fbsysfs.c

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/*
 * fbsysfs.c - framebuffer device class and attributes
 *
 * Copyright (c) 2004 James Simmons <[email protected]>
 * 
 *  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

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);

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\n",
                    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();
    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);

    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\n", 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\n", 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\n", 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\n", 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\n", 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\n", 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);

    if (!lock_fb_info(fb_info))
        return -ENODEV;
    console_lock();
    fb_set_suspend(fb_info, (int)state);
    console_unlock();
    unlock_fb_info(fb_info);

    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\n", 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\n",
            &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\n",
                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