/**
 * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
 *
 * This source file is released under GPL v2 license (no other versions).
 * See the COPYING file included in the main directory of this source
 * distribution for the license terms and conditions.
 *
 * @File        ctresource.c
 *
 * @Brief
 * This file contains the implementation of some generic helper functions.
 *
 * @Author      Liu Chun
 * @Date        May 15 2008
 *
 */

#include "ctresource.h"
#include "cthardware.h"
#include <linux/err.h>
#include <linux/slab.h>

#define AUDIO_SLOT_BLOCK_NUM    256

/* Resource allocation based on bit-map management mechanism */
static int
get_resource(u8 *rscs, unsigned int amount,
             unsigned int multi, unsigned int *ridx)
{
        int i, j, k, n;

        /* Check whether there are sufficient resources to meet request. */
        for (i = 0, n = multi; i < amount; i++) {
                j = i / 8;
                k = i % 8;
                if (rscs[j] & ((u8)1 << k)) {
                        n = multi;
                        continue;
                }
                if (!(--n))
                        break; /* found sufficient contiguous resources */
        }

        if (i >= amount) {
                /* Can not find sufficient contiguous resources */
                return -ENOENT;
        }

        /* Mark the contiguous bits in resource bit-map as used */
        for (n = multi; n > 0; n--) {
                j = i / 8;
                k = i % 8;
                rscs[j] |= ((u8)1 << k);
                i--;
        }

        *ridx = i + 1;

        return 0;
}

static int put_resource(u8 *rscs, unsigned int multi, unsigned int idx)
{
        unsigned int i, j, k, n;

        /* Mark the contiguous bits in resource bit-map as used */
        for (n = multi, i = idx; n > 0; n--) {
                j = i / 8;
                k = i % 8;
                rscs[j] &= ~((u8)1 << k);
                i++;
        }

        return 0;
}

int mgr_get_resource(struct rsc_mgr *mgr, unsigned int n, unsigned int *ridx)
{
        int err;

        if (n > mgr->avail)
                return -ENOENT;

        err = get_resource(mgr->rscs, mgr->amount, n, ridx);
        if (!err)
                mgr->avail -= n;

        return err;
}

int mgr_put_resource(struct rsc_mgr *mgr, unsigned int n, unsigned int idx)
{
        put_resource(mgr->rscs, n, idx);
        mgr->avail += n;

        return 0;
}

static unsigned char offset_in_audio_slot_block[NUM_RSCTYP] = {
        /* SRC channel is at Audio Ring slot 1 every 16 slots. */
        [SRC]           = 0x1,
        [AMIXER]        = 0x4,
        [SUM]           = 0xc,
};

static int rsc_index(const struct rsc *rsc)
{
    return rsc->conj;
}

static int audio_ring_slot(const struct rsc *rsc)
{
    return (rsc->conj << 4) + offset_in_audio_slot_block[rsc->type];
}

static int rsc_next_conj(struct rsc *rsc)
{
        unsigned int i;
        for (i = 0; (i < 8) && (!(rsc->msr & (0x1 << i))); )
                i++;
        rsc->conj += (AUDIO_SLOT_BLOCK_NUM >> i);
        return rsc->conj;
}

static int rsc_master(struct rsc *rsc)
{
        return rsc->conj = rsc->idx;
}

static struct rsc_ops rsc_generic_ops = {
        .index          = rsc_index,
        .output_slot    = audio_ring_slot,
        .master         = rsc_master,
        .next_conj      = rsc_next_conj,
};

int rsc_init(struct rsc *rsc, u32 idx, enum RSCTYP type, u32 msr, void *hw)
{
        int err = 0;

        rsc->idx = idx;
        rsc->conj = idx;
        rsc->type = type;
        rsc->msr = msr;
        rsc->hw = hw;
        rsc->ops = &rsc_generic_ops;
        if (!hw) {
                rsc->ctrl_blk = NULL;
                return 0;
        }

        switch (type) {
        case SRC:
                err = ((struct hw *)hw)->src_rsc_get_ctrl_blk(&rsc->ctrl_blk);
                break;
        case AMIXER:
                err = ((struct hw *)hw)->
                                amixer_rsc_get_ctrl_blk(&rsc->ctrl_blk);
                break;
        case SRCIMP:
        case SUM:
        case DAIO:
                break;
        default:
                printk(KERN_ERR
                       "ctxfi: Invalid resource type value %d!\n", type);
                return -EINVAL;
        }

        if (err) {
                printk(KERN_ERR
                       "ctxfi: Failed to get resource control block!\n");
                return err;
        }

        return 0;
}

int rsc_uninit(struct rsc *rsc)
{
        if ((NULL != rsc->hw) && (NULL != rsc->ctrl_blk)) {
                switch (rsc->type) {
                case SRC:
                        ((struct hw *)rsc->hw)->
                                src_rsc_put_ctrl_blk(rsc->ctrl_blk);
                        break;
                case AMIXER:
                        ((struct hw *)rsc->hw)->
                                amixer_rsc_put_ctrl_blk(rsc->ctrl_blk);
                        break;
                case SUM:
                case DAIO:
                        break;
                default:
                        printk(KERN_ERR "ctxfi: "
                               "Invalid resource type value %d!\n", rsc->type);
                        break;
                }

                rsc->hw = rsc->ctrl_blk = NULL;
        }

        rsc->idx = rsc->conj = 0;
        rsc->type = NUM_RSCTYP;
        rsc->msr = 0;

        return 0;
}

int rsc_mgr_init(struct rsc_mgr *mgr, enum RSCTYP type,
                 unsigned int amount, void *hw_obj)
{
        int err = 0;
        struct hw *hw = hw_obj;

        mgr->type = NUM_RSCTYP;

        mgr->rscs = kzalloc(((amount + 8 - 1) / 8), GFP_KERNEL);
        if (!mgr->rscs)
                return -ENOMEM;

        switch (type) {
        case SRC:
                err = hw->src_mgr_get_ctrl_blk(&mgr->ctrl_blk);
                break;
        case SRCIMP:
                err = hw->srcimp_mgr_get_ctrl_blk(&mgr->ctrl_blk);
                break;
        case AMIXER:
                err = hw->amixer_mgr_get_ctrl_blk(&mgr->ctrl_blk);
                break;
        case DAIO:
                err = hw->daio_mgr_get_ctrl_blk(hw, &mgr->ctrl_blk);
                break;
        case SUM:
                break;
        default:
                printk(KERN_ERR
                       "ctxfi: Invalid resource type value %d!\n", type);
                err = -EINVAL;
                goto error;
        }

        if (err) {
                printk(KERN_ERR
                       "ctxfi: Failed to get manager control block!\n");
                goto error;
        }

        mgr->type = type;
        mgr->avail = mgr->amount = amount;
        mgr->hw = hw;

        return 0;

error:
        kfree(mgr->rscs);
        return err;
}

int rsc_mgr_uninit(struct rsc_mgr *mgr)
{
        if (NULL != mgr->rscs) {
                kfree(mgr->rscs);
                mgr->rscs = NULL;
        }

        if ((NULL != mgr->hw) && (NULL != mgr->ctrl_blk)) {
                switch (mgr->type) {
                case SRC:
                        ((struct hw *)mgr->hw)->
                                src_mgr_put_ctrl_blk(mgr->ctrl_blk);
                        break;
                case SRCIMP:
                        ((struct hw *)mgr->hw)->
                                srcimp_mgr_put_ctrl_blk(mgr->ctrl_blk);
                        break;
                case AMIXER:
                        ((struct hw *)mgr->hw)->
                                amixer_mgr_put_ctrl_blk(mgr->ctrl_blk);
                        break;
                case DAIO:
                        ((struct hw *)mgr->hw)->
                                daio_mgr_put_ctrl_blk(mgr->ctrl_blk);
                        break;
                case SUM:
                        break;
                default:
                        printk(KERN_ERR "ctxfi: "
                               "Invalid resource type value %d!\n", mgr->type);
                        break;
                }

                mgr->hw = mgr->ctrl_blk = NULL;
        }

        mgr->type = NUM_RSCTYP;
        mgr->avail = mgr->amount = 0;

        return 0;
}