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.  On BCM2835, these can be routed out to GPIO0-27 with the
  22  * ALT2 function.
  23  */
  24
  25 #include <drm/drm_atomic_helper.h>
  26 #include <drm/drm_bridge.h>
  27 #include <drm/drm_edid.h>
  28 #include <drm/drm_of.h>
  29 #include <drm/drm_panel.h>
  30 #include <drm/drm_probe_helper.h>
  31 #include <linux/clk.h>
  32 #include <linux/component.h>
  33 #include <linux/of_graph.h>
  34 #include <linux/of_platform.h>
  35 #include "vc4_drv.h"
  36 #include "vc4_regs.h"
  37
  38 #define DPI_C                   0x00
  39 # define DPI_OUTPUT_ENABLE_MODE         BIT(16)
  40
  41 /* The order field takes the incoming 24 bit RGB from the pixel valve
  42  * and shuffles the 3 channels.
  43  */
  44 # define DPI_ORDER_MASK                 VC4_MASK(15, 14)
  45 # define DPI_ORDER_SHIFT                14
  46 # define DPI_ORDER_RGB                  0
  47 # define DPI_ORDER_BGR                  1
  48 # define DPI_ORDER_GRB                  2
  49 # define DPI_ORDER_BRG                  3
  50
  51 /* The format field takes the ORDER-shuffled pixel valve data and
  52  * formats it onto the output lines.
  53  */
  54 # define DPI_FORMAT_MASK                VC4_MASK(13, 11)
  55 # define DPI_FORMAT_SHIFT               11
  56 /* This define is named in the hardware, but actually just outputs 0. */
  57 # define DPI_FORMAT_9BIT_666_RGB        0
  58 /* Outputs 00000000rrrrrggggggbbbbb */
  59 # define DPI_FORMAT_16BIT_565_RGB_1     1
  60 /* Outputs 000rrrrr00gggggg000bbbbb */
  61 # define DPI_FORMAT_16BIT_565_RGB_2     2
  62 /* Outputs 00rrrrr000gggggg00bbbbb0 */
  63 # define DPI_FORMAT_16BIT_565_RGB_3     3
  64 /* Outputs 000000rrrrrrggggggbbbbbb */
  65 # define DPI_FORMAT_18BIT_666_RGB_1     4
  66 /* Outputs 00rrrrrr00gggggg00bbbbbb */
  67 # define DPI_FORMAT_18BIT_666_RGB_2     5
  68 /* Outputs rrrrrrrrggggggggbbbbbbbb */
  69 # define DPI_FORMAT_24BIT_888_RGB       6
  70
  71 /* Reverses the polarity of the corresponding signal */
  72 # define DPI_PIXEL_CLK_INVERT           BIT(10)
  73 # define DPI_HSYNC_INVERT               BIT(9)
  74 # define DPI_VSYNC_INVERT               BIT(8)
  75 # define DPI_OUTPUT_ENABLE_INVERT       BIT(7)
  76
  77 /* Outputs the signal the falling clock edge instead of rising. */
  78 # define DPI_HSYNC_NEGATE               BIT(6)
  79 # define DPI_VSYNC_NEGATE               BIT(5)
  80 # define DPI_OUTPUT_ENABLE_NEGATE       BIT(4)
  81
  82 /* Disables the signal */
  83 # define DPI_HSYNC_DISABLE              BIT(3)
  84 # define DPI_VSYNC_DISABLE              BIT(2)
  85 # define DPI_OUTPUT_ENABLE_DISABLE      BIT(1)
  86
  87 /* Power gate to the device, full reset at 0 -> 1 transition */
  88 # define DPI_ENABLE                     BIT(0)
  89
  90 /* All other registers besides DPI_C return the ID */
  91 #define DPI_ID                  0x04
  92 # define DPI_ID_VALUE           0x00647069
  93
  94 /* General DPI hardware state. */
  95 struct vc4_dpi {
  96         struct platform_device *pdev;
  97
  98         struct drm_encoder *encoder;
  99
 100         void __iomem *regs;
 101
 102         struct clk *pixel_clock;
 103         struct clk *core_clock;
 104
 105         struct debugfs_regset32 regset;
 106 };
 107
 108 #define DPI_READ(offset) readl(dpi->regs + (offset))
 109 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
 110
 111 /* VC4 DPI encoder KMS struct */
 112 struct vc4_dpi_encoder {
 113         struct vc4_encoder base;
 114         struct vc4_dpi *dpi;
 115 };
 116
 117 static inline struct vc4_dpi_encoder *
 118 to_vc4_dpi_encoder(struct drm_encoder *encoder)
 119 {
 120         return container_of(encoder, struct vc4_dpi_encoder, base.base);
 121 }
 122
 123 static const struct debugfs_reg32 dpi_regs[] = {
 124         VC4_REG32(DPI_C),
 125         VC4_REG32(DPI_ID),
 126 };
 127
 128 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 129         .destroy = drm_encoder_cleanup,
 130 };
 131
 132 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 133 {
 134         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 135         struct vc4_dpi *dpi = vc4_encoder->dpi;
 136
 137         clk_disable_unprepare(dpi->pixel_clock);
 138 }
 139
 140 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 141 {
 142         struct drm_device *dev = encoder->dev;
 143         struct drm_display_mode *mode = &encoder->crtc->mode;
 144         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 145         struct vc4_dpi *dpi = vc4_encoder->dpi;
 146         struct drm_connector_list_iter conn_iter;
 147         struct drm_connector *connector = NULL, *connector_scan;
 148         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
 149         int ret;
 150
 151         /* Look up the connector attached to DPI so we can get the
 152          * bus_format.  Ideally the bridge would tell us the
 153          * bus_format we want, but it doesn't yet, so assume that it's
 154          * uniform throughout the bridge chain.
 155          */
 156         drm_connector_list_iter_begin(dev, &conn_iter);
 157         drm_for_each_connector_iter(connector_scan, &conn_iter) {
 158                 if (connector_scan->encoder == encoder) {
 159                         connector = connector_scan;
 160                         break;
 161                 }
 162         }
 163         drm_connector_list_iter_end(&conn_iter);
 164
 165         if (connector && connector->display_info.num_bus_formats) {
 166                 u32 bus_format = connector->display_info.bus_formats[0];
 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, DPI_ORDER);
 177                         break;
 178                 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 179                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 180                                                DPI_FORMAT);
 181                         break;
 182                 case MEDIA_BUS_FMT_RGB666_1X18:
 183                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 184                                                DPI_FORMAT);
 185                         break;
 186                 case MEDIA_BUS_FMT_RGB565_1X16:
 187                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 188                                                DPI_FORMAT);
 189                         break;
 190                 default:
 191                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
 192                         break;
 193                 }
 194         } else {
 195                 /* Default to 24bit if no connector found. */
 196                 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
 197         }
 198
 199         if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 200                 dpi_c |= DPI_HSYNC_INVERT;
 201         else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 202                 dpi_c |= DPI_HSYNC_DISABLE;
 203
 204         if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 205                 dpi_c |= DPI_VSYNC_INVERT;
 206         else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 207                 dpi_c |= DPI_VSYNC_DISABLE;
 208
 209         DPI_WRITE(DPI_C, dpi_c);
 210
 211         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 212         if (ret)
 213                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 214
 215         ret = clk_prepare_enable(dpi->pixel_clock);
 216         if (ret)
 217                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 218 }
 219
 220 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
 221                                                        const struct drm_display_mode *mode)
 222 {
 223         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 224                 return MODE_NO_INTERLACE;
 225
 226         return MODE_OK;
 227 }
 228
 229 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 230         .disable = vc4_dpi_encoder_disable,
 231         .enable = vc4_dpi_encoder_enable,
 232         .mode_valid = vc4_dpi_encoder_mode_valid,
 233 };
 234
 235 static const struct of_device_id vc4_dpi_dt_match[] = {
 236         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 237         {}
 238 };
 239
 240 /* Sets up the next link in the display chain, whether it's a panel or
 241  * a bridge.
 242  */
 243 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 244 {
 245         struct device *dev = &dpi->pdev->dev;
 246         struct drm_panel *panel;
 247         struct drm_bridge *bridge;
 248         int ret;
 249
 250         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
 251                                           &panel, &bridge);
 252         if (ret) {
 253                 /* If nothing was connected in the DT, that's not an
 254                  * error.
 255                  */
 256                 if (ret == -ENODEV)
 257                         return 0;
 258                 else
 259                         return ret;
 260         }
 261
 262         if (panel)
 263                 bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
 264
 265         return drm_bridge_attach(dpi->encoder, bridge, NULL);
 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_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
 323                          DRM_MODE_ENCODER_DPI, NULL);
 324         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 325
 326         ret = vc4_dpi_init_bridge(dpi);
 327         if (ret)
 328                 goto err_destroy_encoder;
 329
 330         dev_set_drvdata(dev, dpi);
 331
 332         vc4->dpi = dpi;
 333
 334         vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset);
 335
 336         return 0;
 337
 338 err_destroy_encoder:
 339         drm_encoder_cleanup(dpi->encoder);
 340         clk_disable_unprepare(dpi->core_clock);
 341         return ret;
 342 }
 343
 344 static void vc4_dpi_unbind(struct device *dev, struct device *master,
 345                            void *data)
 346 {
 347         struct drm_device *drm = dev_get_drvdata(master);
 348         struct vc4_dev *vc4 = to_vc4_dev(drm);
 349         struct vc4_dpi *dpi = dev_get_drvdata(dev);
 350
 351         drm_of_panel_bridge_remove(dev->of_node, 0, 0);
 352
 353         drm_encoder_cleanup(dpi->encoder);
 354
 355         clk_disable_unprepare(dpi->core_clock);
 356
 357         vc4->dpi = NULL;
 358 }
 359
 360 static const struct component_ops vc4_dpi_ops = {
 361         .bind   = vc4_dpi_bind,
 362         .unbind = vc4_dpi_unbind,
 363 };
 364
 365 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 366 {
 367         return component_add(&pdev->dev, &vc4_dpi_ops);
 368 }
 369
 370 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 371 {
 372         component_del(&pdev->dev, &vc4_dpi_ops);
 373         return 0;
 374 }
 375
 376 struct platform_driver vc4_dpi_driver = {
 377         .probe = vc4_dpi_dev_probe,
 378         .remove = vc4_dpi_dev_remove,
 379         .driver = {
 380                 .name = "vc4_dpi",
 381                 .of_match_table = vc4_dpi_dt_match,
 382         },
 383 };