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
 101         void __iomem *regs;
 102
 103         struct clk *pixel_clock;
 104         struct clk *core_clock;
 105 };
 106
 107 #define DPI_READ(offset) readl(dpi->regs + (offset))
 108 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
 109
 110 /* VC4 DPI encoder KMS struct */
 111 struct vc4_dpi_encoder {
 112         struct vc4_encoder base;
 113         struct vc4_dpi *dpi;
 114 };
 115
 116 static inline struct vc4_dpi_encoder *
 117 to_vc4_dpi_encoder(struct drm_encoder *encoder)
 118 {
 119         return container_of(encoder, struct vc4_dpi_encoder, base.base);
 120 }
 121
 122 #define DPI_REG(reg) { reg, #reg }
 123 static const struct {
 124         u32 reg;
 125         const char *name;
 126 } dpi_regs[] = {
 127         DPI_REG(DPI_C),
 128         DPI_REG(DPI_ID),
 129 };
 130
 131 #ifdef CONFIG_DEBUG_FS
 132 int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
 133 {
 134         struct drm_info_node *node = (struct drm_info_node *)m->private;
 135         struct drm_device *dev = node->minor->dev;
 136         struct vc4_dev *vc4 = to_vc4_dev(dev);
 137         struct vc4_dpi *dpi = vc4->dpi;
 138         int i;
 139
 140         if (!dpi)
 141                 return 0;
 142
 143         for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
 144                 seq_printf(m, "%s (0x%04x): 0x%08x\n",
 145                            dpi_regs[i].name, dpi_regs[i].reg,
 146                            DPI_READ(dpi_regs[i].reg));
 147         }
 148
 149         return 0;
 150 }
 151 #endif
 152
 153 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
 154         .destroy = drm_encoder_cleanup,
 155 };
 156
 157 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
 158 {
 159         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 160         struct vc4_dpi *dpi = vc4_encoder->dpi;
 161
 162         clk_disable_unprepare(dpi->pixel_clock);
 163 }
 164
 165 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 166 {
 167         struct drm_display_mode *mode = &encoder->crtc->mode;
 168         struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
 169         struct vc4_dpi *dpi = vc4_encoder->dpi;
 170         u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
 171         int ret;
 172
 173         if (dpi->connector->display_info.num_bus_formats) {
 174                 u32 bus_format = dpi->connector->display_info.bus_formats[0];
 175
 176                 switch (bus_format) {
 177                 case MEDIA_BUS_FMT_RGB888_1X24:
 178                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 179                                                DPI_FORMAT);
 180                         break;
 181                 case MEDIA_BUS_FMT_BGR888_1X24:
 182                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 183                                                DPI_FORMAT);
 184                         dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
 185                         break;
 186                 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 187                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
 188                                                DPI_FORMAT);
 189                         break;
 190                 case MEDIA_BUS_FMT_RGB666_1X18:
 191                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
 192                                                DPI_FORMAT);
 193                         break;
 194                 case MEDIA_BUS_FMT_RGB565_1X16:
 195                         dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 196                                                DPI_FORMAT);
 197                         break;
 198                 default:
 199                         DRM_ERROR("Unknown media bus format %d\n", bus_format);
 200                         break;
 201                 }
 202         }
 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         DPI_WRITE(DPI_C, dpi_c);
 215
 216         ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
 217         if (ret)
 218                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 219
 220         ret = clk_prepare_enable(dpi->pixel_clock);
 221         if (ret)
 222                 DRM_ERROR("Failed to set clock rate: %d\n", ret);
 223 }
 224
 225 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
 226                                                        const struct drm_display_mode *mode)
 227 {
 228         if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 229                 return MODE_NO_INTERLACE;
 230
 231         return MODE_OK;
 232 }
 233
 234 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
 235         .disable = vc4_dpi_encoder_disable,
 236         .enable = vc4_dpi_encoder_enable,
 237         .mode_valid = vc4_dpi_encoder_mode_valid,
 238 };
 239
 240 static const struct of_device_id vc4_dpi_dt_match[] = {
 241         { .compatible = "brcm,bcm2835-dpi", .data = NULL },
 242         {}
 243 };
 244
 245 /* Sets up the next link in the display chain, whether it's a panel or
 246  * a bridge.
 247  */
 248 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 249 {
 250         struct device *dev = &dpi->pdev->dev;
 251         struct drm_panel *panel;
 252         struct drm_bridge *bridge;
 253         int ret;
 254
 255         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
 256                                           &panel, &bridge);
 257         if (ret) {
 258                 /* If nothing was connected in the DT, that's not an
 259                  * error.
 260                  */
 261                 if (ret == -ENODEV)
 262                         return 0;
 263                 else
 264                         return ret;
 265         }
 266
 267         if (panel)
 268                 bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
 269
 270         return drm_bridge_attach(dpi->encoder, bridge, NULL);
 271 }
 272
 273 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
 274 {
 275         struct platform_device *pdev = to_platform_device(dev);
 276         struct drm_device *drm = dev_get_drvdata(master);
 277         struct vc4_dev *vc4 = to_vc4_dev(drm);
 278         struct vc4_dpi *dpi;
 279         struct vc4_dpi_encoder *vc4_dpi_encoder;
 280         int ret;
 281
 282         dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
 283         if (!dpi)
 284                 return -ENOMEM;
 285
 286         vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
 287                                        GFP_KERNEL);
 288         if (!vc4_dpi_encoder)
 289                 return -ENOMEM;
 290         vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
 291         vc4_dpi_encoder->dpi = dpi;
 292         dpi->encoder = &vc4_dpi_encoder->base.base;
 293
 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
 299         if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
 300                 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
 301                         DPI_READ(DPI_ID), DPI_ID_VALUE);
 302                 return -ENODEV;
 303         }
 304
 305         dpi->core_clock = devm_clk_get(dev, "core");
 306         if (IS_ERR(dpi->core_clock)) {
 307                 ret = PTR_ERR(dpi->core_clock);
 308                 if (ret != -EPROBE_DEFER)
 309                         DRM_ERROR("Failed to get core clock: %d\n", ret);
 310                 return ret;
 311         }
 312         dpi->pixel_clock = devm_clk_get(dev, "pixel");
 313         if (IS_ERR(dpi->pixel_clock)) {
 314                 ret = PTR_ERR(dpi->pixel_clock);
 315                 if (ret != -EPROBE_DEFER)
 316                         DRM_ERROR("Failed to get pixel clock: %d\n", ret);
 317                 return ret;
 318         }
 319
 320         ret = clk_prepare_enable(dpi->core_clock);
 321         if (ret)
 322                 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
 323
 324         drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
 325                          DRM_MODE_ENCODER_DPI, NULL);
 326         drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
 327
 328         ret = vc4_dpi_init_bridge(dpi);
 329         if (ret)
 330                 goto err_destroy_encoder;
 331
 332         dev_set_drvdata(dev, dpi);
 333
 334         vc4->dpi = dpi;
 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 };