// SPDX-License-Identifier: GPL-2.0-only
/**************************************************************************
 * Copyright (c) 2007-2011, Intel Corporation.
 * All Rights Reserved.
 *
 **************************************************************************/

#include <linux/fb.h>

#include <drm/drm_crtc_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_framebuffer.h>

#include "gem.h"
#include "psb_drv.h"

/*
 * VM area struct
 */

static vm_fault_t psb_fbdev_vm_fault(struct vm_fault *vmf)
{
        struct vm_area_struct *vma = vmf->vma;
        struct fb_info *info = vma->vm_private_data;
        unsigned long address = vmf->address - (vmf->pgoff << PAGE_SHIFT);
        unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT;
        vm_fault_t err = VM_FAULT_SIGBUS;
        unsigned long page_num = vma_pages(vma);
        unsigned long i;

        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

        for (i = 0; i < page_num; ++i) {
                err = vmf_insert_mixed(vma, address, pfn);
                if (unlikely(err & VM_FAULT_ERROR))
                        break;
                address += PAGE_SIZE;
                ++pfn;
        }

        return err;
}

static const struct vm_operations_struct psb_fbdev_vm_ops = {
        .fault  = psb_fbdev_vm_fault,
};

/*
 * struct fb_ops
 */

static int psb_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
        if (vma->vm_pgoff != 0)
                return -EINVAL;
        if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
                return -EINVAL;

        /*
         * If this is a GEM object then info->screen_base is the virtual
         * kernel remapping of the object. FIXME: Review if this is
         * suitable for our mmap work
         */
        vma->vm_ops = &psb_fbdev_vm_ops;
        vma->vm_private_data = info;
        vm_flags_set(vma, VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP);

        return 0;
}

static void psb_fbdev_fb_destroy(struct fb_info *info)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct drm_framebuffer *fb = fb_helper->fb;
        struct drm_gem_object *obj = fb->obj[0];

        drm_fb_helper_fini(fb_helper);

        drm_framebuffer_unregister_private(fb);
        drm_framebuffer_cleanup(fb);
        kfree(fb);

        drm_gem_object_put(obj);

        drm_client_release(&fb_helper->client);
}

static const struct fb_ops psb_fbdev_fb_ops = {
        .owner = THIS_MODULE,
        __FB_DEFAULT_IOMEM_OPS_RDWR,
        DRM_FB_HELPER_DEFAULT_OPS,
        __FB_DEFAULT_IOMEM_OPS_DRAW,
        .fb_mmap = psb_fbdev_fb_mmap,
        .fb_destroy = psb_fbdev_fb_destroy,
};

static const struct drm_fb_helper_funcs psb_fbdev_fb_helper_funcs = {
};

/*
 * struct drm_driver
 */

int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
                                 struct drm_fb_helper_surface_size *sizes)
{
        struct drm_device *dev = fb_helper->dev;
        struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
        struct pci_dev *pdev = to_pci_dev(dev->dev);
        struct fb_info *info = fb_helper->info;
        struct drm_framebuffer *fb;
        struct drm_mode_fb_cmd2 mode_cmd = { };
        int size;
        int ret;
        struct psb_gem_object *backing;
        struct drm_gem_object *obj;
        u32 bpp, depth;

        /* No 24-bit packed mode */
        if (sizes->surface_bpp == 24) {
                sizes->surface_bpp = 32;
                sizes->surface_depth = 24;
        }
        bpp = sizes->surface_bpp;
        depth = sizes->surface_depth;

        /*
         * If the mode does not fit in 32 bit then switch to 16 bit to get
         * a console on full resolution. The X mode setting server will
         * allocate its own 32-bit GEM framebuffer.
         */
        size = ALIGN(sizes->surface_width * DIV_ROUND_UP(bpp, 8), 64) *
                     sizes->surface_height;
        size = ALIGN(size, PAGE_SIZE);

        if (size > dev_priv->vram_stolen_size) {
                sizes->surface_bpp = 16;
                sizes->surface_depth = 16;
        }
        bpp = sizes->surface_bpp;
        depth = sizes->surface_depth;

        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;
        mode_cmd.pitches[0] = ALIGN(mode_cmd.width * DIV_ROUND_UP(bpp, 8), 64);
        mode_cmd.pixel_format = drm_mode_legacy_fb_format(bpp, depth);

        size = mode_cmd.pitches[0] * mode_cmd.height;
        size = ALIGN(size, PAGE_SIZE);

        /* Allocate the framebuffer in the GTT with stolen page backing */
        backing = psb_gem_create(dev, size, "fb", true, PAGE_SIZE);
        if (IS_ERR(backing))
                return PTR_ERR(backing);
        obj = &backing->base;

        fb = psb_framebuffer_create(dev,
                                    drm_get_format_info(dev, mode_cmd.pixel_format,
                                                        mode_cmd.modifier[0]),
                                    &mode_cmd, obj);
        if (IS_ERR(fb)) {
                ret = PTR_ERR(fb);
                goto err_drm_gem_object_put;
        }

        fb_helper->funcs = &psb_fbdev_fb_helper_funcs;
        fb_helper->fb = fb;

        info->fbops = &psb_fbdev_fb_ops;

        /* Accessed stolen memory directly */
        info->screen_base = dev_priv->vram_addr + backing->offset;
        info->screen_size = size;

        drm_fb_helper_fill_info(info, fb_helper, sizes);

        info->fix.smem_start = dev_priv->stolen_base + backing->offset;
        info->fix.smem_len = size;
        info->fix.ywrapstep = 0;
        info->fix.ypanstep = 0;
        info->fix.mmio_start = pci_resource_start(pdev, 0);
        info->fix.mmio_len = pci_resource_len(pdev, 0);

        fb_memset_io(info->screen_base, 0, info->screen_size);

        /* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */

        dev_dbg(dev->dev, "allocated %dx%d fb\n", fb->width, fb->height);

        return 0;

err_drm_gem_object_put:
        drm_gem_object_put(obj);
        return ret;
}