drivers/staging/imx-drm/imx-drm-core.c

   1 /*
   2  * Freescale i.MX drm driver
   3  *
   4  * Copyright (C) 2011 Sascha Hauer, Pengutronix
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16 #include <linux/component.h>
  17 #include <linux/device.h>
  18 #include <linux/fb.h>
  19 #include <linux/module.h>
  20 #include <linux/of_graph.h>
  21 #include <linux/platform_device.h>
  22 #include <drm/drmP.h>
  23 #include <drm/drm_fb_helper.h>
  24 #include <drm/drm_crtc_helper.h>
  25 #include <drm/drm_gem_cma_helper.h>
  26 #include <drm/drm_fb_cma_helper.h>
  27
  28 #include "imx-drm.h"
  29
  30 #define MAX_CRTC        4
  31
  32 struct imx_drm_crtc;
  33
  34 struct imx_drm_component {
  35         struct device_node *of_node;
  36         struct list_head list;
  37 };
  38
  39 struct imx_drm_device {
  40         struct drm_device                       *drm;
  41         struct imx_drm_crtc                     *crtc[MAX_CRTC];
  42         int                                     pipes;
  43         struct drm_fbdev_cma                    *fbhelper;
  44 };
  45
  46 struct imx_drm_crtc {
  47         struct drm_crtc                         *crtc;
  48         int                                     pipe;
  49         struct imx_drm_crtc_helper_funcs        imx_drm_helper_funcs;
  50         struct device_node                      *port;
  51 };
  52
  53 static int legacyfb_depth = 16;
  54 module_param(legacyfb_depth, int, 0444);
  55
  56 int imx_drm_crtc_id(struct imx_drm_crtc *crtc)
  57 {
  58         return crtc->pipe;
  59 }
  60 EXPORT_SYMBOL_GPL(imx_drm_crtc_id);
  61
  62 static void imx_drm_driver_lastclose(struct drm_device *drm)
  63 {
  64 #if IS_ENABLED(CONFIG_DRM_IMX_FB_HELPER)
  65         struct imx_drm_device *imxdrm = drm->dev_private;
  66
  67         if (imxdrm->fbhelper)
  68                 drm_fbdev_cma_restore_mode(imxdrm->fbhelper);
  69 #endif
  70 }
  71
  72 static int imx_drm_driver_unload(struct drm_device *drm)
  73 {
  74 #if IS_ENABLED(CONFIG_DRM_IMX_FB_HELPER)
  75         struct imx_drm_device *imxdrm = drm->dev_private;
  76 #endif
  77
  78         drm_kms_helper_poll_fini(drm);
  79
  80 #if IS_ENABLED(CONFIG_DRM_IMX_FB_HELPER)
  81         if (imxdrm->fbhelper)
  82                 drm_fbdev_cma_fini(imxdrm->fbhelper);
  83 #endif
  84
  85         component_unbind_all(drm->dev, drm);
  86
  87         drm_vblank_cleanup(drm);
  88         drm_mode_config_cleanup(drm);
  89
  90         return 0;
  91 }
  92
  93 static struct imx_drm_crtc *imx_drm_find_crtc(struct drm_crtc *crtc)
  94 {
  95         struct imx_drm_device *imxdrm = crtc->dev->dev_private;
  96         unsigned i;
  97
  98         for (i = 0; i < MAX_CRTC; i++)
  99                 if (imxdrm->crtc[i] && imxdrm->crtc[i]->crtc == crtc)
 100                         return imxdrm->crtc[i];
 101
 102         return NULL;
 103 }
 104
 105 int imx_drm_panel_format_pins(struct drm_encoder *encoder,
 106                 u32 interface_pix_fmt, int hsync_pin, int vsync_pin)
 107 {
 108         struct imx_drm_crtc_helper_funcs *helper;
 109         struct imx_drm_crtc *imx_crtc;
 110
 111         imx_crtc = imx_drm_find_crtc(encoder->crtc);
 112         if (!imx_crtc)
 113                 return -EINVAL;
 114
 115         helper = &imx_crtc->imx_drm_helper_funcs;
 116         if (helper->set_interface_pix_fmt)
 117                 return helper->set_interface_pix_fmt(encoder->crtc,
 118                                 encoder->encoder_type, interface_pix_fmt,
 119                                 hsync_pin, vsync_pin);
 120         return 0;
 121 }
 122 EXPORT_SYMBOL_GPL(imx_drm_panel_format_pins);
 123
 124 int imx_drm_panel_format(struct drm_encoder *encoder, u32 interface_pix_fmt)
 125 {
 126         return imx_drm_panel_format_pins(encoder, interface_pix_fmt, 2, 3);
 127 }
 128 EXPORT_SYMBOL_GPL(imx_drm_panel_format);
 129
 130 int imx_drm_crtc_vblank_get(struct imx_drm_crtc *imx_drm_crtc)
 131 {
 132         return drm_vblank_get(imx_drm_crtc->crtc->dev, imx_drm_crtc->pipe);
 133 }
 134 EXPORT_SYMBOL_GPL(imx_drm_crtc_vblank_get);
 135
 136 void imx_drm_crtc_vblank_put(struct imx_drm_crtc *imx_drm_crtc)
 137 {
 138         drm_vblank_put(imx_drm_crtc->crtc->dev, imx_drm_crtc->pipe);
 139 }
 140 EXPORT_SYMBOL_GPL(imx_drm_crtc_vblank_put);
 141
 142 void imx_drm_handle_vblank(struct imx_drm_crtc *imx_drm_crtc)
 143 {
 144         drm_handle_vblank(imx_drm_crtc->crtc->dev, imx_drm_crtc->pipe);
 145 }
 146 EXPORT_SYMBOL_GPL(imx_drm_handle_vblank);
 147
 148 static int imx_drm_enable_vblank(struct drm_device *drm, int crtc)
 149 {
 150         struct imx_drm_device *imxdrm = drm->dev_private;
 151         struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[crtc];
 152         int ret;
 153
 154         if (!imx_drm_crtc)
 155                 return -EINVAL;
 156
 157         if (!imx_drm_crtc->imx_drm_helper_funcs.enable_vblank)
 158                 return -ENOSYS;
 159
 160         ret = imx_drm_crtc->imx_drm_helper_funcs.enable_vblank(
 161                         imx_drm_crtc->crtc);
 162
 163         return ret;
 164 }
 165
 166 static void imx_drm_disable_vblank(struct drm_device *drm, int crtc)
 167 {
 168         struct imx_drm_device *imxdrm = drm->dev_private;
 169         struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[crtc];
 170
 171         if (!imx_drm_crtc)
 172                 return;
 173
 174         if (!imx_drm_crtc->imx_drm_helper_funcs.disable_vblank)
 175                 return;
 176
 177         imx_drm_crtc->imx_drm_helper_funcs.disable_vblank(imx_drm_crtc->crtc);
 178 }
 179
 180 static void imx_drm_driver_preclose(struct drm_device *drm,
 181                 struct drm_file *file)
 182 {
 183         int i;
 184
 185         if (!file->is_master)
 186                 return;
 187
 188         for (i = 0; i < MAX_CRTC; i++)
 189                 imx_drm_disable_vblank(drm, i);
 190 }
 191
 192 static const struct file_operations imx_drm_driver_fops = {
 193         .owner = THIS_MODULE,
 194         .open = drm_open,
 195         .release = drm_release,
 196         .unlocked_ioctl = drm_ioctl,
 197         .mmap = drm_gem_cma_mmap,
 198         .poll = drm_poll,
 199         .read = drm_read,
 200         .llseek = noop_llseek,
 201 };
 202
 203 int imx_drm_connector_mode_valid(struct drm_connector *connector,
 204         struct drm_display_mode *mode)
 205 {
 206         return MODE_OK;
 207 }
 208 EXPORT_SYMBOL(imx_drm_connector_mode_valid);
 209
 210 void imx_drm_connector_destroy(struct drm_connector *connector)
 211 {
 212         drm_sysfs_connector_remove(connector);
 213         drm_connector_cleanup(connector);
 214 }
 215 EXPORT_SYMBOL_GPL(imx_drm_connector_destroy);
 216
 217 void imx_drm_encoder_destroy(struct drm_encoder *encoder)
 218 {
 219         drm_encoder_cleanup(encoder);
 220 }
 221 EXPORT_SYMBOL_GPL(imx_drm_encoder_destroy);
 222
 223 static void imx_drm_output_poll_changed(struct drm_device *drm)
 224 {
 225 #if IS_ENABLED(CONFIG_DRM_IMX_FB_HELPER)
 226         struct imx_drm_device *imxdrm = drm->dev_private;
 227
 228         drm_fbdev_cma_hotplug_event(imxdrm->fbhelper);
 229 #endif
 230 }
 231
 232 static struct drm_mode_config_funcs imx_drm_mode_config_funcs = {
 233         .fb_create = drm_fb_cma_create,
 234         .output_poll_changed = imx_drm_output_poll_changed,
 235 };
 236
 237 /*
 238  * Main DRM initialisation. This binds, initialises and registers
 239  * with DRM the subcomponents of the driver.
 240  */
 241 static int imx_drm_driver_load(struct drm_device *drm, unsigned long flags)
 242 {
 243         struct imx_drm_device *imxdrm;
 244         struct drm_connector *connector;
 245         int ret;
 246
 247         imxdrm = devm_kzalloc(drm->dev, sizeof(*imxdrm), GFP_KERNEL);
 248         if (!imxdrm)
 249                 return -ENOMEM;
 250
 251         imxdrm->drm = drm;
 252
 253         drm->dev_private = imxdrm;
 254
 255         /*
 256          * enable drm irq mode.
 257          * - with irq_enabled = true, we can use the vblank feature.
 258          *
 259          * P.S. note that we wouldn't use drm irq handler but
 260          *      just specific driver own one instead because
 261          *      drm framework supports only one irq handler and
 262          *      drivers can well take care of their interrupts
 263          */
 264         drm->irq_enabled = true;
 265
 266         /*
 267          * set max width and height as default value(4096x4096).
 268          * this value would be used to check framebuffer size limitation
 269          * at drm_mode_addfb().
 270          */
 271         drm->mode_config.min_width = 64;
 272         drm->mode_config.min_height = 64;
 273         drm->mode_config.max_width = 4096;
 274         drm->mode_config.max_height = 4096;
 275         drm->mode_config.funcs = &imx_drm_mode_config_funcs;
 276
 277         drm_mode_config_init(drm);
 278
 279         ret = drm_vblank_init(drm, MAX_CRTC);
 280         if (ret)
 281                 goto err_kms;
 282
 283         /*
 284          * with vblank_disable_allowed = true, vblank interrupt will be
 285          * disabled by drm timer once a current process gives up ownership
 286          * of vblank event. (after drm_vblank_put function is called)
 287          */
 288         drm->vblank_disable_allowed = true;
 289
 290         platform_set_drvdata(drm->platformdev, drm);
 291
 292         /* Now try and bind all our sub-components */
 293         ret = component_bind_all(drm->dev, drm);
 294         if (ret)
 295                 goto err_vblank;
 296
 297         /*
 298          * All components are now added, we can publish the connector sysfs
 299          * entries to userspace.  This will generate hotplug events and so
 300          * userspace will expect to be able to access DRM at this point.
 301          */
 302         list_for_each_entry(connector, &drm->mode_config.connector_list, head) {
 303                 ret = drm_sysfs_connector_add(connector);
 304                 if (ret) {
 305                         dev_err(drm->dev,
 306                                 "[CONNECTOR:%d:%s] drm_sysfs_connector_add failed: %d\n",
 307                                 connector->base.id,
 308                                 drm_get_connector_name(connector), ret);
 309                         goto err_unbind;
 310                 }
 311         }
 312
 313         /*
 314          * All components are now initialised, so setup the fb helper.
 315          * The fb helper takes copies of key hardware information, so the
 316          * crtcs/connectors/encoders must not change after this point.
 317          */
 318 #if IS_ENABLED(CONFIG_DRM_IMX_FB_HELPER)
 319         if (legacyfb_depth != 16 && legacyfb_depth != 32) {
 320                 dev_warn(drm->dev, "Invalid legacyfb_depth.  Defaulting to 16bpp\n");
 321                 legacyfb_depth = 16;
 322         }
 323         imxdrm->fbhelper = drm_fbdev_cma_init(drm, legacyfb_depth,
 324                                 drm->mode_config.num_crtc, MAX_CRTC);
 325         if (IS_ERR(imxdrm->fbhelper)) {
 326                 ret = PTR_ERR(imxdrm->fbhelper);
 327                 imxdrm->fbhelper = NULL;
 328                 goto err_unbind;
 329         }
 330 #endif
 331
 332         drm_kms_helper_poll_init(drm);
 333
 334         return 0;
 335
 336 err_unbind:
 337         component_unbind_all(drm->dev, drm);
 338 err_vblank:
 339         drm_vblank_cleanup(drm);
 340 err_kms:
 341         drm_mode_config_cleanup(drm);
 342
 343         return ret;
 344 }
 345
 346 /*
 347  * imx_drm_add_crtc - add a new crtc
 348  */
 349 int imx_drm_add_crtc(struct drm_device *drm, struct drm_crtc *crtc,
 350                 struct imx_drm_crtc **new_crtc,
 351                 const struct imx_drm_crtc_helper_funcs *imx_drm_helper_funcs,
 352                 struct device_node *port)
 353 {
 354         struct imx_drm_device *imxdrm = drm->dev_private;
 355         struct imx_drm_crtc *imx_drm_crtc;
 356         int ret;
 357
 358         /*
 359          * The vblank arrays are dimensioned by MAX_CRTC - we can't
 360          * pass IDs greater than this to those functions.
 361          */
 362         if (imxdrm->pipes >= MAX_CRTC)
 363                 return -EINVAL;
 364
 365         if (imxdrm->drm->open_count)
 366                 return -EBUSY;
 367
 368         imx_drm_crtc = kzalloc(sizeof(*imx_drm_crtc), GFP_KERNEL);
 369         if (!imx_drm_crtc)
 370                 return -ENOMEM;
 371
 372         imx_drm_crtc->imx_drm_helper_funcs = *imx_drm_helper_funcs;
 373         imx_drm_crtc->pipe = imxdrm->pipes++;
 374         imx_drm_crtc->port = port;
 375         imx_drm_crtc->crtc = crtc;
 376
 377         imxdrm->crtc[imx_drm_crtc->pipe] = imx_drm_crtc;
 378
 379         *new_crtc = imx_drm_crtc;
 380
 381         ret = drm_mode_crtc_set_gamma_size(imx_drm_crtc->crtc, 256);
 382         if (ret)
 383                 goto err_register;
 384
 385         drm_crtc_helper_add(crtc,
 386                         imx_drm_crtc->imx_drm_helper_funcs.crtc_helper_funcs);
 387
 388         drm_crtc_init(drm, crtc,
 389                         imx_drm_crtc->imx_drm_helper_funcs.crtc_funcs);
 390
 391         return 0;
 392
 393 err_register:
 394         imxdrm->crtc[imx_drm_crtc->pipe] = NULL;
 395         kfree(imx_drm_crtc);
 396         return ret;
 397 }
 398 EXPORT_SYMBOL_GPL(imx_drm_add_crtc);
 399
 400 /*
 401  * imx_drm_remove_crtc - remove a crtc
 402  */
 403 int imx_drm_remove_crtc(struct imx_drm_crtc *imx_drm_crtc)
 404 {
 405         struct imx_drm_device *imxdrm = imx_drm_crtc->crtc->dev->dev_private;
 406
 407         drm_crtc_cleanup(imx_drm_crtc->crtc);
 408
 409         imxdrm->crtc[imx_drm_crtc->pipe] = NULL;
 410
 411         kfree(imx_drm_crtc);
 412
 413         return 0;
 414 }
 415 EXPORT_SYMBOL_GPL(imx_drm_remove_crtc);
 416
 417 /*
 418  * Find the DRM CRTC possible mask for the connected endpoint.
 419  *
 420  * The encoder possible masks are defined by their position in the
 421  * mode_config crtc_list.  This means that CRTCs must not be added
 422  * or removed once the DRM device has been fully initialised.
 423  */
 424 static uint32_t imx_drm_find_crtc_mask(struct imx_drm_device *imxdrm,
 425         struct device_node *endpoint)
 426 {
 427         struct device_node *port;
 428         unsigned i;
 429
 430         port = of_graph_get_remote_port(endpoint);
 431         if (!port)
 432                 return 0;
 433         of_node_put(port);
 434
 435         for (i = 0; i < MAX_CRTC; i++) {
 436                 struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[i];
 437                 if (imx_drm_crtc && imx_drm_crtc->port == port)
 438                         return drm_crtc_mask(imx_drm_crtc->crtc);
 439         }
 440
 441         return 0;
 442 }
 443
 444 static struct device_node *imx_drm_of_get_next_endpoint(
 445                 const struct device_node *parent, struct device_node *prev)
 446 {
 447         struct device_node *node = of_graph_get_next_endpoint(parent, prev);
 448         of_node_put(prev);
 449         return node;
 450 }
 451
 452 int imx_drm_encoder_parse_of(struct drm_device *drm,
 453         struct drm_encoder *encoder, struct device_node *np)
 454 {
 455         struct imx_drm_device *imxdrm = drm->dev_private;
 456         struct device_node *ep = NULL;
 457         uint32_t crtc_mask = 0;
 458         int i;
 459
 460         for (i = 0; ; i++) {
 461                 u32 mask;
 462
 463                 ep = imx_drm_of_get_next_endpoint(np, ep);
 464                 if (!ep)
 465                         break;
 466
 467                 mask = imx_drm_find_crtc_mask(imxdrm, ep);
 468
 469                 /*
 470                  * If we failed to find the CRTC(s) which this encoder is
 471                  * supposed to be connected to, it's because the CRTC has
 472                  * not been registered yet.  Defer probing, and hope that
 473                  * the required CRTC is added later.
 474                  */
 475                 if (mask == 0)
 476                         return -EPROBE_DEFER;
 477
 478                 crtc_mask |= mask;
 479         }
 480
 481         if (ep)
 482                 of_node_put(ep);
 483         if (i == 0)
 484                 return -ENOENT;
 485
 486         encoder->possible_crtcs = crtc_mask;
 487
 488         /* FIXME: this is the mask of outputs which can clone this output. */
 489         encoder->possible_clones = ~0;
 490
 491         return 0;
 492 }
 493 EXPORT_SYMBOL_GPL(imx_drm_encoder_parse_of);
 494
 495 /*
 496  * @node: device tree node containing encoder input ports
 497  * @encoder: drm_encoder
 498  */
 499 int imx_drm_encoder_get_mux_id(struct device_node *node,
 500                                struct drm_encoder *encoder)
 501 {
 502         struct imx_drm_crtc *imx_crtc = imx_drm_find_crtc(encoder->crtc);
 503         struct device_node *ep = NULL;
 504         struct of_endpoint endpoint;
 505         struct device_node *port;
 506         int ret;
 507
 508         if (!node || !imx_crtc)
 509                 return -EINVAL;
 510
 511         do {
 512                 ep = imx_drm_of_get_next_endpoint(node, ep);
 513                 if (!ep)
 514                         break;
 515
 516                 port = of_graph_get_remote_port(ep);
 517                 of_node_put(port);
 518                 if (port == imx_crtc->port) {
 519                         ret = of_graph_parse_endpoint(ep, &endpoint);
 520                         return ret ? ret : endpoint.port;
 521                 }
 522         } while (ep);
 523
 524         return -EINVAL;
 525 }
 526 EXPORT_SYMBOL_GPL(imx_drm_encoder_get_mux_id);
 527
 528 static const struct drm_ioctl_desc imx_drm_ioctls[] = {
 529         /* none so far */
 530 };
 531
 532 static struct drm_driver imx_drm_driver = {
 533         .driver_features        = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME,
 534         .load                   = imx_drm_driver_load,
 535         .unload                 = imx_drm_driver_unload,
 536         .lastclose              = imx_drm_driver_lastclose,
 537         .preclose               = imx_drm_driver_preclose,
 538         .gem_free_object        = drm_gem_cma_free_object,
 539         .gem_vm_ops             = &drm_gem_cma_vm_ops,
 540         .dumb_create            = drm_gem_cma_dumb_create,
 541         .dumb_map_offset        = drm_gem_cma_dumb_map_offset,
 542         .dumb_destroy           = drm_gem_dumb_destroy,
 543
 544         .prime_handle_to_fd     = drm_gem_prime_handle_to_fd,
 545         .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
 546         .gem_prime_import       = drm_gem_prime_import,
 547         .gem_prime_export       = drm_gem_prime_export,
 548         .gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
 549         .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
 550         .gem_prime_vmap         = drm_gem_cma_prime_vmap,
 551         .gem_prime_vunmap       = drm_gem_cma_prime_vunmap,
 552         .gem_prime_mmap         = drm_gem_cma_prime_mmap,
 553         .get_vblank_counter     = drm_vblank_count,
 554         .enable_vblank          = imx_drm_enable_vblank,
 555         .disable_vblank         = imx_drm_disable_vblank,
 556         .ioctls                 = imx_drm_ioctls,
 557         .num_ioctls             = ARRAY_SIZE(imx_drm_ioctls),
 558         .fops                   = &imx_drm_driver_fops,
 559         .name                   = "imx-drm",
 560         .desc                   = "i.MX DRM graphics",
 561         .date                   = "20120507",
 562         .major                  = 1,
 563         .minor                  = 0,
 564         .patchlevel             = 0,
 565 };
 566
 567 static int compare_of(struct device *dev, void *data)
 568 {
 569         struct device_node *np = data;
 570
 571         /* Special case for LDB, one device for two channels */
 572         if (of_node_cmp(np->name, "lvds-channel") == 0) {
 573                 np = of_get_parent(np);
 574                 of_node_put(np);
 575         }
 576
 577         return dev->of_node == np;
 578 }
 579
 580 static LIST_HEAD(imx_drm_components);
 581
 582 static int imx_drm_add_components(struct device *master, struct master *m)
 583 {
 584         struct imx_drm_component *component;
 585         int ret;
 586
 587         list_for_each_entry(component, &imx_drm_components, list) {
 588                 ret = component_master_add_child(m, compare_of,
 589                                                  component->of_node);
 590                 if (ret)
 591                         return ret;
 592         }
 593         return 0;
 594 }
 595
 596 static int imx_drm_bind(struct device *dev)
 597 {
 598         return drm_platform_init(&imx_drm_driver, to_platform_device(dev));
 599 }
 600
 601 static void imx_drm_unbind(struct device *dev)
 602 {
 603         drm_put_dev(dev_get_drvdata(dev));
 604 }
 605
 606 static const struct component_master_ops imx_drm_ops = {
 607         .add_components = imx_drm_add_components,
 608         .bind = imx_drm_bind,
 609         .unbind = imx_drm_unbind,
 610 };
 611
 612 static struct imx_drm_component *imx_drm_find_component(struct device *dev,
 613                 struct device_node *node)
 614 {
 615         struct imx_drm_component *component;
 616
 617         list_for_each_entry(component, &imx_drm_components, list)
 618                 if (component->of_node == node)
 619                         return component;
 620
 621         return NULL;
 622 }
 623
 624 static int imx_drm_add_component(struct device *dev, struct device_node *node)
 625 {
 626         struct imx_drm_component *component;
 627
 628         if (imx_drm_find_component(dev, node))
 629                 return 0;
 630
 631         component = devm_kzalloc(dev, sizeof(*component), GFP_KERNEL);
 632         if (!component)
 633                 return -ENOMEM;
 634
 635         component->of_node = node;
 636         list_add_tail(&component->list, &imx_drm_components);
 637
 638         return 0;
 639 }
 640
 641 static int imx_drm_platform_probe(struct platform_device *pdev)
 642 {
 643         struct device_node *ep, *port, *remote;
 644         int ret;
 645         int i;
 646
 647         /*
 648          * Bind the IPU display interface ports first, so that
 649          * imx_drm_encoder_parse_of called from encoder .bind callbacks
 650          * works as expected.
 651          */
 652         for (i = 0; ; i++) {
 653                 port = of_parse_phandle(pdev->dev.of_node, "ports", i);
 654                 if (!port)
 655                         break;
 656
 657                 ret = imx_drm_add_component(&pdev->dev, port);
 658                 if (ret < 0)
 659                         return ret;
 660         }
 661
 662         if (i == 0) {
 663                 dev_err(&pdev->dev, "missing 'ports' property\n");
 664                 return -ENODEV;
 665         }
 666
 667         /* Then bind all encoders */
 668         for (i = 0; ; i++) {
 669                 port = of_parse_phandle(pdev->dev.of_node, "ports", i);
 670                 if (!port)
 671                         break;
 672
 673                 for_each_child_of_node(port, ep) {
 674                         remote = of_graph_get_remote_port_parent(ep);
 675                         if (!remote || !of_device_is_available(remote)) {
 676                                 of_node_put(remote);
 677                                 continue;
 678                         } else if (!of_device_is_available(remote->parent)) {
 679                                 dev_warn(&pdev->dev, "parent device of %s is not available\n",
 680                                          remote->full_name);
 681                                 of_node_put(remote);
 682                                 continue;
 683                         }
 684
 685                         ret = imx_drm_add_component(&pdev->dev, remote);
 686                         of_node_put(remote);
 687                         if (ret < 0)
 688                                 return ret;
 689                 }
 690                 of_node_put(port);
 691         }
 692
 693         ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
 694         if (ret)
 695                 return ret;
 696
 697         return component_master_add(&pdev->dev, &imx_drm_ops);
 698 }
 699
 700 static int imx_drm_platform_remove(struct platform_device *pdev)
 701 {
 702         component_master_del(&pdev->dev, &imx_drm_ops);
 703         return 0;
 704 }
 705
 706 static const struct of_device_id imx_drm_dt_ids[] = {
 707         { .compatible = "fsl,imx-display-subsystem", },
 708         { /* sentinel */ },
 709 };
 710 MODULE_DEVICE_TABLE(of, imx_drm_dt_ids);
 711
 712 static struct platform_driver imx_drm_pdrv = {
 713         .probe          = imx_drm_platform_probe,
 714         .remove         = imx_drm_platform_remove,
 715         .driver         = {
 716                 .owner  = THIS_MODULE,
 717                 .name   = "imx-drm",
 718                 .of_match_table = imx_drm_dt_ids,
 719         },
 720 };
 721 module_platform_driver(imx_drm_pdrv);
 722
 723 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
 724 MODULE_DESCRIPTION("i.MX drm driver core");
 725 MODULE_LICENSE("GPL");