// SPDX-License-Identifier: GPL-2.0-only
/*
 * Regmap support for HD-audio verbs
 *
 * A virtual register is translated to one or more hda verbs for write,
 * vice versa for read.
 *
 * A few limitations:
 * - Provided for not all verbs but only subset standard non-volatile verbs.
 * - For reading, only AC_VERB_GET_* variants can be used.
 * - For writing, mapped to the *corresponding* AC_VERB_SET_* variants,
 *   so can't handle asymmetric verbs for read and write
 */

#include <linux/slab.h>
#include <linux/device.h>
#include <linux/regmap.h>
#include <linux/export.h>
#include <linux/pm.h>
#include <sound/core.h>
#include <sound/hdaudio.h>
#include <sound/hda_regmap.h>
#include "local.h"

static int codec_pm_lock(struct hdac_device *codec)
{
        return snd_hdac_keep_power_up(codec);
}

static void codec_pm_unlock(struct hdac_device *codec, int lock)
{
        if (lock == 1)
                snd_hdac_power_down_pm(codec);
}

#define get_verb(reg)   (((reg) >> 8) & 0xfff)

static bool hda_volatile_reg(struct device *dev, unsigned int reg)
{
        struct hdac_device *codec = dev_to_hdac_dev(dev);
        unsigned int verb = get_verb(reg);

        switch (verb) {
        case AC_VERB_GET_PROC_COEF:
                return !codec->cache_coef;
        case AC_VERB_GET_COEF_INDEX:
        case AC_VERB_GET_PROC_STATE:
        case AC_VERB_GET_POWER_STATE:
        case AC_VERB_GET_PIN_SENSE:
        case AC_VERB_GET_HDMI_DIP_SIZE:
        case AC_VERB_GET_HDMI_ELDD:
        case AC_VERB_GET_HDMI_DIP_INDEX:
        case AC_VERB_GET_HDMI_DIP_DATA:
        case AC_VERB_GET_HDMI_DIP_XMIT:
        case AC_VERB_GET_HDMI_CP_CTRL:
        case AC_VERB_GET_HDMI_CHAN_SLOT:
        case AC_VERB_GET_DEVICE_SEL:
        case AC_VERB_GET_DEVICE_LIST:   /* read-only volatile */
                return true;
        }

        return false;
}

static bool hda_writeable_reg(struct device *dev, unsigned int reg)
{
        struct hdac_device *codec = dev_to_hdac_dev(dev);
        unsigned int verb = get_verb(reg);
        const unsigned int *v;
        int i;

        snd_array_for_each(&codec->vendor_verbs, i, v) {
                if (verb == *v)
                        return true;
        }

        if (codec->caps_overwriting)
                return true;

        switch (verb & 0xf00) {
        case AC_VERB_GET_STREAM_FORMAT:
        case AC_VERB_GET_AMP_GAIN_MUTE:
                return true;
        case AC_VERB_GET_PROC_COEF:
                return codec->cache_coef;
        case 0xf00:
                break;
        default:
                return false;
        }

        switch (verb) {
        case AC_VERB_GET_CONNECT_SEL:
        case AC_VERB_GET_SDI_SELECT:
        case AC_VERB_GET_PIN_WIDGET_CONTROL:
        case AC_VERB_GET_UNSOLICITED_RESPONSE: /* only as SET_UNSOLICITED_ENABLE */
        case AC_VERB_GET_BEEP_CONTROL:
        case AC_VERB_GET_EAPD_BTLENABLE:
        case AC_VERB_GET_DIGI_CONVERT_1:
        case AC_VERB_GET_DIGI_CONVERT_2: /* only for beep control */
        case AC_VERB_GET_VOLUME_KNOB_CONTROL:
        case AC_VERB_GET_GPIO_MASK:
        case AC_VERB_GET_GPIO_DIRECTION:
        case AC_VERB_GET_GPIO_DATA: /* not for volatile read */
        case AC_VERB_GET_GPIO_WAKE_MASK:
        case AC_VERB_GET_GPIO_UNSOLICITED_RSP_MASK:
        case AC_VERB_GET_GPIO_STICKY_MASK:
                return true;
        }

        return false;
}

static bool hda_readable_reg(struct device *dev, unsigned int reg)
{
        struct hdac_device *codec = dev_to_hdac_dev(dev);
        unsigned int verb = get_verb(reg);

        if (codec->caps_overwriting)
                return true;

        switch (verb) {
        case AC_VERB_PARAMETERS:
        case AC_VERB_GET_CONNECT_LIST:
        case AC_VERB_GET_SUBSYSTEM_ID:
                return true;
        /* below are basically writable, but disabled for reducing unnecessary
         * writes at sync
         */
        case AC_VERB_GET_CONFIG_DEFAULT: /* usually just read */
        case AC_VERB_GET_CONV: /* managed in PCM code */
        case AC_VERB_GET_CVT_CHAN_COUNT: /* managed in HDMI CA code */
                return true;
        }

        return hda_writeable_reg(dev, reg);
}

/*
 * Stereo amp pseudo register:
 * for making easier to handle the stereo volume control, we provide a
 * fake register to deal both left and right channels by a single
 * (pseudo) register access.  A verb consisting of SET_AMP_GAIN with
 * *both* SET_LEFT and SET_RIGHT bits takes a 16bit value, the lower 8bit
 * for the left and the upper 8bit for the right channel.
 */
static bool is_stereo_amp_verb(unsigned int reg)
{
        if (((reg >> 8) & 0x700) != AC_VERB_SET_AMP_GAIN_MUTE)
                return false;
        return (reg & (AC_AMP_SET_LEFT | AC_AMP_SET_RIGHT)) ==
                (AC_AMP_SET_LEFT | AC_AMP_SET_RIGHT);
}

/* read a pseudo stereo amp register (16bit left+right) */
static int hda_reg_read_stereo_amp(struct hdac_device *codec,
                                   unsigned int reg, unsigned int *val)
{
        unsigned int left, right;
        int err;

        reg &= ~(AC_AMP_SET_LEFT | AC_AMP_SET_RIGHT);
        err = snd_hdac_exec_verb(codec, reg | AC_AMP_GET_LEFT, 0, &left);
        if (err < 0)
                return err;
        err = snd_hdac_exec_verb(codec, reg | AC_AMP_GET_RIGHT, 0, &right);
        if (err < 0)
                return err;
        *val = left | (right << 8);
        return 0;
}

/* write a pseudo stereo amp register (16bit left+right) */
static int hda_reg_write_stereo_amp(struct hdac_device *codec,
                                    unsigned int reg, unsigned int val)
{
        int err;
        unsigned int verb, left, right;

        verb = AC_VERB_SET_AMP_GAIN_MUTE << 8;
        if (reg & AC_AMP_GET_OUTPUT)
                verb |= AC_AMP_SET_OUTPUT;
        else
                verb |= AC_AMP_SET_INPUT | ((reg & 0xf) << 8);
        reg = (reg & ~0xfffff) | verb;

        left = val & 0xff;
        right = (val >> 8) & 0xff;
        if (left == right) {
                reg |= AC_AMP_SET_LEFT | AC_AMP_SET_RIGHT;
                return snd_hdac_exec_verb(codec, reg | left, 0, NULL);
        }

        err = snd_hdac_exec_verb(codec, reg | AC_AMP_SET_LEFT | left, 0, NULL);
        if (err < 0)
                return err;
        err = snd_hdac_exec_verb(codec, reg | AC_AMP_SET_RIGHT | right, 0, NULL);
        if (err < 0)
                return err;
        return 0;
}

/* read a pseudo coef register (16bit) */
static int hda_reg_read_coef(struct hdac_device *codec, unsigned int reg,
                             unsigned int *val)
{
        unsigned int verb;
        int err;

        if (!codec->cache_coef)
                return -EINVAL;
        /* LSB 8bit = coef index */
        verb = (reg & ~0xfff00) | (AC_VERB_SET_COEF_INDEX << 8);
        err = snd_hdac_exec_verb(codec, verb, 0, NULL);
        if (err < 0)
                return err;
        verb = (reg & ~0xfffff) | (AC_VERB_GET_COEF_INDEX << 8);
        return snd_hdac_exec_verb(codec, verb, 0, val);
}

/* write a pseudo coef register (16bit) */
static int hda_reg_write_coef(struct hdac_device *codec, unsigned int reg,
                              unsigned int val)
{
        unsigned int verb;
        int err;

        if (!codec->cache_coef)
                return -EINVAL;
        /* LSB 8bit = coef index */
        verb = (reg & ~0xfff00) | (AC_VERB_SET_COEF_INDEX << 8);
        err = snd_hdac_exec_verb(codec, verb, 0, NULL);
        if (err < 0)
                return err;
        verb = (reg & ~0xfffff) | (AC_VERB_GET_COEF_INDEX << 8) |
                (val & 0xffff);
        return snd_hdac_exec_verb(codec, verb, 0, NULL);
}

static int hda_reg_read(void *context, unsigned int reg, unsigned int *val)
{
        struct hdac_device *codec = context;
        int verb = get_verb(reg);
        int err;
        int pm_lock = 0;

        if (verb != AC_VERB_GET_POWER_STATE) {
                pm_lock = codec_pm_lock(codec);
                if (pm_lock < 0)
                        return -EAGAIN;
        }
        reg |= (codec->addr << 28);
        if (is_stereo_amp_verb(reg)) {
                err = hda_reg_read_stereo_amp(codec, reg, val);
                goto out;
        }
        if (verb == AC_VERB_GET_PROC_COEF) {
                err = hda_reg_read_coef(codec, reg, val);
                goto out;
        }
        if ((verb & 0x700) == AC_VERB_SET_AMP_GAIN_MUTE)
                reg &= ~AC_AMP_FAKE_MUTE;

        err = snd_hdac_exec_verb(codec, reg, 0, val);
        if (err < 0)
                goto out;
        /* special handling for asymmetric reads */
        if (verb == AC_VERB_GET_POWER_STATE) {
                if (*val & AC_PWRST_ERROR)
                        *val = -1;
                else /* take only the actual state */
                        *val = (*val >> 4) & 0x0f;
        }
 out:
        codec_pm_unlock(codec, pm_lock);
        return err;
}

static int hda_reg_write(void *context, unsigned int reg, unsigned int val)
{
        struct hdac_device *codec = context;
        unsigned int verb;
        int i, bytes, err;
        int pm_lock = 0;

        if (codec->caps_overwriting)
                return 0;

        reg &= ~0x00080000U; /* drop GET bit */
        reg |= (codec->addr << 28);
        verb = get_verb(reg);

        if (verb != AC_VERB_SET_POWER_STATE) {
                pm_lock = codec_pm_lock(codec);
                if (pm_lock < 0)
                        return codec->lazy_cache ? 0 : -EAGAIN;
        }

        if (is_stereo_amp_verb(reg)) {
                err = hda_reg_write_stereo_amp(codec, reg, val);
                goto out;
        }

        if (verb == AC_VERB_SET_PROC_COEF) {
                err = hda_reg_write_coef(codec, reg, val);
                goto out;
        }

        switch (verb & 0xf00) {
        case AC_VERB_SET_AMP_GAIN_MUTE:
                if ((reg & AC_AMP_FAKE_MUTE) && (val & AC_AMP_MUTE))
                        val = 0;
                verb = AC_VERB_SET_AMP_GAIN_MUTE;
                if (reg & AC_AMP_GET_LEFT)
                        verb |= AC_AMP_SET_LEFT >> 8;
                else
                        verb |= AC_AMP_SET_RIGHT >> 8;
                if (reg & AC_AMP_GET_OUTPUT) {
                        verb |= AC_AMP_SET_OUTPUT >> 8;
                } else {
                        verb |= AC_AMP_SET_INPUT >> 8;
                        verb |= reg & 0xf;
                }
                break;
        }

        switch (verb) {
        case AC_VERB_SET_DIGI_CONVERT_1:
                bytes = 2;
                break;
        case AC_VERB_SET_CONFIG_DEFAULT_BYTES_0:
                bytes = 4;
                break;
        default:
                bytes = 1;
                break;
        }

        for (i = 0; i < bytes; i++) {
                reg &= ~0xfffff;
                reg |= (verb + i) << 8 | ((val >> (8 * i)) & 0xff);
                err = snd_hdac_exec_verb(codec, reg, 0, NULL);
                if (err < 0)
                        goto out;
        }

 out:
        codec_pm_unlock(codec, pm_lock);
        return err;
}

static const struct regmap_config hda_regmap_cfg = {
        .name = "hdaudio",
        .reg_bits = 32,
        .val_bits = 32,
        .max_register = 0xfffffff,
        .writeable_reg = hda_writeable_reg,
        .readable_reg = hda_readable_reg,
        .volatile_reg = hda_volatile_reg,
        .cache_type = REGCACHE_MAPLE,
        .reg_read = hda_reg_read,
        .reg_write = hda_reg_write,
        .use_single_read = true,
        .use_single_write = true,
        .disable_locking = true,
};

/**
 * snd_hdac_regmap_init - Initialize regmap for HDA register accesses
 * @codec: the codec object
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_regmap_init(struct hdac_device *codec)
{
        struct regmap *regmap;

        regmap = regmap_init(&codec->dev, NULL, codec, &hda_regmap_cfg);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);
        codec->regmap = regmap;
        snd_array_init(&codec->vendor_verbs, sizeof(unsigned int), 8);
        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_init);

/**
 * snd_hdac_regmap_exit - Release the regmap from HDA codec
 * @codec: the codec object
 */
void snd_hdac_regmap_exit(struct hdac_device *codec)
{
        if (codec->regmap) {
                regmap_exit(codec->regmap);
                codec->regmap = NULL;
                snd_array_free(&codec->vendor_verbs);
        }
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_exit);

/**
 * snd_hdac_regmap_add_vendor_verb - add a vendor-specific verb to regmap
 * @codec: the codec object
 * @verb: verb to allow accessing via regmap
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_regmap_add_vendor_verb(struct hdac_device *codec,
                                    unsigned int verb)
{
        unsigned int *p = snd_array_new(&codec->vendor_verbs);

        if (!p)
                return -ENOMEM;
        *p = verb | 0x800; /* set GET bit */
        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_add_vendor_verb);

/*
 * helper functions
 */

/* write a pseudo-register value (w/o power sequence) */
static int reg_raw_write(struct hdac_device *codec, unsigned int reg,
                         unsigned int val)
{
        guard(mutex)(&codec->regmap_lock);
        if (!codec->regmap)
                return hda_reg_write(codec, reg, val);
        else
                return regmap_write(codec->regmap, reg, val);
}

/* a helper macro to call @func_call; retry with power-up if failed */
#define CALL_RAW_FUNC(codec, func_call)                         \
        ({                                                      \
                int _err = func_call;                           \
                if (_err == -EAGAIN) {                          \
                        _err = snd_hdac_power_up_pm(codec);     \
                        if (_err >= 0)                          \
                                _err = func_call;               \
                        snd_hdac_power_down_pm(codec);          \
                }                                               \
                _err;})

/**
 * snd_hdac_regmap_write_raw - write a pseudo register with power mgmt
 * @codec: the codec object
 * @reg: pseudo register
 * @val: value to write
 *
 * Returns zero if successful or a negative error code.
 */
int snd_hdac_regmap_write_raw(struct hdac_device *codec, unsigned int reg,
                              unsigned int val)
{
        return CALL_RAW_FUNC(codec, reg_raw_write(codec, reg, val));
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_write_raw);

static int reg_raw_read(struct hdac_device *codec, unsigned int reg,
                        unsigned int *val, bool uncached)
{
        guard(mutex)(&codec->regmap_lock);
        if (uncached || !codec->regmap)
                return hda_reg_read(codec, reg, val);
        else
                return regmap_read(codec->regmap, reg, val);
}

static int __snd_hdac_regmap_read_raw(struct hdac_device *codec,
                                      unsigned int reg, unsigned int *val,
                                      bool uncached)
{
        return CALL_RAW_FUNC(codec, reg_raw_read(codec, reg, val, uncached));
}

/**
 * snd_hdac_regmap_read_raw - read a pseudo register with power mgmt
 * @codec: the codec object
 * @reg: pseudo register
 * @val: pointer to store the read value
 *
 * Returns zero if successful or a negative error code.
 */
int snd_hdac_regmap_read_raw(struct hdac_device *codec, unsigned int reg,
                             unsigned int *val)
{
        return __snd_hdac_regmap_read_raw(codec, reg, val, false);
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_read_raw);

/* Works like snd_hdac_regmap_read_raw(), but this doesn't read from the
 * cache but always via hda verbs.
 */
int snd_hdac_regmap_read_raw_uncached(struct hdac_device *codec,
                                      unsigned int reg, unsigned int *val)
{
        return __snd_hdac_regmap_read_raw(codec, reg, val, true);
}

static int reg_raw_update(struct hdac_device *codec, unsigned int reg,
                          unsigned int mask, unsigned int val)
{
        unsigned int orig;
        bool change;
        int err;

        guard(mutex)(&codec->regmap_lock);
        if (codec->regmap) {
                err = regmap_update_bits_check(codec->regmap, reg, mask, val,
                                               &change);
                if (!err)
                        err = change ? 1 : 0;
        } else {
                err = hda_reg_read(codec, reg, &orig);
                if (!err) {
                        val &= mask;
                        val |= orig & ~mask;
                        if (val != orig) {
                                err = hda_reg_write(codec, reg, val);
                                if (!err)
                                        err = 1;
                        }
                }
        }
        return err;
}

/**
 * snd_hdac_regmap_update_raw - update a pseudo register with power mgmt
 * @codec: the codec object
 * @reg: pseudo register
 * @mask: bit mask to update
 * @val: value to update
 *
 * Returns zero if successful or a negative error code.
 */
int snd_hdac_regmap_update_raw(struct hdac_device *codec, unsigned int reg,
                               unsigned int mask, unsigned int val)
{
        return CALL_RAW_FUNC(codec, reg_raw_update(codec, reg, mask, val));
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_update_raw);

static int reg_raw_update_once(struct hdac_device *codec, unsigned int reg,
                               unsigned int mask, unsigned int val)
{
        if (!codec->regmap)
                return reg_raw_update(codec, reg, mask, val);

        guard(mutex)(&codec->regmap_lock);
        /* Discard any updates to already initialised registers. */
        if (!regcache_reg_cached(codec->regmap, reg))
                return regmap_update_bits(codec->regmap, reg, mask, val);
        return 0;
}

/**
 * snd_hdac_regmap_update_raw_once - initialize the register value only once
 * @codec: the codec object
 * @reg: pseudo register
 * @mask: bit mask to update
 * @val: value to update
 *
 * Performs the update of the register bits only once when the register
 * hasn't been initialized yet.  Used in HD-audio legacy driver.
 * Returns zero if successful or a negative error code
 */
int snd_hdac_regmap_update_raw_once(struct hdac_device *codec, unsigned int reg,
                                    unsigned int mask, unsigned int val)
{
        return CALL_RAW_FUNC(codec, reg_raw_update_once(codec, reg, mask, val));
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_update_raw_once);

/**
 * snd_hdac_regmap_sync - sync out the cached values for PM resume
 * @codec: the codec object
 */
void snd_hdac_regmap_sync(struct hdac_device *codec)
{
        guard(mutex)(&codec->regmap_lock);
        if (codec->regmap)
                regcache_sync(codec->regmap);
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_sync);