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 static void vc4_dpi_dump_regs(struct vc4_dpi *dpi)
 148 {
 149         int i;
 150
 151         for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
 152                 DRM_INFO("0x%04x (%s): 0x%08x\n",
 153                          dpi_regs[i].reg, dpi_regs[i].name,
 154                          DPI_READ(dpi_regs[i].reg));
 155         }
 156 }
 157
 158 #ifdef CONFIG_DEBUG_FS
 159 int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
 160 {
 161         struct drm_info_node *node = (struct drm_info_node *)m->private;
 162         struct drm_device *dev = node->minor->dev;
 163         struct vc4_dev *vc4 = to_vc4_dev(dev);
 164         struct vc4_dpi *dpi = vc4->dpi;
 165         int i;
 166
 167         if (!dpi)
 168                 return 0;
 169
 170         for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
 171                 seq_printf(m, "%s (0x%04x): 0x%08x\n",
 172                            dpi_regs[i].name, dpi_regs[i].reg,
 173                            DPI_READ(dpi_regs[i].reg));
 174         }
 175
 176         return 0;
 177 }
 178 #endif
 179
 180 static enum drm_connector_status
 181 vc4_dpi_connector_detect(struct drm_connector *connector, bool force)
 182 {
 183         struct vc4_dpi_connector *vc4_connector =
 184                 to_vc4_dpi_connector(connector);
 185         struct vc4_dpi *dpi = vc4_connector->dpi;
 186
 187         if (dpi->panel)
 188                 return connector_status_connected;
 189         else
 190                 return connector_status_disconnected;
 191 }
 192
 193 static void vc4_dpi_connector_destroy(struct drm_connector *connector)
 194 {
 195         drm_connector_unregister(connector);
 196         drm_connector_cleanup(connector);
 197 }
 198
 199 static int vc4_dpi_connector_get_modes(struct drm_connector *connector)
 200 {
 201         struct vc4_dpi_connector *vc4_connector =
 202                 to_vc4_dpi_connector(connector);
 203         struct vc4_dpi *dpi = vc4_connector->dpi;
 204
 205         if (dpi->panel)
 206                 return drm_panel_get_modes(dpi->panel);
 207
 208         return 0;
 209 }
 210
 211 static struct drm_encoder *
 212 vc4_dpi_connector_best_encoder(struct drm_connector *connector)
 213 {
 214         struct vc4_dpi_connector *dpi_connector =
 215                 to_vc4_dpi_connector(connector);
 216         return dpi_connector->encoder;
 217 }
 218
 219 static const struct drm_connector_funcs vc4_dpi_connector_funcs = {
 220         .dpms = drm_atomic_helper_connector_dpms,
 221         .detect = vc4_dpi_connector_detect,
 222         .fill_modes = drm_helper_probe_single_connector_modes,
 223         .destroy = vc4_dpi_connector_destroy,
 224         .reset = drm_atomic_helper_connector_reset,
 225         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 226         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 227 };
 228
 229 static const struct drm_connector_helper_funcs vc4_dpi_connector_helper_funcs = {
 230         .get_modes = vc4_dpi_connector_get_modes,
 231         .best_encoder = vc4_dpi_connector_best_encoder,
 232 };
 233
 234 static struct drm_connector *vc4_dpi_connector_init(struct drm_device *dev,
 235                                                     struct vc4_dpi *dpi)
 236 {
 237         struct drm_connector *connector = NULL;
 238         struct vc4_dpi_connector *dpi_connector;
 239         int ret = 0;
 240
 241         dpi_connector = devm_kzalloc(dev->dev, sizeof(*dpi_connector),
 242                                      GFP_KERNEL);
 243         if (!dpi_connector) {
 244                 ret = -ENOMEM;
 245                 goto fail;
 246         }
 247         connector = &dpi_connector->base;
 248
 249         dpi_connector->encoder = dpi->encoder;
 250         dpi_connector->dpi = dpi;
 251
 252         drm_connector_init(dev, connector, &vc4_dpi_connector_funcs,
 253                            DRM_MODE_CONNECTOR_DPI);
 254         drm_connector_helper_add(connector, &vc4_dpi_connector_helper_funcs);
 255
 256         connector->polled = 0;
 257         connector->interlace_allowed = 0;
 258         connector->doublescan_allowed = 0;
 259
 260         drm_mode_connector_attach_encoder(connector, dpi->encoder);
 261
 262         return connector;
 263
 264  fail:
 265         if (connector)
 266                 vc4_dpi_connector_destroy(connector);
 267
 268         return ERR_PTR(ret);
 269 }
 270
 271 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 272         .destroy = drm_encoder_cleanup,
 273 };
 274
 275 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 276 {
 277         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 278         struct vc4_dpi *dpi = vc4_encoder->dpi;
 279
 280         drm_panel_disable(dpi->panel);
 281
 282         clk_disable_unprepare(dpi->pixel_clock);
 283
 284         drm_panel_unprepare(dpi->panel);
 285 }
 286
 287 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 288 {
 289         struct drm_display_mode *mode = &encoder->crtc->mode;
 290         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 291         struct vc4_dpi *dpi = vc4_encoder->dpi;
 292         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
 293         int ret;
 294
 295         ret = drm_panel_prepare(dpi->panel);
 296         if (ret) {
 297                 DRM_ERROR("Panel failed to prepare\n");
 298                 return;
 299         }
 300
 301         if (dpi->connector->display_info.num_bus_formats) {
 302                 u32 bus_format = dpi->connector->display_info.bus_formats[0];
 303
 304                 switch (bus_format) {
 305                 case MEDIA_BUS_FMT_RGB888_1X24:
 306                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 307                                                DPI_FORMAT);
 308                         break;
 309                 case MEDIA_BUS_FMT_BGR888_1X24:
 310                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 311                                                DPI_FORMAT);
 312                         dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 313                         break;
 314                 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 315                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 316                                                DPI_FORMAT);
 317                         break;
 318                 case MEDIA_BUS_FMT_RGB666_1X18:
 319                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 320                                                DPI_FORMAT);
 321                         break;
 322                 case MEDIA_BUS_FMT_RGB565_1X16:
 323                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 324                                                DPI_FORMAT);
 325                         break;
 326                 default:
 327                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
 328                         break;
 329                 }
 330         }
 331
 332         if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 333                 dpi_c |= DPI_HSYNC_INVERT;
 334         else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 335                 dpi_c |= DPI_HSYNC_DISABLE;
 336
 337         if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 338                 dpi_c |= DPI_VSYNC_INVERT;
 339         else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 340                 dpi_c |= DPI_VSYNC_DISABLE;
 341
 342         DPI_WRITE(DPI_C, dpi_c);
 343
 344         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 345         if (ret)
 346                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 347
 348         ret = clk_prepare_enable(dpi->pixel_clock);
 349         if (ret)
 350                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 351
 352         ret = drm_panel_enable(dpi->panel);
 353         if (ret) {
 354                 DRM_ERROR("Panel failed to enable\n");
 355                 drm_panel_unprepare(dpi->panel);
 356                 return;
 357         }
 358 }
 359
 360 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 361         .disable = vc4_dpi_encoder_disable,
 362         .enable = vc4_dpi_encoder_enable,
 363 };
 364
 365 static const struct of_device_id vc4_dpi_dt_match[] = {
 366         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 367         {}
 368 };
 369
 370 /* Walks the OF graph to find the panel node and then asks DRM to look
 371  * up the panel.
 372  */
 373 static struct drm_panel *vc4_dpi_get_panel(struct device *dev)
 374 {
 375         struct device_node *endpoint, *panel_node;
 376         struct device_node *np = dev->of_node;
 377         struct drm_panel *panel;
 378
 379         endpoint = of_graph_get_next_endpoint(np, NULL);
 380         if (!endpoint) {
 381                 dev_err(dev, "no endpoint to fetch DPI panel\n");
 382                 return NULL;
 383         }
 384
 385         /* don't proceed if we have an endpoint but no panel_node tied to it */
 386         panel_node = of_graph_get_remote_port_parent(endpoint);
 387         of_node_put(endpoint);
 388         if (!panel_node) {
 389                 dev_err(dev, "no valid panel node\n");
 390                 return NULL;
 391         }
 392
 393         panel = of_drm_find_panel(panel_node);
 394         of_node_put(panel_node);
 395
 396         return panel;
 397 }
 398
 399 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 400 {
 401         struct platform_device *pdev = to_platform_device(dev);
 402         struct drm_device *drm = dev_get_drvdata(master);
 403         struct vc4_dev *vc4 = to_vc4_dev(drm);
 404         struct vc4_dpi *dpi;
 405         struct vc4_dpi_encoder *vc4_dpi_encoder;
 406         int ret;
 407
 408         dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
 409         if (!dpi)
 410                 return -ENOMEM;
 411
 412         vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
 413                                        GFP_KERNEL);
 414         if (!vc4_dpi_encoder)
 415                 return -ENOMEM;
 416         vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
 417         vc4_dpi_encoder->dpi = dpi;
 418         dpi->encoder = &vc4_dpi_encoder->base.base;
 419
 420         dpi->pdev = pdev;
 421         dpi->regs = vc4_ioremap_regs(pdev, 0);
 422         if (IS_ERR(dpi->regs))
 423                 return PTR_ERR(dpi->regs);
 424
 425         vc4_dpi_dump_regs(dpi);
 426
 427         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 428                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 429                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 430                 return -ENODEV;
 431         }
 432
 433         dpi->core_clock = devm_clk_get(dev, "core");
 434         if (IS_ERR(dpi->core_clock)) {
 435                 ret = PTR_ERR(dpi->core_clock);
 436                 if (ret != -EPROBE_DEFER)
 437                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 438                 return ret;
 439         }
 440         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 441         if (IS_ERR(dpi->pixel_clock)) {
 442                 ret = PTR_ERR(dpi->pixel_clock);
 443                 if (ret != -EPROBE_DEFER)
 444                         DRM_ERROR("Failed to get pixel clock: %d\n", ret);
 445                 return ret;
 446         }
 447
 448         ret = clk_prepare_enable(dpi->core_clock);
 449         if (ret)
 450                 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
 451
 452         dpi->panel = vc4_dpi_get_panel(dev);
 453
 454         drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
 455                          DRM_MODE_ENCODER_DPI, NULL);
 456         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 457
 458         dpi->connector = vc4_dpi_connector_init(drm, dpi);
 459         if (IS_ERR(dpi->connector)) {
 460                 ret = PTR_ERR(dpi->connector);
 461                 goto err_destroy_encoder;
 462         }
 463
 464         if (dpi->panel)
 465                 drm_panel_attach(dpi->panel, dpi->connector);
 466
 467         dev_set_drvdata(dev, dpi);
 468
 469         vc4->dpi = dpi;
 470
 471         return 0;
 472
 473 err_destroy_encoder:
 474         drm_encoder_cleanup(dpi->encoder);
 475         clk_disable_unprepare(dpi->core_clock);
 476         return ret;
 477 }
 478
 479 static void vc4_dpi_unbind(struct device *dev, struct device *master,
 480                            void *data)
 481 {
 482         struct drm_device *drm = dev_get_drvdata(master);
 483         struct vc4_dev *vc4 = to_vc4_dev(drm);
 484         struct vc4_dpi *dpi = dev_get_drvdata(dev);
 485
 486         if (dpi->panel)
 487                 drm_panel_detach(dpi->panel);
 488
 489         vc4_dpi_connector_destroy(dpi->connector);
 490         drm_encoder_cleanup(dpi->encoder);
 491
 492         clk_disable_unprepare(dpi->core_clock);
 493
 494         vc4->dpi = NULL;
 495 }
 496
 497 static const struct component_ops vc4_dpi_ops = {
 498         .bind   = vc4_dpi_bind,
 499         .unbind = vc4_dpi_unbind,
 500 };
 501
 502 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 503 {
 504         return component_add(&pdev->dev, &vc4_dpi_ops);
 505 }
 506
 507 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 508 {
 509         component_del(&pdev->dev, &vc4_dpi_ops);
 510         return 0;
 511 }
 512
 513 struct platform_driver vc4_dpi_driver = {
 514         .probe = vc4_dpi_dev_probe,
 515         .remove = vc4_dpi_dev_remove,
 516         .driver = {
 517                 .name = "vc4_dpi",
 518                 .of_match_table = vc4_dpi_dt_match,
 519         },
 520 };