drivers/staging/fbtft/fbtft-core.c

   1 /*
   2  * Copyright (C) 2013 Noralf Tronnes
   3  *
   4  * This driver is inspired by:
   5  *   st7735fb.c, Copyright (C) 2011, Matt Porter
   6  *   broadsheetfb.c, Copyright (C) 2008, Jaya Kumar
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/errno.h>
  22 #include <linux/string.h>
  23 #include <linux/mm.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/fb.h>
  28 #include <linux/gpio.h>
  29 #include <linux/spi/spi.h>
  30 #include <linux/delay.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/backlight.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/of.h>
  37 #include <linux/of_gpio.h>
  38 #include <video/mipi_display.h>
  39
  40 #include "fbtft.h"
  41 #include "internal.h"
  42
  43 static unsigned long debug;
  44 module_param(debug, ulong, 0);
  45 MODULE_PARM_DESC(debug, "override device debug level");
  46
  47 #ifdef CONFIG_HAS_DMA
  48 static bool dma = true;
  49 module_param(dma, bool, 0);
  50 MODULE_PARM_DESC(dma, "Use DMA buffer");
  51 #endif
  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 unsigned long fbtft_request_gpios_match(struct fbtft_par *par,
  76                                         const struct fbtft_gpio *gpio)
  77 {
  78         int ret;
  79         long val;
  80
  81         fbtft_par_dbg(DEBUG_REQUEST_GPIOS_MATCH, par, "%s('%s')\n",
  82                 __func__, gpio->name);
  83
  84         if (strcasecmp(gpio->name, "reset") == 0) {
  85                 par->gpio.reset = gpio->gpio;
  86                 return GPIOF_OUT_INIT_HIGH;
  87         } else if (strcasecmp(gpio->name, "dc") == 0) {
  88                 par->gpio.dc = gpio->gpio;
  89                 return GPIOF_OUT_INIT_LOW;
  90         } else if (strcasecmp(gpio->name, "cs") == 0) {
  91                 par->gpio.cs = gpio->gpio;
  92                 return GPIOF_OUT_INIT_HIGH;
  93         } else if (strcasecmp(gpio->name, "wr") == 0) {
  94                 par->gpio.wr = gpio->gpio;
  95                 return GPIOF_OUT_INIT_HIGH;
  96         } else if (strcasecmp(gpio->name, "rd") == 0) {
  97                 par->gpio.rd = gpio->gpio;
  98                 return GPIOF_OUT_INIT_HIGH;
  99         } else if (strcasecmp(gpio->name, "latch") == 0) {
 100                 par->gpio.latch = gpio->gpio;
 101                 return GPIOF_OUT_INIT_LOW;
 102         } else if (gpio->name[0] == 'd' && gpio->name[1] == 'b') {
 103                 ret = kstrtol(&gpio->name[2], 10, &val);
 104                 if (ret == 0 && val < 16) {
 105                         par->gpio.db[val] = gpio->gpio;
 106                         return GPIOF_OUT_INIT_LOW;
 107                 }
 108         } else if (strcasecmp(gpio->name, "led") == 0) {
 109                 par->gpio.led[0] = gpio->gpio;
 110                 return GPIOF_OUT_INIT_LOW;
 111         } else if (strcasecmp(gpio->name, "led_") == 0) {
 112                 par->gpio.led[0] = gpio->gpio;
 113                 return GPIOF_OUT_INIT_HIGH;
 114         }
 115
 116         return FBTFT_GPIO_NO_MATCH;
 117 }
 118
 119 static int fbtft_request_gpios(struct fbtft_par *par)
 120 {
 121         struct fbtft_platform_data *pdata = par->pdata;
 122         const struct fbtft_gpio *gpio;
 123         unsigned long flags;
 124         int ret;
 125
 126         if (!(pdata && pdata->gpios))
 127                 return 0;
 128
 129         gpio = pdata->gpios;
 130         while (gpio->name[0]) {
 131                 flags = FBTFT_GPIO_NO_MATCH;
 132                 /* if driver provides match function, try it first,
 133                  * if no match use our own
 134                  */
 135                 if (par->fbtftops.request_gpios_match)
 136                         flags = par->fbtftops.request_gpios_match(par, gpio);
 137                 if (flags == FBTFT_GPIO_NO_MATCH)
 138                         flags = fbtft_request_gpios_match(par, gpio);
 139                 if (flags != FBTFT_GPIO_NO_MATCH) {
 140                         ret = devm_gpio_request_one(par->info->device,
 141                                         gpio->gpio, flags,
 142                                         par->info->device->driver->name);
 143                         if (ret < 0) {
 144                                 dev_err(par->info->device,
 145                                         "%s: gpio_request_one('%s'=%d) failed with %d\n",
 146                                         __func__, gpio->name,
 147                                         gpio->gpio, ret);
 148                                 return ret;
 149                         }
 150                         fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par,
 151                                 "%s: '%s' = GPIO%d\n",
 152                                 __func__, gpio->name, gpio->gpio);
 153                 }
 154                 gpio++;
 155         }
 156
 157         return 0;
 158 }
 159
 160 #ifdef CONFIG_OF
 161 static int fbtft_request_one_gpio(struct fbtft_par *par,
 162                                   const char *name, int index, int *gpiop)
 163 {
 164         struct device *dev = par->info->device;
 165         struct device_node *node = dev->of_node;
 166         int gpio, flags, ret = 0;
 167         enum of_gpio_flags of_flags;
 168
 169         if (of_find_property(node, name, NULL)) {
 170                 gpio = of_get_named_gpio_flags(node, name, index, &of_flags);
 171                 if (gpio == -ENOENT)
 172                         return 0;
 173                 if (gpio == -EPROBE_DEFER)
 174                         return gpio;
 175                 if (gpio < 0) {
 176                         dev_err(dev,
 177                                 "failed to get '%s' from DT\n", name);
 178                         return gpio;
 179                 }
 180
 181                 /* active low translates to initially low */
 182                 flags = (of_flags & OF_GPIO_ACTIVE_LOW) ? GPIOF_OUT_INIT_LOW :
 183                                                         GPIOF_OUT_INIT_HIGH;
 184                 ret = devm_gpio_request_one(dev, gpio, flags,
 185                                                 dev->driver->name);
 186                 if (ret) {
 187                         dev_err(dev,
 188                                 "gpio_request_one('%s'=%d) failed with %d\n",
 189                                 name, gpio, ret);
 190                         return ret;
 191                 }
 192                 if (gpiop)
 193                         *gpiop = gpio;
 194                 fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' = GPIO%d\n",
 195                                                         __func__, name, gpio);
 196         }
 197
 198         return ret;
 199 }
 200
 201 static int fbtft_request_gpios_dt(struct fbtft_par *par)
 202 {
 203         int i;
 204         int ret;
 205
 206         if (!par->info->device->of_node)
 207                 return -EINVAL;
 208
 209         ret = fbtft_request_one_gpio(par, "reset-gpios", 0, &par->gpio.reset);
 210         if (ret)
 211                 return ret;
 212         ret = fbtft_request_one_gpio(par, "dc-gpios", 0, &par->gpio.dc);
 213         if (ret)
 214                 return ret;
 215         ret = fbtft_request_one_gpio(par, "rd-gpios", 0, &par->gpio.rd);
 216         if (ret)
 217                 return ret;
 218         ret = fbtft_request_one_gpio(par, "wr-gpios", 0, &par->gpio.wr);
 219         if (ret)
 220                 return ret;
 221         ret = fbtft_request_one_gpio(par, "cs-gpios", 0, &par->gpio.cs);
 222         if (ret)
 223                 return ret;
 224         ret = fbtft_request_one_gpio(par, "latch-gpios", 0, &par->gpio.latch);
 225         if (ret)
 226                 return ret;
 227         for (i = 0; i < 16; i++) {
 228                 ret = fbtft_request_one_gpio(par, "db-gpios", i,
 229                                                 &par->gpio.db[i]);
 230                 if (ret)
 231                         return ret;
 232                 ret = fbtft_request_one_gpio(par, "led-gpios", i,
 233                                                 &par->gpio.led[i]);
 234                 if (ret)
 235                         return ret;
 236                 ret = fbtft_request_one_gpio(par, "aux-gpios", i,
 237                                                 &par->gpio.aux[i]);
 238                 if (ret)
 239                         return ret;
 240         }
 241
 242         return 0;
 243 }
 244 #endif
 245
 246 #ifdef CONFIG_FB_BACKLIGHT
 247 static int fbtft_backlight_update_status(struct backlight_device *bd)
 248 {
 249         struct fbtft_par *par = bl_get_data(bd);
 250         bool polarity = !!(bd->props.state & BL_CORE_DRIVER1);
 251
 252         fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 253                 "%s: polarity=%d, power=%d, fb_blank=%d\n",
 254                 __func__, polarity, bd->props.power, bd->props.fb_blank);
 255
 256         if ((bd->props.power == FB_BLANK_UNBLANK) && (bd->props.fb_blank == FB_BLANK_UNBLANK))
 257                 gpio_set_value(par->gpio.led[0], polarity);
 258         else
 259                 gpio_set_value(par->gpio.led[0], !polarity);
 260
 261         return 0;
 262 }
 263
 264 static int fbtft_backlight_get_brightness(struct backlight_device *bd)
 265 {
 266         return bd->props.brightness;
 267 }
 268
 269 void fbtft_unregister_backlight(struct fbtft_par *par)
 270 {
 271         if (par->info->bl_dev) {
 272                 par->info->bl_dev->props.power = FB_BLANK_POWERDOWN;
 273                 backlight_update_status(par->info->bl_dev);
 274                 backlight_device_unregister(par->info->bl_dev);
 275                 par->info->bl_dev = NULL;
 276         }
 277 }
 278
 279 static const struct backlight_ops fbtft_bl_ops = {
 280         .get_brightness = fbtft_backlight_get_brightness,
 281         .update_status  = fbtft_backlight_update_status,
 282 };
 283
 284 void fbtft_register_backlight(struct fbtft_par *par)
 285 {
 286         struct backlight_device *bd;
 287         struct backlight_properties bl_props = { 0, };
 288
 289         if (par->gpio.led[0] == -1) {
 290                 fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 291                         "%s(): led pin not set, exiting.\n", __func__);
 292                 return;
 293         }
 294
 295         bl_props.type = BACKLIGHT_RAW;
 296         /* Assume backlight is off, get polarity from current state of pin */
 297         bl_props.power = FB_BLANK_POWERDOWN;
 298         if (!gpio_get_value(par->gpio.led[0]))
 299                 bl_props.state |= BL_CORE_DRIVER1;
 300
 301         bd = backlight_device_register(dev_driver_string(par->info->device),
 302                                 par->info->device, par, &fbtft_bl_ops, &bl_props);
 303         if (IS_ERR(bd)) {
 304                 dev_err(par->info->device,
 305                         "cannot register backlight device (%ld)\n",
 306                         PTR_ERR(bd));
 307                 return;
 308         }
 309         par->info->bl_dev = bd;
 310
 311         if (!par->fbtftops.unregister_backlight)
 312                 par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
 313 }
 314 #else
 315 void fbtft_register_backlight(struct fbtft_par *par) { };
 316 void fbtft_unregister_backlight(struct fbtft_par *par) { };
 317 #endif
 318 EXPORT_SYMBOL(fbtft_register_backlight);
 319 EXPORT_SYMBOL(fbtft_unregister_backlight);
 320
 321 static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
 322                                int ye)
 323 {
 324         write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
 325                   (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
 326
 327         write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
 328                   (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
 329
 330         write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
 331 }
 332
 333 static void fbtft_reset(struct fbtft_par *par)
 334 {
 335         if (par->gpio.reset == -1)
 336                 return;
 337         fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
 338         gpio_set_value(par->gpio.reset, 0);
 339         udelay(20);
 340         gpio_set_value(par->gpio.reset, 1);
 341         mdelay(120);
 342 }
 343
 344 static void fbtft_update_display(struct fbtft_par *par, unsigned start_line,
 345                                  unsigned end_line)
 346 {
 347         size_t offset, len;
 348         ktime_t ts_start, ts_end;
 349         long fps, throughput;
 350         bool timeit = false;
 351         int ret = 0;
 352
 353         if (unlikely(par->debug & (DEBUG_TIME_FIRST_UPDATE | DEBUG_TIME_EACH_UPDATE))) {
 354                 if ((par->debug & DEBUG_TIME_EACH_UPDATE) ||
 355                                 ((par->debug & DEBUG_TIME_FIRST_UPDATE) && !par->first_update_done)) {
 356                         ts_start = ktime_get();
 357                         timeit = true;
 358                 }
 359         }
 360
 361         /* Sanity checks */
 362         if (start_line > end_line) {
 363                 dev_warn(par->info->device,
 364                         "%s: start_line=%u is larger than end_line=%u. Shouldn't happen, will do full display update\n",
 365                         __func__, start_line, end_line);
 366                 start_line = 0;
 367                 end_line = par->info->var.yres - 1;
 368         }
 369         if (start_line > par->info->var.yres - 1 || end_line > par->info->var.yres - 1) {
 370                 dev_warn(par->info->device,
 371                         "%s: start_line=%u or end_line=%u is larger than max=%d. Shouldn't happen, will do full display update\n",
 372                         __func__, start_line, end_line, par->info->var.yres - 1);
 373                 start_line = 0;
 374                 end_line = par->info->var.yres - 1;
 375         }
 376
 377         fbtft_par_dbg(DEBUG_UPDATE_DISPLAY, par, "%s(start_line=%u, end_line=%u)\n",
 378                 __func__, start_line, end_line);
 379
 380         if (par->fbtftops.set_addr_win)
 381                 par->fbtftops.set_addr_win(par, 0, start_line,
 382                                 par->info->var.xres - 1, end_line);
 383
 384         offset = start_line * par->info->fix.line_length;
 385         len = (end_line - start_line + 1) * par->info->fix.line_length;
 386         ret = par->fbtftops.write_vmem(par, offset, len);
 387         if (ret < 0)
 388                 dev_err(par->info->device,
 389                         "%s: write_vmem failed to update display buffer\n",
 390                         __func__);
 391
 392         if (unlikely(timeit)) {
 393                 ts_end = ktime_get();
 394                 if (ktime_to_ns(par->update_time))
 395                         par->update_time = ts_start;
 396
 397                 par->update_time = ts_start;
 398                 fps = ktime_us_delta(ts_start, par->update_time);
 399                 fps = fps ? 1000000 / fps : 0;
 400
 401                 throughput = ktime_us_delta(ts_end, ts_start);
 402                 throughput = throughput ? (len * 1000) / throughput : 0;
 403                 throughput = throughput * 1000 / 1024;
 404
 405                 dev_info(par->info->device,
 406                         "Display update: %ld kB/s, fps=%ld\n",
 407                         throughput, fps);
 408                 par->first_update_done = true;
 409         }
 410 }
 411
 412 static void fbtft_mkdirty(struct fb_info *info, int y, int height)
 413 {
 414         struct fbtft_par *par = info->par;
 415         struct fb_deferred_io *fbdefio = info->fbdefio;
 416
 417         /* special case, needed ? */
 418         if (y == -1) {
 419                 y = 0;
 420                 height = info->var.yres - 1;
 421         }
 422
 423         /* Mark display lines/area as dirty */
 424         spin_lock(&par->dirty_lock);
 425         if (y < par->dirty_lines_start)
 426                 par->dirty_lines_start = y;
 427         if (y + height - 1 > par->dirty_lines_end)
 428                 par->dirty_lines_end = y + height - 1;
 429         spin_unlock(&par->dirty_lock);
 430
 431         /* Schedule deferred_io to update display (no-op if already on queue)*/
 432         schedule_delayed_work(&info->deferred_work, fbdefio->delay);
 433 }
 434
 435 static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagelist)
 436 {
 437         struct fbtft_par *par = info->par;
 438         unsigned dirty_lines_start, dirty_lines_end;
 439         struct page *page;
 440         unsigned long index;
 441         unsigned y_low = 0, y_high = 0;
 442         int count = 0;
 443
 444         spin_lock(&par->dirty_lock);
 445         dirty_lines_start = par->dirty_lines_start;
 446         dirty_lines_end = par->dirty_lines_end;
 447         /* set display line markers as clean */
 448         par->dirty_lines_start = par->info->var.yres - 1;
 449         par->dirty_lines_end = 0;
 450         spin_unlock(&par->dirty_lock);
 451
 452         /* Mark display lines as dirty */
 453         list_for_each_entry(page, pagelist, lru) {
 454                 count++;
 455                 index = page->index << PAGE_SHIFT;
 456                 y_low = index / info->fix.line_length;
 457                 y_high = (index + PAGE_SIZE - 1) / info->fix.line_length;
 458                 dev_dbg(info->device,
 459                         "page->index=%lu y_low=%d y_high=%d\n",
 460                         page->index, y_low, y_high);
 461                 if (y_high > info->var.yres - 1)
 462                         y_high = info->var.yres - 1;
 463                 if (y_low < dirty_lines_start)
 464                         dirty_lines_start = y_low;
 465                 if (y_high > dirty_lines_end)
 466                         dirty_lines_end = y_high;
 467         }
 468
 469         par->fbtftops.update_display(info->par,
 470                                         dirty_lines_start, dirty_lines_end);
 471 }
 472
 473 static void fbtft_fb_fillrect(struct fb_info *info,
 474                               const struct fb_fillrect *rect)
 475 {
 476         struct fbtft_par *par = info->par;
 477
 478         dev_dbg(info->dev,
 479                 "%s: dx=%d, dy=%d, width=%d, height=%d\n",
 480                 __func__, rect->dx, rect->dy, rect->width, rect->height);
 481         sys_fillrect(info, rect);
 482
 483         par->fbtftops.mkdirty(info, rect->dy, rect->height);
 484 }
 485
 486 static void fbtft_fb_copyarea(struct fb_info *info,
 487                               const struct fb_copyarea *area)
 488 {
 489         struct fbtft_par *par = info->par;
 490
 491         dev_dbg(info->dev,
 492                 "%s: dx=%d, dy=%d, width=%d, height=%d\n",
 493                 __func__,  area->dx, area->dy, area->width, area->height);
 494         sys_copyarea(info, area);
 495
 496         par->fbtftops.mkdirty(info, area->dy, area->height);
 497 }
 498
 499 static void fbtft_fb_imageblit(struct fb_info *info,
 500                                const struct fb_image *image)
 501 {
 502         struct fbtft_par *par = info->par;
 503
 504         dev_dbg(info->dev,
 505                 "%s: dx=%d, dy=%d, width=%d, height=%d\n",
 506                 __func__,  image->dx, image->dy, image->width, image->height);
 507         sys_imageblit(info, image);
 508
 509         par->fbtftops.mkdirty(info, image->dy, image->height);
 510 }
 511
 512 static ssize_t fbtft_fb_write(struct fb_info *info, const char __user *buf,
 513                               size_t count, loff_t *ppos)
 514 {
 515         struct fbtft_par *par = info->par;
 516         ssize_t res;
 517
 518         dev_dbg(info->dev,
 519                 "%s: count=%zd, ppos=%llu\n", __func__,  count, *ppos);
 520         res = fb_sys_write(info, buf, count, ppos);
 521
 522         /* TODO: only mark changed area update all for now */
 523         par->fbtftops.mkdirty(info, -1, 0);
 524
 525         return res;
 526 }
 527
 528 /* from pxafb.c */
 529 static unsigned int chan_to_field(unsigned chan, struct fb_bitfield *bf)
 530 {
 531         chan &= 0xffff;
 532         chan >>= 16 - bf->length;
 533         return chan << bf->offset;
 534 }
 535
 536 static int fbtft_fb_setcolreg(unsigned regno, unsigned red, unsigned green,
 537                               unsigned blue, unsigned transp,
 538                               struct fb_info *info)
 539 {
 540         unsigned val;
 541         int ret = 1;
 542
 543         dev_dbg(info->dev,
 544                 "%s(regno=%u, red=0x%X, green=0x%X, blue=0x%X, trans=0x%X)\n",
 545                 __func__, regno, red, green, blue, transp);
 546
 547         switch (info->fix.visual) {
 548         case FB_VISUAL_TRUECOLOR:
 549                 if (regno < 16) {
 550                         u32 *pal = info->pseudo_palette;
 551
 552                         val  = chan_to_field(red,   &info->var.red);
 553                         val |= chan_to_field(green, &info->var.green);
 554                         val |= chan_to_field(blue,  &info->var.blue);
 555
 556                         pal[regno] = val;
 557                         ret = 0;
 558                 }
 559                 break;
 560
 561         }
 562         return ret;
 563 }
 564
 565 static int fbtft_fb_blank(int blank, struct fb_info *info)
 566 {
 567         struct fbtft_par *par = info->par;
 568         int ret = -EINVAL;
 569
 570         dev_dbg(info->dev, "%s(blank=%d)\n",
 571                 __func__, blank);
 572
 573         if (!par->fbtftops.blank)
 574                 return ret;
 575
 576         switch (blank) {
 577         case FB_BLANK_POWERDOWN:
 578         case FB_BLANK_VSYNC_SUSPEND:
 579         case FB_BLANK_HSYNC_SUSPEND:
 580         case FB_BLANK_NORMAL:
 581                 ret = par->fbtftops.blank(par, true);
 582                 break;
 583         case FB_BLANK_UNBLANK:
 584                 ret = par->fbtftops.blank(par, false);
 585                 break;
 586         }
 587         return ret;
 588 }
 589
 590 static void fbtft_merge_fbtftops(struct fbtft_ops *dst, struct fbtft_ops *src)
 591 {
 592         if (src->write)
 593                 dst->write = src->write;
 594         if (src->read)
 595                 dst->read = src->read;
 596         if (src->write_vmem)
 597                 dst->write_vmem = src->write_vmem;
 598         if (src->write_register)
 599                 dst->write_register = src->write_register;
 600         if (src->set_addr_win)
 601                 dst->set_addr_win = src->set_addr_win;
 602         if (src->reset)
 603                 dst->reset = src->reset;
 604         if (src->mkdirty)
 605                 dst->mkdirty = src->mkdirty;
 606         if (src->update_display)
 607                 dst->update_display = src->update_display;
 608         if (src->init_display)
 609                 dst->init_display = src->init_display;
 610         if (src->blank)
 611                 dst->blank = src->blank;
 612         if (src->request_gpios_match)
 613                 dst->request_gpios_match = src->request_gpios_match;
 614         if (src->request_gpios)
 615                 dst->request_gpios = src->request_gpios;
 616         if (src->verify_gpios)
 617                 dst->verify_gpios = src->verify_gpios;
 618         if (src->register_backlight)
 619                 dst->register_backlight = src->register_backlight;
 620         if (src->unregister_backlight)
 621                 dst->unregister_backlight = src->unregister_backlight;
 622         if (src->set_var)
 623                 dst->set_var = src->set_var;
 624         if (src->set_gamma)
 625                 dst->set_gamma = src->set_gamma;
 626 }
 627
 628 /**
 629  * fbtft_framebuffer_alloc - creates a new frame buffer info structure
 630  *
 631  * @display: pointer to structure describing the display
 632  * @dev: pointer to the device for this fb, this can be NULL
 633  *
 634  * Creates a new frame buffer info structure.
 635  *
 636  * Also creates and populates the following structures:
 637  *   info->fbops
 638  *   info->fbdefio
 639  *   info->pseudo_palette
 640  *   par->fbtftops
 641  *   par->txbuf
 642  *
 643  * Returns the new structure, or NULL if an error occurred.
 644  *
 645  */
 646 struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 647                                         struct device *dev,
 648                                         struct fbtft_platform_data *pdata)
 649 {
 650         struct fb_info *info;
 651         struct fbtft_par *par;
 652         struct fb_ops *fbops = NULL;
 653         struct fb_deferred_io *fbdefio = NULL;
 654         u8 *vmem = NULL;
 655         void *txbuf = NULL;
 656         void *buf = NULL;
 657         unsigned width;
 658         unsigned height;
 659         int txbuflen = display->txbuflen;
 660         unsigned bpp = display->bpp;
 661         unsigned fps = display->fps;
 662         int vmem_size, i;
 663         int *init_sequence = display->init_sequence;
 664         char *gamma = display->gamma;
 665         unsigned long *gamma_curves = NULL;
 666
 667         /* sanity check */
 668         if (display->gamma_num * display->gamma_len > FBTFT_GAMMA_MAX_VALUES_TOTAL) {
 669                 dev_err(dev, "FBTFT_GAMMA_MAX_VALUES_TOTAL=%d is exceeded\n",
 670                         FBTFT_GAMMA_MAX_VALUES_TOTAL);
 671                 return NULL;
 672         }
 673
 674         /* defaults */
 675         if (!fps)
 676                 fps = 20;
 677         if (!bpp)
 678                 bpp = 16;
 679
 680         if (!pdata) {
 681                 dev_err(dev, "platform data is missing\n");
 682                 return NULL;
 683         }
 684
 685         /* override driver values? */
 686         if (pdata->fps)
 687                 fps = pdata->fps;
 688         if (pdata->txbuflen)
 689                 txbuflen = pdata->txbuflen;
 690         if (pdata->display.init_sequence)
 691                 init_sequence = pdata->display.init_sequence;
 692         if (pdata->gamma)
 693                 gamma = pdata->gamma;
 694         if (pdata->display.debug)
 695                 display->debug = pdata->display.debug;
 696         if (pdata->display.backlight)
 697                 display->backlight = pdata->display.backlight;
 698         if (pdata->display.width)
 699                 display->width = pdata->display.width;
 700         if (pdata->display.height)
 701                 display->height = pdata->display.height;
 702         if (pdata->display.buswidth)
 703                 display->buswidth = pdata->display.buswidth;
 704         if (pdata->display.regwidth)
 705                 display->regwidth = pdata->display.regwidth;
 706
 707         display->debug |= debug;
 708         fbtft_expand_debug_value(&display->debug);
 709
 710         switch (pdata->rotate) {
 711         case 90:
 712         case 270:
 713                 width =  display->height;
 714                 height = display->width;
 715                 break;
 716         default:
 717                 width =  display->width;
 718                 height = display->height;
 719         }
 720
 721         vmem_size = display->width * display->height * bpp / 8;
 722         vmem = vzalloc(vmem_size);
 723         if (!vmem)
 724                 goto alloc_fail;
 725
 726         fbops = devm_kzalloc(dev, sizeof(struct fb_ops), GFP_KERNEL);
 727         if (!fbops)
 728                 goto alloc_fail;
 729
 730         fbdefio = devm_kzalloc(dev, sizeof(struct fb_deferred_io), GFP_KERNEL);
 731         if (!fbdefio)
 732                 goto alloc_fail;
 733
 734         buf = devm_kzalloc(dev, 128, GFP_KERNEL);
 735         if (!buf)
 736                 goto alloc_fail;
 737
 738         if (display->gamma_num && display->gamma_len) {
 739                 gamma_curves = devm_kcalloc(dev,
 740                                             display->gamma_num *
 741                                             display->gamma_len,
 742                                             sizeof(gamma_curves[0]),
 743                                             GFP_KERNEL);
 744                 if (!gamma_curves)
 745                         goto alloc_fail;
 746         }
 747
 748         info = framebuffer_alloc(sizeof(struct fbtft_par), dev);
 749         if (!info)
 750                 goto alloc_fail;
 751
 752         info->screen_buffer = vmem;
 753         info->fbops = fbops;
 754         info->fbdefio = fbdefio;
 755
 756         fbops->owner        =      dev->driver->owner;
 757         fbops->fb_read      =      fb_sys_read;
 758         fbops->fb_write     =      fbtft_fb_write;
 759         fbops->fb_fillrect  =      fbtft_fb_fillrect;
 760         fbops->fb_copyarea  =      fbtft_fb_copyarea;
 761         fbops->fb_imageblit =      fbtft_fb_imageblit;
 762         fbops->fb_setcolreg =      fbtft_fb_setcolreg;
 763         fbops->fb_blank     =      fbtft_fb_blank;
 764
 765         fbdefio->delay =           HZ/fps;
 766         fbdefio->deferred_io =     fbtft_deferred_io;
 767         fb_deferred_io_init(info);
 768
 769         strncpy(info->fix.id, dev->driver->name, 16);
 770         info->fix.type =           FB_TYPE_PACKED_PIXELS;
 771         info->fix.visual =         FB_VISUAL_TRUECOLOR;
 772         info->fix.xpanstep =       0;
 773         info->fix.ypanstep =       0;
 774         info->fix.ywrapstep =      0;
 775         info->fix.line_length =    width * bpp / 8;
 776         info->fix.accel =          FB_ACCEL_NONE;
 777         info->fix.smem_len =       vmem_size;
 778
 779         info->var.rotate =         pdata->rotate;
 780         info->var.xres =           width;
 781         info->var.yres =           height;
 782         info->var.xres_virtual =   info->var.xres;
 783         info->var.yres_virtual =   info->var.yres;
 784         info->var.bits_per_pixel = bpp;
 785         info->var.nonstd =         1;
 786
 787         /* RGB565 */
 788         info->var.red.offset =     11;
 789         info->var.red.length =     5;
 790         info->var.green.offset =   5;
 791         info->var.green.length =   6;
 792         info->var.blue.offset =    0;
 793         info->var.blue.length =    5;
 794         info->var.transp.offset =  0;
 795         info->var.transp.length =  0;
 796
 797         info->flags =              FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
 798
 799         par = info->par;
 800         par->info = info;
 801         par->pdata = pdata;
 802         par->debug = display->debug;
 803         par->buf = buf;
 804         spin_lock_init(&par->dirty_lock);
 805         par->bgr = pdata->bgr;
 806         par->startbyte = pdata->startbyte;
 807         par->init_sequence = init_sequence;
 808         par->gamma.curves = gamma_curves;
 809         par->gamma.num_curves = display->gamma_num;
 810         par->gamma.num_values = display->gamma_len;
 811         mutex_init(&par->gamma.lock);
 812         info->pseudo_palette = par->pseudo_palette;
 813
 814         if (par->gamma.curves && gamma) {
 815                 if (fbtft_gamma_parse_str(par,
 816                         par->gamma.curves, gamma, strlen(gamma)))
 817                         goto alloc_fail;
 818         }
 819
 820         /* Transmit buffer */
 821         if (txbuflen == -1)
 822                 txbuflen = vmem_size + 2; /* add in case startbyte is used */
 823
 824 #ifdef __LITTLE_ENDIAN
 825         if ((!txbuflen) && (bpp > 8))
 826                 txbuflen = PAGE_SIZE; /* need buffer for byteswapping */
 827 #endif
 828
 829         if (txbuflen > 0) {
 830 #ifdef CONFIG_HAS_DMA
 831                 if (dma) {
 832                         dev->coherent_dma_mask = ~0;
 833                         txbuf = dmam_alloc_coherent(dev, txbuflen, &par->txbuf.dma, GFP_DMA);
 834                 } else
 835 #endif
 836                 {
 837                         txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
 838                 }
 839                 if (!txbuf)
 840                         goto alloc_fail;
 841                 par->txbuf.buf = txbuf;
 842                 par->txbuf.len = txbuflen;
 843         }
 844
 845         /* Initialize gpios to disabled */
 846         par->gpio.reset = -1;
 847         par->gpio.dc = -1;
 848         par->gpio.rd = -1;
 849         par->gpio.wr = -1;
 850         par->gpio.cs = -1;
 851         par->gpio.latch = -1;
 852         for (i = 0; i < 16; i++) {
 853                 par->gpio.db[i] = -1;
 854                 par->gpio.led[i] = -1;
 855                 par->gpio.aux[i] = -1;
 856         }
 857
 858         /* default fbtft operations */
 859         par->fbtftops.write = fbtft_write_spi;
 860         par->fbtftops.read = fbtft_read_spi;
 861         par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
 862         par->fbtftops.write_register = fbtft_write_reg8_bus8;
 863         par->fbtftops.set_addr_win = fbtft_set_addr_win;
 864         par->fbtftops.reset = fbtft_reset;
 865         par->fbtftops.mkdirty = fbtft_mkdirty;
 866         par->fbtftops.update_display = fbtft_update_display;
 867         par->fbtftops.request_gpios = fbtft_request_gpios;
 868         if (display->backlight)
 869                 par->fbtftops.register_backlight = fbtft_register_backlight;
 870
 871         /* use driver provided functions */
 872         fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
 873
 874         return info;
 875
 876 alloc_fail:
 877         vfree(vmem);
 878
 879         return NULL;
 880 }
 881 EXPORT_SYMBOL(fbtft_framebuffer_alloc);
 882
 883 /**
 884  * fbtft_framebuffer_release - frees up all memory used by the framebuffer
 885  *
 886  * @info: frame buffer info structure
 887  *
 888  */
 889 void fbtft_framebuffer_release(struct fb_info *info)
 890 {
 891         fb_deferred_io_cleanup(info);
 892         vfree(info->screen_buffer);
 893         framebuffer_release(info);
 894 }
 895 EXPORT_SYMBOL(fbtft_framebuffer_release);
 896
 897 /**
 898  *      fbtft_register_framebuffer - registers a tft frame buffer device
 899  *      @fb_info: frame buffer info structure
 900  *
 901  *  Sets SPI driverdata if needed
 902  *  Requests needed gpios.
 903  *  Initializes display
 904  *  Updates display.
 905  *      Registers a frame buffer device @fb_info.
 906  *
 907  *      Returns negative errno on error, or zero for success.
 908  *
 909  */
 910 int fbtft_register_framebuffer(struct fb_info *fb_info)
 911 {
 912         int ret;
 913         char text1[50] = "";
 914         char text2[50] = "";
 915         struct fbtft_par *par = fb_info->par;
 916         struct spi_device *spi = par->spi;
 917
 918         /* sanity checks */
 919         if (!par->fbtftops.init_display) {
 920                 dev_err(fb_info->device, "missing fbtftops.init_display()\n");
 921                 return -EINVAL;
 922         }
 923
 924         if (spi)
 925                 spi_set_drvdata(spi, fb_info);
 926         if (par->pdev)
 927                 platform_set_drvdata(par->pdev, fb_info);
 928
 929         ret = par->fbtftops.request_gpios(par);
 930         if (ret < 0)
 931                 goto reg_fail;
 932
 933         if (par->fbtftops.verify_gpios) {
 934                 ret = par->fbtftops.verify_gpios(par);
 935                 if (ret < 0)
 936                         goto reg_fail;
 937         }
 938
 939         ret = par->fbtftops.init_display(par);
 940         if (ret < 0)
 941                 goto reg_fail;
 942         if (par->fbtftops.set_var) {
 943                 ret = par->fbtftops.set_var(par);
 944                 if (ret < 0)
 945                         goto reg_fail;
 946         }
 947
 948         /* update the entire display */
 949         par->fbtftops.update_display(par, 0, par->info->var.yres - 1);
 950
 951         if (par->fbtftops.set_gamma && par->gamma.curves) {
 952                 ret = par->fbtftops.set_gamma(par, par->gamma.curves);
 953                 if (ret)
 954                         goto reg_fail;
 955         }
 956
 957         if (par->fbtftops.register_backlight)
 958                 par->fbtftops.register_backlight(par);
 959
 960         ret = register_framebuffer(fb_info);
 961         if (ret < 0)
 962                 goto reg_fail;
 963
 964         fbtft_sysfs_init(par);
 965
 966         if (par->txbuf.buf)
 967                 sprintf(text1, ", %zu KiB %sbuffer memory",
 968                         par->txbuf.len >> 10, par->txbuf.dma ? "DMA " : "");
 969         if (spi)
 970                 sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
 971                         spi->chip_select, spi->max_speed_hz / 1000000);
 972         dev_info(fb_info->dev,
 973                 "%s frame buffer, %dx%d, %d KiB video memory%s, fps=%lu%s\n",
 974                 fb_info->fix.id, fb_info->var.xres, fb_info->var.yres,
 975                 fb_info->fix.smem_len >> 10, text1,
 976                 HZ / fb_info->fbdefio->delay, text2);
 977
 978 #ifdef CONFIG_FB_BACKLIGHT
 979         /* Turn on backlight if available */
 980         if (fb_info->bl_dev) {
 981                 fb_info->bl_dev->props.power = FB_BLANK_UNBLANK;
 982                 fb_info->bl_dev->ops->update_status(fb_info->bl_dev);
 983         }
 984 #endif
 985
 986         return 0;
 987
 988 reg_fail:
 989         if (par->fbtftops.unregister_backlight)
 990                 par->fbtftops.unregister_backlight(par);
 991
 992         return ret;
 993 }
 994 EXPORT_SYMBOL(fbtft_register_framebuffer);
 995
 996 /**
 997  *      fbtft_unregister_framebuffer - releases a tft frame buffer device
 998  *      @fb_info: frame buffer info structure
 999  *
1000  *  Frees SPI driverdata if needed
1001  *  Frees gpios.
1002  *      Unregisters frame buffer device.
1003  *
1004  */
1005 int fbtft_unregister_framebuffer(struct fb_info *fb_info)
1006 {
1007         struct fbtft_par *par = fb_info->par;
1008
1009         if (par->fbtftops.unregister_backlight)
1010                 par->fbtftops.unregister_backlight(par);
1011         fbtft_sysfs_exit(par);
1012         return unregister_framebuffer(fb_info);
1013 }
1014 EXPORT_SYMBOL(fbtft_unregister_framebuffer);
1015
1016 #ifdef CONFIG_OF
1017 /**
1018  * fbtft_init_display_dt() - Device Tree init_display() function
1019  * @par: Driver data
1020  *
1021  * Return: 0 if successful, negative if error
1022  */
1023 static int fbtft_init_display_dt(struct fbtft_par *par)
1024 {
1025         struct device_node *node = par->info->device->of_node;
1026         struct property *prop;
1027         const __be32 *p;
1028         u32 val;
1029         int buf[64], i, j;
1030
1031         if (!node)
1032                 return -EINVAL;
1033
1034         prop = of_find_property(node, "init", NULL);
1035         p = of_prop_next_u32(prop, NULL, &val);
1036         if (!p)
1037                 return -EINVAL;
1038
1039         par->fbtftops.reset(par);
1040         if (par->gpio.cs != -1)
1041                 gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
1042
1043         while (p) {
1044                 if (val & FBTFT_OF_INIT_CMD) {
1045                         val &= 0xFFFF;
1046                         i = 0;
1047                         while (p && !(val & 0xFFFF0000)) {
1048                                 if (i > 63) {
1049                                         dev_err(par->info->device,
1050                                         "%s: Maximum register values exceeded\n",
1051                                         __func__);
1052                                         return -EINVAL;
1053                                 }
1054                                 buf[i++] = val;
1055                                 p = of_prop_next_u32(prop, p, &val);
1056                         }
1057                         /* make debug message */
1058                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1059                                 "init: write_register:\n");
1060                         for (j = 0; j < i; j++)
1061                                 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1062                                               "buf[%d] = %02X\n", j, buf[j]);
1063
1064                         par->fbtftops.write_register(par, i,
1065                                 buf[0], buf[1], buf[2], buf[3],
1066                                 buf[4], buf[5], buf[6], buf[7],
1067                                 buf[8], buf[9], buf[10], buf[11],
1068                                 buf[12], buf[13], buf[14], buf[15],
1069                                 buf[16], buf[17], buf[18], buf[19],
1070                                 buf[20], buf[21], buf[22], buf[23],
1071                                 buf[24], buf[25], buf[26], buf[27],
1072                                 buf[28], buf[29], buf[30], buf[31],
1073                                 buf[32], buf[33], buf[34], buf[35],
1074                                 buf[36], buf[37], buf[38], buf[39],
1075                                 buf[40], buf[41], buf[42], buf[43],
1076                                 buf[44], buf[45], buf[46], buf[47],
1077                                 buf[48], buf[49], buf[50], buf[51],
1078                                 buf[52], buf[53], buf[54], buf[55],
1079                                 buf[56], buf[57], buf[58], buf[59],
1080                                 buf[60], buf[61], buf[62], buf[63]);
1081                 } else if (val & FBTFT_OF_INIT_DELAY) {
1082                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1083                                 "init: msleep(%u)\n", val & 0xFFFF);
1084                         msleep(val & 0xFFFF);
1085                         p = of_prop_next_u32(prop, p, &val);
1086                 } else {
1087                         dev_err(par->info->device, "illegal init value 0x%X\n",
1088                                                                         val);
1089                         return -EINVAL;
1090                 }
1091         }
1092
1093         return 0;
1094 }
1095 #endif
1096
1097 /**
1098  * fbtft_init_display() - Generic init_display() function
1099  * @par: Driver data
1100  *
1101  * Uses par->init_sequence to do the initialization
1102  *
1103  * Return: 0 if successful, negative if error
1104  */
1105 int fbtft_init_display(struct fbtft_par *par)
1106 {
1107         int buf[64];
1108         char msg[128];
1109         char str[16];
1110         int i = 0;
1111         int j;
1112
1113         /* sanity check */
1114         if (!par->init_sequence) {
1115                 dev_err(par->info->device,
1116                         "error: init_sequence is not set\n");
1117                 return -EINVAL;
1118         }
1119
1120         /* make sure stop marker exists */
1121         for (i = 0; i < FBTFT_MAX_INIT_SEQUENCE; i++)
1122                 if (par->init_sequence[i] == -3)
1123                         break;
1124         if (i == FBTFT_MAX_INIT_SEQUENCE) {
1125                 dev_err(par->info->device,
1126                         "missing stop marker at end of init sequence\n");
1127                 return -EINVAL;
1128         }
1129
1130         par->fbtftops.reset(par);
1131         if (par->gpio.cs != -1)
1132                 gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
1133
1134         i = 0;
1135         while (i < FBTFT_MAX_INIT_SEQUENCE) {
1136                 if (par->init_sequence[i] == -3) {
1137                         /* done */
1138                         return 0;
1139                 }
1140                 if (par->init_sequence[i] >= 0) {
1141                         dev_err(par->info->device,
1142                                 "missing delimiter at position %d\n", i);
1143                         return -EINVAL;
1144                 }
1145                 if (par->init_sequence[i + 1] < 0) {
1146                         dev_err(par->info->device,
1147                                 "missing value after delimiter %d at position %d\n",
1148                                 par->init_sequence[i], i);
1149                         return -EINVAL;
1150                 }
1151                 switch (par->init_sequence[i]) {
1152                 case -1:
1153                         i++;
1154                         /* make debug message */
1155                         strcpy(msg, "");
1156                         j = i + 1;
1157                         while (par->init_sequence[j] >= 0) {
1158                                 sprintf(str, "0x%02X ", par->init_sequence[j]);
1159                                 strcat(msg, str);
1160                                 j++;
1161                         }
1162                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1163                                 "init: write(0x%02X) %s\n",
1164                                 par->init_sequence[i], msg);
1165
1166                         /* Write */
1167                         j = 0;
1168                         while (par->init_sequence[i] >= 0) {
1169                                 if (j > 63) {
1170                                         dev_err(par->info->device,
1171                                         "%s: Maximum register values exceeded\n",
1172                                         __func__);
1173                                         return -EINVAL;
1174                                 }
1175                                 buf[j++] = par->init_sequence[i++];
1176                         }
1177                         par->fbtftops.write_register(par, j,
1178                                 buf[0], buf[1], buf[2], buf[3],
1179                                 buf[4], buf[5], buf[6], buf[7],
1180                                 buf[8], buf[9], buf[10], buf[11],
1181                                 buf[12], buf[13], buf[14], buf[15],
1182                                 buf[16], buf[17], buf[18], buf[19],
1183                                 buf[20], buf[21], buf[22], buf[23],
1184                                 buf[24], buf[25], buf[26], buf[27],
1185                                 buf[28], buf[29], buf[30], buf[31],
1186                                 buf[32], buf[33], buf[34], buf[35],
1187                                 buf[36], buf[37], buf[38], buf[39],
1188                                 buf[40], buf[41], buf[42], buf[43],
1189                                 buf[44], buf[45], buf[46], buf[47],
1190                                 buf[48], buf[49], buf[50], buf[51],
1191                                 buf[52], buf[53], buf[54], buf[55],
1192                                 buf[56], buf[57], buf[58], buf[59],
1193                                 buf[60], buf[61], buf[62], buf[63]);
1194                         break;
1195                 case -2:
1196                         i++;
1197                         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1198                                 "init: mdelay(%d)\n", par->init_sequence[i]);
1199                         mdelay(par->init_sequence[i++]);
1200                         break;
1201                 default:
1202                         dev_err(par->info->device,
1203                                 "unknown delimiter %d at position %d\n",
1204                                 par->init_sequence[i], i);
1205                         return -EINVAL;
1206                 }
1207         }
1208
1209         dev_err(par->info->device,
1210                 "%s: something is wrong. Shouldn't get here.\n", __func__);
1211         return -EINVAL;
1212 }
1213 EXPORT_SYMBOL(fbtft_init_display);
1214
1215 /**
1216  * fbtft_verify_gpios() - Generic verify_gpios() function
1217  * @par: Driver data
1218  *
1219  * Uses @spi, @pdev and @buswidth to determine which GPIOs is needed
1220  *
1221  * Return: 0 if successful, negative if error
1222  */
1223 static int fbtft_verify_gpios(struct fbtft_par *par)
1224 {
1225         struct fbtft_platform_data *pdata = par->pdata;
1226         int i;
1227
1228         fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
1229
1230         if (pdata->display.buswidth != 9 && par->startbyte == 0 &&
1231                                                         par->gpio.dc < 0) {
1232                 dev_err(par->info->device,
1233                         "Missing info about 'dc' gpio. Aborting.\n");
1234                 return -EINVAL;
1235         }
1236
1237         if (!par->pdev)
1238                 return 0;
1239
1240         if (par->gpio.wr < 0) {
1241                 dev_err(par->info->device, "Missing 'wr' gpio. Aborting.\n");
1242                 return -EINVAL;
1243         }
1244         for (i = 0; i < pdata->display.buswidth; i++) {
1245                 if (par->gpio.db[i] < 0) {
1246                         dev_err(par->info->device,
1247                                 "Missing 'db%02d' gpio. Aborting.\n", i);
1248                         return -EINVAL;
1249                 }
1250         }
1251
1252         return 0;
1253 }
1254
1255 #ifdef CONFIG_OF
1256 /* returns 0 if the property is not present */
1257 static u32 fbtft_of_value(struct device_node *node, const char *propname)
1258 {
1259         int ret;
1260         u32 val = 0;
1261
1262         ret = of_property_read_u32(node, propname, &val);
1263         if (ret == 0)
1264                 pr_info("%s: %s = %u\n", __func__, propname, val);
1265
1266         return val;
1267 }
1268
1269 static struct fbtft_platform_data *fbtft_probe_dt(struct device *dev)
1270 {
1271         struct device_node *node = dev->of_node;
1272         struct fbtft_platform_data *pdata;
1273
1274         if (!node) {
1275                 dev_err(dev, "Missing platform data or DT\n");
1276                 return ERR_PTR(-EINVAL);
1277         }
1278
1279         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1280         if (!pdata)
1281                 return ERR_PTR(-ENOMEM);
1282
1283         pdata->display.width = fbtft_of_value(node, "width");
1284         pdata->display.height = fbtft_of_value(node, "height");
1285         pdata->display.regwidth = fbtft_of_value(node, "regwidth");
1286         pdata->display.buswidth = fbtft_of_value(node, "buswidth");
1287         pdata->display.backlight = fbtft_of_value(node, "backlight");
1288         pdata->display.bpp = fbtft_of_value(node, "bpp");
1289         pdata->display.debug = fbtft_of_value(node, "debug");
1290         pdata->rotate = fbtft_of_value(node, "rotate");
1291         pdata->bgr = of_property_read_bool(node, "bgr");
1292         pdata->fps = fbtft_of_value(node, "fps");
1293         pdata->txbuflen = fbtft_of_value(node, "txbuflen");
1294         pdata->startbyte = fbtft_of_value(node, "startbyte");
1295         of_property_read_string(node, "gamma", (const char **)&pdata->gamma);
1296
1297         if (of_find_property(node, "led-gpios", NULL))
1298                 pdata->display.backlight = 1;
1299         if (of_find_property(node, "init", NULL))
1300                 pdata->display.fbtftops.init_display = fbtft_init_display_dt;
1301         pdata->display.fbtftops.request_gpios = fbtft_request_gpios_dt;
1302
1303         return pdata;
1304 }
1305 #else
1306 static struct fbtft_platform_data *fbtft_probe_dt(struct device *dev)
1307 {
1308         dev_err(dev, "Missing platform data\n");
1309         return ERR_PTR(-EINVAL);
1310 }
1311 #endif
1312
1313 /**
1314  * fbtft_probe_common() - Generic device probe() helper function
1315  * @display: Display properties
1316  * @sdev: SPI device
1317  * @pdev: Platform device
1318  *
1319  * Allocates, initializes and registers a framebuffer
1320  *
1321  * Either @sdev or @pdev should be NULL
1322  *
1323  * Return: 0 if successful, negative if error
1324  */
1325 int fbtft_probe_common(struct fbtft_display *display,
1326                         struct spi_device *sdev, struct platform_device *pdev)
1327 {
1328         struct device *dev;
1329         struct fb_info *info;
1330         struct fbtft_par *par;
1331         struct fbtft_platform_data *pdata;
1332         int ret;
1333
1334         if (sdev)
1335                 dev = &sdev->dev;
1336         else
1337                 dev = &pdev->dev;
1338
1339         if (unlikely(display->debug & DEBUG_DRIVER_INIT_FUNCTIONS))
1340                 dev_info(dev, "%s()\n", __func__);
1341
1342         pdata = dev->platform_data;
1343         if (!pdata) {
1344                 pdata = fbtft_probe_dt(dev);
1345                 if (IS_ERR(pdata))
1346                         return PTR_ERR(pdata);
1347         }
1348
1349         info = fbtft_framebuffer_alloc(display, dev, pdata);
1350         if (!info)
1351                 return -ENOMEM;
1352
1353         par = info->par;
1354         par->spi = sdev;
1355         par->pdev = pdev;
1356
1357         if (display->buswidth == 0) {
1358                 dev_err(dev, "buswidth is not set\n");
1359                 return -EINVAL;
1360         }
1361
1362         /* write register functions */
1363         if (display->regwidth == 8 && display->buswidth == 8) {
1364                 par->fbtftops.write_register = fbtft_write_reg8_bus8;
1365         } else
1366         if (display->regwidth == 8 && display->buswidth == 9 && par->spi) {
1367                 par->fbtftops.write_register = fbtft_write_reg8_bus9;
1368         } else if (display->regwidth == 16 && display->buswidth == 8) {
1369                 par->fbtftops.write_register = fbtft_write_reg16_bus8;
1370         } else if (display->regwidth == 16 && display->buswidth == 16) {
1371                 par->fbtftops.write_register = fbtft_write_reg16_bus16;
1372         } else {
1373                 dev_warn(dev,
1374                         "no default functions for regwidth=%d and buswidth=%d\n",
1375                         display->regwidth, display->buswidth);
1376         }
1377
1378         /* write_vmem() functions */
1379         if (display->buswidth == 8)
1380                 par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
1381         else if (display->buswidth == 9)
1382                 par->fbtftops.write_vmem = fbtft_write_vmem16_bus9;
1383         else if (display->buswidth == 16)
1384                 par->fbtftops.write_vmem = fbtft_write_vmem16_bus16;
1385
1386         /* GPIO write() functions */
1387         if (par->pdev) {
1388                 if (display->buswidth == 8)
1389                         par->fbtftops.write = fbtft_write_gpio8_wr;
1390                 else if (display->buswidth == 16)
1391                         par->fbtftops.write = fbtft_write_gpio16_wr;
1392         }
1393
1394         /* 9-bit SPI setup */
1395         if (par->spi && display->buswidth == 9) {
1396                 if (par->spi->master->bits_per_word_mask & SPI_BPW_MASK(9)) {
1397                         par->spi->bits_per_word = 9;
1398                 } else {
1399                         dev_warn(&par->spi->dev,
1400                                 "9-bit SPI not available, emulating using 8-bit.\n");
1401                         /* allocate buffer with room for dc bits */
1402                         par->extra = devm_kzalloc(par->info->device,
1403                                 par->txbuf.len + (par->txbuf.len / 8) + 8,
1404                                 GFP_KERNEL);
1405                         if (!par->extra) {
1406                                 ret = -ENOMEM;
1407                                 goto out_release;
1408                         }
1409                         par->fbtftops.write = fbtft_write_spi_emulate_9;
1410                 }
1411         }
1412
1413         if (!par->fbtftops.verify_gpios)
1414                 par->fbtftops.verify_gpios = fbtft_verify_gpios;
1415
1416         /* make sure we still use the driver provided functions */
1417         fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
1418
1419         /* use init_sequence if provided */
1420         if (par->init_sequence)
1421                 par->fbtftops.init_display = fbtft_init_display;
1422
1423         /* use platform_data provided functions above all */
1424         fbtft_merge_fbtftops(&par->fbtftops, &pdata->display.fbtftops);
1425
1426         ret = fbtft_register_framebuffer(info);
1427         if (ret < 0)
1428                 goto out_release;
1429
1430         return 0;
1431
1432 out_release:
1433         fbtft_framebuffer_release(info);
1434
1435         return ret;
1436 }
1437 EXPORT_SYMBOL(fbtft_probe_common);
1438
1439 /**
1440  * fbtft_remove_common() - Generic device remove() helper function
1441  * @dev: Device
1442  * @info: Framebuffer
1443  *
1444  * Unregisters and releases the framebuffer
1445  *
1446  * Return: 0 if successful, negative if error
1447  */
1448 int fbtft_remove_common(struct device *dev, struct fb_info *info)
1449 {
1450         struct fbtft_par *par;
1451
1452         if (!info)
1453                 return -EINVAL;
1454         par = info->par;
1455         if (par)
1456                 fbtft_par_dbg(DEBUG_DRIVER_INIT_FUNCTIONS, par,
1457                         "%s()\n", __func__);
1458         fbtft_unregister_framebuffer(info);
1459         fbtft_framebuffer_release(info);
1460
1461         return 0;
1462 }
1463 EXPORT_SYMBOL(fbtft_remove_common);
1464
1465 MODULE_LICENSE("GPL");