drivers/gpu/drm/vc4/vc4_dpi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2016 Broadcom Limited
   4  */
   5
   6 /**
   7  * DOC: VC4 DPI module
   8  *
   9  * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI
  10  * signals.  On BCM2835, these can be routed out to GPIO0-27 with the
  11  * ALT2 function.
  12  */
  13
  14 #include <drm/drm_atomic_helper.h>
  15 #include <drm/drm_bridge.h>
  16 #include <drm/drm_edid.h>
  17 #include <drm/drm_of.h>
  18 #include <drm/drm_panel.h>
  19 #include <drm/drm_probe_helper.h>
  20 #include <drm/drm_simple_kms_helper.h>
  21 #include <linux/clk.h>
  22 #include <linux/component.h>
  23 #include <linux/media-bus-format.h>
  24 #include <linux/of_graph.h>
  25 #include <linux/of_platform.h>
  26 #include "vc4_drv.h"
  27 #include "vc4_regs.h"
  28
  29 #define DPI_C                   0x00
  30 # define DPI_OUTPUT_ENABLE_MODE         BIT(16)
  31
  32 /* The order field takes the incoming 24 bit RGB from the pixel valve
  33  * and shuffles the 3 channels.
  34  */
  35 # define DPI_ORDER_MASK                 VC4_MASK(15, 14)
  36 # define DPI_ORDER_SHIFT                14
  37 # define DPI_ORDER_RGB                  0
  38 # define DPI_ORDER_BGR                  1
  39 # define DPI_ORDER_GRB                  2
  40 # define DPI_ORDER_BRG                  3
  41
  42 /* The format field takes the ORDER-shuffled pixel valve data and
  43  * formats it onto the output lines.
  44  */
  45 # define DPI_FORMAT_MASK                VC4_MASK(13, 11)
  46 # define DPI_FORMAT_SHIFT               11
  47 /* This define is named in the hardware, but actually just outputs 0. */
  48 # define DPI_FORMAT_9BIT_666_RGB        0
  49 /* Outputs 00000000rrrrrggggggbbbbb */
  50 # define DPI_FORMAT_16BIT_565_RGB_1     1
  51 /* Outputs 000rrrrr00gggggg000bbbbb */
  52 # define DPI_FORMAT_16BIT_565_RGB_2     2
  53 /* Outputs 00rrrrr000gggggg00bbbbb0 */
  54 # define DPI_FORMAT_16BIT_565_RGB_3     3
  55 /* Outputs 000000rrrrrrggggggbbbbbb */
  56 # define DPI_FORMAT_18BIT_666_RGB_1     4
  57 /* Outputs 00rrrrrr00gggggg00bbbbbb */
  58 # define DPI_FORMAT_18BIT_666_RGB_2     5
  59 /* Outputs rrrrrrrrggggggggbbbbbbbb */
  60 # define DPI_FORMAT_24BIT_888_RGB       6
  61
  62 /* Reverses the polarity of the corresponding signal */
  63 # define DPI_PIXEL_CLK_INVERT           BIT(10)
  64 # define DPI_HSYNC_INVERT               BIT(9)
  65 # define DPI_VSYNC_INVERT               BIT(8)
  66 # define DPI_OUTPUT_ENABLE_INVERT       BIT(7)
  67
  68 /* Outputs the signal the falling clock edge instead of rising. */
  69 # define DPI_HSYNC_NEGATE               BIT(6)
  70 # define DPI_VSYNC_NEGATE               BIT(5)
  71 # define DPI_OUTPUT_ENABLE_NEGATE       BIT(4)
  72
  73 /* Disables the signal */
  74 # define DPI_HSYNC_DISABLE              BIT(3)
  75 # define DPI_VSYNC_DISABLE              BIT(2)
  76 # define DPI_OUTPUT_ENABLE_DISABLE      BIT(1)
  77
  78 /* Power gate to the device, full reset at 0 -> 1 transition */
  79 # define DPI_ENABLE                     BIT(0)
  80
  81 /* All other registers besides DPI_C return the ID */
  82 #define DPI_ID                  0x04
  83 # define DPI_ID_VALUE           0x00647069
  84
  85 /* General DPI hardware state. */
  86 struct vc4_dpi {
  87         struct platform_device *pdev;
  88
  89         struct drm_encoder *encoder;
  90
  91         void __iomem *regs;
  92
  93         struct clk *pixel_clock;
  94         struct clk *core_clock;
  95
  96         struct debugfs_regset32 regset;
  97 };
  98
  99 #define DPI_READ(offset) readl(dpi->regs + (offset))
 100 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
 101
 102 /* VC4 DPI encoder KMS struct */
 103 struct vc4_dpi_encoder {
 104         struct vc4_encoder base;
 105         struct vc4_dpi *dpi;
 106 };
 107
 108 static inline struct vc4_dpi_encoder *
 109 to_vc4_dpi_encoder(struct drm_encoder *encoder)
 110 {
 111         return container_of(encoder, struct vc4_dpi_encoder, base.base);
 112 }
 113
 114 static const struct debugfs_reg32 dpi_regs[] = {
 115         VC4_REG32(DPI_C),
 116         VC4_REG32(DPI_ID),
 117 };
 118
 119 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 120 {
 121         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 122         struct vc4_dpi *dpi = vc4_encoder->dpi;
 123
 124         clk_disable_unprepare(dpi->pixel_clock);
 125 }
 126
 127 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 128 {
 129         struct drm_device *dev = encoder->dev;
 130         struct drm_display_mode *mode = &encoder->crtc->mode;
 131         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 132         struct vc4_dpi *dpi = vc4_encoder->dpi;
 133         struct drm_connector_list_iter conn_iter;
 134         struct drm_connector *connector = NULL, *connector_scan;
 135         u32 dpi_c = DPI_ENABLE;
 136         int ret;
 137
 138         /* Look up the connector attached to DPI so we can get the
 139          * bus_format.  Ideally the bridge would tell us the
 140          * bus_format we want, but it doesn't yet, so assume that it's
 141          * uniform throughout the bridge chain.
 142          */
 143         drm_connector_list_iter_begin(dev, &conn_iter);
 144         drm_for_each_connector_iter(connector_scan, &conn_iter) {
 145                 if (connector_scan->encoder == encoder) {
 146                         connector = connector_scan;
 147                         break;
 148                 }
 149         }
 150         drm_connector_list_iter_end(&conn_iter);
 151
 152         /* Default to 24bit if no connector or format found. */
 153         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
 154
 155         if (connector) {
 156                 if (connector->display_info.num_bus_formats) {
 157                         u32 bus_format = connector->display_info.bus_formats[0];
 158
 159                         dpi_c &= ~DPI_FORMAT_MASK;
 160
 161                         switch (bus_format) {
 162                         case MEDIA_BUS_FMT_RGB888_1X24:
 163                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 164                                                        DPI_FORMAT);
 165                                 break;
 166                         case MEDIA_BUS_FMT_BGR888_1X24:
 167                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 168                                                        DPI_FORMAT);
 169                                 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR,
 170                                                        DPI_ORDER);
 171                                 break;
 172                         case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 173                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 174                                                        DPI_FORMAT);
 175                                 break;
 176                         case MEDIA_BUS_FMT_RGB666_1X18:
 177                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 178                                                        DPI_FORMAT);
 179                                 break;
 180                         case MEDIA_BUS_FMT_RGB565_1X16:
 181                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 182                                                        DPI_FORMAT);
 183                                 break;
 184                         default:
 185                                 DRM_ERROR("Unknown media bus format %d\n",
 186                                           bus_format);
 187                                 break;
 188                         }
 189                 }
 190
 191                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
 192                         dpi_c |= DPI_PIXEL_CLK_INVERT;
 193
 194                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
 195                         dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 196         }
 197
 198         if (mode->flags & DRM_MODE_FLAG_CSYNC) {
 199                 if (mode->flags & DRM_MODE_FLAG_NCSYNC)
 200                         dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 201         } else {
 202                 dpi_c |= DPI_OUTPUT_ENABLE_MODE;
 203
 204                 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 205                         dpi_c |= DPI_HSYNC_INVERT;
 206                 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 207                         dpi_c |= DPI_HSYNC_DISABLE;
 208
 209                 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 210                         dpi_c |= DPI_VSYNC_INVERT;
 211                 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 212                         dpi_c |= DPI_VSYNC_DISABLE;
 213         }
 214
 215         DPI_WRITE(DPI_C, dpi_c);
 216
 217         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 218         if (ret)
 219                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 220
 221         ret = clk_prepare_enable(dpi->pixel_clock);
 222         if (ret)
 223                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 224 }
 225
 226 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
 227                                                        const struct drm_display_mode *mode)
 228 {
 229         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 230                 return MODE_NO_INTERLACE;
 231
 232         return MODE_OK;
 233 }
 234
 235 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 236         .disable = vc4_dpi_encoder_disable,
 237         .enable = vc4_dpi_encoder_enable,
 238         .mode_valid = vc4_dpi_encoder_mode_valid,
 239 };
 240
 241 static const struct of_device_id vc4_dpi_dt_match[] = {
 242         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 243         {}
 244 };
 245
 246 /* Sets up the next link in the display chain, whether it's a panel or
 247  * a bridge.
 248  */
 249 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 250 {
 251         struct device *dev = &dpi->pdev->dev;
 252         struct drm_bridge *bridge;
 253
 254         bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
 255         if (IS_ERR(bridge)) {
 256                 /* If nothing was connected in the DT, that's not an
 257                  * error.
 258                  */
 259                 if (PTR_ERR(bridge) == -ENODEV)
 260                         return 0;
 261                 else
 262                         return PTR_ERR(bridge);
 263         }
 264
 265         return drm_bridge_attach(dpi->encoder, bridge, NULL, 0);
 266 }
 267
 268 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 269 {
 270         struct platform_device *pdev = to_platform_device(dev);
 271         struct drm_device *drm = dev_get_drvdata(master);
 272         struct vc4_dev *vc4 = to_vc4_dev(drm);
 273         struct vc4_dpi *dpi;
 274         struct vc4_dpi_encoder *vc4_dpi_encoder;
 275         int ret;
 276
 277         dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
 278         if (!dpi)
 279                 return -ENOMEM;
 280
 281         vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
 282                                        GFP_KERNEL);
 283         if (!vc4_dpi_encoder)
 284                 return -ENOMEM;
 285         vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
 286         vc4_dpi_encoder->dpi = dpi;
 287         dpi->encoder = &vc4_dpi_encoder->base.base;
 288
 289         dpi->pdev = pdev;
 290         dpi->regs = vc4_ioremap_regs(pdev, 0);
 291         if (IS_ERR(dpi->regs))
 292                 return PTR_ERR(dpi->regs);
 293         dpi->regset.base = dpi->regs;
 294         dpi->regset.regs = dpi_regs;
 295         dpi->regset.nregs = ARRAY_SIZE(dpi_regs);
 296
 297         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 298                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 299                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 300                 return -ENODEV;
 301         }
 302
 303         dpi->core_clock = devm_clk_get(dev, "core");
 304         if (IS_ERR(dpi->core_clock)) {
 305                 ret = PTR_ERR(dpi->core_clock);
 306                 if (ret != -EPROBE_DEFER)
 307                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 308                 return ret;
 309         }
 310         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 311         if (IS_ERR(dpi->pixel_clock)) {
 312                 ret = PTR_ERR(dpi->pixel_clock);
 313                 if (ret != -EPROBE_DEFER)
 314                         DRM_ERROR("Failed to get pixel clock: %d\n", ret);
 315                 return ret;
 316         }
 317
 318         ret = clk_prepare_enable(dpi->core_clock);
 319         if (ret)
 320                 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
 321
 322         drm_simple_encoder_init(drm, dpi->encoder, DRM_MODE_ENCODER_DPI);
 323         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 324
 325         ret = vc4_dpi_init_bridge(dpi);
 326         if (ret)
 327                 goto err_destroy_encoder;
 328
 329         dev_set_drvdata(dev, dpi);
 330
 331         vc4->dpi = dpi;
 332
 333         vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset);
 334
 335         return 0;
 336
 337 err_destroy_encoder:
 338         drm_encoder_cleanup(dpi->encoder);
 339         clk_disable_unprepare(dpi->core_clock);
 340         return ret;
 341 }
 342
 343 static void vc4_dpi_unbind(struct device *dev, struct device *master,
 344                            void *data)
 345 {
 346         struct drm_device *drm = dev_get_drvdata(master);
 347         struct vc4_dev *vc4 = to_vc4_dev(drm);
 348         struct vc4_dpi *dpi = dev_get_drvdata(dev);
 349
 350         drm_of_panel_bridge_remove(dev->of_node, 0, 0);
 351
 352         drm_encoder_cleanup(dpi->encoder);
 353
 354         clk_disable_unprepare(dpi->core_clock);
 355
 356         vc4->dpi = NULL;
 357 }
 358
 359 static const struct component_ops vc4_dpi_ops = {
 360         .bind   = vc4_dpi_bind,
 361         .unbind = vc4_dpi_unbind,
 362 };
 363
 364 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 365 {
 366         return component_add(&pdev->dev, &vc4_dpi_ops);
 367 }
 368
 369 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 370 {
 371         component_del(&pdev->dev, &vc4_dpi_ops);
 372         return 0;
 373 }
 374
 375 struct platform_driver vc4_dpi_driver = {
 376         .probe = vc4_dpi_dev_probe,
 377         .remove = vc4_dpi_dev_remove,
 378         .driver = {
 379                 .name = "vc4_dpi",
 380                 .of_match_table = vc4_dpi_dt_match,
 381         },
 382 };