// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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 <liplianin@me.by>
 */

#include "cx23885.h"
#include "cx23885-f300.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) {
                pr_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, enum fe_sec_voltage 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);
}