bestcomm.c

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/*
 * Driver for MPC52xx processor BestComm peripheral controller
 *
 *
 * Copyright (C) 2006-2007 Sylvain Munaut <[email protected]>
 * Copyright (C) 2005      Varma Electronics Oy,
 *                         ( by Andrey Volkov <[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/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mpc52xx.h>

#include "sram.h"
#include "bestcomm_priv.h"
#include "bestcomm.h"

#define DRIVER_NAME "bestcomm-core"

/* MPC5200 device tree match tables */
static struct of_device_id mpc52xx_sram_ids[] __devinitdata = {
    { .compatible = "fsl,mpc5200-sram", },
    { .compatible = "mpc5200-sram", },
    {}
};


struct bcom_engine *bcom_eng = NULL;
EXPORT_SYMBOL_GPL(bcom_eng);    /* needed for inline functions */

/* ======================================================================== */
/* Public and private API                                                   */
/* ======================================================================== */

/* Private API */

struct bcom_task *
bcom_task_alloc(int bd_count, int bd_size, int priv_size)
{
    int i, tasknum = -1;
    struct bcom_task *tsk;

    /* Don't try to do anything if bestcomm init failed */
    if (!bcom_eng)
        return NULL;

    /* Get and reserve a task num */
    spin_lock(&bcom_eng->lock);

    for (i=0; i<BCOM_MAX_TASKS; i++)
        if (!bcom_eng->tdt[i].stop) {   /* we use stop as a marker */
            bcom_eng->tdt[i].stop = 0xfffffffful; /* dummy addr */
            tasknum = i;
            break;
        }

    spin_unlock(&bcom_eng->lock);

    if (tasknum < 0)
        return NULL;

    /* Allocate our structure */
    tsk = kzalloc(sizeof(struct bcom_task) + priv_size, GFP_KERNEL);
    if (!tsk)
        goto error;

    tsk->tasknum = tasknum;
    if (priv_size)
        tsk->priv = (void*)tsk + sizeof(struct bcom_task);

    /* Get IRQ of that task */
    tsk->irq = irq_of_parse_and_map(bcom_eng->ofnode, tsk->tasknum);
    if (tsk->irq == NO_IRQ)
        goto error;

    /* Init the BDs, if needed */
    if (bd_count) {
        tsk->cookie = kmalloc(sizeof(void*) * bd_count, GFP_KERNEL);
        if (!tsk->cookie)
            goto error;

        tsk->bd = bcom_sram_alloc(bd_count * bd_size, 4, &tsk->bd_pa);
        if (!tsk->bd)
            goto error;
        memset(tsk->bd, 0x00, bd_count * bd_size);

        tsk->num_bd = bd_count;
        tsk->bd_size = bd_size;
    }

    return tsk;

error:
    if (tsk) {
        if (tsk->irq != NO_IRQ)
            irq_dispose_mapping(tsk->irq);
        bcom_sram_free(tsk->bd);
        kfree(tsk->cookie);
        kfree(tsk);
    }

    bcom_eng->tdt[tasknum].stop = 0;

    return NULL;
}
EXPORT_SYMBOL_GPL(bcom_task_alloc);

void
bcom_task_free(struct bcom_task *tsk)
{
    /* Stop the task */
    bcom_disable_task(tsk->tasknum);

    /* Clear TDT */
    bcom_eng->tdt[tsk->tasknum].start = 0;
    bcom_eng->tdt[tsk->tasknum].stop  = 0;

    /* Free everything */
    irq_dispose_mapping(tsk->irq);
    bcom_sram_free(tsk->bd);
    kfree(tsk->cookie);
    kfree(tsk);
}
EXPORT_SYMBOL_GPL(bcom_task_free);

int
bcom_load_image(int task, u32 *task_image)
{
    struct bcom_task_header *hdr = (struct bcom_task_header *)task_image;
    struct bcom_tdt *tdt;
    u32 *desc, *var, *inc;
    u32 *desc_src, *var_src, *inc_src;

    /* Safety checks */
    if (hdr->magic != BCOM_TASK_MAGIC) {
        printk(KERN_ERR DRIVER_NAME
            ": Trying to load invalid microcode\n");
        return -EINVAL;
    }

    if ((task < 0) || (task >= BCOM_MAX_TASKS)) {
        printk(KERN_ERR DRIVER_NAME
            ": Trying to load invalid task %d\n", task);
        return -EINVAL;
    }

    /* Initial load or reload */
    tdt = &bcom_eng->tdt[task];

    if (tdt->start) {
        desc = bcom_task_desc(task);
        if (hdr->desc_size != bcom_task_num_descs(task)) {
            printk(KERN_ERR DRIVER_NAME
                ": Trying to reload wrong task image "
                "(%d size %d/%d)!\n",
                task,
                hdr->desc_size,
                bcom_task_num_descs(task));
            return -EINVAL;
        }
    } else {
        phys_addr_t start_pa;

        desc = bcom_sram_alloc(hdr->desc_size * sizeof(u32), 4, &start_pa);
        if (!desc)
            return -ENOMEM;

        tdt->start = start_pa;
        tdt->stop = start_pa + ((hdr->desc_size-1) * sizeof(u32));
    }

    var = bcom_task_var(task);
    inc = bcom_task_inc(task);

    /* Clear & copy */
    memset(var, 0x00, BCOM_VAR_SIZE);
    memset(inc, 0x00, BCOM_INC_SIZE);

    desc_src = (u32 *)(hdr + 1);
    var_src = desc_src + hdr->desc_size;
    inc_src = var_src + hdr->var_size;

    memcpy(desc, desc_src, hdr->desc_size * sizeof(u32));
    memcpy(var + hdr->first_var, var_src, hdr->var_size * sizeof(u32));
    memcpy(inc, inc_src, hdr->inc_size * sizeof(u32));

    return 0;
}
EXPORT_SYMBOL_GPL(bcom_load_image);

void
bcom_set_initiator(int task, int initiator)
{
    int i;
    int num_descs;
    u32 *desc;
    int next_drd_has_initiator;

    bcom_set_tcr_initiator(task, initiator);

    /* Just setting tcr is apparently not enough due to some problem */
    /* with it. So we just go thru all the microcode and replace in  */
    /* the DRD directly */

    desc = bcom_task_desc(task);
    next_drd_has_initiator = 1;
    num_descs = bcom_task_num_descs(task);

    for (i=0; i<num_descs; i++, desc++) {
        if (!bcom_desc_is_drd(*desc))
            continue;
        if (next_drd_has_initiator)
            if (bcom_desc_initiator(*desc) != BCOM_INITIATOR_ALWAYS)
                bcom_set_desc_initiator(desc, initiator);
        next_drd_has_initiator = !bcom_drd_is_extended(*desc);
    }
}
EXPORT_SYMBOL_GPL(bcom_set_initiator);


/* Public API */

void
bcom_enable(struct bcom_task *tsk)
{
    bcom_enable_task(tsk->tasknum);
}
EXPORT_SYMBOL_GPL(bcom_enable);

void
bcom_disable(struct bcom_task *tsk)
{
    bcom_disable_task(tsk->tasknum);
}
EXPORT_SYMBOL_GPL(bcom_disable);


/* ======================================================================== */
/* Engine init/cleanup                                                      */
/* ======================================================================== */

/* Function Descriptor table */
/* this will need to be updated if Freescale changes their task code FDT */
static u32 fdt_ops[] = {
    0xa0045670, /* FDT[48] - load_acc()   */
    0x80045670, /* FDT[49] - unload_acc() */
    0x21800000, /* FDT[50] - and()        */
    0x21e00000, /* FDT[51] - or()         */
    0x21500000, /* FDT[52] - xor()        */
    0x21400000, /* FDT[53] - andn()       */
    0x21500000, /* FDT[54] - not()        */
    0x20400000, /* FDT[55] - add()        */
    0x20500000, /* FDT[56] - sub()        */
    0x20800000, /* FDT[57] - lsh()        */
    0x20a00000, /* FDT[58] - rsh()        */
    0xc0170000, /* FDT[59] - crc8()       */
    0xc0145670, /* FDT[60] - crc16()      */
    0xc0345670, /* FDT[61] - crc32()      */
    0xa0076540, /* FDT[62] - endian32()   */
    0xa0000760, /* FDT[63] - endian16()   */
};


static int __devinit
bcom_engine_init(void)
{
    int task;
    phys_addr_t tdt_pa, ctx_pa, var_pa, fdt_pa;
    unsigned int tdt_size, ctx_size, var_size, fdt_size;

    /* Allocate & clear SRAM zones for FDT, TDTs, contexts and vars/incs */
    tdt_size = BCOM_MAX_TASKS * sizeof(struct bcom_tdt);
    ctx_size = BCOM_MAX_TASKS * BCOM_CTX_SIZE;
    var_size = BCOM_MAX_TASKS * (BCOM_VAR_SIZE + BCOM_INC_SIZE);
    fdt_size = BCOM_FDT_SIZE;

    bcom_eng->tdt = bcom_sram_alloc(tdt_size, sizeof(u32), &tdt_pa);
    bcom_eng->ctx = bcom_sram_alloc(ctx_size, BCOM_CTX_ALIGN, &ctx_pa);
    bcom_eng->var = bcom_sram_alloc(var_size, BCOM_VAR_ALIGN, &var_pa);
    bcom_eng->fdt = bcom_sram_alloc(fdt_size, BCOM_FDT_ALIGN, &fdt_pa);

    if (!bcom_eng->tdt || !bcom_eng->ctx || !bcom_eng->var || !bcom_eng->fdt) {
        printk(KERN_ERR "DMA: SRAM alloc failed in engine init !\n");

        bcom_sram_free(bcom_eng->tdt);
        bcom_sram_free(bcom_eng->ctx);
        bcom_sram_free(bcom_eng->var);
        bcom_sram_free(bcom_eng->fdt);

        return -ENOMEM;
    }

    memset(bcom_eng->tdt, 0x00, tdt_size);
    memset(bcom_eng->ctx, 0x00, ctx_size);
    memset(bcom_eng->var, 0x00, var_size);
    memset(bcom_eng->fdt, 0x00, fdt_size);

    /* Copy the FDT for the EU#3 */
    memcpy(&bcom_eng->fdt[48], fdt_ops, sizeof(fdt_ops));

    /* Initialize Task base structure */
    for (task=0; task<BCOM_MAX_TASKS; task++)
    {
        out_be16(&bcom_eng->regs->tcr[task], 0);
        out_8(&bcom_eng->regs->ipr[task], 0);

        bcom_eng->tdt[task].context = ctx_pa;
        bcom_eng->tdt[task].var = var_pa;
        bcom_eng->tdt[task].fdt = fdt_pa;

        var_pa += BCOM_VAR_SIZE + BCOM_INC_SIZE;
        ctx_pa += BCOM_CTX_SIZE;
    }

    out_be32(&bcom_eng->regs->taskBar, tdt_pa);

    /* Init 'always' initiator */
    out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ALWAYS], BCOM_IPR_ALWAYS);

    /* Disable COMM Bus Prefetch on the original 5200; it's broken */
    if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
        bcom_disable_prefetch();

    /* Init lock */
    spin_lock_init(&bcom_eng->lock);

    return 0;
}

static void
bcom_engine_cleanup(void)
{
    int task;

    /* Stop all tasks */
    for (task=0; task<BCOM_MAX_TASKS; task++)
    {
        out_be16(&bcom_eng->regs->tcr[task], 0);
        out_8(&bcom_eng->regs->ipr[task], 0);
    }

    out_be32(&bcom_eng->regs->taskBar, 0ul);

    /* Release the SRAM zones */
    bcom_sram_free(bcom_eng->tdt);
    bcom_sram_free(bcom_eng->ctx);
    bcom_sram_free(bcom_eng->var);
    bcom_sram_free(bcom_eng->fdt);
}


/* ======================================================================== */
/* OF platform driver                                                       */
/* ======================================================================== */

static int __devinit mpc52xx_bcom_probe(struct platform_device *op)
{
    struct device_node *ofn_sram;
    struct resource res_bcom;

    int rv;

    /* Inform user we're ok so far */
    printk(KERN_INFO "DMA: MPC52xx BestComm driver\n");

    /* Get the bestcomm node */
    of_node_get(op->dev.of_node);

    /* Prepare SRAM */
    ofn_sram = of_find_matching_node(NULL, mpc52xx_sram_ids);
    if (!ofn_sram) {
        printk(KERN_ERR DRIVER_NAME ": "
            "No SRAM found in device tree\n");
        rv = -ENODEV;
        goto error_ofput;
    }
    rv = bcom_sram_init(ofn_sram, DRIVER_NAME);
    of_node_put(ofn_sram);

    if (rv) {
        printk(KERN_ERR DRIVER_NAME ": "
            "Error in SRAM init\n");
        goto error_ofput;
    }

    /* Get a clean struct */
    bcom_eng = kzalloc(sizeof(struct bcom_engine), GFP_KERNEL);
    if (!bcom_eng) {
        printk(KERN_ERR DRIVER_NAME ": "
            "Can't allocate state structure\n");
        rv = -ENOMEM;
        goto error_sramclean;
    }

    /* Save the node */
    bcom_eng->ofnode = op->dev.of_node;

    /* Get, reserve & map io */
    if (of_address_to_resource(op->dev.of_node, 0, &res_bcom)) {
        printk(KERN_ERR DRIVER_NAME ": "
            "Can't get resource\n");
        rv = -EINVAL;
        goto error_sramclean;
    }

    if (!request_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma),
                DRIVER_NAME)) {
        printk(KERN_ERR DRIVER_NAME ": "
            "Can't request registers region\n");
        rv = -EBUSY;
        goto error_sramclean;
    }

    bcom_eng->regs_base = res_bcom.start;
    bcom_eng->regs = ioremap(res_bcom.start, sizeof(struct mpc52xx_sdma));
    if (!bcom_eng->regs) {
        printk(KERN_ERR DRIVER_NAME ": "
            "Can't map registers\n");
        rv = -ENOMEM;
        goto error_release;
    }

    /* Now, do the real init */
    rv = bcom_engine_init();
    if (rv)
        goto error_unmap;

    /* Done ! */
    printk(KERN_INFO "DMA: MPC52xx BestComm engine @%08lx ok !\n",
        (long)bcom_eng->regs_base);

    return 0;

    /* Error path */
error_unmap:
    iounmap(bcom_eng->regs);
error_release:
    release_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma));
error_sramclean:
    kfree(bcom_eng);
    bcom_sram_cleanup();
error_ofput:
    of_node_put(op->dev.of_node);

    printk(KERN_ERR "DMA: MPC52xx BestComm init failed !\n");

    return rv;
}


static int mpc52xx_bcom_remove(struct platform_device *op)
{
    /* Clean up the engine */
    bcom_engine_cleanup();

    /* Cleanup SRAM */
    bcom_sram_cleanup();

    /* Release regs */
    iounmap(bcom_eng->regs);
    release_mem_region(bcom_eng->regs_base, sizeof(struct mpc52xx_sdma));

    /* Release the node */
    of_node_put(bcom_eng->ofnode);

    /* Release memory */
    kfree(bcom_eng);
    bcom_eng = NULL;

    return 0;
}

static struct of_device_id mpc52xx_bcom_of_match[] = {
    { .compatible = "fsl,mpc5200-bestcomm", },
    { .compatible = "mpc5200-bestcomm", },
    {},
};

MODULE_DEVICE_TABLE(of, mpc52xx_bcom_of_match);


static struct platform_driver mpc52xx_bcom_of_platform_driver = {
    .probe      = mpc52xx_bcom_probe,
    .remove     = mpc52xx_bcom_remove,
    .driver = {
        .name = DRIVER_NAME,
        .owner = THIS_MODULE,
        .of_match_table = mpc52xx_bcom_of_match,
    },
};


/* ======================================================================== */
/* Module                                                                   */
/* ======================================================================== */

static int __init
mpc52xx_bcom_init(void)
{
    return platform_driver_register(&mpc52xx_bcom_of_platform_driver);
}

static void __exit
mpc52xx_bcom_exit(void)
{
    platform_driver_unregister(&mpc52xx_bcom_of_platform_driver);
}

/* If we're not a module, we must make sure everything is setup before  */
/* anyone tries to use us ... that's why we use subsys_initcall instead */
/* of module_init. */
subsys_initcall(mpc52xx_bcom_init);
module_exit(mpc52xx_bcom_exit);

MODULE_DESCRIPTION("Freescale MPC52xx BestComm DMA");
MODULE_AUTHOR("Sylvain Munaut <[email protected]>");
MODULE_AUTHOR("Andrey Volkov <[email protected]>");
MODULE_AUTHOR("Dale Farnsworth <[email protected]>");
MODULE_LICENSE("GPL v2");