io.c

Go to the documentation of this file.

/*
 * Based on arch/arm/kernel/io.c
 *
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/export.h>
#include <linux/types.h>
#include <linux/io.h>

/*
 * Copy data from IO memory space to "real" memory space.
 */
void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
{
    unsigned char *t = to;
    while (count) {
        count--;
        *t = readb(from);
        t++;
        from++;
    }
}
EXPORT_SYMBOL(__memcpy_fromio);

/*
 * Copy data from "real" memory space to IO memory space.
 */
void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
{
    const unsigned char *f = from;
    while (count) {
        count--;
        writeb(*f, to);
        f++;
        to++;
    }
}
EXPORT_SYMBOL(__memcpy_toio);

/*
 * "memset" on IO memory space.
 */
void __memset_io(volatile void __iomem *dst, int c, size_t count)
{
    while (count) {
        count--;
        writeb(c, dst);
        dst++;
    }
}
EXPORT_SYMBOL(__memset_io);