max2820.c

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/*
 * Radio tuning for Maxim max2820 on RTL8180
 *
 * Copyright 2007 Andrea Merello <[email protected]>
 *
 * 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!
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#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->channel->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,
};