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