drivers/staging/fbtft/fbtft-core.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2013 Noralf Tronnes
   4  *
   5  * This driver is inspired by:
   6  *   st7735fb.c, Copyright (C) 2011, Matt Porter
   7  *   broadsheetfb.c, Copyright (C) 2008, Jaya Kumar
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/mm.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/slab.h>
  17 #include <linux/init.h>
  18 #include <linux/fb.h>
  19 #include <linux/gpio/consumer.h>
  20 #include <linux/spi/spi.h>
  21 #include <linux/delay.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/backlight.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/property.h>
  26 #include <linux/spinlock.h>
  27
  28 #include <video/mipi_display.h>
  29
  30 #include "fbtft.h"
  31 #include "internal.h"
  32
  33 static unsigned long debug;
  34 module_param(debug, ulong, 0000);
  35 MODULE_PARM_DESC(debug, "override device debug level");
  36
  37 int fbtft_write_buf_dc(struct fbtft_par *par, void *buf, size_t len, int dc)
  38 {
  39         int ret;
  40
  41         if (par->gpio.dc)
  42                 gpiod_set_value(par->gpio.dc, dc);
  43
  44         ret = par->fbtftops.write(par, buf, len);
  45         if (ret < 0)
  46                 dev_err(par->info->device,
  47                         "write() failed and returned %d\n", ret);
  48         return ret;
  49 }
  50 EXPORT_SYMBOL(fbtft_write_buf_dc);
  51
  52 void fbtft_dbg_hex(const struct device *dev, int groupsize,
  53                    void *buf, size_t len, const char *fmt, ...)
  54 {
  55         va_list args;
  56         static char textbuf[512];
  57         char *text = textbuf;
  58         size_t text_len;
  59
  60         va_start(args, fmt);
  61         text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
  62         va_end(args);
  63
  64         hex_dump_to_buffer(buf, len, 32, groupsize, text + text_len,
  65                            512 - text_len, false);
  66
  67         if (len > 32)
  68                 dev_info(dev, "%s ...\n", text);
  69         else
  70                 dev_info(dev, "%s\n", text);
  71 }
  72 EXPORT_SYMBOL(fbtft_dbg_hex);
  73
  74 static int fbtft_request_one_gpio(struct fbtft_par *par,
  75                                   const char *name, int index,
  76                                   struct gpio_desc **gpiop)
  77 {
  78         struct device *dev = par->info->device;
  79         int ret = 0;
  80
  81         *gpiop = devm_gpiod_get_index_optional(dev, name, index,
  82                                                GPIOD_OUT_HIGH);
  83         if (IS_ERR(*gpiop)) {
  84                 ret = PTR_ERR(*gpiop);
  85                 dev_err(dev,
  86                         "Failed to request %s GPIO: %d\n", name, ret);
  87                 return ret;
  88         }
  89         fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO\n",
  90                       __func__, name);
  91
  92         return ret;
  93 }
  94
  95 static int fbtft_request_gpios(struct fbtft_par *par)
  96 {
  97         int i;
  98         int ret;
  99
 100         ret = fbtft_request_one_gpio(par, "reset", 0, &par->gpio.reset);
 101         if (ret)
 102                 return ret;
 103         ret = fbtft_request_one_gpio(par, "dc", 0, &par->gpio.dc);
 104         if (ret)
 105                 return ret;
 106         ret = fbtft_request_one_gpio(par, "rd", 0, &par->gpio.rd);
 107         if (ret)
 108                 return ret;
 109         ret = fbtft_request_one_gpio(par, "wr", 0, &par->gpio.wr);
 110         if (ret)
 111                 return ret;
 112         ret = fbtft_request_one_gpio(par, "cs", 0, &par->gpio.cs);
 113         if (ret)
 114                 return ret;
 115         ret = fbtft_request_one_gpio(par, "latch", 0, &par->gpio.latch);
 116         if (ret)
 117                 return ret;
 118         for (i = 0; i < 16; i++) {
 119                 ret = fbtft_request_one_gpio(par, "db", i,
 120                                              &par->gpio.db[i]);
 121                 if (ret)
 122                         return ret;
 123                 ret = fbtft_request_one_gpio(par, "led", i,
 124                                              &par->gpio.led[i]);
 125                 if (ret)
 126                         return ret;
 127                 ret = fbtft_request_one_gpio(par, "aux", i,
 128                                              &par->gpio.aux[i]);
 129                 if (ret)
 130                         return ret;
 131         }
 132
 133         return 0;
 134 }
 135
 136 #ifdef CONFIG_FB_BACKLIGHT
 137 static int fbtft_backlight_update_status(struct backlight_device *bd)
 138 {
 139         struct fbtft_par *par = bl_get_data(bd);
 140         bool polarity = par->polarity;
 141
 142         fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 143                       "%s: polarity=%d, power=%d, fb_blank=%d\n",
 144                       __func__, polarity, bd->props.power, bd->props.fb_blank);
 145
 146         if ((bd->props.power == FB_BLANK_UNBLANK) &&
 147             (bd->props.fb_blank == FB_BLANK_UNBLANK))
 148                 gpiod_set_value(par->gpio.led[0], polarity);
 149         else
 150                 gpiod_set_value(par->gpio.led[0], !polarity);
 151
 152         return 0;
 153 }
 154
 155 static int fbtft_backlight_get_brightness(struct backlight_device *bd)
 156 {
 157         return bd->props.brightness;
 158 }
 159
 160 void fbtft_unregister_backlight(struct fbtft_par *par)
 161 {
 162         if (par->info->bl_dev) {
 163                 par->info->bl_dev->props.power = FB_BLANK_POWERDOWN;
 164                 backlight_update_status(par->info->bl_dev);
 165                 backlight_device_unregister(par->info->bl_dev);
 166                 par->info->bl_dev = NULL;
 167         }
 168 }
 169
 170 static const struct backlight_ops fbtft_bl_ops = {
 171         .get_brightness = fbtft_backlight_get_brightness,
 172         .update_status  = fbtft_backlight_update_status,
 173 };
 174
 175 void fbtft_register_backlight(struct fbtft_par *par)
 176 {
 177         struct backlight_device *bd;
 178         struct backlight_properties bl_props = { 0, };
 179
 180         if (!par->gpio.led[0]) {
 181                 fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 182                               "%s(): led pin not set, exiting.\n", __func__);
 183                 return;
 184         }
 185
 186         bl_props.type = BACKLIGHT_RAW;
 187         /* Assume backlight is off, get polarity from current state of pin */
 188         bl_props.power = FB_BLANK_POWERDOWN;
 189         if (!gpiod_get_value(par->gpio.led[0]))
 190                 par->polarity = true;
 191
 192         bd = backlight_device_register(dev_driver_string(par->info->device),
 193                                        par->info->device, par,
 194                                        &fbtft_bl_ops, &bl_props);
 195         if (IS_ERR(bd)) {
 196                 dev_err(par->info->device,
 197                         "cannot register backlight device (%ld)\n",
 198                         PTR_ERR(bd));
 199                 return;
 200         }
 201         par->info->bl_dev = bd;
 202
 203         if (!par->fbtftops.unregister_backlight)
 204                 par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
 205 }
 206 #else
 207 void fbtft_register_backlight(struct fbtft_par *par) { };
 208 void fbtft_unregister_backlight(struct fbtft_par *par) { };
 209 #endif
 210 EXPORT_SYMBOL(fbtft_register_backlight);
 211 EXPORT_SYMBOL(fbtft_unregister_backlight);
 212
 213 static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
 214                                int ye)
 215 {
 216         write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
 217                   (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
 218
 219         write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
 220                   (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
 221
 222         write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
 223 }
 224
 225 static void fbtft_reset(struct fbtft_par *par)
 226 {
 227         if (!par->gpio.reset)
 228                 return;
 229         fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
 230         gpiod_set_value_cansleep(par->gpio.reset, 1);
 231         usleep_range(20, 40);
 232         gpiod_set_value_cansleep(par->gpio.reset, 0);
 233         msleep(120);
 234 }
 235
 236 static void fbtft_update_display(struct fbtft_par *par, unsigned int start_line,
 237                                  unsigned int end_line)
 238 {
 239         size_t offset, len;
 240         ktime_t ts_start, ts_end;
 241         long fps, throughput;
 242         bool timeit = false;
 243         int ret = 0;
 244
 245         if (unlikely(par->debug & (DEBUG_TIME_FIRST_UPDATE |
 246                         DEBUG_TIME_EACH_UPDATE))) {
 247                 if ((par->debug & DEBUG_TIME_EACH_UPDATE) ||
 248                     ((par->debug & DEBUG_TIME_FIRST_UPDATE) &&
 249                     !par->first_update_done)) {
 250                         ts_start = ktime_get();
 251                         timeit = true;
 252                 }
 253         }
 254
 255         /* Sanity checks */
 256         if (start_line > end_line) {
 257                 dev_warn(par->info->device,
 258                          "%s: start_line=%u is larger than end_line=%u. Shouldn't happen, will do full display update\n",
 259                          __func__, start_line, end_line);
 260                 start_line = 0;
 261                 end_line = par->info->var.yres - 1;
 262         }
 263         if (start_line > par->info->var.yres - 1 ||
 264             end_line > par->info->var.yres - 1) {
 265                 dev_warn(par->info->device,
 266                          "%s: start_line=%u or end_line=%u is larger than max=%d. Shouldn't happen, will do full display update\n",
 267                          __func__, start_line,
 268                          end_line, par->info->var.yres - 1);
 269                 start_line = 0;
 270                 end_line = par->info->var.yres - 1;
 271         }
 272
 273         fbtft_par_dbg(DEBUG_UPDATE_DISPLAY, par, "%s(start_line=%u, end_line=%u)\n",
 274                       __func__, start_line, end_line);
 275
 276         if (par->fbtftops.set_addr_win)
 277                 par->fbtftops.set_addr_win(par, 0, start_line,
 278                                 par->info->var.xres - 1, end_line);
 279
 280         offset = start_line * par->info->fix.line_length;
 281         len = (end_line - start_line + 1) * par->info->fix.line_length;
 282         ret = par->fbtftops.write_vmem(par, offset, len);
 283         if (ret < 0)
 284                 dev_err(par->info->device,
 285                         "%s: write_vmem failed to update display buffer\n",
 286                         __func__);
 287
 288         if (unlikely(timeit)) {
 289                 ts_end = ktime_get();
 290                 if (!ktime_to_ns(par->update_time))
 291                         par->update_time = ts_start;
 292
 293                 fps = ktime_us_delta(ts_start, par->update_time);
 294                 par->update_time = ts_start;
 295                 fps = fps ? 1000000 / fps : 0;
 296
 297                 throughput = ktime_us_delta(ts_end, ts_start);
 298                 throughput = throughput ? (len * 1000) / throughput : 0;
 299                 throughput = throughput * 1000 / 1024;
 300
 301                 dev_info(par->info->device,
 302                          "Display update: %ld kB/s, fps=%ld\n",
 303                          throughput, fps);
 304                 par->first_update_done = true;
 305         }
 306 }
 307
 308 static void fbtft_mkdirty(struct fb_info *info, int y, int height)
 309 {
 310         struct fbtft_par *par = info->par;
 311         struct fb_deferred_io *fbdefio = info->fbdefio;
 312
 313         /* special case, needed ? */
 314         if (y == -1) {
 315                 y = 0;
 316                 height = info->var.yres;
 317         }
 318
 319         /* Mark display lines/area as dirty */
 320         spin_lock(&par->dirty_lock);
 321         if (y < par->dirty_lines_start)
 322                 par->dirty_lines_start = y;
 323         if (y + height - 1 > par->dirty_lines_end)
 324                 par->dirty_lines_end = y + height - 1;
 325         spin_unlock(&par->dirty_lock);
 326
 327         /* Schedule deferred_io to update display (no-op if already on queue)*/
 328         schedule_delayed_work(&info->deferred_work, fbdefio->delay);
 329 }
 330
 331 static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagelist)
 332 {
 333         struct fbtft_par *par = info->par;
 334         unsigned int dirty_lines_start, dirty_lines_end;
 335         struct page *page;
 336         unsigned long index;
 337         unsigned int y_low = 0, y_high = 0;
 338         int count = 0;
 339
 340         spin_lock(&par->dirty_lock);
 341         dirty_lines_start = par->dirty_lines_start;
 342         dirty_lines_end = par->dirty_lines_end;
 343         /* set display line markers as clean */
 344         par->dirty_lines_start = par->info->var.yres - 1;
 345         par->dirty_lines_end = 0;
 346         spin_unlock(&par->dirty_lock);
 347
 348         /* Mark display lines as dirty */
 349         list_for_each_entry(page, pagelist, lru) {
 350                 count++;
 351                 index = page->index << PAGE_SHIFT;
 352                 y_low = index / info->fix.line_length;
 353                 y_high = (index + PAGE_SIZE - 1) / info->fix.line_length;
 354                 dev_dbg(info->device,
 355                         "page->index=%lu y_low=%d y_high=%d\n",
 356                         page->index, y_low, y_high);
 357                 if (y_high > info->var.yres - 1)
 358                         y_high = info->var.yres - 1;
 359                 if (y_low < dirty_lines_start)
 360                         dirty_lines_start = y_low;
 361                 if (y_high > dirty_lines_end)
 362                         dirty_lines_end = y_high;
 363         }
 364
 365         par->fbtftops.update_display(info->par,
 366                                         dirty_lines_start, dirty_lines_end);
 367 }
 368
 369 static void fbtft_fb_fillrect(struct fb_info *info,
 370                               const struct fb_fillrect *rect)
 371 {
 372         struct fbtft_par *par = info->par;
 373
 374         dev_dbg(info->dev,
 375                 "%s: dx=%d, dy=%d, width=%d, height=%d\n",
 376                 __func__, rect->dx, rect->dy, rect->width, rect->height);
 377         sys_fillrect(info, rect);
 378
 379         par->fbtftops.mkdirty(info, rect->dy, rect->height);
 380 }
 381
 382 static void fbtft_fb_copyarea(struct fb_info *info,
 383                               const struct fb_copyarea *area)
 384 {
 385         struct fbtft_par *par = info->par;
 386
 387         dev_dbg(info->dev,
 388                 "%s: dx=%d, dy=%d, width=%d, height=%d\n",
 389                 __func__,  area->dx, area->dy, area->width, area->height);
 390         sys_copyarea(info, area);
 391
 392         par->fbtftops.mkdirty(info, area->dy, area->height);
 393 }
 394
 395 static void fbtft_fb_imageblit(struct fb_info *info,
 396                                const struct fb_image *image)
 397 {
 398         struct fbtft_par *par = info->par;
 399
 400         dev_dbg(info->dev,
 401                 "%s: dx=%d, dy=%d, width=%d, height=%d\n",
 402                 __func__,  image->dx, image->dy, image->width, image->height);
 403         sys_imageblit(info, image);
 404
 405         par->fbtftops.mkdirty(info, image->dy, image->height);
 406 }
 407
 408 static ssize_t fbtft_fb_write(struct fb_info *info, const char __user *buf,
 409                               size_t count, loff_t *ppos)
 410 {
 411         struct fbtft_par *par = info->par;
 412         ssize_t res;
 413
 414         dev_dbg(info->dev,
 415                 "%s: count=%zd, ppos=%llu\n", __func__,  count, *ppos);
 416         res = fb_sys_write(info, buf, count, ppos);
 417
 418         /* TODO: only mark changed area update all for now */
 419         par->fbtftops.mkdirty(info, -1, 0);
 420
 421         return res;
 422 }
 423
 424 /* from pxafb.c */
 425 static unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf)
 426 {
 427         chan &= 0xffff;
 428         chan >>= 16 - bf->length;
 429         return chan << bf->offset;
 430 }
 431
 432 static int fbtft_fb_setcolreg(unsigned int regno, unsigned int red,
 433                               unsigned int green, unsigned int blue,
 434                               unsigned int transp, struct fb_info *info)
 435 {
 436         unsigned int val;
 437         int ret = 1;
 438
 439         dev_dbg(info->dev,
 440                 "%s(regno=%u, red=0x%X, green=0x%X, blue=0x%X, trans=0x%X)\n",
 441                 __func__, regno, red, green, blue, transp);
 442
 443         switch (info->fix.visual) {
 444         case FB_VISUAL_TRUECOLOR:
 445                 if (regno < 16) {
 446                         u32 *pal = info->pseudo_palette;
 447
 448                         val  = chan_to_field(red,   &info->var.red);
 449                         val |= chan_to_field(green, &info->var.green);
 450                         val |= chan_to_field(blue,  &info->var.blue);
 451
 452                         pal[regno] = val;
 453                         ret = 0;
 454                 }
 455                 break;
 456         }
 457         return ret;
 458 }
 459
 460 static int fbtft_fb_blank(int blank, struct fb_info *info)
 461 {
 462         struct fbtft_par *par = info->par;
 463         int ret = -EINVAL;
 464
 465         dev_dbg(info->dev, "%s(blank=%d)\n",
 466                 __func__, blank);
 467
 468         if (!par->fbtftops.blank)
 469                 return ret;
 470
 471         switch (blank) {
 472         case FB_BLANK_POWERDOWN:
 473         case FB_BLANK_VSYNC_SUSPEND:
 474         case FB_BLANK_HSYNC_SUSPEND:
 475         case FB_BLANK_NORMAL:
 476                 ret = par->fbtftops.blank(par, true);
 477                 break;
 478         case FB_BLANK_UNBLANK:
 479                 ret = par->fbtftops.blank(par, false);
 480                 break;
 481         }
 482         return ret;
 483 }
 484
 485 static void fbtft_merge_fbtftops(struct fbtft_ops *dst, struct fbtft_ops *src)
 486 {
 487         if (src->write)
 488                 dst->write = src->write;
 489         if (src->read)
 490                 dst->read = src->read;
 491         if (src->write_vmem)
 492                 dst->write_vmem = src->write_vmem;
 493         if (src->write_register)
 494                 dst->write_register = src->write_register;
 495         if (src->set_addr_win)
 496                 dst->set_addr_win = src->set_addr_win;
 497         if (src->reset)
 498                 dst->reset = src->reset;
 499         if (src->mkdirty)
 500                 dst->mkdirty = src->mkdirty;
 501         if (src->update_display)
 502                 dst->update_display = src->update_display;
 503         if (src->init_display)
 504                 dst->init_display = src->init_display;
 505         if (src->blank)
 506                 dst->blank = src->blank;
 507         if (src->request_gpios_match)
 508                 dst->request_gpios_match = src->request_gpios_match;
 509         if (src->request_gpios)
 510                 dst->request_gpios = src->request_gpios;
 511         if (src->verify_gpios)
 512                 dst->verify_gpios = src->verify_gpios;
 513         if (src->register_backlight)
 514                 dst->register_backlight = src->register_backlight;
 515         if (src->unregister_backlight)
 516                 dst->unregister_backlight = src->unregister_backlight;
 517         if (src->set_var)
 518                 dst->set_var = src->set_var;
 519         if (src->set_gamma)
 520                 dst->set_gamma = src->set_gamma;
 521 }
 522
 523 /**
 524  * fbtft_framebuffer_alloc - creates a new frame buffer info structure
 525  *
 526  * @display: pointer to structure describing the display
 527  * @dev: pointer to the device for this fb, this can be NULL
 528  * @pdata: platform data for the display in use
 529  *
 530  * Creates a new frame buffer info structure.
 531  *
 532  * Also creates and populates the following structures:
 533  *   info->fbops
 534  *   info->fbdefio
 535  *   info->pseudo_palette
 536  *   par->fbtftops
 537  *   par->txbuf
 538  *
 539  * Returns the new structure, or NULL if an error occurred.
 540  *
 541  */
 542 struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 543                                         struct device *dev,
 544                                         struct fbtft_platform_data *pdata)
 545 {
 546         struct fb_info *info;
 547         struct fbtft_par *par;
 548         struct fb_ops *fbops = NULL;
 549         struct fb_deferred_io *fbdefio = NULL;
 550         u8 *vmem = NULL;
 551         void *txbuf = NULL;
 552         void *buf = NULL;
 553         unsigned int width;
 554         unsigned int height;
 555         int txbuflen = display->txbuflen;
 556         unsigned int bpp = display->bpp;
 557         unsigned int fps = display->fps;
 558         int vmem_size;
 559         const s16 *init_sequence = display->init_sequence;
 560         char *gamma = display->gamma;
 561         u32 *gamma_curves = NULL;
 562
 563         /* sanity check */
 564         if (display->gamma_num * display->gamma_len >
 565                         FBTFT_GAMMA_MAX_VALUES_TOTAL) {
 566                 dev_err(dev, "FBTFT_GAMMA_MAX_VALUES_TOTAL=%d is exceeded\n",
 567                         FBTFT_GAMMA_MAX_VALUES_TOTAL);
 568                 return NULL;
 569         }
 570
 571         /* defaults */
 572         if (!fps)
 573                 fps = 20;
 574         if (!bpp)
 575                 bpp = 16;
 576
 577         if (!pdata) {
 578                 dev_err(dev, "platform data is missing\n");
 579                 return NULL;
 580         }
 581
 582         /* override driver values? */
 583         if (pdata->fps)
 584                 fps = pdata->fps;
 585         if (pdata->txbuflen)
 586                 txbuflen = pdata->txbuflen;
 587         if (pdata->display.init_sequence)
 588                 init_sequence = pdata->display.init_sequence;
 589         if (pdata->gamma)
 590                 gamma = pdata->gamma;
 591         if (pdata->display.debug)
 592                 display->debug = pdata->display.debug;
 593         if (pdata->display.backlight)
 594                 display->backlight = pdata->display.backlight;
 595         if (pdata->display.width)
 596                 display->width = pdata->display.width;
 597         if (pdata->display.height)
 598                 display->height = pdata->display.height;
 599         if (pdata->display.buswidth)
 600                 display->buswidth = pdata->display.buswidth;
 601         if (pdata->display.regwidth)
 602                 display->regwidth = pdata->display.regwidth;
 603
 604         display->debug |= debug;
 605         fbtft_expand_debug_value(&display->debug);
 606
 607         switch (pdata->rotate) {
 608         case 90:
 609         case 270:
 610                 width =  display->height;
 611                 height = display->width;
 612                 break;
 613         default:
 614                 width =  display->width;
 615                 height = display->height;
 616         }
 617
 618         vmem_size = display->width * display->height * bpp / 8;
 619         vmem = vzalloc(vmem_size);
 620         if (!vmem)
 621                 goto alloc_fail;
 622
 623         fbops = devm_kzalloc(dev, sizeof(struct fb_ops), GFP_KERNEL);
 624         if (!fbops)
 625                 goto alloc_fail;
 626
 627         fbdefio = devm_kzalloc(dev, sizeof(struct fb_deferred_io), GFP_KERNEL);
 628         if (!fbdefio)
 629                 goto alloc_fail;
 630
 631         buf = devm_kzalloc(dev, 128, GFP_KERNEL);
 632         if (!buf)
 633                 goto alloc_fail;
 634
 635         if (display->gamma_num && display->gamma_len) {
 636                 gamma_curves = devm_kcalloc(dev,
 637                                             display->gamma_num *
 638                                             display->gamma_len,
 639                                             sizeof(gamma_curves[0]),
 640                                             GFP_KERNEL);
 641                 if (!gamma_curves)
 642                         goto alloc_fail;
 643         }
 644
 645         info = framebuffer_alloc(sizeof(struct fbtft_par), dev);
 646         if (!info)
 647                 goto alloc_fail;
 648
 649         info->screen_buffer = vmem;
 650         info->fbops = fbops;
 651         info->fbdefio = fbdefio;
 652
 653         fbops->owner        =      dev->driver->owner;
 654         fbops->fb_read      =      fb_sys_read;
 655         fbops->fb_write     =      fbtft_fb_write;
 656         fbops->fb_fillrect  =      fbtft_fb_fillrect;
 657         fbops->fb_copyarea  =      fbtft_fb_copyarea;
 658         fbops->fb_imageblit =      fbtft_fb_imageblit;
 659         fbops->fb_setcolreg =      fbtft_fb_setcolreg;
 660         fbops->fb_blank     =      fbtft_fb_blank;
 661
 662         fbdefio->delay =           HZ / fps;
 663         fbdefio->deferred_io =     fbtft_deferred_io;
 664         fb_deferred_io_init(info);
 665
 666         snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
 667         info->fix.type =           FB_TYPE_PACKED_PIXELS;
 668         info->fix.visual =         FB_VISUAL_TRUECOLOR;
 669         info->fix.xpanstep =       0;
 670         info->fix.ypanstep =       0;
 671         info->fix.ywrapstep =      0;
 672         info->fix.line_length =    width * bpp / 8;
 673         info->fix.accel =          FB_ACCEL_NONE;
 674         info->fix.smem_len =       vmem_size;
 675
 676         info->var.rotate =         pdata->rotate;
 677         info->var.xres =           width;
 678         info->var.yres =           height;
 679         info->var.xres_virtual =   info->var.xres;
 680         info->var.yres_virtual =   info->var.yres;
 681         info->var.bits_per_pixel = bpp;
 682         info->var.nonstd =         1;
 683
 684         /* RGB565 */
 685         info->var.red.offset =     11;
 686         info->var.red.length =     5;
 687         info->var.green.offset =   5;
 688         info->var.green.length =   6;
 689         info->var.blue.offset =    0;
 690         info->var.blue.length =    5;
 691         info->var.transp.offset =  0;
 692         info->var.transp.length =  0;
 693
 694         info->flags =              FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
 695
 696         par = info->par;
 697         par->info = info;
 698         par->pdata = pdata;
 699         par->debug = display->debug;
 700         par->buf = buf;
 701         spin_lock_init(&par->dirty_lock);
 702         par->bgr = pdata->bgr;
 703         par->startbyte = pdata->startbyte;
 704         par->init_sequence = init_sequence;
 705         par->gamma.curves = gamma_curves;
 706         par->gamma.num_curves = display->gamma_num;
 707         par->gamma.num_values = display->gamma_len;
 708         mutex_init(&par->gamma.lock);
 709         info->pseudo_palette = par->pseudo_palette;
 710
 711         if (par->gamma.curves && gamma) {
 712                 if (fbtft_gamma_parse_str(par, par->gamma.curves, gamma,
 713                                           strlen(gamma)))
 714                         goto release_framebuf;
 715         }
 716
 717         /* Transmit buffer */
 718         if (txbuflen == -1)
 719                 txbuflen = vmem_size + 2; /* add in case startbyte is used */
 720         if (txbuflen >= vmem_size + 2)
 721                 txbuflen = 0;
 722
 723 #ifdef __LITTLE_ENDIAN
 724         if ((!txbuflen) && (bpp > 8))
 725                 txbuflen = PAGE_SIZE; /* need buffer for byteswapping */
 726 #endif
 727
 728         if (txbuflen > 0) {
 729                 txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
 730                 if (!txbuf)
 731                         goto release_framebuf;
 732                 par->txbuf.buf = txbuf;
 733                 par->txbuf.len = txbuflen;
 734         }
 735
 736         /* default fbtft operations */
 737         par->fbtftops.write = fbtft_write_spi;
 738         par->fbtftops.read = fbtft_read_spi;
 739         par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
 740         par->fbtftops.write_register = fbtft_write_reg8_bus8;
 741         par->fbtftops.set_addr_win = fbtft_set_addr_win;
 742         par->fbtftops.reset = fbtft_reset;
 743         par->fbtftops.mkdirty = fbtft_mkdirty;
 744         par->fbtftops.update_display = fbtft_update_display;
 745         if (display->backlight)
 746                 par->fbtftops.register_backlight = fbtft_register_backlight;
 747
 748         /* use driver provided functions */
 749         fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
 750
 751         return info;
 752
 753 release_framebuf:
 754         framebuffer_release(info);
 755
 756 alloc_fail:
 757         vfree(vmem);
 758
 759         return NULL;
 760 }
 761 EXPORT_SYMBOL(fbtft_framebuffer_alloc);
 762
 763 /**
 764  * fbtft_framebuffer_release - frees up all memory used by the framebuffer
 765  *
 766  * @info: frame buffer info structure
 767  *
 768  */
 769 void fbtft_framebuffer_release(struct fb_info *info)
 770 {
 771         fb_deferred_io_cleanup(info);
 772         vfree(info->screen_buffer);
 773         framebuffer_release(info);
 774 }
 775 EXPORT_SYMBOL(fbtft_framebuffer_release);
 776
 777 /**
 778  *      fbtft_register_framebuffer - registers a tft frame buffer device
 779  *      @fb_info: frame buffer info structure
 780  *
 781  *  Sets SPI driverdata if needed
 782  *  Requests needed gpios.
 783  *  Initializes display
 784  *  Updates display.
 785  *      Registers a frame buffer device @fb_info.
 786  *
 787  *      Returns negative errno on error, or zero for success.
 788  *
 789  */
 790 int fbtft_register_framebuffer(struct fb_info *fb_info)
 791 {
 792         int ret;
 793         char text1[50] = "";
 794         char text2[50] = "";
 795         struct fbtft_par *par = fb_info->par;
 796         struct spi_device *spi = par->spi;
 797
 798         /* sanity checks */
 799         if (!par->fbtftops.init_display) {
 800                 dev_err(fb_info->device, "missing fbtftops.init_display()\n");
 801                 return -EINVAL;
 802         }
 803
 804         if (spi)
 805                 spi_set_drvdata(spi, fb_info);
 806         if (par->pdev)
 807                 platform_set_drvdata(par->pdev, fb_info);
 808
 809         ret = par->fbtftops.request_gpios(par);
 810         if (ret < 0)
 811                 goto reg_fail;
 812
 813         if (par->fbtftops.verify_gpios) {
 814                 ret = par->fbtftops.verify_gpios(par);
 815                 if (ret < 0)
 816                         goto reg_fail;
 817         }
 818
 819         ret = par->fbtftops.init_display(par);
 820         if (ret < 0)
 821                 goto reg_fail;
 822         if (par->fbtftops.set_var) {
 823                 ret = par->fbtftops.set_var(par);
 824                 if (ret < 0)
 825                         goto reg_fail;
 826         }
 827
 828         /* update the entire display */
 829         par->fbtftops.update_display(par, 0, par->info->var.yres - 1);
 830
 831         if (par->fbtftops.set_gamma && par->gamma.curves) {
 832                 ret = par->fbtftops.set_gamma(par, par->gamma.curves);
 833                 if (ret)
 834                         goto reg_fail;
 835         }
 836
 837         if (par->fbtftops.register_backlight)
 838                 par->fbtftops.register_backlight(par);
 839
 840         ret = register_framebuffer(fb_info);
 841         if (ret < 0)
 842                 goto reg_fail;
 843
 844         fbtft_sysfs_init(par);
 845
 846         if (par->txbuf.buf && par->txbuf.len >= 1024)
 847                 sprintf(text1, ", %zu KiB buffer memory", par->txbuf.len >> 10);
 848         if (spi)
 849                 sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
 850                         spi->chip_select, spi->max_speed_hz / 1000000);
 851         dev_info(fb_info->dev,
 852                  "%s frame buffer, %dx%d, %d KiB video memory%s, fps=%lu%s\n",
 853                  fb_info->fix.id, fb_info->var.xres, fb_info->var.yres,
 854                  fb_info->fix.smem_len >> 10, text1,
 855                  HZ / fb_info->fbdefio->delay, text2);
 856
 857 #ifdef CONFIG_FB_BACKLIGHT
 858         /* Turn on backlight if available */
 859         if (fb_info->bl_dev) {
 860                 fb_info->bl_dev->props.power = FB_BLANK_UNBLANK;
 861                 fb_info->bl_dev->ops->update_status(fb_info->bl_dev);
 862         }
 863 #endif
 864
 865         return 0;
 866
 867 reg_fail:
 868         if (par->fbtftops.unregister_backlight)
 869                 par->fbtftops.unregister_backlight(par);
 870
 871         return ret;
 872 }
 873 EXPORT_SYMBOL(fbtft_register_framebuffer);
 874
 875 /**
 876  *      fbtft_unregister_framebuffer - releases a tft frame buffer device
 877  *      @fb_info: frame buffer info structure
 878  *
 879  *  Frees SPI driverdata if needed
 880  *  Frees gpios.
 881  *      Unregisters frame buffer device.
 882  *
 883  */
 884 int fbtft_unregister_framebuffer(struct fb_info *fb_info)
 885 {
 886         struct fbtft_par *par = fb_info->par;
 887
 888         if (par->fbtftops.unregister_backlight)
 889                 par->fbtftops.unregister_backlight(par);
 890         fbtft_sysfs_exit(par);
 891         unregister_framebuffer(fb_info);
 892
 893         return 0;
 894 }
 895 EXPORT_SYMBOL(fbtft_unregister_framebuffer);
 896
 897 /**
 898  * fbtft_init_display_from_property() - Device Tree init_display() function
 899  * @par: Driver data
 900  *
 901  * Return: 0 if successful, negative if error
 902  */
 903 static int fbtft_init_display_from_property(struct fbtft_par *par)
 904 {
 905         struct device *dev = par->info->device;
 906         int buf[64], count, index, i, j, ret;
 907         u32 *values;
 908         u32 val;
 909
 910         count = device_property_count_u32(dev, "init");
 911         if (count < 0)
 912                 return count;
 913         if (count == 0)
 914                 return -EINVAL;
 915
 916         values = kmalloc_array(count + 1, sizeof(*values), GFP_KERNEL);
 917         if (!values)
 918                 return -ENOMEM;
 919
 920         ret = device_property_read_u32_array(dev, "init", values, count);
 921         if (ret)
 922                 goto out_free;
 923
 924         par->fbtftops.reset(par);
 925         if (par->gpio.cs)
 926                 gpiod_set_value(par->gpio.cs, 0);  /* Activate chip */
 927
 928         index = -1;
 929         val = values[++index];
 930
 931         while (index < count) {
 932                 if (val & FBTFT_OF_INIT_CMD) {
 933                         val &= 0xFFFF;
 934                         i = 0;
 935                         while ((index < count) && !(val & 0xFFFF0000)) {
 936                                 if (i > 63) {
 937                                         dev_err(dev,
 938                                                 "%s: Maximum register values exceeded\n",
 939                                                 __func__);
 940                                         ret = -EINVAL;
 941                                         goto out_free;
 942                                 }
 943                                 buf[i++] = val;
 944                                 val = values[++index];
 945                         }
 946                         /* make debug message */
 947                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
 948                                       "init: write_register:\n");
 949                         for (j = 0; j < i; j++)
 950                                 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
 951                                               "buf[%d] = %02X\n", j, buf[j]);
 952
 953                         par->fbtftops.write_register(par, i,
 954                                 buf[0], buf[1], buf[2], buf[3],
 955                                 buf[4], buf[5], buf[6], buf[7],
 956                                 buf[8], buf[9], buf[10], buf[11],
 957                                 buf[12], buf[13], buf[14], buf[15],
 958                                 buf[16], buf[17], buf[18], buf[19],
 959                                 buf[20], buf[21], buf[22], buf[23],
 960                                 buf[24], buf[25], buf[26], buf[27],
 961                                 buf[28], buf[29], buf[30], buf[31],
 962                                 buf[32], buf[33], buf[34], buf[35],
 963                                 buf[36], buf[37], buf[38], buf[39],
 964                                 buf[40], buf[41], buf[42], buf[43],
 965                                 buf[44], buf[45], buf[46], buf[47],
 966                                 buf[48], buf[49], buf[50], buf[51],
 967                                 buf[52], buf[53], buf[54], buf[55],
 968                                 buf[56], buf[57], buf[58], buf[59],
 969                                 buf[60], buf[61], buf[62], buf[63]);
 970                 } else if (val & FBTFT_OF_INIT_DELAY) {
 971                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
 972                                       "init: msleep(%u)\n", val & 0xFFFF);
 973                         msleep(val & 0xFFFF);
 974                         val = values[++index];
 975                 } else {
 976                         dev_err(dev, "illegal init value 0x%X\n", val);
 977                         ret = -EINVAL;
 978                         goto out_free;
 979                 }
 980         }
 981
 982 out_free:
 983         kfree(values);
 984         return ret;
 985 }
 986
 987 /**
 988  * fbtft_init_display() - Generic init_display() function
 989  * @par: Driver data
 990  *
 991  * Uses par->init_sequence to do the initialization
 992  *
 993  * Return: 0 if successful, negative if error
 994  */
 995 int fbtft_init_display(struct fbtft_par *par)
 996 {
 997         int buf[64];
 998         char msg[128];
 999         char str[16];
1000         int i = 0;
1001         int j;
1002
1003         /* sanity check */
1004         if (!par->init_sequence) {
1005                 dev_err(par->info->device,
1006                         "error: init_sequence is not set\n");
1007                 return -EINVAL;
1008         }
1009
1010         /* make sure stop marker exists */
1011         for (i = 0; i < FBTFT_MAX_INIT_SEQUENCE; i++)
1012                 if (par->init_sequence[i] == -3)
1013                         break;
1014         if (i == FBTFT_MAX_INIT_SEQUENCE) {
1015                 dev_err(par->info->device,
1016                         "missing stop marker at end of init sequence\n");
1017                 return -EINVAL;
1018         }
1019
1020         par->fbtftops.reset(par);
1021         if (par->gpio.cs)
1022                 gpiod_set_value(par->gpio.cs, 0);  /* Activate chip */
1023
1024         i = 0;
1025         while (i < FBTFT_MAX_INIT_SEQUENCE) {
1026                 if (par->init_sequence[i] == -3) {
1027                         /* done */
1028                         return 0;
1029                 }
1030                 if (par->init_sequence[i] >= 0) {
1031                         dev_err(par->info->device,
1032                                 "missing delimiter at position %d\n", i);
1033                         return -EINVAL;
1034                 }
1035                 if (par->init_sequence[i + 1] < 0) {
1036                         dev_err(par->info->device,
1037                                 "missing value after delimiter %d at position %d\n",
1038                                 par->init_sequence[i], i);
1039                         return -EINVAL;
1040                 }
1041                 switch (par->init_sequence[i]) {
1042                 case -1:
1043                         i++;
1044                         /* make debug message */
1045                         strcpy(msg, "");
1046                         j = i + 1;
1047                         while (par->init_sequence[j] >= 0) {
1048                                 sprintf(str, "0x%02X ", par->init_sequence[j]);
1049                                 strcat(msg, str);
1050                                 j++;
1051                         }
1052                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1053                                       "init: write(0x%02X) %s\n",
1054                                       par->init_sequence[i], msg);
1055
1056                         /* Write */
1057                         j = 0;
1058                         while (par->init_sequence[i] >= 0) {
1059                                 if (j > 63) {
1060                                         dev_err(par->info->device,
1061                                                 "%s: Maximum register values exceeded\n",
1062                                                 __func__);
1063                                         return -EINVAL;
1064                                 }
1065                                 buf[j++] = par->init_sequence[i++];
1066                         }
1067                         par->fbtftops.write_register(par, j,
1068                                 buf[0], buf[1], buf[2], buf[3],
1069                                 buf[4], buf[5], buf[6], buf[7],
1070                                 buf[8], buf[9], buf[10], buf[11],
1071                                 buf[12], buf[13], buf[14], buf[15],
1072                                 buf[16], buf[17], buf[18], buf[19],
1073                                 buf[20], buf[21], buf[22], buf[23],
1074                                 buf[24], buf[25], buf[26], buf[27],
1075                                 buf[28], buf[29], buf[30], buf[31],
1076                                 buf[32], buf[33], buf[34], buf[35],
1077                                 buf[36], buf[37], buf[38], buf[39],
1078                                 buf[40], buf[41], buf[42], buf[43],
1079                                 buf[44], buf[45], buf[46], buf[47],
1080                                 buf[48], buf[49], buf[50], buf[51],
1081                                 buf[52], buf[53], buf[54], buf[55],
1082                                 buf[56], buf[57], buf[58], buf[59],
1083                                 buf[60], buf[61], buf[62], buf[63]);
1084                         break;
1085                 case -2:
1086                         i++;
1087                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1088                                       "init: mdelay(%d)\n",
1089                                       par->init_sequence[i]);
1090                         mdelay(par->init_sequence[i++]);
1091                         break;
1092                 default:
1093                         dev_err(par->info->device,
1094                                 "unknown delimiter %d at position %d\n",
1095                                 par->init_sequence[i], i);
1096                         return -EINVAL;
1097                 }
1098         }
1099
1100         dev_err(par->info->device,
1101                 "%s: something is wrong. Shouldn't get here.\n", __func__);
1102         return -EINVAL;
1103 }
1104 EXPORT_SYMBOL(fbtft_init_display);
1105
1106 /**
1107  * fbtft_verify_gpios() - Generic verify_gpios() function
1108  * @par: Driver data
1109  *
1110  * Uses @spi, @pdev and @buswidth to determine which GPIOs is needed
1111  *
1112  * Return: 0 if successful, negative if error
1113  */
1114 static int fbtft_verify_gpios(struct fbtft_par *par)
1115 {
1116         struct fbtft_platform_data *pdata = par->pdata;
1117         int i;
1118
1119         fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
1120
1121         if (pdata->display.buswidth != 9 &&  par->startbyte == 0 &&
1122             !par->gpio.dc) {
1123                 dev_err(par->info->device,
1124                         "Missing info about 'dc' gpio. Aborting.\n");
1125                 return -EINVAL;
1126         }
1127
1128         if (!par->pdev)
1129                 return 0;
1130
1131         if (!par->gpio.wr) {
1132                 dev_err(par->info->device, "Missing 'wr' gpio. Aborting.\n");
1133                 return -EINVAL;
1134         }
1135         for (i = 0; i < pdata->display.buswidth; i++) {
1136                 if (!par->gpio.db[i]) {
1137                         dev_err(par->info->device,
1138                                 "Missing 'db%02d' gpio. Aborting.\n", i);
1139                         return -EINVAL;
1140                 }
1141         }
1142
1143         return 0;
1144 }
1145
1146 /* returns 0 if the property is not present */
1147 static u32 fbtft_property_value(struct device *dev, const char *propname)
1148 {
1149         int ret;
1150         u32 val = 0;
1151
1152         ret = device_property_read_u32(dev, propname, &val);
1153         if (ret == 0)
1154                 dev_info(dev, "%s: %s = %u\n", __func__, propname, val);
1155
1156         return val;
1157 }
1158
1159 static struct fbtft_platform_data *fbtft_properties_read(struct device *dev)
1160 {
1161         struct fbtft_platform_data *pdata;
1162
1163         if (!dev_fwnode(dev)) {
1164                 dev_err(dev, "Missing platform data or properties\n");
1165                 return ERR_PTR(-EINVAL);
1166         }
1167
1168         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1169         if (!pdata)
1170                 return ERR_PTR(-ENOMEM);
1171
1172         pdata->display.width = fbtft_property_value(dev, "width");
1173         pdata->display.height = fbtft_property_value(dev, "height");
1174         pdata->display.regwidth = fbtft_property_value(dev, "regwidth");
1175         pdata->display.buswidth = fbtft_property_value(dev, "buswidth");
1176         pdata->display.backlight = fbtft_property_value(dev, "backlight");
1177         pdata->display.bpp = fbtft_property_value(dev, "bpp");
1178         pdata->display.debug = fbtft_property_value(dev, "debug");
1179         pdata->rotate = fbtft_property_value(dev, "rotate");
1180         pdata->bgr = device_property_read_bool(dev, "bgr");
1181         pdata->fps = fbtft_property_value(dev, "fps");
1182         pdata->txbuflen = fbtft_property_value(dev, "txbuflen");
1183         pdata->startbyte = fbtft_property_value(dev, "startbyte");
1184         device_property_read_string(dev, "gamma", (const char **)&pdata->gamma);
1185
1186         if (device_property_present(dev, "led-gpios"))
1187                 pdata->display.backlight = 1;
1188         if (device_property_present(dev, "init"))
1189                 pdata->display.fbtftops.init_display =
1190                         fbtft_init_display_from_property;
1191
1192         pdata->display.fbtftops.request_gpios = fbtft_request_gpios;
1193
1194         return pdata;
1195 }
1196
1197 /**
1198  * fbtft_probe_common() - Generic device probe() helper function
1199  * @display: Display properties
1200  * @sdev: SPI device
1201  * @pdev: Platform device
1202  *
1203  * Allocates, initializes and registers a framebuffer
1204  *
1205  * Either @sdev or @pdev should be NULL
1206  *
1207  * Return: 0 if successful, negative if error
1208  */
1209 int fbtft_probe_common(struct fbtft_display *display,
1210                        struct spi_device *sdev,
1211                        struct platform_device *pdev)
1212 {
1213         struct device *dev;
1214         struct fb_info *info;
1215         struct fbtft_par *par;
1216         struct fbtft_platform_data *pdata;
1217         int ret;
1218
1219         if (sdev)
1220                 dev = &sdev->dev;
1221         else
1222                 dev = &pdev->dev;
1223
1224         if (unlikely(display->debug & DEBUG_DRIVER_INIT_FUNCTIONS))
1225                 dev_info(dev, "%s()\n", __func__);
1226
1227         pdata = dev->platform_data;
1228         if (!pdata) {
1229                 pdata = fbtft_properties_read(dev);
1230                 if (IS_ERR(pdata))
1231                         return PTR_ERR(pdata);
1232         }
1233
1234         info = fbtft_framebuffer_alloc(display, dev, pdata);
1235         if (!info)
1236                 return -ENOMEM;
1237
1238         par = info->par;
1239         par->spi = sdev;
1240         par->pdev = pdev;
1241
1242         if (display->buswidth == 0) {
1243                 dev_err(dev, "buswidth is not set\n");
1244                 return -EINVAL;
1245         }
1246
1247         /* write register functions */
1248         if (display->regwidth == 8 && display->buswidth == 8)
1249                 par->fbtftops.write_register = fbtft_write_reg8_bus8;
1250         else if (display->regwidth == 8 && display->buswidth == 9 && par->spi)
1251                 par->fbtftops.write_register = fbtft_write_reg8_bus9;
1252         else if (display->regwidth == 16 && display->buswidth == 8)
1253                 par->fbtftops.write_register = fbtft_write_reg16_bus8;
1254         else if (display->regwidth == 16 && display->buswidth == 16)
1255                 par->fbtftops.write_register = fbtft_write_reg16_bus16;
1256         else
1257                 dev_warn(dev,
1258                          "no default functions for regwidth=%d and buswidth=%d\n",
1259                          display->regwidth, display->buswidth);
1260
1261         /* write_vmem() functions */
1262         if (display->buswidth == 8)
1263                 par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
1264         else if (display->buswidth == 9)
1265                 par->fbtftops.write_vmem = fbtft_write_vmem16_bus9;
1266         else if (display->buswidth == 16)
1267                 par->fbtftops.write_vmem = fbtft_write_vmem16_bus16;
1268
1269         /* GPIO write() functions */
1270         if (par->pdev) {
1271                 if (display->buswidth == 8)
1272                         par->fbtftops.write = fbtft_write_gpio8_wr;
1273                 else if (display->buswidth == 16)
1274                         par->fbtftops.write = fbtft_write_gpio16_wr;
1275         }
1276
1277         /* 9-bit SPI setup */
1278         if (par->spi && display->buswidth == 9) {
1279                 if (par->spi->master->bits_per_word_mask & SPI_BPW_MASK(9)) {
1280                         par->spi->bits_per_word = 9;
1281                 } else {
1282                         dev_warn(&par->spi->dev,
1283                                  "9-bit SPI not available, emulating using 8-bit.\n");
1284                         /* allocate buffer with room for dc bits */
1285                         par->extra = devm_kzalloc(par->info->device,
1286                                                   par->txbuf.len +
1287                                                   (par->txbuf.len / 8) + 8,
1288                                                   GFP_KERNEL);
1289                         if (!par->extra) {
1290                                 ret = -ENOMEM;
1291                                 goto out_release;
1292                         }
1293                         par->fbtftops.write = fbtft_write_spi_emulate_9;
1294                 }
1295         }
1296
1297         if (!par->fbtftops.verify_gpios)
1298                 par->fbtftops.verify_gpios = fbtft_verify_gpios;
1299
1300         /* make sure we still use the driver provided functions */
1301         fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
1302
1303         /* use init_sequence if provided */
1304         if (par->init_sequence)
1305                 par->fbtftops.init_display = fbtft_init_display;
1306
1307         /* use platform_data provided functions above all */
1308         fbtft_merge_fbtftops(&par->fbtftops, &pdata->display.fbtftops);
1309
1310         ret = fbtft_register_framebuffer(info);
1311         if (ret < 0)
1312                 goto out_release;
1313
1314         return 0;
1315
1316 out_release:
1317         fbtft_framebuffer_release(info);
1318
1319         return ret;
1320 }
1321 EXPORT_SYMBOL(fbtft_probe_common);
1322
1323 /**
1324  * fbtft_remove_common() - Generic device remove() helper function
1325  * @dev: Device
1326  * @info: Framebuffer
1327  *
1328  * Unregisters and releases the framebuffer
1329  *
1330  * Return: 0 if successful, negative if error
1331  */
1332 int fbtft_remove_common(struct device *dev, struct fb_info *info)
1333 {
1334         struct fbtft_par *par;
1335
1336         if (!info)
1337                 return -EINVAL;
1338         par = info->par;
1339         if (par)
1340                 fbtft_par_dbg(DEBUG_DRIVER_INIT_FUNCTIONS, par,
1341                               "%s()\n", __func__);
1342         fbtft_unregister_framebuffer(info);
1343         fbtft_framebuffer_release(info);
1344
1345         return 0;
1346 }
1347 EXPORT_SYMBOL(fbtft_remove_common);
1348
1349 MODULE_LICENSE("GPL");