staging: fbtft: core support

This commit adds the core fbtft framework from
https://github.com/notro/fbtft.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NNoralf Tronnes <notro@tronnes.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/Kconfig

@@ -106,4 +106,6 @@ source "drivers/staging/unisys/Kconfig"
 
 source "drivers/staging/clocking-wizard/Kconfig"
 
+source "drivers/staging/fbtft/Kconfig"
+
 endif # STAGING

drivers/staging/Makefile

@@ -45,3 +45,4 @@ obj-$(CONFIG_GS_FPGABOOT)	+= gs_fpgaboot/
 obj-$(CONFIG_CRYPTO_SKEIN)	+= skein/
 obj-$(CONFIG_UNISYSSPAR)	+= unisys/
 obj-$(CONFIG_COMMON_CLK_XLNX_CLKWZRD)	+= clocking-wizard/
+obj-$(CONFIG_FB_TFT)		+= fbtft/

drivers/staging/fbtft/Kconfig

+menuconfig FB_TFT
+	tristate "Support for small TFT LCD display modules"
+	depends on FB && SPI && GPIOLIB
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_SYS_FOPS
+	select FB_DEFERRED_IO
+	select FB_BACKLIGHT

drivers/staging/fbtft/Makefile

+# Core module
+obj-$(CONFIG_FB_TFT)             += fbtft.o
+fbtft-y                          += fbtft-core.o fbtft-sysfs.o fbtft-bus.o fbtft-io.o

drivers/staging/fbtft/README

+  FBTFT
+=========
+
+Linux Framebuffer drivers for small TFT LCD display modules.
+The module 'fbtft' makes writing drivers for some of these displays very easy.
+
+Development is done on a Raspberry Pi running the Raspbian "wheezy" distribution.
+
+INSTALLATION
+  Download kernel sources
+
+  From Linux 3.15  
+    cd drivers/video/fbdev/fbtft
+    git clone https://github.com/notro/fbtft.git
+    
+    Add to drivers/video/fbdev/Kconfig:   source "drivers/video/fbdev/fbtft/Kconfig"
+    Add to drivers/video/fbdev/Makefile:  obj-y += fbtft/
+  
+  Before Linux 3.15  
+    cd drivers/video
+    git clone https://github.com/notro/fbtft.git
+    
+    Add to drivers/video/Kconfig:   source "drivers/video/fbtft/Kconfig"
+    Add to drivers/video/Makefile:  obj-y += fbtft/
+  
+  Enable driver(s) in menuconfig and build the kernel
+
+
+See wiki for more information: https://github.com/notro/fbtft/wiki
+
+
+Source: https://github.com/notro/fbtft/

drivers/staging/fbtft/fbtft-bus.c

+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include "fbtft.h"
+
+
+
+
+/*****************************************************************************
+ *
+ *   void (*write_reg)(struct fbtft_par *par, int len, ...);
+ *
+ *****************************************************************************/
+
+#define define_fbtft_write_reg(func, type, modifier)                          \
+void func(struct fbtft_par *par, int len, ...)                                \
+{                                                                             \
+	va_list args;                                                         \
+	int i, ret;                                                           \
+	int offset = 0;                                                       \
+	type *buf = (type *)par->buf;                                         \
+									      \
+	if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {                    \
+		va_start(args, len);                                          \
+		for (i = 0; i < len; i++) {                                   \
+			buf[i] = (type)va_arg(args, unsigned int);            \
+		}                                                             \
+		va_end(args);                                                 \
+		fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device, type, buf, len, "%s: ", __func__);   \
+	}                                                                     \
+									      \
+	va_start(args, len);                                                  \
+									      \
+	if (par->startbyte) {                                                 \
+		*(u8 *)par->buf = par->startbyte;                             \
+		buf = (type *)(par->buf + 1);                                 \
+		offset = 1;                                                   \
+	}                                                                     \
+									      \
+	*buf = modifier((type)va_arg(args, unsigned int));                    \
+	if (par->gpio.dc != -1)                                               \
+		gpio_set_value(par->gpio.dc, 0);                              \
+	ret = par->fbtftops.write(par, par->buf, sizeof(type)+offset);        \
+	if (ret < 0) {                                                        \
+		va_end(args);                                                 \
+		dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret); \
+		return;                                                       \
+	}                                                                     \
+	len--;                                                                \
+									      \
+	if (par->startbyte)                                                   \
+		*(u8 *)par->buf = par->startbyte | 0x2;                       \
+									      \
+	if (len) {                                                            \
+		i = len;                                                      \
+		while (i--) {                                                 \
+			*buf++ = modifier((type)va_arg(args, unsigned int));  \
+		}                                                             \
+		if (par->gpio.dc != -1)                                       \
+			gpio_set_value(par->gpio.dc, 1);                      \
+		ret = par->fbtftops.write(par, par->buf, len * (sizeof(type)+offset)); \
+		if (ret < 0) {                                                \
+			va_end(args);                                         \
+			dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret); \
+			return;                                               \
+		}                                                             \
+	}                                                                     \
+	va_end(args);                                                         \
+}                                                                             \
+EXPORT_SYMBOL(func);
+
+define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, )
+define_fbtft_write_reg(fbtft_write_reg16_bus8, u16, cpu_to_be16)
+define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, )
+
+void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...)
+{
+	va_list args;
+	int i, ret;
+	int pad = 0;
+	u16 *buf = (u16 *)par->buf;
+
+	if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
+		va_start(args, len);
+		for (i = 0; i < len; i++)
+			*(((u8 *)buf) + i) = (u8)va_arg(args, unsigned int);
+		va_end(args);
+		fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
+			par->info->device, u8, buf, len, "%s: ", __func__);
+	}
+	if (len <= 0)
+		return;
+
+	if (par->spi && (par->spi->bits_per_word == 8)) {
+		/* we're emulating 9-bit, pad start of buffer with no-ops
+		   (assuming here that zero is a no-op) */
+		pad = (len % 4) ? 4 - (len % 4) : 0;
+		for (i = 0; i < pad; i++)
+			*buf++ = 0x000;
+	}
+
+	va_start(args, len);
+	*buf++ = (u8)va_arg(args, unsigned int);
+	i = len - 1;
+	while (i--) {
+		*buf = (u8)va_arg(args, unsigned int);
+		*buf++ |= 0x100; /* dc=1 */
+	}
+	va_end(args);
+	ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
+	if (ret < 0) {
+		dev_err(par->info->device,
+			"%s: write() failed and returned %d\n", __func__, ret);
+		return;
+	}
+}
+EXPORT_SYMBOL(fbtft_write_reg8_bus9);
+
+
+
+
+/*****************************************************************************
+ *
+ *   int (*write_vmem)(struct fbtft_par *par);
+ *
+ *****************************************************************************/
+
+/* 16 bit pixel over 8-bit databus */
+int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u16 *vmem16;
+	u16 *txbuf16 = (u16 *)par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int ret = 0;
+	size_t startbyte_size = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		__func__, offset, len);
+
+	remain = len / 2;
+	vmem16 = (u16 *)(par->info->screen_base + offset);
+
+	if (par->gpio.dc != -1)
+		gpio_set_value(par->gpio.dc, 1);
+
+	/* non buffered write */
+	if (!par->txbuf.buf)
+		return par->fbtftops.write(par, vmem16, len);
+
+	/* buffered write */
+	tx_array_size = par->txbuf.len / 2;
+
+	if (par->startbyte) {
+		txbuf16 = (u16 *)(par->txbuf.buf + 1);
+		tx_array_size -= 2;
+		*(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
+		startbyte_size = 1;
+	}
+
+	while (remain) {
+		to_copy = remain > tx_array_size ? tx_array_size : remain;
+		dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
+						to_copy, remain - to_copy);
+
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i] = cpu_to_be16(vmem16[i]);
+
+		vmem16 = vmem16 + to_copy;
+		ret = par->fbtftops.write(par, par->txbuf.buf,
+						startbyte_size + to_copy * 2);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
+
+/* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
+int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u8 *vmem8;
+	u16 *txbuf16 = par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int ret = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		__func__, offset, len);
+
+	if (!par->txbuf.buf) {
+		dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
+		return -1;
+	}
+
+	remain = len;
+	vmem8 = par->info->screen_base + offset;
+
+	tx_array_size = par->txbuf.len / 2;
+
+	while (remain) {
+		to_copy = remain > tx_array_size ? tx_array_size : remain;
+		dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
+						to_copy, remain - to_copy);
+
+#ifdef __LITTLE_ENDIAN
+		for (i = 0; i < to_copy; i += 2) {
+			txbuf16[i]   = 0x0100 | vmem8[i+1];
+			txbuf16[i+1] = 0x0100 | vmem8[i];
+		}
+#else
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i]   = 0x0100 | vmem8[i];
+#endif
+		vmem8 = vmem8 + to_copy;
+		ret = par->fbtftops.write(par, par->txbuf.buf, to_copy*2);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
+
+int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+	dev_err(par->info->device, "%s: function not implemented\n", __func__);
+	return -1;
+}
+EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
+
+/* 16 bit pixel over 16-bit databus */
+int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u16 *vmem16;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		__func__, offset, len);
+
+	vmem16 = (u16 *)(par->info->screen_base + offset);
+
+	if (par->gpio.dc != -1)
+		gpio_set_value(par->gpio.dc, 1);
+
+	/* no need for buffered write with 16-bit bus */
+	return par->fbtftops.write(par, vmem16, len);
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus16);

drivers/staging/fbtft/fbtft-core.c

+/*
+ * Copyright (C) 2013 Noralf Tronnes
+ *
+ * This driver is inspired by:
+ *   st7735fb.c, Copyright (C) 2011, Matt Porter
+ *   broadsheetfb.c, Copyright (C) 2008, Jaya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#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.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/spinlock.h>
+#include <linux/dma-mapping.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+
+#include "fbtft.h"
+
+extern void fbtft_sysfs_init(struct fbtft_par *par);
+extern void fbtft_sysfs_exit(struct fbtft_par *par);
+extern void fbtft_expand_debug_value(unsigned long *debug);
+extern int fbtft_gamma_parse_str(struct fbtft_par *par, unsigned long *curves,
+						const char *str, int size);
+
+static unsigned long debug;
+module_param(debug, ulong , 0);
+MODULE_PARM_DESC(debug, "override device debug level");
+
+static bool dma = true;
+module_param(dma, bool, 0);
+MODULE_PARM_DESC(dma, "Use DMA buffer");
+
+
+void fbtft_dbg_hex(const struct device *dev, int groupsize,
+			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);
+
+unsigned long fbtft_request_gpios_match(struct fbtft_par *par,
+					const struct fbtft_gpio *gpio)
+{
+	int ret;
+	long val;
+
+	fbtft_par_dbg(DEBUG_REQUEST_GPIOS_MATCH, par, "%s('%s')\n",
+		__func__, gpio->name);
+
+	if (strcasecmp(gpio->name, "reset") == 0) {
+		par->gpio.reset = gpio->gpio;
+		return GPIOF_OUT_INIT_HIGH;
+	} else if (strcasecmp(gpio->name, "dc") == 0) {
+		par->gpio.dc = gpio->gpio;
+		return GPIOF_OUT_INIT_LOW;
+	} else if (strcasecmp(gpio->name, "cs") == 0) {
+		par->gpio.cs = gpio->gpio;
+		return GPIOF_OUT_INIT_HIGH;
+	} else if (strcasecmp(gpio->name, "wr") == 0) {
+		par->gpio.wr = gpio->gpio;
+		return GPIOF_OUT_INIT_HIGH;
+	} else if (strcasecmp(gpio->name, "rd") == 0) {
+		par->gpio.rd = gpio->gpio;
+		return GPIOF_OUT_INIT_HIGH;
+	} else if (strcasecmp(gpio->name, "latch") == 0) {
+		par->gpio.latch = gpio->gpio;
+		return GPIOF_OUT_INIT_LOW;
+	} else if (gpio->name[0] == 'd' && gpio->name[1] == 'b') {
+		ret = kstrtol(&gpio->name[2], 10, &val);
+		if (ret == 0 && val < 16) {
+			par->gpio.db[val] = gpio->gpio;
+			return GPIOF_OUT_INIT_LOW;
+		}
+	} else if (strcasecmp(gpio->name, "led") == 0) {
+		par->gpio.led[0] = gpio->gpio;
+		return GPIOF_OUT_INIT_LOW;
+	} else if (strcasecmp(gpio->name, "led_") == 0) {
+		par->gpio.led[0] = gpio->gpio;
+		return GPIOF_OUT_INIT_HIGH;
+	}
+
+	return FBTFT_GPIO_NO_MATCH;
+}
+
+int fbtft_request_gpios(struct fbtft_par *par)
+{
+	struct fbtft_platform_data *pdata = par->pdata;
+	const struct fbtft_gpio *gpio;
+	unsigned long flags;
+	int ret;
+
+	if (pdata && pdata->gpios) {
+		gpio = pdata->gpios;
+		while (gpio->name[0]) {
+			flags = FBTFT_GPIO_NO_MATCH;
+			/* if driver provides match function, try it first,
+			   if no match use our own */
+			if (par->fbtftops.request_gpios_match)
+				flags = par->fbtftops.request_gpios_match(par, gpio);
+			if (flags == FBTFT_GPIO_NO_MATCH)
+				flags = fbtft_request_gpios_match(par, gpio);
+			if (flags != FBTFT_GPIO_NO_MATCH) {
+				ret = devm_gpio_request_one(par->info->device,
+						gpio->gpio, flags,
+						par->info->device->driver->name);
+				if (ret < 0) {
+					dev_err(par->info->device,
+						"%s: gpio_request_one('%s'=%d) failed with %d\n",
+						__func__, gpio->name,
+						gpio->gpio, ret);
+					return ret;
+				}
+				fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par,
+					"%s: '%s' = GPIO%d\n",
+					__func__, gpio->name, gpio->gpio);
+			}
+			gpio++;
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static int fbtft_request_one_gpio(struct fbtft_par *par,
+				  const char *name, int index, int *gpiop)
+{
+	struct device *dev = par->info->device;
+	struct device_node *node = dev->of_node;
+	int gpio, flags, ret = 0;
+	enum of_gpio_flags of_flags;
+
+	if (of_find_property(node, name, NULL)) {
+		gpio = of_get_named_gpio_flags(node, name, index, &of_flags);
+		if (gpio == -ENOENT)
+			return 0;
+		if (gpio == -EPROBE_DEFER)
+			return gpio;
+		if (gpio < 0) {
+			dev_err(dev,
+				"failed to get '%s' from DT\n", name);
+			return gpio;
+		}
+
+		/* active low translates to initially low */
+		flags = (of_flags & OF_GPIO_ACTIVE_LOW) ? GPIOF_OUT_INIT_LOW :
+							GPIOF_OUT_INIT_HIGH;
+		ret = devm_gpio_request_one(dev, gpio, flags,
+						dev->driver->name);
+		if (ret) {
+			dev_err(dev,
+				"gpio_request_one('%s'=%d) failed with %d\n",
+				name, gpio, ret);
+			return ret;
+		}
+		if (gpiop)
+			*gpiop = gpio;
+		fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' = GPIO%d\n",
+							__func__, name, gpio);
+	}
+
+	return ret;
+}
+
+static int fbtft_request_gpios_dt(struct fbtft_par *par)
+{
+	int i;
+	int ret;
+
+	if (!par->info->device->of_node)
+		return -EINVAL;
+
+	ret = fbtft_request_one_gpio(par, "reset-gpios", 0, &par->gpio.reset);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "dc-gpios", 0, &par->gpio.dc);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "rd-gpios", 0, &par->gpio.rd);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "wr-gpios", 0, &par->gpio.wr);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "cs-gpios", 0, &par->gpio.cs);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "latch-gpios", 0, &par->gpio.latch);
+	if (ret)
+		return ret;
+	for (i = 0; i < 16; i++) {
+		ret = fbtft_request_one_gpio(par, "db-gpios", i,
+						&par->gpio.db[i]);
+		if (ret)
+			return ret;
+		ret = fbtft_request_one_gpio(par, "led-gpios", i,
+						&par->gpio.led[i]);
+		if (ret)
+			return ret;
+		ret = fbtft_request_one_gpio(par, "aux-gpios", i,
+						&par->gpio.aux[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_FB_BACKLIGHT
+int fbtft_backlight_update_status(struct backlight_device *bd)
+{
+	struct fbtft_par *par = bl_get_data(bd);
+	bool polarity = !!(bd->props.state & BL_CORE_DRIVER1);
+
+	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 ((bd->props.power == FB_BLANK_UNBLANK) && (bd->props.fb_blank == FB_BLANK_UNBLANK))
+		gpio_set_value(par->gpio.led[0], polarity);
+	else
+		gpio_set_value(par->gpio.led[0], !polarity);
+
+	return 0;
+}
+
+int fbtft_backlight_get_brightness(struct backlight_device *bd)
+{
+	return bd->props.brightness;
+}
+
+void fbtft_unregister_backlight(struct fbtft_par *par)
+{
+	const struct backlight_ops *bl_ops;
+
+	fbtft_par_dbg(DEBUG_BACKLIGHT, par, "%s()\n", __func__);
+
+	if (par->info->bl_dev) {
+		par->info->bl_dev->props.power = FB_BLANK_POWERDOWN;
+		backlight_update_status(par->info->bl_dev);
+		bl_ops = par->info->bl_dev->ops;
+		backlight_device_unregister(par->info->bl_dev);
+		par->info->bl_dev = NULL;
+	}
+}
+
+void fbtft_register_backlight(struct fbtft_par *par)
+{
+	struct backlight_device *bd;
+	struct backlight_properties bl_props = { 0, };
+	struct backlight_ops *bl_ops;
+
+	fbtft_par_dbg(DEBUG_BACKLIGHT, par, "%s()\n", __func__);
+
+	if (par->gpio.led[0] == -1) {
+		fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+			"%s(): led pin not set, exiting.\n", __func__);
+		return;
+	}
+
+	bl_ops = devm_kzalloc(par->info->device, sizeof(struct backlight_ops),
+				GFP_KERNEL);
+	if (!bl_ops) {
+		dev_err(par->info->device,
+			"%s: could not allocate memeory for backlight operations.\n",
+			__func__);
+		return;
+	}
+
+	bl_ops->get_brightness = fbtft_backlight_get_brightness;
+	bl_ops->update_status = fbtft_backlight_update_status;
+	bl_props.type = BACKLIGHT_RAW;
+	/* Assume backlight is off, get polarity from current state of pin */
+	bl_props.power = FB_BLANK_POWERDOWN;
+	if (!gpio_get_value(par->gpio.led[0]))
+		bl_props.state |= BL_CORE_DRIVER1;
+
+	bd = backlight_device_register(dev_driver_string(par->info->device),
+				par->info->device, par, 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;
+}
+#else
+void fbtft_register_backlight(struct fbtft_par *par) { };
+void fbtft_unregister_backlight(struct fbtft_par *par) { };
+#endif
+EXPORT_SYMBOL(fbtft_register_backlight);
+EXPORT_SYMBOL(fbtft_unregister_backlight);
+
+void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
+{
+	fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par,
+		"%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye);
+
+	/* Column address set */
+	write_reg(par, 0x2A,
+		(xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
+
+	/* Row adress set */
+	write_reg(par, 0x2B,
+		(ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
+
+	/* Memory write */
+	write_reg(par, 0x2C);
+}
+
+
+void fbtft_reset(struct fbtft_par *par)
+{
+	if (par->gpio.reset == -1)
+		return;
+	fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
+	gpio_set_value(par->gpio.reset, 0);
+	udelay(20);
+	gpio_set_value(par->gpio.reset, 1);
+	mdelay(120);
+}
+
+
+void fbtft_update_display(struct fbtft_par *par, unsigned start_line, unsigned end_line)
+{
+	size_t offset, len;
+	struct timespec ts_start, ts_end, ts_fps, ts_duration;
+	long fps_ms, fps_us, duration_ms, duration_us;
+	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)) {
+			getnstimeofday(&ts_start);
+			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)) {
+		getnstimeofday(&ts_end);
+		if (par->update_time.tv_nsec == 0 && par->update_time.tv_sec == 0) {
+			par->update_time.tv_sec = ts_start.tv_sec;
+			par->update_time.tv_nsec = ts_start.tv_nsec;
+		}
+		ts_fps = timespec_sub(ts_start, par->update_time);
+		par->update_time.tv_sec = ts_start.tv_sec;
+		par->update_time.tv_nsec = ts_start.tv_nsec;
+		fps_ms = (ts_fps.tv_sec * 1000) + ((ts_fps.tv_nsec / 1000000) % 1000);
+		fps_us = (ts_fps.tv_nsec / 1000) % 1000;
+		fps = fps_ms * 1000 + fps_us;
+		fps = fps ? 1000000 / fps : 0;
+
+		ts_duration = timespec_sub(ts_end, ts_start);
+		duration_ms = (ts_duration.tv_sec * 1000) + ((ts_duration.tv_nsec / 1000000) % 1000);
+		duration_us = (ts_duration.tv_nsec / 1000) % 1000;
+		throughput = duration_ms * 1000 + duration_us;
+		throughput = throughput ? (len * 1000) / throughput : 0;
+		throughput = throughput * 1000 / 1024;
+
+		dev_info(par->info->device,
+			"Display update: %ld kB/s (%ld.%.3ld ms), fps=%ld (%ld.%.3ld ms)\n",
+			throughput, duration_ms, duration_us,
+			fps, fps_ms, fps_us);
+		par->first_update_done = true;
+	}
+}
+
+
+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 - 1;
+	}
+
+	/* 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);
+}
+
+void fbtft_deferred_io(struct fb_info *info, struct list_head *pagelist)
+{
+	struct fbtft_par *par = info->par;
+	unsigned dirty_lines_start, dirty_lines_end;
+	struct page *page;
+	unsigned long index;
+	unsigned 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(page, pagelist, lru) {
+		count++;
+		index = page->index << PAGE_SHIFT;
+		y_low = index / info->fix.line_length;
+		y_high = (index + PAGE_SIZE - 1) / info->fix.line_length;
+		fbtft_dev_dbg(DEBUG_DEFERRED_IO, par, info->device,
+			"page->index=%lu y_low=%d y_high=%d\n",
+			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);
+}
+
+
+void fbtft_fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	struct fbtft_par *par = info->par;
+
+	fbtft_dev_dbg(DEBUG_FB_FILLRECT, par, 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);
+}
+
+void fbtft_fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+	struct fbtft_par *par = info->par;
+
+	fbtft_dev_dbg(DEBUG_FB_COPYAREA, par, 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);
+}
+
+void fbtft_fb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	struct fbtft_par *par = info->par;
+
+	fbtft_dev_dbg(DEBUG_FB_IMAGEBLIT, par, 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);
+}
+
+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;
+
+	fbtft_dev_dbg(DEBUG_FB_WRITE, par, 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 */
+unsigned int chan_to_field(unsigned chan, struct fb_bitfield *bf)
+{
+	chan &= 0xffff;
+	chan >>= 16 - bf->length;
+	return chan << bf->offset;
+}
+
+int fbtft_fb_setcolreg(unsigned regno,
+			       unsigned red, unsigned green, unsigned blue,
+			       unsigned transp, struct fb_info *info)
+{
+	struct fbtft_par *par = info->par;
+	unsigned val;
+	int ret = 1;
+
+	fbtft_dev_dbg(DEBUG_FB_SETCOLREG, par, 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;
+}
+
+int fbtft_fb_blank(int blank, struct fb_info *info)
+{
+	struct fbtft_par *par = info->par;
+	int ret = -EINVAL;
+
+	fbtft_dev_dbg(DEBUG_FB_BLANK, par, 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;
+}
+
+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
+ *
+ * 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 fb_info *info;
+	struct fbtft_par *par;
+	struct fb_ops *fbops = NULL;
+	struct fb_deferred_io *fbdefio = NULL;
+	struct fbtft_platform_data *pdata = dev->platform_data;
+	u8 *vmem = NULL;
+	void *txbuf = NULL;
+	void *buf = NULL;
+	unsigned width;
+	unsigned height;
+	int txbuflen = display->txbuflen;
+	unsigned bpp = display->bpp;
+	unsigned fps = display->fps;
+	int vmem_size, i;
+	int *init_sequence = display->init_sequence;
+	char *gamma = display->gamma;
+	unsigned long *gamma_curves = NULL;
+
+	/* sanity check */
+	if (display->gamma_num * display->gamma_len > FBTFT_GAMMA_MAX_VALUES_TOTAL) {
+		dev_err(dev,
+			"%s: FBTFT_GAMMA_MAX_VALUES_TOTAL=%d is exceeded\n",
+			__func__, 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_kzalloc(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_base = (u8 __force __iomem *)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;
+
+	fbdefio->delay =           HZ/fps;
+	fbdefio->deferred_io =     fbtft_deferred_io;
+	fb_deferred_io_init(info);
+
+	strncpy(info->fix.id, dev->driver->name, 16);
+	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;
+
+	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 = dev->platform_data;
+	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 alloc_fail;
+	}
+
+	/* Transmit buffer */
+	if (txbuflen == -1)
+		txbuflen = vmem_size + 2; /* add in case startbyte is used */
+
+#ifdef __LITTLE_ENDIAN
+	if ((!txbuflen) && (bpp > 8))
+		txbuflen = PAGE_SIZE; /* need buffer for byteswapping */
+#endif
+
+	if (txbuflen > 0) {
+		if (dma) {
+			dev->coherent_dma_mask = ~0;
+			txbuf = dmam_alloc_coherent(dev, txbuflen, &par->txbuf.dma, GFP_DMA);
+		} else {
+			txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
+		}
+		if (!txbuf)
+			goto alloc_fail;
+		par->txbuf.buf = txbuf;
+		par->txbuf.len = txbuflen;
+	}
+
+	/* Initialize gpios to disabled */
+	par->gpio.reset = -1;
+	par->gpio.dc = -1;
+	par->gpio.rd = -1;
+	par->gpio.wr = -1;
+	par->gpio.cs = -1;
+	par->gpio.latch = -1;
+	for (i = 0; i < 16; i++) {
+		par->gpio.db[i] = -1;
+		par->gpio.led[i] = -1;
+		par->gpio.aux[i] = -1;
+	}
+
+	/* 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;
+	par->fbtftops.request_gpios = fbtft_request_gpios;
+	if (display->backlight)
+		par->fbtftops.register_backlight = fbtft_register_backlight;
+
+	/* use driver provided functions */
+	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
+
+	return 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_base);
+	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)
+		sprintf(text1, ", %d KiB %sbuffer memory",
+			par->txbuf.len >> 10, par->txbuf.dma ? "DMA " : "");
+	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);
+
+#ifdef CONFIG_FB_BACKLIGHT
+	/* 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);
+	}
+#endif
+
+	return 0;
+
+reg_fail:
+	if (par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight(par);
+	if (spi)
+		spi_set_drvdata(spi, NULL);
+	if (par->pdev)
+		platform_set_drvdata(par->pdev, NULL);
+
+	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;
+	struct spi_device *spi = par->spi;
+	int ret;
+
+	if (spi)
+		spi_set_drvdata(spi, NULL);
+	if (par->pdev)
+		platform_set_drvdata(par->pdev, NULL);
+	if (par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight(par);
+	fbtft_sysfs_exit(par);
+	ret = unregister_framebuffer(fb_info);
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_unregister_framebuffer);
+
+#ifdef CONFIG_OF
+/**
+ * fbtft_init_display_dt() - Device Tree init_display() function
+ * @par: Driver data
+ *
+ * Return: 0 if successful, negative if error
+ */
+static int fbtft_init_display_dt(struct fbtft_par *par)
+{
+	struct device_node *node = par->info->device->of_node;
+	struct property *prop;
+	const __be32 *p;
+	u32 val;
+	int buf[64], i, j;
+	char msg[128];
+	char str[16];
+
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	if (!node)
+		return -EINVAL;
+
+	prop = of_find_property(node, "init", NULL);
+	p = of_prop_next_u32(prop, NULL, &val);
+	if (!p)
+		return -EINVAL;
+	while (p) {
+		if (val & FBTFT_OF_INIT_CMD) {
+			val &= 0xFFFF;
+			i = 0;
+			while (p && !(val & 0xFFFF0000)) {
+				if (i > 63) {
+					dev_err(par->info->device,
+					"%s: Maximum register values exceeded\n",
+					__func__);
+					return -EINVAL;
+				}
+				buf[i++] = val;
+				p = of_prop_next_u32(prop, p, &val);
+			}
+			/* make debug message */
+			msg[0] = '\0';
+			for (j = 0; j < i; j++) {
+				snprintf(str, 128, " %02X", buf[j]);
+				strcat(msg, str);
+			}
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				"init: write_register:%s\n", msg);
+
+			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);
+			p = of_prop_next_u32(prop, p, &val);
+		} else {
+			dev_err(par->info->device, "illegal init value 0x%X\n",
+									val);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+#endif
+
+/**
+ * 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];
+	char msg[128];
+	char str[16];
+	int i = 0;
+	int j;
+
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	/* 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);
+	if (par->gpio.cs != -1)
+		gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
+
+	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 */
+			strcpy(msg, "");
+			j = i + 1;
+			while (par->init_sequence[j] >= 0) {
+				sprintf(str, "0x%02X ", par->init_sequence[j]);
+				strcat(msg, str);
+				j++;
+			}
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				"init: write(0x%02X) %s\n",
+				par->init_sequence[i], msg);
+
+			/* 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
+ */
+int fbtft_verify_gpios(struct fbtft_par *par)
+{
+	struct fbtft_platform_data *pdata;
+	int i;
+
+	fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
+
+	pdata = par->info->device->platform_data;
+	if (pdata->display.buswidth != 9 && par->startbyte == 0 && \
+							par->gpio.dc < 0) {
+		dev_err(par->info->device,
+			"Missing info about 'dc' gpio. Aborting.\n");
+		return -EINVAL;
+	}
+
+	if (!par->pdev)
+		return 0;
+
+	if (par->gpio.wr < 0) {
+		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] < 0) {
+			dev_err(par->info->device,
+				"Missing 'db%02d' gpio. Aborting.\n", i);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+/* returns 0 if the property is not present */
+static u32 fbtft_of_value(struct device_node *node, const char *propname)
+{
+	int ret;
+	u32 val = 0;
+
+	ret = of_property_read_u32(node, propname, &val);
+	if (ret == 0)
+		pr_info("%s: %s = %u\n", __func__, propname, val);
+
+	return val;
+}
+
+static struct fbtft_platform_data *fbtft_probe_dt(struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	struct fbtft_platform_data *pdata;
+
+	if (!node) {
+		dev_err(dev, "Missing platform data or DT\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	pdata->display.width = fbtft_of_value(node, "width");
+	pdata->display.height = fbtft_of_value(node, "height");
+	pdata->display.regwidth = fbtft_of_value(node, "regwidth");
+	pdata->display.buswidth = fbtft_of_value(node, "buswidth");
+	pdata->display.backlight = fbtft_of_value(node, "backlight");
+	pdata->display.bpp = fbtft_of_value(node, "bpp");
+	pdata->display.debug = fbtft_of_value(node, "debug");
+	pdata->rotate = fbtft_of_value(node, "rotate");
+	pdata->bgr = of_property_read_bool(node, "bgr");
+	pdata->fps = fbtft_of_value(node, "fps");
+	pdata->txbuflen = fbtft_of_value(node, "txbuflen");
+	pdata->startbyte = fbtft_of_value(node, "startbyte");
+	of_property_read_string(node, "gamma", (const char **)&pdata->gamma);
+
+	if (of_find_property(node, "led-gpios", NULL))
+		pdata->display.backlight = 1;
+	if (of_find_property(node, "init", NULL))
+		pdata->display.fbtftops.init_display = fbtft_init_display_dt;
+	pdata->display.fbtftops.request_gpios = fbtft_request_gpios_dt;
+
+	return pdata;
+}
+#else
+static struct fbtft_platform_data *fbtft_probe_dt(struct device *dev)
+{
+	dev_err(dev, "Missing platform data\n");
+	return ERR_PTR(-EINVAL);
+}
+#endif
+
+/**
+ * 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_probe_dt(dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+		dev->platform_data = pdata;
+	}
+
+	info = fbtft_framebuffer_alloc(display, dev);
+	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) {
+		par->spi->bits_per_word = 9;
+		ret = par->spi->master->setup(par->spi);
+		if (ret) {
+			dev_warn(&par->spi->dev,
+				"9-bit SPI not available, emulating using 8-bit.\n");
+			par->spi->bits_per_word = 8;
+			ret = par->spi->master->setup(par->spi);
+			if (ret)
+				goto out_release;
+			/* 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
+ *
+ * Return: 0 if successful, negative if error
+ */
+int fbtft_remove_common(struct device *dev, struct fb_info *info)
+{
+	struct fbtft_par *par;
+
+	if (!info)
+		return -EINVAL;
+	par = info->par;
+	if (par)
+		fbtft_par_dbg(DEBUG_DRIVER_INIT_FUNCTIONS, par,
+			"%s()\n", __func__);
+	fbtft_unregister_framebuffer(info);
+	fbtft_framebuffer_release(info);
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_remove_common);
+
+MODULE_LICENSE("GPL");

drivers/staging/fbtft/fbtft-io.c

+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#ifdef CONFIG_ARCH_BCM2708
+#include <mach/platform.h>
+#endif
+#include "fbtft.h"
+
+int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+	struct spi_transfer t = {
+		.tx_buf = buf,
+		.len = len,
+	};
+	struct spi_message m;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	if (!par->spi) {
+		dev_err(par->info->device,
+			"%s: par->spi is unexpectedly NULL\n", __func__);
+		return -1;
+	}
+
+	spi_message_init(&m);
+	if (par->txbuf.dma && buf == par->txbuf.buf) {
+		t.tx_dma = par->txbuf.dma;
+		m.is_dma_mapped = 1;
+	}
+	spi_message_add_tail(&t, &m);
+	return spi_sync(par->spi, &m);
+}
+EXPORT_SYMBOL(fbtft_write_spi);
+
+/**
+ * fbtft_write_spi_emulate_9() - write SPI emulating 9-bit
+ * @par: Driver data
+ * @buf: Buffer to write
+ * @len: Length of buffer (must be divisible by 8)
+ *
+ * When 9-bit SPI is not available, this function can be used to emulate that.
+ * par->extra must hold a transformation buffer used for transfer.
+ */
+int fbtft_write_spi_emulate_9(struct fbtft_par *par, void *buf, size_t len)
+{
+	u16 *src = buf;
+	u8 *dst = par->extra;
+	size_t size = len / 2;
+	size_t added = 0;
+	int bits, i, j;
+	u64 val, dc, tmp;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	if (!par->extra) {
+		dev_err(par->info->device, "%s: error: par->extra is NULL\n",
+			__func__);
+		return -EINVAL;
+	}
+	if ((len % 8) != 0) {
+		dev_err(par->info->device,
+			"%s: error: len=%d must be divisible by 8\n",
+			__func__, len);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < size; i += 8) {
+		tmp = 0;
+		bits = 63;
+		for (j = 0; j < 7; j++) {
+			dc = (*src & 0x0100) ? 1 : 0;
+			val = *src & 0x00FF;
+			tmp |= dc << bits;
+			bits -= 8;
+			tmp |= val << bits--;
+			src++;
+		}
+		tmp |= ((*src & 0x0100) ? 1 : 0);
+		*(u64 *)dst = cpu_to_be64(tmp);
+		dst += 8;
+		*dst++ = (u8)(*src++ & 0x00FF);
+		added++;
+	}
+
+	return spi_write(par->spi, par->extra, size + added);
+}
+EXPORT_SYMBOL(fbtft_write_spi_emulate_9);
+
+int fbtft_read_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+	int ret;
+	u8 txbuf[32] = { 0, };
+	struct spi_transfer	t = {
+			.speed_hz = 2000000,
+			.rx_buf		= buf,
+			.len		= len,
+		};
+	struct spi_message	m;
+
+	if (!par->spi) {
+		dev_err(par->info->device,
+			"%s: par->spi is unexpectedly NULL\n", __func__);
+		return -ENODEV;
+	}
+
+	if (par->startbyte) {
+		if (len > 32) {
+			dev_err(par->info->device,
+				"%s: len=%d can't be larger than 32 when using 'startbyte'\n",
+				__func__, len);
+			return -EINVAL;
+		}
+		txbuf[0] = par->startbyte | 0x3;
+		t.tx_buf = txbuf;
+		fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8,
+			txbuf, len, "%s(len=%d) txbuf => ", __func__, len);
+	}
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	ret = spi_sync(par->spi, &m);
+	fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8, buf, len,
+		"%s(len=%d) buf <= ", __func__, len);
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_read_spi);
+
+
+#ifdef CONFIG_ARCH_BCM2708
+
+/*
+ *  Raspberry Pi
+ *  -  writing directly to the registers is 40-50% faster than
+ *     optimized use of gpiolib
+ */
+
+#define GPIOSET(no, ishigh)           \
+do {                                  \
+	if (ishigh)                   \
+		set |= (1 << (no));   \
+	else                          \
+		reset |= (1 << (no)); \
+} while (0)
+
+int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+	unsigned int set = 0;
+	unsigned int reset = 0;
+	u8 data;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	while (len--) {
+		data = *(u8 *) buf;
+		buf++;
+
+		/* Set data */
+		GPIOSET(par->gpio.db[0], (data&0x01));
+		GPIOSET(par->gpio.db[1], (data&0x02));
+		GPIOSET(par->gpio.db[2], (data&0x04));
+		GPIOSET(par->gpio.db[3], (data&0x08));
+		GPIOSET(par->gpio.db[4], (data&0x10));
+		GPIOSET(par->gpio.db[5], (data&0x20));
+		GPIOSET(par->gpio.db[6], (data&0x40));
+		GPIOSET(par->gpio.db[7], (data&0x80));
+		writel(set, __io_address(GPIO_BASE+0x1C));
+		writel(reset, __io_address(GPIO_BASE+0x28));
+
+		/* Pulse /WR low */
+		writel((1<<par->gpio.wr),  __io_address(GPIO_BASE+0x28));
+		writel(0,  __io_address(GPIO_BASE+0x28)); /* used as a delay */
+		writel((1<<par->gpio.wr),  __io_address(GPIO_BASE+0x1C));
+
+		set = 0;
+		reset = 0;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio8_wr);
+
+int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+	unsigned int set = 0;
+	unsigned int reset = 0;
+	u16 data;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	while (len) {
+		len -= 2;
+		data = *(u16 *) buf;
+		buf += 2;
+
+		/* Start writing by pulling down /WR */
+		gpio_set_value(par->gpio.wr, 0);
+
+		/* Set data */
+		GPIOSET(par->gpio.db[0],  (data&0x0001));
+		GPIOSET(par->gpio.db[1],  (data&0x0002));
+		GPIOSET(par->gpio.db[2],  (data&0x0004));
+		GPIOSET(par->gpio.db[3],  (data&0x0008));
+		GPIOSET(par->gpio.db[4],  (data&0x0010));
+		GPIOSET(par->gpio.db[5],  (data&0x0020));
+		GPIOSET(par->gpio.db[6],  (data&0x0040));
+		GPIOSET(par->gpio.db[7],  (data&0x0080));
+
+		GPIOSET(par->gpio.db[8],  (data&0x0100));
+		GPIOSET(par->gpio.db[9],  (data&0x0200));
+		GPIOSET(par->gpio.db[10], (data&0x0400));
+		GPIOSET(par->gpio.db[11], (data&0x0800));
+		GPIOSET(par->gpio.db[12], (data&0x1000));
+		GPIOSET(par->gpio.db[13], (data&0x2000));
+		GPIOSET(par->gpio.db[14], (data&0x4000));
+		GPIOSET(par->gpio.db[15], (data&0x8000));
+
+		writel(set, __io_address(GPIO_BASE+0x1C));
+		writel(reset, __io_address(GPIO_BASE+0x28));
+
+		/* Pullup /WR */
+		gpio_set_value(par->gpio.wr, 1);
+
+		set = 0;
+		reset = 0;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr);
+
+int fbtft_write_gpio16_wr_latched(struct fbtft_par *par, void *buf, size_t len)
+{
+	unsigned int set = 0;
+	unsigned int reset = 0;
+	u16 data;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	while (len) {
+		len -= 2;
+		data = *(u16 *) buf;
+		buf += 2;
+
+		/* Start writing by pulling down /WR */
+		gpio_set_value(par->gpio.wr, 0);
+
+		/* Low byte */
+		GPIOSET(par->gpio.db[0],  (data&0x0001));
+		GPIOSET(par->gpio.db[1],  (data&0x0002));
+		GPIOSET(par->gpio.db[2],  (data&0x0004));
+		GPIOSET(par->gpio.db[3],  (data&0x0008));
+		GPIOSET(par->gpio.db[4],  (data&0x0010));
+		GPIOSET(par->gpio.db[5],  (data&0x0020));
+		GPIOSET(par->gpio.db[6],  (data&0x0040));
+		GPIOSET(par->gpio.db[7],  (data&0x0080));
+		writel(set, __io_address(GPIO_BASE+0x1C));
+		writel(reset, __io_address(GPIO_BASE+0x28));
+
+		/* Pulse 'latch' high */
+		gpio_set_value(par->gpio.latch, 1);
+		gpio_set_value(par->gpio.latch, 0);
+
+		/* High byte */
+		GPIOSET(par->gpio.db[0], (data&0x0100));
+		GPIOSET(par->gpio.db[1], (data&0x0200));
+		GPIOSET(par->gpio.db[2], (data&0x0400));
+		GPIOSET(par->gpio.db[3], (data&0x0800));
+		GPIOSET(par->gpio.db[4], (data&0x1000));
+		GPIOSET(par->gpio.db[5], (data&0x2000));
+		GPIOSET(par->gpio.db[6], (data&0x4000));
+		GPIOSET(par->gpio.db[7], (data&0x8000));
+		writel(set, __io_address(GPIO_BASE+0x1C));
+		writel(reset, __io_address(GPIO_BASE+0x28));
+
+		/* Pullup /WR */
+		gpio_set_value(par->gpio.wr, 1);
+
+		set = 0;
+		reset = 0;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr_latched);
+
+#undef GPIOSET
+
+#else
+
+/*
+ * Optimized use of gpiolib is twice as fast as no optimization
+ * only one driver can use the optimized version at a time
+ */
+int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+	u8 data;
+	int i;
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+	static u8 prev_data;
+#endif
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	while (len--) {
+		data = *(u8 *) buf;
+
+		/* Start writing by pulling down /WR */
+		gpio_set_value(par->gpio.wr, 0);
+
+		/* Set data */
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		if (data == prev_data) {
+			gpio_set_value(par->gpio.wr, 0); /* used as delay */
+		} else {
+			for (i = 0; i < 8; i++) {
+				if ((data & 1) != (prev_data & 1))
+					gpio_set_value(par->gpio.db[i],
+								(data & 1));
+				data >>= 1;
+				prev_data >>= 1;
+			}
+		}
+#else
+		for (i = 0; i < 8; i++) {
+			gpio_set_value(par->gpio.db[i], (data & 1));
+			data >>= 1;
+		}
+#endif
+
+		/* Pullup /WR */
+		gpio_set_value(par->gpio.wr, 1);
+
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		prev_data = *(u8 *) buf;
+#endif
+		buf++;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio8_wr);
+
+int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+	u16 data;
+	int i;
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+	static u16 prev_data;
+#endif
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	while (len) {
+		data = *(u16 *) buf;
+
+		/* Start writing by pulling down /WR */
+		gpio_set_value(par->gpio.wr, 0);
+
+		/* Set data */
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		if (data == prev_data) {
+			gpio_set_value(par->gpio.wr, 0); /* used as delay */
+		} else {
+			for (i = 0; i < 16; i++) {
+				if ((data & 1) != (prev_data & 1))
+					gpio_set_value(par->gpio.db[i],
+								(data & 1));
+				data >>= 1;
+				prev_data >>= 1;
+			}
+		}
+#else
+		for (i = 0; i < 16; i++) {
+			gpio_set_value(par->gpio.db[i], (data & 1));
+			data >>= 1;
+		}
+#endif
+
+		/* Pullup /WR */
+		gpio_set_value(par->gpio.wr, 1);
+
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		prev_data = *(u16 *) buf;
+#endif
+		buf += 2;
+		len -= 2;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr);
+
+int fbtft_write_gpio16_wr_latched(struct fbtft_par *par, void *buf, size_t len)
+{
+	dev_err(par->info->device, "%s: function not implemented\n", __func__);
+	return -1;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr_latched);
+
+#endif /* CONFIG_ARCH_BCM2708 */

drivers/staging/fbtft/fbtft-sysfs.c

+#include "fbtft.h"
+
+
+static int get_next_ulong(char **str_p, unsigned long *val, char *sep, int base)
+{
+	char *p_val;
+	int ret;
+
+	if (!str_p || !(*str_p))
+		return -EINVAL;
+
+	p_val = strsep(str_p, sep);
+
+	if (!p_val)
+		return -EINVAL;
+
+	ret = kstrtoul(p_val, base, val);
+	if (ret)
+		return -EINVAL;
+
+	return 0;
+}
+
+int fbtft_gamma_parse_str(struct fbtft_par *par, unsigned long *curves,
+						const char *str, int size)
+{
+	char *str_p, *curve_p = NULL;
+	char *tmp;
+	unsigned long val = 0;
+	int ret = 0;
+	int curve_counter, value_counter;
+
+	fbtft_par_dbg(DEBUG_SYSFS, par, "%s() str=\n", __func__);
+
+	if (!str || !curves)
+		return -EINVAL;
+
+	fbtft_par_dbg(DEBUG_SYSFS, par, "%s\n", str);
+
+	tmp = kmalloc(size+1, GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+	memcpy(tmp, str, size+1);
+
+	/* replace optional separators */
+	str_p = tmp;
+	while (*str_p) {
+		if (*str_p == ',')
+			*str_p = ' ';
+		if (*str_p == ';')
+			*str_p = '\n';
+		str_p++;
+	}
+
+	str_p = strim(tmp);
+
+	curve_counter = 0;
+	while (str_p) {
+		if (curve_counter == par->gamma.num_curves) {
+			dev_err(par->info->device, "Gamma: Too many curves\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		curve_p = strsep(&str_p, "\n");
+		value_counter = 0;
+		while (curve_p) {
+			if (value_counter == par->gamma.num_values) {
+				dev_err(par->info->device,
+					"Gamma: Too many values\n");
+				ret = -EINVAL;
+				goto out;
+			}
+			ret = get_next_ulong(&curve_p, &val, " ", 16);
+			if (ret)
+				goto out;
+			curves[curve_counter * par->gamma.num_values + value_counter] = val;
+			value_counter++;
+		}
+		if (value_counter != par->gamma.num_values) {
+			dev_err(par->info->device, "Gamma: Too few values\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		curve_counter++;
+	}
+	if (curve_counter != par->gamma.num_curves) {
+		dev_err(par->info->device, "Gamma: Too few curves\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+out:
+	kfree(tmp);
+	return ret;
+}
+
+static ssize_t
+sprintf_gamma(struct fbtft_par *par, unsigned long *curves, char *buf)
+{
+	ssize_t len = 0;
+	unsigned int i, j;
+
+	mutex_lock(&par->gamma.lock);
+	for (i = 0; i < par->gamma.num_curves; i++) {
+		for (j = 0; j < par->gamma.num_values; j++)
+			len += scnprintf(&buf[len], PAGE_SIZE,
+				"%04lx ", curves[i*par->gamma.num_values + j]);
+		buf[len-1] = '\n';
+	}
+	mutex_unlock(&par->gamma.lock);
+
+	return len;
+}
+
+static ssize_t store_gamma_curve(struct device *device,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+	unsigned long tmp_curves[FBTFT_GAMMA_MAX_VALUES_TOTAL];
+	int ret;
+
+	ret = fbtft_gamma_parse_str(par, tmp_curves, buf, count);
+	if (ret)
+		return ret;
+
+	ret = par->fbtftops.set_gamma(par, tmp_curves);
+	if (ret)
+		return ret;
+
+	mutex_lock(&par->gamma.lock);
+	memcpy(par->gamma.curves, tmp_curves,
+		par->gamma.num_curves * par->gamma.num_values * sizeof(tmp_curves[0]));
+	mutex_unlock(&par->gamma.lock);
+
+	return count;
+}
+
+static ssize_t show_gamma_curve(struct device *device,
+				struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+
+	return sprintf_gamma(par, par->gamma.curves, buf);
+}
+
+static struct device_attribute gamma_device_attrs[] = {
+	__ATTR(gamma, 0660, show_gamma_curve, store_gamma_curve),
+};
+
+
+void fbtft_expand_debug_value(unsigned long *debug)
+{
+	switch (*debug & 0b111) {
+	case 1:
+		*debug |= DEBUG_LEVEL_1;
+		break;
+	case 2:
+		*debug |= DEBUG_LEVEL_2;
+		break;
+	case 3:
+		*debug |= DEBUG_LEVEL_3;
+		break;
+	case 4:
+		*debug |= DEBUG_LEVEL_4;
+		break;
+	case 5:
+		*debug |= DEBUG_LEVEL_5;
+		break;
+	case 6:
+		*debug |= DEBUG_LEVEL_6;
+		break;
+	case 7:
+		*debug = 0xFFFFFFFF;
+		break;
+	}
+}
+
+static ssize_t store_debug(struct device *device,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &par->debug);
+	if (ret)
+		return ret;
+	fbtft_expand_debug_value(&par->debug);
+
+	return count;
+}
+
+static ssize_t show_debug(struct device *device,
+				struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+
+	return snprintf(buf, PAGE_SIZE, "%lu\n", par->debug);
+}
+
+static struct device_attribute debug_device_attr = \
+	__ATTR(debug, 0660, show_debug, store_debug);
+
+
+void fbtft_sysfs_init(struct fbtft_par *par)
+{
+	device_create_file(par->info->dev, &debug_device_attr);
+	if (par->gamma.curves && par->fbtftops.set_gamma)
+		device_create_file(par->info->dev, &gamma_device_attrs[0]);
+}
+
+void fbtft_sysfs_exit(struct fbtft_par *par)
+{
+	device_remove_file(par->info->dev, &debug_device_attr);
+	if (par->gamma.curves && par->fbtftops.set_gamma)
+		device_remove_file(par->info->dev, &gamma_device_attrs[0]);
+}

drivers/staging/fbtft/fbtft.h

+/*
+ * Copyright (C) 2013 Noralf Tronnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __LINUX_FBTFT_H
+#define __LINUX_FBTFT_H
+
+#include <linux/fb.h>
+#include <linux/spinlock.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_device.h>
+
+
+#define FBTFT_NOP		0x00
+#define FBTFT_SWRESET	0x01
+#define FBTFT_RDDID		0x04
+#define FBTFT_RDDST		0x09
+#define FBTFT_CASET		0x2A
+#define FBTFT_RASET		0x2B
+#define FBTFT_RAMWR		0x2C
+
+#define FBTFT_ONBOARD_BACKLIGHT 2
+
+#define FBTFT_GPIO_NO_MATCH		0xFFFF
+#define FBTFT_GPIO_NAME_SIZE	32
+#define FBTFT_MAX_INIT_SEQUENCE      512
+#define FBTFT_GAMMA_MAX_VALUES_TOTAL 128
+
+#define FBTFT_OF_INIT_CMD	BIT(24)
+#define FBTFT_OF_INIT_DELAY	BIT(25)
+
+/**
+ * struct fbtft_gpio - Structure that holds one pinname to gpio mapping
+ * @name: pinname (reset, dc, etc.)
+ * @gpio: GPIO number
+ *
+ */
+struct fbtft_gpio {
+	char name[FBTFT_GPIO_NAME_SIZE];
+	unsigned gpio;
+};
+
+struct fbtft_par;
+
+/**
+ * struct fbtft_ops - FBTFT operations structure
+ * @write: Writes to interface bus
+ * @read: Reads from interface bus
+ * @write_vmem: Writes video memory to display
+ * @write_reg: Writes to controller register
+ * @set_addr_win: Set the GRAM update window
+ * @reset: Reset the LCD controller
+ * @mkdirty: Marks display lines for update
+ * @update_display: Updates the display
+ * @init_display: Initializes the display
+ * @blank: Blank the display (optional)
+ * @request_gpios_match: Do pinname to gpio matching
+ * @request_gpios: Request gpios from the kernel
+ * @free_gpios: Free previously requested gpios
+ * @verify_gpios: Verify that necessary gpios is present (optional)
+ * @register_backlight: Used to register backlight device (optional)
+ * @unregister_backlight: Unregister backlight device (optional)
+ * @set_var: Configure LCD with values from variables like @rotate and @bgr
+ *           (optional)
+ * @set_gamma: Set Gamma curve (optional)
+ *
+ * Most of these operations have default functions assigned to them in
+ *     fbtft_framebuffer_alloc()
+ */
+struct fbtft_ops {
+	int (*write)(struct fbtft_par *par, void *buf, size_t len);
+	int (*read)(struct fbtft_par *par, void *buf, size_t len);
+	int (*write_vmem)(struct fbtft_par *par, size_t offset, size_t len);
+	void (*write_register)(struct fbtft_par *par, int len, ...);
+
+	void (*set_addr_win)(struct fbtft_par *par,
+		int xs, int ys, int xe, int ye);
+	void (*reset)(struct fbtft_par *par);
+	void (*mkdirty)(struct fb_info *info, int from, int to);
+	void (*update_display)(struct fbtft_par *par,
+				unsigned start_line, unsigned end_line);
+	int (*init_display)(struct fbtft_par *par);
+	int (*blank)(struct fbtft_par *par, bool on);
+
+	unsigned long (*request_gpios_match)(struct fbtft_par *par,
+		const struct fbtft_gpio *gpio);
+	int (*request_gpios)(struct fbtft_par *par);
+	int (*verify_gpios)(struct fbtft_par *par);
+
+	void (*register_backlight)(struct fbtft_par *par);
+	void (*unregister_backlight)(struct fbtft_par *par);
+
+	int (*set_var)(struct fbtft_par *par);
+	int (*set_gamma)(struct fbtft_par *par, unsigned long *curves);
+};
+
+/**
+ * struct fbtft_display - Describes the display properties
+ * @width: Width of display in pixels
+ * @height: Height of display in pixels
+ * @regwidth: LCD Controller Register width in bits
+ * @buswidth: Display interface bus width in bits
+ * @backlight: Backlight type.
+ * @fbtftops: FBTFT operations provided by driver or device (platform_data)
+ * @bpp: Bits per pixel
+ * @fps: Frames per second
+ * @txbuflen: Size of transmit buffer
+ * @init_sequence: Pointer to LCD initialization array
+ * @gamma: String representation of Gamma curve(s)
+ * @gamma_num: Number of Gamma curves
+ * @gamma_len: Number of values per Gamma curve
+ * @debug: Initial debug value
+ *
+ * This structure is not stored by FBTFT except for init_sequence.
+ */
+struct fbtft_display {
+	unsigned width;
+	unsigned height;
+	unsigned regwidth;
+	unsigned buswidth;
+	unsigned backlight;
+	struct fbtft_ops fbtftops;
+	unsigned bpp;
+	unsigned fps;
+	int txbuflen;
+	int *init_sequence;
+	char *gamma;
+	int gamma_num;
+	int gamma_len;
+	unsigned long debug;
+};
+
+/**
+ * struct fbtft_platform_data - Passes display specific data to the driver
+ * @display: Display properties
+ * @gpios: Pointer to an array of piname to gpio mappings
+ * @rotate: Display rotation angle
+ * @bgr: LCD Controller BGR bit
+ * @fps: Frames per second (this will go away, use @fps in @fbtft_display)
+ * @txbuflen: Size of transmit buffer
+ * @startbyte: When set, enables use of Startbyte in transfers
+ * @gamma: String representation of Gamma curve(s)
+ * @extra: A way to pass extra info
+ */
+struct fbtft_platform_data {
+	struct fbtft_display display;
+	const struct fbtft_gpio *gpios;
+	unsigned rotate;
+	bool bgr;
+	unsigned fps;
+	int txbuflen;
+	u8 startbyte;
+	char *gamma;
+	void *extra;
+};
+
+/**
+ * struct fbtft_par - Main FBTFT data structure
+ *
+ * This structure holds all relevant data to operate the display
+ *
+ * See sourcefile for documentation since nested structs is not
+ * supported by kernel-doc.
+ *
+ */
+/* @spi: Set if it is a SPI device
+ * @pdev: Set if it is a platform device
+ * @info: Pointer to framebuffer fb_info structure
+ * @pdata: Pointer to platform data
+ * @ssbuf: Not used
+ * @pseudo_palette: Used by fb_set_colreg()
+ * @txbuf.buf: Transmit buffer
+ * @txbuf.len: Transmit buffer length
+ * @buf: Small buffer used when writing init data over SPI
+ * @startbyte: Used by some controllers when in SPI mode.
+ *             Format: 6 bit Device id + RS bit + RW bit
+ * @fbtftops: FBTFT operations provided by driver or device (platform_data)
+ * @dirty_lock: Protects dirty_lines_start and dirty_lines_end
+ * @dirty_lines_start: Where to begin updating display
+ * @dirty_lines_end: Where to end updating display
+ * @gpio.reset: GPIO used to reset display
+ * @gpio.dc: Data/Command signal, also known as RS
+ * @gpio.rd: Read latching signal
+ * @gpio.wr: Write latching signal
+ * @gpio.latch: Bus latch signal, eg. 16->8 bit bus latch
+ * @gpio.cs: LCD Chip Select with parallel interface bus
+ * @gpio.db[16]: Parallel databus
+ * @gpio.led[16]: Led control signals
+ * @gpio.aux[16]: Auxillary signals, not used by core
+ * @init_sequence: Pointer to LCD initialization array
+ * @gamma.lock: Mutex for Gamma curve locking
+ * @gamma.curves: Pointer to Gamma curve array
+ * @gamma.num_values: Number of values per Gamma curve
+ * @gamma.num_curves: Number of Gamma curves
+ * @debug: Pointer to debug value
+ * @current_debug:
+ * @first_update_done: Used to only time the first display update
+ * @update_time: Used to calculate 'fps' in debug output
+ * @bgr: BGR mode/\n
+ * @extra: Extra info needed by driver
+ */
+struct fbtft_par {
+	struct spi_device *spi;
+	struct platform_device *pdev;
+	struct fb_info *info;
+	struct fbtft_platform_data *pdata;
+	u16 *ssbuf;
+	u32 pseudo_palette[16];
+	struct {
+		void *buf;
+		dma_addr_t dma;
+		size_t len;
+	} txbuf;
+	u8 *buf;
+	u8 startbyte;
+	struct fbtft_ops fbtftops;
+	spinlock_t dirty_lock;
+	unsigned dirty_lines_start;
+	unsigned dirty_lines_end;
+	struct {
+		int reset;
+		int dc;
+		int rd;
+		int wr;
+		int latch;
+		int cs;
+		int db[16];
+		int led[16];
+		int aux[16];
+	} gpio;
+	int *init_sequence;
+	struct {
+		struct mutex lock;
+		unsigned long *curves;
+		int num_values;
+		int num_curves;
+	} gamma;
+	unsigned long debug;
+	bool first_update_done;
+	struct timespec update_time;
+	bool bgr;
+	void *extra;
+};
+
+#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__})/sizeof(int))
+
+#define write_reg(par, ...)                                              \
+do {                                                                     \
+	par->fbtftops.write_register(par, NUMARGS(__VA_ARGS__), __VA_ARGS__); \
+} while (0)
+
+/* fbtft-core.c */
+extern void fbtft_dbg_hex(const struct device *dev,
+	int groupsize, void *buf, size_t len, const char *fmt, ...);
+extern struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
+	struct device *dev);
+extern void fbtft_framebuffer_release(struct fb_info *info);
+extern int fbtft_register_framebuffer(struct fb_info *fb_info);
+extern int fbtft_unregister_framebuffer(struct fb_info *fb_info);
+extern void fbtft_register_backlight(struct fbtft_par *par);
+extern void fbtft_unregister_backlight(struct fbtft_par *par);
+extern int fbtft_init_display(struct fbtft_par *par);
+extern int fbtft_probe_common(struct fbtft_display *display,
+	struct spi_device *sdev, struct platform_device *pdev);
+extern int fbtft_remove_common(struct device *dev, struct fb_info *info);
+
+/* fbtft-io.c */
+extern int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len);
+extern int fbtft_write_spi_emulate_9(struct fbtft_par *par,
+	void *buf, size_t len);
+extern int fbtft_read_spi(struct fbtft_par *par, void *buf, size_t len);
+extern int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len);
+extern int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len);
+extern int fbtft_write_gpio16_wr_latched(struct fbtft_par *par,
+	void *buf, size_t len);
+
+/* fbtft-bus.c */
+extern int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len);
+extern int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len);
+extern int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len);
+extern int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len);
+extern void fbtft_write_reg8_bus8(struct fbtft_par *par, int len, ...);
+extern void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...);
+extern void fbtft_write_reg16_bus8(struct fbtft_par *par, int len, ...);
+extern void fbtft_write_reg16_bus16(struct fbtft_par *par, int len, ...);
+
+
+#define FBTFT_REGISTER_DRIVER(_name, _compatible, _display)                \
+									   \
+static int fbtft_driver_probe_spi(struct spi_device *spi)                  \
+{                                                                          \
+	return fbtft_probe_common(_display, spi, NULL);                    \
+}                                                                          \
+									   \
+static int fbtft_driver_remove_spi(struct spi_device *spi)                 \
+{                                                                          \
+	struct fb_info *info = spi_get_drvdata(spi);                       \
+									   \
+	return fbtft_remove_common(&spi->dev, info);                       \
+}                                                                          \
+									   \
+static int fbtft_driver_probe_pdev(struct platform_device *pdev)           \
+{                                                                          \
+	return fbtft_probe_common(_display, NULL, pdev);                   \
+}                                                                          \
+									   \
+static int fbtft_driver_remove_pdev(struct platform_device *pdev)          \
+{                                                                          \
+	struct fb_info *info = platform_get_drvdata(pdev);                 \
+									   \
+	return fbtft_remove_common(&pdev->dev, info);                      \
+}                                                                          \
+									   \
+static const struct of_device_id dt_ids[] = {                              \
+        { .compatible = _compatible },                                     \
+        {},                                                                \
+};                                                                         \
+									   \
+MODULE_DEVICE_TABLE(of, dt_ids);                                           \
+									   \
+									   \
+static struct spi_driver fbtft_driver_spi_driver = {                       \
+	.driver = {                                                        \
+		.name   = _name,                                           \
+		.owner  = THIS_MODULE,                                     \
+                .of_match_table = of_match_ptr(dt_ids),                    \
+	},                                                                 \
+	.probe  = fbtft_driver_probe_spi,                                  \
+	.remove = fbtft_driver_remove_spi,                                 \
+};                                                                         \
+									   \
+static struct platform_driver fbtft_driver_platform_driver = {             \
+	.driver = {                                                        \
+		.name   = _name,                                           \
+		.owner  = THIS_MODULE,                                     \
+                .of_match_table = of_match_ptr(dt_ids),                    \
+	},                                                                 \
+	.probe  = fbtft_driver_probe_pdev,                                 \
+	.remove = fbtft_driver_remove_pdev,                                \
+};                                                                         \
+									   \
+static int __init fbtft_driver_module_init(void)                           \
+{                                                                          \
+	int ret;                                                           \
+									   \
+	ret = spi_register_driver(&fbtft_driver_spi_driver);               \
+	if (ret < 0)                                                       \
+		return ret;                                                \
+	return platform_driver_register(&fbtft_driver_platform_driver);    \
+}                                                                          \
+									   \
+static void __exit fbtft_driver_module_exit(void)                          \
+{                                                                          \
+	spi_unregister_driver(&fbtft_driver_spi_driver);                   \
+	platform_driver_unregister(&fbtft_driver_platform_driver);         \
+}                                                                          \
+									   \
+module_init(fbtft_driver_module_init);                                     \
+module_exit(fbtft_driver_module_exit);
+
+
+/* Debug macros */
+
+/* shorthand debug levels */
+#define DEBUG_LEVEL_1	DEBUG_REQUEST_GPIOS
+#define DEBUG_LEVEL_2	(DEBUG_LEVEL_1 | DEBUG_DRIVER_INIT_FUNCTIONS | DEBUG_TIME_FIRST_UPDATE)
+#define DEBUG_LEVEL_3	(DEBUG_LEVEL_2 | DEBUG_RESET | DEBUG_INIT_DISPLAY | DEBUG_BLANK | DEBUG_REQUEST_GPIOS | DEBUG_FREE_GPIOS | DEBUG_VERIFY_GPIOS | DEBUG_BACKLIGHT | DEBUG_SYSFS)
+#define DEBUG_LEVEL_4	(DEBUG_LEVEL_2 | DEBUG_FB_READ | DEBUG_FB_WRITE | DEBUG_FB_FILLRECT | DEBUG_FB_COPYAREA | DEBUG_FB_IMAGEBLIT | DEBUG_FB_BLANK)
+#define DEBUG_LEVEL_5	(DEBUG_LEVEL_3 | DEBUG_UPDATE_DISPLAY)
+#define DEBUG_LEVEL_6	(DEBUG_LEVEL_4 | DEBUG_LEVEL_5)
+#define DEBUG_LEVEL_7	0xFFFFFFFF
+
+#define DEBUG_DRIVER_INIT_FUNCTIONS (1<<3)
+#define DEBUG_TIME_FIRST_UPDATE     (1<<4)
+#define DEBUG_TIME_EACH_UPDATE      (1<<5)
+#define DEBUG_DEFERRED_IO           (1<<6)
+#define DEBUG_FBTFT_INIT_FUNCTIONS  (1<<7)
+
+/* fbops */
+#define DEBUG_FB_READ               (1<<8)
+#define DEBUG_FB_WRITE              (1<<9)
+#define DEBUG_FB_FILLRECT           (1<<10)
+#define DEBUG_FB_COPYAREA           (1<<11)
+#define DEBUG_FB_IMAGEBLIT          (1<<12)
+#define DEBUG_FB_SETCOLREG          (1<<13)
+#define DEBUG_FB_BLANK              (1<<14)
+
+#define DEBUG_SYSFS                 (1<<16)
+
+/* fbtftops */
+#define DEBUG_BACKLIGHT             (1<<17)
+#define DEBUG_READ                  (1<<18)
+#define DEBUG_WRITE                 (1<<19)
+#define DEBUG_WRITE_VMEM            (1<<20)
+#define DEBUG_WRITE_REGISTER        (1<<21)
+#define DEBUG_SET_ADDR_WIN          (1<<22)
+#define DEBUG_RESET                 (1<<23)
+#define DEBUG_MKDIRTY               (1<<24)
+#define DEBUG_UPDATE_DISPLAY        (1<<25)
+#define DEBUG_INIT_DISPLAY          (1<<26)
+#define DEBUG_BLANK                 (1<<27)
+#define DEBUG_REQUEST_GPIOS         (1<<28)
+#define DEBUG_FREE_GPIOS            (1<<29)
+#define DEBUG_REQUEST_GPIOS_MATCH   (1<<30)
+#define DEBUG_VERIFY_GPIOS          (1<<31)
+
+
+#define fbtft_init_dbg(dev, format, arg...)                  \
+do {                                                         \
+	if (unlikely((dev)->platform_data &&                 \
+	    (((struct fbtft_platform_data *)(dev)->platform_data)->display.debug & DEBUG_DRIVER_INIT_FUNCTIONS))) \
+		dev_info(dev, format, ##arg);                \
+} while (0)
+
+#define fbtft_par_dbg(level, par, format, arg...)            \
+do {                                                         \
+	if (unlikely(par->debug & level))                    \
+		dev_info(par->info->device, format, ##arg);  \
+} while (0)
+
+#define fbtft_dev_dbg(level, par, dev, format, arg...)       \
+do {                                                         \
+	if (unlikely(par->debug & level))                    \
+		dev_info(dev, format, ##arg);                \
+} while (0)
+
+#define fbtft_par_dbg_hex(level, par, dev, type, buf, num, format, arg...) \
+do {                                                                       \
+	if (unlikely(par->debug & level))                                  \
+		fbtft_dbg_hex(dev, sizeof(type), buf, num * sizeof(type), format, ##arg); \
+} while (0)
+
+#endif /* __LINUX_FBTFT_H */