/*
 * Copyright © 2015 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

/**
 * DOC: atomic modeset support
 *
 * The functions here implement the state management and hardware programming
 * dispatch required by the atomic modeset infrastructure.
 * See intel_atomic_plane.c for the plane-specific atomic functionality.
 */

#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_plane_helper.h>
#include "intel_drv.h"

/**
 * intel_connector_atomic_get_property - fetch connector property value
 * @connector: connector to fetch property for
 * @state: state containing the property value
 * @property: property to look up
 * @val: pointer to write property value into
 *
 * The DRM core does not store shadow copies of properties for
 * atomic-capable drivers.  This entrypoint is used to fetch
 * the current value of a driver-specific connector property.
 */
int
intel_connector_atomic_get_property(struct drm_connector *connector,
                                    const struct drm_connector_state *state,
                                    struct drm_property *property,
                                    uint64_t *val)
{
        int i;

        /*
         * TODO: We only have atomic modeset for planes at the moment, so the
         * crtc/connector code isn't quite ready yet.  Until it's ready,
         * continue to look up all property values in the DRM's shadow copy
         * in obj->properties->values[].
         *
         * When the crtc/connector state work matures, this function should
         * be updated to read the values out of the state structure instead.
         */
        for (i = 0; i < connector->base.properties->count; i++) {
                if (connector->base.properties->properties[i] == property) {
                        *val = connector->base.properties->values[i];
                        return 0;
                }
        }

        return -EINVAL;
}

/*
 * intel_crtc_duplicate_state - duplicate crtc state
 * @crtc: drm crtc
 *
 * Allocates and returns a copy of the crtc state (both common and
 * Intel-specific) for the specified crtc.
 *
 * Returns: The newly allocated crtc state, or NULL on failure.
 */
struct drm_crtc_state *
intel_crtc_duplicate_state(struct drm_crtc *crtc)
{
        struct intel_crtc_state *crtc_state;

        crtc_state = kmemdup(crtc->state, sizeof(*crtc_state), GFP_KERNEL);
        if (!crtc_state)
                return NULL;

        __drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->base);

        crtc_state->update_pipe = false;
        crtc_state->disable_lp_wm = false;
        crtc_state->disable_cxsr = false;
        crtc_state->wm_changed = false;
        crtc_state->fb_changed = false;

        return &crtc_state->base;
}

/**
 * intel_crtc_destroy_state - destroy crtc state
 * @crtc: drm crtc
 *
 * Destroys the crtc state (both common and Intel-specific) for the
 * specified crtc.
 */
void
intel_crtc_destroy_state(struct drm_crtc *crtc,
                          struct drm_crtc_state *state)
{
        drm_atomic_helper_crtc_destroy_state(crtc, state);
}

/**
 * intel_atomic_setup_scalers() - setup scalers for crtc per staged requests
 * @dev: DRM device
 * @crtc: intel crtc
 * @crtc_state: incoming crtc_state to validate and setup scalers
 *
 * This function sets up scalers based on staged scaling requests for
 * a @crtc and its planes. It is called from crtc level check path. If request
 * is a supportable request, it attaches scalers to requested planes and crtc.
 *
 * This function takes into account the current scaler(s) in use by any planes
 * not being part of this atomic state
 *
 *  Returns:
 *         0 - scalers were setup succesfully
 *         error code - otherwise
 */
int intel_atomic_setup_scalers(struct drm_device *dev,
        struct intel_crtc *intel_crtc,
        struct intel_crtc_state *crtc_state)
{
        struct drm_plane *plane = NULL;
        struct intel_plane *intel_plane;
        struct intel_plane_state *plane_state = NULL;
        struct intel_crtc_scaler_state *scaler_state =
                &crtc_state->scaler_state;
        struct drm_atomic_state *drm_state = crtc_state->base.state;
        int num_scalers_need;
        int i, j;

        num_scalers_need = hweight32(scaler_state->scaler_users);

        /*
         * High level flow:
         * - staged scaler requests are already in scaler_state->scaler_users
         * - check whether staged scaling requests can be supported
         * - add planes using scalers that aren't in current transaction
         * - assign scalers to requested users
         * - as part of plane commit, scalers will be committed
         *   (i.e., either attached or detached) to respective planes in hw
         * - as part of crtc_commit, scaler will be either attached or detached
         *   to crtc in hw
         */

        /* fail if required scalers > available scalers */
        if (num_scalers_need > intel_crtc->num_scalers){
                DRM_DEBUG_KMS("Too many scaling requests %d > %d\n",
                        num_scalers_need, intel_crtc->num_scalers);
                return -EINVAL;
        }

        /* walkthrough scaler_users bits and start assigning scalers */
        for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
                int *scaler_id;
                const char *name;
                int idx;

                /* skip if scaler not required */
                if (!(scaler_state->scaler_users & (1 << i)))
                        continue;

                if (i == SKL_CRTC_INDEX) {
                        name = "CRTC";
                        idx = intel_crtc->base.base.id;

                        /* panel fitter case: assign as a crtc scaler */
                        scaler_id = &scaler_state->scaler_id;
                } else {
                        name = "PLANE";

                        /* plane scaler case: assign as a plane scaler */
                        /* find the plane that set the bit as scaler_user */
                        plane = drm_state->planes[i];

                        /*
                         * to enable/disable hq mode, add planes that are using scaler
                         * into this transaction
                         */
                        if (!plane) {
                                struct drm_plane_state *state;
                                plane = drm_plane_from_index(dev, i);
                                state = drm_atomic_get_plane_state(drm_state, plane);
                                if (IS_ERR(state)) {
                                        DRM_DEBUG_KMS("Failed to add [PLANE:%d] to drm_state\n",
                                                plane->base.id);
                                        return PTR_ERR(state);
                                }

                                /*
                                 * the plane is added after plane checks are run,
                                 * but since this plane is unchanged just do the
                                 * minimum required validation.
                                 */
                                crtc_state->base.planes_changed = true;
                        }

                        intel_plane = to_intel_plane(plane);
                        idx = plane->base.id;

                        /* plane on different crtc cannot be a scaler user of this crtc */
                        if (WARN_ON(intel_plane->pipe != intel_crtc->pipe)) {
                                continue;
                        }

                        plane_state = to_intel_plane_state(drm_state->plane_states[i]);
                        scaler_id = &plane_state->scaler_id;
                }

                if (*scaler_id < 0) {
                        /* find a free scaler */
                        for (j = 0; j < intel_crtc->num_scalers; j++) {
                                if (!scaler_state->scalers[j].in_use) {
                                        scaler_state->scalers[j].in_use = 1;
                                        *scaler_id = j;
                                        DRM_DEBUG_KMS("Attached scaler id %u.%u to %s:%d\n",
                                                intel_crtc->pipe, *scaler_id, name, idx);
                                        break;
                                }
                        }
                }

                if (WARN_ON(*scaler_id < 0)) {
                        DRM_DEBUG_KMS("Cannot find scaler for %s:%d\n", name, idx);
                        continue;
                }

                /* set scaler mode */
                if (num_scalers_need == 1 && intel_crtc->pipe != PIPE_C) {
                        /*
                         * when only 1 scaler is in use on either pipe A or B,
                         * scaler 0 operates in high quality (HQ) mode.
                         * In this case use scaler 0 to take advantage of HQ mode
                         */
                        *scaler_id = 0;
                        scaler_state->scalers[0].in_use = 1;
                        scaler_state->scalers[0].mode = PS_SCALER_MODE_HQ;
                        scaler_state->scalers[1].in_use = 0;
                } else {
                        scaler_state->scalers[*scaler_id].mode = PS_SCALER_MODE_DYN;
                }
        }

        return 0;
}

static void
intel_atomic_duplicate_dpll_state(struct drm_i915_private *dev_priv,
                                  struct intel_shared_dpll_config *shared_dpll)
{
        enum intel_dpll_id i;

        /* Copy shared dpll state */
        for (i = 0; i < dev_priv->num_shared_dpll; i++) {
                struct intel_shared_dpll *pll = &dev_priv->shared_dplls[i];

                shared_dpll[i] = pll->config;
        }
}

struct intel_shared_dpll_config *
intel_atomic_get_shared_dpll_state(struct drm_atomic_state *s)
{
        struct intel_atomic_state *state = to_intel_atomic_state(s);

        WARN_ON(!drm_modeset_is_locked(&s->dev->mode_config.connection_mutex));

        if (!state->dpll_set) {
                state->dpll_set = true;

                intel_atomic_duplicate_dpll_state(to_i915(s->dev),
                                                  state->shared_dpll);
        }

        return state->shared_dpll;
}

struct drm_atomic_state *
intel_atomic_state_alloc(struct drm_device *dev)
{
        struct intel_atomic_state *state = kzalloc(sizeof(*state), GFP_KERNEL);

        if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
                kfree(state);
                return NULL;
        }

        return &state->base;
}

void intel_atomic_state_clear(struct drm_atomic_state *s)
{
        struct intel_atomic_state *state = to_intel_atomic_state(s);
        drm_atomic_state_default_clear(&state->base);
        state->dpll_set = state->modeset = false;
}