/*
 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
 * Author: Liviu Dudau <Liviu.Dudau@arm.com>
 *
 * This program is free software and is provided to you under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation, and any use by you of this program is subject to the terms
 * of such GNU licence.
 *
 * ARM Mali DP500/DP550/DP650 driver (crtc operations)
 */

#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <video/videomode.h>

#include "malidp_drv.h"
#include "malidp_hw.h"

static enum drm_mode_status malidp_crtc_mode_valid(struct drm_crtc *crtc,
                                                   const struct drm_display_mode *mode)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;

        /*
         * check that the hardware can drive the required clock rate,
         * but skip the check if the clock is meant to be disabled (req_rate = 0)
         */
        long rate, req_rate = mode->crtc_clock * 1000;

        if (req_rate) {
                rate = clk_round_rate(hwdev->pxlclk, req_rate);
                if (rate != req_rate) {
                        DRM_DEBUG_DRIVER("pxlclk doesn't support %ld Hz\n",
                                         req_rate);
                        return MODE_NOCLOCK;
                }
        }

        return MODE_OK;
}

static void malidp_crtc_atomic_enable(struct drm_crtc *crtc,
                                      struct drm_crtc_state *old_state)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;
        struct videomode vm;
        int err = pm_runtime_get_sync(crtc->dev->dev);

        if (err < 0) {
                DRM_DEBUG_DRIVER("Failed to enable runtime power management: %d\n", err);
                return;
        }

        drm_display_mode_to_videomode(&crtc->state->adjusted_mode, &vm);
        clk_prepare_enable(hwdev->pxlclk);

        /* We rely on firmware to set mclk to a sensible level. */
        clk_set_rate(hwdev->pxlclk, crtc->state->adjusted_mode.crtc_clock * 1000);

        hwdev->hw->modeset(hwdev, &vm);
        hwdev->hw->leave_config_mode(hwdev);
        drm_crtc_vblank_on(crtc);
}

static void malidp_crtc_atomic_disable(struct drm_crtc *crtc,
                                       struct drm_crtc_state *old_state)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;
        int err;

        /* always disable planes on the CRTC that is being turned off */
        drm_atomic_helper_disable_planes_on_crtc(old_state, false);

        drm_crtc_vblank_off(crtc);
        hwdev->hw->enter_config_mode(hwdev);

        clk_disable_unprepare(hwdev->pxlclk);

        err = pm_runtime_put(crtc->dev->dev);
        if (err < 0) {
                DRM_DEBUG_DRIVER("Failed to disable runtime power management: %d\n", err);
        }
}

static const struct gamma_curve_segment {
        u16 start;
        u16 end;
} segments[MALIDP_COEFFTAB_NUM_COEFFS] = {
        /* sector 0 */
        {    0,    0 }, {    1,    1 }, {    2,    2 }, {    3,    3 },
        {    4,    4 }, {    5,    5 }, {    6,    6 }, {    7,    7 },
        {    8,    8 }, {    9,    9 }, {   10,   10 }, {   11,   11 },
        {   12,   12 }, {   13,   13 }, {   14,   14 }, {   15,   15 },
        /* sector 1 */
        {   16,   19 }, {   20,   23 }, {   24,   27 }, {   28,   31 },
        /* sector 2 */
        {   32,   39 }, {   40,   47 }, {   48,   55 }, {   56,   63 },
        /* sector 3 */
        {   64,   79 }, {   80,   95 }, {   96,  111 }, {  112,  127 },
        /* sector 4 */
        {  128,  159 }, {  160,  191 }, {  192,  223 }, {  224,  255 },
        /* sector 5 */
        {  256,  319 }, {  320,  383 }, {  384,  447 }, {  448,  511 },
        /* sector 6 */
        {  512,  639 }, {  640,  767 }, {  768,  895 }, {  896, 1023 },
        { 1024, 1151 }, { 1152, 1279 }, { 1280, 1407 }, { 1408, 1535 },
        { 1536, 1663 }, { 1664, 1791 }, { 1792, 1919 }, { 1920, 2047 },
        { 2048, 2175 }, { 2176, 2303 }, { 2304, 2431 }, { 2432, 2559 },
        { 2560, 2687 }, { 2688, 2815 }, { 2816, 2943 }, { 2944, 3071 },
        { 3072, 3199 }, { 3200, 3327 }, { 3328, 3455 }, { 3456, 3583 },
        { 3584, 3711 }, { 3712, 3839 }, { 3840, 3967 }, { 3968, 4095 },
};

#define DE_COEFTAB_DATA(a, b) ((((a) & 0xfff) << 16) | (((b) & 0xfff)))

static void malidp_generate_gamma_table(struct drm_property_blob *lut_blob,
                                        u32 coeffs[MALIDP_COEFFTAB_NUM_COEFFS])
{
        struct drm_color_lut *lut = (struct drm_color_lut *)lut_blob->data;
        int i;

        for (i = 0; i < MALIDP_COEFFTAB_NUM_COEFFS; ++i) {
                u32 a, b, delta_in, out_start, out_end;

                delta_in = segments[i].end - segments[i].start;
                /* DP has 12-bit internal precision for its LUTs. */
                out_start = drm_color_lut_extract(lut[segments[i].start].green,
                                                  12);
                out_end = drm_color_lut_extract(lut[segments[i].end].green, 12);
                a = (delta_in == 0) ? 0 : ((out_end - out_start) * 256) / delta_in;
                b = out_start;
                coeffs[i] = DE_COEFTAB_DATA(a, b);
        }
}

/*
 * Check if there is a new gamma LUT and if it is of an acceptable size. Also,
 * reject any LUTs that use distinct red, green, and blue curves.
 */
static int malidp_crtc_atomic_check_gamma(struct drm_crtc *crtc,
                                          struct drm_crtc_state *state)
{
        struct malidp_crtc_state *mc = to_malidp_crtc_state(state);
        struct drm_color_lut *lut;
        size_t lut_size;
        int i;

        if (!state->color_mgmt_changed || !state->gamma_lut)
                return 0;

        if (crtc->state->gamma_lut &&
            (crtc->state->gamma_lut->base.id == state->gamma_lut->base.id))
                return 0;

        if (state->gamma_lut->length % sizeof(struct drm_color_lut))
                return -EINVAL;

        lut_size = state->gamma_lut->length / sizeof(struct drm_color_lut);
        if (lut_size != MALIDP_GAMMA_LUT_SIZE)
                return -EINVAL;

        lut = (struct drm_color_lut *)state->gamma_lut->data;
        for (i = 0; i < lut_size; ++i)
                if (!((lut[i].red == lut[i].green) &&
                      (lut[i].red == lut[i].blue)))
                        return -EINVAL;

        if (!state->mode_changed) {
                int ret;

                state->mode_changed = true;
                /*
                 * Kerneldoc for drm_atomic_helper_check_modeset mandates that
                 * it be invoked when the driver sets ->mode_changed. Since
                 * changing the gamma LUT doesn't depend on any external
                 * resources, it is safe to call it only once.
                 */
                ret = drm_atomic_helper_check_modeset(crtc->dev, state->state);
                if (ret)
                        return ret;
        }

        malidp_generate_gamma_table(state->gamma_lut, mc->gamma_coeffs);
        return 0;
}

/*
 * Check if there is a new CTM and if it contains valid input. Valid here means
 * that the number is inside the representable range for a Q3.12 number,
 * excluding truncating the fractional part of the input data.
 *
 * The COLORADJ registers can be changed atomically.
 */
static int malidp_crtc_atomic_check_ctm(struct drm_crtc *crtc,
                                        struct drm_crtc_state *state)
{
        struct malidp_crtc_state *mc = to_malidp_crtc_state(state);
        struct drm_color_ctm *ctm;
        int i;

        if (!state->color_mgmt_changed)
                return 0;

        if (!state->ctm)
                return 0;

        if (crtc->state->ctm && (crtc->state->ctm->base.id ==
                                 state->ctm->base.id))
                return 0;

        /*
         * The size of the ctm is checked in
         * drm_atomic_replace_property_blob_from_id.
         */
        ctm = (struct drm_color_ctm *)state->ctm->data;
        for (i = 0; i < ARRAY_SIZE(ctm->matrix); ++i) {
                /* Convert from S31.32 to Q3.12. */
                s64 val = ctm->matrix[i];
                u32 mag = ((((u64)val) & ~BIT_ULL(63)) >> 20) &
                          GENMASK_ULL(14, 0);

                /*
                 * Convert to 2s complement and check the destination's top bit
                 * for overflow. NB: Can't check before converting or it'd
                 * incorrectly reject the case:
                 * sign == 1
                 * mag == 0x2000
                 */
                if (val & BIT_ULL(63))
                        mag = ~mag + 1;
                if (!!(val & BIT_ULL(63)) != !!(mag & BIT(14)))
                        return -EINVAL;
                mc->coloradj_coeffs[i] = mag;
        }

        return 0;
}

static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
                                            struct drm_crtc_state *state)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;
        struct malidp_crtc_state *cs = to_malidp_crtc_state(state);
        struct malidp_se_config *s = &cs->scaler_config;
        struct drm_plane *plane;
        struct videomode vm;
        const struct drm_plane_state *pstate;
        u32 h_upscale_factor = 0; /* U16.16 */
        u32 v_upscale_factor = 0; /* U16.16 */
        u8 scaling = cs->scaled_planes_mask;
        int ret;

        if (!scaling) {
                s->scale_enable = false;
                goto mclk_calc;
        }

        /* The scaling engine can only handle one plane at a time. */
        if (scaling & (scaling - 1))
                return -EINVAL;

        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
                struct malidp_plane *mp = to_malidp_plane(plane);
                u32 phase;

                if (!(mp->layer->id & scaling))
                        continue;

                /*
                 * Convert crtc_[w|h] to U32.32, then divide by U16.16 src_[w|h]
                 * to get the U16.16 result.
                 */
                h_upscale_factor = div_u64((u64)pstate->crtc_w << 32,
                                           pstate->src_w);
                v_upscale_factor = div_u64((u64)pstate->crtc_h << 32,
                                           pstate->src_h);

                s->enhancer_enable = ((h_upscale_factor >> 16) >= 2 ||
                                      (v_upscale_factor >> 16) >= 2);

                if (pstate->rotation & MALIDP_ROTATED_MASK) {
                        s->input_w = pstate->src_h >> 16;
                        s->input_h = pstate->src_w >> 16;
                } else {
                        s->input_w = pstate->src_w >> 16;
                        s->input_h = pstate->src_h >> 16;
                }

                s->output_w = pstate->crtc_w;
                s->output_h = pstate->crtc_h;

#define SE_N_PHASE 4
#define SE_SHIFT_N_PHASE 12
                /* Calculate initial_phase and delta_phase for horizontal. */
                phase = s->input_w;
                s->h_init_phase =
                                ((phase << SE_N_PHASE) / s->output_w + 1) / 2;

                phase = s->input_w;
                phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
                s->h_delta_phase = phase / s->output_w;

                /* Same for vertical. */
                phase = s->input_h;
                s->v_init_phase =
                                ((phase << SE_N_PHASE) / s->output_h + 1) / 2;

                phase = s->input_h;
                phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
                s->v_delta_phase = phase / s->output_h;
#undef SE_N_PHASE
#undef SE_SHIFT_N_PHASE
                s->plane_src_id = mp->layer->id;
        }

        s->scale_enable = true;
        s->hcoeff = malidp_se_select_coeffs(h_upscale_factor);
        s->vcoeff = malidp_se_select_coeffs(v_upscale_factor);

mclk_calc:
        drm_display_mode_to_videomode(&state->adjusted_mode, &vm);
        ret = hwdev->hw->se_calc_mclk(hwdev, s, &vm);
        if (ret < 0)
                return -EINVAL;
        return 0;
}

static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
                                    struct drm_crtc_state *state)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;
        struct drm_plane *plane;
        const struct drm_plane_state *pstate;
        u32 rot_mem_free, rot_mem_usable;
        int rotated_planes = 0;
        int ret;

        /*
         * check if there is enough rotation memory available for planes
         * that need 90° and 270° rotation. Each plane has set its required
         * memory size in the ->plane_check() callback, here we only make
         * sure that the sums are less that the total usable memory.
         *
         * The rotation memory allocation algorithm (for each plane):
         *  a. If no more rotated planes exist, all remaining rotate
         *     memory in the bank is available for use by the plane.
         *  b. If other rotated planes exist, and plane's layer ID is
         *     DE_VIDEO1, it can use all the memory from first bank if
         *     secondary rotation memory bank is available, otherwise it can
         *     use up to half the bank's memory.
         *  c. If other rotated planes exist, and plane's layer ID is not
         *     DE_VIDEO1, it can use half of the available memory
         *
         * Note: this algorithm assumes that the order in which the planes are
         * checked always has DE_VIDEO1 plane first in the list if it is
         * rotated. Because that is how we create the planes in the first
         * place, under current DRM version things work, but if ever the order
         * in which drm_atomic_crtc_state_for_each_plane() iterates over planes
         * changes, we need to pre-sort the planes before validation.
         */

        /* first count the number of rotated planes */
        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
                if (pstate->rotation & MALIDP_ROTATED_MASK)
                        rotated_planes++;
        }

        rot_mem_free = hwdev->rotation_memory[0];
        /*
         * if we have more than 1 plane using rotation memory, use the second
         * block of rotation memory as well
         */
        if (rotated_planes > 1)
                rot_mem_free += hwdev->rotation_memory[1];

        /* now validate the rotation memory requirements */
        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
                struct malidp_plane *mp = to_malidp_plane(plane);
                struct malidp_plane_state *ms = to_malidp_plane_state(pstate);

                if (pstate->rotation & MALIDP_ROTATED_MASK) {
                        /* process current plane */
                        rotated_planes--;

                        if (!rotated_planes) {
                                /* no more rotated planes, we can use what's left */
                                rot_mem_usable = rot_mem_free;
                        } else {
                                if ((mp->layer->id != DE_VIDEO1) ||
                                    (hwdev->rotation_memory[1] == 0))
                                        rot_mem_usable = rot_mem_free / 2;
                                else
                                        rot_mem_usable = hwdev->rotation_memory[0];
                        }

                        rot_mem_free -= rot_mem_usable;

                        if (ms->rotmem_size > rot_mem_usable)
                                return -EINVAL;
                }
        }

        /* If only the writeback routing has changed, we don't need a modeset */
        if (state->connectors_changed) {
                u32 old_mask = crtc->state->connector_mask;
                u32 new_mask = state->connector_mask;

                if ((old_mask ^ new_mask) ==
                    (1 << drm_connector_index(&malidp->mw_connector.base)))
                        state->connectors_changed = false;
        }

        ret = malidp_crtc_atomic_check_gamma(crtc, state);
        ret = ret ? ret : malidp_crtc_atomic_check_ctm(crtc, state);
        ret = ret ? ret : malidp_crtc_atomic_check_scaling(crtc, state);

        return ret;
}

static const struct drm_crtc_helper_funcs malidp_crtc_helper_funcs = {
        .mode_valid = malidp_crtc_mode_valid,
        .atomic_check = malidp_crtc_atomic_check,
        .atomic_enable = malidp_crtc_atomic_enable,
        .atomic_disable = malidp_crtc_atomic_disable,
};

static struct drm_crtc_state *malidp_crtc_duplicate_state(struct drm_crtc *crtc)
{
        struct malidp_crtc_state *state, *old_state;

        if (WARN_ON(!crtc->state))
                return NULL;

        old_state = to_malidp_crtc_state(crtc->state);
        state = kmalloc(sizeof(*state), GFP_KERNEL);
        if (!state)
                return NULL;

        __drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
        memcpy(state->gamma_coeffs, old_state->gamma_coeffs,
               sizeof(state->gamma_coeffs));
        memcpy(state->coloradj_coeffs, old_state->coloradj_coeffs,
               sizeof(state->coloradj_coeffs));
        memcpy(&state->scaler_config, &old_state->scaler_config,
               sizeof(state->scaler_config));
        state->scaled_planes_mask = 0;

        return &state->base;
}

static void malidp_crtc_reset(struct drm_crtc *crtc)
{
        struct malidp_crtc_state *state = NULL;

        if (crtc->state) {
                state = to_malidp_crtc_state(crtc->state);
                __drm_atomic_helper_crtc_destroy_state(crtc->state);
        }

        kfree(state);
        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (state) {
                crtc->state = &state->base;
                crtc->state->crtc = crtc;
        }
}

static void malidp_crtc_destroy_state(struct drm_crtc *crtc,
                                      struct drm_crtc_state *state)
{
        struct malidp_crtc_state *mali_state = NULL;

        if (state) {
                mali_state = to_malidp_crtc_state(state);
                __drm_atomic_helper_crtc_destroy_state(state);
        }

        kfree(mali_state);
}

static int malidp_crtc_enable_vblank(struct drm_crtc *crtc)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;

        malidp_hw_enable_irq(hwdev, MALIDP_DE_BLOCK,
                             hwdev->hw->map.de_irq_map.vsync_irq);
        return 0;
}

static void malidp_crtc_disable_vblank(struct drm_crtc *crtc)
{
        struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
        struct malidp_hw_device *hwdev = malidp->dev;

        malidp_hw_disable_irq(hwdev, MALIDP_DE_BLOCK,
                              hwdev->hw->map.de_irq_map.vsync_irq);
}

static const struct drm_crtc_funcs malidp_crtc_funcs = {
        .gamma_set = drm_atomic_helper_legacy_gamma_set,
        .destroy = drm_crtc_cleanup,
        .set_config = drm_atomic_helper_set_config,
        .page_flip = drm_atomic_helper_page_flip,
        .reset = malidp_crtc_reset,
        .atomic_duplicate_state = malidp_crtc_duplicate_state,
        .atomic_destroy_state = malidp_crtc_destroy_state,
        .enable_vblank = malidp_crtc_enable_vblank,
        .disable_vblank = malidp_crtc_disable_vblank,
};

int malidp_crtc_init(struct drm_device *drm)
{
        struct malidp_drm *malidp = drm->dev_private;
        struct drm_plane *primary = NULL, *plane;
        int ret;

        ret = malidp_de_planes_init(drm);
        if (ret < 0) {
                DRM_ERROR("Failed to initialise planes\n");
                return ret;
        }

        drm_for_each_plane(plane, drm) {
                if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
                        primary = plane;
                        break;
                }
        }

        if (!primary) {
                DRM_ERROR("no primary plane found\n");
                return -EINVAL;
        }

        ret = drm_crtc_init_with_planes(drm, &malidp->crtc, primary, NULL,
                                        &malidp_crtc_funcs, NULL);
        if (ret)
                return ret;

        drm_crtc_helper_add(&malidp->crtc, &malidp_crtc_helper_funcs);
        drm_mode_crtc_set_gamma_size(&malidp->crtc, MALIDP_GAMMA_LUT_SIZE);
        /* No inverse-gamma: it is per-plane. */
        drm_crtc_enable_color_mgmt(&malidp->crtc, 0, true, MALIDP_GAMMA_LUT_SIZE);

        malidp_se_set_enh_coeffs(malidp->dev);

        return 0;
}