ata.c

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/*
 * Bestcomm ATA task driver
 *
 *
 * Patterned after bestcomm/fec.c by Dale Farnsworth <[email protected]>
 *                                   2003-2004 (c) MontaVista, Software, Inc.
 *
 * Copyright (C) 2006-2007 Sylvain Munaut <[email protected]>
 * Copyright (C) 2006      Freescale - John Rigby
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <asm/io.h>

#include "bestcomm.h"
#include "bestcomm_priv.h"
#include "ata.h"


/* ======================================================================== */
/* Task image/var/inc                                                       */
/* ======================================================================== */

/* ata task image */
extern u32 bcom_ata_task[];

/* ata task vars that need to be set before enabling the task */
struct bcom_ata_var {
    u32 enable;     /* (u16*) address of task's control register */
    u32 bd_base;        /* (struct bcom_bd*) beginning of ring buffer */
    u32 bd_last;        /* (struct bcom_bd*) end of ring buffer */
    u32 bd_start;       /* (struct bcom_bd*) current bd */
    u32 buffer_size;    /* size of receive buffer */
};

/* ata task incs that need to be set before enabling the task */
struct bcom_ata_inc {
    u16 pad0;
    s16 incr_bytes;
    u16 pad1;
    s16 incr_dst;
    u16 pad2;
    s16 incr_src;
};


/* ======================================================================== */
/* Task support code                                                        */
/* ======================================================================== */

struct bcom_task *
bcom_ata_init(int queue_len, int maxbufsize)
{
    struct bcom_task *tsk;
    struct bcom_ata_var *var;
    struct bcom_ata_inc *inc;

    /* Prefetch breaks ATA DMA.  Turn it off for ATA DMA */
    bcom_disable_prefetch();

    tsk = bcom_task_alloc(queue_len, sizeof(struct bcom_ata_bd), 0);
    if (!tsk)
        return NULL;

    tsk->flags = BCOM_FLAGS_NONE;

    bcom_ata_reset_bd(tsk);

    var = (struct bcom_ata_var *) bcom_task_var(tsk->tasknum);
    inc = (struct bcom_ata_inc *) bcom_task_inc(tsk->tasknum);

    if (bcom_load_image(tsk->tasknum, bcom_ata_task)) {
        bcom_task_free(tsk);
        return NULL;
    }

    var->enable = bcom_eng->regs_base +
                offsetof(struct mpc52xx_sdma, tcr[tsk->tasknum]);
    var->bd_base    = tsk->bd_pa;
    var->bd_last    = tsk->bd_pa + ((tsk->num_bd-1) * tsk->bd_size);
    var->bd_start   = tsk->bd_pa;
    var->buffer_size = maxbufsize;

    /* Configure some stuff */
    bcom_set_task_pragma(tsk->tasknum, BCOM_ATA_PRAGMA);
    bcom_set_task_auto_start(tsk->tasknum, tsk->tasknum);

    out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ATA_RX], BCOM_IPR_ATA_RX);
    out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ATA_TX], BCOM_IPR_ATA_TX);

    out_be32(&bcom_eng->regs->IntPend, 1<<tsk->tasknum); /* Clear ints */

    return tsk;
}
EXPORT_SYMBOL_GPL(bcom_ata_init);

void bcom_ata_rx_prepare(struct bcom_task *tsk)
{
    struct bcom_ata_inc *inc;

    inc = (struct bcom_ata_inc *) bcom_task_inc(tsk->tasknum);

    inc->incr_bytes = -(s16)sizeof(u32);
    inc->incr_src   = 0;
    inc->incr_dst   = sizeof(u32);

    bcom_set_initiator(tsk->tasknum, BCOM_INITIATOR_ATA_RX);
}
EXPORT_SYMBOL_GPL(bcom_ata_rx_prepare);

void bcom_ata_tx_prepare(struct bcom_task *tsk)
{
    struct bcom_ata_inc *inc;

    inc = (struct bcom_ata_inc *) bcom_task_inc(tsk->tasknum);

    inc->incr_bytes = -(s16)sizeof(u32);
    inc->incr_src   = sizeof(u32);
    inc->incr_dst   = 0;

    bcom_set_initiator(tsk->tasknum, BCOM_INITIATOR_ATA_TX);
}
EXPORT_SYMBOL_GPL(bcom_ata_tx_prepare);

void bcom_ata_reset_bd(struct bcom_task *tsk)
{
    struct bcom_ata_var *var;

    /* Reset all BD */
    memset(tsk->bd, 0x00, tsk->num_bd * tsk->bd_size);

    tsk->index = 0;
    tsk->outdex = 0;

    var = (struct bcom_ata_var *) bcom_task_var(tsk->tasknum);
    var->bd_start = var->bd_base;
}
EXPORT_SYMBOL_GPL(bcom_ata_reset_bd);

void bcom_ata_release(struct bcom_task *tsk)
{
    /* Nothing special for the ATA tasks */
    bcom_task_free(tsk);
}
EXPORT_SYMBOL_GPL(bcom_ata_release);


MODULE_DESCRIPTION("BestComm ATA task driver");
MODULE_AUTHOR("John Rigby");
MODULE_LICENSE("GPL v2");