// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/drivers/video/omap2/omapfb-ioctl.c
 *
 * Copyright (C) 2008 Nokia Corporation
 * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
 *
 * Some code and ideas taken from drivers/video/omap/ driver
 * by Imre Deak.
 */

#include <linux/fb.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/mm.h>
#include <linux/omapfb.h>
#include <linux/vmalloc.h>
#include <linux/sizes.h>

#include <video/omapfb_dss.h>
#include <video/omapvrfb.h>

#include "omapfb.h"

static u8 get_mem_idx(struct omapfb_info *ofbi)
{
        if (ofbi->id == ofbi->region->id)
                return 0;

        return OMAPFB_MEM_IDX_ENABLED | ofbi->region->id;
}

static struct omapfb2_mem_region *get_mem_region(struct omapfb_info *ofbi,
                                                 u8 mem_idx)
{
        struct omapfb2_device *fbdev = ofbi->fbdev;

        if (mem_idx & OMAPFB_MEM_IDX_ENABLED)
                mem_idx &= OMAPFB_MEM_IDX_MASK;
        else
                mem_idx = ofbi->id;

        if (mem_idx >= fbdev->num_fbs)
                return NULL;

        return &fbdev->regions[mem_idx];
}

static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        struct omap_overlay *ovl;
        struct omap_overlay_info old_info;
        struct omapfb2_mem_region *old_rg, *new_rg;
        int r = 0;

        DBG("omapfb_setup_plane\n");

        if (ofbi->num_overlays == 0) {
                r = -EINVAL;
                goto out;
        }

        /* XXX uses only the first overlay */
        ovl = ofbi->overlays[0];

        old_rg = ofbi->region;
        new_rg = get_mem_region(ofbi, pi->mem_idx);
        if (!new_rg) {
                r = -EINVAL;
                goto out;
        }

        /* Take the locks in a specific order to keep lockdep happy */
        if (old_rg->id < new_rg->id) {
                omapfb_get_mem_region(old_rg);
                omapfb_get_mem_region(new_rg);
        } else if (new_rg->id < old_rg->id) {
                omapfb_get_mem_region(new_rg);
                omapfb_get_mem_region(old_rg);
        } else
                omapfb_get_mem_region(old_rg);

        if (pi->enabled && !new_rg->size) {
                /*
                 * This plane's memory was freed, can't enable it
                 * until it's reallocated.
                 */
                r = -EINVAL;
                goto put_mem;
        }

        ovl->get_overlay_info(ovl, &old_info);

        if (old_rg != new_rg) {
                ofbi->region = new_rg;
                set_fb_fix(fbi);
        }

        if (!pi->enabled) {
                r = ovl->disable(ovl);
                if (r)
                        goto undo;
        }

        if (pi->enabled) {
                r = omapfb_setup_overlay(fbi, ovl, pi->pos_x, pi->pos_y,
                        pi->out_width, pi->out_height);
                if (r)
                        goto undo;
        } else {
                struct omap_overlay_info info;

                ovl->get_overlay_info(ovl, &info);

                info.pos_x = pi->pos_x;
                info.pos_y = pi->pos_y;
                info.out_width = pi->out_width;
                info.out_height = pi->out_height;

                r = ovl->set_overlay_info(ovl, &info);
                if (r)
                        goto undo;
        }

        if (ovl->manager) {
                r = ovl->manager->apply(ovl->manager);
                if (r)
                        goto undo;
        }

        if (pi->enabled) {
                r = ovl->enable(ovl);
                if (r)
                        goto undo;
        }

        /* Release the locks in a specific order to keep lockdep happy */
        if (old_rg->id > new_rg->id) {
                omapfb_put_mem_region(old_rg);
                omapfb_put_mem_region(new_rg);
        } else if (new_rg->id > old_rg->id) {
                omapfb_put_mem_region(new_rg);
                omapfb_put_mem_region(old_rg);
        } else
                omapfb_put_mem_region(old_rg);

        return 0;

 undo:
        if (old_rg != new_rg) {
                ofbi->region = old_rg;
                set_fb_fix(fbi);
        }

        ovl->set_overlay_info(ovl, &old_info);
 put_mem:
        /* Release the locks in a specific order to keep lockdep happy */
        if (old_rg->id > new_rg->id) {
                omapfb_put_mem_region(old_rg);
                omapfb_put_mem_region(new_rg);
        } else if (new_rg->id > old_rg->id) {
                omapfb_put_mem_region(new_rg);
                omapfb_put_mem_region(old_rg);
        } else
                omapfb_put_mem_region(old_rg);
 out:
        dev_err(fbdev->dev, "setup_plane failed\n");

        return r;
}

static int omapfb_query_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);

        if (ofbi->num_overlays == 0) {
                memset(pi, 0, sizeof(*pi));
        } else {
                struct omap_overlay *ovl;
                struct omap_overlay_info ovli;

                ovl = ofbi->overlays[0];
                ovl->get_overlay_info(ovl, &ovli);

                pi->pos_x = ovli.pos_x;
                pi->pos_y = ovli.pos_y;
                pi->enabled = ovl->is_enabled(ovl);
                pi->channel_out = 0; /* xxx */
                pi->mirror = 0;
                pi->mem_idx = get_mem_idx(ofbi);
                pi->out_width = ovli.out_width;
                pi->out_height = ovli.out_height;
        }

        return 0;
}

static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        struct omap_dss_device *display = fb2display(fbi);
        struct omapfb2_mem_region *rg;
        int r = 0, i;
        size_t size;

        if (mi->type != OMAPFB_MEMTYPE_SDRAM)
                return -EINVAL;

        size = PAGE_ALIGN(mi->size);

        if (display && display->driver->sync)
                display->driver->sync(display);

        rg = ofbi->region;

        down_write_nested(&rg->lock, rg->id);
        atomic_inc(&rg->lock_count);

        if (rg->size == size && rg->type == mi->type)
                goto out;

        if (atomic_read(&rg->map_count)) {
                r = -EBUSY;
                goto out;
        }

        for (i = 0; i < fbdev->num_fbs; i++) {
                struct omapfb_info *ofbi2 = FB2OFB(fbdev->fbs[i]);
                int j;

                if (ofbi2->region != rg)
                        continue;

                for (j = 0; j < ofbi2->num_overlays; j++) {
                        struct omap_overlay *ovl;
                        ovl = ofbi2->overlays[j];
                        if (ovl->is_enabled(ovl)) {
                                r = -EBUSY;
                                goto out;
                        }
                }
        }

        r = omapfb_realloc_fbmem(fbi, size, mi->type);
        if (r) {
                dev_err(fbdev->dev, "realloc fbmem failed\n");
                goto out;
        }

 out:
        atomic_dec(&rg->lock_count);
        up_write(&rg->lock);

        return r;
}

static int omapfb_query_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_mem_region *rg;

        rg = omapfb_get_mem_region(ofbi->region);
        memset(mi, 0, sizeof(*mi));

        mi->size = rg->size;
        mi->type = rg->type;

        omapfb_put_mem_region(rg);

        return 0;
}

static int omapfb_update_window(struct fb_info *fbi,
                u32 x, u32 y, u32 w, u32 h)
{
        struct omap_dss_device *display = fb2display(fbi);
        u16 dw, dh;

        if (!display)
                return 0;

        if (w == 0 || h == 0)
                return 0;

        display->driver->get_resolution(display, &dw, &dh);

        if (x + w > dw || y + h > dh)
                return -EINVAL;

        return display->driver->update(display, x, y, w, h);
}

int omapfb_set_update_mode(struct fb_info *fbi,
                                   enum omapfb_update_mode mode)
{
        struct omap_dss_device *display = fb2display(fbi);
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        struct omapfb_display_data *d;
        int r;

        if (!display)
                return -EINVAL;

        if (mode != OMAPFB_AUTO_UPDATE && mode != OMAPFB_MANUAL_UPDATE)
                return -EINVAL;

        omapfb_lock(fbdev);

        d = get_display_data(fbdev, display);

        if (d->update_mode == mode) {
                omapfb_unlock(fbdev);
                return 0;
        }

        r = 0;

        if (display->caps & OMAP_DSS_DISPLAY_CAP_MANUAL_UPDATE) {
                if (mode == OMAPFB_AUTO_UPDATE)
                        omapfb_start_auto_update(fbdev, display);
                else /* MANUAL_UPDATE */
                        omapfb_stop_auto_update(fbdev, display);

                d->update_mode = mode;
        } else { /* AUTO_UPDATE */
                if (mode == OMAPFB_MANUAL_UPDATE)
                        r = -EINVAL;
        }

        omapfb_unlock(fbdev);

        return r;
}

int omapfb_get_update_mode(struct fb_info *fbi,
                enum omapfb_update_mode *mode)
{
        struct omap_dss_device *display = fb2display(fbi);
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        struct omapfb_display_data *d;

        if (!display)
                return -EINVAL;

        omapfb_lock(fbdev);

        d = get_display_data(fbdev, display);

        *mode = d->update_mode;

        omapfb_unlock(fbdev);

        return 0;
}

/* XXX this color key handling is a hack... */
static struct omapfb_color_key omapfb_color_keys[2];

static int _omapfb_set_color_key(struct omap_overlay_manager *mgr,
                struct omapfb_color_key *ck)
{
        struct omap_overlay_manager_info info;
        enum omap_dss_trans_key_type kt;
        int r;

        mgr->get_manager_info(mgr, &info);

        if (ck->key_type == OMAPFB_COLOR_KEY_DISABLED) {
                info.trans_enabled = false;
                omapfb_color_keys[mgr->id] = *ck;

                r = mgr->set_manager_info(mgr, &info);
                if (r)
                        return r;

                r = mgr->apply(mgr);

                return r;
        }

        switch (ck->key_type) {
        case OMAPFB_COLOR_KEY_GFX_DST:
                kt = OMAP_DSS_COLOR_KEY_GFX_DST;
                break;
        case OMAPFB_COLOR_KEY_VID_SRC:
                kt = OMAP_DSS_COLOR_KEY_VID_SRC;
                break;
        default:
                return -EINVAL;
        }

        info.default_color = ck->background;
        info.trans_key = ck->trans_key;
        info.trans_key_type = kt;
        info.trans_enabled = true;

        omapfb_color_keys[mgr->id] = *ck;

        r = mgr->set_manager_info(mgr, &info);
        if (r)
                return r;

        r = mgr->apply(mgr);

        return r;
}

static int omapfb_set_color_key(struct fb_info *fbi,
                struct omapfb_color_key *ck)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        int r;
        int i;
        struct omap_overlay_manager *mgr = NULL;

        omapfb_lock(fbdev);

        for (i = 0; i < ofbi->num_overlays; i++) {
                if (ofbi->overlays[i]->manager) {
                        mgr = ofbi->overlays[i]->manager;
                        break;
                }
        }

        if (!mgr) {
                r = -EINVAL;
                goto err;
        }

        r = _omapfb_set_color_key(mgr, ck);
err:
        omapfb_unlock(fbdev);

        return r;
}

static int omapfb_get_color_key(struct fb_info *fbi,
                struct omapfb_color_key *ck)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        struct omap_overlay_manager *mgr = NULL;
        int r = 0;
        int i;

        omapfb_lock(fbdev);

        for (i = 0; i < ofbi->num_overlays; i++) {
                if (ofbi->overlays[i]->manager) {
                        mgr = ofbi->overlays[i]->manager;
                        break;
                }
        }

        if (!mgr) {
                r = -EINVAL;
                goto err;
        }

        *ck = omapfb_color_keys[mgr->id];
err:
        omapfb_unlock(fbdev);

        return r;
}

static int omapfb_memory_read(struct fb_info *fbi,
                struct omapfb_memory_read *mr)
{
        struct omap_dss_device *display = fb2display(fbi);
        void *buf;
        int r;

        if (!display || !display->driver->memory_read)
                return -ENOENT;

        if (mr->w > 4096 || mr->h > 4096)
                return -EINVAL;

        if (mr->w * mr->h * 3 > mr->buffer_size)
                return -EINVAL;

        buf = vmalloc(mr->buffer_size);
        if (!buf) {
                DBG("vmalloc failed\n");
                return -ENOMEM;
        }

        r = display->driver->memory_read(display, buf, mr->buffer_size,
                        mr->x, mr->y, mr->w, mr->h);

        if (r > 0) {
                if (copy_to_user(mr->buffer, buf, r))
                        r = -EFAULT;
        }

        vfree(buf);

        return r;
}

static int omapfb_get_ovl_colormode(struct omapfb2_device *fbdev,
                             struct omapfb_ovl_colormode *mode)
{
        int ovl_idx = mode->overlay_idx;
        int mode_idx = mode->mode_idx;
        struct omap_overlay *ovl;
        enum omap_color_mode supported_modes;
        struct fb_var_screeninfo var;
        int i;

        if (ovl_idx >= fbdev->num_overlays)
                return -ENODEV;
        ovl = fbdev->overlays[ovl_idx];
        supported_modes = ovl->supported_modes;

        mode_idx = mode->mode_idx;

        for (i = 0; i < sizeof(supported_modes) * 8; i++) {
                if (!(supported_modes & (1 << i)))
                        continue;
                /*
                 * It's possible that the FB doesn't support a mode
                 * that is supported by the overlay, so call the
                 * following here.
                 */
                if (dss_mode_to_fb_mode(1 << i, &var) < 0)
                        continue;

                mode_idx--;
                if (mode_idx < 0)
                        break;
        }

        if (i == sizeof(supported_modes) * 8)
                return -ENOENT;

        mode->bits_per_pixel = var.bits_per_pixel;
        mode->nonstd = var.nonstd;
        mode->red = var.red;
        mode->green = var.green;
        mode->blue = var.blue;
        mode->transp = var.transp;

        return 0;
}

static int omapfb_wait_for_go(struct fb_info *fbi)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        int r = 0;
        int i;

        for (i = 0; i < ofbi->num_overlays; ++i) {
                struct omap_overlay *ovl = ofbi->overlays[i];
                r = ovl->wait_for_go(ovl);
                if (r)
                        break;
        }

        return r;
}

int omapfb_ioctl(struct fb_info *fbi, unsigned int cmd, unsigned long arg)
{
        struct omapfb_info *ofbi = FB2OFB(fbi);
        struct omapfb2_device *fbdev = ofbi->fbdev;
        struct omap_dss_device *display = fb2display(fbi);
        struct omap_overlay_manager *mgr;

        union {
                struct omapfb_update_window_old uwnd_o;
                struct omapfb_update_window     uwnd;
                struct omapfb_plane_info        plane_info;
                struct omapfb_caps              caps;
                struct omapfb_mem_info          mem_info;
                struct omapfb_color_key         color_key;
                struct omapfb_ovl_colormode     ovl_colormode;
                enum omapfb_update_mode         update_mode;
                int test_num;
                struct omapfb_memory_read       memory_read;
                struct omapfb_vram_info         vram_info;
                struct omapfb_tearsync_info     tearsync_info;
                struct omapfb_display_info      display_info;
                u32                             crt;
        } p;

        int r = 0;

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

        switch (cmd) {
        case OMAPFB_SYNC_GFX:
                DBG("ioctl SYNC_GFX\n");
                if (!display || !display->driver->sync) {
                        /* DSS1 never returns an error here, so we neither */
                        /*r = -EINVAL;*/
                        break;
                }

                r = display->driver->sync(display);
                break;

        case OMAPFB_UPDATE_WINDOW_OLD:
                DBG("ioctl UPDATE_WINDOW_OLD\n");
                if (!display || !display->driver->update) {
                        r = -EINVAL;
                        break;
                }

                if (copy_from_user(&p.uwnd_o,
                                        (void __user *)arg,
                                        sizeof(p.uwnd_o))) {
                        r = -EFAULT;
                        break;
                }

                r = omapfb_update_window(fbi, p.uwnd_o.x, p.uwnd_o.y,
                                p.uwnd_o.width, p.uwnd_o.height);
                break;

        case OMAPFB_UPDATE_WINDOW:
                DBG("ioctl UPDATE_WINDOW\n");
                if (!display || !display->driver->update) {
                        r = -EINVAL;
                        break;
                }

                if (copy_from_user(&p.uwnd, (void __user *)arg,
                                        sizeof(p.uwnd))) {
                        r = -EFAULT;
                        break;
                }

                r = omapfb_update_window(fbi, p.uwnd.x, p.uwnd.y,
                                p.uwnd.width, p.uwnd.height);
                break;

        case OMAPFB_SETUP_PLANE:
                DBG("ioctl SETUP_PLANE\n");
                if (copy_from_user(&p.plane_info, (void __user *)arg,
                                        sizeof(p.plane_info)))
                        r = -EFAULT;
                else
                        r = omapfb_setup_plane(fbi, &p.plane_info);
                break;

        case OMAPFB_QUERY_PLANE:
                DBG("ioctl QUERY_PLANE\n");
                r = omapfb_query_plane(fbi, &p.plane_info);
                if (r < 0)
                        break;
                if (copy_to_user((void __user *)arg, &p.plane_info,
                                        sizeof(p.plane_info)))
                        r = -EFAULT;
                break;

        case OMAPFB_SETUP_MEM:
                DBG("ioctl SETUP_MEM\n");
                if (copy_from_user(&p.mem_info, (void __user *)arg,
                                        sizeof(p.mem_info)))
                        r = -EFAULT;
                else
                        r = omapfb_setup_mem(fbi, &p.mem_info);
                break;

        case OMAPFB_QUERY_MEM:
                DBG("ioctl QUERY_MEM\n");
                r = omapfb_query_mem(fbi, &p.mem_info);
                if (r < 0)
                        break;
                if (copy_to_user((void __user *)arg, &p.mem_info,
                                        sizeof(p.mem_info)))
                        r = -EFAULT;
                break;

        case OMAPFB_GET_CAPS:
                DBG("ioctl GET_CAPS\n");
                if (!display) {
                        r = -EINVAL;
                        break;
                }

                memset(&p.caps, 0, sizeof(p.caps));
                if (display->caps & OMAP_DSS_DISPLAY_CAP_MANUAL_UPDATE)
                        p.caps.ctrl |= OMAPFB_CAPS_MANUAL_UPDATE;
                if (display->caps & OMAP_DSS_DISPLAY_CAP_TEAR_ELIM)
                        p.caps.ctrl |= OMAPFB_CAPS_TEARSYNC;

                if (copy_to_user((void __user *)arg, &p.caps, sizeof(p.caps)))
                        r = -EFAULT;
                break;

        case OMAPFB_GET_OVERLAY_COLORMODE:
                DBG("ioctl GET_OVERLAY_COLORMODE\n");
                if (copy_from_user(&p.ovl_colormode, (void __user *)arg,
                                   sizeof(p.ovl_colormode))) {
                        r = -EFAULT;
                        break;
                }
                r = omapfb_get_ovl_colormode(fbdev, &p.ovl_colormode);
                if (r < 0)
                        break;
                if (copy_to_user((void __user *)arg, &p.ovl_colormode,
                                 sizeof(p.ovl_colormode)))
                        r = -EFAULT;
                break;

        case OMAPFB_SET_UPDATE_MODE:
                DBG("ioctl SET_UPDATE_MODE\n");
                if (get_user(p.update_mode, (int __user *)arg))
                        r = -EFAULT;
                else
                        r = omapfb_set_update_mode(fbi, p.update_mode);
                break;

        case OMAPFB_GET_UPDATE_MODE:
                DBG("ioctl GET_UPDATE_MODE\n");
                r = omapfb_get_update_mode(fbi, &p.update_mode);
                if (r)
                        break;
                if (put_user(p.update_mode,
                                        (enum omapfb_update_mode __user *)arg))
                        r = -EFAULT;
                break;

        case OMAPFB_SET_COLOR_KEY:
                DBG("ioctl SET_COLOR_KEY\n");
                if (copy_from_user(&p.color_key, (void __user *)arg,
                                   sizeof(p.color_key)))
                        r = -EFAULT;
                else
                        r = omapfb_set_color_key(fbi, &p.color_key);
                break;

        case OMAPFB_GET_COLOR_KEY:
                DBG("ioctl GET_COLOR_KEY\n");
                r = omapfb_get_color_key(fbi, &p.color_key);
                if (r)
                        break;
                if (copy_to_user((void __user *)arg, &p.color_key,
                                 sizeof(p.color_key)))
                        r = -EFAULT;
                break;

        case FBIO_WAITFORVSYNC:
                if (get_user(p.crt, (__u32 __user *)arg)) {
                        r = -EFAULT;
                        break;
                }
                if (p.crt != 0) {
                        r = -ENODEV;
                        break;
                }
                fallthrough;

        case OMAPFB_WAITFORVSYNC:
                DBG("ioctl WAITFORVSYNC\n");

                if (!display) {
                        r = -EINVAL;
                        break;
                }

                mgr = omapdss_find_mgr_from_display(display);
                if (!mgr) {
                        r = -EINVAL;
                        break;
                }

                r = mgr->wait_for_vsync(mgr);
                break;

        case OMAPFB_WAITFORGO:
                DBG("ioctl WAITFORGO\n");
                if (!display) {
                        r = -EINVAL;
                        break;
                }

                r = omapfb_wait_for_go(fbi);
                break;

        /* LCD and CTRL tests do the same thing for backward
         * compatibility */
        case OMAPFB_LCD_TEST:
                DBG("ioctl LCD_TEST\n");
                if (get_user(p.test_num, (int __user *)arg)) {
                        r = -EFAULT;
                        break;
                }
                if (!display || !display->driver->run_test) {
                        r = -EINVAL;
                        break;
                }

                r = display->driver->run_test(display, p.test_num);

                break;

        case OMAPFB_CTRL_TEST:
                DBG("ioctl CTRL_TEST\n");
                if (get_user(p.test_num, (int __user *)arg)) {
                        r = -EFAULT;
                        break;
                }
                if (!display || !display->driver->run_test) {
                        r = -EINVAL;
                        break;
                }

                r = display->driver->run_test(display, p.test_num);

                break;

        case OMAPFB_MEMORY_READ:
                DBG("ioctl MEMORY_READ\n");

                if (copy_from_user(&p.memory_read, (void __user *)arg,
                                        sizeof(p.memory_read))) {
                        r = -EFAULT;
                        break;
                }

                r = omapfb_memory_read(fbi, &p.memory_read);

                break;

        case OMAPFB_GET_VRAM_INFO: {
                DBG("ioctl GET_VRAM_INFO\n");

                /*
                 * We don't have the ability to get this vram info anymore.
                 * Fill in something that should keep the applications working.
                 */
                p.vram_info.total = SZ_1M * 64;
                p.vram_info.free = SZ_1M * 64;
                p.vram_info.largest_free_block = SZ_1M * 64;

                if (copy_to_user((void __user *)arg, &p.vram_info,
                                        sizeof(p.vram_info)))
                        r = -EFAULT;
                break;
        }

        case OMAPFB_SET_TEARSYNC: {
                DBG("ioctl SET_TEARSYNC\n");

                if (copy_from_user(&p.tearsync_info, (void __user *)arg,
                                        sizeof(p.tearsync_info))) {
                        r = -EFAULT;
                        break;
                }

                if (!display || !display->driver->enable_te) {
                        r = -ENODEV;
                        break;
                }

                r = display->driver->enable_te(display,
                                !!p.tearsync_info.enabled);

                break;
        }

        case OMAPFB_GET_DISPLAY_INFO: {
                u16 xres, yres;

                DBG("ioctl GET_DISPLAY_INFO\n");

                if (display == NULL) {
                        r = -ENODEV;
                        break;
                }

                display->driver->get_resolution(display, &xres, &yres);

                p.display_info.xres = xres;
                p.display_info.yres = yres;

                if (display->driver->get_dimensions) {
                        u32 w, h;
                        display->driver->get_dimensions(display, &w, &h);
                        p.display_info.width = w;
                        p.display_info.height = h;
                } else {
                        p.display_info.width = 0;
                        p.display_info.height = 0;
                }

                if (copy_to_user((void __user *)arg, &p.display_info,
                                        sizeof(p.display_info)))
                        r = -EFAULT;
                break;
        }

        default:
                dev_err(fbdev->dev, "Unknown ioctl 0x%x\n", cmd);
                r = -EINVAL;
        }

        if (r < 0)
                DBG("ioctl failed: %d\n", r);

        return r;
}