rockbox/firmware/drivers/axp-pmu.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2021 Aidan MacDonald
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include "axp-pmu.h"
#include "power.h"
#include "system.h"
#include "i2c-async.h"
#include <string.h>

/* Headers for the debug menu */
#ifndef BOOTLOADER
# include "action.h"
# include "list.h"
# include <stdio.h>
#endif

struct axp_adc_info {
    uint8_t reg;
    uint8_t en_reg;
    uint8_t en_bit;
    int8_t num;
    int8_t den;
};

struct axp_supply_info {
    uint8_t volt_reg;
    uint8_t volt_reg_mask;
    uint8_t en_reg;
    uint8_t en_bit;
    int min_mV;
    int max_mV;
    int step_mV;
};

static const struct axp_adc_info axp_adc_info[NUM_ADC_CHANNELS] = {
    [ADC_ACIN_VOLTAGE]      = {0x56, AXP_REG_ADCENABLE1, 1 << 5, 17, 10},
    [ADC_ACIN_CURRENT]      = {0x58, AXP_REG_ADCENABLE1, 1 << 4,  5,  8},
    [ADC_VBUS_VOLTAGE]      = {0x5a, AXP_REG_ADCENABLE1, 1 << 3, 17, 10},
    [ADC_VBUS_CURRENT]      = {0x5c, AXP_REG_ADCENABLE1, 1 << 2,  3,  8},
    [ADC_INTERNAL_TEMP]     = {0x5e, AXP_REG_ADCENABLE2, 1 << 7,  0,  0},
    [ADC_TS_INPUT]          = {0x62, AXP_REG_ADCENABLE1, 1 << 1,  4,  5},
    [ADC_BATTERY_VOLTAGE]   = {0x78, AXP_REG_ADCENABLE1, 1 << 7, 11, 10},
    [ADC_CHARGE_CURRENT]    = {0x7a, AXP_REG_ADCENABLE1, 1 << 6,  1,  2},
    [ADC_DISCHARGE_CURRENT] = {0x7c, AXP_REG_ADCENABLE1, 1 << 6,  1,  2},
    [ADC_APS_VOLTAGE]       = {0x7e, AXP_REG_ADCENABLE1, 1 << 1,  7,  5},
};

static const struct axp_supply_info axp_supply_info[AXP_NUM_SUPPLIES] = {
#if HAVE_AXP_PMU == 192
    [AXP_SUPPLY_DCDC1] = {
        .volt_reg = 0x26,
        .volt_reg_mask = 0x7f,
        .en_reg = 0x12,
        .en_bit = 0,
        .min_mV = 700,
        .max_mV = 3500,
        .step_mV = 25,
    },
    [AXP_SUPPLY_DCDC2] = {
        .volt_reg = 0x23,
        .volt_reg_mask = 0x3f,
        .en_reg = 0x10,
        .en_bit = 0,
        .min_mV = 700,
        .max_mV = 2275,
        .step_mV = 25,
    },
    [AXP_SUPPLY_DCDC3] = {
        .volt_reg = 0x27,
        .volt_reg_mask = 0x7f,
        .en_reg = 0x12,
        .en_bit = 1,
        .min_mV = 700,
        .max_mV = 3500,
        .step_mV = 25,
    },
    /*
     * NOTE: LDO1 is always on, and we can't query it or change voltages
     */
    [AXP_SUPPLY_LDO2] = {
        .volt_reg = 0x28,
        .volt_reg_mask = 0xf0,
        .en_reg = 0x12,
        .en_bit = 2,
        .min_mV = 1800,
        .max_mV = 3300,
        .step_mV = 100,
    },
    [AXP_SUPPLY_LDO3] = {
        .volt_reg = 0x28,
        .volt_reg_mask = 0x0f,
        .en_reg = 0x12,
        .en_bit = 3,
        .min_mV = 1800,
        .max_mV = 3300,
        .step_mV = 100,
    },
    [AXP_SUPPLY_LDO_IO0] = {
        .volt_reg = 0x91,
        .volt_reg_mask = 0xf0,
        .en_reg = 0x90,
        .en_bit = 0xff, /* this one requires special handling */
        .min_mV = 1800,
        .max_mV = 3300,
        .step_mV = 100,
    },
#else
# error "Untested AXP chip"
#endif
};

void axp_init(void)
{
}

void axp_supply_set_voltage(int supply, int voltage)
{
    const struct axp_supply_info* info = &axp_supply_info[supply];
    if(info->volt_reg == 0 || info->volt_reg_mask == 0)
        return;

    if(voltage > 0 && info->step_mV != 0) {
        if(voltage < info->min_mV || voltage > info->max_mV)
            return;

        int regval = (voltage - info->min_mV) / info->step_mV;
        i2c_reg_modify1(AXP_PMU_BUS, AXP_PMU_ADDR, info->volt_reg,
                        info->volt_reg_mask, regval, NULL);
    }

    if(info->en_bit != 0xff) {
        i2c_reg_setbit1(AXP_PMU_BUS, AXP_PMU_ADDR,
                        info->en_reg, info->en_bit,
                        voltage > 0 ? 1 : 0, NULL);
    }
}

int axp_supply_get_voltage(int supply)
{
    const struct axp_supply_info* info = &axp_supply_info[supply];
    if(info->volt_reg == 0)
        return AXP_SUPPLY_NOT_PRESENT;

    if(info->en_reg != 0) {
        int r = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, info->en_reg);
        if(r < 0)
            return AXP_SUPPLY_DISABLED;

#if HAVE_AXP_PMU == 192
        if(supply == AXP_SUPPLY_LDO_IO0) {
            if((r & 7) != 2)
                return AXP_SUPPLY_DISABLED;
        } else
#endif
        {
            if(r & (1 << info->en_bit) == 0)
                return AXP_SUPPLY_DISABLED;
        }
    }

    /* Hack, avoid undefined shift below. Can be useful too... */
    if(info->volt_reg_mask == 0)
        return info->min_mV;

    int r = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, info->volt_reg);
    if(r < 0)
        return 0;

    int bit = find_first_set_bit(info->volt_reg_mask);
    int val = (r & info->volt_reg_mask) >> bit;
    return info->min_mV + (val * info->step_mV);
}

/* TODO: this can STILL indicate some false positives! */
int axp_battery_status(void)
{
    int r = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_POWERSTATUS);
    if(r >= 0) {
        /* Charging bit indicates we're currently charging */
        if((r & 0x04) != 0)
            return AXP_BATT_CHARGING;

        /* Not plugged in means we're discharging */
        if((r & 0xf0) == 0)
            return AXP_BATT_DISCHARGING;
    } else {
        /* Report discharging if we can't find out power status */
        return AXP_BATT_DISCHARGING;
    }

    /* If the battery is full and not in use, the charging bit will be 0,
     * there will be an external power source, AND the discharge current
     * will be zero. Seems to rule out all false positives. */
    int d = axp_adc_read_raw(ADC_DISCHARGE_CURRENT);
    if(d == 0)
        return AXP_BATT_FULL;

    return AXP_BATT_DISCHARGING;
}

int axp_input_status(void)
{
#ifdef HAVE_BATTERY_SWITCH
    int input_status = 0;
#else
    int input_status = AXP_INPUT_BATTERY;
#endif

    int r = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_POWERSTATUS);
    if(r < 0)
        return input_status;

    /* Check for AC input */
    if(r & 0x80)
        input_status |= AXP_INPUT_AC;

    /* Only report USB if ACIN and VBUS are not shorted */
    if((r & 0x20) != 0 && (r & 0x02) == 0)
        input_status |= AXP_INPUT_USB;

#ifdef HAVE_BATTERY_SWITCH
    /* Check for battery presence if target defines it as removable */
    r = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_CHARGESTATUS);
    if(r >= 0 && (r & 0x20) != 0)
        input_status |= AXP_INPUT_BATTERY;
#endif

    return input_status;
}

int axp_adc_read(int adc)
{
    int value = axp_adc_read_raw(adc);
    if(value == INT_MIN)
        return INT_MIN;

    return axp_adc_conv_raw(adc, value);
}

int axp_adc_read_raw(int adc)
{
    /* Read the ADC */
    uint8_t buf[2];
    uint8_t reg = axp_adc_info[adc].reg;
    int rc = i2c_reg_read(AXP_PMU_BUS, AXP_PMU_ADDR, reg, 2, &buf[0]);
    if(rc != I2C_STATUS_OK)
        return INT_MIN;

    /* Parse the value */
    if(adc == ADC_CHARGE_CURRENT || adc == ADC_DISCHARGE_CURRENT)
        return (buf[0] << 5) | (buf[1] & 0x1f);
    else
        return (buf[0] << 4) | (buf[1] & 0xf);
}

int axp_adc_conv_raw(int adc, int value)
{
    if(adc == ADC_INTERNAL_TEMP)
        return value - 1447;
    else
        return axp_adc_info[adc].num * value / axp_adc_info[adc].den;
}

void axp_adc_set_enabled(int adc_bits)
{
    uint8_t xfer[3];
    xfer[0] = 0;
    xfer[1] = AXP_REG_ADCENABLE2;
    xfer[2] = 0;

    /* Compute the new register values */
    const struct axp_adc_info* info = axp_adc_info;
    for(int i = 0; i < NUM_ADC_CHANNELS; ++i) {
        if(!(adc_bits & (1 << i)))
            continue;

        if(info[i].en_reg == AXP_REG_ADCENABLE1)
            xfer[0] |= info[i].en_bit;
        else
            xfer[2] |= info[i].en_bit;
    }

    /* Update the configuration */
    i2c_reg_write(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_ADCENABLE1, 3, &xfer[0]);
}

int axp_adc_get_rate(void)
{
    int r = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_ADCSAMPLERATE);
    if(r < 0)
        return AXP_ADC_RATE_100HZ; /* an arbitrary value */

    return (r >> 6) & 3;
}

void axp_adc_set_rate(int rate)
{
    i2c_reg_modify1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_ADCSAMPLERATE,
                    0xc0, (rate & 3) << 6, NULL);
}

static uint32_t axp_cc_parse(const uint8_t* buf)
{
    return ((uint32_t)buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
}

void axp_cc_read(uint32_t* charge, uint32_t* discharge)
{
    uint8_t buf[8];
    int rc = i2c_reg_read(AXP_PMU_BUS, AXP_PMU_ADDR,
                          AXP_REG_COULOMBCOUNTERBASE, 8, &buf[0]);
    if(rc != I2C_STATUS_OK) {
        if(charge)
            *charge = 0;
        if(discharge)
            *discharge = 0;
        return;
    }

    if(charge)
        *charge = axp_cc_parse(&buf[0]);
    if(discharge)
        *discharge = axp_cc_parse(&buf[4]);
}

void axp_cc_clear(void)
{
    i2c_reg_setbit1(AXP_PMU_BUS, AXP_PMU_ADDR,
                    AXP_REG_COULOMBCOUNTERCTRL, 5, 1, NULL);
}

void axp_cc_enable(bool en)
{
    i2c_reg_setbit1(AXP_PMU_BUS, AXP_PMU_ADDR,
                    AXP_REG_COULOMBCOUNTERCTRL, 7, en ? 1 : 0, NULL);
}

bool axp_cc_is_enabled(void)
{
    int reg = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR,
                            AXP_REG_COULOMBCOUNTERCTRL);
    return reg >= 0 && (reg & 0x40) != 0;
}

static const int chargecurrent_tbl[] = {
    100,  190,  280,  360,
    450,  550,  630,  700,
    780,  880,  960,  1000,
    1080, 1160, 1240, 1320,
};

void axp_set_charge_current(int current_mA)
{
    /* find greatest charging current not exceeding requested current */
    unsigned int index = 0;
    while(index < ARRAYLEN(chargecurrent_tbl)-1 &&
          chargecurrent_tbl[index+1] <= current_mA)
        ++index;

    i2c_reg_modify1(AXP_PMU_BUS, AXP_PMU_ADDR,
                    AXP_REG_CHARGECONTROL1, 0x0f, index, NULL);
}

int axp_get_charge_current(void)
{
    int ret = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR,
                            AXP_REG_CHARGECONTROL1);
    if(ret < 0)
        ret = 0;

    return chargecurrent_tbl[ret & 0x0f];
}

void axp_power_off(void)
{
    /* Set the shutdown bit */
    i2c_reg_setbit1(AXP_PMU_BUS, AXP_PMU_ADDR,
                    AXP_REG_SHUTDOWNLEDCTRL, 7, 1, NULL);
}

#ifndef BOOTLOADER
enum {
    AXP_DEBUG_BATTERY_STATUS,
    AXP_DEBUG_INPUT_STATUS,
    AXP_DEBUG_CHARGE_CURRENT,
    AXP_DEBUG_COULOMB_COUNTERS,
    AXP_DEBUG_ADC_RATE,
    AXP_DEBUG_FIRST_ADC,
    AXP_DEBUG_FIRST_SUPPLY = AXP_DEBUG_FIRST_ADC + NUM_ADC_CHANNELS,
    AXP_DEBUG_NUM_ENTRIES = AXP_DEBUG_FIRST_SUPPLY + AXP_NUM_SUPPLIES,
};

static int axp_debug_menu_cb(int action, struct gui_synclist* lists)
{
    (void)lists;

    if(action == ACTION_NONE)
        action = ACTION_REDRAW;

    return action;
}

static const char* axp_debug_menu_get_name(int item, void* data,
                                           char* buf, size_t buflen)
{
    (void)data;

    static const char* const adc_names[] = {
        "V_acin", "I_acin", "V_vbus", "I_vbus", "T_int",
        "V_ts", "V_batt", "I_chrg", "I_dchg", "V_aps", "P_batt"
    };

    static const char* const adc_units[] = {
        "mV", "mA", "mV", "mA", "C", "mV", "mV", "mA", "mA", "mV", "uW",
    };

    static const char* const supply_names[] = {
        "DCDC1", "DCDC2", "DCDC3",
        "LDO1", "LDO2", "LDO3", "LDO_IO0",
    };

    int adc = item - AXP_DEBUG_FIRST_ADC;
    if(item >= AXP_DEBUG_FIRST_ADC && adc < NUM_ADC_CHANNELS) {
        int raw_value = axp_adc_read_raw(adc);
        if(raw_value == INT_MIN) {
            snprintf(buf, buflen, "%s: [Disabled]", adc_names[adc]);
            return buf;
        }

        int value = axp_adc_conv_raw(adc, raw_value);
        if(adc == ADC_INTERNAL_TEMP) {
            snprintf(buf, buflen, "%s: %d.%d %s", adc_names[adc],
                     value/10, value%10, adc_units[adc]);
        } else {
            snprintf(buf, buflen, "%s: %d %s", adc_names[adc],
                     value, adc_units[adc]);
        }

        return buf;
    }

    int supply = item - AXP_DEBUG_FIRST_SUPPLY;
    if(item >= AXP_DEBUG_FIRST_SUPPLY && supply < AXP_NUM_SUPPLIES) {
        int voltage = axp_supply_get_voltage(supply);
        if(voltage == AXP_SUPPLY_NOT_PRESENT)
            snprintf(buf, buflen, "%s: [Not Present]", supply_names[supply]);
        else if(voltage == AXP_SUPPLY_DISABLED)
            snprintf(buf, buflen, "%s: [Disabled]", supply_names[supply]);
        else
            snprintf(buf, buflen, "%s: %d mV", supply_names[supply], voltage);

        return buf;
    }

    switch(item) {
    case AXP_DEBUG_BATTERY_STATUS: {
        switch(axp_battery_status()) {
        case AXP_BATT_FULL:
            return "Battery: Full";
        case AXP_BATT_CHARGING:
            return "Battery: Charging";
        case AXP_BATT_DISCHARGING:
            return "Battery: Discharging";
        default:
            return "Battery: Unknown";
        }
    } break;

    case AXP_DEBUG_INPUT_STATUS: {
        int s = axp_input_status();
        const char* ac = (s & AXP_INPUT_AC) ? " AC" : "";
        const char* usb = (s & AXP_INPUT_USB) ? " USB" : "";
        const char* batt = (s & AXP_INPUT_BATTERY) ? " Battery" : "";
        snprintf(buf, buflen, "Inputs:%s%s%s", ac, usb, batt);
        return buf;
    } break;

    case AXP_DEBUG_CHARGE_CURRENT: {
        int current = axp_get_charge_current();
        snprintf(buf, buflen, "Max charge current: %d mA", current);
        return buf;
    } break;

    case AXP_DEBUG_COULOMB_COUNTERS: {
        uint32_t charge, discharge;
        axp_cc_read(&charge, &discharge);

        snprintf(buf, buflen, "Coulomb counters: +%lu / -%lu",
                 (unsigned long)charge, (unsigned long)discharge);
        return buf;
    } break;

    case AXP_DEBUG_ADC_RATE: {
        int rate = 25 << axp_adc_get_rate();
        snprintf(buf, buflen, "ADC sample rate: %d Hz", rate);
        return buf;
    } break;

    default:
        return "---";
    }
}

bool axp_debug_menu(void)
{
    struct simplelist_info info;
    simplelist_info_init(&info, "AXP debug", AXP_DEBUG_NUM_ENTRIES, NULL);
    info.action_callback = axp_debug_menu_cb;
    info.get_name = axp_debug_menu_get_name;
    return simplelist_show_list(&info);
}
#endif /* !BOOTLOADER */

/* This is basically the only valid implementation, so define it here */
unsigned int power_input_status(void)
{
    unsigned int state = 0;
    int input_status = axp_input_status();

    if(input_status & AXP_INPUT_AC)
        state |= POWER_INPUT_MAIN_CHARGER;

    if(input_status & AXP_INPUT_USB)
        state |= POWER_INPUT_USB_CHARGER;

#ifdef HAVE_BATTERY_SWITCH
    if(input_status & AXP_INPUT_BATTERY)
        state |= POWER_INPUT_BATTERY;
#endif

    return state;
}