ocpi.c

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/*
 * linux/arch/arm/plat-omap/ocpi.c
 *
 * Minimal OCP bus support for omap16xx
 *
 * Copyright (C) 2003 - 2005 Nokia Corporation
 * Copyright (C) 2012 Texas Instruments, Inc.
 * Written by Tony Lindgren <[email protected]>
 *
 * Modified for clock framework by Paul Mundt <[email protected]>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <mach/hardware.h>

#include "common.h"

#define OCPI_BASE       0xfffec320
#define OCPI_FAULT      (OCPI_BASE + 0x00)
#define OCPI_CMD_FAULT      (OCPI_BASE + 0x04)
#define OCPI_SINT0      (OCPI_BASE + 0x08)
#define OCPI_TABORT     (OCPI_BASE + 0x0c)
#define OCPI_SINT1      (OCPI_BASE + 0x10)
#define OCPI_PROT       (OCPI_BASE + 0x14)
#define OCPI_SEC        (OCPI_BASE + 0x18)

/* USB OHCI OCPI access error registers */
#define HOSTUEADDR  0xfffba0e0
#define HOSTUESTATUS    0xfffba0e4

static struct clk *ocpi_ck;

/*
 * Enables device access to OMAP buses via the OCPI bridge
 * FIXME: Add locking
 */
int ocpi_enable(void)
{
    unsigned int val;

    if (!cpu_is_omap16xx())
        return -ENODEV;

    /* Enable access for OHCI in OCPI */
    val = omap_readl(OCPI_PROT);
    val &= ~0xff;
    /* val &= (1 << 0);  Allow access only to EMIFS */
    omap_writel(val, OCPI_PROT);

    val = omap_readl(OCPI_SEC);
    val &= ~0xff;
    omap_writel(val, OCPI_SEC);

    return 0;
}
EXPORT_SYMBOL(ocpi_enable);

static int __init omap_ocpi_init(void)
{
    if (!cpu_is_omap16xx())
        return -ENODEV;

    ocpi_ck = clk_get(NULL, "l3_ocpi_ck");
    if (IS_ERR(ocpi_ck))
        return PTR_ERR(ocpi_ck);

    clk_enable(ocpi_ck);
    ocpi_enable();
    pr_info("OMAP OCPI interconnect driver loaded\n");

    return 0;
}

static void __exit omap_ocpi_exit(void)
{
    /* REVISIT: Disable OCPI */

    if (!cpu_is_omap16xx())
        return;

    clk_disable(ocpi_ck);
    clk_put(ocpi_ck);
}

MODULE_AUTHOR("Tony Lindgren <[email protected]>");
MODULE_DESCRIPTION("OMAP OCPI bus controller module");
MODULE_LICENSE("GPL");
module_init(omap_ocpi_init);
module_exit(omap_ocpi_exit);