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.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/spinlock.h>
26 #include <linux/of.h>
27 #include <linux/of_gpio.h>
28 #include <video/mipi_display.h>
29 
30 #include "fbtft.h"
31 #include "internal.h"
32 
33 static unsigned long debug;
34 module_param(debug, ulong, 0000);
35 MODULE_PARM_DESC(debug, "override device debug level");
36 
37 int fbtft_write_buf_dc(struct fbtft_par *par, void *buf, size_t len, int dc)
38 {
39 	int ret;
40 
41 	if (gpio_is_valid(par->gpio.dc))
42 		gpio_set_value(par->gpio.dc, dc);
43 
44 	ret = par->fbtftops.write(par, buf, len);
45 	if (ret < 0)
46 		dev_err(par->info->device,
47 			"write() failed and returned %d\n", ret);
48 	return ret;
49 }
50 EXPORT_SYMBOL(fbtft_write_buf_dc);
51 
52 void fbtft_dbg_hex(const struct device *dev, int groupsize,
53 		   void *buf, size_t len, const char *fmt, ...)
54 {
55 	va_list args;
56 	static char textbuf[512];
57 	char *text = textbuf;
58 	size_t text_len;
59 
60 	va_start(args, fmt);
61 	text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
62 	va_end(args);
63 
64 	hex_dump_to_buffer(buf, len, 32, groupsize, text + text_len,
65 			   512 - text_len, false);
66 
67 	if (len > 32)
68 		dev_info(dev, "%s ...\n", text);
69 	else
70 		dev_info(dev, "%s\n", text);
71 }
72 EXPORT_SYMBOL(fbtft_dbg_hex);
73 
74 static unsigned long fbtft_request_gpios_match(struct fbtft_par *par,
75 					       const struct fbtft_gpio *gpio)
76 {
77 	int ret;
78 	unsigned int val;
79 
80 	fbtft_par_dbg(DEBUG_REQUEST_GPIOS_MATCH, par, "%s('%s')\n",
81 		      __func__, gpio->name);
82 
83 	if (strcasecmp(gpio->name, "reset") == 0) {
84 		par->gpio.reset = gpio->gpio;
85 		return GPIOF_OUT_INIT_HIGH;
86 	} else if (strcasecmp(gpio->name, "dc") == 0) {
87 		par->gpio.dc = gpio->gpio;
88 		return GPIOF_OUT_INIT_LOW;
89 	} else if (strcasecmp(gpio->name, "cs") == 0) {
90 		par->gpio.cs = gpio->gpio;
91 		return GPIOF_OUT_INIT_HIGH;
92 	} else if (strcasecmp(gpio->name, "wr") == 0) {
93 		par->gpio.wr = gpio->gpio;
94 		return GPIOF_OUT_INIT_HIGH;
95 	} else if (strcasecmp(gpio->name, "rd") == 0) {
96 		par->gpio.rd = gpio->gpio;
97 		return GPIOF_OUT_INIT_HIGH;
98 	} else if (strcasecmp(gpio->name, "latch") == 0) {
99 		par->gpio.latch = gpio->gpio;
100 		return GPIOF_OUT_INIT_LOW;
101 	} else if (gpio->name[0] == 'd' && gpio->name[1] == 'b') {
102 		ret = kstrtouint(&gpio->name[2], 10, &val);
103 		if (ret == 0 && val < 16) {
104 			par->gpio.db[val] = gpio->gpio;
105 			return GPIOF_OUT_INIT_LOW;
106 		}
107 	} else if (strcasecmp(gpio->name, "led") == 0) {
108 		par->gpio.led[0] = gpio->gpio;
109 		return GPIOF_OUT_INIT_LOW;
110 	} else if (strcasecmp(gpio->name, "led_") == 0) {
111 		par->gpio.led[0] = gpio->gpio;
112 		return GPIOF_OUT_INIT_HIGH;
113 	}
114 
115 	return FBTFT_GPIO_NO_MATCH;
116 }
117 
118 static int fbtft_request_gpios(struct fbtft_par *par)
119 {
120 	struct fbtft_platform_data *pdata = par->pdata;
121 	const struct fbtft_gpio *gpio;
122 	unsigned long flags;
123 	int ret;
124 
125 	if (!(pdata && pdata->gpios))
126 		return 0;
127 
128 	gpio = pdata->gpios;
129 	while (gpio->name[0]) {
130 		flags = FBTFT_GPIO_NO_MATCH;
131 		/* if driver provides match function, try it first,
132 		 * if no match use our own
133 		 */
134 		if (par->fbtftops.request_gpios_match)
135 			flags = par->fbtftops.request_gpios_match(par, gpio);
136 		if (flags == FBTFT_GPIO_NO_MATCH)
137 			flags = fbtft_request_gpios_match(par, gpio);
138 		if (flags != FBTFT_GPIO_NO_MATCH) {
139 			ret = devm_gpio_request_one(par->info->device,
140 					      gpio->gpio, flags,
141 					      par->info->device->driver->name);
142 			if (ret < 0) {
143 				dev_err(par->info->device,
144 					"%s: gpio_request_one('%s'=%d) failed with %d\n",
145 					__func__, gpio->name,
146 					gpio->gpio, ret);
147 				return ret;
148 			}
149 			fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par,
150 				      "%s: '%s' = GPIO%d\n",
151 				      __func__, gpio->name, gpio->gpio);
152 		}
153 		gpio++;
154 	}
155 
156 	return 0;
157 }
158 
159 #ifdef CONFIG_OF
160 static int fbtft_request_one_gpio(struct fbtft_par *par,
161 				  const char *name, int index, int *gpiop)
162 {
163 	struct device *dev = par->info->device;
164 	struct device_node *node = dev->of_node;
165 	int gpio, flags, ret = 0;
166 	enum of_gpio_flags of_flags;
167 
168 	if (of_find_property(node, name, NULL)) {
169 		gpio = of_get_named_gpio_flags(node, name, index, &of_flags);
170 		if (gpio == -ENOENT)
171 			return 0;
172 		if (gpio == -EPROBE_DEFER)
173 			return gpio;
174 		if (gpio < 0) {
175 			dev_err(dev,
176 				"failed to get '%s' from DT\n", name);
177 			return gpio;
178 		}
179 
180 		/* active low translates to initially low */
181 		flags = (of_flags & OF_GPIO_ACTIVE_LOW) ? GPIOF_OUT_INIT_LOW :
182 							GPIOF_OUT_INIT_HIGH;
183 		ret = devm_gpio_request_one(dev, gpio, flags,
184 					    dev->driver->name);
185 		if (ret) {
186 			dev_err(dev,
187 				"gpio_request_one('%s'=%d) failed with %d\n",
188 				name, gpio, ret);
189 			return ret;
190 		}
191 		if (gpiop)
192 			*gpiop = gpio;
193 		fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' = GPIO%d\n",
194 			      __func__, name, gpio);
195 	}
196 
197 	return ret;
198 }
199 
200 static int fbtft_request_gpios_dt(struct fbtft_par *par)
201 {
202 	int i;
203 	int ret;
204 
205 	if (!par->info->device->of_node)
206 		return -EINVAL;
207 
208 	ret = fbtft_request_one_gpio(par, "reset-gpios", 0, &par->gpio.reset);
209 	if (ret)
210 		return ret;
211 	ret = fbtft_request_one_gpio(par, "dc-gpios", 0, &par->gpio.dc);
212 	if (ret)
213 		return ret;
214 	ret = fbtft_request_one_gpio(par, "rd-gpios", 0, &par->gpio.rd);
215 	if (ret)
216 		return ret;
217 	ret = fbtft_request_one_gpio(par, "wr-gpios", 0, &par->gpio.wr);
218 	if (ret)
219 		return ret;
220 	ret = fbtft_request_one_gpio(par, "cs-gpios", 0, &par->gpio.cs);
221 	if (ret)
222 		return ret;
223 	ret = fbtft_request_one_gpio(par, "latch-gpios", 0, &par->gpio.latch);
224 	if (ret)
225 		return ret;
226 	for (i = 0; i < 16; i++) {
227 		ret = fbtft_request_one_gpio(par, "db-gpios", i,
228 					     &par->gpio.db[i]);
229 		if (ret)
230 			return ret;
231 		ret = fbtft_request_one_gpio(par, "led-gpios", i,
232 					     &par->gpio.led[i]);
233 		if (ret)
234 			return ret;
235 		ret = fbtft_request_one_gpio(par, "aux-gpios", i,
236 					     &par->gpio.aux[i]);
237 		if (ret)
238 			return ret;
239 	}
240 
241 	return 0;
242 }
243 #endif
244 
245 #ifdef CONFIG_FB_BACKLIGHT
246 static int fbtft_backlight_update_status(struct backlight_device *bd)
247 {
248 	struct fbtft_par *par = bl_get_data(bd);
249 	bool polarity = par->polarity;
250 
251 	fbtft_par_dbg(DEBUG_BACKLIGHT, par,
252 		      "%s: polarity=%d, power=%d, fb_blank=%d\n",
253 		      __func__, polarity, bd->props.power, bd->props.fb_blank);
254 
255 	if ((bd->props.power == FB_BLANK_UNBLANK) &&
256 	    (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 		par->polarity = true;
300 
301 	bd = backlight_device_register(dev_driver_string(par->info->device),
302 				       par->info->device, par,
303 				       &fbtft_bl_ops, &bl_props);
304 	if (IS_ERR(bd)) {
305 		dev_err(par->info->device,
306 			"cannot register backlight device (%ld)\n",
307 			PTR_ERR(bd));
308 		return;
309 	}
310 	par->info->bl_dev = bd;
311 
312 	if (!par->fbtftops.unregister_backlight)
313 		par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
314 }
315 #else
316 void fbtft_register_backlight(struct fbtft_par *par) { };
317 void fbtft_unregister_backlight(struct fbtft_par *par) { };
318 #endif
319 EXPORT_SYMBOL(fbtft_register_backlight);
320 EXPORT_SYMBOL(fbtft_unregister_backlight);
321 
322 static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
323 			       int ye)
324 {
325 	write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
326 		  (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
327 
328 	write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
329 		  (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
330 
331 	write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
332 }
333 
334 static void fbtft_reset(struct fbtft_par *par)
335 {
336 	if (par->gpio.reset == -1)
337 		return;
338 	fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
339 	gpio_set_value_cansleep(par->gpio.reset, 0);
340 	usleep_range(20, 40);
341 	gpio_set_value_cansleep(par->gpio.reset, 1);
342 	msleep(120);
343 }
344 
345 static void fbtft_update_display(struct fbtft_par *par, unsigned int start_line,
346 				 unsigned int end_line)
347 {
348 	size_t offset, len;
349 	ktime_t ts_start, ts_end;
350 	long fps, throughput;
351 	bool timeit = false;
352 	int ret = 0;
353 
354 	if (unlikely(par->debug & (DEBUG_TIME_FIRST_UPDATE |
355 			DEBUG_TIME_EACH_UPDATE))) {
356 		if ((par->debug & DEBUG_TIME_EACH_UPDATE) ||
357 		    ((par->debug & DEBUG_TIME_FIRST_UPDATE) &&
358 		    !par->first_update_done)) {
359 			ts_start = ktime_get();
360 			timeit = true;
361 		}
362 	}
363 
364 	/* Sanity checks */
365 	if (start_line > end_line) {
366 		dev_warn(par->info->device,
367 			 "%s: start_line=%u is larger than end_line=%u. Shouldn't happen, will do full display update\n",
368 			 __func__, start_line, end_line);
369 		start_line = 0;
370 		end_line = par->info->var.yres - 1;
371 	}
372 	if (start_line > par->info->var.yres - 1 ||
373 	    end_line > par->info->var.yres - 1) {
374 		dev_warn(par->info->device,
375 			 "%s: start_line=%u or end_line=%u is larger than max=%d. Shouldn't happen, will do full display update\n",
376 			 __func__, start_line,
377 			 end_line, par->info->var.yres - 1);
378 		start_line = 0;
379 		end_line = par->info->var.yres - 1;
380 	}
381 
382 	fbtft_par_dbg(DEBUG_UPDATE_DISPLAY, par, "%s(start_line=%u, end_line=%u)\n",
383 		      __func__, start_line, end_line);
384 
385 	if (par->fbtftops.set_addr_win)
386 		par->fbtftops.set_addr_win(par, 0, start_line,
387 				par->info->var.xres - 1, end_line);
388 
389 	offset = start_line * par->info->fix.line_length;
390 	len = (end_line - start_line + 1) * par->info->fix.line_length;
391 	ret = par->fbtftops.write_vmem(par, offset, len);
392 	if (ret < 0)
393 		dev_err(par->info->device,
394 			"%s: write_vmem failed to update display buffer\n",
395 			__func__);
396 
397 	if (unlikely(timeit)) {
398 		ts_end = ktime_get();
399 		if (!ktime_to_ns(par->update_time))
400 			par->update_time = ts_start;
401 
402 		fps = ktime_us_delta(ts_start, par->update_time);
403 		par->update_time = ts_start;
404 		fps = fps ? 1000000 / fps : 0;
405 
406 		throughput = ktime_us_delta(ts_end, ts_start);
407 		throughput = throughput ? (len * 1000) / throughput : 0;
408 		throughput = throughput * 1000 / 1024;
409 
410 		dev_info(par->info->device,
411 			 "Display update: %ld kB/s, fps=%ld\n",
412 			 throughput, fps);
413 		par->first_update_done = true;
414 	}
415 }
416 
417 static void fbtft_mkdirty(struct fb_info *info, int y, int height)
418 {
419 	struct fbtft_par *par = info->par;
420 	struct fb_deferred_io *fbdefio = info->fbdefio;
421 
422 	/* special case, needed ? */
423 	if (y == -1) {
424 		y = 0;
425 		height = info->var.yres - 1;
426 	}
427 
428 	/* Mark display lines/area as dirty */
429 	spin_lock(&par->dirty_lock);
430 	if (y < par->dirty_lines_start)
431 		par->dirty_lines_start = y;
432 	if (y + height - 1 > par->dirty_lines_end)
433 		par->dirty_lines_end = y + height - 1;
434 	spin_unlock(&par->dirty_lock);
435 
436 	/* Schedule deferred_io to update display (no-op if already on queue)*/
437 	schedule_delayed_work(&info->deferred_work, fbdefio->delay);
438 }
439 
440 static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagelist)
441 {
442 	struct fbtft_par *par = info->par;
443 	unsigned int dirty_lines_start, dirty_lines_end;
444 	struct page *page;
445 	unsigned long index;
446 	unsigned int y_low = 0, y_high = 0;
447 	int count = 0;
448 
449 	spin_lock(&par->dirty_lock);
450 	dirty_lines_start = par->dirty_lines_start;
451 	dirty_lines_end = par->dirty_lines_end;
452 	/* set display line markers as clean */
453 	par->dirty_lines_start = par->info->var.yres - 1;
454 	par->dirty_lines_end = 0;
455 	spin_unlock(&par->dirty_lock);
456 
457 	/* Mark display lines as dirty */
458 	list_for_each_entry(page, pagelist, lru) {
459 		count++;
460 		index = page->index << PAGE_SHIFT;
461 		y_low = index / info->fix.line_length;
462 		y_high = (index + PAGE_SIZE - 1) / info->fix.line_length;
463 		dev_dbg(info->device,
464 			"page->index=%lu y_low=%d y_high=%d\n",
465 			page->index, y_low, y_high);
466 		if (y_high > info->var.yres - 1)
467 			y_high = info->var.yres - 1;
468 		if (y_low < dirty_lines_start)
469 			dirty_lines_start = y_low;
470 		if (y_high > dirty_lines_end)
471 			dirty_lines_end = y_high;
472 	}
473 
474 	par->fbtftops.update_display(info->par,
475 					dirty_lines_start, dirty_lines_end);
476 }
477 
478 static void fbtft_fb_fillrect(struct fb_info *info,
479 			      const struct fb_fillrect *rect)
480 {
481 	struct fbtft_par *par = info->par;
482 
483 	dev_dbg(info->dev,
484 		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
485 		__func__, rect->dx, rect->dy, rect->width, rect->height);
486 	sys_fillrect(info, rect);
487 
488 	par->fbtftops.mkdirty(info, rect->dy, rect->height);
489 }
490 
491 static void fbtft_fb_copyarea(struct fb_info *info,
492 			      const struct fb_copyarea *area)
493 {
494 	struct fbtft_par *par = info->par;
495 
496 	dev_dbg(info->dev,
497 		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
498 		__func__,  area->dx, area->dy, area->width, area->height);
499 	sys_copyarea(info, area);
500 
501 	par->fbtftops.mkdirty(info, area->dy, area->height);
502 }
503 
504 static void fbtft_fb_imageblit(struct fb_info *info,
505 			       const struct fb_image *image)
506 {
507 	struct fbtft_par *par = info->par;
508 
509 	dev_dbg(info->dev,
510 		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
511 		__func__,  image->dx, image->dy, image->width, image->height);
512 	sys_imageblit(info, image);
513 
514 	par->fbtftops.mkdirty(info, image->dy, image->height);
515 }
516 
517 static ssize_t fbtft_fb_write(struct fb_info *info, const char __user *buf,
518 			      size_t count, loff_t *ppos)
519 {
520 	struct fbtft_par *par = info->par;
521 	ssize_t res;
522 
523 	dev_dbg(info->dev,
524 		"%s: count=%zd, ppos=%llu\n", __func__,  count, *ppos);
525 	res = fb_sys_write(info, buf, count, ppos);
526 
527 	/* TODO: only mark changed area update all for now */
528 	par->fbtftops.mkdirty(info, -1, 0);
529 
530 	return res;
531 }
532 
533 /* from pxafb.c */
534 static unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf)
535 {
536 	chan &= 0xffff;
537 	chan >>= 16 - bf->length;
538 	return chan << bf->offset;
539 }
540 
541 static int fbtft_fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
542 			      unsigned int blue, unsigned int transp,
543 			      struct fb_info *info)
544 {
545 	unsigned int val;
546 	int ret = 1;
547 
548 	dev_dbg(info->dev,
549 		"%s(regno=%u, red=0x%X, green=0x%X, blue=0x%X, trans=0x%X)\n",
550 		__func__, regno, red, green, blue, transp);
551 
552 	switch (info->fix.visual) {
553 	case FB_VISUAL_TRUECOLOR:
554 		if (regno < 16) {
555 			u32 *pal = info->pseudo_palette;
556 
557 			val  = chan_to_field(red,   &info->var.red);
558 			val |= chan_to_field(green, &info->var.green);
559 			val |= chan_to_field(blue,  &info->var.blue);
560 
561 			pal[regno] = val;
562 			ret = 0;
563 		}
564 		break;
565 	}
566 	return ret;
567 }
568 
569 static int fbtft_fb_blank(int blank, struct fb_info *info)
570 {
571 	struct fbtft_par *par = info->par;
572 	int ret = -EINVAL;
573 
574 	dev_dbg(info->dev, "%s(blank=%d)\n",
575 		__func__, blank);
576 
577 	if (!par->fbtftops.blank)
578 		return ret;
579 
580 	switch (blank) {
581 	case FB_BLANK_POWERDOWN:
582 	case FB_BLANK_VSYNC_SUSPEND:
583 	case FB_BLANK_HSYNC_SUSPEND:
584 	case FB_BLANK_NORMAL:
585 		ret = par->fbtftops.blank(par, true);
586 		break;
587 	case FB_BLANK_UNBLANK:
588 		ret = par->fbtftops.blank(par, false);
589 		break;
590 	}
591 	return ret;
592 }
593 
594 static void fbtft_merge_fbtftops(struct fbtft_ops *dst, struct fbtft_ops *src)
595 {
596 	if (src->write)
597 		dst->write = src->write;
598 	if (src->read)
599 		dst->read = src->read;
600 	if (src->write_vmem)
601 		dst->write_vmem = src->write_vmem;
602 	if (src->write_register)
603 		dst->write_register = src->write_register;
604 	if (src->set_addr_win)
605 		dst->set_addr_win = src->set_addr_win;
606 	if (src->reset)
607 		dst->reset = src->reset;
608 	if (src->mkdirty)
609 		dst->mkdirty = src->mkdirty;
610 	if (src->update_display)
611 		dst->update_display = src->update_display;
612 	if (src->init_display)
613 		dst->init_display = src->init_display;
614 	if (src->blank)
615 		dst->blank = src->blank;
616 	if (src->request_gpios_match)
617 		dst->request_gpios_match = src->request_gpios_match;
618 	if (src->request_gpios)
619 		dst->request_gpios = src->request_gpios;
620 	if (src->verify_gpios)
621 		dst->verify_gpios = src->verify_gpios;
622 	if (src->register_backlight)
623 		dst->register_backlight = src->register_backlight;
624 	if (src->unregister_backlight)
625 		dst->unregister_backlight = src->unregister_backlight;
626 	if (src->set_var)
627 		dst->set_var = src->set_var;
628 	if (src->set_gamma)
629 		dst->set_gamma = src->set_gamma;
630 }
631 
632 /**
633  * fbtft_framebuffer_alloc - creates a new frame buffer info structure
634  *
635  * @display: pointer to structure describing the display
636  * @dev: pointer to the device for this fb, this can be NULL
637  *
638  * Creates a new frame buffer info structure.
639  *
640  * Also creates and populates the following structures:
641  *   info->fbops
642  *   info->fbdefio
643  *   info->pseudo_palette
644  *   par->fbtftops
645  *   par->txbuf
646  *
647  * Returns the new structure, or NULL if an error occurred.
648  *
649  */
650 struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
651 					struct device *dev,
652 					struct fbtft_platform_data *pdata)
653 {
654 	struct fb_info *info;
655 	struct fbtft_par *par;
656 	struct fb_ops *fbops = NULL;
657 	struct fb_deferred_io *fbdefio = NULL;
658 	u8 *vmem = NULL;
659 	void *txbuf = NULL;
660 	void *buf = NULL;
661 	unsigned int width;
662 	unsigned int height;
663 	int txbuflen = display->txbuflen;
664 	unsigned int bpp = display->bpp;
665 	unsigned int fps = display->fps;
666 	int vmem_size, i;
667 	const s16 *init_sequence = display->init_sequence;
668 	char *gamma = display->gamma;
669 	u32 *gamma_curves = NULL;
670 
671 	/* sanity check */
672 	if (display->gamma_num * display->gamma_len >
673 			FBTFT_GAMMA_MAX_VALUES_TOTAL) {
674 		dev_err(dev, "FBTFT_GAMMA_MAX_VALUES_TOTAL=%d is exceeded\n",
675 			FBTFT_GAMMA_MAX_VALUES_TOTAL);
676 		return NULL;
677 	}
678 
679 	/* defaults */
680 	if (!fps)
681 		fps = 20;
682 	if (!bpp)
683 		bpp = 16;
684 
685 	if (!pdata) {
686 		dev_err(dev, "platform data is missing\n");
687 		return NULL;
688 	}
689 
690 	/* override driver values? */
691 	if (pdata->fps)
692 		fps = pdata->fps;
693 	if (pdata->txbuflen)
694 		txbuflen = pdata->txbuflen;
695 	if (pdata->display.init_sequence)
696 		init_sequence = pdata->display.init_sequence;
697 	if (pdata->gamma)
698 		gamma = pdata->gamma;
699 	if (pdata->display.debug)
700 		display->debug = pdata->display.debug;
701 	if (pdata->display.backlight)
702 		display->backlight = pdata->display.backlight;
703 	if (pdata->display.width)
704 		display->width = pdata->display.width;
705 	if (pdata->display.height)
706 		display->height = pdata->display.height;
707 	if (pdata->display.buswidth)
708 		display->buswidth = pdata->display.buswidth;
709 	if (pdata->display.regwidth)
710 		display->regwidth = pdata->display.regwidth;
711 
712 	display->debug |= debug;
713 	fbtft_expand_debug_value(&display->debug);
714 
715 	switch (pdata->rotate) {
716 	case 90:
717 	case 270:
718 		width =  display->height;
719 		height = display->width;
720 		break;
721 	default:
722 		width =  display->width;
723 		height = display->height;
724 	}
725 
726 	vmem_size = display->width * display->height * bpp / 8;
727 	vmem = vzalloc(vmem_size);
728 	if (!vmem)
729 		goto alloc_fail;
730 
731 	fbops = devm_kzalloc(dev, sizeof(struct fb_ops), GFP_KERNEL);
732 	if (!fbops)
733 		goto alloc_fail;
734 
735 	fbdefio = devm_kzalloc(dev, sizeof(struct fb_deferred_io), GFP_KERNEL);
736 	if (!fbdefio)
737 		goto alloc_fail;
738 
739 	buf = devm_kzalloc(dev, 128, GFP_KERNEL);
740 	if (!buf)
741 		goto alloc_fail;
742 
743 	if (display->gamma_num && display->gamma_len) {
744 		gamma_curves = devm_kcalloc(dev,
745 					    display->gamma_num *
746 					    display->gamma_len,
747 					    sizeof(gamma_curves[0]),
748 					    GFP_KERNEL);
749 		if (!gamma_curves)
750 			goto alloc_fail;
751 	}
752 
753 	info = framebuffer_alloc(sizeof(struct fbtft_par), dev);
754 	if (!info)
755 		goto alloc_fail;
756 
757 	info->screen_buffer = vmem;
758 	info->fbops = fbops;
759 	info->fbdefio = fbdefio;
760 
761 	fbops->owner        =      dev->driver->owner;
762 	fbops->fb_read      =      fb_sys_read;
763 	fbops->fb_write     =      fbtft_fb_write;
764 	fbops->fb_fillrect  =      fbtft_fb_fillrect;
765 	fbops->fb_copyarea  =      fbtft_fb_copyarea;
766 	fbops->fb_imageblit =      fbtft_fb_imageblit;
767 	fbops->fb_setcolreg =      fbtft_fb_setcolreg;
768 	fbops->fb_blank     =      fbtft_fb_blank;
769 
770 	fbdefio->delay =           HZ / fps;
771 	fbdefio->deferred_io =     fbtft_deferred_io;
772 	fb_deferred_io_init(info);
773 
774 	strncpy(info->fix.id, dev->driver->name, 16);
775 	info->fix.type =           FB_TYPE_PACKED_PIXELS;
776 	info->fix.visual =         FB_VISUAL_TRUECOLOR;
777 	info->fix.xpanstep =	   0;
778 	info->fix.ypanstep =	   0;
779 	info->fix.ywrapstep =	   0;
780 	info->fix.line_length =    width * bpp / 8;
781 	info->fix.accel =          FB_ACCEL_NONE;
782 	info->fix.smem_len =       vmem_size;
783 
784 	info->var.rotate =         pdata->rotate;
785 	info->var.xres =           width;
786 	info->var.yres =           height;
787 	info->var.xres_virtual =   info->var.xres;
788 	info->var.yres_virtual =   info->var.yres;
789 	info->var.bits_per_pixel = bpp;
790 	info->var.nonstd =         1;
791 
792 	/* RGB565 */
793 	info->var.red.offset =     11;
794 	info->var.red.length =     5;
795 	info->var.green.offset =   5;
796 	info->var.green.length =   6;
797 	info->var.blue.offset =    0;
798 	info->var.blue.length =    5;
799 	info->var.transp.offset =  0;
800 	info->var.transp.length =  0;
801 
802 	info->flags =              FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
803 
804 	par = info->par;
805 	par->info = info;
806 	par->pdata = pdata;
807 	par->debug = display->debug;
808 	par->buf = buf;
809 	spin_lock_init(&par->dirty_lock);
810 	par->bgr = pdata->bgr;
811 	par->startbyte = pdata->startbyte;
812 	par->init_sequence = init_sequence;
813 	par->gamma.curves = gamma_curves;
814 	par->gamma.num_curves = display->gamma_num;
815 	par->gamma.num_values = display->gamma_len;
816 	mutex_init(&par->gamma.lock);
817 	info->pseudo_palette = par->pseudo_palette;
818 
819 	if (par->gamma.curves && gamma) {
820 		if (fbtft_gamma_parse_str(par, par->gamma.curves, gamma,
821 					  strlen(gamma)))
822 			goto alloc_fail;
823 	}
824 
825 	/* Transmit buffer */
826 	if (txbuflen == -1)
827 		txbuflen = vmem_size + 2; /* add in case startbyte is used */
828 	if (txbuflen >= vmem_size + 2)
829 		txbuflen = 0;
830 
831 #ifdef __LITTLE_ENDIAN
832 	if ((!txbuflen) && (bpp > 8))
833 		txbuflen = PAGE_SIZE; /* need buffer for byteswapping */
834 #endif
835 
836 	if (txbuflen > 0) {
837 		txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
838 		if (!txbuf)
839 			goto alloc_fail;
840 		par->txbuf.buf = txbuf;
841 		par->txbuf.len = txbuflen;
842 	}
843 
844 	/* Initialize gpios to disabled */
845 	par->gpio.reset = -1;
846 	par->gpio.dc = -1;
847 	par->gpio.rd = -1;
848 	par->gpio.wr = -1;
849 	par->gpio.cs = -1;
850 	par->gpio.latch = -1;
851 	for (i = 0; i < 16; i++) {
852 		par->gpio.db[i] = -1;
853 		par->gpio.led[i] = -1;
854 		par->gpio.aux[i] = -1;
855 	}
856 
857 	/* default fbtft operations */
858 	par->fbtftops.write = fbtft_write_spi;
859 	par->fbtftops.read = fbtft_read_spi;
860 	par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
861 	par->fbtftops.write_register = fbtft_write_reg8_bus8;
862 	par->fbtftops.set_addr_win = fbtft_set_addr_win;
863 	par->fbtftops.reset = fbtft_reset;
864 	par->fbtftops.mkdirty = fbtft_mkdirty;
865 	par->fbtftops.update_display = fbtft_update_display;
866 	par->fbtftops.request_gpios = fbtft_request_gpios;
867 	if (display->backlight)
868 		par->fbtftops.register_backlight = fbtft_register_backlight;
869 
870 	/* use driver provided functions */
871 	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
872 
873 	return info;
874 
875 alloc_fail:
876 	vfree(vmem);
877 
878 	return NULL;
879 }
880 EXPORT_SYMBOL(fbtft_framebuffer_alloc);
881 
882 /**
883  * fbtft_framebuffer_release - frees up all memory used by the framebuffer
884  *
885  * @info: frame buffer info structure
886  *
887  */
888 void fbtft_framebuffer_release(struct fb_info *info)
889 {
890 	fb_deferred_io_cleanup(info);
891 	vfree(info->screen_buffer);
892 	framebuffer_release(info);
893 }
894 EXPORT_SYMBOL(fbtft_framebuffer_release);
895 
896 /**
897  *	fbtft_register_framebuffer - registers a tft frame buffer device
898  *	@fb_info: frame buffer info structure
899  *
900  *  Sets SPI driverdata if needed
901  *  Requests needed gpios.
902  *  Initializes display
903  *  Updates display.
904  *	Registers a frame buffer device @fb_info.
905  *
906  *	Returns negative errno on error, or zero for success.
907  *
908  */
909 int fbtft_register_framebuffer(struct fb_info *fb_info)
910 {
911 	int ret;
912 	char text1[50] = "";
913 	char text2[50] = "";
914 	struct fbtft_par *par = fb_info->par;
915 	struct spi_device *spi = par->spi;
916 
917 	/* sanity checks */
918 	if (!par->fbtftops.init_display) {
919 		dev_err(fb_info->device, "missing fbtftops.init_display()\n");
920 		return -EINVAL;
921 	}
922 
923 	if (spi)
924 		spi_set_drvdata(spi, fb_info);
925 	if (par->pdev)
926 		platform_set_drvdata(par->pdev, fb_info);
927 
928 	ret = par->fbtftops.request_gpios(par);
929 	if (ret < 0)
930 		goto reg_fail;
931 
932 	if (par->fbtftops.verify_gpios) {
933 		ret = par->fbtftops.verify_gpios(par);
934 		if (ret < 0)
935 			goto reg_fail;
936 	}
937 
938 	ret = par->fbtftops.init_display(par);
939 	if (ret < 0)
940 		goto reg_fail;
941 	if (par->fbtftops.set_var) {
942 		ret = par->fbtftops.set_var(par);
943 		if (ret < 0)
944 			goto reg_fail;
945 	}
946 
947 	/* update the entire display */
948 	par->fbtftops.update_display(par, 0, par->info->var.yres - 1);
949 
950 	if (par->fbtftops.set_gamma && par->gamma.curves) {
951 		ret = par->fbtftops.set_gamma(par, par->gamma.curves);
952 		if (ret)
953 			goto reg_fail;
954 	}
955 
956 	if (par->fbtftops.register_backlight)
957 		par->fbtftops.register_backlight(par);
958 
959 	ret = register_framebuffer(fb_info);
960 	if (ret < 0)
961 		goto reg_fail;
962 
963 	fbtft_sysfs_init(par);
964 
965 	if (par->txbuf.buf && par->txbuf.len >= 1024)
966 		sprintf(text1, ", %zu KiB buffer memory", par->txbuf.len >> 10);
967 	if (spi)
968 		sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
969 			spi->chip_select, spi->max_speed_hz / 1000000);
970 	dev_info(fb_info->dev,
971 		 "%s frame buffer, %dx%d, %d KiB video memory%s, fps=%lu%s\n",
972 		 fb_info->fix.id, fb_info->var.xres, fb_info->var.yres,
973 		 fb_info->fix.smem_len >> 10, text1,
974 		 HZ / fb_info->fbdefio->delay, text2);
975 
976 #ifdef CONFIG_FB_BACKLIGHT
977 	/* Turn on backlight if available */
978 	if (fb_info->bl_dev) {
979 		fb_info->bl_dev->props.power = FB_BLANK_UNBLANK;
980 		fb_info->bl_dev->ops->update_status(fb_info->bl_dev);
981 	}
982 #endif
983 
984 	return 0;
985 
986 reg_fail:
987 	if (par->fbtftops.unregister_backlight)
988 		par->fbtftops.unregister_backlight(par);
989 
990 	return ret;
991 }
992 EXPORT_SYMBOL(fbtft_register_framebuffer);
993 
994 /**
995  *	fbtft_unregister_framebuffer - releases a tft frame buffer device
996  *	@fb_info: frame buffer info structure
997  *
998  *  Frees SPI driverdata if needed
999  *  Frees gpios.
1000  *	Unregisters frame buffer device.
1001  *
1002  */
1003 int fbtft_unregister_framebuffer(struct fb_info *fb_info)
1004 {
1005 	struct fbtft_par *par = fb_info->par;
1006 
1007 	if (par->fbtftops.unregister_backlight)
1008 		par->fbtftops.unregister_backlight(par);
1009 	fbtft_sysfs_exit(par);
1010 	return unregister_framebuffer(fb_info);
1011 }
1012 EXPORT_SYMBOL(fbtft_unregister_framebuffer);
1013 
1014 #ifdef CONFIG_OF
1015 /**
1016  * fbtft_init_display_dt() - Device Tree init_display() function
1017  * @par: Driver data
1018  *
1019  * Return: 0 if successful, negative if error
1020  */
1021 static int fbtft_init_display_dt(struct fbtft_par *par)
1022 {
1023 	struct device_node *node = par->info->device->of_node;
1024 	struct property *prop;
1025 	const __be32 *p;
1026 	u32 val;
1027 	int buf[64], i, j;
1028 
1029 	if (!node)
1030 		return -EINVAL;
1031 
1032 	prop = of_find_property(node, "init", NULL);
1033 	p = of_prop_next_u32(prop, NULL, &val);
1034 	if (!p)
1035 		return -EINVAL;
1036 
1037 	par->fbtftops.reset(par);
1038 	if (par->gpio.cs != -1)
1039 		gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
1040 
1041 	while (p) {
1042 		if (val & FBTFT_OF_INIT_CMD) {
1043 			val &= 0xFFFF;
1044 			i = 0;
1045 			while (p && !(val & 0xFFFF0000)) {
1046 				if (i > 63) {
1047 					dev_err(par->info->device,
1048 						"%s: Maximum register values exceeded\n",
1049 						__func__);
1050 					return -EINVAL;
1051 				}
1052 				buf[i++] = val;
1053 				p = of_prop_next_u32(prop, p, &val);
1054 			}
1055 			/* make debug message */
1056 			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1057 				      "init: write_register:\n");
1058 			for (j = 0; j < i; j++)
1059 				fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1060 					      "buf[%d] = %02X\n", j, buf[j]);
1061 
1062 			par->fbtftops.write_register(par, i,
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 		} else if (val & FBTFT_OF_INIT_DELAY) {
1080 			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1081 				      "init: msleep(%u)\n", val & 0xFFFF);
1082 			msleep(val & 0xFFFF);
1083 			p = of_prop_next_u32(prop, p, &val);
1084 		} else {
1085 			dev_err(par->info->device, "illegal init value 0x%X\n",
1086 				val);
1087 			return -EINVAL;
1088 		}
1089 	}
1090 
1091 	return 0;
1092 }
1093 #endif
1094 
1095 /**
1096  * fbtft_init_display() - Generic init_display() function
1097  * @par: Driver data
1098  *
1099  * Uses par->init_sequence to do the initialization
1100  *
1101  * Return: 0 if successful, negative if error
1102  */
1103 int fbtft_init_display(struct fbtft_par *par)
1104 {
1105 	int buf[64];
1106 	char msg[128];
1107 	char str[16];
1108 	int i = 0;
1109 	int j;
1110 
1111 	/* sanity check */
1112 	if (!par->init_sequence) {
1113 		dev_err(par->info->device,
1114 			"error: init_sequence is not set\n");
1115 		return -EINVAL;
1116 	}
1117 
1118 	/* make sure stop marker exists */
1119 	for (i = 0; i < FBTFT_MAX_INIT_SEQUENCE; i++)
1120 		if (par->init_sequence[i] == -3)
1121 			break;
1122 	if (i == FBTFT_MAX_INIT_SEQUENCE) {
1123 		dev_err(par->info->device,
1124 			"missing stop marker at end of init sequence\n");
1125 		return -EINVAL;
1126 	}
1127 
1128 	par->fbtftops.reset(par);
1129 	if (par->gpio.cs != -1)
1130 		gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
1131 
1132 	i = 0;
1133 	while (i < FBTFT_MAX_INIT_SEQUENCE) {
1134 		if (par->init_sequence[i] == -3) {
1135 			/* done */
1136 			return 0;
1137 		}
1138 		if (par->init_sequence[i] >= 0) {
1139 			dev_err(par->info->device,
1140 				"missing delimiter at position %d\n", i);
1141 			return -EINVAL;
1142 		}
1143 		if (par->init_sequence[i + 1] < 0) {
1144 			dev_err(par->info->device,
1145 				"missing value after delimiter %d at position %d\n",
1146 				par->init_sequence[i], i);
1147 			return -EINVAL;
1148 		}
1149 		switch (par->init_sequence[i]) {
1150 		case -1:
1151 			i++;
1152 			/* make debug message */
1153 			strcpy(msg, "");
1154 			j = i + 1;
1155 			while (par->init_sequence[j] >= 0) {
1156 				sprintf(str, "0x%02X ", par->init_sequence[j]);
1157 				strcat(msg, str);
1158 				j++;
1159 			}
1160 			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1161 				      "init: write(0x%02X) %s\n",
1162 				      par->init_sequence[i], msg);
1163 
1164 			/* Write */
1165 			j = 0;
1166 			while (par->init_sequence[i] >= 0) {
1167 				if (j > 63) {
1168 					dev_err(par->info->device,
1169 						"%s: Maximum register values exceeded\n",
1170 						__func__);
1171 					return -EINVAL;
1172 				}
1173 				buf[j++] = par->init_sequence[i++];
1174 			}
1175 			par->fbtftops.write_register(par, j,
1176 				buf[0], buf[1], buf[2], buf[3],
1177 				buf[4], buf[5], buf[6], buf[7],
1178 				buf[8], buf[9], buf[10], buf[11],
1179 				buf[12], buf[13], buf[14], buf[15],
1180 				buf[16], buf[17], buf[18], buf[19],
1181 				buf[20], buf[21], buf[22], buf[23],
1182 				buf[24], buf[25], buf[26], buf[27],
1183 				buf[28], buf[29], buf[30], buf[31],
1184 				buf[32], buf[33], buf[34], buf[35],
1185 				buf[36], buf[37], buf[38], buf[39],
1186 				buf[40], buf[41], buf[42], buf[43],
1187 				buf[44], buf[45], buf[46], buf[47],
1188 				buf[48], buf[49], buf[50], buf[51],
1189 				buf[52], buf[53], buf[54], buf[55],
1190 				buf[56], buf[57], buf[58], buf[59],
1191 				buf[60], buf[61], buf[62], buf[63]);
1192 			break;
1193 		case -2:
1194 			i++;
1195 			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
1196 				      "init: mdelay(%d)\n",
1197 				      par->init_sequence[i]);
1198 			mdelay(par->init_sequence[i++]);
1199 			break;
1200 		default:
1201 			dev_err(par->info->device,
1202 				"unknown delimiter %d at position %d\n",
1203 				par->init_sequence[i], i);
1204 			return -EINVAL;
1205 		}
1206 	}
1207 
1208 	dev_err(par->info->device,
1209 		"%s: something is wrong. Shouldn't get here.\n", __func__);
1210 	return -EINVAL;
1211 }
1212 EXPORT_SYMBOL(fbtft_init_display);
1213 
1214 /**
1215  * fbtft_verify_gpios() - Generic verify_gpios() function
1216  * @par: Driver data
1217  *
1218  * Uses @spi, @pdev and @buswidth to determine which GPIOs is needed
1219  *
1220  * Return: 0 if successful, negative if error
1221  */
1222 static int fbtft_verify_gpios(struct fbtft_par *par)
1223 {
1224 	struct fbtft_platform_data *pdata = par->pdata;
1225 	int i;
1226 
1227 	fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
1228 
1229 	if (pdata->display.buswidth != 9 &&  par->startbyte == 0 &&
1230 	    par->gpio.dc < 0) {
1231 		dev_err(par->info->device,
1232 			"Missing info about 'dc' gpio. Aborting.\n");
1233 		return -EINVAL;
1234 	}
1235 
1236 	if (!par->pdev)
1237 		return 0;
1238 
1239 	if (par->gpio.wr < 0) {
1240 		dev_err(par->info->device, "Missing 'wr' gpio. Aborting.\n");
1241 		return -EINVAL;
1242 	}
1243 	for (i = 0; i < pdata->display.buswidth; i++) {
1244 		if (par->gpio.db[i] < 0) {
1245 			dev_err(par->info->device,
1246 				"Missing 'db%02d' gpio. Aborting.\n", i);
1247 			return -EINVAL;
1248 		}
1249 	}
1250 
1251 	return 0;
1252 }
1253 
1254 #ifdef CONFIG_OF
1255 /* returns 0 if the property is not present */
1256 static u32 fbtft_of_value(struct device_node *node, const char *propname)
1257 {
1258 	int ret;
1259 	u32 val = 0;
1260 
1261 	ret = of_property_read_u32(node, propname, &val);
1262 	if (ret == 0)
1263 		pr_info("%s: %s = %u\n", __func__, propname, val);
1264 
1265 	return val;
1266 }
1267 
1268 static struct fbtft_platform_data *fbtft_probe_dt(struct device *dev)
1269 {
1270 	struct device_node *node = dev->of_node;
1271 	struct fbtft_platform_data *pdata;
1272 
1273 	if (!node) {
1274 		dev_err(dev, "Missing platform data or DT\n");
1275 		return ERR_PTR(-EINVAL);
1276 	}
1277 
1278 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1279 	if (!pdata)
1280 		return ERR_PTR(-ENOMEM);
1281 
1282 	pdata->display.width = fbtft_of_value(node, "width");
1283 	pdata->display.height = fbtft_of_value(node, "height");
1284 	pdata->display.regwidth = fbtft_of_value(node, "regwidth");
1285 	pdata->display.buswidth = fbtft_of_value(node, "buswidth");
1286 	pdata->display.backlight = fbtft_of_value(node, "backlight");
1287 	pdata->display.bpp = fbtft_of_value(node, "bpp");
1288 	pdata->display.debug = fbtft_of_value(node, "debug");
1289 	pdata->rotate = fbtft_of_value(node, "rotate");
1290 	pdata->bgr = of_property_read_bool(node, "bgr");
1291 	pdata->fps = fbtft_of_value(node, "fps");
1292 	pdata->txbuflen = fbtft_of_value(node, "txbuflen");
1293 	pdata->startbyte = fbtft_of_value(node, "startbyte");
1294 	of_property_read_string(node, "gamma", (const char **)&pdata->gamma);
1295 
1296 	if (of_find_property(node, "led-gpios", NULL))
1297 		pdata->display.backlight = 1;
1298 	if (of_find_property(node, "init", NULL))
1299 		pdata->display.fbtftops.init_display = fbtft_init_display_dt;
1300 	pdata->display.fbtftops.request_gpios = fbtft_request_gpios_dt;
1301 
1302 	return pdata;
1303 }
1304 #else
1305 static struct fbtft_platform_data *fbtft_probe_dt(struct device *dev)
1306 {
1307 	dev_err(dev, "Missing platform data\n");
1308 	return ERR_PTR(-EINVAL);
1309 }
1310 #endif
1311 
1312 /**
1313  * fbtft_probe_common() - Generic device probe() helper function
1314  * @display: Display properties
1315  * @sdev: SPI device
1316  * @pdev: Platform device
1317  *
1318  * Allocates, initializes and registers a framebuffer
1319  *
1320  * Either @sdev or @pdev should be NULL
1321  *
1322  * Return: 0 if successful, negative if error
1323  */
1324 int fbtft_probe_common(struct fbtft_display *display,
1325 		       struct spi_device *sdev,
1326 		       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 if (display->regwidth == 8 && display->buswidth == 9 && par->spi)
1366 		par->fbtftops.write_register = fbtft_write_reg8_bus9;
1367 	else if (display->regwidth == 16 && display->buswidth == 8)
1368 		par->fbtftops.write_register = fbtft_write_reg16_bus8;
1369 	else if (display->regwidth == 16 && display->buswidth == 16)
1370 		par->fbtftops.write_register = fbtft_write_reg16_bus16;
1371 	else
1372 		dev_warn(dev,
1373 			 "no default functions for regwidth=%d and buswidth=%d\n",
1374 			 display->regwidth, display->buswidth);
1375 
1376 	/* write_vmem() functions */
1377 	if (display->buswidth == 8)
1378 		par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
1379 	else if (display->buswidth == 9)
1380 		par->fbtftops.write_vmem = fbtft_write_vmem16_bus9;
1381 	else if (display->buswidth == 16)
1382 		par->fbtftops.write_vmem = fbtft_write_vmem16_bus16;
1383 
1384 	/* GPIO write() functions */
1385 	if (par->pdev) {
1386 		if (display->buswidth == 8)
1387 			par->fbtftops.write = fbtft_write_gpio8_wr;
1388 		else if (display->buswidth == 16)
1389 			par->fbtftops.write = fbtft_write_gpio16_wr;
1390 	}
1391 
1392 	/* 9-bit SPI setup */
1393 	if (par->spi && display->buswidth == 9) {
1394 		if (par->spi->master->bits_per_word_mask & SPI_BPW_MASK(9)) {
1395 			par->spi->bits_per_word = 9;
1396 		} else {
1397 			dev_warn(&par->spi->dev,
1398 				 "9-bit SPI not available, emulating using 8-bit.\n");
1399 			/* allocate buffer with room for dc bits */
1400 			par->extra = devm_kzalloc(par->info->device,
1401 						  par->txbuf.len +
1402 						  (par->txbuf.len / 8) + 8,
1403 						  GFP_KERNEL);
1404 			if (!par->extra) {
1405 				ret = -ENOMEM;
1406 				goto out_release;
1407 			}
1408 			par->fbtftops.write = fbtft_write_spi_emulate_9;
1409 		}
1410 	}
1411 
1412 	if (!par->fbtftops.verify_gpios)
1413 		par->fbtftops.verify_gpios = fbtft_verify_gpios;
1414 
1415 	/* make sure we still use the driver provided functions */
1416 	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
1417 
1418 	/* use init_sequence if provided */
1419 	if (par->init_sequence)
1420 		par->fbtftops.init_display = fbtft_init_display;
1421 
1422 	/* use platform_data provided functions above all */
1423 	fbtft_merge_fbtftops(&par->fbtftops, &pdata->display.fbtftops);
1424 
1425 	ret = fbtft_register_framebuffer(info);
1426 	if (ret < 0)
1427 		goto out_release;
1428 
1429 	return 0;
1430 
1431 out_release:
1432 	fbtft_framebuffer_release(info);
1433 
1434 	return ret;
1435 }
1436 EXPORT_SYMBOL(fbtft_probe_common);
1437 
1438 /**
1439  * fbtft_remove_common() - Generic device remove() helper function
1440  * @dev: Device
1441  * @info: Framebuffer
1442  *
1443  * Unregisters and releases the framebuffer
1444  *
1445  * Return: 0 if successful, negative if error
1446  */
1447 int fbtft_remove_common(struct device *dev, struct fb_info *info)
1448 {
1449 	struct fbtft_par *par;
1450 
1451 	if (!info)
1452 		return -EINVAL;
1453 	par = info->par;
1454 	if (par)
1455 		fbtft_par_dbg(DEBUG_DRIVER_INIT_FUNCTIONS, par,
1456 			      "%s()\n", __func__);
1457 	fbtft_unregister_framebuffer(info);
1458 	fbtft_framebuffer_release(info);
1459 
1460 	return 0;
1461 }
1462 EXPORT_SYMBOL(fbtft_remove_common);
1463 
1464 MODULE_LICENSE("GPL");
1465