// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * STK1160 driver
 *
 * Copyright (C) 2012 Ezequiel Garcia
 * <elezegarcia--a.t--gmail.com>
 *
 * Copyright (C) 2016 Marcel Hasler
 * <mahasler--a.t--gmail.com>
 *
 * Based on Easycap driver by R.M. Thomas
 *      Copyright (C) 2010 R.M. Thomas
 *      <rmthomas--a.t--sciolus.org>
 */

#include <linux/delay.h>

#include "stk1160.h"
#include "stk1160-reg.h"

static int stk1160_ac97_wait_transfer_complete(struct stk1160 *dev)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(STK1160_AC97_TIMEOUT);
        u8 value;

        /* Wait for AC97 transfer to complete */
        while (time_is_after_jiffies(timeout)) {
                stk1160_read_reg(dev, STK1160_AC97CTL_0, &value);

                if (!(value & (STK1160_AC97CTL_0_CR | STK1160_AC97CTL_0_CW)))
                        return 0;

                usleep_range(50, 100);
        }

        stk1160_err("AC97 transfer took too long, this should never happen!");
        return -EBUSY;
}

static void stk1160_write_ac97(struct stk1160 *dev, u16 reg, u16 value)
{
        /* Set codec register address */
        stk1160_write_reg(dev, STK1160_AC97_ADDR, reg);

        /* Set codec command */
        stk1160_write_reg(dev, STK1160_AC97_CMD, value & 0xff);
        stk1160_write_reg(dev, STK1160_AC97_CMD + 1, (value & 0xff00) >> 8);

        /* Set command write bit to initiate write operation */
        stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c);

        /* Wait for command write bit to be cleared */
        stk1160_ac97_wait_transfer_complete(dev);
}

#ifdef DEBUG
static u16 stk1160_read_ac97(struct stk1160 *dev, u16 reg)
{
        u8 vall = 0;
        u8 valh = 0;

        /* Set codec register address */
        stk1160_write_reg(dev, STK1160_AC97_ADDR, reg);

        /* Set command read bit to initiate read operation */
        stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8b);

        /* Wait for command read bit to be cleared */
        if (stk1160_ac97_wait_transfer_complete(dev) < 0)
                return 0;


        /* Retrieve register value */
        stk1160_read_reg(dev, STK1160_AC97_CMD, &vall);
        stk1160_read_reg(dev, STK1160_AC97_CMD + 1, &valh);

        return (valh << 8) | vall;
}

void stk1160_ac97_dump_regs(struct stk1160 *dev)
{
        u16 value;

        value = stk1160_read_ac97(dev, 0x12); /* CD volume */
        stk1160_dbg("0x12 == 0x%04x", value);

        value = stk1160_read_ac97(dev, 0x10); /* Line-in volume */
        stk1160_dbg("0x10 == 0x%04x", value);

        value = stk1160_read_ac97(dev, 0x0e); /* MIC volume (mono) */
        stk1160_dbg("0x0e == 0x%04x", value);

        value = stk1160_read_ac97(dev, 0x16); /* Aux volume */
        stk1160_dbg("0x16 == 0x%04x", value);

        value = stk1160_read_ac97(dev, 0x1a); /* Record select */
        stk1160_dbg("0x1a == 0x%04x", value);

        value = stk1160_read_ac97(dev, 0x02); /* Master volume */
        stk1160_dbg("0x02 == 0x%04x", value);

        value = stk1160_read_ac97(dev, 0x1c); /* Record gain */
        stk1160_dbg("0x1c == 0x%04x", value);
}
#endif

static int stk1160_has_audio(struct stk1160 *dev)
{
        u8 value;

        stk1160_read_reg(dev, STK1160_POSV_L, &value);
        return !(value & STK1160_POSV_L_ACDOUT);
}

static int stk1160_has_ac97(struct stk1160 *dev)
{
        u8 value;

        stk1160_read_reg(dev, STK1160_POSV_L, &value);
        return !(value & STK1160_POSV_L_ACSYNC);
}

void stk1160_ac97_setup(struct stk1160 *dev)
{
        if (!stk1160_has_audio(dev)) {
                stk1160_info("Device doesn't support audio, skipping AC97 setup.");
                return;
        }

        if (!stk1160_has_ac97(dev)) {
                stk1160_info("Device uses internal 8-bit ADC, skipping AC97 setup.");
                return;
        }

        /* Two-step reset AC97 interface and hardware codec */
        stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x94);
        stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c);

        /* Set 16-bit audio data and choose L&R channel*/
        stk1160_write_reg(dev, STK1160_AC97CTL_1 + 2, 0x01);
        stk1160_write_reg(dev, STK1160_AC97CTL_1 + 3, 0x00);

        /* Setup channels */
        stk1160_write_ac97(dev, 0x12, 0x8808); /* CD volume */
        stk1160_write_ac97(dev, 0x10, 0x0808); /* Line-in volume */
        stk1160_write_ac97(dev, 0x0e, 0x0008); /* MIC volume (mono) */
        stk1160_write_ac97(dev, 0x16, 0x0808); /* Aux volume */
        stk1160_write_ac97(dev, 0x1a, 0x0404); /* Record select */
        stk1160_write_ac97(dev, 0x02, 0x0000); /* Master volume */
        stk1160_write_ac97(dev, 0x1c, 0x0808); /* Record gain */

#ifdef DEBUG
        stk1160_ac97_dump_regs(dev);
#endif
}