// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * fbsysfs.c - framebuffer device class and attributes
 *
 * Copyright (c) 2004 James Simmons <jsimmons@infradead.org>
 */

#include <linux/console.h>
#include <linux/fb.h>
#include <linux/fbcon.h>
#include <linux/major.h>

#include "fb_internal.h"

static int activate(struct fb_info *fb_info, struct fb_var_screeninfo *var)
{
        int err;

        var->activate |= FB_ACTIVATE_FORCE;
        console_lock();
        lock_fb_info(fb_info);
        err = fb_set_var(fb_info, var);
        if (!err)
                fbcon_update_vcs(fb_info, var->activate & FB_ACTIVATE_ALL);
        unlock_fb_info(fb_info);
        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;
        size_t i;
        int err;

        memset(&var, 0, sizeof(var));

        list_for_each_entry(modelist, &fb_info->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();
        lock_fb_info(fb_info);

        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 fb_modelist *modelist;
        const struct fb_videomode *mode;

        i = 0;
        list_for_each_entry(modelist, &fb_info->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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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, arg;

        arg = simple_strtoul(buf, &last, 0);
        console_lock();
        err = fb_blank(fb_info, arg);
        /* might again call into fb_blank */
        fbcon_fb_blanked(fb_info, arg);
        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 sysfs_emit(buf, "%d\n", fb_info->blank);
}

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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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);

        console_lock();
        lock_fb_info(fb_info);

        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 sysfs_emit(buf, "%d\n", fb_info->state);
}

#if IS_ENABLED(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 += scnprintf(&buf[len], PAGE_SIZE - len, "%8ph\n",
                                fb_info->bl_curve + i);
        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 DEVICE_ATTR(bits_per_pixel, 0644, show_bpp, store_bpp);
static DEVICE_ATTR(blank, 0644, show_blank, store_blank);
static DEVICE_ATTR(console, 0644, show_console, store_console);
static DEVICE_ATTR(cursor, 0644, show_cursor, store_cursor);
static DEVICE_ATTR(mode, 0644, show_mode, store_mode);
static DEVICE_ATTR(modes, 0644, show_modes, store_modes);
static DEVICE_ATTR(pan, 0644, show_pan, store_pan);
static DEVICE_ATTR(virtual_size, 0644, show_virtual, store_virtual);
static DEVICE_ATTR(name, 0444, show_name, NULL);
static DEVICE_ATTR(stride, 0444, show_stride, NULL);
static DEVICE_ATTR(rotate, 0644, show_rotate, store_rotate);
static DEVICE_ATTR(state, 0644, show_fbstate, store_fbstate);
#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
static DEVICE_ATTR(bl_curve, 0644, show_bl_curve, store_bl_curve);
#endif

static struct attribute *fb_device_attrs[] = {
        &dev_attr_bits_per_pixel.attr,
        &dev_attr_blank.attr,
        &dev_attr_console.attr,
        &dev_attr_cursor.attr,
        &dev_attr_mode.attr,
        &dev_attr_modes.attr,
        &dev_attr_pan.attr,
        &dev_attr_virtual_size.attr,
        &dev_attr_name.attr,
        &dev_attr_stride.attr,
        &dev_attr_rotate.attr,
        &dev_attr_state.attr,
#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
        &dev_attr_bl_curve.attr,
#endif
        NULL,
};

ATTRIBUTE_GROUPS(fb_device);

int fb_device_create(struct fb_info *fb_info)
{
        int node = fb_info->node;
        dev_t devt = MKDEV(FB_MAJOR, node);
        int ret;

        fb_info->dev = device_create_with_groups(fb_class, fb_info->device, devt, fb_info,
                                                 fb_device_groups, "fb%d", node);
        if (IS_ERR(fb_info->dev)) {
                /* Not fatal */
                ret = PTR_ERR(fb_info->dev);
                pr_warn("Unable to create device for framebuffer %d; error %d\n", node, ret);
                fb_info->dev = NULL;
        }

        return 0;
}

void fb_device_destroy(struct fb_info *fb_info)
{
        dev_t devt = MKDEV(FB_MAJOR, fb_info->node);

        if (!fb_info->dev)
                return;

        device_destroy(fb_class, devt);
        fb_info->dev = NULL;
}