Revert "AXP PMU rewrite (again)"

This caused LCD problems on the ErosQ, where the screen would
go white until being put through a sleep/wake cycle. The exact
reason for this isn't obvious, but the problem didn't exist
prior to the AXP driver rewrite.

The two dependent changes,

42999913ba - x1000: Increase USB current limit to 500 mA at all times
90dd2f84a9 - x1000: Correctly limit USB charging current

ended up bringing the USB charging situation back to where it
was prior to the rewrite, so the cleanest option is to revert
the whole lot.

This reverts commit 42999913ba3a76221fceb04b1f935ed4e0e71476.
This reverts commit 90dd2f84a9174c38dbfb07d582ec6ee7697b1939.
This reverts commit 2d891439623bb76d38b98202ca5f3eea3c01c5f0.

Change-Id: I1cff2bfdd1b189df14bcf8cce42db725caa470d7

1 files changed, 670 insertions, 0 deletions

diff --git a/firmware/drivers/axp-pmu.c b/firmware/drivers/axp-pmu.c
new file mode 100644
index 0000000000..fd1126dbbf
--- /dev/null
+++ b/firmware/drivers/axp-pmu.c
@@ -0,0 +1,670 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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;
+};
+
+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] = {
+    {0x56, AXP_REG_ADCENABLE1, 5}, /* ACIN_VOLTAGE */
+    {0x58, AXP_REG_ADCENABLE1, 4}, /* ACIN_CURRENT */
+    {0x5a, AXP_REG_ADCENABLE1, 3}, /* VBUS_VOLTAGE */
+    {0x5c, AXP_REG_ADCENABLE1, 2}, /* VBUS_CURRENT */
+    {0x5e, AXP_REG_ADCENABLE2, 7}, /* INTERNAL_TEMP */
+    {0x62, AXP_REG_ADCENABLE1, 1}, /* TS_INPUT */
+    {0x78, AXP_REG_ADCENABLE1, 7}, /* BATTERY_VOLTAGE */
+    {0x7a, AXP_REG_ADCENABLE1, 6}, /* CHARGE_CURRENT */
+    {0x7c, AXP_REG_ADCENABLE1, 6}, /* DISCHARGE_CURRENT */
+    {0x7e, AXP_REG_ADCENABLE1, 1}, /* APS_VOLTAGE */
+    {0x70, 0xff, 0},               /* BATTERY_POWER */
+};
+
+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
+};
+
+static struct axp_driver {
+    int adc_enable;
+    int chargecurrent_setting;
+    int chip_id;
+} axp;
+
+static void axp_init_enabled_adcs(void)
+{
+    axp.adc_enable = 0;
+
+    /* Read chip ID, so we can display it on the debug screen.
+     * This is undocumented but there's Linux driver code floating around
+     * which suggests this should work for many AXP chips. */
+    axp.chip_id = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_CHIP_ID);
+
+    /* Read enabled ADCs from the hardware */
+    uint8_t regs[2];
+    int rc = i2c_reg_read(AXP_PMU_BUS, AXP_PMU_ADDR,
+                          AXP_REG_ADCENABLE1, 2, &regs[0]);
+    if(rc != I2C_STATUS_OK)
+        return;
+
+    /* Parse registers to set ADC enable bits */
+    const struct axp_adc_info* info = axp_adc_info;
+    for(int i = 0; i < NUM_ADC_CHANNELS; ++i) {
+        if(info[i].en_reg == 0xff)
+            continue;
+
+        if(regs[info[i].en_reg - AXP_REG_ADCENABLE1] & info[i].en_bit)
+            axp.adc_enable |= 1 << i;
+    }
+
+    /* Handle battery power ADC */
+    if((axp.adc_enable & (1 << ADC_BATTERY_VOLTAGE)) &&
+       (axp.adc_enable & (1 << ADC_DISCHARGE_CURRENT))) {
+        axp.adc_enable |= (1 << ADC_BATTERY_POWER);
+    }
+}
+
+void axp_init(void)
+{
+    axp_init_enabled_adcs();
+
+    /* We need discharge current ADC to reliably poll for a full battery */
+    int bits = axp.adc_enable;
+    bits |= (1 << ADC_DISCHARGE_CURRENT);
+    axp_adc_set_enabled(bits);
+
+    /* Read the maximum charging current */
+    int value = i2c_reg_read1(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_CHARGECONTROL1);
+    axp.chargecurrent_setting = (value < 0) ? -1 : (value & 0xf);
+}
+
+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)
+{
+    /* Don't give a reading if the ADC is not enabled */
+    if((axp.adc_enable & (1 << adc)) == 0)
+        return INT_MIN;
+
+    /* Read the ADC */
+    uint8_t buf[3];
+    int count = (adc == ADC_BATTERY_POWER) ? 3 : 2;
+    uint8_t reg = axp_adc_info[adc].reg;
+    int rc = i2c_reg_read(AXP_PMU_BUS, AXP_PMU_ADDR, reg, count, &buf[0]);
+    if(rc != I2C_STATUS_OK)
+        return INT_MIN;
+
+    /* Parse the value */
+    if(adc == ADC_BATTERY_POWER)
+        return (buf[0] << 16) | (buf[1] << 8) | buf[2];
+    else 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)
+{
+    switch(adc) {
+    case ADC_ACIN_VOLTAGE:
+    case ADC_VBUS_VOLTAGE:
+        /* 0 mV ... 6.9615 mV, step 1.7 mV */
+        return value * 17 / 10;
+    case ADC_ACIN_CURRENT:
+        /* 0 mA ... 2.5594 A, step 0.625 mA */
+        return value * 5 / 8;
+    case ADC_VBUS_CURRENT:
+        /* 0 mA ... 1.5356 A, step 0.375 mA */
+        return value * 3 / 8;
+    case ADC_INTERNAL_TEMP:
+        /* -144.7 C ... 264.8 C, step 0.1 C */
+        return value - 1447;
+    case ADC_TS_INPUT:
+        /* 0 mV ... 3.276 V, step 0.8 mV */
+        return value * 4 / 5;
+    case ADC_BATTERY_VOLTAGE:
+        /* 0 mV ... 4.5045 V, step 1.1 mV */
+        return value * 11 / 10;
+    case ADC_CHARGE_CURRENT:
+    case ADC_DISCHARGE_CURRENT:
+        /* 0 mA to 4.095 A, step 0.5 mA */
+        return value / 2;
+    case ADC_APS_VOLTAGE:
+        /* 0 mV to 5.733 V, step 1.4 mV */
+        return value * 7 / 5;
+    case ADC_BATTERY_POWER:
+        /* 0 uW to 23.6404 W, step 0.55 uW */
+        return value * 11 / 20;
+    default:
+        /* Shouldn't happen */
+        return INT_MIN;
+    }
+}
+
+int axp_adc_get_enabled(void)
+{
+    return axp.adc_enable;
+}
+
+void axp_adc_set_enabled(int adc_bits)
+{
+    /* Ignore no-op */
+    if(adc_bits == axp.adc_enable)
+        return;
+
+    /* Compute the new register values */
+    const struct axp_adc_info* info = axp_adc_info;
+    uint8_t regs[2] = {0, 0};
+    for(int i = 0; i < NUM_ADC_CHANNELS; ++i) {
+        if(info[i].en_reg == 0xff)
+            continue;
+
+        if(adc_bits & (1 << i))
+            regs[info[i].en_reg - 0x82] |= 1 << info[i].en_bit;
+    }
+
+    /* These ADCs share an enable bit */
+    if(adc_bits & ((1 << ADC_CHARGE_CURRENT)|(1 << ADC_DISCHARGE_CURRENT))) {
+        adc_bits |= (1 << ADC_CHARGE_CURRENT);
+        adc_bits |= (1 << ADC_DISCHARGE_CURRENT);
+    }
+
+    /* Enable required bits for battery power ADC */
+    if(adc_bits & (1 << ADC_BATTERY_POWER)) {
+        regs[0] |= 1 << info[ADC_DISCHARGE_CURRENT].en_bit;
+        regs[0] |= 1 << info[ADC_BATTERY_VOLTAGE].en_bit;
+    }
+
+    /* Update the configuration */
+    i2c_reg_write(AXP_PMU_BUS, AXP_PMU_ADDR, AXP_REG_ADCENABLE1, 2, &regs[0]);
+    axp.adc_enable = adc_bits;
+}
+
+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,
+};
+
+static const int chargecurrent_tblsz = sizeof(chargecurrent_tbl)/sizeof(int);
+
+void axp_set_charge_current(int maxcurrent)
+{
+    /* Find the charge current just higher than maxcurrent */
+    int value = 0;
+    while(value < chargecurrent_tblsz &&
+          chargecurrent_tbl[value] <= maxcurrent)
+        ++value;
+
+    /* Select the next lower current, the greatest current <= maxcurrent */
+    if(value >= chargecurrent_tblsz)
+        value = chargecurrent_tblsz - 1;
+    else if(value > 0)
+        --value;
+
+    /* Don't issue i2c write if desired setting is already in use */
+    if(value == axp.chargecurrent_setting)
+        return;
+
+    /* Update register */
+    i2c_reg_modify1(AXP_PMU_BUS, AXP_PMU_ADDR,
+                    AXP_REG_CHARGECONTROL1, 0x0f, value, NULL);
+    axp.chargecurrent_setting = value;
+}
+
+int axp_get_charge_current(void)
+{
+    if(axp.chargecurrent_setting < 0)
+        return chargecurrent_tbl[0];
+    else
+        return chargecurrent_tbl[axp.chargecurrent_setting];
+}
+
+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_CHIP_ID,
+    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_CHIP_ID: {
+        snprintf(buf, buflen, "Chip ID: %d (%02x) [Driver: AXP%d]",
+                 axp.chip_id, axp.chip_id, HAVE_AXP_PMU);
+        return buf;
+    } break;
+
+    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;
+}