kernel/drivers/gpu/drm/udl/udl_modeset.c

   1 /*
   2  * Copyright (C) 2012 Red Hat
   3  *
   4  * based in parts on udlfb.c:
   5  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   6  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   7  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   8
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License v2. See the file COPYING in the main directory of this archive for
  11  * more details.
  12  */
  13
  14 #include <drm/drmP.h>
  15 #include <drm/drm_crtc.h>
  16 #include <drm/drm_crtc_helper.h>
  17 #include <drm/drm_plane_helper.h>
  18 #include "udl_drv.h"
  19
  20 /*
  21  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  22  * All operations are written to buffers which then later get sent to device
  23  */
  24 static char *udl_set_register(char *buf, u8 reg, u8 val)
  25 {
  26         *buf++ = 0xAF;
  27         *buf++ = 0x20;
  28         *buf++ = reg;
  29         *buf++ = val;
  30         return buf;
  31 }
  32
  33 static char *udl_vidreg_lock(char *buf)
  34 {
  35         return udl_set_register(buf, 0xFF, 0x00);
  36 }
  37
  38 static char *udl_vidreg_unlock(char *buf)
  39 {
  40         return udl_set_register(buf, 0xFF, 0xFF);
  41 }
  42
  43 /*
  44  * On/Off for driving the DisplayLink framebuffer to the display
  45  *  0x00 H and V sync on
  46  *  0x01 H and V sync off (screen blank but powered)
  47  *  0x07 DPMS powerdown (requires modeset to come back)
  48  */
  49 static char *udl_set_blank(char *buf, int dpms_mode)
  50 {
  51         u8 reg;
  52         switch (dpms_mode) {
  53         case DRM_MODE_DPMS_OFF:
  54                 reg = 0x07;
  55                 break;
  56         case DRM_MODE_DPMS_STANDBY:
  57                 reg = 0x05;
  58                 break;
  59         case DRM_MODE_DPMS_SUSPEND:
  60                 reg = 0x01;
  61                 break;
  62         case DRM_MODE_DPMS_ON:
  63                 reg = 0x00;
  64                 break;
  65         }
  66
  67         return udl_set_register(buf, 0x1f, reg);
  68 }
  69
  70 static char *udl_set_color_depth(char *buf, u8 selection)
  71 {
  72         return udl_set_register(buf, 0x00, selection);
  73 }
  74
  75 static char *udl_set_base16bpp(char *wrptr, u32 base)
  76 {
  77         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
  78         wrptr = udl_set_register(wrptr, 0x20, base >> 16);
  79         wrptr = udl_set_register(wrptr, 0x21, base >> 8);
  80         return udl_set_register(wrptr, 0x22, base);
  81 }
  82
  83 /*
  84  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
  85  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
  86  */
  87 static char *udl_set_base8bpp(char *wrptr, u32 base)
  88 {
  89         wrptr = udl_set_register(wrptr, 0x26, base >> 16);
  90         wrptr = udl_set_register(wrptr, 0x27, base >> 8);
  91         return udl_set_register(wrptr, 0x28, base);
  92 }
  93
  94 static char *udl_set_register_16(char *wrptr, u8 reg, u16 value)
  95 {
  96         wrptr = udl_set_register(wrptr, reg, value >> 8);
  97         return udl_set_register(wrptr, reg+1, value);
  98 }
  99
 100 /*
 101  * This is kind of weird because the controller takes some
 102  * register values in a different byte order than other registers.
 103  */
 104 static char *udl_set_register_16be(char *wrptr, u8 reg, u16 value)
 105 {
 106         wrptr = udl_set_register(wrptr, reg, value);
 107         return udl_set_register(wrptr, reg+1, value >> 8);
 108 }
 109
 110 /*
 111  * LFSR is linear feedback shift register. The reason we have this is
 112  * because the display controller needs to minimize the clock depth of
 113  * various counters used in the display path. So this code reverses the
 114  * provided value into the lfsr16 value by counting backwards to get
 115  * the value that needs to be set in the hardware comparator to get the
 116  * same actual count. This makes sense once you read above a couple of
 117  * times and think about it from a hardware perspective.
 118  */
 119 static u16 udl_lfsr16(u16 actual_count)
 120 {
 121         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 122
 123         while (actual_count--) {
 124                 lv =     ((lv << 1) |
 125                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 126                         & 0xFFFF;
 127         }
 128
 129         return (u16) lv;
 130 }
 131
 132 /*
 133  * This does LFSR conversion on the value that is to be written.
 134  * See LFSR explanation above for more detail.
 135  */
 136 static char *udl_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 137 {
 138         return udl_set_register_16(wrptr, reg, udl_lfsr16(value));
 139 }
 140
 141 /*
 142  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 143  * details and converts them into the DisplayLink equivalent register commands.
 144   ERR(vreg(dev,               0x00, (color_depth == 16) ? 0 : 1));
 145   ERR(vreg_lfsr16(dev,        0x01, xDisplayStart));
 146   ERR(vreg_lfsr16(dev,        0x03, xDisplayEnd));
 147   ERR(vreg_lfsr16(dev,        0x05, yDisplayStart));
 148   ERR(vreg_lfsr16(dev,        0x07, yDisplayEnd));
 149   ERR(vreg_lfsr16(dev,        0x09, xEndCount));
 150   ERR(vreg_lfsr16(dev,        0x0B, hSyncStart));
 151   ERR(vreg_lfsr16(dev,        0x0D, hSyncEnd));
 152   ERR(vreg_big_endian(dev,    0x0F, hPixels));
 153   ERR(vreg_lfsr16(dev,        0x11, yEndCount));
 154   ERR(vreg_lfsr16(dev,        0x13, vSyncStart));
 155   ERR(vreg_lfsr16(dev,        0x15, vSyncEnd));
 156   ERR(vreg_big_endian(dev,    0x17, vPixels));
 157   ERR(vreg_little_endian(dev, 0x1B, pixelClock5KHz));
 158
 159   ERR(vreg(dev,               0x1F, 0));
 160
 161   ERR(vbuf(dev, WRITE_VIDREG_UNLOCK, DSIZEOF(WRITE_VIDREG_UNLOCK)));
 162  */
 163 static char *udl_set_vid_cmds(char *wrptr, struct drm_display_mode *mode)
 164 {
 165         u16 xds, yds;
 166         u16 xde, yde;
 167         u16 yec;
 168
 169         /* x display start */
 170         xds = mode->crtc_htotal - mode->crtc_hsync_start;
 171         wrptr = udl_set_register_lfsr16(wrptr, 0x01, xds);
 172         /* x display end */
 173         xde = xds + mode->crtc_hdisplay;
 174         wrptr = udl_set_register_lfsr16(wrptr, 0x03, xde);
 175
 176         /* y display start */
 177         yds = mode->crtc_vtotal - mode->crtc_vsync_start;
 178         wrptr = udl_set_register_lfsr16(wrptr, 0x05, yds);
 179         /* y display end */
 180         yde = yds + mode->crtc_vdisplay;
 181         wrptr = udl_set_register_lfsr16(wrptr, 0x07, yde);
 182
 183         /* x end count is active + blanking - 1 */
 184         wrptr = udl_set_register_lfsr16(wrptr, 0x09,
 185                                         mode->crtc_htotal - 1);
 186
 187         /* libdlo hardcodes hsync start to 1 */
 188         wrptr = udl_set_register_lfsr16(wrptr, 0x0B, 1);
 189
 190         /* hsync end is width of sync pulse + 1 */
 191         wrptr = udl_set_register_lfsr16(wrptr, 0x0D,
 192                                         mode->crtc_hsync_end - mode->crtc_hsync_start + 1);
 193
 194         /* hpixels is active pixels */
 195         wrptr = udl_set_register_16(wrptr, 0x0F, mode->hdisplay);
 196
 197         /* yendcount is vertical active + vertical blanking */
 198         yec = mode->crtc_vtotal;
 199         wrptr = udl_set_register_lfsr16(wrptr, 0x11, yec);
 200
 201         /* libdlo hardcodes vsync start to 0 */
 202         wrptr = udl_set_register_lfsr16(wrptr, 0x13, 0);
 203
 204         /* vsync end is width of vsync pulse */
 205         wrptr = udl_set_register_lfsr16(wrptr, 0x15, mode->crtc_vsync_end - mode->crtc_vsync_start);
 206
 207         /* vpixels is active pixels */
 208         wrptr = udl_set_register_16(wrptr, 0x17, mode->crtc_vdisplay);
 209
 210         wrptr = udl_set_register_16be(wrptr, 0x1B,
 211                                       mode->clock / 5);
 212
 213         return wrptr;
 214 }
 215
 216 static char *udl_dummy_render(char *wrptr)
 217 {
 218         *wrptr++ = 0xAF;
 219         *wrptr++ = 0x6A; /* copy */
 220         *wrptr++ = 0x00; /* from addr */
 221         *wrptr++ = 0x00;
 222         *wrptr++ = 0x00;
 223         *wrptr++ = 0x01; /* one pixel */
 224         *wrptr++ = 0x00; /* to address */
 225         *wrptr++ = 0x00;
 226         *wrptr++ = 0x00;
 227         return wrptr;
 228 }
 229
 230 static int udl_crtc_write_mode_to_hw(struct drm_crtc *crtc)
 231 {
 232         struct drm_device *dev = crtc->dev;
 233         struct udl_device *udl = dev->dev_private;
 234         struct urb *urb;
 235         char *buf;
 236         int retval;
 237
 238         urb = udl_get_urb(dev);
 239         if (!urb)
 240                 return -ENOMEM;
 241
 242         buf = (char *)urb->transfer_buffer;
 243
 244         memcpy(buf, udl->mode_buf, udl->mode_buf_len);
 245         retval = udl_submit_urb(dev, urb, udl->mode_buf_len);
 246         DRM_INFO("write mode info %d\n", udl->mode_buf_len);
 247         return retval;
 248 }
 249
 250
 251 static void udl_crtc_dpms(struct drm_crtc *crtc, int mode)
 252 {
 253         struct drm_device *dev = crtc->dev;
 254         struct udl_device *udl = dev->dev_private;
 255         int retval;
 256
 257         if (mode == DRM_MODE_DPMS_OFF) {
 258                 char *buf;
 259                 struct urb *urb;
 260                 urb = udl_get_urb(dev);
 261                 if (!urb)
 262                         return;
 263
 264                 buf = (char *)urb->transfer_buffer;
 265                 buf = udl_vidreg_lock(buf);
 266                 buf = udl_set_blank(buf, mode);
 267                 buf = udl_vidreg_unlock(buf);
 268
 269                 buf = udl_dummy_render(buf);
 270                 retval = udl_submit_urb(dev, urb, buf - (char *)
 271                                         urb->transfer_buffer);
 272         } else {
 273                 if (udl->mode_buf_len == 0) {
 274                         DRM_ERROR("Trying to enable DPMS with no mode\n");
 275                         return;
 276                 }
 277                 udl_crtc_write_mode_to_hw(crtc);
 278         }
 279
 280 }
 281
 282 static bool udl_crtc_mode_fixup(struct drm_crtc *crtc,
 283                                   const struct drm_display_mode *mode,
 284                                   struct drm_display_mode *adjusted_mode)
 285
 286 {
 287         return true;
 288 }
 289
 290 #if 0
 291 static int
 292 udl_pipe_set_base_atomic(struct drm_crtc *crtc, struct drm_framebuffer *fb,
 293                            int x, int y, enum mode_set_atomic state)
 294 {
 295         return 0;
 296 }
 297
 298 static int
 299 udl_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 300                     struct drm_framebuffer *old_fb)
 301 {
 302         return 0;
 303 }
 304 #endif
 305
 306 static int udl_crtc_mode_set(struct drm_crtc *crtc,
 307                                struct drm_display_mode *mode,
 308                                struct drm_display_mode *adjusted_mode,
 309                                int x, int y,
 310                                struct drm_framebuffer *old_fb)
 311
 312 {
 313         struct drm_device *dev = crtc->dev;
 314         struct udl_framebuffer *ufb = to_udl_fb(crtc->primary->fb);
 315         struct udl_device *udl = dev->dev_private;
 316         char *buf;
 317         char *wrptr;
 318         int color_depth = 0;
 319
 320         buf = (char *)udl->mode_buf;
 321
 322         /* for now we just clip 24 -> 16 - if we fix that fix this */
 323         /*if  (crtc->fb->bits_per_pixel != 16)
 324           color_depth = 1; */
 325
 326         /* This first section has to do with setting the base address on the
 327         * controller * associated with the display. There are 2 base
 328         * pointers, currently, we only * use the 16 bpp segment.
 329         */
 330         wrptr = udl_vidreg_lock(buf);
 331         wrptr = udl_set_color_depth(wrptr, color_depth);
 332         /* set base for 16bpp segment to 0 */
 333         wrptr = udl_set_base16bpp(wrptr, 0);
 334         /* set base for 8bpp segment to end of fb */
 335         wrptr = udl_set_base8bpp(wrptr, 2 * mode->vdisplay * mode->hdisplay);
 336
 337         wrptr = udl_set_vid_cmds(wrptr, adjusted_mode);
 338         wrptr = udl_set_blank(wrptr, DRM_MODE_DPMS_ON);
 339         wrptr = udl_vidreg_unlock(wrptr);
 340
 341         wrptr = udl_dummy_render(wrptr);
 342
 343         if (old_fb) {
 344                 struct udl_framebuffer *uold_fb = to_udl_fb(old_fb);
 345                 uold_fb->active_16 = false;
 346         }
 347         ufb->active_16 = true;
 348         udl->mode_buf_len = wrptr - buf;
 349
 350         /* damage all of it */
 351         udl_handle_damage(ufb, 0, 0, ufb->base.width, ufb->base.height);
 352         return 0;
 353 }
 354
 355
 356 static void udl_crtc_disable(struct drm_crtc *crtc)
 357 {
 358         udl_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 359 }
 360
 361 static void udl_crtc_destroy(struct drm_crtc *crtc)
 362 {
 363         drm_crtc_cleanup(crtc);
 364         kfree(crtc);
 365 }
 366
 367 static int udl_crtc_page_flip(struct drm_crtc *crtc,
 368                               struct drm_framebuffer *fb,
 369                               struct drm_pending_vblank_event *event,
 370                               uint32_t page_flip_flags)
 371 {
 372         struct udl_framebuffer *ufb = to_udl_fb(fb);
 373         struct drm_device *dev = crtc->dev;
 374         unsigned long flags;
 375
 376         struct drm_framebuffer *old_fb = crtc->primary->fb;
 377         if (old_fb) {
 378                 struct udl_framebuffer *uold_fb = to_udl_fb(old_fb);
 379                 uold_fb->active_16 = false;
 380         }
 381         ufb->active_16 = true;
 382
 383         udl_handle_damage(ufb, 0, 0, fb->width, fb->height);
 384
 385         spin_lock_irqsave(&dev->event_lock, flags);
 386         if (event)
 387                 drm_send_vblank_event(dev, 0, event);
 388         spin_unlock_irqrestore(&dev->event_lock, flags);
 389         crtc->primary->fb = fb;
 390
 391         return 0;
 392 }
 393
 394 static void udl_crtc_prepare(struct drm_crtc *crtc)
 395 {
 396 }
 397
 398 static void udl_crtc_commit(struct drm_crtc *crtc)
 399 {
 400         udl_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
 401 }
 402
 403 static struct drm_crtc_helper_funcs udl_helper_funcs = {
 404         .dpms = udl_crtc_dpms,
 405         .mode_fixup = udl_crtc_mode_fixup,
 406         .mode_set = udl_crtc_mode_set,
 407         .prepare = udl_crtc_prepare,
 408         .commit = udl_crtc_commit,
 409         .disable = udl_crtc_disable,
 410 };
 411
 412 static const struct drm_crtc_funcs udl_crtc_funcs = {
 413         .set_config = drm_crtc_helper_set_config,
 414         .destroy = udl_crtc_destroy,
 415         .page_flip = udl_crtc_page_flip,
 416 };
 417
 418 static int udl_crtc_init(struct drm_device *dev)
 419 {
 420         struct drm_crtc *crtc;
 421
 422         crtc = kzalloc(sizeof(struct drm_crtc) + sizeof(struct drm_connector *), GFP_KERNEL);
 423         if (crtc == NULL)
 424                 return -ENOMEM;
 425
 426         drm_crtc_init(dev, crtc, &udl_crtc_funcs);
 427         drm_crtc_helper_add(crtc, &udl_helper_funcs);
 428
 429         return 0;
 430 }
 431
 432 static const struct drm_mode_config_funcs udl_mode_funcs = {
 433         .fb_create = udl_fb_user_fb_create,
 434         .output_poll_changed = NULL,
 435 };
 436
 437 int udl_modeset_init(struct drm_device *dev)
 438 {
 439         struct drm_encoder *encoder;
 440         drm_mode_config_init(dev);
 441
 442         dev->mode_config.min_width = 640;
 443         dev->mode_config.min_height = 480;
 444
 445         dev->mode_config.max_width = 2048;
 446         dev->mode_config.max_height = 2048;
 447
 448         dev->mode_config.prefer_shadow = 0;
 449         dev->mode_config.preferred_depth = 24;
 450
 451         dev->mode_config.funcs = &udl_mode_funcs;
 452
 453         drm_mode_create_dirty_info_property(dev);
 454
 455         udl_crtc_init(dev);
 456
 457         encoder = udl_encoder_init(dev);
 458
 459         udl_connector_init(dev, encoder);
 460
 461         return 0;
 462 }
 463
 464 void udl_modeset_cleanup(struct drm_device *dev)
 465 {
 466         drm_mode_config_cleanup(dev);
 467 }