Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1327 insertions, 0 deletions

diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
new file mode 100644
index 000000000..afaba94d1
--- /dev/null
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -0,0 +1,1327 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2013 Noralf Tronnes
+ *
+ * This driver is inspired by:
+ *   st7735fb.c, Copyright (C) 2011, Matt Porter
+ *   broadsheetfb.c, Copyright (C) 2008, Jaya Kumar
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/fb.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/backlight.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/spinlock.h>
+
+#include <video/mipi_display.h>
+
+#include "fbtft.h"
+#include "internal.h"
+
+static unsigned long debug;
+module_param(debug, ulong, 0000);
+MODULE_PARM_DESC(debug, "override device debug level");
+
+int fbtft_write_buf_dc(struct fbtft_par *par, void *buf, size_t len, int dc)
+{
+	int ret;
+
+	gpiod_set_value(par->gpio.dc, dc);
+
+	ret = par->fbtftops.write(par, buf, len);
+	if (ret < 0)
+		dev_err(par->info->device,
+			"write() failed and returned %d\n", ret);
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_write_buf_dc);
+
+void fbtft_dbg_hex(const struct device *dev, int groupsize,
+		   const void *buf, size_t len, const char *fmt, ...)
+{
+	va_list args;
+	static char textbuf[512];
+	char *text = textbuf;
+	size_t text_len;
+
+	va_start(args, fmt);
+	text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
+	va_end(args);
+
+	hex_dump_to_buffer(buf, len, 32, groupsize, text + text_len,
+			   512 - text_len, false);
+
+	if (len > 32)
+		dev_info(dev, "%s ...\n", text);
+	else
+		dev_info(dev, "%s\n", text);
+}
+EXPORT_SYMBOL(fbtft_dbg_hex);
+
+static int fbtft_request_one_gpio(struct fbtft_par *par,
+				  const char *name, int index,
+				  struct gpio_desc **gpiop)
+{
+	struct device *dev = par->info->device;
+
+	*gpiop = devm_gpiod_get_index_optional(dev, name, index,
+					       GPIOD_OUT_LOW);
+	if (IS_ERR(*gpiop))
+		return dev_err_probe(dev, PTR_ERR(*gpiop), "Failed to request %s GPIO\n", name);
+
+	fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO\n",
+		      __func__, name);
+
+	return 0;
+}
+
+static int fbtft_request_gpios(struct fbtft_par *par)
+{
+	int i;
+	int ret;
+
+	ret = fbtft_request_one_gpio(par, "reset", 0, &par->gpio.reset);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "dc", 0, &par->gpio.dc);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "rd", 0, &par->gpio.rd);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "wr", 0, &par->gpio.wr);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "cs", 0, &par->gpio.cs);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "latch", 0, &par->gpio.latch);
+	if (ret)
+		return ret;
+	for (i = 0; i < 16; i++) {
+		ret = fbtft_request_one_gpio(par, "db", i,
+					     &par->gpio.db[i]);
+		if (ret)
+			return ret;
+		ret = fbtft_request_one_gpio(par, "led", i,
+					     &par->gpio.led[i]);
+		if (ret)
+			return ret;
+		ret = fbtft_request_one_gpio(par, "aux", i,
+					     &par->gpio.aux[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int fbtft_backlight_update_status(struct backlight_device *bd)
+{
+	struct fbtft_par *par = bl_get_data(bd);
+	bool polarity = par->polarity;
+
+	fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+		      "%s: polarity=%d, power=%d, fb_blank=%d\n",
+		      __func__, polarity, bd->props.power, bd->props.fb_blank);
+
+	if (!backlight_is_blank(bd))
+		gpiod_set_value(par->gpio.led[0], polarity);
+	else
+		gpiod_set_value(par->gpio.led[0], !polarity);
+
+	return 0;
+}
+
+static int fbtft_backlight_get_brightness(struct backlight_device *bd)
+{
+	return bd->props.brightness;
+}
+
+void fbtft_unregister_backlight(struct fbtft_par *par)
+{
+	if (par->info->bl_dev) {
+		par->info->bl_dev->props.power = FB_BLANK_POWERDOWN;
+		backlight_update_status(par->info->bl_dev);
+		backlight_device_unregister(par->info->bl_dev);
+		par->info->bl_dev = NULL;
+	}
+}
+EXPORT_SYMBOL(fbtft_unregister_backlight);
+
+static const struct backlight_ops fbtft_bl_ops = {
+	.get_brightness	= fbtft_backlight_get_brightness,
+	.update_status	= fbtft_backlight_update_status,
+};
+
+void fbtft_register_backlight(struct fbtft_par *par)
+{
+	struct backlight_device *bd;
+	struct backlight_properties bl_props = { 0, };
+
+	if (!par->gpio.led[0]) {
+		fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+			      "%s(): led pin not set, exiting.\n", __func__);
+		return;
+	}
+
+	bl_props.type = BACKLIGHT_RAW;
+	/* Assume backlight is off, get polarity from current state of pin */
+	bl_props.power = FB_BLANK_POWERDOWN;
+	if (!gpiod_get_value(par->gpio.led[0]))
+		par->polarity = true;
+
+	bd = backlight_device_register(dev_driver_string(par->info->device),
+				       par->info->device, par,
+				       &fbtft_bl_ops, &bl_props);
+	if (IS_ERR(bd)) {
+		dev_err(par->info->device,
+			"cannot register backlight device (%ld)\n",
+			PTR_ERR(bd));
+		return;
+	}
+	par->info->bl_dev = bd;
+
+	if (!par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
+}
+EXPORT_SYMBOL(fbtft_register_backlight);
+
+static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
+			       int ye)
+{
+	write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
+		  (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
+
+	write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
+		  (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
+
+	write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
+}
+
+static void fbtft_reset(struct fbtft_par *par)
+{
+	if (!par->gpio.reset)
+		return;
+
+	fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
+
+	gpiod_set_value_cansleep(par->gpio.reset, 1);
+	usleep_range(20, 40);
+	gpiod_set_value_cansleep(par->gpio.reset, 0);
+	msleep(120);
+
+	gpiod_set_value_cansleep(par->gpio.cs, 1);  /* Activate chip */
+}
+
+static void fbtft_update_display(struct fbtft_par *par, unsigned int start_line,
+				 unsigned int end_line)
+{
+	size_t offset, len;
+	ktime_t ts_start, ts_end;
+	long fps, throughput;
+	bool timeit = false;
+	int ret = 0;
+
+	if (unlikely(par->debug & (DEBUG_TIME_FIRST_UPDATE |
+			DEBUG_TIME_EACH_UPDATE))) {
+		if ((par->debug & DEBUG_TIME_EACH_UPDATE) ||
+		    ((par->debug & DEBUG_TIME_FIRST_UPDATE) &&
+		    !par->first_update_done)) {
+			ts_start = ktime_get();
+			timeit = true;
+		}
+	}
+
+	/* Sanity checks */
+	if (start_line > end_line) {
+		dev_warn(par->info->device,
+			 "%s: start_line=%u is larger than end_line=%u. Shouldn't happen, will do full display update\n",
+			 __func__, start_line, end_line);
+		start_line = 0;
+		end_line = par->info->var.yres - 1;
+	}
+	if (start_line > par->info->var.yres - 1 ||
+	    end_line > par->info->var.yres - 1) {
+		dev_warn(par->info->device,
+			 "%s: start_line=%u or end_line=%u is larger than max=%d. Shouldn't happen, will do full display update\n",
+			 __func__, start_line,
+			 end_line, par->info->var.yres - 1);
+		start_line = 0;
+		end_line = par->info->var.yres - 1;
+	}
+
+	fbtft_par_dbg(DEBUG_UPDATE_DISPLAY, par, "%s(start_line=%u, end_line=%u)\n",
+		      __func__, start_line, end_line);
+
+	if (par->fbtftops.set_addr_win)
+		par->fbtftops.set_addr_win(par, 0, start_line,
+				par->info->var.xres - 1, end_line);
+
+	offset = start_line * par->info->fix.line_length;
+	len = (end_line - start_line + 1) * par->info->fix.line_length;
+	ret = par->fbtftops.write_vmem(par, offset, len);
+	if (ret < 0)
+		dev_err(par->info->device,
+			"%s: write_vmem failed to update display buffer\n",
+			__func__);
+
+	if (unlikely(timeit)) {
+		ts_end = ktime_get();
+		if (!ktime_to_ns(par->update_time))
+			par->update_time = ts_start;
+
+		fps = ktime_us_delta(ts_start, par->update_time);
+		par->update_time = ts_start;
+		fps = fps ? 1000000 / fps : 0;
+
+		throughput = ktime_us_delta(ts_end, ts_start);
+		throughput = throughput ? (len * 1000) / throughput : 0;
+		throughput = throughput * 1000 / 1024;
+
+		dev_info(par->info->device,
+			 "Display update: %ld kB/s, fps=%ld\n",
+			 throughput, fps);
+		par->first_update_done = true;
+	}
+}
+
+static void fbtft_mkdirty(struct fb_info *info, int y, int height)
+{
+	struct fbtft_par *par = info->par;
+	struct fb_deferred_io *fbdefio = info->fbdefio;
+
+	/* special case, needed ? */
+	if (y == -1) {
+		y = 0;
+		height = info->var.yres;
+	}
+
+	/* Mark display lines/area as dirty */
+	spin_lock(&par->dirty_lock);
+	if (y < par->dirty_lines_start)
+		par->dirty_lines_start = y;
+	if (y + height - 1 > par->dirty_lines_end)
+		par->dirty_lines_end = y + height - 1;
+	spin_unlock(&par->dirty_lock);
+
+	/* Schedule deferred_io to update display (no-op if already on queue)*/
+	schedule_delayed_work(&info->deferred_work, fbdefio->delay);
+}
+
+static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagereflist)
+{
+	struct fbtft_par *par = info->par;
+	unsigned int dirty_lines_start, dirty_lines_end;
+	struct fb_deferred_io_pageref *pageref;
+	unsigned int y_low = 0, y_high = 0;
+	int count = 0;
+
+	spin_lock(&par->dirty_lock);
+	dirty_lines_start = par->dirty_lines_start;
+	dirty_lines_end = par->dirty_lines_end;
+	/* set display line markers as clean */
+	par->dirty_lines_start = par->info->var.yres - 1;
+	par->dirty_lines_end = 0;
+	spin_unlock(&par->dirty_lock);
+
+	/* Mark display lines as dirty */
+	list_for_each_entry(pageref, pagereflist, list) {
+		count++;
+		y_low = pageref->offset / info->fix.line_length;
+		y_high = (pageref->offset + PAGE_SIZE - 1) / info->fix.line_length;
+		dev_dbg(info->device,
+			"page->index=%lu y_low=%d y_high=%d\n",
+			pageref->page->index, y_low, y_high);
+		if (y_high > info->var.yres - 1)
+			y_high = info->var.yres - 1;
+		if (y_low < dirty_lines_start)
+			dirty_lines_start = y_low;
+		if (y_high > dirty_lines_end)
+			dirty_lines_end = y_high;
+	}
+
+	par->fbtftops.update_display(info->par,
+					dirty_lines_start, dirty_lines_end);
+}
+
+static void fbtft_fb_fillrect(struct fb_info *info,
+			      const struct fb_fillrect *rect)
+{
+	struct fbtft_par *par = info->par;
+
+	dev_dbg(info->dev,
+		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
+		__func__, rect->dx, rect->dy, rect->width, rect->height);
+	sys_fillrect(info, rect);
+
+	par->fbtftops.mkdirty(info, rect->dy, rect->height);
+}
+
+static void fbtft_fb_copyarea(struct fb_info *info,
+			      const struct fb_copyarea *area)
+{
+	struct fbtft_par *par = info->par;
+
+	dev_dbg(info->dev,
+		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
+		__func__,  area->dx, area->dy, area->width, area->height);
+	sys_copyarea(info, area);
+
+	par->fbtftops.mkdirty(info, area->dy, area->height);
+}
+
+static void fbtft_fb_imageblit(struct fb_info *info,
+			       const struct fb_image *image)
+{
+	struct fbtft_par *par = info->par;
+
+	dev_dbg(info->dev,
+		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
+		__func__,  image->dx, image->dy, image->width, image->height);
+	sys_imageblit(info, image);
+
+	par->fbtftops.mkdirty(info, image->dy, image->height);
+}
+
+static ssize_t fbtft_fb_write(struct fb_info *info, const char __user *buf,
+			      size_t count, loff_t *ppos)
+{
+	struct fbtft_par *par = info->par;
+	ssize_t res;
+
+	dev_dbg(info->dev,
+		"%s: count=%zd, ppos=%llu\n", __func__,  count, *ppos);
+	res = fb_sys_write(info, buf, count, ppos);
+
+	/* TODO: only mark changed area update all for now */
+	par->fbtftops.mkdirty(info, -1, 0);
+
+	return res;
+}
+
+/* from pxafb.c */
+static unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf)
+{
+	chan &= 0xffff;
+	chan >>= 16 - bf->length;
+	return chan << bf->offset;
+}
+
+static int fbtft_fb_setcolreg(unsigned int regno, unsigned int red,
+			      unsigned int green, unsigned int blue,
+			      unsigned int transp, struct fb_info *info)
+{
+	unsigned int val;
+	int ret = 1;
+
+	dev_dbg(info->dev,
+		"%s(regno=%u, red=0x%X, green=0x%X, blue=0x%X, trans=0x%X)\n",
+		__func__, regno, red, green, blue, transp);
+
+	switch (info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		if (regno < 16) {
+			u32 *pal = info->pseudo_palette;
+
+			val  = chan_to_field(red,   &info->var.red);
+			val |= chan_to_field(green, &info->var.green);
+			val |= chan_to_field(blue,  &info->var.blue);
+
+			pal[regno] = val;
+			ret = 0;
+		}
+		break;
+	}
+	return ret;
+}
+
+static int fbtft_fb_blank(int blank, struct fb_info *info)
+{
+	struct fbtft_par *par = info->par;
+	int ret = -EINVAL;
+
+	dev_dbg(info->dev, "%s(blank=%d)\n",
+		__func__, blank);
+
+	if (!par->fbtftops.blank)
+		return ret;
+
+	switch (blank) {
+	case FB_BLANK_POWERDOWN:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_NORMAL:
+		ret = par->fbtftops.blank(par, true);
+		break;
+	case FB_BLANK_UNBLANK:
+		ret = par->fbtftops.blank(par, false);
+		break;
+	}
+	return ret;
+}
+
+static void fbtft_merge_fbtftops(struct fbtft_ops *dst, struct fbtft_ops *src)
+{
+	if (src->write)
+		dst->write = src->write;
+	if (src->read)
+		dst->read = src->read;
+	if (src->write_vmem)
+		dst->write_vmem = src->write_vmem;
+	if (src->write_register)
+		dst->write_register = src->write_register;
+	if (src->set_addr_win)
+		dst->set_addr_win = src->set_addr_win;
+	if (src->reset)
+		dst->reset = src->reset;
+	if (src->mkdirty)
+		dst->mkdirty = src->mkdirty;
+	if (src->update_display)
+		dst->update_display = src->update_display;
+	if (src->init_display)
+		dst->init_display = src->init_display;
+	if (src->blank)
+		dst->blank = src->blank;
+	if (src->request_gpios_match)
+		dst->request_gpios_match = src->request_gpios_match;
+	if (src->request_gpios)
+		dst->request_gpios = src->request_gpios;
+	if (src->verify_gpios)
+		dst->verify_gpios = src->verify_gpios;
+	if (src->register_backlight)
+		dst->register_backlight = src->register_backlight;
+	if (src->unregister_backlight)
+		dst->unregister_backlight = src->unregister_backlight;
+	if (src->set_var)
+		dst->set_var = src->set_var;
+	if (src->set_gamma)
+		dst->set_gamma = src->set_gamma;
+}
+
+/**
+ * fbtft_framebuffer_alloc - creates a new frame buffer info structure
+ *
+ * @display: pointer to structure describing the display
+ * @dev: pointer to the device for this fb, this can be NULL
+ * @pdata: platform data for the display in use
+ *
+ * Creates a new frame buffer info structure.
+ *
+ * Also creates and populates the following structures:
+ *   info->fbops
+ *   info->fbdefio
+ *   info->pseudo_palette
+ *   par->fbtftops
+ *   par->txbuf
+ *
+ * Returns the new structure, or NULL if an error occurred.
+ *
+ */
+struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
+					struct device *dev,
+					struct fbtft_platform_data *pdata)
+{
+	struct fb_info *info;
+	struct fbtft_par *par;
+	struct fb_ops *fbops = NULL;
+	struct fb_deferred_io *fbdefio = NULL;
+	u8 *vmem = NULL;
+	void *txbuf = NULL;
+	void *buf = NULL;
+	unsigned int width;
+	unsigned int height;
+	int txbuflen = display->txbuflen;
+	unsigned int bpp = display->bpp;
+	unsigned int fps = display->fps;
+	int vmem_size;
+	const s16 *init_sequence = display->init_sequence;
+	char *gamma = display->gamma;
+	u32 *gamma_curves = NULL;
+
+	/* sanity check */
+	if (display->gamma_num * display->gamma_len >
+			FBTFT_GAMMA_MAX_VALUES_TOTAL) {
+		dev_err(dev, "FBTFT_GAMMA_MAX_VALUES_TOTAL=%d is exceeded\n",
+			FBTFT_GAMMA_MAX_VALUES_TOTAL);
+		return NULL;
+	}
+
+	/* defaults */
+	if (!fps)
+		fps = 20;
+	if (!bpp)
+		bpp = 16;
+
+	if (!pdata) {
+		dev_err(dev, "platform data is missing\n");
+		return NULL;
+	}
+
+	/* override driver values? */
+	if (pdata->fps)
+		fps = pdata->fps;
+	if (pdata->txbuflen)
+		txbuflen = pdata->txbuflen;
+	if (pdata->display.init_sequence)
+		init_sequence = pdata->display.init_sequence;
+	if (pdata->gamma)
+		gamma = pdata->gamma;
+	if (pdata->display.debug)
+		display->debug = pdata->display.debug;
+	if (pdata->display.backlight)
+		display->backlight = pdata->display.backlight;
+	if (pdata->display.width)
+		display->width = pdata->display.width;
+	if (pdata->display.height)
+		display->height = pdata->display.height;
+	if (pdata->display.buswidth)
+		display->buswidth = pdata->display.buswidth;
+	if (pdata->display.regwidth)
+		display->regwidth = pdata->display.regwidth;
+
+	display->debug |= debug;
+	fbtft_expand_debug_value(&display->debug);
+
+	switch (pdata->rotate) {
+	case 90:
+	case 270:
+		width =  display->height;
+		height = display->width;
+		break;
+	default:
+		width =  display->width;
+		height = display->height;
+	}
+
+	vmem_size = display->width * display->height * bpp / 8;
+	vmem = vzalloc(vmem_size);
+	if (!vmem)
+		goto alloc_fail;
+
+	fbops = devm_kzalloc(dev, sizeof(struct fb_ops), GFP_KERNEL);
+	if (!fbops)
+		goto alloc_fail;
+
+	fbdefio = devm_kzalloc(dev, sizeof(struct fb_deferred_io), GFP_KERNEL);
+	if (!fbdefio)
+		goto alloc_fail;
+
+	buf = devm_kzalloc(dev, 128, GFP_KERNEL);
+	if (!buf)
+		goto alloc_fail;
+
+	if (display->gamma_num && display->gamma_len) {
+		gamma_curves = devm_kcalloc(dev,
+					    display->gamma_num *
+					    display->gamma_len,
+					    sizeof(gamma_curves[0]),
+					    GFP_KERNEL);
+		if (!gamma_curves)
+			goto alloc_fail;
+	}
+
+	info = framebuffer_alloc(sizeof(struct fbtft_par), dev);
+	if (!info)
+		goto alloc_fail;
+
+	info->screen_buffer = vmem;
+	info->fbops = fbops;
+	info->fbdefio = fbdefio;
+
+	fbops->owner        =      dev->driver->owner;
+	fbops->fb_read      =      fb_sys_read;
+	fbops->fb_write     =      fbtft_fb_write;
+	fbops->fb_fillrect  =      fbtft_fb_fillrect;
+	fbops->fb_copyarea  =      fbtft_fb_copyarea;
+	fbops->fb_imageblit =      fbtft_fb_imageblit;
+	fbops->fb_setcolreg =      fbtft_fb_setcolreg;
+	fbops->fb_blank     =      fbtft_fb_blank;
+	fbops->fb_mmap      =      fb_deferred_io_mmap;
+
+	fbdefio->delay =            HZ / fps;
+	fbdefio->sort_pagereflist = true;
+	fbdefio->deferred_io =      fbtft_deferred_io;
+
+	snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
+	info->fix.type =           FB_TYPE_PACKED_PIXELS;
+	info->fix.visual =         FB_VISUAL_TRUECOLOR;
+	info->fix.xpanstep =	   0;
+	info->fix.ypanstep =	   0;
+	info->fix.ywrapstep =	   0;
+	info->fix.line_length =    width * bpp / 8;
+	info->fix.accel =          FB_ACCEL_NONE;
+	info->fix.smem_len =       vmem_size;
+	fb_deferred_io_init(info);
+
+	info->var.rotate =         pdata->rotate;
+	info->var.xres =           width;
+	info->var.yres =           height;
+	info->var.xres_virtual =   info->var.xres;
+	info->var.yres_virtual =   info->var.yres;
+	info->var.bits_per_pixel = bpp;
+	info->var.nonstd =         1;
+
+	/* RGB565 */
+	info->var.red.offset =     11;
+	info->var.red.length =     5;
+	info->var.green.offset =   5;
+	info->var.green.length =   6;
+	info->var.blue.offset =    0;
+	info->var.blue.length =    5;
+	info->var.transp.offset =  0;
+	info->var.transp.length =  0;
+
+	info->flags =              FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
+
+	par = info->par;
+	par->info = info;
+	par->pdata = pdata;
+	par->debug = display->debug;
+	par->buf = buf;
+	spin_lock_init(&par->dirty_lock);
+	par->bgr = pdata->bgr;
+	par->startbyte = pdata->startbyte;
+	par->init_sequence = init_sequence;
+	par->gamma.curves = gamma_curves;
+	par->gamma.num_curves = display->gamma_num;
+	par->gamma.num_values = display->gamma_len;
+	mutex_init(&par->gamma.lock);
+	info->pseudo_palette = par->pseudo_palette;
+
+	if (par->gamma.curves && gamma) {
+		if (fbtft_gamma_parse_str(par, par->gamma.curves, gamma,
+					  strlen(gamma)))
+			goto release_framebuf;
+	}
+
+	/* Transmit buffer */
+	if (txbuflen == -1)
+		txbuflen = vmem_size + 2; /* add in case startbyte is used */
+	if (txbuflen >= vmem_size + 2)
+		txbuflen = 0;
+
+#ifdef __LITTLE_ENDIAN
+	if ((!txbuflen) && (bpp > 8))
+		txbuflen = PAGE_SIZE; /* need buffer for byteswapping */
+#endif
+
+	if (txbuflen > 0) {
+		txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
+		if (!txbuf)
+			goto release_framebuf;
+		par->txbuf.buf = txbuf;
+		par->txbuf.len = txbuflen;
+	}
+
+	/* default fbtft operations */
+	par->fbtftops.write = fbtft_write_spi;
+	par->fbtftops.read = fbtft_read_spi;
+	par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
+	par->fbtftops.write_register = fbtft_write_reg8_bus8;
+	par->fbtftops.set_addr_win = fbtft_set_addr_win;
+	par->fbtftops.reset = fbtft_reset;
+	par->fbtftops.mkdirty = fbtft_mkdirty;
+	par->fbtftops.update_display = fbtft_update_display;
+	if (display->backlight)
+		par->fbtftops.register_backlight = fbtft_register_backlight;
+
+	/* use driver provided functions */
+	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
+
+	return info;
+
+release_framebuf:
+	framebuffer_release(info);
+
+alloc_fail:
+	vfree(vmem);
+
+	return NULL;
+}
+EXPORT_SYMBOL(fbtft_framebuffer_alloc);
+
+/**
+ * fbtft_framebuffer_release - frees up all memory used by the framebuffer
+ *
+ * @info: frame buffer info structure
+ *
+ */
+void fbtft_framebuffer_release(struct fb_info *info)
+{
+	fb_deferred_io_cleanup(info);
+	vfree(info->screen_buffer);
+	framebuffer_release(info);
+}
+EXPORT_SYMBOL(fbtft_framebuffer_release);
+
+/**
+ *	fbtft_register_framebuffer - registers a tft frame buffer device
+ *	@fb_info: frame buffer info structure
+ *
+ *  Sets SPI driverdata if needed
+ *  Requests needed gpios.
+ *  Initializes display
+ *  Updates display.
+ *	Registers a frame buffer device @fb_info.
+ *
+ *	Returns negative errno on error, or zero for success.
+ *
+ */
+int fbtft_register_framebuffer(struct fb_info *fb_info)
+{
+	int ret;
+	char text1[50] = "";
+	char text2[50] = "";
+	struct fbtft_par *par = fb_info->par;
+	struct spi_device *spi = par->spi;
+
+	/* sanity checks */
+	if (!par->fbtftops.init_display) {
+		dev_err(fb_info->device, "missing fbtftops.init_display()\n");
+		return -EINVAL;
+	}
+
+	if (spi)
+		spi_set_drvdata(spi, fb_info);
+	if (par->pdev)
+		platform_set_drvdata(par->pdev, fb_info);
+
+	ret = par->fbtftops.request_gpios(par);
+	if (ret < 0)
+		goto reg_fail;
+
+	if (par->fbtftops.verify_gpios) {
+		ret = par->fbtftops.verify_gpios(par);
+		if (ret < 0)
+			goto reg_fail;
+	}
+
+	ret = par->fbtftops.init_display(par);
+	if (ret < 0)
+		goto reg_fail;
+	if (par->fbtftops.set_var) {
+		ret = par->fbtftops.set_var(par);
+		if (ret < 0)
+			goto reg_fail;
+	}
+
+	/* update the entire display */
+	par->fbtftops.update_display(par, 0, par->info->var.yres - 1);
+
+	if (par->fbtftops.set_gamma && par->gamma.curves) {
+		ret = par->fbtftops.set_gamma(par, par->gamma.curves);
+		if (ret)
+			goto reg_fail;
+	}
+
+	if (par->fbtftops.register_backlight)
+		par->fbtftops.register_backlight(par);
+
+	ret = register_framebuffer(fb_info);
+	if (ret < 0)
+		goto reg_fail;
+
+	fbtft_sysfs_init(par);
+
+	if (par->txbuf.buf && par->txbuf.len >= 1024)
+		sprintf(text1, ", %zu KiB buffer memory", par->txbuf.len >> 10);
+	if (spi)
+		sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
+			spi->chip_select, spi->max_speed_hz / 1000000);
+	dev_info(fb_info->dev,
+		 "%s frame buffer, %dx%d, %d KiB video memory%s, fps=%lu%s\n",
+		 fb_info->fix.id, fb_info->var.xres, fb_info->var.yres,
+		 fb_info->fix.smem_len >> 10, text1,
+		 HZ / fb_info->fbdefio->delay, text2);
+
+	/* Turn on backlight if available */
+	if (fb_info->bl_dev) {
+		fb_info->bl_dev->props.power = FB_BLANK_UNBLANK;
+		fb_info->bl_dev->ops->update_status(fb_info->bl_dev);
+	}
+
+	return 0;
+
+reg_fail:
+	if (par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight(par);
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_register_framebuffer);
+
+/**
+ *	fbtft_unregister_framebuffer - releases a tft frame buffer device
+ *	@fb_info: frame buffer info structure
+ *
+ *  Frees SPI driverdata if needed
+ *  Frees gpios.
+ *	Unregisters frame buffer device.
+ *
+ */
+int fbtft_unregister_framebuffer(struct fb_info *fb_info)
+{
+	struct fbtft_par *par = fb_info->par;
+
+	if (par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight(par);
+	fbtft_sysfs_exit(par);
+	unregister_framebuffer(fb_info);
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_unregister_framebuffer);
+
+/**
+ * fbtft_init_display_from_property() - Device Tree init_display() function
+ * @par: Driver data
+ *
+ * Return: 0 if successful, negative if error
+ */
+static int fbtft_init_display_from_property(struct fbtft_par *par)
+{
+	struct device *dev = par->info->device;
+	int buf[64], count, index, i, j, ret;
+	u32 *values;
+	u32 val;
+
+	count = device_property_count_u32(dev, "init");
+	if (count < 0)
+		return count;
+	if (count == 0)
+		return -EINVAL;
+
+	values = kmalloc_array(count + 1, sizeof(*values), GFP_KERNEL);
+	if (!values)
+		return -ENOMEM;
+
+	ret = device_property_read_u32_array(dev, "init", values, count);
+	if (ret)
+		goto out_free;
+
+	par->fbtftops.reset(par);
+
+	index = -1;
+	val = values[++index];
+
+	while (index < count) {
+		if (val & FBTFT_OF_INIT_CMD) {
+			val &= 0xFFFF;
+			i = 0;
+			while ((index < count) && !(val & 0xFFFF0000)) {
+				if (i > 63) {
+					dev_err(dev,
+						"%s: Maximum register values exceeded\n",
+						__func__);
+					ret = -EINVAL;
+					goto out_free;
+				}
+				buf[i++] = val;
+				val = values[++index];
+			}
+			/* make debug message */
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: write_register:\n");
+			for (j = 0; j < i; j++)
+				fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+					      "buf[%d] = %02X\n", j, buf[j]);
+
+			par->fbtftops.write_register(par, i,
+				buf[0], buf[1], buf[2], buf[3],
+				buf[4], buf[5], buf[6], buf[7],
+				buf[8], buf[9], buf[10], buf[11],
+				buf[12], buf[13], buf[14], buf[15],
+				buf[16], buf[17], buf[18], buf[19],
+				buf[20], buf[21], buf[22], buf[23],
+				buf[24], buf[25], buf[26], buf[27],
+				buf[28], buf[29], buf[30], buf[31],
+				buf[32], buf[33], buf[34], buf[35],
+				buf[36], buf[37], buf[38], buf[39],
+				buf[40], buf[41], buf[42], buf[43],
+				buf[44], buf[45], buf[46], buf[47],
+				buf[48], buf[49], buf[50], buf[51],
+				buf[52], buf[53], buf[54], buf[55],
+				buf[56], buf[57], buf[58], buf[59],
+				buf[60], buf[61], buf[62], buf[63]);
+		} else if (val & FBTFT_OF_INIT_DELAY) {
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: msleep(%u)\n", val & 0xFFFF);
+			msleep(val & 0xFFFF);
+			val = values[++index];
+		} else {
+			dev_err(dev, "illegal init value 0x%X\n", val);
+			ret = -EINVAL;
+			goto out_free;
+		}
+	}
+
+out_free:
+	kfree(values);
+	return ret;
+}
+
+/**
+ * fbtft_init_display() - Generic init_display() function
+ * @par: Driver data
+ *
+ * Uses par->init_sequence to do the initialization
+ *
+ * Return: 0 if successful, negative if error
+ */
+int fbtft_init_display(struct fbtft_par *par)
+{
+	int buf[64];
+	int i;
+	int j;
+
+	/* sanity check */
+	if (!par->init_sequence) {
+		dev_err(par->info->device,
+			"error: init_sequence is not set\n");
+		return -EINVAL;
+	}
+
+	/* make sure stop marker exists */
+	for (i = 0; i < FBTFT_MAX_INIT_SEQUENCE; i++) {
+		if (par->init_sequence[i] == -3)
+			break;
+	}
+
+	if (i == FBTFT_MAX_INIT_SEQUENCE) {
+		dev_err(par->info->device,
+			"missing stop marker at end of init sequence\n");
+		return -EINVAL;
+	}
+
+	par->fbtftops.reset(par);
+
+	i = 0;
+	while (i < FBTFT_MAX_INIT_SEQUENCE) {
+		if (par->init_sequence[i] == -3) {
+			/* done */
+			return 0;
+		}
+		if (par->init_sequence[i] >= 0) {
+			dev_err(par->info->device,
+				"missing delimiter at position %d\n", i);
+			return -EINVAL;
+		}
+		if (par->init_sequence[i + 1] < 0) {
+			dev_err(par->info->device,
+				"missing value after delimiter %d at position %d\n",
+				par->init_sequence[i], i);
+			return -EINVAL;
+		}
+		switch (par->init_sequence[i]) {
+		case -1:
+			i++;
+
+			/* make debug message */
+			for (j = 0; par->init_sequence[i + 1 + j] >= 0; j++)
+				;
+
+			fbtft_par_dbg_hex(DEBUG_INIT_DISPLAY, par, par->info->device,
+					  s16, &par->init_sequence[i + 1], j,
+					  "init: write(0x%02X)", par->init_sequence[i]);
+
+			/* Write */
+			j = 0;
+			while (par->init_sequence[i] >= 0) {
+				if (j > 63) {
+					dev_err(par->info->device,
+						"%s: Maximum register values exceeded\n",
+						__func__);
+					return -EINVAL;
+				}
+				buf[j++] = par->init_sequence[i++];
+			}
+			par->fbtftops.write_register(par, j,
+				buf[0], buf[1], buf[2], buf[3],
+				buf[4], buf[5], buf[6], buf[7],
+				buf[8], buf[9], buf[10], buf[11],
+				buf[12], buf[13], buf[14], buf[15],
+				buf[16], buf[17], buf[18], buf[19],
+				buf[20], buf[21], buf[22], buf[23],
+				buf[24], buf[25], buf[26], buf[27],
+				buf[28], buf[29], buf[30], buf[31],
+				buf[32], buf[33], buf[34], buf[35],
+				buf[36], buf[37], buf[38], buf[39],
+				buf[40], buf[41], buf[42], buf[43],
+				buf[44], buf[45], buf[46], buf[47],
+				buf[48], buf[49], buf[50], buf[51],
+				buf[52], buf[53], buf[54], buf[55],
+				buf[56], buf[57], buf[58], buf[59],
+				buf[60], buf[61], buf[62], buf[63]);
+			break;
+		case -2:
+			i++;
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: mdelay(%d)\n",
+				      par->init_sequence[i]);
+			mdelay(par->init_sequence[i++]);
+			break;
+		default:
+			dev_err(par->info->device,
+				"unknown delimiter %d at position %d\n",
+				par->init_sequence[i], i);
+			return -EINVAL;
+		}
+	}
+
+	dev_err(par->info->device,
+		"%s: something is wrong. Shouldn't get here.\n", __func__);
+	return -EINVAL;
+}
+EXPORT_SYMBOL(fbtft_init_display);
+
+/**
+ * fbtft_verify_gpios() - Generic verify_gpios() function
+ * @par: Driver data
+ *
+ * Uses @spi, @pdev and @buswidth to determine which GPIOs is needed
+ *
+ * Return: 0 if successful, negative if error
+ */
+static int fbtft_verify_gpios(struct fbtft_par *par)
+{
+	struct fbtft_platform_data *pdata = par->pdata;
+	int i;
+
+	fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
+
+	if (pdata->display.buswidth != 9 &&  par->startbyte == 0 &&
+	    !par->gpio.dc) {
+		dev_err(par->info->device,
+			"Missing info about 'dc' gpio. Aborting.\n");
+		return -EINVAL;
+	}
+
+	if (!par->pdev)
+		return 0;
+
+	if (!par->gpio.wr) {
+		dev_err(par->info->device, "Missing 'wr' gpio. Aborting.\n");
+		return -EINVAL;
+	}
+	for (i = 0; i < pdata->display.buswidth; i++) {
+		if (!par->gpio.db[i]) {
+			dev_err(par->info->device,
+				"Missing 'db%02d' gpio. Aborting.\n", i);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/* returns 0 if the property is not present */
+static u32 fbtft_property_value(struct device *dev, const char *propname)
+{
+	int ret;
+	u32 val = 0;
+
+	ret = device_property_read_u32(dev, propname, &val);
+	if (ret == 0)
+		dev_info(dev, "%s: %s = %u\n", __func__, propname, val);
+
+	return val;
+}
+
+static struct fbtft_platform_data *fbtft_properties_read(struct device *dev)
+{
+	struct fbtft_platform_data *pdata;
+
+	if (!dev_fwnode(dev)) {
+		dev_err(dev, "Missing platform data or properties\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	pdata->display.width = fbtft_property_value(dev, "width");
+	pdata->display.height = fbtft_property_value(dev, "height");
+	pdata->display.regwidth = fbtft_property_value(dev, "regwidth");
+	pdata->display.buswidth = fbtft_property_value(dev, "buswidth");
+	pdata->display.backlight = fbtft_property_value(dev, "backlight");
+	pdata->display.bpp = fbtft_property_value(dev, "bpp");
+	pdata->display.debug = fbtft_property_value(dev, "debug");
+	pdata->rotate = fbtft_property_value(dev, "rotate");
+	pdata->bgr = device_property_read_bool(dev, "bgr");
+	pdata->fps = fbtft_property_value(dev, "fps");
+	pdata->txbuflen = fbtft_property_value(dev, "txbuflen");
+	pdata->startbyte = fbtft_property_value(dev, "startbyte");
+	device_property_read_string(dev, "gamma", (const char **)&pdata->gamma);
+
+	if (device_property_present(dev, "led-gpios"))
+		pdata->display.backlight = 1;
+	if (device_property_present(dev, "init"))
+		pdata->display.fbtftops.init_display =
+			fbtft_init_display_from_property;
+
+	pdata->display.fbtftops.request_gpios = fbtft_request_gpios;
+
+	return pdata;
+}
+
+/**
+ * fbtft_probe_common() - Generic device probe() helper function
+ * @display: Display properties
+ * @sdev: SPI device
+ * @pdev: Platform device
+ *
+ * Allocates, initializes and registers a framebuffer
+ *
+ * Either @sdev or @pdev should be NULL
+ *
+ * Return: 0 if successful, negative if error
+ */
+int fbtft_probe_common(struct fbtft_display *display,
+		       struct spi_device *sdev,
+		       struct platform_device *pdev)
+{
+	struct device *dev;
+	struct fb_info *info;
+	struct fbtft_par *par;
+	struct fbtft_platform_data *pdata;
+	int ret;
+
+	if (sdev)
+		dev = &sdev->dev;
+	else
+		dev = &pdev->dev;
+
+	if (unlikely(display->debug & DEBUG_DRIVER_INIT_FUNCTIONS))
+		dev_info(dev, "%s()\n", __func__);
+
+	pdata = dev->platform_data;
+	if (!pdata) {
+		pdata = fbtft_properties_read(dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+	}
+
+	info = fbtft_framebuffer_alloc(display, dev, pdata);
+	if (!info)
+		return -ENOMEM;
+
+	par = info->par;
+	par->spi = sdev;
+	par->pdev = pdev;
+
+	if (display->buswidth == 0) {
+		dev_err(dev, "buswidth is not set\n");
+		return -EINVAL;
+	}
+
+	/* write register functions */
+	if (display->regwidth == 8 && display->buswidth == 8)
+		par->fbtftops.write_register = fbtft_write_reg8_bus8;
+	else if (display->regwidth == 8 && display->buswidth == 9 && par->spi)
+		par->fbtftops.write_register = fbtft_write_reg8_bus9;
+	else if (display->regwidth == 16 && display->buswidth == 8)
+		par->fbtftops.write_register = fbtft_write_reg16_bus8;
+	else if (display->regwidth == 16 && display->buswidth == 16)
+		par->fbtftops.write_register = fbtft_write_reg16_bus16;
+	else
+		dev_warn(dev,
+			 "no default functions for regwidth=%d and buswidth=%d\n",
+			 display->regwidth, display->buswidth);
+
+	/* write_vmem() functions */
+	if (display->buswidth == 8)
+		par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
+	else if (display->buswidth == 9)
+		par->fbtftops.write_vmem = fbtft_write_vmem16_bus9;
+	else if (display->buswidth == 16)
+		par->fbtftops.write_vmem = fbtft_write_vmem16_bus16;
+
+	/* GPIO write() functions */
+	if (par->pdev) {
+		if (display->buswidth == 8)
+			par->fbtftops.write = fbtft_write_gpio8_wr;
+		else if (display->buswidth == 16)
+			par->fbtftops.write = fbtft_write_gpio16_wr;
+	}
+
+	/* 9-bit SPI setup */
+	if (par->spi && display->buswidth == 9) {
+		if (par->spi->master->bits_per_word_mask & SPI_BPW_MASK(9)) {
+			par->spi->bits_per_word = 9;
+		} else {
+			dev_warn(&par->spi->dev,
+				 "9-bit SPI not available, emulating using 8-bit.\n");
+			/* allocate buffer with room for dc bits */
+			par->extra = devm_kzalloc(par->info->device,
+						  par->txbuf.len +
+						  (par->txbuf.len / 8) + 8,
+						  GFP_KERNEL);
+			if (!par->extra) {
+				ret = -ENOMEM;
+				goto out_release;
+			}
+			par->fbtftops.write = fbtft_write_spi_emulate_9;
+		}
+	}
+
+	if (!par->fbtftops.verify_gpios)
+		par->fbtftops.verify_gpios = fbtft_verify_gpios;
+
+	/* make sure we still use the driver provided functions */
+	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
+
+	/* use init_sequence if provided */
+	if (par->init_sequence)
+		par->fbtftops.init_display = fbtft_init_display;
+
+	/* use platform_data provided functions above all */
+	fbtft_merge_fbtftops(&par->fbtftops, &pdata->display.fbtftops);
+
+	ret = fbtft_register_framebuffer(info);
+	if (ret < 0)
+		goto out_release;
+
+	return 0;
+
+out_release:
+	fbtft_framebuffer_release(info);
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_probe_common);
+
+/**
+ * fbtft_remove_common() - Generic device remove() helper function
+ * @dev: Device
+ * @info: Framebuffer
+ *
+ * Unregisters and releases the framebuffer
+ */
+void fbtft_remove_common(struct device *dev, struct fb_info *info)
+{
+	struct fbtft_par *par;
+
+	par = info->par;
+	if (par)
+		fbtft_par_dbg(DEBUG_DRIVER_INIT_FUNCTIONS, par,
+			      "%s()\n", __func__);
+	fbtft_unregister_framebuffer(info);
+	fbtft_framebuffer_release(info);
+}
+EXPORT_SYMBOL(fbtft_remove_common);
+
+MODULE_LICENSE("GPL");