// SPDX-License-Identifier: GPL-2.0-only
/*
 * Radio tuning for Maxim max2820 on RTL8180
 *
 * Copyright 2007 Andrea Merello <andrea.merello@gmail.com>
 *
 * Code from the BSD driver and the rtl8181 project have been
 * very useful to understand certain things
 *
 * I want to thanks the Authors of such projects and the Ndiswrapper
 * project Authors.
 *
 * A special Big Thanks also is for all people who donated me cards,
 * making possible the creation of the original rtl8180 driver
 * from which this code is derived!
 */

#include <linux/pci.h>
#include <linux/delay.h>
#include <net/mac80211.h>

#include "rtl8180.h"
#include "max2820.h"

static const u32 max2820_chan[] = {
        12, /* CH 1 */
        17,
        22,
        27,
        32,
        37,
        42,
        47,
        52,
        57,
        62,
        67,
        72,
        84, /* CH 14 */
};

static void write_max2820(struct ieee80211_hw *dev, u8 addr, u32 data)
{
        struct rtl8180_priv *priv = dev->priv;
        u32 phy_config;

        phy_config = 0x90 + (data & 0xf);
        phy_config <<= 16;
        phy_config += addr;
        phy_config <<= 8;
        phy_config += (data >> 4) & 0xff;

        rtl818x_iowrite32(priv,
                (__le32 __iomem *) &priv->map->RFPinsOutput, phy_config);

        msleep(1);
}

static void max2820_write_phy_antenna(struct ieee80211_hw *dev, short chan)
{
        struct rtl8180_priv *priv = dev->priv;
        u8 ant;

        ant = MAXIM_ANTENNA;
        if (priv->rfparam & RF_PARAM_ANTBDEFAULT)
                ant |= BB_ANTENNA_B;
        if (chan == 14)
                ant |= BB_ANTATTEN_CHAN14;

        rtl8180_write_phy(dev, 0x10, ant);
}

static u8 max2820_rf_calc_rssi(u8 agc, u8 sq)
{
        bool odd;

        odd = !!(agc & 1);

        agc >>= 1;
        if (odd)
                agc += 76;
        else
                agc += 66;

        /* TODO: change addends above to avoid mult / div below */
        return 65 * agc / 100;
}

static void max2820_rf_set_channel(struct ieee80211_hw *dev,
                                   struct ieee80211_conf *conf)
{
        struct rtl8180_priv *priv = dev->priv;
        int channel = conf ?
                ieee80211_frequency_to_channel(conf->chandef.chan->center_freq) : 1;
        unsigned int chan_idx = channel - 1;
        u32 txpw = priv->channels[chan_idx].hw_value & 0xFF;
        u32 chan = max2820_chan[chan_idx];

        /* While philips SA2400 drive the PA bias from
         * sa2400, for MAXIM we do this directly from BB */
        rtl8180_write_phy(dev, 3, txpw);

        max2820_write_phy_antenna(dev, channel);
        write_max2820(dev, 3, chan);
}

static void max2820_rf_stop(struct ieee80211_hw *dev)
{
        rtl8180_write_phy(dev, 3, 0x8);
        write_max2820(dev, 1, 0);
}


static void max2820_rf_init(struct ieee80211_hw *dev)
{
        struct rtl8180_priv *priv = dev->priv;

        /* MAXIM from netbsd driver */
        write_max2820(dev, 0, 0x007); /* test mode as indicated in datasheet */
        write_max2820(dev, 1, 0x01e); /* enable register */
        write_max2820(dev, 2, 0x001); /* synt register */

        max2820_rf_set_channel(dev, NULL);

        write_max2820(dev, 4, 0x313); /* rx register */

        /* PA is driven directly by the BB, we keep the MAXIM bias
         * at the highest value in case that setting it to lower
         * values may introduce some further attenuation somewhere..
         */
        write_max2820(dev, 5, 0x00f);

        /* baseband configuration */
        rtl8180_write_phy(dev, 0, 0x88); /* sys1       */
        rtl8180_write_phy(dev, 3, 0x08); /* txagc      */
        rtl8180_write_phy(dev, 4, 0xf8); /* lnadet     */
        rtl8180_write_phy(dev, 5, 0x90); /* ifagcinit  */
        rtl8180_write_phy(dev, 6, 0x1a); /* ifagclimit */
        rtl8180_write_phy(dev, 7, 0x64); /* ifagcdet   */

        max2820_write_phy_antenna(dev, 1);

        rtl8180_write_phy(dev, 0x11, 0x88); /* trl */

        if (rtl818x_ioread8(priv, &priv->map->CONFIG2) &
            RTL818X_CONFIG2_ANTENNA_DIV)
                rtl8180_write_phy(dev, 0x12, 0xc7);
        else
                rtl8180_write_phy(dev, 0x12, 0x47);

        rtl8180_write_phy(dev, 0x13, 0x9b);

        rtl8180_write_phy(dev, 0x19, 0x0);  /* CHESTLIM */
        rtl8180_write_phy(dev, 0x1a, 0x9f); /* CHSQLIM  */

        max2820_rf_set_channel(dev, NULL);
}

const struct rtl818x_rf_ops max2820_rf_ops = {
        .name           = "Maxim",
        .init           = max2820_rf_init,
        .stop           = max2820_rf_stop,
        .set_chan       = max2820_rf_set_channel,
        .calc_rssi      = max2820_rf_calc_rssi,
};