// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 BayLibre, SAS
 * Author: Maxime Jourdan <mjourdan@baylibre.com>
 *
 * The Elementary Stream Parser is a HW bitstream parser.
 * It reads bitstream buffers and feeds them to the VIFIFO
 */

#include <linux/init.h>
#include <linux/ioctl.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/reset.h>
#include <linux/interrupt.h>
#include <media/videobuf2-dma-contig.h>
#include <media/v4l2-mem2mem.h>

#include "dos_regs.h"
#include "esparser.h"
#include "vdec_helpers.h"

/* PARSER REGS (CBUS) */
#define PARSER_CONTROL 0x00
        #define ES_PACK_SIZE_BIT        8
        #define ES_WRITE                BIT(5)
        #define ES_SEARCH               BIT(1)
        #define ES_PARSER_START         BIT(0)
#define PARSER_FETCH_ADDR       0x4
#define PARSER_FETCH_CMD        0x8
#define PARSER_CONFIG 0x14
        #define PS_CFG_MAX_FETCH_CYCLE_BIT      0
        #define PS_CFG_STARTCODE_WID_24_BIT     10
        #define PS_CFG_MAX_ES_WR_CYCLE_BIT      12
        #define PS_CFG_PFIFO_EMPTY_CNT_BIT      16
#define PFIFO_WR_PTR 0x18
#define PFIFO_RD_PTR 0x1c
#define PARSER_SEARCH_PATTERN 0x24
        #define ES_START_CODE_PATTERN 0x00000100
#define PARSER_SEARCH_MASK 0x28
        #define ES_START_CODE_MASK      0xffffff00
        #define FETCH_ENDIAN_BIT        27
#define PARSER_INT_ENABLE       0x2c
        #define PARSER_INT_HOST_EN_BIT  8
#define PARSER_INT_STATUS       0x30
        #define PARSER_INTSTAT_SC_FOUND 1
#define PARSER_ES_CONTROL       0x5c
#define PARSER_VIDEO_START_PTR  0x80
#define PARSER_VIDEO_END_PTR    0x84
#define PARSER_VIDEO_WP         0x88
#define PARSER_VIDEO_HOLE       0x90

#define SEARCH_PATTERN_LEN      512
#define VP9_HEADER_SIZE         16

static DECLARE_WAIT_QUEUE_HEAD(wq);
static int search_done;

static irqreturn_t esparser_isr(int irq, void *dev)
{
        int int_status;
        struct amvdec_core *core = dev;

        int_status = amvdec_read_parser(core, PARSER_INT_STATUS);
        amvdec_write_parser(core, PARSER_INT_STATUS, int_status);

        if (int_status & PARSER_INTSTAT_SC_FOUND) {
                amvdec_write_parser(core, PFIFO_RD_PTR, 0);
                amvdec_write_parser(core, PFIFO_WR_PTR, 0);
                search_done = 1;
                wake_up_interruptible(&wq);
        }

        return IRQ_HANDLED;
}

/*
 * VP9 frame headers need to be appended by a 16-byte long
 * Amlogic custom header
 */
static int vp9_update_header(struct amvdec_core *core, struct vb2_buffer *buf)
{
        u8 *dp;
        u8 marker;
        int dsize;
        int num_frames, cur_frame;
        int cur_mag, mag, mag_ptr;
        int frame_size[8], tot_frame_size[8];
        int total_datasize = 0;
        int new_frame_size;
        unsigned char *old_header = NULL;

        dp = (uint8_t *)vb2_plane_vaddr(buf, 0);
        dsize = vb2_get_plane_payload(buf, 0);

        if (dsize == vb2_plane_size(buf, 0)) {
                dev_warn(core->dev, "%s: unable to update header\n", __func__);
                return 0;
        }

        marker = dp[dsize - 1];
        if ((marker & 0xe0) == 0xc0) {
                num_frames = (marker & 0x7) + 1;
                mag = ((marker >> 3) & 0x3) + 1;
                mag_ptr = dsize - mag * num_frames - 2;
                if (dp[mag_ptr] != marker)
                        return 0;

                mag_ptr++;
                for (cur_frame = 0; cur_frame < num_frames; cur_frame++) {
                        frame_size[cur_frame] = 0;
                        for (cur_mag = 0; cur_mag < mag; cur_mag++) {
                                frame_size[cur_frame] |=
                                        (dp[mag_ptr] << (cur_mag * 8));
                                mag_ptr++;
                        }
                        if (cur_frame == 0)
                                tot_frame_size[cur_frame] =
                                        frame_size[cur_frame];
                        else
                                tot_frame_size[cur_frame] =
                                        tot_frame_size[cur_frame - 1] +
                                        frame_size[cur_frame];
                        total_datasize += frame_size[cur_frame];
                }
        } else {
                num_frames = 1;
                frame_size[0] = dsize;
                tot_frame_size[0] = dsize;
                total_datasize = dsize;
        }

        new_frame_size = total_datasize + num_frames * VP9_HEADER_SIZE;

        if (new_frame_size >= vb2_plane_size(buf, 0)) {
                dev_warn(core->dev, "%s: unable to update header\n", __func__);
                return 0;
        }

        for (cur_frame = num_frames - 1; cur_frame >= 0; cur_frame--) {
                int framesize = frame_size[cur_frame];
                int framesize_header = framesize + 4;
                int oldframeoff = tot_frame_size[cur_frame] - framesize;
                int outheaderoff =  oldframeoff + cur_frame * VP9_HEADER_SIZE;
                u8 *fdata = dp + outheaderoff;
                u8 *old_framedata = dp + oldframeoff;

                memmove(fdata + VP9_HEADER_SIZE, old_framedata, framesize);

                fdata[0] = (framesize_header >> 24) & 0xff;
                fdata[1] = (framesize_header >> 16) & 0xff;
                fdata[2] = (framesize_header >> 8) & 0xff;
                fdata[3] = (framesize_header >> 0) & 0xff;
                fdata[4] = ((framesize_header >> 24) & 0xff) ^ 0xff;
                fdata[5] = ((framesize_header >> 16) & 0xff) ^ 0xff;
                fdata[6] = ((framesize_header >> 8) & 0xff) ^ 0xff;
                fdata[7] = ((framesize_header >> 0) & 0xff) ^ 0xff;
                fdata[8] = 0;
                fdata[9] = 0;
                fdata[10] = 0;
                fdata[11] = 1;
                fdata[12] = 'A';
                fdata[13] = 'M';
                fdata[14] = 'L';
                fdata[15] = 'V';

                if (!old_header) {
                        /* nothing */
                } else if (old_header > fdata + 16 + framesize) {
                        dev_dbg(core->dev, "%s: data has gaps, setting to 0\n",
                                __func__);
                        memset(fdata + 16 + framesize, 0,
                               (old_header - fdata + 16 + framesize));
                } else if (old_header < fdata + 16 + framesize) {
                        dev_err(core->dev, "%s: data overwritten\n", __func__);
                }
                old_header = fdata;
        }

        return new_frame_size;
}

/* Pad the packet to at least 4KiB bytes otherwise the VDEC unit won't trigger
 * ISRs.
 * Also append a start code 000001ff at the end to trigger
 * the ESPARSER interrupt.
 */
static u32 esparser_pad_start_code(struct amvdec_core *core,
                                   struct vb2_buffer *vb,
                                   u32 payload_size)
{
        u32 pad_size = 0;
        u8 *vaddr = vb2_plane_vaddr(vb, 0);

        if (payload_size < ESPARSER_MIN_PACKET_SIZE) {
                pad_size = ESPARSER_MIN_PACKET_SIZE - payload_size;
                memset(vaddr + payload_size, 0, pad_size);
        }

        if ((payload_size + pad_size + SEARCH_PATTERN_LEN) >
                                                vb2_plane_size(vb, 0)) {
                dev_warn(core->dev, "%s: unable to pad start code\n", __func__);
                return pad_size;
        }

        memset(vaddr + payload_size + pad_size, 0, SEARCH_PATTERN_LEN);
        vaddr[payload_size + pad_size]     = 0x00;
        vaddr[payload_size + pad_size + 1] = 0x00;
        vaddr[payload_size + pad_size + 2] = 0x01;
        vaddr[payload_size + pad_size + 3] = 0xff;

        return pad_size;
}

static int
esparser_write_data(struct amvdec_core *core, dma_addr_t addr, u32 size)
{
        amvdec_write_parser(core, PFIFO_RD_PTR, 0);
        amvdec_write_parser(core, PFIFO_WR_PTR, 0);
        amvdec_write_parser(core, PARSER_CONTROL,
                            ES_WRITE |
                            ES_PARSER_START |
                            ES_SEARCH |
                            (size << ES_PACK_SIZE_BIT));

        amvdec_write_parser(core, PARSER_FETCH_ADDR, addr);
        amvdec_write_parser(core, PARSER_FETCH_CMD,
                            (7 << FETCH_ENDIAN_BIT) |
                            (size + SEARCH_PATTERN_LEN));

        search_done = 0;
        return wait_event_interruptible_timeout(wq, search_done, (HZ / 5));
}

static u32 esparser_vififo_get_free_space(struct amvdec_session *sess)
{
        u32 vififo_usage;
        struct amvdec_ops *vdec_ops = sess->fmt_out->vdec_ops;
        struct amvdec_core *core = sess->core;

        vififo_usage  = vdec_ops->vififo_level(sess);
        vififo_usage += amvdec_read_parser(core, PARSER_VIDEO_HOLE);
        vififo_usage += (6 * SZ_1K); // 6 KiB internal fifo

        if (vififo_usage > sess->vififo_size) {
                dev_warn(sess->core->dev,
                         "VIFIFO usage (%u) > VIFIFO size (%u)\n",
                         vififo_usage, sess->vififo_size);
                return 0;
        }

        return sess->vififo_size - vififo_usage;
}

int esparser_queue_eos(struct amvdec_core *core, const u8 *data, u32 len)
{
        struct device *dev = core->dev;
        void *eos_vaddr;
        dma_addr_t eos_paddr;
        int ret;

        eos_vaddr = dma_alloc_coherent(dev, len + SEARCH_PATTERN_LEN,
                                       &eos_paddr, GFP_KERNEL);
        if (!eos_vaddr)
                return -ENOMEM;

        memcpy(eos_vaddr, data, len);
        ret = esparser_write_data(core, eos_paddr, len);
        dma_free_coherent(dev, len + SEARCH_PATTERN_LEN,
                          eos_vaddr, eos_paddr);

        return ret;
}

static u32 esparser_get_offset(struct amvdec_session *sess)
{
        struct amvdec_core *core = sess->core;
        u32 offset = amvdec_read_parser(core, PARSER_VIDEO_WP) -
                     sess->vififo_paddr;

        if (offset < sess->last_offset)
                sess->wrap_count++;

        sess->last_offset = offset;
        offset += (sess->wrap_count * sess->vififo_size);

        return offset;
}

static int
esparser_queue(struct amvdec_session *sess, struct vb2_v4l2_buffer *vbuf)
{
        int ret;
        struct vb2_buffer *vb = &vbuf->vb2_buf;
        struct amvdec_core *core = sess->core;
        struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;
        u32 payload_size = vb2_get_plane_payload(vb, 0);
        dma_addr_t phy = vb2_dma_contig_plane_dma_addr(vb, 0);
        u32 num_dst_bufs = 0;
        u32 offset;
        u32 pad_size;

        /*
         * When max ref frame is held by VP9, this should be -= 3 to prevent a
         * shortage of CAPTURE buffers on the decoder side.
         * For the future, a good enhancement of the way this is handled could
         * be to notify new capture buffers to the decoding modules, so that
         * they could pause when there is no capture buffer available and
         * resume on this notification.
         */
        if (sess->fmt_out->pixfmt == V4L2_PIX_FMT_VP9) {
                if (codec_ops->num_pending_bufs)
                        num_dst_bufs = codec_ops->num_pending_bufs(sess);

                num_dst_bufs += v4l2_m2m_num_dst_bufs_ready(sess->m2m_ctx);
                num_dst_bufs -= 3;

                if (esparser_vififo_get_free_space(sess) < payload_size ||
                    atomic_read(&sess->esparser_queued_bufs) >= num_dst_bufs)
                        return -EAGAIN;
        } else if (esparser_vififo_get_free_space(sess) < payload_size) {
                return -EAGAIN;
        }

        v4l2_m2m_src_buf_remove_by_buf(sess->m2m_ctx, vbuf);

        offset = esparser_get_offset(sess);

        ret = amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags);
        if (ret) {
                v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
                return ret;
        }

        dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X flags = %08X\n",
                vb->timestamp, payload_size, offset, vbuf->flags);

        vbuf->flags = 0;
        vbuf->field = V4L2_FIELD_NONE;
        vbuf->sequence = sess->sequence_out++;

        if (sess->fmt_out->pixfmt == V4L2_PIX_FMT_VP9) {
                payload_size = vp9_update_header(core, vb);

                /* If unable to alter buffer to add headers */
                if (payload_size == 0) {
                        amvdec_remove_ts(sess, vb->timestamp);
                        v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);

                        return 0;
                }
        }

        pad_size = esparser_pad_start_code(core, vb, payload_size);
        ret = esparser_write_data(core, phy, payload_size + pad_size);

        if (ret <= 0) {
                dev_warn(core->dev, "esparser: input parsing error\n");
                amvdec_remove_ts(sess, vb->timestamp);
                v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
                amvdec_write_parser(core, PARSER_FETCH_CMD, 0);

                return 0;
        }

        atomic_inc(&sess->esparser_queued_bufs);
        v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_DONE);

        return 0;
}

void esparser_queue_all_src(struct work_struct *work)
{
        struct v4l2_m2m_buffer *buf, *n;
        struct amvdec_session *sess =
                container_of(work, struct amvdec_session, esparser_queue_work);

        mutex_lock(&sess->lock);
        v4l2_m2m_for_each_src_buf_safe(sess->m2m_ctx, buf, n) {
                if (sess->should_stop)
                        break;

                if (esparser_queue(sess, &buf->vb) < 0)
                        break;
        }
        mutex_unlock(&sess->lock);
}

int esparser_power_up(struct amvdec_session *sess)
{
        struct amvdec_core *core = sess->core;
        struct amvdec_ops *vdec_ops = sess->fmt_out->vdec_ops;

        reset_control_reset(core->esparser_reset);
        amvdec_write_parser(core, PARSER_CONFIG,
                            (10 << PS_CFG_PFIFO_EMPTY_CNT_BIT) |
                            (1  << PS_CFG_MAX_ES_WR_CYCLE_BIT) |
                            (16 << PS_CFG_MAX_FETCH_CYCLE_BIT));

        amvdec_write_parser(core, PFIFO_RD_PTR, 0);
        amvdec_write_parser(core, PFIFO_WR_PTR, 0);

        amvdec_write_parser(core, PARSER_SEARCH_PATTERN,
                            ES_START_CODE_PATTERN);
        amvdec_write_parser(core, PARSER_SEARCH_MASK, ES_START_CODE_MASK);

        amvdec_write_parser(core, PARSER_CONFIG,
                            (10 << PS_CFG_PFIFO_EMPTY_CNT_BIT) |
                            (1  << PS_CFG_MAX_ES_WR_CYCLE_BIT) |
                            (16 << PS_CFG_MAX_FETCH_CYCLE_BIT) |
                            (2  << PS_CFG_STARTCODE_WID_24_BIT));

        amvdec_write_parser(core, PARSER_CONTROL,
                            (ES_SEARCH | ES_PARSER_START));

        amvdec_write_parser(core, PARSER_VIDEO_START_PTR, sess->vififo_paddr);
        amvdec_write_parser(core, PARSER_VIDEO_END_PTR,
                            sess->vififo_paddr + sess->vififo_size - 8);
        amvdec_write_parser(core, PARSER_ES_CONTROL,
                            amvdec_read_parser(core, PARSER_ES_CONTROL) & ~1);

        if (vdec_ops->conf_esparser)
                vdec_ops->conf_esparser(sess);

        amvdec_write_parser(core, PARSER_INT_STATUS, 0xffff);
        amvdec_write_parser(core, PARSER_INT_ENABLE,
                            BIT(PARSER_INT_HOST_EN_BIT));

        return 0;
}

int esparser_init(struct platform_device *pdev, struct amvdec_core *core)
{
        struct device *dev = &pdev->dev;
        int ret;
        int irq;

        irq = platform_get_irq_byname(pdev, "esparser");
        if (irq < 0)
                return irq;

        ret = devm_request_irq(dev, irq, esparser_isr, IRQF_SHARED,
                               "esparserirq", core);
        if (ret) {
                dev_err(dev, "Failed requesting ESPARSER IRQ\n");
                return ret;
        }

        core->esparser_reset =
                devm_reset_control_get_exclusive(dev, "esparser");
        if (IS_ERR(core->esparser_reset)) {
                dev_err(dev, "Failed to get esparser_reset\n");
                return PTR_ERR(core->esparser_reset);
        }

        return 0;
}