/*
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>

#include "msm_drv.h"
#include "msm_kms.h"
#include "msm_gem.h"

struct msm_framebuffer {
        struct drm_framebuffer base;
        const struct msm_format *format;
};
#define to_msm_framebuffer(x) container_of(x, struct msm_framebuffer, base)

static struct drm_framebuffer *msm_framebuffer_init(struct drm_device *dev,
                const struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos);

static const struct drm_framebuffer_funcs msm_framebuffer_funcs = {
        .create_handle = drm_gem_fb_create_handle,
        .destroy = drm_gem_fb_destroy,
};

#ifdef CONFIG_DEBUG_FS
void msm_framebuffer_describe(struct drm_framebuffer *fb, struct seq_file *m)
{
        int i, n = fb->format->num_planes;

        seq_printf(m, "fb: %dx%d@%4.4s (%2d, ID:%d)\n",
                        fb->width, fb->height, (char *)&fb->format->format,
                        drm_framebuffer_read_refcount(fb), fb->base.id);

        for (i = 0; i < n; i++) {
                seq_printf(m, "   %d: offset=%d pitch=%d, obj: ",
                                i, fb->offsets[i], fb->pitches[i]);
                msm_gem_describe(fb->obj[i], m);
        }
}
#endif

/* prepare/pin all the fb's bo's for scanout.  Note that it is not valid
 * to prepare an fb more multiple different initiator 'id's.  But that
 * should be fine, since only the scanout (mdpN) side of things needs
 * this, the gpu doesn't care about fb's.
 */
int msm_framebuffer_prepare(struct drm_framebuffer *fb,
                struct msm_gem_address_space *aspace)
{
        int ret, i, n = fb->format->num_planes;
        uint64_t iova;

        for (i = 0; i < n; i++) {
                ret = msm_gem_get_iova(fb->obj[i], aspace, &iova);
                DBG("FB[%u]: iova[%d]: %08llx (%d)", fb->base.id, i, iova, ret);
                if (ret)
                        return ret;
        }

        return 0;
}

void msm_framebuffer_cleanup(struct drm_framebuffer *fb,
                struct msm_gem_address_space *aspace)
{
        int i, n = fb->format->num_planes;

        for (i = 0; i < n; i++)
                msm_gem_put_iova(fb->obj[i], aspace);
}

uint32_t msm_framebuffer_iova(struct drm_framebuffer *fb,
                struct msm_gem_address_space *aspace, int plane)
{
        if (!fb->obj[plane])
                return 0;
        return msm_gem_iova(fb->obj[plane], aspace) + fb->offsets[plane];
}

struct drm_gem_object *msm_framebuffer_bo(struct drm_framebuffer *fb, int plane)
{
        return drm_gem_fb_get_obj(fb, plane);
}

const struct msm_format *msm_framebuffer_format(struct drm_framebuffer *fb)
{
        struct msm_framebuffer *msm_fb = to_msm_framebuffer(fb);
        return msm_fb->format;
}

struct drm_framebuffer *msm_framebuffer_create(struct drm_device *dev,
                struct drm_file *file, const struct drm_mode_fb_cmd2 *mode_cmd)
{
        struct drm_gem_object *bos[4] = {0};
        struct drm_framebuffer *fb;
        int ret, i, n = drm_format_num_planes(mode_cmd->pixel_format);

        for (i = 0; i < n; i++) {
                bos[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]);
                if (!bos[i]) {
                        ret = -ENXIO;
                        goto out_unref;
                }
        }

        fb = msm_framebuffer_init(dev, mode_cmd, bos);
        if (IS_ERR(fb)) {
                ret = PTR_ERR(fb);
                goto out_unref;
        }

        return fb;

out_unref:
        for (i = 0; i < n; i++)
                drm_gem_object_put_unlocked(bos[i]);
        return ERR_PTR(ret);
}

static struct drm_framebuffer *msm_framebuffer_init(struct drm_device *dev,
                const struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos)
{
        struct msm_drm_private *priv = dev->dev_private;
        struct msm_kms *kms = priv->kms;
        struct msm_framebuffer *msm_fb = NULL;
        struct drm_framebuffer *fb;
        const struct msm_format *format;
        int ret, i, n;
        unsigned int hsub, vsub;

        DBG("create framebuffer: dev=%p, mode_cmd=%p (%dx%d@%4.4s)",
                        dev, mode_cmd, mode_cmd->width, mode_cmd->height,
                        (char *)&mode_cmd->pixel_format);

        n = drm_format_num_planes(mode_cmd->pixel_format);
        hsub = drm_format_horz_chroma_subsampling(mode_cmd->pixel_format);
        vsub = drm_format_vert_chroma_subsampling(mode_cmd->pixel_format);

        format = kms->funcs->get_format(kms, mode_cmd->pixel_format,
                        mode_cmd->modifier[0]);
        if (!format) {
                dev_err(dev->dev, "unsupported pixel format: %4.4s\n",
                                (char *)&mode_cmd->pixel_format);
                ret = -EINVAL;
                goto fail;
        }

        msm_fb = kzalloc(sizeof(*msm_fb), GFP_KERNEL);
        if (!msm_fb) {
                ret = -ENOMEM;
                goto fail;
        }

        fb = &msm_fb->base;

        msm_fb->format = format;

        if (n > ARRAY_SIZE(fb->obj)) {
                ret = -EINVAL;
                goto fail;
        }

        for (i = 0; i < n; i++) {
                unsigned int width = mode_cmd->width / (i ? hsub : 1);
                unsigned int height = mode_cmd->height / (i ? vsub : 1);
                unsigned int min_size;

                min_size = (height - 1) * mode_cmd->pitches[i]
                         + width * drm_format_plane_cpp(mode_cmd->pixel_format, i)
                         + mode_cmd->offsets[i];

                if (bos[i]->size < min_size) {
                        ret = -EINVAL;
                        goto fail;
                }

                msm_fb->base.obj[i] = bos[i];
        }

        drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);

        ret = drm_framebuffer_init(dev, fb, &msm_framebuffer_funcs);
        if (ret) {
                dev_err(dev->dev, "framebuffer init failed: %d\n", ret);
                goto fail;
        }

        DBG("create: FB ID: %d (%p)", fb->base.id, fb);

        return fb;

fail:
        kfree(msm_fb);

        return ERR_PTR(ret);
}

struct drm_framebuffer *
msm_alloc_stolen_fb(struct drm_device *dev, int w, int h, int p, uint32_t format)
{
        struct drm_mode_fb_cmd2 mode_cmd = {
                .pixel_format = format,
                .width = w,
                .height = h,
                .pitches = { p },
        };
        struct drm_gem_object *bo;
        struct drm_framebuffer *fb;
        int size;

        /* allocate backing bo */
        size = mode_cmd.pitches[0] * mode_cmd.height;
        DBG("allocating %d bytes for fb %d", size, dev->primary->index);
        bo = msm_gem_new(dev, size, MSM_BO_SCANOUT | MSM_BO_WC | MSM_BO_STOLEN);
        if (IS_ERR(bo)) {
                dev_warn(dev->dev, "could not allocate stolen bo\n");
                /* try regular bo: */
                bo = msm_gem_new(dev, size, MSM_BO_SCANOUT | MSM_BO_WC);
        }
        if (IS_ERR(bo)) {
                dev_err(dev->dev, "failed to allocate buffer object\n");
                return ERR_CAST(bo);
        }

        fb = msm_framebuffer_init(dev, &mode_cmd, &bo);
        if (IS_ERR(fb)) {
                dev_err(dev->dev, "failed to allocate fb\n");
                /* note: if fb creation failed, we can't rely on fb destroy
                 * to unref the bo:
                 */
                drm_gem_object_put_unlocked(bo);
                return ERR_CAST(fb);
        }

        return fb;
}