cx23885-f300.c

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/*
 * Driver for Silicon Labs C8051F300 microcontroller.
 *
 * It is used for LNB power control in TeVii S470,
 * TBS 6920 PCIe DVB-S2 cards.
 *
 * Microcontroller connected to cx23885 GPIO pins:
 * GPIO0 - data     - P0.3 F300
 * GPIO1 - reset    - P0.2 F300
 * GPIO2 - clk      - P0.1 F300
 * GPIO3 - busy     - P0.0 F300
 *
 * Copyright (C) 2009 Igor M. Liplianin <[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 "cx23885.h"

#define F300_DATA   GPIO_0
#define F300_RESET  GPIO_1
#define F300_CLK    GPIO_2
#define F300_BUSY   GPIO_3

static void f300_set_line(struct cx23885_dev *dev, u32 line, u8 lvl)
{
    cx23885_gpio_enable(dev, line, 1);
    if (lvl == 1)
        cx23885_gpio_set(dev, line);
    else
        cx23885_gpio_clear(dev, line);
}

static u8 f300_get_line(struct cx23885_dev *dev, u32 line)
{
    cx23885_gpio_enable(dev, line, 0);

    return cx23885_gpio_get(dev, line);
}

static void f300_send_byte(struct cx23885_dev *dev, u8 dta)
{
    u8 i;

    for (i = 0; i < 8; i++) {
        f300_set_line(dev, F300_CLK, 0);
        udelay(30);
        f300_set_line(dev, F300_DATA, (dta & 0x80) >> 7);/* msb first */
        udelay(30);
        dta <<= 1;
        f300_set_line(dev, F300_CLK, 1);
        udelay(30);
    }
}

static u8 f300_get_byte(struct cx23885_dev *dev)
{
    u8 i, dta = 0;

    for (i = 0; i < 8; i++) {
        f300_set_line(dev, F300_CLK, 0);
        udelay(30);
        dta <<= 1;
        f300_set_line(dev, F300_CLK, 1);
        udelay(30);
        dta |= f300_get_line(dev, F300_DATA);/* msb first */

    }

    return dta;
}

static u8 f300_xfer(struct dvb_frontend *fe, u8 *buf)
{
    struct cx23885_tsport *port = fe->dvb->priv;
    struct cx23885_dev *dev = port->dev;
    u8 i, temp, ret = 0;

    temp = buf[0];
    for (i = 0; i < buf[0]; i++)
        temp += buf[i + 1];
    temp = (~temp + 1);/* get check sum */
    buf[1 + buf[0]] = temp;

    f300_set_line(dev, F300_RESET, 1);
    f300_set_line(dev, F300_CLK, 1);
    udelay(30);
    f300_set_line(dev, F300_DATA, 1);
    msleep(1);

    /* question: */
    f300_set_line(dev, F300_RESET, 0);/* begin to send data */
    msleep(1);

    f300_send_byte(dev, 0xe0);/* the slave address is 0xe0, write */
    msleep(1);

    temp = buf[0];
    temp += 2;
    for (i = 0; i < temp; i++)
        f300_send_byte(dev, buf[i]);

    f300_set_line(dev, F300_RESET, 1);/* sent data over */
    f300_set_line(dev, F300_DATA, 1);

    /* answer: */
    temp = 0;
    for (i = 0; ((i < 8) & (temp == 0)); i++) {
        msleep(1);
        if (f300_get_line(dev, F300_BUSY) == 0)
            temp = 1;
    }

    if (i > 7) {
        printk(KERN_ERR "%s: timeout, the slave no response\n",
                                __func__);
        ret = 1; /* timeout, the slave no response */
    } else { /* the slave not busy, prepare for getting data */
        f300_set_line(dev, F300_RESET, 0);/*ready...*/
        msleep(1);
        f300_send_byte(dev, 0xe1);/* 0xe1 is Read */
        msleep(1);
        temp = f300_get_byte(dev);/*get the data length */
        if (temp > 14)
            temp = 14;

        for (i = 0; i < (temp + 1); i++)
            f300_get_byte(dev);/* get data to empty buffer */

        f300_set_line(dev, F300_RESET, 1);/* received data over */
        f300_set_line(dev, F300_DATA, 1);
    }

    return ret;
}

int f300_set_voltage(struct dvb_frontend *fe, fe_sec_voltage_t voltage)
{
    u8 buf[16];

    buf[0] = 0x05;
    buf[1] = 0x38;/* write port */
    buf[2] = 0x01;/* A port, lnb power */

    switch (voltage) {
    case SEC_VOLTAGE_13:
        buf[3] = 0x01;/* power on */
        buf[4] = 0x02;/* B port, H/V */
        buf[5] = 0x00;/*13V v*/
        break;
    case SEC_VOLTAGE_18:
        buf[3] = 0x01;
        buf[4] = 0x02;
        buf[5] = 0x01;/* 18V h*/
        break;
    case SEC_VOLTAGE_OFF:
        buf[3] = 0x00;/* power off */
        buf[4] = 0x00;
        buf[5] = 0x00;
        break;
    }

    return f300_xfer(fe, buf);
}