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