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/of_graph.h>
  26 #include <linux/of_platform.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 static inline struct vc4_dpi *
 101 to_vc4_dpi(struct drm_encoder *encoder)
 102 {
 103         return container_of(encoder, struct vc4_dpi, encoder.base);
 104 }
 105
 106 #define DPI_READ(offset) readl(dpi->regs + (offset))
 107 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
 108
 109 static const struct debugfs_reg32 dpi_regs[] = {
 110         VC4_REG32(DPI_C),
 111         VC4_REG32(DPI_ID),
 112 };
 113
 114 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 115 {
 116         struct drm_device *dev = encoder->dev;
 117         struct vc4_dpi *dpi = to_vc4_dpi(encoder);
 118         int idx;
 119
 120         if (!drm_dev_enter(dev, &idx))
 121                 return;
 122
 123         clk_disable_unprepare(dpi->pixel_clock);
 124
 125         drm_dev_exit(idx);
 126 }
 127
 128 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 129 {
 130         struct drm_device *dev = encoder->dev;
 131         struct drm_display_mode *mode = &encoder->crtc->mode;
 132         struct vc4_dpi *dpi = to_vc4_dpi(encoder);
 133         struct drm_connector_list_iter conn_iter;
 134         struct drm_connector *connector = NULL, *connector_scan;
 135         u32 dpi_c = DPI_ENABLE;
 136         int idx;
 137         int ret;
 138
 139         /* Look up the connector attached to DPI so we can get the
 140          * bus_format.  Ideally the bridge would tell us the
 141          * bus_format we want, but it doesn't yet, so assume that it's
 142          * uniform throughout the bridge chain.
 143          */
 144         drm_connector_list_iter_begin(dev, &conn_iter);
 145         drm_for_each_connector_iter(connector_scan, &conn_iter) {
 146                 if (connector_scan->encoder == encoder) {
 147                         connector = connector_scan;
 148                         break;
 149                 }
 150         }
 151         drm_connector_list_iter_end(&conn_iter);
 152
 153         /* Default to 24bit if no connector or format found. */
 154         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
 155
 156         if (connector) {
 157                 if (connector->display_info.num_bus_formats) {
 158                         u32 bus_format = connector->display_info.bus_formats[0];
 159
 160                         dpi_c &= ~DPI_FORMAT_MASK;
 161
 162                         switch (bus_format) {
 163                         case MEDIA_BUS_FMT_RGB888_1X24:
 164                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 165                                                        DPI_FORMAT);
 166                                 break;
 167                         case MEDIA_BUS_FMT_BGR888_1X24:
 168                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 169                                                        DPI_FORMAT);
 170                                 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR,
 171                                                        DPI_ORDER);
 172                                 break;
 173                         case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 174                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 175                                                        DPI_FORMAT);
 176                                 break;
 177                         case MEDIA_BUS_FMT_RGB666_1X18:
 178                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 179                                                        DPI_FORMAT);
 180                                 break;
 181                         case MEDIA_BUS_FMT_RGB565_1X16:
 182                                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 183                                                        DPI_FORMAT);
 184                                 break;
 185                         default:
 186                                 DRM_ERROR("Unknown media bus format %d\n",
 187                                           bus_format);
 188                                 break;
 189                         }
 190                 }
 191
 192                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
 193                         dpi_c |= DPI_PIXEL_CLK_INVERT;
 194
 195                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
 196                         dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 197         }
 198
 199         if (mode->flags & DRM_MODE_FLAG_CSYNC) {
 200                 if (mode->flags & DRM_MODE_FLAG_NCSYNC)
 201                         dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 202         } else {
 203                 dpi_c |= DPI_OUTPUT_ENABLE_MODE;
 204
 205                 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 206                         dpi_c |= DPI_HSYNC_INVERT;
 207                 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 208                         dpi_c |= DPI_HSYNC_DISABLE;
 209
 210                 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 211                         dpi_c |= DPI_VSYNC_INVERT;
 212                 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 213                         dpi_c |= DPI_VSYNC_DISABLE;
 214         }
 215
 216         if (!drm_dev_enter(dev, &idx))
 217                 return;
 218
 219         DPI_WRITE(DPI_C, dpi_c);
 220
 221         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 222         if (ret)
 223                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 224
 225         ret = clk_prepare_enable(dpi->pixel_clock);
 226         if (ret)
 227                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 228
 229         drm_dev_exit(idx);
 230 }
 231
 232 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
 233                                                        const struct drm_display_mode *mode)
 234 {
 235         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 236                 return MODE_NO_INTERLACE;
 237
 238         return MODE_OK;
 239 }
 240
 241 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 242         .disable = vc4_dpi_encoder_disable,
 243         .enable = vc4_dpi_encoder_enable,
 244         .mode_valid = vc4_dpi_encoder_mode_valid,
 245 };
 246
 247 static const struct of_device_id vc4_dpi_dt_match[] = {
 248         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 249         {}
 250 };
 251
 252 /* Sets up the next link in the display chain, whether it's a panel or
 253  * a bridge.
 254  */
 255 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 256 {
 257         struct drm_device *drm = dpi->encoder.base.dev;
 258         struct device *dev = &dpi->pdev->dev;
 259         struct drm_bridge *bridge;
 260
 261         bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0);
 262         if (IS_ERR(bridge)) {
 263                 /* If nothing was connected in the DT, that's not an
 264                  * error.
 265                  */
 266                 if (PTR_ERR(bridge) == -ENODEV)
 267                         return 0;
 268                 else
 269                         return PTR_ERR(bridge);
 270         }
 271
 272         return drm_bridge_attach(&dpi->encoder.base, bridge, NULL, 0);
 273 }
 274
 275 static void vc4_dpi_disable_clock(void *ptr)
 276 {
 277         struct vc4_dpi *dpi = ptr;
 278
 279         clk_disable_unprepare(dpi->core_clock);
 280 }
 281
 282 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 283 {
 284         struct platform_device *pdev = to_platform_device(dev);
 285         struct drm_device *drm = dev_get_drvdata(master);
 286         struct vc4_dpi *dpi;
 287         int ret;
 288
 289         dpi = drmm_kzalloc(drm, sizeof(*dpi), GFP_KERNEL);
 290         if (!dpi)
 291                 return -ENOMEM;
 292
 293         dpi->encoder.type = VC4_ENCODER_TYPE_DPI;
 294         dpi->pdev = pdev;
 295         dpi->regs = vc4_ioremap_regs(pdev, 0);
 296         if (IS_ERR(dpi->regs))
 297                 return PTR_ERR(dpi->regs);
 298         dpi->regset.base = dpi->regs;
 299         dpi->regset.regs = dpi_regs;
 300         dpi->regset.nregs = ARRAY_SIZE(dpi_regs);
 301
 302         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 303                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 304                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 305                 return -ENODEV;
 306         }
 307
 308         dpi->core_clock = devm_clk_get(dev, "core");
 309         if (IS_ERR(dpi->core_clock)) {
 310                 ret = PTR_ERR(dpi->core_clock);
 311                 if (ret != -EPROBE_DEFER)
 312                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 313                 return ret;
 314         }
 315
 316         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 317         if (IS_ERR(dpi->pixel_clock)) {
 318                 ret = PTR_ERR(dpi->pixel_clock);
 319                 if (ret != -EPROBE_DEFER)
 320                         DRM_ERROR("Failed to get pixel clock: %d\n", ret);
 321                 return ret;
 322         }
 323
 324         ret = clk_prepare_enable(dpi->core_clock);
 325         if (ret) {
 326                 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
 327                 return ret;
 328         }
 329
 330         ret = devm_add_action_or_reset(dev, vc4_dpi_disable_clock, dpi);
 331         if (ret)
 332                 return ret;
 333
 334         ret = drmm_encoder_init(drm, &dpi->encoder.base,
 335                                 NULL,
 336                                 DRM_MODE_ENCODER_DPI,
 337                                 NULL);
 338         if (ret)
 339                 return ret;
 340
 341         drm_encoder_helper_add(&dpi->encoder.base, &vc4_dpi_encoder_helper_funcs);
 342
 343         ret = vc4_dpi_init_bridge(dpi);
 344         if (ret)
 345                 return ret;
 346
 347         dev_set_drvdata(dev, dpi);
 348
 349         vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset);
 350
 351         return 0;
 352 }
 353
 354 static const struct component_ops vc4_dpi_ops = {
 355         .bind   = vc4_dpi_bind,
 356 };
 357
 358 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 359 {
 360         return component_add(&pdev->dev, &vc4_dpi_ops);
 361 }
 362
 363 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 364 {
 365         component_del(&pdev->dev, &vc4_dpi_ops);
 366         return 0;
 367 }
 368
 369 struct platform_driver vc4_dpi_driver = {
 370         .probe = vc4_dpi_dev_probe,
 371         .remove = vc4_dpi_dev_remove,
 372         .driver = {
 373                 .name = "vc4_dpi",
 374                 .of_match_table = vc4_dpi_dt_match,
 375         },
 376 };