/*
   * fbsysfs.c - framebuffer device class and attributes
   *
   * Copyright (c) 2004 James Simmons <jsimmons@infradead.org>
   * 
   *	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.
   */
  
  /*
   * Note:  currently there's only stubs for framebuffer_alloc and
   * framebuffer_release here.  The reson for that is that until all drivers
   * are converted to use it a sysfsification will open OOPSable races.
   */
  
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/fb.h>
  #include <linux/console.h>
  #include <linux/module.h>
  
  #define FB_SYSFS_FLAG_ATTR 1
  
  /**
   * framebuffer_alloc - creates a new frame buffer info structure
   *
   * @size: size of driver private data, can be zero
   * @dev: pointer to the device for this fb, this can be NULL
   *
   * Creates a new frame buffer info structure. Also reserves @size bytes
   * for driver private data (info->par). info->par (if any) will be
   * aligned to sizeof(long).
   *
   * Returns the new structure, or NULL if an error occurred.
   *
   */
  struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
  {
  #define BYTES_PER_LONG (BITS_PER_LONG/8)
  #define PADDING (BYTES_PER_LONG - (sizeof(struct fb_info) % BYTES_PER_LONG))
  	int fb_info_size = sizeof(struct fb_info);
  	struct fb_info *info;
  	char *p;
  
  	if (size)
  		fb_info_size += PADDING;
  
  	p = kzalloc(fb_info_size + size, GFP_KERNEL);
  
  	if (!p)
  		return NULL;
  
  	info = (struct fb_info *) p;
  
  	if (size)
  		info->par = p + fb_info_size;
  
  	info->device = dev;
  
  #ifdef CONFIG_FB_BACKLIGHT
  	mutex_init(&info->bl_curve_mutex);
  #endif
  
  	return info;
  #undef PADDING
  #undef BYTES_PER_LONG
  }
  EXPORT_SYMBOL(framebuffer_alloc);
  
  /**
   * framebuffer_release - marks the structure available for freeing
   *
   * @info: frame buffer info structure
   *
   * Drop the reference count of the device embedded in the
   * framebuffer info structure.
   *
   */
  void framebuffer_release(struct fb_info *info)
  {
  	if (!info)
  		return;
  	kfree(info->apertures);
  	kfree(info);
  }
  EXPORT_SYMBOL(framebuffer_release);
  
  static int activate(struct fb_info *fb_info, struct fb_var_screeninfo *var)
  {
  	int err;
  
  	var->activate |= FB_ACTIVATE_FORCE;
  	console_lock();
  	fb_info->flags |= FBINFO_MISC_USEREVENT;
  	err = fb_set_var(fb_info, var);
  	fb_info->flags &= ~FBINFO_MISC_USEREVENT;
  	console_unlock();
  	if (err)
  		return err;
  	return 0;
  }
  
  static int mode_string(char *buf, unsigned int offset,
  		       const struct fb_videomode *mode)
  {
  	char m = 'U';
  	char v = 'p';
  
  	if (mode->flag & FB_MODE_IS_DETAILED)
  		m = 'D';
  	if (mode->flag & FB_MODE_IS_VESA)
  		m = 'V';
  	if (mode->flag & FB_MODE_IS_STANDARD)
  		m = 'S';
  
  	if (mode->vmode & FB_VMODE_INTERLACED)
  		v = 'i';
  	if (mode->vmode & FB_VMODE_DOUBLE)
  		v = 'd';
  
  	return snprintf(&buf[offset], PAGE_SIZE - offset, "%c:%dx%d%c-%d
  ",
  	                m, mode->xres, mode->yres, v, mode->refresh);
  }
  
  static ssize_t store_mode(struct device *device, struct device_attribute *attr,
  			  const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	char mstr[100];
  	struct fb_var_screeninfo var;
  	struct fb_modelist *modelist;
  	struct fb_videomode *mode;
  	struct list_head *pos;
  	size_t i;
  	int err;
  
  	memset(&var, 0, sizeof(var));
  
  	list_for_each(pos, &fb_info->modelist) {
  		modelist = list_entry(pos, struct fb_modelist, list);
  		mode = &modelist->mode;
  		i = mode_string(mstr, 0, mode);
  		if (strncmp(mstr, buf, max(count, i)) == 0) {
  
  			var = fb_info->var;
  			fb_videomode_to_var(&var, mode);
  			if ((err = activate(fb_info, &var)))
  				return err;
  			fb_info->mode = mode;
  			return count;
  		}
  	}
  	return -EINVAL;
  }
  
  static ssize_t show_mode(struct device *device, struct device_attribute *attr,
  			 char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  
  	if (!fb_info->mode)
  		return 0;
  
  	return mode_string(buf, 0, fb_info->mode);
  }
  
  static ssize_t store_modes(struct device *device,
  			   struct device_attribute *attr,
  			   const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	LIST_HEAD(old_list);
  	int i = count / sizeof(struct fb_videomode);
  
  	if (i * sizeof(struct fb_videomode) != count)
  		return -EINVAL;
  
  	console_lock();
  	if (!lock_fb_info(fb_info)) {
  		console_unlock();
  		return -ENODEV;
  	}
  
  	list_splice(&fb_info->modelist, &old_list);
  	fb_videomode_to_modelist((const struct fb_videomode *)buf, i,
  				 &fb_info->modelist);
  	if (fb_new_modelist(fb_info)) {
  		fb_destroy_modelist(&fb_info->modelist);
  		list_splice(&old_list, &fb_info->modelist);
  	} else
  		fb_destroy_modelist(&old_list);
  
  	unlock_fb_info(fb_info);
  	console_unlock();
  
  	return 0;
  }
  
  static ssize_t show_modes(struct device *device, struct device_attribute *attr,
  			  char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	unsigned int i;
  	struct list_head *pos;
  	struct fb_modelist *modelist;
  	const struct fb_videomode *mode;
  
  	i = 0;
  	list_for_each(pos, &fb_info->modelist) {
  		modelist = list_entry(pos, struct fb_modelist, list);
  		mode = &modelist->mode;
  		i += mode_string(buf, i, mode);
  	}
  	return i;
  }
  
  static ssize_t store_bpp(struct device *device, struct device_attribute *attr,
  			 const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	struct fb_var_screeninfo var;
  	char ** last = NULL;
  	int err;
  
  	var = fb_info->var;
  	var.bits_per_pixel = simple_strtoul(buf, last, 0);
  	if ((err = activate(fb_info, &var)))
  		return err;
  	return count;
  }
  
  static ssize_t show_bpp(struct device *device, struct device_attribute *attr,
  			char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	return snprintf(buf, PAGE_SIZE, "%d
  ", fb_info->var.bits_per_pixel);
  }
  
  static ssize_t store_rotate(struct device *device,
  			    struct device_attribute *attr,
  			    const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	struct fb_var_screeninfo var;
  	char **last = NULL;
  	int err;
  
  	var = fb_info->var;
  	var.rotate = simple_strtoul(buf, last, 0);
  
  	if ((err = activate(fb_info, &var)))
  		return err;
  
  	return count;
  }
  
  
  static ssize_t show_rotate(struct device *device,
  			   struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  
  	return snprintf(buf, PAGE_SIZE, "%d
  ", fb_info->var.rotate);
  }
  
  static ssize_t store_virtual(struct device *device,
  			     struct device_attribute *attr,
  			     const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	struct fb_var_screeninfo var;
  	char *last = NULL;
  	int err;
  
  	var = fb_info->var;
  	var.xres_virtual = simple_strtoul(buf, &last, 0);
  	last++;
  	if (last - buf >= count)
  		return -EINVAL;
  	var.yres_virtual = simple_strtoul(last, &last, 0);
  
  	if ((err = activate(fb_info, &var)))
  		return err;
  	return count;
  }
  
  static ssize_t show_virtual(struct device *device,
  			    struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	return snprintf(buf, PAGE_SIZE, "%d,%d
  ", fb_info->var.xres_virtual,
  			fb_info->var.yres_virtual);
  }
  
  static ssize_t show_stride(struct device *device,
  			   struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	return snprintf(buf, PAGE_SIZE, "%d
  ", fb_info->fix.line_length);
  }
  
  static ssize_t store_blank(struct device *device,
  			   struct device_attribute *attr,
  			   const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	char *last = NULL;
  	int err;
  
  	console_lock();
  	fb_info->flags |= FBINFO_MISC_USEREVENT;
  	err = fb_blank(fb_info, simple_strtoul(buf, &last, 0));
  	fb_info->flags &= ~FBINFO_MISC_USEREVENT;
  	console_unlock();
  	if (err < 0)
  		return err;
  	return count;
  }
  
  static ssize_t show_blank(struct device *device,
  			  struct device_attribute *attr, char *buf)
  {
  //	struct fb_info *fb_info = dev_get_drvdata(device);
  	return 0;
  }
  
  static ssize_t store_console(struct device *device,
  			     struct device_attribute *attr,
  			     const char *buf, size_t count)
  {
  //	struct fb_info *fb_info = dev_get_drvdata(device);
  	return 0;
  }
  
  static ssize_t show_console(struct device *device,
  			    struct device_attribute *attr, char *buf)
  {
  //	struct fb_info *fb_info = dev_get_drvdata(device);
  	return 0;
  }
  
  static ssize_t store_cursor(struct device *device,
  			    struct device_attribute *attr,
  			    const char *buf, size_t count)
  {
  //	struct fb_info *fb_info = dev_get_drvdata(device);
  	return 0;
  }
  
  static ssize_t show_cursor(struct device *device,
  			   struct device_attribute *attr, char *buf)
  {
  //	struct fb_info *fb_info = dev_get_drvdata(device);
  	return 0;
  }
  
  static ssize_t store_pan(struct device *device,
  			 struct device_attribute *attr,
  			 const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	struct fb_var_screeninfo var;
  	char *last = NULL;
  	int err;
  
  	var = fb_info->var;
  	var.xoffset = simple_strtoul(buf, &last, 0);
  	last++;
  	if (last - buf >= count)
  		return -EINVAL;
  	var.yoffset = simple_strtoul(last, &last, 0);
  
  	console_lock();
  	err = fb_pan_display(fb_info, &var);
  	console_unlock();
  
  	if (err < 0)
  		return err;
  	return count;
  }
  
  static ssize_t show_pan(struct device *device,
  			struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	return snprintf(buf, PAGE_SIZE, "%d,%d
  ", fb_info->var.xoffset,
  			fb_info->var.yoffset);
  }
  
  static ssize_t show_name(struct device *device,
  			 struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  
  	return snprintf(buf, PAGE_SIZE, "%s
  ", fb_info->fix.id);
  }
  
  static ssize_t store_fbstate(struct device *device,
  			     struct device_attribute *attr,
  			     const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	u32 state;
  	char *last = NULL;
  
  	state = simple_strtoul(buf, &last, 0);
  
  	console_lock();
  	if (!lock_fb_info(fb_info)) {
  		console_unlock();
  		return -ENODEV;
  	}
  
  	fb_set_suspend(fb_info, (int)state);
  
  	unlock_fb_info(fb_info);
  	console_unlock();
  
  	return count;
  }
  
  static ssize_t show_fbstate(struct device *device,
  			    struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	return snprintf(buf, PAGE_SIZE, "%d
  ", fb_info->state);
  }
  
  #ifdef CONFIG_FB_BACKLIGHT
  static ssize_t store_bl_curve(struct device *device,
  			      struct device_attribute *attr,
  			      const char *buf, size_t count)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	u8 tmp_curve[FB_BACKLIGHT_LEVELS];
  	unsigned int i;
  
  	/* Some drivers don't use framebuffer_alloc(), but those also
  	 * don't have backlights.
  	 */
  	if (!fb_info || !fb_info->bl_dev)
  		return -ENODEV;
  
  	if (count != (FB_BACKLIGHT_LEVELS / 8 * 24))
  		return -EINVAL;
  
  	for (i = 0; i < (FB_BACKLIGHT_LEVELS / 8); ++i)
  		if (sscanf(&buf[i * 24],
  			"%2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx
  ",
  			&tmp_curve[i * 8 + 0],
  			&tmp_curve[i * 8 + 1],
  			&tmp_curve[i * 8 + 2],
  			&tmp_curve[i * 8 + 3],
  			&tmp_curve[i * 8 + 4],
  			&tmp_curve[i * 8 + 5],
  			&tmp_curve[i * 8 + 6],
  			&tmp_curve[i * 8 + 7]) != 8)
  			return -EINVAL;
  
  	/* If there has been an error in the input data, we won't
  	 * reach this loop.
  	 */
  	mutex_lock(&fb_info->bl_curve_mutex);
  	for (i = 0; i < FB_BACKLIGHT_LEVELS; ++i)
  		fb_info->bl_curve[i] = tmp_curve[i];
  	mutex_unlock(&fb_info->bl_curve_mutex);
  
  	return count;
  }
  
  static ssize_t show_bl_curve(struct device *device,
  			     struct device_attribute *attr, char *buf)
  {
  	struct fb_info *fb_info = dev_get_drvdata(device);
  	ssize_t len = 0;
  	unsigned int i;
  
  	/* Some drivers don't use framebuffer_alloc(), but those also
  	 * don't have backlights.
  	 */
  	if (!fb_info || !fb_info->bl_dev)
  		return -ENODEV;
  
  	mutex_lock(&fb_info->bl_curve_mutex);
  	for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8)
  		len += snprintf(&buf[len], PAGE_SIZE,
  				"%02x %02x %02x %02x %02x %02x %02x %02x
  ",
  				fb_info->bl_curve[i + 0],
  				fb_info->bl_curve[i + 1],
  				fb_info->bl_curve[i + 2],
  				fb_info->bl_curve[i + 3],
  				fb_info->bl_curve[i + 4],
  				fb_info->bl_curve[i + 5],
  				fb_info->bl_curve[i + 6],
  				fb_info->bl_curve[i + 7]);
  	mutex_unlock(&fb_info->bl_curve_mutex);
  
  	return len;
  }
  #endif
  
  /* When cmap is added back in it should be a binary attribute
   * not a text one. Consideration should also be given to converting
   * fbdev to use configfs instead of sysfs */
  static struct device_attribute device_attrs[] = {
  	__ATTR(bits_per_pixel, S_IRUGO|S_IWUSR, show_bpp, store_bpp),
  	__ATTR(blank, S_IRUGO|S_IWUSR, show_blank, store_blank),
  	__ATTR(console, S_IRUGO|S_IWUSR, show_console, store_console),
  	__ATTR(cursor, S_IRUGO|S_IWUSR, show_cursor, store_cursor),
  	__ATTR(mode, S_IRUGO|S_IWUSR, show_mode, store_mode),
  	__ATTR(modes, S_IRUGO|S_IWUSR, show_modes, store_modes),
  	__ATTR(pan, S_IRUGO|S_IWUSR, show_pan, store_pan),
  	__ATTR(virtual_size, S_IRUGO|S_IWUSR, show_virtual, store_virtual),
  	__ATTR(name, S_IRUGO, show_name, NULL),
  	__ATTR(stride, S_IRUGO, show_stride, NULL),
  	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
  	__ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate),
  #ifdef CONFIG_FB_BACKLIGHT
  	__ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve),
  #endif
  };
  
  int fb_init_device(struct fb_info *fb_info)
  {
  	int i, error = 0;
  
  	dev_set_drvdata(fb_info->dev, fb_info);
  
  	fb_info->class_flag |= FB_SYSFS_FLAG_ATTR;
  
  	for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
  		error = device_create_file(fb_info->dev, &device_attrs[i]);
  
  		if (error)
  			break;
  	}
  
  	if (error) {
  		while (--i >= 0)
  			device_remove_file(fb_info->dev, &device_attrs[i]);
  		fb_info->class_flag &= ~FB_SYSFS_FLAG_ATTR;
  	}
  
  	return 0;
  }
  
  void fb_cleanup_device(struct fb_info *fb_info)
  {
  	unsigned int i;
  
  	if (fb_info->class_flag & FB_SYSFS_FLAG_ATTR) {
  		for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
  			device_remove_file(fb_info->dev, &device_attrs[i]);
  
  		fb_info->class_flag &= ~FB_SYSFS_FLAG_ATTR;
  	}
  }
  
  #ifdef CONFIG_FB_BACKLIGHT
  /* This function generates a linear backlight curve
   *
   *     0: off
   *   1-7: min
   * 8-127: linear from min to max
   */
  void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max)
  {
  	unsigned int i, flat, count, range = (max - min);
  
  	mutex_lock(&fb_info->bl_curve_mutex);
  
  	fb_info->bl_curve[0] = off;
  
  	for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
  		fb_info->bl_curve[flat] = min;
  
  	count = FB_BACKLIGHT_LEVELS * 15 / 16;
  	for (i = 0; i < count; ++i)
  		fb_info->bl_curve[flat + i] = min + (range * (i + 1) / count);
  
  	mutex_unlock(&fb_info->bl_curve_mutex);
  }
  EXPORT_SYMBOL_GPL(fb_bl_default_curve);
  #endif