mv64x60_udbg.c

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/*
 * udbg serial input/output routines for the Marvell MV64x60 (Discovery).
 *
 * Author: Dale Farnsworth <[email protected]>
 *
 * 2007 (c) MontaVista Software, Inc.  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 <asm/io.h>
#include <asm/prom.h>
#include <asm/udbg.h>

#include <sysdev/mv64x60.h>

#define MPSC_0_CR1_OFFSET   0x000c

#define MPSC_0_CR2_OFFSET   0x0010
#define MPSC_CHR_2_TCS      (1 << 9)

#define MPSC_0_CHR_10_OFFSET    0x0030

#define MPSC_INTR_CAUSE_OFF_0   0x0004
#define MPSC_INTR_CAUSE_OFF_1   0x000c
#define MPSC_INTR_CAUSE_RCC (1<<6)

static void __iomem *mpsc_base;
static void __iomem *mpsc_intr_cause;

static void mv64x60_udbg_putc(char c)
{
    if (c == '\n')
        mv64x60_udbg_putc('\r');

    while(in_le32(mpsc_base + MPSC_0_CR2_OFFSET) & MPSC_CHR_2_TCS)
        ;
    out_le32(mpsc_base + MPSC_0_CR1_OFFSET, c);
    out_le32(mpsc_base + MPSC_0_CR2_OFFSET, MPSC_CHR_2_TCS);
}

static int mv64x60_udbg_testc(void)
{
    return (in_le32(mpsc_intr_cause) & MPSC_INTR_CAUSE_RCC) != 0;
}

static int mv64x60_udbg_getc(void)
{
    int cause = 0;
    int c;

    while (!mv64x60_udbg_testc())
        ;

    c = in_8(mpsc_base + MPSC_0_CHR_10_OFFSET + 2);
    out_8(mpsc_base + MPSC_0_CHR_10_OFFSET + 2, c);
    out_le32(mpsc_intr_cause, cause & ~MPSC_INTR_CAUSE_RCC);
    return c;
}

static int mv64x60_udbg_getc_poll(void)
{
    if (!mv64x60_udbg_testc())
        return -1;

    return mv64x60_udbg_getc();
}

static void mv64x60_udbg_init(void)
{
    struct device_node *np, *mpscintr, *stdout = NULL;
    const char *path;
    const phandle *ph;
    struct resource r[2];
    const int *block_index;
    int intr_cause_offset;
    int err;

    path = of_get_property(of_chosen, "linux,stdout-path", NULL);
    if (!path)
        return;

    stdout = of_find_node_by_path(path);
    if (!stdout)
        return;

    for_each_compatible_node(np, "serial", "marvell,mv64360-mpsc") {
        if (np == stdout)
            break;
    }

    of_node_put(stdout);
    if (!np)
        return;

    block_index = of_get_property(np, "cell-index", NULL);
    if (!block_index)
        goto error;

    switch (*block_index) {
    case 0:
        intr_cause_offset = MPSC_INTR_CAUSE_OFF_0;
        break;
    case 1:
        intr_cause_offset = MPSC_INTR_CAUSE_OFF_1;
        break;
    default:
        goto error;
    }

    err = of_address_to_resource(np, 0, &r[0]);
    if (err)
        goto error;

    ph = of_get_property(np, "mpscintr", NULL);
    mpscintr = of_find_node_by_phandle(*ph);
    if (!mpscintr)
        goto error;

    err = of_address_to_resource(mpscintr, 0, &r[1]);
    of_node_put(mpscintr);
    if (err)
        goto error;

    of_node_put(np);

    mpsc_base = ioremap(r[0].start, resource_size(&r[0]));
    if (!mpsc_base)
        return;

    mpsc_intr_cause = ioremap(r[1].start, resource_size(&r[1]));
    if (!mpsc_intr_cause) {
        iounmap(mpsc_base);
        return;
    }
    mpsc_intr_cause += intr_cause_offset;

    udbg_putc = mv64x60_udbg_putc;
    udbg_getc = mv64x60_udbg_getc;
    udbg_getc_poll = mv64x60_udbg_getc_poll;

    return;

error:
    of_node_put(np);
}

void mv64x60_init_early(void)
{
    mv64x60_udbg_init();
}