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 const struct drm_connector_funcs vc4_dpi_connector_funcs = {
 212         .dpms = drm_atomic_helper_connector_dpms,
 213         .detect = vc4_dpi_connector_detect,
 214         .fill_modes = drm_helper_probe_single_connector_modes,
 215         .destroy = vc4_dpi_connector_destroy,
 216         .reset = drm_atomic_helper_connector_reset,
 217         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 218         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 219 };
 220
 221 static const struct drm_connector_helper_funcs vc4_dpi_connector_helper_funcs = {
 222         .get_modes = vc4_dpi_connector_get_modes,
 223 };
 224
 225 static struct drm_connector *vc4_dpi_connector_init(struct drm_device *dev,
 226                                                     struct vc4_dpi *dpi)
 227 {
 228         struct drm_connector *connector = NULL;
 229         struct vc4_dpi_connector *dpi_connector;
 230
 231         dpi_connector = devm_kzalloc(dev->dev, sizeof(*dpi_connector),
 232                                      GFP_KERNEL);
 233         if (!dpi_connector)
 234                 return ERR_PTR(-ENOMEM);
 235
 236         connector = &dpi_connector->base;
 237
 238         dpi_connector->encoder = dpi->encoder;
 239         dpi_connector->dpi = dpi;
 240
 241         drm_connector_init(dev, connector, &vc4_dpi_connector_funcs,
 242                            DRM_MODE_CONNECTOR_DPI);
 243         drm_connector_helper_add(connector, &vc4_dpi_connector_helper_funcs);
 244
 245         connector->polled = 0;
 246         connector->interlace_allowed = 0;
 247         connector->doublescan_allowed = 0;
 248
 249         drm_mode_connector_attach_encoder(connector, dpi->encoder);
 250
 251         return connector;
 252 }
 253
 254 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 255         .destroy = drm_encoder_cleanup,
 256 };
 257
 258 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 259 {
 260         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 261         struct vc4_dpi *dpi = vc4_encoder->dpi;
 262
 263         drm_panel_disable(dpi->panel);
 264
 265         clk_disable_unprepare(dpi->pixel_clock);
 266
 267         drm_panel_unprepare(dpi->panel);
 268 }
 269
 270 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 271 {
 272         struct drm_display_mode *mode = &encoder->crtc->mode;
 273         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 274         struct vc4_dpi *dpi = vc4_encoder->dpi;
 275         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
 276         int ret;
 277
 278         ret = drm_panel_prepare(dpi->panel);
 279         if (ret) {
 280                 DRM_ERROR("Panel failed to prepare\n");
 281                 return;
 282         }
 283
 284         if (dpi->connector->display_info.num_bus_formats) {
 285                 u32 bus_format = dpi->connector->display_info.bus_formats[0];
 286
 287                 switch (bus_format) {
 288                 case MEDIA_BUS_FMT_RGB888_1X24:
 289                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 290                                                DPI_FORMAT);
 291                         break;
 292                 case MEDIA_BUS_FMT_BGR888_1X24:
 293                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 294                                                DPI_FORMAT);
 295                         dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 296                         break;
 297                 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 298                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 299                                                DPI_FORMAT);
 300                         break;
 301                 case MEDIA_BUS_FMT_RGB666_1X18:
 302                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 303                                                DPI_FORMAT);
 304                         break;
 305                 case MEDIA_BUS_FMT_RGB565_1X16:
 306                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 307                                                DPI_FORMAT);
 308                         break;
 309                 default:
 310                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
 311                         break;
 312                 }
 313         }
 314
 315         if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 316                 dpi_c |= DPI_HSYNC_INVERT;
 317         else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 318                 dpi_c |= DPI_HSYNC_DISABLE;
 319
 320         if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 321                 dpi_c |= DPI_VSYNC_INVERT;
 322         else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 323                 dpi_c |= DPI_VSYNC_DISABLE;
 324
 325         DPI_WRITE(DPI_C, dpi_c);
 326
 327         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 328         if (ret)
 329                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 330
 331         ret = clk_prepare_enable(dpi->pixel_clock);
 332         if (ret)
 333                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 334
 335         ret = drm_panel_enable(dpi->panel);
 336         if (ret) {
 337                 DRM_ERROR("Panel failed to enable\n");
 338                 drm_panel_unprepare(dpi->panel);
 339                 return;
 340         }
 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 };
 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         vc4_dpi_dump_regs(dpi);
 409
 410         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 411                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 412                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 413                 return -ENODEV;
 414         }
 415
 416         dpi->core_clock = devm_clk_get(dev, "core");
 417         if (IS_ERR(dpi->core_clock)) {
 418                 ret = PTR_ERR(dpi->core_clock);
 419                 if (ret != -EPROBE_DEFER)
 420                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 421                 return ret;
 422         }
 423         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 424         if (IS_ERR(dpi->pixel_clock)) {
 425                 ret = PTR_ERR(dpi->pixel_clock);
 426                 if (ret != -EPROBE_DEFER)
 427                         DRM_ERROR("Failed to get pixel clock: %d\n", ret);
 428                 return ret;
 429         }
 430
 431         ret = clk_prepare_enable(dpi->core_clock);
 432         if (ret)
 433                 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
 434
 435         dpi->panel = vc4_dpi_get_panel(dev);
 436
 437         drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
 438                          DRM_MODE_ENCODER_DPI, NULL);
 439         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 440
 441         dpi->connector = vc4_dpi_connector_init(drm, dpi);
 442         if (IS_ERR(dpi->connector)) {
 443                 ret = PTR_ERR(dpi->connector);
 444                 goto err_destroy_encoder;
 445         }
 446
 447         if (dpi->panel)
 448                 drm_panel_attach(dpi->panel, dpi->connector);
 449
 450         dev_set_drvdata(dev, dpi);
 451
 452         vc4->dpi = dpi;
 453
 454         return 0;
 455
 456 err_destroy_encoder:
 457         drm_encoder_cleanup(dpi->encoder);
 458         clk_disable_unprepare(dpi->core_clock);
 459         return ret;
 460 }
 461
 462 static void vc4_dpi_unbind(struct device *dev, struct device *master,
 463                            void *data)
 464 {
 465         struct drm_device *drm = dev_get_drvdata(master);
 466         struct vc4_dev *vc4 = to_vc4_dev(drm);
 467         struct vc4_dpi *dpi = dev_get_drvdata(dev);
 468
 469         if (dpi->panel)
 470                 drm_panel_detach(dpi->panel);
 471
 472         vc4_dpi_connector_destroy(dpi->connector);
 473         drm_encoder_cleanup(dpi->encoder);
 474
 475         clk_disable_unprepare(dpi->core_clock);
 476
 477         vc4->dpi = NULL;
 478 }
 479
 480 static const struct component_ops vc4_dpi_ops = {
 481         .bind   = vc4_dpi_bind,
 482         .unbind = vc4_dpi_unbind,
 483 };
 484
 485 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 486 {
 487         return component_add(&pdev->dev, &vc4_dpi_ops);
 488 }
 489
 490 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 491 {
 492         component_del(&pdev->dev, &vc4_dpi_ops);
 493         return 0;
 494 }
 495
 496 struct platform_driver vc4_dpi_driver = {
 497         .probe = vc4_dpi_dev_probe,
 498         .remove = vc4_dpi_dev_remove,
 499         .driver = {
 500                 .name = "vc4_dpi",
 501                 .of_match_table = vc4_dpi_dt_match,
 502         },
 503 };