/*
 * Copyright (C) 2016 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 "mdp5_kms.h"

int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane,
                     uint32_t caps, uint32_t blkcfg,
                     struct mdp5_hw_pipe **hwpipe,
                     struct mdp5_hw_pipe **r_hwpipe)
{
        struct msm_drm_private *priv = s->dev->dev_private;
        struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
        struct mdp5_global_state *new_global_state, *old_global_state;
        struct mdp5_hw_pipe_state *old_state, *new_state;
        int i, j;

        new_global_state = mdp5_get_global_state(s);
        if (IS_ERR(new_global_state))
                return PTR_ERR(new_global_state);

        /* grab old_state after mdp5_get_global_state(), since now we hold lock: */
        old_global_state = mdp5_get_existing_global_state(mdp5_kms);

        old_state = &old_global_state->hwpipe;
        new_state = &new_global_state->hwpipe;

        for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
                struct mdp5_hw_pipe *cur = mdp5_kms->hwpipes[i];

                /* skip if already in-use.. check both new and old state,
                 * since we cannot immediately re-use a pipe that is
                 * released in the current update in some cases:
                 *  (1) mdp5 can have SMP (non-double-buffered)
                 *  (2) hw pipe previously assigned to different CRTC
                 *      (vblanks might not be aligned)
                 */
                if (new_state->hwpipe_to_plane[cur->idx] ||
                                old_state->hwpipe_to_plane[cur->idx])
                        continue;

                /* skip if doesn't support some required caps: */
                if (caps & ~cur->caps)
                        continue;

                /*
                 * don't assign a cursor pipe to a plane that isn't going to
                 * be used as a cursor
                 */
                if (cur->caps & MDP_PIPE_CAP_CURSOR &&
                                plane->type != DRM_PLANE_TYPE_CURSOR)
                        continue;

                /* possible candidate, take the one with the
                 * fewest unneeded caps bits set:
                 */
                if (!(*hwpipe) || (hweight_long(cur->caps & ~caps) <
                                   hweight_long((*hwpipe)->caps & ~caps))) {
                        bool r_found = false;

                        if (r_hwpipe) {
                                for (j = i + 1; j < mdp5_kms->num_hwpipes;
                                     j++) {
                                        struct mdp5_hw_pipe *r_cur =
                                                        mdp5_kms->hwpipes[j];

                                        /* reject different types of hwpipes */
                                        if (r_cur->caps != cur->caps)
                                                continue;

                                        /* respect priority, eg. VIG0 > VIG1 */
                                        if (cur->pipe > r_cur->pipe)
                                                continue;

                                        *r_hwpipe = r_cur;
                                        r_found = true;
                                        break;
                                }
                        }

                        if (!r_hwpipe || r_found)
                                *hwpipe = cur;
                }
        }

        if (!(*hwpipe))
                return -ENOMEM;

        if (r_hwpipe && !(*r_hwpipe))
                return -ENOMEM;

        if (mdp5_kms->smp) {
                int ret;

                /* We don't support SMP and 2 hwpipes/plane together */
                WARN_ON(r_hwpipe);

                DBG("%s: alloc SMP blocks", (*hwpipe)->name);
                ret = mdp5_smp_assign(mdp5_kms->smp, &new_global_state->smp,
                                (*hwpipe)->pipe, blkcfg);
                if (ret)
                        return -ENOMEM;

                (*hwpipe)->blkcfg = blkcfg;
        }

        DBG("%s: assign to plane %s for caps %x",
                        (*hwpipe)->name, plane->name, caps);
        new_state->hwpipe_to_plane[(*hwpipe)->idx] = plane;

        if (r_hwpipe) {
                DBG("%s: assign to right of plane %s for caps %x",
                    (*r_hwpipe)->name, plane->name, caps);
                new_state->hwpipe_to_plane[(*r_hwpipe)->idx] = plane;
        }

        return 0;
}

void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe)
{
        struct msm_drm_private *priv = s->dev->dev_private;
        struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
        struct mdp5_global_state *state = mdp5_get_global_state(s);
        struct mdp5_hw_pipe_state *new_state = &state->hwpipe;

        if (!hwpipe)
                return;

        if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx]))
                return;

        DBG("%s: release from plane %s", hwpipe->name,
                new_state->hwpipe_to_plane[hwpipe->idx]->name);

        if (mdp5_kms->smp) {
                DBG("%s: free SMP blocks", hwpipe->name);
                mdp5_smp_release(mdp5_kms->smp, &state->smp, hwpipe->pipe);
        }

        new_state->hwpipe_to_plane[hwpipe->idx] = NULL;
}

void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe)
{
        kfree(hwpipe);
}

struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe,
                uint32_t reg_offset, uint32_t caps)
{
        struct mdp5_hw_pipe *hwpipe;

        hwpipe = kzalloc(sizeof(*hwpipe), GFP_KERNEL);
        if (!hwpipe)
                return ERR_PTR(-ENOMEM);

        hwpipe->name = pipe2name(pipe);
        hwpipe->pipe = pipe;
        hwpipe->reg_offset = reg_offset;
        hwpipe->caps = caps;
        hwpipe->flush_mask = mdp_ctl_flush_mask_pipe(pipe);

        return hwpipe;
}