 185
 186 static const struct v4l2_subdev_pad_ops video_mux_pad_ops = {
 187         .get_fmt = video_mux_get_format,
 188         .set_fmt = video_mux_set_format,
 189 };
 190
 191 static const struct v4l2_subdev_ops video_mux_subdev_ops = {
 192         .pad = &video_mux_pad_ops,
 193         .video = &video_mux_subdev_video_ops,
 194 };
 195
 196 static int video_mux_probe(struct platform_device *pdev)
 197 {
 198         struct device_node *np = pdev->dev.of_node;
 199         struct device *dev = &pdev->dev;
 200         struct device_node *ep;
 201         struct video_mux *vmux;
 202         unsigned int num_pads = 0;
 203         int ret;
 204         int i;
 205
 206         vmux = devm_kzalloc(dev, sizeof(*vmux), GFP_KERNEL);
 207         if (!vmux)
 208                 return -ENOMEM;
 209
 210         platform_set_drvdata(pdev, vmux);
 211
 212         v4l2_subdev_init(&vmux->subdev, &video_mux_subdev_ops);
 213         snprintf(vmux->subdev.name, sizeof(vmux->subdev.name), "%s", np->name);
 214         vmux->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 215         vmux->subdev.dev = dev;
 216
 217         /*
 218          * The largest numbered port is the output port. It determines
 219          * total number of pads.
 220          */
 221         for_each_endpoint_of_node(np, ep) {
 222                 struct of_endpoint endpoint;
 223
 224                 of_graph_parse_endpoint(ep, &endpoint);
 225                 num_pads = max(num_pads, endpoint.port + 1);
 226         }
 227
 228         if (num_pads < 2) {
 229                 dev_err(dev, "Not enough ports %d\n", num_pads);
 230                 return -EINVAL;
 231         }
 232
 233         vmux->mux = devm_mux_control_get(dev, NULL);
 234         if (IS_ERR(vmux->mux)) {
 235                 ret = PTR_ERR(vmux->mux);
 236                 if (ret != -EPROBE_DEFER)
 237                         dev_err(dev, "Failed to get mux: %d\n", ret);
 238                 return ret;
 239         }
 240
 241         mutex_init(&vmux->lock);
 242         vmux->active = -1;
 243         vmux->pads = devm_kcalloc(dev, num_pads, sizeof(*vmux->pads),
 244                                   GFP_KERNEL);
 245         if (!vmux->pads)
 246                 return -ENOMEM;
 247
 248         vmux->format_mbus = devm_kcalloc(dev, num_pads,
 249                                          sizeof(*vmux->format_mbus),
 250                                          GFP_KERNEL);
 251         if (!vmux->format_mbus)
 252                 return -ENOMEM;
 253
 254         for (i = 0; i < num_pads - 1; i++)
 255                 vmux->pads[i].flags = MEDIA_PAD_FL_SINK;
 256         vmux->pads[num_pads - 1].flags = MEDIA_PAD_FL_SOURCE;
 257
 258         vmux->subdev.entity.function = MEDIA_ENT_F_VID_MUX;
 259         ret = media_entity_pads_init(&vmux->subdev.entity, num_pads,
 260                                      vmux->pads);
 261         if (ret < 0)
 262                 return ret;
 263
 264         vmux->subdev.entity.ops = &video_mux_ops;
 265
 266         return v4l2_async_register_subdev(&vmux->subdev);
 267 }
 268
 269 static int video_mux_remove(struct platform_device *pdev)
 270 {
 271         struct video_mux *vmux = platform_get_drvdata(pdev);
 272         struct v4l2_subdev *sd = &vmux->subdev;
 273
 274         v4l2_async_unregister_subdev(sd);
 275         media_entity_cleanup(&sd->entity);
 276
 277         return 0;
 278 }
 279
 280 static const struct of_device_id video_mux_dt_ids[] = {
 281         { .compatible = "video-mux", },
 282         { /* sentinel */ }
 283 };
 284 MODULE_DEVICE_TABLE(of, video_mux_dt_ids);
 285
 286 static struct platform_driver video_mux_driver = {
 287         .probe          = video_mux_probe,
 288         .remove         = video_mux_remove,
 289         .driver         = {
 290                 .of_match_table = video_mux_dt_ids,
 291                 .name = "video-mux",
 292         },
 293 };
 294
 295 module_platform_driver(video_mux_driver);
 296
 297 MODULE_DESCRIPTION("video stream multiplexer");
 298 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
 299 MODULE_AUTHOR("Philipp Zabel, Pengutronix");
 300 MODULE_LICENSE("GPL");