drivers/gpu/drm/vc4/vc4_dpi.c

   1 /*
   2  * Copyright (C) 2016 Broadcom Limited
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 /**
  18  * DOC: VC4 DPI module
  19  *
  20  * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI
  21  * signals.  On BCM2835, these can be routed out to GPIO0-27 with the
  22  * ALT2 function.
  23  */
  24
  25 #include "drm_atomic_helper.h"
  26 #include "drm_crtc_helper.h"
  27 #include "drm_edid.h"
  28 #include "drm_panel.h"
  29 #include "linux/clk.h"
  30 #include "linux/component.h"
  31 #include "linux/of_graph.h"
  32 #include "linux/of_platform.h"
  33 #include "vc4_drv.h"
  34 #include "vc4_regs.h"
  35
  36 #define DPI_C                   0x00
  37 # define DPI_OUTPUT_ENABLE_MODE         BIT(16)
  38
  39 /* The order field takes the incoming 24 bit RGB from the pixel valve
  40  * and shuffles the 3 channels.
  41  */
  42 # define DPI_ORDER_MASK                 VC4_MASK(15, 14)
  43 # define DPI_ORDER_SHIFT                14
  44 # define DPI_ORDER_RGB                  0
  45 # define DPI_ORDER_BGR                  1
  46 # define DPI_ORDER_GRB                  2
  47 # define DPI_ORDER_BRG                  3
  48
  49 /* The format field takes the ORDER-shuffled pixel valve data and
  50  * formats it onto the output lines.
  51  */
  52 # define DPI_FORMAT_MASK                VC4_MASK(13, 11)
  53 # define DPI_FORMAT_SHIFT               11
  54 /* This define is named in the hardware, but actually just outputs 0. */
  55 # define DPI_FORMAT_9BIT_666_RGB        0
  56 /* Outputs 00000000rrrrrggggggbbbbb */
  57 # define DPI_FORMAT_16BIT_565_RGB_1     1
  58 /* Outputs 000rrrrr00gggggg000bbbbb */
  59 # define DPI_FORMAT_16BIT_565_RGB_2     2
  60 /* Outputs 00rrrrr000gggggg00bbbbb0 */
  61 # define DPI_FORMAT_16BIT_565_RGB_3     3
  62 /* Outputs 000000rrrrrrggggggbbbbbb */
  63 # define DPI_FORMAT_18BIT_666_RGB_1     4
  64 /* Outputs 00rrrrrr00gggggg00bbbbbb */
  65 # define DPI_FORMAT_18BIT_666_RGB_2     5
  66 /* Outputs rrrrrrrrggggggggbbbbbbbb */
  67 # define DPI_FORMAT_24BIT_888_RGB       6
  68
  69 /* Reverses the polarity of the corresponding signal */
  70 # define DPI_PIXEL_CLK_INVERT           BIT(10)
  71 # define DPI_HSYNC_INVERT               BIT(9)
  72 # define DPI_VSYNC_INVERT               BIT(8)
  73 # define DPI_OUTPUT_ENABLE_INVERT       BIT(7)
  74
  75 /* Outputs the signal the falling clock edge instead of rising. */
  76 # define DPI_HSYNC_NEGATE               BIT(6)
  77 # define DPI_VSYNC_NEGATE               BIT(5)
  78 # define DPI_OUTPUT_ENABLE_NEGATE       BIT(4)
  79
  80 /* Disables the signal */
  81 # define DPI_HSYNC_DISABLE              BIT(3)
  82 # define DPI_VSYNC_DISABLE              BIT(2)
  83 # define DPI_OUTPUT_ENABLE_DISABLE      BIT(1)
  84
  85 /* Power gate to the device, full reset at 0 -> 1 transition */
  86 # define DPI_ENABLE                     BIT(0)
  87
  88 /* All other registers besides DPI_C return the ID */
  89 #define DPI_ID                  0x04
  90 # define DPI_ID_VALUE           0x00647069
  91
  92 /* General DPI hardware state. */
  93 struct vc4_dpi {
  94         struct platform_device *pdev;
  95
  96         struct drm_encoder *encoder;
  97         struct drm_connector *connector;
  98         struct drm_panel *panel;
  99
 100         void __iomem *regs;
 101
 102         struct clk *pixel_clock;
 103         struct clk *core_clock;
 104 };
 105
 106 #define DPI_READ(offset) readl(dpi->regs + (offset))
 107 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
 108
 109 /* VC4 DPI encoder KMS struct */
 110 struct vc4_dpi_encoder {
 111         struct vc4_encoder base;
 112         struct vc4_dpi *dpi;
 113 };
 114
 115 static inline struct vc4_dpi_encoder *
 116 to_vc4_dpi_encoder(struct drm_encoder *encoder)
 117 {
 118         return container_of(encoder, struct vc4_dpi_encoder, base.base);
 119 }
 120
 121 /* VC4 DPI connector KMS struct */
 122 struct vc4_dpi_connector {
 123         struct drm_connector base;
 124         struct vc4_dpi *dpi;
 125
 126         /* Since the connector is attached to just the one encoder,
 127          * this is the reference to it so we can do the best_encoder()
 128          * hook.
 129          */
 130         struct drm_encoder *encoder;
 131 };
 132
 133 static inline struct vc4_dpi_connector *
 134 to_vc4_dpi_connector(struct drm_connector *connector)
 135 {
 136         return container_of(connector, struct vc4_dpi_connector, base);
 137 }
 138
 139 #define DPI_REG(reg) { reg, #reg }
 140 static const struct {
 141         u32 reg;
 142         const char *name;
 143 } dpi_regs[] = {
 144         DPI_REG(DPI_C),
 145         DPI_REG(DPI_ID),
 146 };
 147
 148 #ifdef CONFIG_DEBUG_FS
 149 int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
 150 {
 151         struct drm_info_node *node = (struct drm_info_node *)m->private;
 152         struct drm_device *dev = node->minor->dev;
 153         struct vc4_dev *vc4 = to_vc4_dev(dev);
 154         struct vc4_dpi *dpi = vc4->dpi;
 155         int i;
 156
 157         if (!dpi)
 158                 return 0;
 159
 160         for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
 161                 seq_printf(m, "%s (0x%04x): 0x%08x\n",
 162                            dpi_regs[i].name, dpi_regs[i].reg,
 163                            DPI_READ(dpi_regs[i].reg));
 164         }
 165
 166         return 0;
 167 }
 168 #endif
 169
 170 static enum drm_connector_status
 171 vc4_dpi_connector_detect(struct drm_connector *connector, bool force)
 172 {
 173         struct vc4_dpi_connector *vc4_connector =
 174                 to_vc4_dpi_connector(connector);
 175         struct vc4_dpi *dpi = vc4_connector->dpi;
 176
 177         if (dpi->panel)
 178                 return connector_status_connected;
 179         else
 180                 return connector_status_disconnected;
 181 }
 182
 183 static void vc4_dpi_connector_destroy(struct drm_connector *connector)
 184 {
 185         drm_connector_unregister(connector);
 186         drm_connector_cleanup(connector);
 187 }
 188
 189 static int vc4_dpi_connector_get_modes(struct drm_connector *connector)
 190 {
 191         struct vc4_dpi_connector *vc4_connector =
 192                 to_vc4_dpi_connector(connector);
 193         struct vc4_dpi *dpi = vc4_connector->dpi;
 194
 195         if (dpi->panel)
 196                 return drm_panel_get_modes(dpi->panel);
 197
 198         return 0;
 199 }
 200
 201 static const struct drm_connector_funcs vc4_dpi_connector_funcs = {
 202         .dpms = drm_atomic_helper_connector_dpms,
 203         .detect = vc4_dpi_connector_detect,
 204         .fill_modes = drm_helper_probe_single_connector_modes,
 205         .destroy = vc4_dpi_connector_destroy,
 206         .reset = drm_atomic_helper_connector_reset,
 207         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 208         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 209 };
 210
 211 static const struct drm_connector_helper_funcs vc4_dpi_connector_helper_funcs = {
 212         .get_modes = vc4_dpi_connector_get_modes,
 213 };
 214
 215 static struct drm_connector *vc4_dpi_connector_init(struct drm_device *dev,
 216                                                     struct vc4_dpi *dpi)
 217 {
 218         struct drm_connector *connector = NULL;
 219         struct vc4_dpi_connector *dpi_connector;
 220
 221         dpi_connector = devm_kzalloc(dev->dev, sizeof(*dpi_connector),
 222                                      GFP_KERNEL);
 223         if (!dpi_connector)
 224                 return ERR_PTR(-ENOMEM);
 225
 226         connector = &dpi_connector->base;
 227
 228         dpi_connector->encoder = dpi->encoder;
 229         dpi_connector->dpi = dpi;
 230
 231         drm_connector_init(dev, connector, &vc4_dpi_connector_funcs,
 232                            DRM_MODE_CONNECTOR_DPI);
 233         drm_connector_helper_add(connector, &vc4_dpi_connector_helper_funcs);
 234
 235         connector->polled = 0;
 236         connector->interlace_allowed = 0;
 237         connector->doublescan_allowed = 0;
 238
 239         drm_mode_connector_attach_encoder(connector, dpi->encoder);
 240
 241         return connector;
 242 }
 243
 244 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 245         .destroy = drm_encoder_cleanup,
 246 };
 247
 248 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 249 {
 250         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 251         struct vc4_dpi *dpi = vc4_encoder->dpi;
 252
 253         drm_panel_disable(dpi->panel);
 254
 255         clk_disable_unprepare(dpi->pixel_clock);
 256
 257         drm_panel_unprepare(dpi->panel);
 258 }
 259
 260 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 261 {
 262         struct drm_display_mode *mode = &encoder->crtc->mode;
 263         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 264         struct vc4_dpi *dpi = vc4_encoder->dpi;
 265         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
 266         int ret;
 267
 268         ret = drm_panel_prepare(dpi->panel);
 269         if (ret) {
 270                 DRM_ERROR("Panel failed to prepare\n");
 271                 return;
 272         }
 273
 274         if (dpi->connector->display_info.num_bus_formats) {
 275                 u32 bus_format = dpi->connector->display_info.bus_formats[0];
 276
 277                 switch (bus_format) {
 278                 case MEDIA_BUS_FMT_RGB888_1X24:
 279                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 280                                                DPI_FORMAT);
 281                         break;
 282                 case MEDIA_BUS_FMT_BGR888_1X24:
 283                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 284                                                DPI_FORMAT);
 285                         dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 286                         break;
 287                 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 288                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 289                                                DPI_FORMAT);
 290                         break;
 291                 case MEDIA_BUS_FMT_RGB666_1X18:
 292                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 293                                                DPI_FORMAT);
 294                         break;
 295                 case MEDIA_BUS_FMT_RGB565_1X16:
 296                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 297                                                DPI_FORMAT);
 298                         break;
 299                 default:
 300                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
 301                         break;
 302                 }
 303         }
 304
 305         if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 306                 dpi_c |= DPI_HSYNC_INVERT;
 307         else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 308                 dpi_c |= DPI_HSYNC_DISABLE;
 309
 310         if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 311                 dpi_c |= DPI_VSYNC_INVERT;
 312         else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 313                 dpi_c |= DPI_VSYNC_DISABLE;
 314
 315         DPI_WRITE(DPI_C, dpi_c);
 316
 317         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 318         if (ret)
 319                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 320
 321         ret = clk_prepare_enable(dpi->pixel_clock);
 322         if (ret)
 323                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 324
 325         ret = drm_panel_enable(dpi->panel);
 326         if (ret) {
 327                 DRM_ERROR("Panel failed to enable\n");
 328                 drm_panel_unprepare(dpi->panel);
 329                 return;
 330         }
 331 }
 332
 333 static bool vc4_dpi_encoder_mode_fixup(struct drm_encoder *encoder,
 334                                        const struct drm_display_mode *mode,
 335                                        struct drm_display_mode *adjusted_mode)
 336 {
 337         if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
 338                 return false;
 339
 340         return true;
 341 }
 342
 343 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 344         .disable = vc4_dpi_encoder_disable,
 345         .enable = vc4_dpi_encoder_enable,
 346         .mode_fixup = vc4_dpi_encoder_mode_fixup,
 347 };
 348
 349 static const struct of_device_id vc4_dpi_dt_match[] = {
 350         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 351         {}
 352 };
 353
 354 /* Walks the OF graph to find the panel node and then asks DRM to look
 355  * up the panel.
 356  */
 357 static struct drm_panel *vc4_dpi_get_panel(struct device *dev)
 358 {
 359         struct device_node *endpoint, *panel_node;
 360         struct device_node *np = dev->of_node;
 361         struct drm_panel *panel;
 362
 363         endpoint = of_graph_get_next_endpoint(np, NULL);
 364         if (!endpoint) {
 365                 dev_err(dev, "no endpoint to fetch DPI panel\n");
 366                 return NULL;
 367         }
 368
 369         /* don't proceed if we have an endpoint but no panel_node tied to it */
 370         panel_node = of_graph_get_remote_port_parent(endpoint);
 371         of_node_put(endpoint);
 372         if (!panel_node) {
 373                 dev_err(dev, "no valid panel node\n");
 374                 return NULL;
 375         }
 376
 377         panel = of_drm_find_panel(panel_node);
 378         of_node_put(panel_node);
 379
 380         return panel;
 381 }
 382
 383 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 384 {
 385         struct platform_device *pdev = to_platform_device(dev);
 386         struct drm_device *drm = dev_get_drvdata(master);
 387         struct vc4_dev *vc4 = to_vc4_dev(drm);
 388         struct vc4_dpi *dpi;
 389         struct vc4_dpi_encoder *vc4_dpi_encoder;
 390         int ret;
 391
 392         dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
 393         if (!dpi)
 394                 return -ENOMEM;
 395
 396         vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
 397                                        GFP_KERNEL);
 398         if (!vc4_dpi_encoder)
 399                 return -ENOMEM;
 400         vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
 401         vc4_dpi_encoder->dpi = dpi;
 402         dpi->encoder = &vc4_dpi_encoder->base.base;
 403
 404         dpi->pdev = pdev;
 405         dpi->regs = vc4_ioremap_regs(pdev, 0);
 406         if (IS_ERR(dpi->regs))
 407                 return PTR_ERR(dpi->regs);
 408
 409         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 410                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 411                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 412                 return -ENODEV;
 413         }
 414
 415         dpi->core_clock = devm_clk_get(dev, "core");
 416         if (IS_ERR(dpi->core_clock)) {
 417                 ret = PTR_ERR(dpi->core_clock);
 418                 if (ret != -EPROBE_DEFER)
 419                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 420                 return ret;
 421         }
 422         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 423         if (IS_ERR(dpi->pixel_clock)) {
 424                 ret = PTR_ERR(dpi->pixel_clock);
 425                 if (ret != -EPROBE_DEFER)
 426                         DRM_ERROR("Failed to get pixel clock: %d\n", ret);
 427                 return ret;
 428         }
 429
 430         ret = clk_prepare_enable(dpi->core_clock);
 431         if (ret)
 432                 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
 433
 434         dpi->panel = vc4_dpi_get_panel(dev);
 435
 436         drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
 437                          DRM_MODE_ENCODER_DPI, NULL);
 438         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 439
 440         dpi->connector = vc4_dpi_connector_init(drm, dpi);
 441         if (IS_ERR(dpi->connector)) {
 442                 ret = PTR_ERR(dpi->connector);
 443                 goto err_destroy_encoder;
 444         }
 445
 446         if (dpi->panel)
 447                 drm_panel_attach(dpi->panel, dpi->connector);
 448
 449         dev_set_drvdata(dev, dpi);
 450
 451         vc4->dpi = dpi;
 452
 453         return 0;
 454
 455 err_destroy_encoder:
 456         drm_encoder_cleanup(dpi->encoder);
 457         clk_disable_unprepare(dpi->core_clock);
 458         return ret;
 459 }
 460
 461 static void vc4_dpi_unbind(struct device *dev, struct device *master,
 462                            void *data)
 463 {
 464         struct drm_device *drm = dev_get_drvdata(master);
 465         struct vc4_dev *vc4 = to_vc4_dev(drm);
 466         struct vc4_dpi *dpi = dev_get_drvdata(dev);
 467
 468         if (dpi->panel)
 469                 drm_panel_detach(dpi->panel);
 470
 471         vc4_dpi_connector_destroy(dpi->connector);
 472         drm_encoder_cleanup(dpi->encoder);
 473
 474         clk_disable_unprepare(dpi->core_clock);
 475
 476         vc4->dpi = NULL;
 477 }
 478
 479 static const struct component_ops vc4_dpi_ops = {
 480         .bind   = vc4_dpi_bind,
 481         .unbind = vc4_dpi_unbind,
 482 };
 483
 484 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 485 {
 486         return component_add(&pdev->dev, &vc4_dpi_ops);
 487 }
 488
 489 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 490 {
 491         component_del(&pdev->dev, &vc4_dpi_ops);
 492         return 0;
 493 }
 494
 495 struct platform_driver vc4_dpi_driver = {
 496         .probe = vc4_dpi_dev_probe,
 497         .remove = vc4_dpi_dev_remove,
 498         .driver = {
 499                 .name = "vc4_dpi",
 500                 .of_match_table = vc4_dpi_dt_match,
 501         },
 502 };