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