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_crtc_helper.h>
  28 #include <drm/drm_edid.h>
  29 #include <drm/drm_of.h>
  30 #include <drm/drm_panel.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         struct drm_connector *connector;
 100         struct drm_bridge *bridge;
 101         bool is_panel_bridge;
 102
 103         void __iomem *regs;
 104
 105         struct clk *pixel_clock;
 106         struct clk *core_clock;
 107 };
 108
 109 #define DPI_READ(offset) readl(dpi->regs + (offset))
 110 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
 111
 112 /* VC4 DPI encoder KMS struct */
 113 struct vc4_dpi_encoder {
 114         struct vc4_encoder base;
 115         struct vc4_dpi *dpi;
 116 };
 117
 118 static inline struct vc4_dpi_encoder *
 119 to_vc4_dpi_encoder(struct drm_encoder *encoder)
 120 {
 121         return container_of(encoder, struct vc4_dpi_encoder, base.base);
 122 }
 123
 124 #define DPI_REG(reg) { reg, #reg }
 125 static const struct {
 126         u32 reg;
 127         const char *name;
 128 } dpi_regs[] = {
 129         DPI_REG(DPI_C),
 130         DPI_REG(DPI_ID),
 131 };
 132
 133 #ifdef CONFIG_DEBUG_FS
 134 int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
 135 {
 136         struct drm_info_node *node = (struct drm_info_node *)m->private;
 137         struct drm_device *dev = node->minor->dev;
 138         struct vc4_dev *vc4 = to_vc4_dev(dev);
 139         struct vc4_dpi *dpi = vc4->dpi;
 140         int i;
 141
 142         if (!dpi)
 143                 return 0;
 144
 145         for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
 146                 seq_printf(m, "%s (0x%04x): 0x%08x\n",
 147                            dpi_regs[i].name, dpi_regs[i].reg,
 148                            DPI_READ(dpi_regs[i].reg));
 149         }
 150
 151         return 0;
 152 }
 153 #endif
 154
 155 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 156         .destroy = drm_encoder_cleanup,
 157 };
 158
 159 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 160 {
 161         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 162         struct vc4_dpi *dpi = vc4_encoder->dpi;
 163
 164         clk_disable_unprepare(dpi->pixel_clock);
 165 }
 166
 167 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 168 {
 169         struct drm_display_mode *mode = &encoder->crtc->mode;
 170         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 171         struct vc4_dpi *dpi = vc4_encoder->dpi;
 172         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
 173         int ret;
 174
 175         if (dpi->connector->display_info.num_bus_formats) {
 176                 u32 bus_format = dpi->connector->display_info.bus_formats[0];
 177
 178                 switch (bus_format) {
 179                 case MEDIA_BUS_FMT_RGB888_1X24:
 180                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 181                                                DPI_FORMAT);
 182                         break;
 183                 case MEDIA_BUS_FMT_BGR888_1X24:
 184                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 185                                                DPI_FORMAT);
 186                         dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 187                         break;
 188                 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 189                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 190                                                DPI_FORMAT);
 191                         break;
 192                 case MEDIA_BUS_FMT_RGB666_1X18:
 193                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 194                                                DPI_FORMAT);
 195                         break;
 196                 case MEDIA_BUS_FMT_RGB565_1X16:
 197                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 198                                                DPI_FORMAT);
 199                         break;
 200                 default:
 201                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
 202                         break;
 203                 }
 204         }
 205
 206         if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 207                 dpi_c |= DPI_HSYNC_INVERT;
 208         else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
 209                 dpi_c |= DPI_HSYNC_DISABLE;
 210
 211         if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 212                 dpi_c |= DPI_VSYNC_INVERT;
 213         else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
 214                 dpi_c |= DPI_VSYNC_DISABLE;
 215
 216         DPI_WRITE(DPI_C, dpi_c);
 217
 218         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 219         if (ret)
 220                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 221
 222         ret = clk_prepare_enable(dpi->pixel_clock);
 223         if (ret)
 224                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 225 }
 226
 227 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
 228                                                        const struct drm_display_mode *mode)
 229 {
 230         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 231                 return MODE_NO_INTERLACE;
 232
 233         return MODE_OK;
 234 }
 235
 236 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 237         .disable = vc4_dpi_encoder_disable,
 238         .enable = vc4_dpi_encoder_enable,
 239         .mode_valid = vc4_dpi_encoder_mode_valid,
 240 };
 241
 242 static const struct of_device_id vc4_dpi_dt_match[] = {
 243         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 244         {}
 245 };
 246
 247 /* Sets up the next link in the display chain, whether it's a panel or
 248  * a bridge.
 249  */
 250 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 251 {
 252         struct device *dev = &dpi->pdev->dev;
 253         struct drm_panel *panel;
 254         int ret;
 255
 256         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
 257                                           &panel, &dpi->bridge);
 258         if (ret) {
 259                 /* If nothing was connected in the DT, that's not an
 260                  * error.
 261                  */
 262                 if (ret == -ENODEV)
 263                         return 0;
 264                 else
 265                         return ret;
 266         }
 267
 268         if (panel) {
 269                 dpi->bridge = drm_panel_bridge_add(panel,
 270                                                    DRM_MODE_CONNECTOR_DPI);
 271                 dpi->is_panel_bridge = true;
 272         }
 273
 274         return drm_bridge_attach(dpi->encoder, dpi->bridge, NULL);
 275 }
 276
 277 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 278 {
 279         struct platform_device *pdev = to_platform_device(dev);
 280         struct drm_device *drm = dev_get_drvdata(master);
 281         struct vc4_dev *vc4 = to_vc4_dev(drm);
 282         struct vc4_dpi *dpi;
 283         struct vc4_dpi_encoder *vc4_dpi_encoder;
 284         int ret;
 285
 286         dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
 287         if (!dpi)
 288                 return -ENOMEM;
 289
 290         vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
 291                                        GFP_KERNEL);
 292         if (!vc4_dpi_encoder)
 293                 return -ENOMEM;
 294         vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
 295         vc4_dpi_encoder->dpi = dpi;
 296         dpi->encoder = &vc4_dpi_encoder->base.base;
 297
 298         dpi->pdev = pdev;
 299         dpi->regs = vc4_ioremap_regs(pdev, 0);
 300         if (IS_ERR(dpi->regs))
 301                 return PTR_ERR(dpi->regs);
 302
 303         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 304                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 305                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 306                 return -ENODEV;
 307         }
 308
 309         dpi->core_clock = devm_clk_get(dev, "core");
 310         if (IS_ERR(dpi->core_clock)) {
 311                 ret = PTR_ERR(dpi->core_clock);
 312                 if (ret != -EPROBE_DEFER)
 313                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 314                 return ret;
 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
 328         drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
 329                          DRM_MODE_ENCODER_DPI, NULL);
 330         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 331
 332         ret = vc4_dpi_init_bridge(dpi);
 333         if (ret)
 334                 goto err_destroy_encoder;
 335
 336         dev_set_drvdata(dev, dpi);
 337
 338         vc4->dpi = dpi;
 339
 340         return 0;
 341
 342 err_destroy_encoder:
 343         drm_encoder_cleanup(dpi->encoder);
 344         clk_disable_unprepare(dpi->core_clock);
 345         return ret;
 346 }
 347
 348 static void vc4_dpi_unbind(struct device *dev, struct device *master,
 349                            void *data)
 350 {
 351         struct drm_device *drm = dev_get_drvdata(master);
 352         struct vc4_dev *vc4 = to_vc4_dev(drm);
 353         struct vc4_dpi *dpi = dev_get_drvdata(dev);
 354
 355         if (dpi->is_panel_bridge)
 356                 drm_panel_bridge_remove(dpi->bridge);
 357
 358         drm_encoder_cleanup(dpi->encoder);
 359
 360         clk_disable_unprepare(dpi->core_clock);
 361
 362         vc4->dpi = NULL;
 363 }
 364
 365 static const struct component_ops vc4_dpi_ops = {
 366         .bind   = vc4_dpi_bind,
 367         .unbind = vc4_dpi_unbind,
 368 };
 369
 370 static int vc4_dpi_dev_probe(struct platform_device *pdev)
 371 {
 372         return component_add(&pdev->dev, &vc4_dpi_ops);
 373 }
 374
 375 static int vc4_dpi_dev_remove(struct platform_device *pdev)
 376 {
 377         component_del(&pdev->dev, &vc4_dpi_ops);
 378         return 0;
 379 }
 380
 381 struct platform_driver vc4_dpi_driver = {
 382         .probe = vc4_dpi_dev_probe,
 383         .remove = vc4_dpi_dev_remove,
 384         .driver = {
 385                 .name = "vc4_dpi",
 386                 .of_match_table = vc4_dpi_dt_match,
 387         },
 388 };