xref: /linux/drivers/video/fbdev/core/fbmem.c (revision 2ed2e359dea752e7758d29a423033031a0b96584)

/*
 *  linux/drivers/video/fbmem.c
 *
 *  Copyright (C) 1994 Martin Schaller
 *
 *	2001 - Documented with DocBook
 *	- Brad Douglas <brad@neruo.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/console.h>
#include <linux/export.h>
#include <linux/fb.h>
#include <linux/lcd.h>
#include <linux/leds.h>

#include <video/nomodeset.h>

#include "fb_internal.h"
#include "fbcon.h"

    /*
     *  Frame buffer device initialization and setup routines
     */

#define FBPIXMAPSIZE	(1024 * 8)

struct class *fb_class;

DEFINE_MUTEX(registration_lock);
struct fb_info *registered_fb[FB_MAX] __read_mostly;
int num_registered_fb __read_mostly;
#define for_each_registered_fb(i)		\
	for (i = 0; i < FB_MAX; i++)		\
		if (!registered_fb[i]) {} else

struct fb_info *get_fb_info(unsigned int idx)
{
	struct fb_info *fb_info;

	if (idx >= FB_MAX)
		return ERR_PTR(-ENODEV);

	mutex_lock(&registration_lock);
	fb_info = registered_fb[idx];
	if (fb_info)
		refcount_inc(&fb_info->count);
	mutex_unlock(&registration_lock);

	return fb_info;
}

void put_fb_info(struct fb_info *fb_info)
{
	if (!refcount_dec_and_test(&fb_info->count))
		return;
	if (fb_info->fbops->fb_destroy)
		fb_info->fbops->fb_destroy(fb_info);
}

/*
 * Helpers
 */

int fb_get_color_depth(struct fb_var_screeninfo *var,
		       struct fb_fix_screeninfo *fix)
{
	int depth = 0;

	if (fix->visual == FB_VISUAL_MONO01 ||
	    fix->visual == FB_VISUAL_MONO10)
		depth = 1;
	else {
		if (var->green.length == var->blue.length &&
		    var->green.length == var->red.length &&
		    var->green.offset == var->blue.offset &&
		    var->green.offset == var->red.offset)
			depth = var->green.length;
		else
			depth = var->green.length + var->red.length +
				var->blue.length;
	}

	return depth;
}
EXPORT_SYMBOL(fb_get_color_depth);

/*
 * Data padding functions.
 */
void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 s_pitch, u32 height)
{
	__fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
}
EXPORT_SYMBOL(fb_pad_aligned_buffer);

void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 idx, u32 height,
			     u32 shift_high, u32 shift_low, u32 mod)
{
	u8 mask = (u8) (0xff << shift_high), tmp;
	int i, j;

	for (i = height; i--; ) {
		for (j = 0; j < idx; j++) {
			tmp = dst[j];
			tmp &= mask;
			tmp |= *src >> shift_low;
			dst[j] = tmp;
			tmp = *src << shift_high;
			dst[j+1] = tmp;
			src++;
		}
		tmp = dst[idx];
		tmp &= mask;
		tmp |= *src >> shift_low;
		dst[idx] = tmp;
		if (shift_high < mod) {
			tmp = *src << shift_high;
			dst[idx+1] = tmp;
		}
		src++;
		dst += d_pitch;
	}
}
EXPORT_SYMBOL(fb_pad_unaligned_buffer);

/*
 * we need to lock this section since fb_cursor
 * may use fb_imageblit()
 */
char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size)
{
	u32 align = buf->buf_align - 1, offset;
	char *addr = buf->addr;

	/* If IO mapped, we need to sync before access, no sharing of
	 * the pixmap is done
	 */
	if (buf->flags & FB_PIXMAP_IO) {
		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
			info->fbops->fb_sync(info);
		return addr;
	}

	/* See if we fit in the remaining pixmap space */
	offset = buf->offset + align;
	offset &= ~align;
	if (offset + size > buf->size) {
		/* We do not fit. In order to be able to re-use the buffer,
		 * we must ensure no asynchronous DMA'ing or whatever operation
		 * is in progress, we sync for that.
		 */
		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
			info->fbops->fb_sync(info);
		offset = 0;
	}
	buf->offset = offset + size;
	addr += offset;

	return addr;
}
EXPORT_SYMBOL(fb_get_buffer_offset);

int
fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var)
{
	struct fb_fix_screeninfo *fix = &info->fix;
	unsigned int yres = info->var.yres;
	int err = 0;

	if (var->yoffset > 0) {
		if (var->vmode & FB_VMODE_YWRAP) {
			if (!fix->ywrapstep || (var->yoffset % fix->ywrapstep))
				err = -EINVAL;
			else
				yres = 0;
		} else if (!fix->ypanstep || (var->yoffset % fix->ypanstep))
			err = -EINVAL;
	}

	if (var->xoffset > 0 && (!fix->xpanstep ||
				 (var->xoffset % fix->xpanstep)))
		err = -EINVAL;

	if (err || !info->fbops->fb_pan_display ||
	    var->yoffset > info->var.yres_virtual - yres ||
	    var->xoffset > info->var.xres_virtual - info->var.xres)
		return -EINVAL;

	if ((err = info->fbops->fb_pan_display(var, info)))
		return err;
	info->var.xoffset = var->xoffset;
	info->var.yoffset = var->yoffset;
	if (var->vmode & FB_VMODE_YWRAP)
		info->var.vmode |= FB_VMODE_YWRAP;
	else
		info->var.vmode &= ~FB_VMODE_YWRAP;
	return 0;
}
EXPORT_SYMBOL(fb_pan_display);

static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
			 u32 activate)
{
	struct fb_blit_caps caps, fbcaps;
	int err = 0;

	memset(&caps, 0, sizeof(caps));
	memset(&fbcaps, 0, sizeof(fbcaps));
	caps.flags = (activate & FB_ACTIVATE_ALL) ? 1 : 0;
	fbcon_get_requirement(info, &caps);
	info->fbops->fb_get_caps(info, &fbcaps, var);

	if (!bitmap_subset(caps.x, fbcaps.x, FB_MAX_BLIT_WIDTH) ||
	    !bitmap_subset(caps.y, fbcaps.y, FB_MAX_BLIT_HEIGHT) ||
	    (fbcaps.len < caps.len))
		err = -EINVAL;

	return err;
}

static void fb_lcd_notify_mode_change(struct fb_info *info,
				      struct fb_videomode *mode)
{
	lcd_notify_mode_change_all(info->device, mode->xres, mode->yres);
}

int
fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
{
	int ret = 0;
	u32 activate;
	struct fb_var_screeninfo old_var;
	struct fb_videomode mode;
	u32 unused;

	if (var->activate & FB_ACTIVATE_INV_MODE) {
		struct fb_videomode mode1, mode2;

		fb_var_to_videomode(&mode1, var);
		fb_var_to_videomode(&mode2, &info->var);
		/* make sure we don't delete the videomode of current var */
		ret = fb_mode_is_equal(&mode1, &mode2);
		if (!ret) {
			ret = fbcon_mode_deleted(info, &mode1);
			if (!ret)
				fb_delete_videomode(&mode1, &info->modelist);
		}

		return ret ? -EINVAL : 0;
	}

	if (!(var->activate & FB_ACTIVATE_FORCE) &&
	    !memcmp(&info->var, var, sizeof(struct fb_var_screeninfo)))
		return 0;

	activate = var->activate;

	/* When using FOURCC mode, make sure the red, green, blue and
	 * transp fields are set to 0.
	 */
	if ((info->fix.capabilities & FB_CAP_FOURCC) &&
	    var->grayscale > 1) {
		if (var->red.offset     || var->green.offset    ||
		    var->blue.offset    || var->transp.offset   ||
		    var->red.length     || var->green.length    ||
		    var->blue.length    || var->transp.length   ||
		    var->red.msb_right  || var->green.msb_right ||
		    var->blue.msb_right || var->transp.msb_right)
			return -EINVAL;
	}

	if (!info->fbops->fb_check_var) {
		*var = info->var;
		return 0;
	}

	/* bitfill_aligned() assumes that it's at least 8x8 */
	if (var->xres < 8 || var->yres < 8)
		return -EINVAL;

	/* Too huge resolution causes multiplication overflow. */
	if (check_mul_overflow(var->xres, var->yres, &unused) ||
	    check_mul_overflow(var->xres_virtual, var->yres_virtual, &unused))
		return -EINVAL;

	ret = info->fbops->fb_check_var(var, info);

	if (ret)
		return ret;

	/* verify that virtual resolution >= physical resolution */
	if (var->xres_virtual < var->xres ||
	    var->yres_virtual < var->yres) {
		pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",
			info->fix.id,
			var->xres_virtual, var->yres_virtual,
			var->xres, var->yres);
		return -EINVAL;
	}

	if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
		return 0;

	if (info->fbops->fb_get_caps) {
		ret = fb_check_caps(info, var, activate);

		if (ret)
			return ret;
	}

	old_var = info->var;
	info->var = *var;

	if (info->fbops->fb_set_par) {
		ret = info->fbops->fb_set_par(info);

		if (ret) {
			info->var = old_var;
			printk(KERN_WARNING "detected "
				"fb_set_par error, "
				"error code: %d\n", ret);
			return ret;
		}
	}

	fb_pan_display(info, &info->var);
	fb_set_cmap(&info->cmap, info);
	fb_var_to_videomode(&mode, &info->var);

	if (info->modelist.prev && info->modelist.next &&
	    !list_empty(&info->modelist))
		ret = fb_add_videomode(&mode, &info->modelist);

	if (ret) {
		info->var = old_var;
		return ret;
	}

	fb_lcd_notify_mode_change(info, &mode);

	return 0;
}
EXPORT_SYMBOL(fb_set_var);

int fb_set_var_from_user(struct fb_info *info, struct fb_var_screeninfo *var)
{
	int ret = fbcon_modechange_possible(info, var);

	if (!ret)
		ret = fb_set_var(info, var);
	if (!ret)
		fbcon_update_vcs(info, var->activate & FB_ACTIVATE_ALL);

	return ret;
}
EXPORT_SYMBOL(fb_set_var_from_user);

static void fb_lcd_notify_blank(struct fb_info *info)
{
	int power;

	switch (info->blank) {
	case FB_BLANK_UNBLANK:
		power = LCD_POWER_ON;
		break;
	/* deprecated; TODO: should become 'off' */
	case FB_BLANK_NORMAL:
		power = LCD_POWER_REDUCED;
		break;
	case FB_BLANK_VSYNC_SUSPEND:
		power = LCD_POWER_REDUCED_VSYNC_SUSPEND;
		break;
	/* 'off' */
	case FB_BLANK_HSYNC_SUSPEND:
	case FB_BLANK_POWERDOWN:
	default:
		power = LCD_POWER_OFF;
		break;
	}

	lcd_notify_blank_all(info->device, power);
}

static void fb_ledtrig_backlight_notify_blank(struct fb_info *info)
{
	if (info->blank == FB_BLANK_UNBLANK)
		ledtrig_backlight_blank(false);
	else
		ledtrig_backlight_blank(true);
}

int fb_blank(struct fb_info *info, int blank)
{
	int old_blank = info->blank;
	int ret;

	if (!info->fbops->fb_blank)
		return -EINVAL;

	if (blank > FB_BLANK_POWERDOWN)
		blank = FB_BLANK_POWERDOWN;

	info->blank = blank;

	ret = info->fbops->fb_blank(blank, info);
	if (ret)
		goto err;

	fb_bl_notify_blank(info, old_blank);
	fb_lcd_notify_blank(info);
	fb_ledtrig_backlight_notify_blank(info);

	return 0;

err:
	info->blank = old_blank;
	return ret;
}
EXPORT_SYMBOL(fb_blank);

int fb_blank_from_user(struct fb_info *info, int blank)
{
	int ret = fb_blank(info, blank);

	/* might again call into fb_blank */
	fbcon_fb_blanked(info, blank);

	return ret;
}

static int fb_check_foreignness(struct fb_info *fi)
{
	const bool foreign_endian = fi->flags & FBINFO_FOREIGN_ENDIAN;

	fi->flags &= ~FBINFO_FOREIGN_ENDIAN;

#ifdef __BIG_ENDIAN
	fi->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
#else
	fi->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
#endif /* __BIG_ENDIAN */

	if (fi->flags & FBINFO_BE_MATH && !fb_be_math(fi)) {
		pr_err("%s: enable CONFIG_FB_BIG_ENDIAN to "
		       "support this framebuffer\n", fi->fix.id);
		return -ENOSYS;
	} else if (!(fi->flags & FBINFO_BE_MATH) && fb_be_math(fi)) {
		pr_err("%s: enable CONFIG_FB_LITTLE_ENDIAN to "
		       "support this framebuffer\n", fi->fix.id);
		return -ENOSYS;
	}

	return 0;
}

static int do_register_framebuffer(struct fb_info *fb_info)
{
	int i, err = 0;
	struct fb_videomode mode;

	if (fb_check_foreignness(fb_info))
		return -ENOSYS;

	if (num_registered_fb == FB_MAX)
		return -ENXIO;

	for (i = 0 ; i < FB_MAX; i++)
		if (!registered_fb[i])
			break;

	if (i >= FB_MAX)
		return -ENXIO;

	if (!fb_info->modelist.prev || !fb_info->modelist.next)
		INIT_LIST_HEAD(&fb_info->modelist);

	fb_var_to_videomode(&mode, &fb_info->var);
	err = fb_add_videomode(&mode, &fb_info->modelist);
	if (err < 0)
		return err;

	fb_info->node = i;
	refcount_set(&fb_info->count, 1);
	mutex_init(&fb_info->lock);
	mutex_init(&fb_info->mm_lock);

	/*
	 * With an fb_blank callback present, we assume that the
	 * display is blank, so that fb_blank() enables it on the
	 * first modeset.
	 */
	if (fb_info->fbops->fb_blank)
		fb_info->blank = FB_BLANK_POWERDOWN;

	fb_device_create(fb_info);

	if (fb_info->pixmap.addr == NULL) {
		fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
		if (fb_info->pixmap.addr) {
			fb_info->pixmap.size = FBPIXMAPSIZE;
			fb_info->pixmap.buf_align = 1;
			fb_info->pixmap.scan_align = 1;
			fb_info->pixmap.access_align = 32;
			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
		}
	}
	fb_info->pixmap.offset = 0;

	if (bitmap_empty(fb_info->pixmap.blit_x, FB_MAX_BLIT_WIDTH))
		bitmap_fill(fb_info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);

	if (bitmap_empty(fb_info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT))
		bitmap_fill(fb_info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT);

	if (fb_info->skip_vt_switch)
		pm_vt_switch_required(fb_info->device, false);
	else
		pm_vt_switch_required(fb_info->device, true);

	num_registered_fb++;
	registered_fb[i] = fb_info;

#ifdef CONFIG_GUMSTIX_AM200EPD
	{
		struct fb_event event;
		event.info = fb_info;
		fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
	}
#endif

	return fbcon_fb_registered(fb_info);
}

static void unbind_console(struct fb_info *fb_info)
{
	int i = fb_info->node;

	if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
		return;

	fbcon_fb_unbind(fb_info);
}

static void unlink_framebuffer(struct fb_info *fb_info)
{
	int i;

	i = fb_info->node;
	if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
		return;

	fb_device_destroy(fb_info);
	pm_vt_switch_unregister(fb_info->device);
	unbind_console(fb_info);
}

static void do_unregister_framebuffer(struct fb_info *fb_info)
{
	unlink_framebuffer(fb_info);
	if (fb_info->pixmap.addr &&
	    (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) {
		kfree(fb_info->pixmap.addr);
		fb_info->pixmap.addr = NULL;
	}

	fbcon_delete_modelist(&fb_info->modelist);
	fb_destroy_modelist(&fb_info->modelist);
	registered_fb[fb_info->node] = NULL;
	num_registered_fb--;
#ifdef CONFIG_GUMSTIX_AM200EPD
	{
		struct fb_event event;
		event.info = fb_info;
		fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
	}
#endif
	fbcon_fb_unregistered(fb_info);

	/* this may free fb info */
	put_fb_info(fb_info);
}

/**
 *	register_framebuffer - registers a frame buffer device
 *	@fb_info: frame buffer info structure
 *
 *	Registers a frame buffer device @fb_info.
 *
 *	Returns negative errno on error, or zero for success.
 *
 */
int
register_framebuffer(struct fb_info *fb_info)
{
	int ret;

	mutex_lock(&registration_lock);
	ret = do_register_framebuffer(fb_info);
	mutex_unlock(&registration_lock);

	return ret;
}
EXPORT_SYMBOL(register_framebuffer);

/**
 *	unregister_framebuffer - releases a frame buffer device
 *	@fb_info: frame buffer info structure
 *
 *	Unregisters a frame buffer device @fb_info.
 *
 *	Returns negative errno on error, or zero for success.
 *
 *      This function will also notify the framebuffer console
 *      to release the driver.
 *
 *      This is meant to be called within a driver's module_exit()
 *      function. If this is called outside module_exit(), ensure
 *      that the driver implements fb_open() and fb_release() to
 *      check that no processes are using the device.
 */
void
unregister_framebuffer(struct fb_info *fb_info)
{
	mutex_lock(&registration_lock);
	do_unregister_framebuffer(fb_info);
	mutex_unlock(&registration_lock);
}
EXPORT_SYMBOL(unregister_framebuffer);

static void devm_unregister_framebuffer(void *data)
{
	struct fb_info *info = data;

	unregister_framebuffer(info);
}

/**
 *	devm_register_framebuffer - resource-managed frame buffer device registration
 *	@dev: device the framebuffer belongs to
 *	@fb_info: frame buffer info structure
 *
 *	Registers a frame buffer device @fb_info to device @dev.
 *
 *	Returns negative errno on error, or zero for success.
 *
 */
int
devm_register_framebuffer(struct device *dev, struct fb_info *fb_info)
{
	int ret;

	ret = register_framebuffer(fb_info);
	if (ret)
		return ret;

	return devm_add_action_or_reset(dev, devm_unregister_framebuffer, fb_info);
}
EXPORT_SYMBOL(devm_register_framebuffer);

/**
 *	fb_set_suspend - low level driver signals suspend
 *	@info: framebuffer affected
 *	@state: 0 = resuming, !=0 = suspending
 *
 *	This is meant to be used by low level drivers to
 * 	signal suspend/resume to the core & clients.
 *	It must be called with the console semaphore held
 */
void fb_set_suspend(struct fb_info *info, int state)
{
	WARN_CONSOLE_UNLOCKED();

	if (state) {
		fbcon_suspended(info);
		info->state = FBINFO_STATE_SUSPENDED;
	} else {
		info->state = FBINFO_STATE_RUNNING;
		fbcon_resumed(info);
	}
}
EXPORT_SYMBOL(fb_set_suspend);

/**
 * fb_switch_outputs - framebuffer got the outputs from vga-switcheroo
 * @info: framebuffer
 */
void fb_switch_outputs(struct fb_info *info)
{
	fbcon_remap_all(info);
}
EXPORT_SYMBOL(fb_switch_outputs);

static int __init fbmem_init(void)
{
	int ret;

	fb_class = class_create("graphics");
	if (IS_ERR(fb_class)) {
		ret = PTR_ERR(fb_class);
		pr_err("Unable to create fb class; errno = %d\n", ret);
		goto err_fb_class;
	}

	ret = fb_init_procfs();
	if (ret)
		goto err_class_destroy;

	ret = fb_register_chrdev();
	if (ret)
		goto err_fb_cleanup_procfs;

	fb_console_init();

	return 0;

err_fb_cleanup_procfs:
	fb_cleanup_procfs();
err_class_destroy:
	class_destroy(fb_class);
err_fb_class:
	fb_class = NULL;
	return ret;
}

#ifdef MODULE
static void __exit fbmem_exit(void)
{
	fb_console_exit();
	fb_unregister_chrdev();
	fb_cleanup_procfs();
	class_destroy(fb_class);
}

module_init(fbmem_init);
module_exit(fbmem_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Framebuffer base");
#else
subsys_initcall(fbmem_init);
#endif

int fb_new_modelist(struct fb_info *info)
{
	struct fb_var_screeninfo var = info->var;
	struct list_head *pos, *n;
	struct fb_modelist *modelist;
	struct fb_videomode *m, mode;
	int err;

	list_for_each_safe(pos, n, &info->modelist) {
		modelist = list_entry(pos, struct fb_modelist, list);
		m = &modelist->mode;
		fb_videomode_to_var(&var, m);
		var.activate = FB_ACTIVATE_TEST;
		err = fb_set_var(info, &var);
		fb_var_to_videomode(&mode, &var);
		if (err || !fb_mode_is_equal(m, &mode)) {
			list_del(pos);
			kfree(pos);
		}
	}

	if (list_empty(&info->modelist))
		return 1;

	/*
	 * The new modelist may not contain the current mode (info->var), and
	 * fbcon_new_modelist() below only re-points consoles mapped to this
	 * framebuffer. Add the current mode here so info->var keeps a match
	 * even when fbcon is unbound.
	 */
	if (!fb_match_mode(&info->var, &info->modelist)) {
		fb_var_to_videomode(&mode, &info->var);
		if (fb_add_videomode(&mode, &info->modelist))
			return 1;
	}

	fbcon_new_modelist(info);

	return 0;
}

bool fb_modesetting_disabled(const char *drvname)
{
	bool fwonly = video_firmware_drivers_only();

	if (fwonly)
		pr_warn("Driver %s not loading because of nomodeset parameter\n",
			drvname);

	return fwonly;
}
EXPORT_SYMBOL(fb_modesetting_disabled);

MODULE_LICENSE("GPL");