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_drv.h>
  17 #include <drm/drm_edid.h>
  18 #include <drm/drm_of.h>
  19 #include <drm/drm_panel.h>
  20 #include <drm/drm_probe_helper.h>
  21 #include <drm/drm_simple_kms_helper.h>
  22 #include <linux/clk.h>
  23 #include <linux/component.h>
  24 #include <linux/media-bus-format.h>
  25 #include <linux/mod_devicetable.h>
  26 #include <linux/platform_device.h>
  27 #include "vc4_drv.h"
  28 #include "vc4_regs.h"
  29
  30 #define DPI_C                   0x00
  31 # define DPI_OUTPUT_ENABLE_MODE         BIT(16)
  32
  33 /* The order field takes the incoming 24 bit RGB from the pixel valve
  34  * and shuffles the 3 channels.
  35  */
  36 # define DPI_ORDER_MASK                 VC4_MASK(15, 14)
  37 # define DPI_ORDER_SHIFT                14
  38 # define DPI_ORDER_RGB                  0
  39 # define DPI_ORDER_BGR                  1
  40 # define DPI_ORDER_GRB                  2
  41 # define DPI_ORDER_BRG                  3
  42
  43 /* The format field takes the ORDER-shuffled pixel valve data and
  44  * formats it onto the output lines.
  45  */
  46 # define DPI_FORMAT_MASK                VC4_MASK(13, 11)
  47 # define DPI_FORMAT_SHIFT               11
  48 /* This define is named in the hardware, but actually just outputs 0. */
  49 # define DPI_FORMAT_9BIT_666_RGB        0
  50 /* Outputs 00000000rrrrrggggggbbbbb */
  51 # define DPI_FORMAT_16BIT_565_RGB_1     1
  52 /* Outputs 000rrrrr00gggggg000bbbbb */
  53 # define DPI_FORMAT_16BIT_565_RGB_2     2
  54 /* Outputs 00rrrrr000gggggg00bbbbb0 */
  55 # define DPI_FORMAT_16BIT_565_RGB_3     3
  56 /* Outputs 000000rrrrrrggggggbbbbbb */
  57 # define DPI_FORMAT_18BIT_666_RGB_1     4
  58 /* Outputs 00rrrrrr00gggggg00bbbbbb */
  59 # define DPI_FORMAT_18BIT_666_RGB_2     5
  60 /* Outputs rrrrrrrrggggggggbbbbbbbb */
  61 # define DPI_FORMAT_24BIT_888_RGB       6
  62
  63 /* Reverses the polarity of the corresponding signal */
  64 # define DPI_PIXEL_CLK_INVERT           BIT(10)
  65 # define DPI_HSYNC_INVERT               BIT(9)
  66 # define DPI_VSYNC_INVERT               BIT(8)
  67 # define DPI_OUTPUT_ENABLE_INVERT       BIT(7)
  68
  69 /* Outputs the signal the falling clock edge instead of rising. */
  70 # define DPI_HSYNC_NEGATE               BIT(6)
  71 # define DPI_VSYNC_NEGATE               BIT(5)
  72 # define DPI_OUTPUT_ENABLE_NEGATE       BIT(4)
  73
  74 /* Disables the signal */
  75 # define DPI_HSYNC_DISABLE              BIT(3)
  76 # define DPI_VSYNC_DISABLE              BIT(2)
  77 # define DPI_OUTPUT_ENABLE_DISABLE      BIT(1)
  78
  79 /* Power gate to the device, full reset at 0 -> 1 transition */
  80 # define DPI_ENABLE                     BIT(0)
  81
  82 /* All other registers besides DPI_C return the ID */
  83 #define DPI_ID                  0x04
  84 # define DPI_ID_VALUE           0x00647069
  85
  86 /* General DPI hardware state. */
  87 struct vc4_dpi {
  88         struct vc4_encoder encoder;
  89
  90         struct platform_device *pdev;
  91
  92         void __iomem *regs;
  93
  94         struct clk *pixel_clock;
  95         struct clk *core_clock;
  96
  97         struct debugfs_regset32 regset;
  98 };
  99
 100 #define to_vc4_dpi(_encoder)                                            \
 101         container_of_const(_encoder, struct vc4_dpi, encoder.base)
 102
 103 #define DPI_READ(offset)                                                                \
 104         ({                                                                              \
 105                 kunit_fail_current_test("Accessing a register in a unit test!\n");      \
 106                 readl(dpi->regs + (offset));                                            \
 107         })
 108
 109 #define DPI_WRITE(offset, val)                                                          \
 110         do {                                                                            \
 111                 kunit_fail_current_test("Accessing a register in a unit test!\n");      \
 112                 writel(val, dpi->regs + (offset));                                      \
 113         } while (0)
 114
 115 static const struct debugfs_reg32 dpi_regs[] = {
 116         VC4_REG32(DPI_C),
 117         VC4_REG32(DPI_ID),
 118 };
 119
 120 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 121 {
 122         struct drm_device *dev = encoder->dev;
 123         struct vc4_dpi *dpi = to_vc4_dpi(encoder);
 124         int idx;
 125
 126         if (!drm_dev_enter(dev, &idx))
 127                 return;
 128
 129         clk_disable_unprepare(dpi->pixel_clock);
 130
 131         drm_dev_exit(idx);
 132 }
 133
 134 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 135 {
 136         struct drm_device *dev = encoder->dev;
 137         struct drm_display_mode *mode = &encoder->crtc->mode;
 138         struct vc4_dpi *dpi = to_vc4_dpi(encoder);
 139         struct drm_connector_list_iter conn_iter;
 140         struct drm_connector *connector = NULL, *connector_scan;
 141         u32 dpi_c = DPI_ENABLE;
 142         int idx;
 143         int ret;
 144
 145         /* Look up the connector attached to DPI so we can get the
 146          * bus_format.  Ideally the bridge would tell us the
 147          * bus_format we want, but it doesn't yet, so assume that it's
 148          * uniform throughout the bridge chain.
 149          */
 150         drm_connector_list_iter_begin(dev, &conn_iter);
 151         drm_for_each_connector_iter(connector_scan, &conn_iter) {
 152                 if (connector_scan->encoder == encoder) {
 153                         connector = connector_scan;
 154                         break;
 155                 }
 156         }
 157         drm_connector_list_iter_end(&conn_iter);
 158
 159         /* Default to 18bit if no connector or format found. */
 160         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, DPI_FORMAT);
 161
 162         if (connector) {
 163                 if (connector->display_info.num_bus_formats) {
 164                         u32 bus_format = connector->display_info.bus_formats[0];
 165
 166                         dpi_c &= ~DPI_FORMAT_MASK;
 167
 168                         switch (bus_format) {
 169                         case MEDIA_BUS_FMT_RGB888_1X24:
 170                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 171                                                        DPI_FORMAT);
 172                                 break;
 173                         case MEDIA_BUS_FMT_BGR888_1X24:
 174                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 175                                                        DPI_FORMAT);
 176                                 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR,
 177                                                        DPI_ORDER);
 178                                 break;
 179                         case MEDIA_BUS_FMT_BGR666_1X24_CPADHI:
 180                                 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 181                                 fallthrough;
 182                         case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 183                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 184                                                        DPI_FORMAT);
 185                                 break;
 186                         case MEDIA_BUS_FMT_BGR666_1X18:
 187                                 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 188                                 fallthrough;
 189                         case MEDIA_BUS_FMT_RGB666_1X18:
 190                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 191                                                        DPI_FORMAT);
 192                                 break;
 193                         case MEDIA_BUS_FMT_RGB565_1X16:
 194                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_1,
 195                                                        DPI_FORMAT);
 196                                 break;
 197                         case MEDIA_BUS_FMT_RGB565_1X24_CPADHI:
 198                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_2,
 199                                                        DPI_FORMAT);
 200                                 break;
 201                         default:
 202                                 drm_err(dev, "Unknown media bus format %d\n",
 203                                         bus_format);
 204                                 break;
 205                         }
 206                 }
 207
 208                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
 209                         dpi_c |= DPI_PIXEL_CLK_INVERT;
 210
 211                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
 212                         dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 213         }
 214
 215         if (mode->flags & DRM_MODE_FLAG_CSYNC) {
 216                 if (mode->flags & DRM_MODE_FLAG_NCSYNC)
 217                         dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 218         } else {
 219                 dpi_c |= DPI_OUTPUT_ENABLE_MODE;
 220
 221                 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 222                         dpi_c |= DPI_HSYNC_INVERT;
 223                 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 224                         dpi_c |= DPI_HSYNC_DISABLE;
 225
 226                 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 227                         dpi_c |= DPI_VSYNC_INVERT;
 228                 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 229                         dpi_c |= DPI_VSYNC_DISABLE;
 230         }
 231
 232         if (!drm_dev_enter(dev, &idx))
 233                 return;
 234
 235         DPI_WRITE(DPI_C, dpi_c);
 236
 237         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 238         if (ret)
 239                 drm_err(dev, "Failed to set clock rate: %d\n", ret);
 240
 241         ret = clk_prepare_enable(dpi->pixel_clock);
 242         if (ret)
 243                 drm_err(dev, "Failed to set clock rate: %d\n", ret);
 244
 245         drm_dev_exit(idx);
 246 }
 247
 248 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
 249                                                        const struct drm_display_mode *mode)
 250 {
 251         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 252                 return MODE_NO_INTERLACE;
 253
 254         return MODE_OK;
 255 }
 256
 257 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 258         .disable = vc4_dpi_encoder_disable,
 259         .enable = vc4_dpi_encoder_enable,
 260         .mode_valid = vc4_dpi_encoder_mode_valid,
 261 };
 262
 263 static int vc4_dpi_late_register(struct drm_encoder *encoder)
 264 {
 265         struct drm_device *drm = encoder->dev;
 266         struct vc4_dpi *dpi = to_vc4_dpi(encoder);
 267
 268         vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset);
 269
 270         return 0;
 271 }
 272
 273 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 274         .late_register = vc4_dpi_late_register,
 275 };
 276
 277 static const struct of_device_id vc4_dpi_dt_match[] = {
 278         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 279         {}
 280 };
 281
 282 /* Sets up the next link in the display chain, whether it's a panel or
 283  * a bridge.
 284  */
 285 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 286 {
 287         struct drm_device *drm = dpi->encoder.base.dev;
 288         struct device *dev = &dpi->pdev->dev;
 289         struct drm_bridge *bridge;
 290
 291         bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0);
 292         if (IS_ERR(bridge)) {
 293                 /* If nothing was connected in the DT, that's not an
 294                  * error.
 295                  */
 296                 if (PTR_ERR(bridge) == -ENODEV)
 297                         return 0;
 298                 else
 299                         return PTR_ERR(bridge);
 300         }
 301
 302         return drm_bridge_attach(&dpi->encoder.base, bridge, NULL, 0);
 303 }
 304
 305 static void vc4_dpi_disable_clock(void *ptr)
 306 {
 307         struct vc4_dpi *dpi = ptr;
 308
 309         clk_disable_unprepare(dpi->core_clock);
 310 }
 311
 312 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 313 {
 314         struct platform_device *pdev = to_platform_device(dev);
 315         struct drm_device *drm = dev_get_drvdata(master);
 316         struct vc4_dpi *dpi;
 317         int ret;
 318
 319         dpi = drmm_kzalloc(drm, sizeof(*dpi), GFP_KERNEL);
 320         if (!dpi)
 321                 return -ENOMEM;
 322
 323         dpi->encoder.type = VC4_ENCODER_TYPE_DPI;
 324         dpi->pdev = pdev;
 325         dpi->regs = vc4_ioremap_regs(pdev, 0);
 326         if (IS_ERR(dpi->regs))
 327                 return PTR_ERR(dpi->regs);
 328         dpi->regset.base = dpi->regs;
 329         dpi->regset.regs = dpi_regs;
 330         dpi->regset.nregs = ARRAY_SIZE(dpi_regs);
 331
 332         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 333                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 334                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 335                 return -ENODEV;
 336         }
 337
 338         dpi->core_clock = devm_clk_get(dev, "core");
 339         if (IS_ERR(dpi->core_clock)) {
 340                 ret = PTR_ERR(dpi->core_clock);
 341                 if (ret != -EPROBE_DEFER)
 342                         drm_err(drm, "Failed to get core clock: %d\n", ret);
 343                 return ret;
 344         }
 345
 346         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 347         if (IS_ERR(dpi->pixel_clock)) {
 348                 ret = PTR_ERR(dpi->pixel_clock);
 349                 if (ret != -EPROBE_DEFER)
 350                         drm_err(drm, "Failed to get pixel clock: %d\n", ret);
 351                 return ret;
 352         }
 353
 354         ret = clk_prepare_enable(dpi->core_clock);
 355         if (ret) {
 356                 drm_err(drm, "Failed to turn on core clock: %d\n", ret);
 357                 return ret;
 358         }
 359
 360         ret = devm_add_action_or_reset(dev, vc4_dpi_disable_clock, dpi);
 361         if (ret)
 362                 return ret;
 363
 364         ret = drmm_encoder_init(drm, &dpi->encoder.base,
 365                                 &vc4_dpi_encoder_funcs,
 366                                 DRM_MODE_ENCODER_DPI,
 367                                 NULL);
 368         if (ret)
 369                 return ret;
 370
 371         drm_encoder_helper_add(&dpi->encoder.base, &vc4_dpi_encoder_helper_funcs);
 372
 373         ret = vc4_dpi_init_bridge(dpi);
 374         if (ret)
 375                 return ret;
 376
 377         dev_set_drvdata(dev, dpi);
 378
 379         return 0;
 380 }
 381
 382 static const struct component_ops vc4_dpi_ops = {
 383         .bind   = vc4_dpi_bind,
 384 };
 385
 386 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 387 {
 388         return component_add(&pdev->dev, &vc4_dpi_ops);
 389 }
 390
 391 static void vc4_dpi_dev_remove(struct platform_device *pdev)
 392 {
 393         component_del(&pdev->dev, &vc4_dpi_ops);
 394 }
 395
 396 struct platform_driver vc4_dpi_driver = {
 397         .probe = vc4_dpi_dev_probe,
 398         .remove = vc4_dpi_dev_remove,
 399         .driver = {
 400                 .name = "vc4_dpi",
 401                 .of_match_table = vc4_dpi_dt_match,
 402         },
 403 };