/*
 * Copyright (c) 2016 MediaTek Inc.
 * Author: PC Chen <pc.chen@mediatek.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.
 */

#include <linux/module.h>
#include <linux/slab.h>

#include "../vdec_drv_if.h"
#include "../mtk_vcodec_util.h"
#include "../mtk_vcodec_dec.h"
#include "../mtk_vcodec_intr.h"
#include "../vdec_vpu_if.h"
#include "../vdec_drv_base.h"

#define NAL_NON_IDR_SLICE                       0x01
#define NAL_IDR_SLICE                           0x05
#define NAL_H264_PPS                            0x08
#define NAL_TYPE(value)                         ((value) & 0x1F)

#define BUF_PREDICTION_SZ                       (32 * 1024)

#define MB_UNIT_LEN                             16

/* motion vector size (bytes) for every macro block */
#define HW_MB_STORE_SZ                          64

#define H264_MAX_FB_NUM                         17
#define HDR_PARSING_BUF_SZ                      1024

/**
 * struct h264_fb - h264 decode frame buffer information
 * @vdec_fb_va  : virtual address of struct vdec_fb
 * @y_fb_dma    : dma address of Y frame buffer (luma)
 * @c_fb_dma    : dma address of C frame buffer (chroma)
 * @poc         : picture order count of frame buffer
 * @reserved    : for 8 bytes alignment
 */
struct h264_fb {
        uint64_t vdec_fb_va;
        uint64_t y_fb_dma;
        uint64_t c_fb_dma;
        int32_t poc;
        uint32_t reserved;
};

/**
 * struct h264_ring_fb_list - ring frame buffer list
 * @fb_list   : frame buffer arrary
 * @read_idx  : read index
 * @write_idx : write index
 * @count     : buffer count in list
 * @reserved  : for 8 bytes alignment
 */
struct h264_ring_fb_list {
        struct h264_fb fb_list[H264_MAX_FB_NUM];
        unsigned int read_idx;
        unsigned int write_idx;
        unsigned int count;
        unsigned int reserved;
};

/**
 * struct vdec_h264_dec_info - decode information
 * @dpb_sz              : decoding picture buffer size
 * @resolution_changed  : resoltion change happen
 * @realloc_mv_buf      : flag to notify driver to re-allocate mv buffer
 * @reserved            : for 8 bytes alignment
 * @bs_dma              : Input bit-stream buffer dma address
 * @y_fb_dma            : Y frame buffer dma address
 * @c_fb_dma            : C frame buffer dma address
 * @vdec_fb_va          : VDEC frame buffer struct virtual address
 */
struct vdec_h264_dec_info {
        uint32_t dpb_sz;
        uint32_t resolution_changed;
        uint32_t realloc_mv_buf;
        uint32_t reserved;
        uint64_t bs_dma;
        uint64_t y_fb_dma;
        uint64_t c_fb_dma;
        uint64_t vdec_fb_va;
};

/**
 * struct vdec_h264_vsi - shared memory for decode information exchange
 *                        between VPU and Host.
 *                        The memory is allocated by VPU then mapping to Host
 *                        in vpu_dec_init() and freed in vpu_dec_deinit()
 *                        by VPU.
 *                        AP-W/R : AP is writer/reader on this item
 *                        VPU-W/R: VPU is write/reader on this item
 * @hdr_buf      : Header parsing buffer (AP-W, VPU-R)
 * @pred_buf_dma : HW working predication buffer dma address (AP-W, VPU-R)
 * @mv_buf_dma   : HW working motion vector buffer dma address (AP-W, VPU-R)
 * @list_free    : free frame buffer ring list (AP-W/R, VPU-W)
 * @list_disp    : display frame buffer ring list (AP-R, VPU-W)
 * @dec          : decode information (AP-R, VPU-W)
 * @pic          : picture information (AP-R, VPU-W)
 * @crop         : crop information (AP-R, VPU-W)
 */
struct vdec_h264_vsi {
        unsigned char hdr_buf[HDR_PARSING_BUF_SZ];
        uint64_t pred_buf_dma;
        uint64_t mv_buf_dma[H264_MAX_FB_NUM];
        struct h264_ring_fb_list list_free;
        struct h264_ring_fb_list list_disp;
        struct vdec_h264_dec_info dec;
        struct vdec_pic_info pic;
        struct v4l2_rect crop;
};

/**
 * struct vdec_h264_inst - h264 decoder instance
 * @num_nalu : how many nalus be decoded
 * @ctx      : point to mtk_vcodec_ctx
 * @pred_buf : HW working predication buffer
 * @mv_buf   : HW working motion vector buffer
 * @vpu      : VPU instance
 * @vsi      : VPU shared information
 */
struct vdec_h264_inst {
        unsigned int num_nalu;
        struct mtk_vcodec_ctx *ctx;
        struct mtk_vcodec_mem pred_buf;
        struct mtk_vcodec_mem mv_buf[H264_MAX_FB_NUM];
        struct vdec_vpu_inst vpu;
        struct vdec_h264_vsi *vsi;
};

static unsigned int get_mv_buf_size(unsigned int width, unsigned int height)
{
        return HW_MB_STORE_SZ * (width/MB_UNIT_LEN) * (height/MB_UNIT_LEN);
}

static int allocate_predication_buf(struct vdec_h264_inst *inst)
{
        int err = 0;

        inst->pred_buf.size = BUF_PREDICTION_SZ;
        err = mtk_vcodec_mem_alloc(inst->ctx, &inst->pred_buf);
        if (err) {
                mtk_vcodec_err(inst, "failed to allocate ppl buf");
                return err;
        }

        inst->vsi->pred_buf_dma = inst->pred_buf.dma_addr;
        return 0;
}

static void free_predication_buf(struct vdec_h264_inst *inst)
{
        struct mtk_vcodec_mem *mem = NULL;

        mtk_vcodec_debug_enter(inst);

        inst->vsi->pred_buf_dma = 0;
        mem = &inst->pred_buf;
        if (mem->va)
                mtk_vcodec_mem_free(inst->ctx, mem);
}

static int alloc_mv_buf(struct vdec_h264_inst *inst, struct vdec_pic_info *pic)
{
        int i;
        int err;
        struct mtk_vcodec_mem *mem = NULL;
        unsigned int buf_sz = get_mv_buf_size(pic->buf_w, pic->buf_h);

        for (i = 0; i < H264_MAX_FB_NUM; i++) {
                mem = &inst->mv_buf[i];
                if (mem->va)
                        mtk_vcodec_mem_free(inst->ctx, mem);
                mem->size = buf_sz;
                err = mtk_vcodec_mem_alloc(inst->ctx, mem);
                if (err) {
                        mtk_vcodec_err(inst, "failed to allocate mv buf");
                        return err;
                }
                inst->vsi->mv_buf_dma[i] = mem->dma_addr;
        }

        return 0;
}

static void free_mv_buf(struct vdec_h264_inst *inst)
{
        int i;
        struct mtk_vcodec_mem *mem = NULL;

        for (i = 0; i < H264_MAX_FB_NUM; i++) {
                inst->vsi->mv_buf_dma[i] = 0;
                mem = &inst->mv_buf[i];
                if (mem->va)
                        mtk_vcodec_mem_free(inst->ctx, mem);
        }
}

static int check_list_validity(struct vdec_h264_inst *inst, bool disp_list)
{
        struct h264_ring_fb_list *list;

        list = disp_list ? &inst->vsi->list_disp : &inst->vsi->list_free;

        if (list->count > H264_MAX_FB_NUM ||
            list->read_idx >= H264_MAX_FB_NUM ||
            list->write_idx >= H264_MAX_FB_NUM) {
                mtk_vcodec_err(inst, "%s list err: cnt=%d r_idx=%d w_idx=%d",
                               disp_list ? "disp" : "free", list->count,
                               list->read_idx, list->write_idx);
                return -EINVAL;
        }

        return 0;
}

static void put_fb_to_free(struct vdec_h264_inst *inst, struct vdec_fb *fb)
{
        struct h264_ring_fb_list *list;

        if (fb) {
                if (check_list_validity(inst, false))
                        return;

                list = &inst->vsi->list_free;
                if (list->count == H264_MAX_FB_NUM) {
                        mtk_vcodec_err(inst, "[FB] put fb free_list full");
                        return;
                }

                mtk_vcodec_debug(inst, "[FB] put fb into free_list @(%p, %llx)",
                                 fb->base_y.va, (u64)fb->base_y.dma_addr);

                list->fb_list[list->write_idx].vdec_fb_va = (u64)(uintptr_t)fb;
                list->write_idx = (list->write_idx == H264_MAX_FB_NUM - 1) ?
                                  0 : list->write_idx + 1;
                list->count++;
        }
}

static void get_pic_info(struct vdec_h264_inst *inst,
                         struct vdec_pic_info *pic)
{
        *pic = inst->vsi->pic;
        mtk_vcodec_debug(inst, "pic(%d, %d), buf(%d, %d)",
                         pic->pic_w, pic->pic_h, pic->buf_w, pic->buf_h);
        mtk_vcodec_debug(inst, "Y(%d, %d), C(%d, %d)", pic->y_bs_sz,
                         pic->y_len_sz, pic->c_bs_sz, pic->c_len_sz);
}

static void get_crop_info(struct vdec_h264_inst *inst, struct v4l2_rect *cr)
{
        cr->left = inst->vsi->crop.left;
        cr->top = inst->vsi->crop.top;
        cr->width = inst->vsi->crop.width;
        cr->height = inst->vsi->crop.height;

        mtk_vcodec_debug(inst, "l=%d, t=%d, w=%d, h=%d",
                         cr->left, cr->top, cr->width, cr->height);
}

static void get_dpb_size(struct vdec_h264_inst *inst, unsigned int *dpb_sz)
{
        *dpb_sz = inst->vsi->dec.dpb_sz;
        mtk_vcodec_debug(inst, "sz=%d", *dpb_sz);
}

static int vdec_h264_init(struct mtk_vcodec_ctx *ctx, unsigned long *h_vdec)
{
        struct vdec_h264_inst *inst = NULL;
        int err;

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

        inst->ctx = ctx;

        inst->vpu.id = IPI_VDEC_H264;
        inst->vpu.dev = ctx->dev->vpu_plat_dev;
        inst->vpu.ctx = ctx;
        inst->vpu.handler = vpu_dec_ipi_handler;

        err = vpu_dec_init(&inst->vpu);
        if (err) {
                mtk_vcodec_err(inst, "vdec_h264 init err=%d", err);
                goto error_free_inst;
        }

        inst->vsi = (struct vdec_h264_vsi *)inst->vpu.vsi;
        err = allocate_predication_buf(inst);
        if (err)
                goto error_deinit;

        mtk_vcodec_debug(inst, "H264 Instance >> %p", inst);

        *h_vdec = (unsigned long)inst;
        return 0;

error_deinit:
        vpu_dec_deinit(&inst->vpu);

error_free_inst:
        kfree(inst);
        return err;
}

static void vdec_h264_deinit(unsigned long h_vdec)
{
        struct vdec_h264_inst *inst = (struct vdec_h264_inst *)h_vdec;

        mtk_vcodec_debug_enter(inst);

        vpu_dec_deinit(&inst->vpu);
        free_predication_buf(inst);
        free_mv_buf(inst);

        kfree(inst);
}

static int find_start_code(unsigned char *data, unsigned int data_sz)
{
        if (data_sz > 3 && data[0] == 0 && data[1] == 0 && data[2] == 1)
                return 3;

        if (data_sz > 4 && data[0] == 0 && data[1] == 0 && data[2] == 0 &&
            data[3] == 1)
                return 4;

        return -1;
}

static int vdec_h264_decode(unsigned long h_vdec, struct mtk_vcodec_mem *bs,
                            struct vdec_fb *fb, bool *res_chg)
{
        struct vdec_h264_inst *inst = (struct vdec_h264_inst *)h_vdec;
        struct vdec_vpu_inst *vpu = &inst->vpu;
        int nal_start_idx = 0;
        int err = 0;
        unsigned int nal_start;
        unsigned int nal_type;
        unsigned char *buf;
        unsigned int buf_sz;
        unsigned int data[2];
        uint64_t vdec_fb_va = (u64)(uintptr_t)fb;
        uint64_t y_fb_dma = fb ? (u64)fb->base_y.dma_addr : 0;
        uint64_t c_fb_dma = fb ? (u64)fb->base_c.dma_addr : 0;

        mtk_vcodec_debug(inst, "+ [%d] FB y_dma=%llx c_dma=%llx va=%p",
                         ++inst->num_nalu, y_fb_dma, c_fb_dma, fb);

        /* bs NULL means flush decoder */
        if (bs == NULL)
                return vpu_dec_reset(vpu);

        buf = (unsigned char *)bs->va;
        buf_sz = bs->size;
        nal_start_idx = find_start_code(buf, buf_sz);
        if (nal_start_idx < 0)
                goto err_free_fb_out;

        nal_start = buf[nal_start_idx];
        nal_type = NAL_TYPE(buf[nal_start_idx]);
        mtk_vcodec_debug(inst, "\n + NALU[%d] type %d +\n", inst->num_nalu,
                         nal_type);

        if (nal_type == NAL_H264_PPS) {
                buf_sz -= nal_start_idx;
                if (buf_sz > HDR_PARSING_BUF_SZ) {
                        err = -EILSEQ;
                        goto err_free_fb_out;
                }
                memcpy(inst->vsi->hdr_buf, buf + nal_start_idx, buf_sz);
        }

        inst->vsi->dec.bs_dma = (uint64_t)bs->dma_addr;
        inst->vsi->dec.y_fb_dma = y_fb_dma;
        inst->vsi->dec.c_fb_dma = c_fb_dma;
        inst->vsi->dec.vdec_fb_va = vdec_fb_va;

        data[0] = buf_sz;
        data[1] = nal_start;
        err = vpu_dec_start(vpu, data, 2);
        if (err)
                goto err_free_fb_out;

        *res_chg = inst->vsi->dec.resolution_changed;
        if (*res_chg) {
                struct vdec_pic_info pic;

                mtk_vcodec_debug(inst, "- resolution changed -");
                get_pic_info(inst, &pic);

                if (inst->vsi->dec.realloc_mv_buf) {
                        err = alloc_mv_buf(inst, &pic);
                        if (err)
                                goto err_free_fb_out;
                }
        }

        if (nal_type == NAL_NON_IDR_SLICE || nal_type == NAL_IDR_SLICE) {
                /* wait decoder done interrupt */
                err = mtk_vcodec_wait_for_done_ctx(inst->ctx,
                                                   MTK_INST_IRQ_RECEIVED,
                                                   WAIT_INTR_TIMEOUT_MS);
                if (err)
                        goto err_free_fb_out;

                vpu_dec_end(vpu);
        }

        mtk_vcodec_debug(inst, "\n - NALU[%d] type=%d -\n", inst->num_nalu,
                         nal_type);
        return 0;

err_free_fb_out:
        put_fb_to_free(inst, fb);
        mtk_vcodec_err(inst, "\n - NALU[%d] err=%d -\n", inst->num_nalu, err);
        return err;
}

static void vdec_h264_get_fb(struct vdec_h264_inst *inst,
                             struct h264_ring_fb_list *list,
                             bool disp_list, struct vdec_fb **out_fb)
{
        struct vdec_fb *fb;

        if (check_list_validity(inst, disp_list))
                return;

        if (list->count == 0) {
                mtk_vcodec_debug(inst, "[FB] there is no %s fb",
                                 disp_list ? "disp" : "free");
                *out_fb = NULL;
                return;
        }

        fb = (struct vdec_fb *)
                (uintptr_t)list->fb_list[list->read_idx].vdec_fb_va;
        fb->status |= (disp_list ? FB_ST_DISPLAY : FB_ST_FREE);

        *out_fb = fb;
        mtk_vcodec_debug(inst, "[FB] get %s fb st=%d poc=%d %llx",
                         disp_list ? "disp" : "free",
                         fb->status, list->fb_list[list->read_idx].poc,
                         list->fb_list[list->read_idx].vdec_fb_va);

        list->read_idx = (list->read_idx == H264_MAX_FB_NUM - 1) ?
                         0 : list->read_idx + 1;
        list->count--;
}

static int vdec_h264_get_param(unsigned long h_vdec,
                               enum vdec_get_param_type type, void *out)
{
        struct vdec_h264_inst *inst = (struct vdec_h264_inst *)h_vdec;

        switch (type) {
        case GET_PARAM_DISP_FRAME_BUFFER:
                vdec_h264_get_fb(inst, &inst->vsi->list_disp, true, out);
                break;

        case GET_PARAM_FREE_FRAME_BUFFER:
                vdec_h264_get_fb(inst, &inst->vsi->list_free, false, out);
                break;

        case GET_PARAM_PIC_INFO:
                get_pic_info(inst, out);
                break;

        case GET_PARAM_DPB_SIZE:
                get_dpb_size(inst, out);
                break;

        case GET_PARAM_CROP_INFO:
                get_crop_info(inst, out);
                break;

        default:
                mtk_vcodec_err(inst, "invalid get parameter type=%d", type);
                return -EINVAL;
        }

        return 0;
}

static struct vdec_common_if vdec_h264_if = {
        .init           = vdec_h264_init,
        .decode         = vdec_h264_decode,
        .get_param      = vdec_h264_get_param,
        .deinit         = vdec_h264_deinit,
};

struct vdec_common_if *get_h264_dec_comm_if(void);

struct vdec_common_if *get_h264_dec_comm_if(void)
{
        return &vdec_h264_if;
}