/*
   * Common code for AUO-K190X framebuffer drivers
   *
   * Copyright (C) 2012 Heiko Stuebner <heiko@sntech.de>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/gpio.h>
  #include <linux/platform_device.h>
  #include <linux/pm_runtime.h>
  #include <linux/fb.h>
  #include <linux/delay.h>
  #include <linux/uaccess.h>
  #include <linux/vmalloc.h>
  #include <linux/regulator/consumer.h>
  
  #include <video/auo_k190xfb.h>
  
  #include "auo_k190x.h"
  
  struct panel_info {
  	int w;
  	int h;
  };
  
  /* table of panel specific parameters to be indexed into by the board drivers */
  static struct panel_info panel_table[] = {
  	/* standard 6" */
  	[AUOK190X_RESOLUTION_800_600] = {
  		.w = 800,
  		.h = 600,
  	},
  	/* standard 9" */
  	[AUOK190X_RESOLUTION_1024_768] = {
  		.w = 1024,
  		.h = 768,
  	},
  	[AUOK190X_RESOLUTION_600_800] = {
  		.w = 600,
  		.h = 800,
  	},
  	[AUOK190X_RESOLUTION_768_1024] = {
  		.w = 768,
  		.h = 1024,
  	},
  };
  
  /*
   * private I80 interface to the board driver
   */
  
  static void auok190x_issue_data(struct auok190xfb_par *par, u16 data)
  {
  	par->board->set_ctl(par, AUOK190X_I80_WR, 0);
  	par->board->set_hdb(par, data);
  	par->board->set_ctl(par, AUOK190X_I80_WR, 1);
  }
  
  static void auok190x_issue_cmd(struct auok190xfb_par *par, u16 data)
  {
  	par->board->set_ctl(par, AUOK190X_I80_DC, 0);
  	auok190x_issue_data(par, data);
  	par->board->set_ctl(par, AUOK190X_I80_DC, 1);
  }
  
  /**
   * Conversion of 16bit color to 4bit grayscale
   * does roughly (0.3 * R + 0.6 G + 0.1 B) / 2
   */
  static inline int rgb565_to_gray4(u16 data, struct fb_var_screeninfo *var)
  {
  	return ((((data & 0xF800) >> var->red.offset) * 77 +
  		 ((data & 0x07E0) >> (var->green.offset + 1)) * 151 +
  		 ((data & 0x1F) >> var->blue.offset) * 28) >> 8 >> 1);
  }
  
  static int auok190x_issue_pixels_rgb565(struct auok190xfb_par *par, int size,
  					u16 *data)
  {
  	struct fb_var_screeninfo *var = &par->info->var;
  	struct device *dev = par->info->device;
  	int i;
  	u16 tmp;
  
  	if (size & 7) {
  		dev_err(dev, "issue_pixels: size %d must be a multiple of 8
  ",
  			size);
  		return -EINVAL;
  	}
  
  	for (i = 0; i < (size >> 2); i++) {
  		par->board->set_ctl(par, AUOK190X_I80_WR, 0);
  
  		tmp  = (rgb565_to_gray4(data[4*i], var) & 0x000F);
  		tmp |= (rgb565_to_gray4(data[4*i+1], var) << 4) & 0x00F0;
  		tmp |= (rgb565_to_gray4(data[4*i+2], var) << 8) & 0x0F00;
  		tmp |= (rgb565_to_gray4(data[4*i+3], var) << 12) & 0xF000;
  
  		par->board->set_hdb(par, tmp);
  		par->board->set_ctl(par, AUOK190X_I80_WR, 1);
  	}
  
  	return 0;
  }
  
  static int auok190x_issue_pixels_gray8(struct auok190xfb_par *par, int size,
  				       u16 *data)
  {
  	struct device *dev = par->info->device;
  	int i;
  	u16 tmp;
  
  	if (size & 3) {
  		dev_err(dev, "issue_pixels: size %d must be a multiple of 4
  ",
  			size);
  		return -EINVAL;
  	}
  
  	for (i = 0; i < (size >> 1); i++) {
  		par->board->set_ctl(par, AUOK190X_I80_WR, 0);
  
  		/* simple reduction of 8bit staticgray to 4bit gray
  		 * combines 4 * 4bit pixel values into a 16bit value
  		 */
  		tmp  = (data[2*i] & 0xF0) >> 4;
  		tmp |= (data[2*i] & 0xF000) >> 8;
  		tmp |= (data[2*i+1] & 0xF0) << 4;
  		tmp |= (data[2*i+1] & 0xF000);
  
  		par->board->set_hdb(par, tmp);
  		par->board->set_ctl(par, AUOK190X_I80_WR, 1);
  	}
  
  	return 0;
  }
  
  static int auok190x_issue_pixels(struct auok190xfb_par *par, int size,
  				 u16 *data)
  {
  	struct fb_info *info = par->info;
  	struct device *dev = par->info->device;
  
  	if (info->var.bits_per_pixel == 8 && info->var.grayscale)
  		auok190x_issue_pixels_gray8(par, size, data);
  	else if (info->var.bits_per_pixel == 16)
  		auok190x_issue_pixels_rgb565(par, size, data);
  	else
  		dev_err(dev, "unsupported color mode (bits: %d, gray: %d)
  ",
  			info->var.bits_per_pixel, info->var.grayscale);
  
  	return 0;
  }
  
  static u16 auok190x_read_data(struct auok190xfb_par *par)
  {
  	u16 data;
  
  	par->board->set_ctl(par, AUOK190X_I80_OE, 0);
  	data = par->board->get_hdb(par);
  	par->board->set_ctl(par, AUOK190X_I80_OE, 1);
  
  	return data;
  }
  
  /*
   * Command interface for the controller drivers
   */
  
  void auok190x_send_command_nowait(struct auok190xfb_par *par, u16 data)
  {
  	par->board->set_ctl(par, AUOK190X_I80_CS, 0);
  	auok190x_issue_cmd(par, data);
  	par->board->set_ctl(par, AUOK190X_I80_CS, 1);
  }
  EXPORT_SYMBOL_GPL(auok190x_send_command_nowait);
  
  void auok190x_send_cmdargs_nowait(struct auok190xfb_par *par, u16 cmd,
  				  int argc, u16 *argv)
  {
  	int i;
  
  	par->board->set_ctl(par, AUOK190X_I80_CS, 0);
  	auok190x_issue_cmd(par, cmd);
  
  	for (i = 0; i < argc; i++)
  		auok190x_issue_data(par, argv[i]);
  	par->board->set_ctl(par, AUOK190X_I80_CS, 1);
  }
  EXPORT_SYMBOL_GPL(auok190x_send_cmdargs_nowait);
  
  int auok190x_send_command(struct auok190xfb_par *par, u16 data)
  {
  	int ret;
  
  	ret = par->board->wait_for_rdy(par);
  	if (ret)
  		return ret;
  
  	auok190x_send_command_nowait(par, data);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(auok190x_send_command);
  
  int auok190x_send_cmdargs(struct auok190xfb_par *par, u16 cmd,
  			   int argc, u16 *argv)
  {
  	int ret;
  
  	ret = par->board->wait_for_rdy(par);
  	if (ret)
  		return ret;
  
  	auok190x_send_cmdargs_nowait(par, cmd, argc, argv);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(auok190x_send_cmdargs);
  
  int auok190x_read_cmdargs(struct auok190xfb_par *par, u16 cmd,
  			   int argc, u16 *argv)
  {
  	int i, ret;
  
  	ret = par->board->wait_for_rdy(par);
  	if (ret)
  		return ret;
  
  	par->board->set_ctl(par, AUOK190X_I80_CS, 0);
  	auok190x_issue_cmd(par, cmd);
  
  	for (i = 0; i < argc; i++)
  		argv[i] = auok190x_read_data(par);
  	par->board->set_ctl(par, AUOK190X_I80_CS, 1);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(auok190x_read_cmdargs);
  
  void auok190x_send_cmdargs_pixels_nowait(struct auok190xfb_par *par, u16 cmd,
  				  int argc, u16 *argv, int size, u16 *data)
  {
  	int i;
  
  	par->board->set_ctl(par, AUOK190X_I80_CS, 0);
  
  	auok190x_issue_cmd(par, cmd);
  
  	for (i = 0; i < argc; i++)
  		auok190x_issue_data(par, argv[i]);
  
  	auok190x_issue_pixels(par, size, data);
  
  	par->board->set_ctl(par, AUOK190X_I80_CS, 1);
  }
  EXPORT_SYMBOL_GPL(auok190x_send_cmdargs_pixels_nowait);
  
  int auok190x_send_cmdargs_pixels(struct auok190xfb_par *par, u16 cmd,
  				  int argc, u16 *argv, int size, u16 *data)
  {
  	int ret;
  
  	ret = par->board->wait_for_rdy(par);
  	if (ret)
  		return ret;
  
  	auok190x_send_cmdargs_pixels_nowait(par, cmd, argc, argv, size, data);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(auok190x_send_cmdargs_pixels);
  
  /*
   * fbdefio callbacks - common on both controllers.
   */
  
  static void auok190xfb_dpy_first_io(struct fb_info *info)
  {
  	/* tell runtime-pm that we wish to use the device in a short time */
  	pm_runtime_get(info->device);
  }
  
  /* this is called back from the deferred io workqueue */
  static void auok190xfb_dpy_deferred_io(struct fb_info *info,
  				struct list_head *pagelist)
  {
  	struct fb_deferred_io *fbdefio = info->fbdefio;
  	struct auok190xfb_par *par = info->par;
  	u16 line_length = info->fix.line_length;
  	u16 yres = info->var.yres;
  	u16 y1 = 0, h = 0;
  	int prev_index = -1;
  	struct page *cur;
  	int h_inc;
  	int threshold;
  
  	if (!list_empty(pagelist))
  		/* the device resume should've been requested through first_io,
  		 * if the resume did not finish until now, wait for it.
  		 */
  		pm_runtime_barrier(info->device);
  	else
  		/* We reached this via the fsync or some other way.
  		 * In either case the first_io function did not run,
  		 * so we runtime_resume the device here synchronously.
  		 */
  		pm_runtime_get_sync(info->device);
  
  	/* Do a full screen update every n updates to prevent
  	 * excessive darkening of the Sipix display.
  	 * If we do this, there is no need to walk the pages.
  	 */
  	if (par->need_refresh(par)) {
  		par->update_all(par);
  		goto out;
  	}
  
  	/* height increment is fixed per page */
  	h_inc = DIV_ROUND_UP(PAGE_SIZE , line_length);
  
  	/* calculate number of pages from pixel height */
  	threshold = par->consecutive_threshold / h_inc;
  	if (threshold < 1)
  		threshold = 1;
  
  	/* walk the written page list and swizzle the data */
  	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
  		if (prev_index < 0) {
  			/* just starting so assign first page */
  			y1 = (cur->index << PAGE_SHIFT) / line_length;
  			h = h_inc;
  		} else if ((cur->index - prev_index) <= threshold) {
  			/* page is within our threshold for single updates */
  			h += h_inc * (cur->index - prev_index);
  		} else {
  			/* page not consecutive, issue previous update first */
  			par->update_partial(par, y1, y1 + h);
  
  			/* start over with our non consecutive page */
  			y1 = (cur->index << PAGE_SHIFT) / line_length;
  			h = h_inc;
  		}
  		prev_index = cur->index;
  	}
  
  	/* if we still have any pages to update we do so now */
  	if (h >= yres)
  		/* its a full screen update, just do it */
  		par->update_all(par);
  	else
  		par->update_partial(par, y1, min((u16) (y1 + h), yres));
  
  out:
  	pm_runtime_mark_last_busy(info->device);
  	pm_runtime_put_autosuspend(info->device);
  }
  
  /*
   * framebuffer operations
   */
  
  /*
   * this is the slow path from userspace. they can seek and write to
   * the fb. it's inefficient to do anything less than a full screen draw
   */
  static ssize_t auok190xfb_write(struct fb_info *info, const char __user *buf,
  				size_t count, loff_t *ppos)
  {
  	struct auok190xfb_par *par = info->par;
  	unsigned long p = *ppos;
  	void *dst;
  	int err = 0;
  	unsigned long total_size;
  
  	if (info->state != FBINFO_STATE_RUNNING)
  		return -EPERM;
  
  	total_size = info->fix.smem_len;
  
  	if (p > total_size)
  		return -EFBIG;
  
  	if (count > total_size) {
  		err = -EFBIG;
  		count = total_size;
  	}
  
  	if (count + p > total_size) {
  		if (!err)
  			err = -ENOSPC;
  
  		count = total_size - p;
  	}
  
  	dst = (void *)(info->screen_base + p);
  
  	if (copy_from_user(dst, buf, count))
  		err = -EFAULT;
  
  	if  (!err)
  		*ppos += count;
  
  	par->update_all(par);
  
  	return (err) ? err : count;
  }
  
  static void auok190xfb_fillrect(struct fb_info *info,
  				   const struct fb_fillrect *rect)
  {
  	struct auok190xfb_par *par = info->par;
  
  	sys_fillrect(info, rect);
  
  	par->update_all(par);
  }
  
  static void auok190xfb_copyarea(struct fb_info *info,
  				   const struct fb_copyarea *area)
  {
  	struct auok190xfb_par *par = info->par;
  
  	sys_copyarea(info, area);
  
  	par->update_all(par);
  }
  
  static void auok190xfb_imageblit(struct fb_info *info,
  				const struct fb_image *image)
  {
  	struct auok190xfb_par *par = info->par;
  
  	sys_imageblit(info, image);
  
  	par->update_all(par);
  }
  
  static int auok190xfb_check_var(struct fb_var_screeninfo *var,
  				   struct fb_info *info)
  {
  	struct device *dev = info->device;
  	struct auok190xfb_par *par = info->par;
  	struct panel_info *panel = &panel_table[par->resolution];
  	int size;
  
  	/*
  	 * Color depth
  	 */
  
  	if (var->bits_per_pixel == 8 && var->grayscale == 1) {
  		/*
  		 * For 8-bit grayscale, R, G, and B offset are equal.
  		 */
  		var->red.length = 8;
  		var->red.offset = 0;
  		var->red.msb_right = 0;
  
  		var->green.length = 8;
  		var->green.offset = 0;
  		var->green.msb_right = 0;
  
  		var->blue.length = 8;
  		var->blue.offset = 0;
  		var->blue.msb_right = 0;
  
  		var->transp.length = 0;
  		var->transp.offset = 0;
  		var->transp.msb_right = 0;
  	} else if (var->bits_per_pixel == 16) {
  		var->red.length = 5;
  		var->red.offset = 11;
  		var->red.msb_right = 0;
  
  		var->green.length = 6;
  		var->green.offset = 5;
  		var->green.msb_right = 0;
  
  		var->blue.length = 5;
  		var->blue.offset = 0;
  		var->blue.msb_right = 0;
  
  		var->transp.length = 0;
  		var->transp.offset = 0;
  		var->transp.msb_right = 0;
  	} else {
  		dev_warn(dev, "unsupported color mode (bits: %d, grayscale: %d)
  ",
  			info->var.bits_per_pixel, info->var.grayscale);
  		return -EINVAL;
  	}
  
  	/*
  	 * Dimensions
  	 */
  
  	switch (var->rotate) {
  	case FB_ROTATE_UR:
  	case FB_ROTATE_UD:
  		var->xres = panel->w;
  		var->yres = panel->h;
  		break;
  	case FB_ROTATE_CW:
  	case FB_ROTATE_CCW:
  		var->xres = panel->h;
  		var->yres = panel->w;
  		break;
  	default:
  		dev_dbg(dev, "Invalid rotation request
  ");
  		return -EINVAL;
  	}
  
  	var->xres_virtual = var->xres;
  	var->yres_virtual = var->yres;
  
  	/*
  	 *  Memory limit
  	 */
  
  	size = var->xres_virtual * var->yres_virtual * var->bits_per_pixel / 8;
  	if (size > info->fix.smem_len) {
  		dev_err(dev, "Memory limit exceeded, requested %dK
  ",
  			size >> 10);
  		return -ENOMEM;
  	}
  
  	return 0;
  }
  
  static int auok190xfb_set_fix(struct fb_info *info)
  {
  	struct fb_fix_screeninfo *fix = &info->fix;
  	struct fb_var_screeninfo *var = &info->var;
  
  	fix->line_length = var->xres_virtual * var->bits_per_pixel / 8;
  
  	fix->type = FB_TYPE_PACKED_PIXELS;
  	fix->accel = FB_ACCEL_NONE;
  	fix->visual = (var->grayscale) ? FB_VISUAL_STATIC_PSEUDOCOLOR
  				       : FB_VISUAL_TRUECOLOR;
  	fix->xpanstep = 0;
  	fix->ypanstep = 0;
  	fix->ywrapstep = 0;
  
  	return 0;
  }
  
  static int auok190xfb_set_par(struct fb_info *info)
  {
  	struct auok190xfb_par *par = info->par;
  
  	par->rotation = info->var.rotate;
  	auok190xfb_set_fix(info);
  
  	/* reinit the controller to honor the rotation */
  	par->init(par);
  
  	/* wait for init to complete */
  	par->board->wait_for_rdy(par);
  
  	return 0;
  }
  
  static struct fb_ops auok190xfb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_read	= fb_sys_read,
  	.fb_write	= auok190xfb_write,
  	.fb_fillrect	= auok190xfb_fillrect,
  	.fb_copyarea	= auok190xfb_copyarea,
  	.fb_imageblit	= auok190xfb_imageblit,
  	.fb_check_var	= auok190xfb_check_var,
  	.fb_set_par     = auok190xfb_set_par,
  };
  
  /*
   * Controller-functions common to both K1900 and K1901
   */
  
  static int auok190x_read_temperature(struct auok190xfb_par *par)
  {
  	struct device *dev = par->info->device;
  	u16 data[4];
  	int temp;
  
  	pm_runtime_get_sync(dev);
  
  	mutex_lock(&(par->io_lock));
  
  	auok190x_read_cmdargs(par, AUOK190X_CMD_READ_VERSION, 4, data);
  
  	mutex_unlock(&(par->io_lock));
  
  	pm_runtime_mark_last_busy(dev);
  	pm_runtime_put_autosuspend(dev);
  
  	/* sanitize and split of half-degrees for now */
  	temp = ((data[0] & AUOK190X_VERSION_TEMP_MASK) >> 1);
  
  	/* handle positive and negative temperatures */
  	if (temp >= 201)
  		return (255 - temp + 1) * (-1);
  	else
  		return temp;
  }
  
  static void auok190x_identify(struct auok190xfb_par *par)
  {
  	struct device *dev = par->info->device;
  	u16 data[4];
  
  	pm_runtime_get_sync(dev);
  
  	mutex_lock(&(par->io_lock));
  
  	auok190x_read_cmdargs(par, AUOK190X_CMD_READ_VERSION, 4, data);
  
  	mutex_unlock(&(par->io_lock));
  
  	par->epd_type = data[1] & AUOK190X_VERSION_TEMP_MASK;
  
  	par->panel_size_int = AUOK190X_VERSION_SIZE_INT(data[2]);
  	par->panel_size_float = AUOK190X_VERSION_SIZE_FLOAT(data[2]);
  	par->panel_model = AUOK190X_VERSION_MODEL(data[2]);
  
  	par->tcon_version = AUOK190X_VERSION_TCON(data[3]);
  	par->lut_version = AUOK190X_VERSION_LUT(data[3]);
  
  	dev_dbg(dev, "panel %d.%din, model 0x%x, EPD 0x%x TCON-rev 0x%x, LUT-rev 0x%x",
  		par->panel_size_int, par->panel_size_float, par->panel_model,
  		par->epd_type, par->tcon_version, par->lut_version);
  
  	pm_runtime_mark_last_busy(dev);
  	pm_runtime_put_autosuspend(dev);
  }
  
  /*
   * Sysfs functions
   */
  
  static ssize_t update_mode_show(struct device *dev,
  				struct device_attribute *attr, char *buf)
  {
  	struct fb_info *info = dev_get_drvdata(dev);
  	struct auok190xfb_par *par = info->par;
  
  	return sprintf(buf, "%d
  ", par->update_mode);
  }
  
  static ssize_t update_mode_store(struct device *dev,
  				 struct device_attribute *attr,
  				 const char *buf, size_t count)
  {
  	struct fb_info *info = dev_get_drvdata(dev);
  	struct auok190xfb_par *par = info->par;
  	int mode, ret;
  
  	ret = kstrtoint(buf, 10, &mode);
  	if (ret)
  		return ret;
  
  	par->update_mode = mode;
  
  	/* if we enter a better mode, do a full update */
  	if (par->last_mode > 1 && mode < par->last_mode)
  		par->update_all(par);
  
  	return count;
  }
  
  static ssize_t flash_show(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	struct fb_info *info = dev_get_drvdata(dev);
  	struct auok190xfb_par *par = info->par;
  
  	return sprintf(buf, "%d
  ", par->flash);
  }
  
  static ssize_t flash_store(struct device *dev, struct device_attribute *attr,
  			   const char *buf, size_t count)
  {
  	struct fb_info *info = dev_get_drvdata(dev);
  	struct auok190xfb_par *par = info->par;
  	int flash, ret;
  
  	ret = kstrtoint(buf, 10, &flash);
  	if (ret)
  		return ret;
  
  	if (flash > 0)
  		par->flash = 1;
  	else
  		par->flash = 0;
  
  	return count;
  }
  
  static ssize_t temp_show(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct fb_info *info = dev_get_drvdata(dev);
  	struct auok190xfb_par *par = info->par;
  	int temp;
  
  	temp = auok190x_read_temperature(par);
  	return sprintf(buf, "%d
  ", temp);
  }
  
  static DEVICE_ATTR(update_mode, 0644, update_mode_show, update_mode_store);
  static DEVICE_ATTR(flash, 0644, flash_show, flash_store);
  static DEVICE_ATTR(temp, 0644, temp_show, NULL);
  
  static struct attribute *auok190x_attributes[] = {
  	&dev_attr_update_mode.attr,
  	&dev_attr_flash.attr,
  	&dev_attr_temp.attr,
  	NULL
  };
  
  static const struct attribute_group auok190x_attr_group = {
  	.attrs		= auok190x_attributes,
  };
  
  static int auok190x_power(struct auok190xfb_par *par, bool on)
  {
  	struct auok190x_board *board = par->board;
  	int ret;
  
  	if (on) {
  		/* We should maintain POWER up for at least 80ms before set
  		 * RST_N and SLP_N to high (TCON spec 20100803_v35 p59)
  		 */
  		ret = regulator_enable(par->regulator);
  		if (ret)
  			return ret;
  
  		msleep(200);
  		gpio_set_value(board->gpio_nrst, 1);
  		gpio_set_value(board->gpio_nsleep, 1);
  		msleep(200);
  	} else {
  		regulator_disable(par->regulator);
  		gpio_set_value(board->gpio_nrst, 0);
  		gpio_set_value(board->gpio_nsleep, 0);
  	}
  
  	return 0;
  }
  
  /*
   * Recovery - powercycle the controller
   */
  
  static void auok190x_recover(struct auok190xfb_par *par)
  {
  	struct device *dev = par->info->device;
  
  	auok190x_power(par, 0);
  	msleep(100);
  	auok190x_power(par, 1);
  
  	/* after powercycling the device, it's always active */
  	pm_runtime_set_active(dev);
  	par->standby = 0;
  
  	par->init(par);
  
  	/* wait for init to complete */
  	par->board->wait_for_rdy(par);
  }
  
  /*
   * Power-management
   */
  
  #ifdef CONFIG_PM
  static int auok190x_runtime_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct fb_info *info = platform_get_drvdata(pdev);
  	struct auok190xfb_par *par = info->par;
  	struct auok190x_board *board = par->board;
  	u16 standby_param;
  
  	/* take and keep the lock until we are resumed, as the controller
  	 * will never reach the non-busy state when in standby mode
  	 */
  	mutex_lock(&(par->io_lock));
  
  	if (par->standby) {
  		dev_warn(dev, "already in standby, runtime-pm pairing mismatch
  ");
  		mutex_unlock(&(par->io_lock));
  		return 0;
  	}
  
  	/* according to runtime_pm.txt runtime_suspend only means, that the
  	 * device will not process data and will not communicate with the CPU
  	 * As we hold the lock, this stays true even without standby
  	 */
  	if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
  		dev_dbg(dev, "runtime suspend without standby
  ");
  		goto finish;
  	} else if (board->quirks & AUOK190X_QUIRK_STANDBYPARAM) {
  		/* for some TCON versions STANDBY expects a parameter (0) but
  		 * it seems the real tcon version has to be determined yet.
  		 */
  		dev_dbg(dev, "runtime suspend with additional empty param
  ");
  		standby_param = 0;
  		auok190x_send_cmdargs(par, AUOK190X_CMD_STANDBY, 1,
  				      &standby_param);
  	} else {
  		dev_dbg(dev, "runtime suspend without param
  ");
  		auok190x_send_command(par, AUOK190X_CMD_STANDBY);
  	}
  
  	msleep(64);
  
  finish:
  	par->standby = 1;
  
  	return 0;
  }
  
  static int auok190x_runtime_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct fb_info *info = platform_get_drvdata(pdev);
  	struct auok190xfb_par *par = info->par;
  	struct auok190x_board *board = par->board;
  
  	if (!par->standby) {
  		dev_warn(dev, "not in standby, runtime-pm pairing mismatch
  ");
  		return 0;
  	}
  
  	if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
  		dev_dbg(dev, "runtime resume without standby
  ");
  	} else {
  		/* when in standby, controller is always busy
  		 * and only accepts the wakeup command
  		 */
  		dev_dbg(dev, "runtime resume from standby
  ");
  		auok190x_send_command_nowait(par, AUOK190X_CMD_WAKEUP);
  
  		msleep(160);
  
  		/* wait for the controller to be ready and release the lock */
  		board->wait_for_rdy(par);
  	}
  
  	par->standby = 0;
  
  	mutex_unlock(&(par->io_lock));
  
  	return 0;
  }
  
  static int auok190x_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct fb_info *info = platform_get_drvdata(pdev);
  	struct auok190xfb_par *par = info->par;
  	struct auok190x_board *board = par->board;
  	int ret;
  
  	dev_dbg(dev, "suspend
  ");
  	if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
  		/* suspend via powering off the ic */
  		dev_dbg(dev, "suspend with broken standby
  ");
  
  		auok190x_power(par, 0);
  	} else {
  		dev_dbg(dev, "suspend using sleep
  ");
  
  		/* the sleep state can only be entered from the standby state.
  		 * pm_runtime_get_noresume gets called before the suspend call.
  		 * So the devices usage count is >0 but it is not necessarily
  		 * active.
  		 */
  		if (!pm_runtime_status_suspended(dev)) {
  			ret = auok190x_runtime_suspend(dev);
  			if (ret < 0) {
  				dev_err(dev, "auok190x_runtime_suspend failed with %d
  ",
  					ret);
  				return ret;
  			}
  			par->manual_standby = 1;
  		}
  
  		gpio_direction_output(board->gpio_nsleep, 0);
  	}
  
  	msleep(100);
  
  	return 0;
  }
  
  static int auok190x_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct fb_info *info = platform_get_drvdata(pdev);
  	struct auok190xfb_par *par = info->par;
  	struct auok190x_board *board = par->board;
  
  	dev_dbg(dev, "resume
  ");
  	if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
  		dev_dbg(dev, "resume with broken standby
  ");
  
  		auok190x_power(par, 1);
  
  		par->init(par);
  	} else {
  		dev_dbg(dev, "resume from sleep
  ");
  
  		/* device should be in runtime suspend when we were suspended
  		 * and pm_runtime_put_sync gets called after this function.
  		 * So there is no need to touch the standby mode here at all.
  		 */
  		gpio_direction_output(board->gpio_nsleep, 1);
  		msleep(100);
  
  		/* an additional init call seems to be necessary after sleep */
  		auok190x_runtime_resume(dev);
  		par->init(par);
  
  		/* if we were runtime-suspended before, suspend again*/
  		if (!par->manual_standby)
  			auok190x_runtime_suspend(dev);
  		else
  			par->manual_standby = 0;
  	}
  
  	return 0;
  }
  #endif
  
  const struct dev_pm_ops auok190x_pm = {
  	SET_RUNTIME_PM_OPS(auok190x_runtime_suspend, auok190x_runtime_resume,
  			   NULL)
  	SET_SYSTEM_SLEEP_PM_OPS(auok190x_suspend, auok190x_resume)
  };
  EXPORT_SYMBOL_GPL(auok190x_pm);
  
  /*
   * Common probe and remove code
   */
  
  int auok190x_common_probe(struct platform_device *pdev,
  			  struct auok190x_init_data *init)
  {
  	struct auok190x_board *board = init->board;
  	struct auok190xfb_par *par;
  	struct fb_info *info;
  	struct panel_info *panel;
  	int videomemorysize, ret;
  	unsigned char *videomemory;
  
  	/* check board contents */
  	if (!board->init || !board->cleanup || !board->wait_for_rdy
  	    || !board->set_ctl || !board->set_hdb || !board->get_hdb
  	    || !board->setup_irq)
  		return -EINVAL;
  
  	info = framebuffer_alloc(sizeof(struct auok190xfb_par), &pdev->dev);
  	if (!info)
  		return -ENOMEM;
  
  	par = info->par;
  	par->info = info;
  	par->board = board;
  	par->recover = auok190x_recover;
  	par->update_partial = init->update_partial;
  	par->update_all = init->update_all;
  	par->need_refresh = init->need_refresh;
  	par->init = init->init;
  
  	/* init update modes */
  	par->update_cnt = 0;
  	par->update_mode = -1;
  	par->last_mode = -1;
  	par->flash = 0;
  
  	par->regulator = regulator_get(info->device, "vdd");
  	if (IS_ERR(par->regulator)) {
  		ret = PTR_ERR(par->regulator);
  		dev_err(info->device, "Failed to get regulator: %d
  ", ret);
  		goto err_reg;
  	}
  
  	ret = board->init(par);
  	if (ret) {
  		dev_err(info->device, "board init failed, %d
  ", ret);
  		goto err_board;
  	}
  
  	ret = gpio_request(board->gpio_nsleep, "AUOK190x sleep");
  	if (ret) {
  		dev_err(info->device, "could not request sleep gpio, %d
  ",
  			ret);
  		goto err_gpio1;
  	}
  
  	ret = gpio_direction_output(board->gpio_nsleep, 0);
  	if (ret) {
  		dev_err(info->device, "could not set sleep gpio, %d
  ", ret);
  		goto err_gpio2;
  	}
  
  	ret = gpio_request(board->gpio_nrst, "AUOK190x reset");
  	if (ret) {
  		dev_err(info->device, "could not request reset gpio, %d
  ",
  			ret);
  		goto err_gpio2;
  	}
  
  	ret = gpio_direction_output(board->gpio_nrst, 0);
  	if (ret) {
  		dev_err(info->device, "could not set reset gpio, %d
  ", ret);
  		goto err_gpio3;
  	}
  
  	ret = auok190x_power(par, 1);
  	if (ret) {
  		dev_err(info->device, "could not power on the device, %d
  ",
  			ret);
  		goto err_gpio3;
  	}
  
  	mutex_init(&par->io_lock);
  
  	init_waitqueue_head(&par->waitq);
  
  	ret = par->board->setup_irq(par->info);
  	if (ret) {
  		dev_err(info->device, "could not setup ready-irq, %d
  ", ret);
  		goto err_irq;
  	}
  
  	/* wait for init to complete */
  	par->board->wait_for_rdy(par);
  
  	/*
  	 * From here on the controller can talk to us
  	 */
  
  	/* initialise fix, var, resolution and rotation */
  
  	strlcpy(info->fix.id, init->id, 16);
  	info->var.bits_per_pixel = 8;
  	info->var.grayscale = 1;
  
  	panel = &panel_table[board->resolution];
  
  	par->resolution = board->resolution;
  	par->rotation = 0;
  
  	/* videomemory handling */
  
  	videomemorysize = roundup((panel->w * panel->h) * 2, PAGE_SIZE);
  	videomemory = vmalloc(videomemorysize);
  	if (!videomemory) {
  		ret = -ENOMEM;
  		goto err_irq;
  	}
  
  	memset(videomemory, 0, videomemorysize);
  	info->screen_base = (char *)videomemory;
  	info->fix.smem_len = videomemorysize;
  
  	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
  	info->fbops = &auok190xfb_ops;
  
  	ret = auok190xfb_check_var(&info->var, info);
  	if (ret)
  		goto err_defio;
  
  	auok190xfb_set_fix(info);
  
  	/* deferred io init */
  
  	info->fbdefio = devm_kzalloc(info->device,
  				     sizeof(struct fb_deferred_io),
  				     GFP_KERNEL);
  	if (!info->fbdefio) {
  		dev_err(info->device, "Failed to allocate memory
  ");
  		ret = -ENOMEM;
  		goto err_defio;
  	}
  
  	dev_dbg(info->device, "targeting %d frames per second
  ", board->fps);
  	info->fbdefio->delay = HZ / board->fps;
  	info->fbdefio->first_io = auok190xfb_dpy_first_io,
  	info->fbdefio->deferred_io = auok190xfb_dpy_deferred_io,
  	fb_deferred_io_init(info);
  
  	/* color map */
  
  	ret = fb_alloc_cmap(&info->cmap, 256, 0);
  	if (ret < 0) {
  		dev_err(info->device, "Failed to allocate colormap
  ");
  		goto err_cmap;
  	}
  
  	/* controller init */
  
  	par->consecutive_threshold = 100;
  	par->init(par);
  	auok190x_identify(par);
  
  	platform_set_drvdata(pdev, info);
  
  	ret = register_framebuffer(info);
  	if (ret < 0)
  		goto err_regfb;
  
  	ret = sysfs_create_group(&info->device->kobj, &auok190x_attr_group);
  	if (ret)
  		goto err_sysfs;
  
  	dev_info(info->device, "fb%d: %dx%d using %dK of video memory
  ",
  		 info->node, info->var.xres, info->var.yres,
  		 videomemorysize >> 10);
  
  	/* increase autosuspend_delay when we use alternative methods
  	 * for runtime_pm
  	 */
  	par->autosuspend_delay = (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN)
  					? 1000 : 200;
  
  	pm_runtime_set_active(info->device);
  	pm_runtime_enable(info->device);
  	pm_runtime_set_autosuspend_delay(info->device, par->autosuspend_delay);
  	pm_runtime_use_autosuspend(info->device);
  
  	return 0;
  
  err_sysfs:
  	unregister_framebuffer(info);
  err_regfb:
  	fb_dealloc_cmap(&info->cmap);
  err_cmap:
  	fb_deferred_io_cleanup(info);
  err_defio:
  	vfree((void *)info->screen_base);
  err_irq:
  	auok190x_power(par, 0);
  err_gpio3:
  	gpio_free(board->gpio_nrst);
  err_gpio2:
  	gpio_free(board->gpio_nsleep);
  err_gpio1:
  	board->cleanup(par);
  err_board:
  	regulator_put(par->regulator);
  err_reg:
  	framebuffer_release(info);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(auok190x_common_probe);
  
  int  auok190x_common_remove(struct platform_device *pdev)
  {
  	struct fb_info *info = platform_get_drvdata(pdev);
  	struct auok190xfb_par *par = info->par;
  	struct auok190x_board *board = par->board;
  
  	pm_runtime_disable(info->device);
  
  	sysfs_remove_group(&info->device->kobj, &auok190x_attr_group);
  
  	unregister_framebuffer(info);
  
  	fb_dealloc_cmap(&info->cmap);
  
  	fb_deferred_io_cleanup(info);
  
  	vfree((void *)info->screen_base);
  
  	auok190x_power(par, 0);
  
  	gpio_free(board->gpio_nrst);
  	gpio_free(board->gpio_nsleep);
  
  	board->cleanup(par);
  
  	regulator_put(par->regulator);
  
  	framebuffer_release(info);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(auok190x_common_remove);
  
  MODULE_DESCRIPTION("Common code for AUO-K190X controllers");
  MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
  MODULE_LICENSE("GPL");