mantis_uart.c

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/*
    Mantis PCI bridge driver

    Copyright (C) Manu Abraham ([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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <asm/io.h>

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/interrupt.h>

#include "dmxdev.h"
#include "dvbdev.h"
#include "dvb_demux.h"
#include "dvb_frontend.h"
#include "dvb_net.h"

#include "mantis_common.h"
#include "mantis_reg.h"
#include "mantis_uart.h"

struct mantis_uart_params {
    enum mantis_baud    baud_rate;
    enum mantis_parity  parity;
};

static struct {
    char string[7];
} rates[5] = {
    { "9600" },
    { "19200" },
    { "38400" },
    { "57600" },
    { "115200" }
};

static struct {
    char string[5];
} parity[3] = {
    { "NONE" },
    { "ODD" },
    { "EVEN" }
};

#define UART_MAX_BUF            16

int mantis_uart_read(struct mantis_pci *mantis, u8 *data)
{
    struct mantis_hwconfig *config = mantis->hwconfig;
    u32 stat = 0, i;

    /* get data */
    for (i = 0; i < (config->bytes + 1); i++) {

        stat = mmread(MANTIS_UART_STAT);

        if (stat & MANTIS_UART_RXFIFO_FULL) {
            dprintk(MANTIS_ERROR, 1, "RX Fifo FULL");
        }
        data[i] = mmread(MANTIS_UART_RXD) & 0x3f;

        dprintk(MANTIS_DEBUG, 1, "Reading ... <%02x>", data[i] & 0x3f);

        if (data[i] & (1 << 7)) {
            dprintk(MANTIS_ERROR, 1, "UART framing error");
            return -EINVAL;
        }
        if (data[i] & (1 << 6)) {
            dprintk(MANTIS_ERROR, 1, "UART parity error");
            return -EINVAL;
        }
    }

    return 0;
}

static void mantis_uart_work(struct work_struct *work)
{
    struct mantis_pci *mantis = container_of(work, struct mantis_pci, uart_work);
    struct mantis_hwconfig *config = mantis->hwconfig;
    u8 buf[16];
    int i;

    mantis_uart_read(mantis, buf);

    for (i = 0; i < (config->bytes + 1); i++)
        dprintk(MANTIS_INFO, 1, "UART BUF:%d <%02x> ", i, buf[i]);

    dprintk(MANTIS_DEBUG, 0, "\n");
}

static int mantis_uart_setup(struct mantis_pci *mantis,
                 struct mantis_uart_params *params)
{
    u32 reg;

    mmwrite((mmread(MANTIS_UART_CTL) | (params->parity & 0x3)), MANTIS_UART_CTL);

    reg = mmread(MANTIS_UART_BAUD);

    switch (params->baud_rate) {
    case MANTIS_BAUD_9600:
        reg |= 0xd8;
        break;
    case MANTIS_BAUD_19200:
        reg |= 0x6c;
        break;
    case MANTIS_BAUD_38400:
        reg |= 0x36;
        break;
    case MANTIS_BAUD_57600:
        reg |= 0x23;
        break;
    case MANTIS_BAUD_115200:
        reg |= 0x11;
        break;
    default:
        return -EINVAL;
    }

    mmwrite(reg, MANTIS_UART_BAUD);

    return 0;
}

int mantis_uart_init(struct mantis_pci *mantis)
{
    struct mantis_hwconfig *config = mantis->hwconfig;
    struct mantis_uart_params params;

    /* default parity: */
    params.baud_rate = config->baud_rate;
    params.parity = config->parity;
    dprintk(MANTIS_INFO, 1, "Initializing UART @ %sbps parity:%s",
        rates[params.baud_rate].string,
        parity[params.parity].string);

    init_waitqueue_head(&mantis->uart_wq);
    spin_lock_init(&mantis->uart_lock);

    INIT_WORK(&mantis->uart_work, mantis_uart_work);

    /* disable interrupt */
    mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);

    mantis_uart_setup(mantis, &params);

    /* default 1 byte */
    mmwrite((mmread(MANTIS_UART_BAUD) | (config->bytes << 8)), MANTIS_UART_BAUD);

    /* flush buffer */
    mmwrite((mmread(MANTIS_UART_CTL) | MANTIS_UART_RXFLUSH), MANTIS_UART_CTL);

    /* enable interrupt */
    mmwrite(mmread(MANTIS_INT_MASK) | 0x800, MANTIS_INT_MASK);
    mmwrite(mmread(MANTIS_UART_CTL) | MANTIS_UART_RXINT, MANTIS_UART_CTL);

    schedule_work(&mantis->uart_work);
    dprintk(MANTIS_DEBUG, 1, "UART successfully initialized");

    return 0;
}
EXPORT_SYMBOL_GPL(mantis_uart_init);

void mantis_uart_exit(struct mantis_pci *mantis)
{
    /* disable interrupt */
    mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
    flush_work(&mantis->uart_work);
}
EXPORT_SYMBOL_GPL(mantis_uart_exit);