fec.c

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/*
 * Bestcomm FEC tasks driver
 *
 *
 * Copyright (C) 2006-2007 Sylvain Munaut <[email protected]>
 * Copyright (C) 2003-2004 MontaVista, Software, Inc.
 *                         ( by Dale Farnsworth <[email protected]> )
 *
 * 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 "fec.h"


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

/* fec tasks images */
extern u32 bcom_fec_rx_task[];
extern u32 bcom_fec_tx_task[];

/* rx task vars that need to be set before enabling the task */
struct bcom_fec_rx_var {
    u32 enable;     /* (u16*) address of task's control register */
    u32 fifo;       /* (u32*) address of fec's fifo */
    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 */
};

/* rx task incs that need to be set before enabling the task */
struct bcom_fec_rx_inc {
    u16 pad0;
    s16 incr_bytes;
    u16 pad1;
    s16 incr_dst;
    u16 pad2;
    s16 incr_dst_ma;
};

/* tx task vars that need to be set before enabling the task */
struct bcom_fec_tx_var {
    u32 DRD;        /* (u32*) address of self-modified DRD */
    u32 fifo;       /* (u32*) address of fec's fifo */
    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;    /* set by uCode for each packet */
};

/* tx task incs that need to be set before enabling the task */
struct bcom_fec_tx_inc {
    u16 pad0;
    s16 incr_bytes;
    u16 pad1;
    s16 incr_src;
    u16 pad2;
    s16 incr_src_ma;
};

/* private structure in the task */
struct bcom_fec_priv {
    phys_addr_t fifo;
    int     maxbufsize;
};


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

struct bcom_task *
bcom_fec_rx_init(int queue_len, phys_addr_t fifo, int maxbufsize)
{
    struct bcom_task *tsk;
    struct bcom_fec_priv *priv;

    tsk = bcom_task_alloc(queue_len, sizeof(struct bcom_fec_bd),
                sizeof(struct bcom_fec_priv));
    if (!tsk)
        return NULL;

    tsk->flags = BCOM_FLAGS_NONE;

    priv = tsk->priv;
    priv->fifo = fifo;
    priv->maxbufsize = maxbufsize;

    if (bcom_fec_rx_reset(tsk)) {
        bcom_task_free(tsk);
        return NULL;
    }

    return tsk;
}
EXPORT_SYMBOL_GPL(bcom_fec_rx_init);

int
bcom_fec_rx_reset(struct bcom_task *tsk)
{
    struct bcom_fec_priv *priv = tsk->priv;
    struct bcom_fec_rx_var *var;
    struct bcom_fec_rx_inc *inc;

    /* Shutdown the task */
    bcom_disable_task(tsk->tasknum);

    /* Reset the microcode */
    var = (struct bcom_fec_rx_var *) bcom_task_var(tsk->tasknum);
    inc = (struct bcom_fec_rx_inc *) bcom_task_inc(tsk->tasknum);

    if (bcom_load_image(tsk->tasknum, bcom_fec_rx_task))
        return -1;

    var->enable = bcom_eng->regs_base +
                offsetof(struct mpc52xx_sdma, tcr[tsk->tasknum]);
    var->fifo   = (u32) priv->fifo;
    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 = priv->maxbufsize;

    inc->incr_bytes = -(s16)sizeof(u32);    /* These should be in the   */
    inc->incr_dst   = sizeof(u32);      /* task image, but we stick */
    inc->incr_dst_ma= sizeof(u8);       /* to the official ones     */

    /* Reset the BDs */
    tsk->index = 0;
    tsk->outdex = 0;

    memset(tsk->bd, 0x00, tsk->num_bd * tsk->bd_size);

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

    out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_FEC_RX], BCOM_IPR_FEC_RX);

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

    return 0;
}
EXPORT_SYMBOL_GPL(bcom_fec_rx_reset);

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



    /* Return 2nd to last DRD */
    /* This is an ugly hack, but at least it's only done
       once at initialization */
static u32 *self_modified_drd(int tasknum)
{
    u32 *desc;
    int num_descs;
    int drd_count;
    int i;

    num_descs = bcom_task_num_descs(tasknum);
    desc = bcom_task_desc(tasknum) + num_descs - 1;
    drd_count = 0;
    for (i=0; i<num_descs; i++, desc--)
        if (bcom_desc_is_drd(*desc) && ++drd_count == 3)
            break;
    return desc;
}

struct bcom_task *
bcom_fec_tx_init(int queue_len, phys_addr_t fifo)
{
    struct bcom_task *tsk;
    struct bcom_fec_priv *priv;

    tsk = bcom_task_alloc(queue_len, sizeof(struct bcom_fec_bd),
                sizeof(struct bcom_fec_priv));
    if (!tsk)
        return NULL;

    tsk->flags = BCOM_FLAGS_ENABLE_TASK;

    priv = tsk->priv;
    priv->fifo = fifo;

    if (bcom_fec_tx_reset(tsk)) {
        bcom_task_free(tsk);
        return NULL;
    }

    return tsk;
}
EXPORT_SYMBOL_GPL(bcom_fec_tx_init);

int
bcom_fec_tx_reset(struct bcom_task *tsk)
{
    struct bcom_fec_priv *priv = tsk->priv;
    struct bcom_fec_tx_var *var;
    struct bcom_fec_tx_inc *inc;

    /* Shutdown the task */
    bcom_disable_task(tsk->tasknum);

    /* Reset the microcode */
    var = (struct bcom_fec_tx_var *) bcom_task_var(tsk->tasknum);
    inc = (struct bcom_fec_tx_inc *) bcom_task_inc(tsk->tasknum);

    if (bcom_load_image(tsk->tasknum, bcom_fec_tx_task))
        return -1;

    var->enable = bcom_eng->regs_base +
                offsetof(struct mpc52xx_sdma, tcr[tsk->tasknum]);
    var->fifo   = (u32) priv->fifo;
    var->DRD    = bcom_sram_va2pa(self_modified_drd(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;

    inc->incr_bytes = -(s16)sizeof(u32);    /* These should be in the   */
    inc->incr_src   = sizeof(u32);      /* task image, but we stick */
    inc->incr_src_ma= sizeof(u8);       /* to the official ones     */

    /* Reset the BDs */
    tsk->index = 0;
    tsk->outdex = 0;

    memset(tsk->bd, 0x00, tsk->num_bd * tsk->bd_size);

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

    out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_FEC_TX], BCOM_IPR_FEC_TX);

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

    return 0;
}
EXPORT_SYMBOL_GPL(bcom_fec_tx_reset);

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


MODULE_DESCRIPTION("BestComm FEC tasks driver");
MODULE_AUTHOR("Dale Farnsworth <[email protected]>");
MODULE_LICENSE("GPL v2");