mpsc.c

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/*
 * MPSC/UART driver for the Marvell mv64360, mv64460, ...
 *
 * Author: Mark A. Greer <[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 <stdarg.h>
#include <stddef.h>
#include "types.h"
#include "string.h"
#include "stdio.h"
#include "io.h"
#include "ops.h"


#define MPSC_CHR_1      0x000c

#define MPSC_CHR_2      0x0010
#define MPSC_CHR_2_TA       (1<<7)
#define MPSC_CHR_2_TCS      (1<<9)
#define MPSC_CHR_2_RA       (1<<23)
#define MPSC_CHR_2_CRD      (1<<25)
#define MPSC_CHR_2_EH       (1<<31)

#define MPSC_CHR_4      0x0018
#define MPSC_CHR_4_Z        (1<<29)

#define MPSC_CHR_5      0x001c
#define MPSC_CHR_5_CTL1_INTR    (1<<12)
#define MPSC_CHR_5_CTL1_VALID   (1<<15)

#define MPSC_CHR_10     0x0030

#define MPSC_INTR_CAUSE     0x0000
#define MPSC_INTR_CAUSE_RCC (1<<6)
#define MPSC_INTR_MASK      0x0080

#define SDMA_SDCM       0x0008
#define SDMA_SDCM_AR        (1<<15)
#define SDMA_SDCM_AT        (1<<31)

static volatile char *mpsc_base;
static volatile char *mpscintr_base;
static u32 chr1, chr2;

static int mpsc_open(void)
{
    chr1 = in_le32((u32 *)(mpsc_base + MPSC_CHR_1)) & 0x00ff0000;
    chr2 = in_le32((u32 *)(mpsc_base + MPSC_CHR_2)) & ~(MPSC_CHR_2_TA
            | MPSC_CHR_2_TCS | MPSC_CHR_2_RA | MPSC_CHR_2_CRD
            | MPSC_CHR_2_EH);
    out_le32((u32 *)(mpsc_base + MPSC_CHR_4), MPSC_CHR_4_Z);
    out_le32((u32 *)(mpsc_base + MPSC_CHR_5),
            MPSC_CHR_5_CTL1_INTR | MPSC_CHR_5_CTL1_VALID);
    out_le32((u32 *)(mpsc_base + MPSC_CHR_2), chr2 | MPSC_CHR_2_EH);
    return 0;
}

static void mpsc_putc(unsigned char c)
{
    while (in_le32((u32 *)(mpsc_base + MPSC_CHR_2)) & MPSC_CHR_2_TCS);

    out_le32((u32 *)(mpsc_base + MPSC_CHR_1), chr1 | c);
    out_le32((u32 *)(mpsc_base + MPSC_CHR_2), chr2 | MPSC_CHR_2_TCS);
}

static unsigned char mpsc_getc(void)
{
    u32 cause = 0;
    unsigned char c;

    while (!(cause & MPSC_INTR_CAUSE_RCC))
        cause = in_le32((u32 *)(mpscintr_base + MPSC_INTR_CAUSE));

    c = in_8((u8 *)(mpsc_base + MPSC_CHR_10 + 2));
    out_8((u8 *)(mpsc_base + MPSC_CHR_10 + 2), c);
    out_le32((u32 *)(mpscintr_base + MPSC_INTR_CAUSE),
            cause & ~MPSC_INTR_CAUSE_RCC);

    return c;
}

static u8 mpsc_tstc(void)
{
    return (u8)((in_le32((u32 *)(mpscintr_base + MPSC_INTR_CAUSE))
                & MPSC_INTR_CAUSE_RCC) != 0);
}

static void mpsc_stop_dma(volatile char *sdma_base)
{
    out_le32((u32 *)(mpsc_base + MPSC_CHR_2),MPSC_CHR_2_TA | MPSC_CHR_2_RA);
    out_le32((u32 *)(sdma_base + SDMA_SDCM), SDMA_SDCM_AR | SDMA_SDCM_AT);

    while ((in_le32((u32 *)(sdma_base + SDMA_SDCM))
                & (SDMA_SDCM_AR | SDMA_SDCM_AT)) != 0)
        udelay(100);
}

static volatile char *mpsc_get_virtreg_of_phandle(void *devp, char *prop)
{
    void *v;
    int n;

    n = getprop(devp, prop, &v, sizeof(v));
    if (n != sizeof(v))
        goto err_out;

    devp = find_node_by_linuxphandle((u32)v);
    if (devp == NULL)
        goto err_out;

    n = getprop(devp, "virtual-reg", &v, sizeof(v));
    if (n == sizeof(v))
        return v;

err_out:
    return NULL;
}

int mpsc_console_init(void *devp, struct serial_console_data *scdp)
{
    void *v;
    int n, reg_set;
    volatile char *sdma_base;

    n = getprop(devp, "virtual-reg", &v, sizeof(v));
    if (n != sizeof(v))
        goto err_out;
    mpsc_base = v;

    sdma_base = mpsc_get_virtreg_of_phandle(devp, "sdma");
    if (sdma_base == NULL)
        goto err_out;

    mpscintr_base = mpsc_get_virtreg_of_phandle(devp, "mpscintr");
    if (mpscintr_base == NULL)
        goto err_out;

    n = getprop(devp, "cell-index", &v, sizeof(v));
    if (n != sizeof(v))
        goto err_out;
    reg_set = (int)v;

    mpscintr_base += (reg_set == 0) ? 0x4 : 0xc;

    /* Make sure the mpsc ctlrs are shutdown */
    out_le32((u32 *)(mpscintr_base + MPSC_INTR_CAUSE), 0);
    out_le32((u32 *)(mpscintr_base + MPSC_INTR_CAUSE), 0);
    out_le32((u32 *)(mpscintr_base + MPSC_INTR_MASK), 0);
    out_le32((u32 *)(mpscintr_base + MPSC_INTR_MASK), 0);

    mpsc_stop_dma(sdma_base);

    scdp->open = mpsc_open;
    scdp->putc = mpsc_putc;
    scdp->getc = mpsc_getc;
    scdp->tstc = mpsc_tstc;
    scdp->close = NULL;

    return 0;

err_out:
    return -1;
}