New port: FiiO M3K on bare metal

Change-Id: I7517e7d5459e129dcfc9465c6fbd708619888fbe

3 files changed, 797 insertions, 0 deletions

diff --git a/firmware/drivers/audio/ak4376.c b/firmware/drivers/audio/ak4376.c
new file mode 100644
index 0000000000..494bbabfa4
--- /dev/null
+++ b/firmware/drivers/audio/ak4376.c
@@ -0,0 +1,274 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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 "audiohw.h"
+#include "sound.h"
+#include "panic.h"
+#include "pcm_sampr.h"
+#include "pcm_sw_volume.h"
+#include "system.h"
+#include "i2c-async.h"
+
+#ifndef HAVE_SW_VOLUME_CONTROL
+# error "AK4376 requires HAVE_SW_VOLUME_CONTROL!"
+#endif
+
+/* NOTE: At present, only the FiiO M3K uses this driver so the handling of
+ * the clock / audio interface is limited to I2S slave, 16-bit samples, with
+ * DAC master clock provided directly on the MCLK input pin, fitting the
+ * clock setup of the M3K.
+ *
+ * Feel free to expand upon this if another target ever needs this driver.
+ */
+
+/* Converts HW_FREQ_XX constants to register values */
+static const int ak4376_fsel_to_hw[] = {
+    HW_HAVE_192_(AK4376_FS_192,)
+    HW_HAVE_176_(AK4376_FS_176,)
+    HW_HAVE_96_(AK4376_FS_96,)
+    HW_HAVE_88_(AK4376_FS_88,)
+    HW_HAVE_64_(AK4376_FS_64,)
+    HW_HAVE_48_(AK4376_FS_48,)
+    HW_HAVE_44_(AK4376_FS_44,)
+    HW_HAVE_32_(AK4376_FS_32,)
+    HW_HAVE_24_(AK4376_FS_24,)
+    HW_HAVE_22_(AK4376_FS_22,)
+    HW_HAVE_16_(AK4376_FS_16,)
+    HW_HAVE_12_(AK4376_FS_12,)
+    HW_HAVE_11_(AK4376_FS_11,)
+    HW_HAVE_8_(AK4376_FS_8,)
+};
+
+static struct ak4376 {
+    int fsel;
+    int low_mode;
+    int regs[AK4376_NUM_REGS];
+} ak4376;
+
+void ak4376_init(void)
+{
+    /* Initialize DAC state */
+    ak4376.fsel = HW_FREQ_48;
+    ak4376.low_mode = 0;
+    for(int i = 0; i < AK4376_NUM_REGS; ++i)
+        ak4376.regs[i] = -1;
+
+    /* Initial reset after power-on */
+    ak4376_set_pdn_pin(0);
+    mdelay(1);
+    ak4376_set_pdn_pin(1);
+    mdelay(1);
+
+    static const int init_config[] = {
+        /* Ensure HPRHZ, HPLHZ are 0 */
+        AK4376_REG_OUTPUT_MODE,  0x00,
+        /* Mute all volume controls */
+        AK4376_REG_MIXER,        0x00,
+        AK4376_REG_LCH_VOLUME,   0x80,
+        AK4376_REG_RCH_VOLUME,   0x00,
+        AK4376_REG_AMP_VOLUME,   0x00,
+        /* Clock source = MCLK, divider = 1 */
+        AK4376_REG_DAC_CLK_SRC,  0x00,
+        AK4376_REG_DAC_CLK_DIV,  0x00,
+        /* I2S slave mode, 16-bit samples */
+        AK4376_REG_AUDIO_IF_FMT, 0x03,
+        /* Recommended by datasheet */
+        AK4376_REG_ADJUST1,      0x20,
+        AK4376_REG_ADJUST2,      0x05,
+        /* Power controls */
+        AK4376_REG_PWR2,         0x33,
+        AK4376_REG_PWR3,         0x01,
+        AK4376_REG_PWR4,         0x03,
+    };
+
+    /* Write initial configuration prior to power-up */
+    for(size_t i = 0; i < ARRAYLEN(init_config); i += 2)
+        ak4376_write(init_config[i], init_config[i+1]);
+
+    /* Initial frequency setting, also handles DAC/amp power-up */
+    audiohw_set_frequency(HW_FREQ_48);
+}
+
+void ak4376_close(void)
+{
+    /* Shut off power */
+    ak4376_write(AK4376_REG_PWR3, 0x00);
+    ak4376_write(AK4376_REG_PWR4, 0x00);
+    ak4376_write(AK4376_REG_PWR2, 0x00);
+
+    /* PDN pin low */
+    ak4376_set_pdn_pin(0);
+}
+
+void ak4376_write(int reg, int value)
+{
+    /* Ensure value is sensible and differs from the last set value */
+    if((value & 0xff) == value && ak4376.regs[reg] != value) {
+        int r = i2c_reg_write1(AK4376_BUS, AK4376_ADDR, reg, value);
+        if(r == I2C_STATUS_OK)
+            ak4376.regs[reg] = value;
+        else
+            ak4376.regs[reg] = -1;
+    }
+}
+
+int ak4376_read(int reg)
+{
+    /* Only read from I2C if we don't already know the value */
+    if(ak4376.regs[reg] < 0)
+        ak4376.regs[reg] = i2c_reg_read1(AK4376_BUS, AK4376_ADDR, reg);
+
+    return ak4376.regs[reg];
+}
+
+static int round_step_up(int x, int step)
+{
+    int rem = x % step;
+    if(rem > 0)
+        rem -= step;
+    return x - rem;
+}
+
+static void calc_volumes(int vol, int* mix, int* dig, int* sw)
+{
+    /* Mixer can divide by 2, which gives an extra -6 dB adjustment */
+    if(vol < AK4376_DIG_VOLUME_MIN) {
+        *mix |= AK4376_MIX_HALF;
+        vol += 60;
+    }
+
+    *dig = round_step_up(vol, AK4376_DIG_VOLUME_STEP);
+    *dig = MIN(*dig, AK4376_DIG_VOLUME_MAX);
+    *dig = MAX(*dig, AK4376_DIG_VOLUME_MIN);
+    vol -= *dig;
+
+    /* Seems that this is the allowable range for software volume */
+    *sw = MIN(vol, 60);
+    *sw = MAX(*sw, -730);
+    vol -= *sw;
+}
+
+static int dig_vol_to_hw(int vol)
+{
+    if(vol < AK4376_DIG_VOLUME_MIN) return 0;
+    if(vol > AK4376_DIG_VOLUME_MAX) return 31;
+    return (vol - AK4376_DIG_VOLUME_MIN) / AK4376_DIG_VOLUME_STEP + 1;
+}
+
+static int amp_vol_to_hw(int vol)
+{
+    if(vol < AK4376_AMP_VOLUME_MIN) return 0;
+    if(vol > AK4376_AMP_VOLUME_MAX) return 14;
+    return (vol - AK4376_AMP_VOLUME_MIN) / AK4376_AMP_VOLUME_STEP + 1;
+}
+
+void audiohw_set_volume(int vol_l, int vol_r)
+{
+    int amp;
+    int mix_l = AK4376_MIX_LCH, dig_l, sw_l;
+    int mix_r = AK4376_MIX_RCH, dig_r, sw_r;
+
+    if(vol_l <= AK4376_MIN_VOLUME && vol_r <= AK4376_MIN_VOLUME) {
+        /* Special case for full mute */
+        amp = AK4376_AMP_VOLUME_MUTE;
+        dig_l = dig_r = AK4376_DIG_VOLUME_MUTE;
+        sw_l = sw_r = PCM_MUTE_LEVEL;
+    } else {
+        /* Amp is a mono control -- calculate based on the loudest channel.
+         * The quieter channel then gets reduced more by digital controls. */
+        amp = round_step_up(MAX(vol_l, vol_r), AK4376_AMP_VOLUME_STEP);
+        amp = MIN(amp, AK4376_AMP_VOLUME_MAX);
+        amp = MAX(amp, AK4376_AMP_VOLUME_MIN);
+
+        /* Other controls are stereo */
+        calc_volumes(vol_l - amp, &mix_l, &dig_l, &sw_l);
+        calc_volumes(vol_r - amp, &mix_r, &dig_r, &sw_r);
+    }
+
+    ak4376_write(AK4376_REG_MIXER, (mix_l & 0xf) | ((mix_r & 0xf) << 4));
+    ak4376_write(AK4376_REG_LCH_VOLUME, dig_vol_to_hw(dig_l) | (1 << 7));
+    ak4376_write(AK4376_REG_RCH_VOLUME, dig_vol_to_hw(dig_r));
+    ak4376_write(AK4376_REG_AMP_VOLUME, amp_vol_to_hw(amp));
+    pcm_set_master_volume(sw_l, sw_r);
+}
+
+void audiohw_set_filter_roll_off(int val)
+{
+    int reg = ak4376_read(AK4376_REG_FILTER);
+    reg &= ~0xc0;
+    reg |= (val & 3) << 6;
+    ak4376_write(AK4376_REG_FILTER, reg);
+}
+
+void audiohw_set_frequency(int fsel)
+{
+    /* Determine master clock multiplier */
+    int mult = ak4376_set_mclk_freq(fsel, false);
+
+    /* Calculate clock mode for frequency. Multipliers of 32/64 are only
+     * for rates >= 256 KHz which are not supported by Rockbox, so they
+     * are commented out -- but they're in the correct place. */
+    int clock_mode = ak4376_fsel_to_hw[fsel];
+    switch(mult) {
+    /* case 32: */
+    case 256:
+        break;
+    /* case 64: */
+    case 512:
+        clock_mode |= 0x20;
+        break;
+    case 1024:
+        clock_mode |= 0x40;
+        break;
+    case 128:
+        clock_mode |= 0x60;
+        break;
+    default:
+        panicf("ak4376: bad master clock multiple %d", mult);
+        return;
+    }
+
+    /* Handle the DSMLP bit in the MODE_CTRL register */
+    int mode_ctrl = 0x00;
+    if(ak4376.low_mode || hw_freq_sampr[fsel] <= SAMPR_12)
+        mode_ctrl |= 0x40;
+
+    /* Program the new settings */
+    ak4376_write(AK4376_REG_CLOCK_MODE, clock_mode);
+    ak4376_write(AK4376_REG_MODE_CTRL, mode_ctrl);
+    ak4376_write(AK4376_REG_PWR3, ak4376.low_mode ? 0x11 : 0x01);
+
+    /* Enable the master clock */
+    ak4376_set_mclk_freq(fsel, true);
+
+    /* Remember the frequency */
+    ak4376.fsel = fsel;
+}
+
+void audiohw_set_power_mode(int mode)
+{
+    /* This is handled via audiohw_set_frequency() since changing LPMODE
+     * bit requires power-down/power-up & changing other bits as well */
+    if(ak4376.low_mode != mode) {
+        ak4376.low_mode = mode;
+        audiohw_set_frequency(ak4376.fsel);
+    }
+}
diff --git a/firmware/drivers/axp173.c b/firmware/drivers/axp173.c
new file mode 100644
index 0000000000..22417650fc
--- /dev/null
+++ b/firmware/drivers/axp173.c
@@ -0,0 +1,419 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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 "axp173.h"
+#include "power.h"
+#include "i2c-async.h"
+
+/* Headers for the debug menu */
+#ifndef BOOTLOADER
+# include "action.h"
+# include "list.h"
+# include <stdio.h>
+#endif
+
+static const struct axp173_adc_info {
+    uint8_t reg;
+    uint8_t en_reg;
+    uint8_t en_bit;
+} axp173_adc_info[NUM_ADC_CHANNELS] = {
+    {0x56, 0x82, 5},    /* ACIN_VOLTAGE */
+    {0x58, 0x82, 4},    /* ACIN_CURRENT */
+    {0x5a, 0x82, 3},    /* VBUS_VOLTAGE */
+    {0x5c, 0x82, 2},    /* VBUS_CURRENT */
+    {0x5e, 0x83, 7},    /* INTERNAL_TEMP */
+    {0x62, 0x82, 1},    /* TS_INPUT */
+    {0x78, 0x82, 7},    /* BATTERY_VOLTAGE */
+    {0x7a, 0x82, 6},    /* CHARGE_CURRENT */
+    {0x7c, 0x82, 6},    /* DISCHARGE_CURRENT */
+    {0x7e, 0x82, 1},    /* APS_VOLTAGE */
+    {0x70, 0xff, 0},    /* BATTERY_POWER */
+};
+
+static struct axp173 {
+    int adc_enable;
+} axp173;
+
+static void axp173_init_enabled_adcs(void)
+{
+    axp173.adc_enable = 0;
+
+    /* Read enabled ADCs from the hardware */
+    uint8_t regs[2];
+    int rc = i2c_reg_read(AXP173_BUS, AXP173_ADDR, 0x82, 2, &regs[0]);
+    if(rc != I2C_STATUS_OK)
+        return;
+
+    /* Parse registers to set ADC enable bits */
+    const struct axp173_adc_info* info = axp173_adc_info;
+    for(int i = 0; i < NUM_ADC_CHANNELS; ++i) {
+        if(info[i].en_reg == 0xff)
+            continue;
+
+        if(regs[info[i].en_reg - 0x82] & info[i].en_bit)
+            axp173.adc_enable |= 1 << i;
+    }
+
+    /* Handle battery power ADC */
+    if((axp173.adc_enable & (1 << ADC_BATTERY_VOLTAGE)) &&
+       (axp173.adc_enable & (1 << ADC_DISCHARGE_CURRENT))) {
+        axp173.adc_enable |= (1 << ADC_BATTERY_POWER);
+    }
+}
+
+void axp173_init(void)
+{
+    axp173_init_enabled_adcs();
+
+    /* We need discharge current ADC to reliably poll for a full battery */
+    int bits = axp173.adc_enable;
+    bits |= (1 << ADC_DISCHARGE_CURRENT);
+    axp173_adc_set_enabled(bits);
+}
+
+/* TODO: this can STILL indicate some false positives! */
+int axp173_battery_status(void)
+{
+    int r = i2c_reg_read1(AXP173_BUS, AXP173_ADDR, 0x00);
+    if(r >= 0) {
+        /* Charging bit indicates we're currently charging */
+        if((r & 0x04) != 0)
+            return AXP173_BATT_CHARGING;
+
+        /* Not plugged in means we're discharging */
+        if((r & 0xf0) == 0)
+            return AXP173_BATT_DISCHARGING;
+    } else {
+        /* Report discharging if we can't find out power status */
+        return AXP173_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 = axp173_adc_read_raw(ADC_DISCHARGE_CURRENT);
+    if(d == 0)
+        return AXP173_BATT_FULL;
+
+    return AXP173_BATT_DISCHARGING;
+}
+
+int axp173_input_status(void)
+{
+#ifdef HAVE_BATTERY_SWITCH
+    int input_status = 0;
+#else
+    int input_status = AXP173_INPUT_BATTERY;
+#endif
+
+    int r = i2c_reg_read1(AXP173_BUS, AXP173_ADDR, 0x00);
+    if(r < 0)
+        return input_status;
+
+    /* Check for AC input */
+    if(r & 0x80)
+        input_status |= AXP173_INPUT_AC;
+
+    /* Only report USB if ACIN and VBUS are not shorted */
+    if((r & 0x20) != 0 && (r & 0x02) == 0)
+        input_status |= AXP173_INPUT_USB;
+
+#ifdef HAVE_BATTERY_SWITCH
+    /* Check for battery presence if target defines it as removable */
+    r = i2c_reg_read1(AXP173_BUS, AXP173_ADDR, 0x01);
+    if(r >= 0 && (r & 0x20) != 0)
+        input_status |= AXP173_INPUT_BATTERY;
+#endif
+
+    return input_status;
+}
+
+int axp173_adc_read(int adc)
+{
+    int value = axp173_adc_read_raw(adc);
+    if(value == INT_MIN)
+        return INT_MIN;
+
+    return axp173_adc_conv_raw(adc, value);
+}
+
+int axp173_adc_read_raw(int adc)
+{
+    /* Don't give a reading if the ADC is not enabled */
+    if((axp173.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 = axp173_adc_info[adc].reg;
+    int rc = i2c_reg_read(AXP173_BUS, AXP173_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 axp173_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 axp173_adc_get_enabled(void)
+{
+    return axp173.adc_enable;
+}
+
+void axp173_adc_set_enabled(int adc_bits)
+{
+    /* Ignore no-op */
+    if(adc_bits == axp173.adc_enable)
+        return;
+
+    /* Compute the new register values */
+    const struct axp173_adc_info* info = axp173_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(AXP173_BUS, AXP173_ADDR, 0x82, 2, &regs[0]);
+    axp173.adc_enable = adc_bits;
+}
+
+int axp173_adc_get_rate(void)
+{
+    int r = i2c_reg_read1(AXP173_BUS, AXP173_ADDR, 0x84);
+    if(r < 0)
+        return AXP173_ADC_RATE_100HZ; /* an arbitrary value */
+
+    return (r >> 6) & 3;
+}
+
+void axp173_adc_set_rate(int rate)
+{
+    i2c_reg_modify1(AXP173_BUS, AXP173_ADDR, 0x84,
+                    0xc0, (rate & 3) << 6, NULL);
+}
+
+static uint32_t axp173_cc_parse(const uint8_t* buf)
+{
+    return ((uint32_t)buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
+}
+
+void axp173_cc_read(uint32_t* charge, uint32_t* discharge)
+{
+    uint8_t buf[8];
+    int rc = i2c_reg_read(AXP173_BUS, AXP173_ADDR, 0xb0, 8, &buf[0]);
+    if(rc != I2C_STATUS_OK) {
+        if(charge)
+            *charge = 0;
+        if(discharge)
+            *discharge = 0;
+        return;
+    }
+
+    if(charge)
+        *charge = axp173_cc_parse(&buf[0]);
+    if(discharge)
+        *discharge = axp173_cc_parse(&buf[4]);
+}
+
+void axp173_cc_clear(void)
+{
+    i2c_reg_setbit1(AXP173_BUS, AXP173_ADDR, 0xb8, 5, 1, NULL);
+}
+
+void axp173_cc_enable(bool en)
+{
+    i2c_reg_setbit1(AXP173_BUS, AXP173_ADDR, 0xb8, 7, en ? 1 : 0, NULL);
+}
+
+#ifndef BOOTLOADER
+#define AXP173_DEBUG_BATTERY_STATUS 0
+#define AXP173_DEBUG_INPUT_STATUS   1
+#define AXP173_DEBUG_ADC_RATE       2
+#define AXP173_DEBUG_FIRST_ADC      3
+#define AXP173_DEBUG_ENTRIES        (AXP173_DEBUG_FIRST_ADC + NUM_ADC_CHANNELS)
+
+static int axp173_debug_menu_cb(int action, struct gui_synclist* lists)
+{
+    (void)lists;
+
+    if(action == ACTION_NONE)
+        action = ACTION_REDRAW;
+
+    return action;
+}
+
+static const char* axp173_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",
+    };
+
+    int adc = item - AXP173_DEBUG_FIRST_ADC;
+    if(item >= AXP173_DEBUG_FIRST_ADC && adc < NUM_ADC_CHANNELS) {
+        int raw_value = axp173_adc_read_raw(adc);
+        if(raw_value == INT_MIN) {
+            snprintf(buf, buflen, "%s: [Disabled]", adc_names[adc]);
+            return buf;
+        }
+
+        int value = axp173_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;
+    }
+
+    switch(item) {
+    case AXP173_DEBUG_BATTERY_STATUS: {
+        switch(axp173_battery_status()) {
+        case AXP173_BATT_FULL:
+            return "Battery: Full";
+        case AXP173_BATT_CHARGING:
+            return "Battery: Charging";
+        case AXP173_BATT_DISCHARGING:
+            return "Battery: Discharging";
+        default:
+            return "Battery: Unknown";
+        }
+    } break;
+
+    case AXP173_DEBUG_INPUT_STATUS: {
+        int s = axp173_input_status();
+        const char* ac = (s & AXP173_INPUT_AC) ? " AC" : "";
+        const char* usb = (s & AXP173_INPUT_USB) ? " USB" : "";
+        const char* batt = (s & AXP173_INPUT_BATTERY) ? " Battery" : "";
+        snprintf(buf, buflen, "Inputs:%s%s%s", ac, usb, batt);
+        return buf;
+    } break;
+
+    case AXP173_DEBUG_ADC_RATE: {
+        int rate = 25 << axp173_adc_get_rate();
+        snprintf(buf, buflen, "ADC sample rate: %d Hz", rate);
+        return buf;
+    } break;
+
+    default:
+        return "---";
+    }
+}
+
+bool axp173_debug_menu(void)
+{
+    struct simplelist_info info;
+    simplelist_info_init(&info, "AXP173 debug", AXP173_DEBUG_ENTRIES, NULL);
+    info.action_callback = axp173_debug_menu_cb;
+    info.get_name = axp173_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 = axp173_input_status();
+
+    if(input_status & AXP173_INPUT_AC)
+        state |= POWER_INPUT_MAIN_CHARGER;
+
+    if(input_status & AXP173_INPUT_USB)
+        state |= POWER_INPUT_USB_CHARGER;
+
+#ifdef HAVE_BATTERY_SWITCH
+    if(input_status & AXP173_INPUT_BATTERY)
+        state |= POWER_INPUT_BATTERY;
+#endif
+
+    return state;
+}
diff --git a/firmware/drivers/rtc/rtc_x1000.c b/firmware/drivers/rtc/rtc_x1000.c
new file mode 100644
index 0000000000..1d3a5484e9
--- /dev/null
+++ b/firmware/drivers/rtc/rtc_x1000.c
@@ -0,0 +1,104 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2021 Aidan MacDonald
+ *
+ * Based mainly on rtc_jz4760.c,
+ *   Copyright (C) 2016 by Roman Stolyarov
+ *
+ * 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 "rtc.h"
+#include "x1000/rtc.h"
+#include <stdint.h>
+
+/* 4 byte magic number 'RTCV' */
+#define RTCV 0x52544356
+
+/* expected RTC clock frequency */
+#define NC1HZ_EXPECTED (32768 - 1)
+
+static void rtc_write_reg(uint32_t addr, uint32_t value)
+{
+    while(jz_readf(RTC_CR, WRDY) == 0);
+    REG_RTC_WENR = 0xa55a;
+    while(jz_readf(RTC_WENR, WEN) == 0);
+    while(jz_readf(RTC_CR, WRDY) == 0);
+    (*(volatile uint32_t*)addr) = value;
+    while(jz_readf(RTC_CR, WRDY) == 0);
+}
+
+void rtc_init(void)
+{
+    /* Check if we totally lost power and need to reset the RTC */
+    if(REG_RTC_HSPR != RTCV || jz_readf(RTC_GR, NC1HZ) != NC1HZ_EXPECTED) {
+        rtc_write_reg(JA_RTC_GR, NC1HZ_EXPECTED);
+        rtc_write_reg(JA_RTC_HWFCR, 3200);
+        rtc_write_reg(JA_RTC_HRCR, 2048);
+        rtc_write_reg(JA_RTC_SR, 1546300800); /* 01/01/2019 */
+        rtc_write_reg(JA_RTC_CR, 1);
+        rtc_write_reg(JA_RTC_HSPR, RTCV);
+    }
+
+    rtc_write_reg(JA_RTC_HWRSR, 0);
+}
+
+int rtc_read_datetime(struct tm* tm)
+{
+    time_t time = REG_RTC_SR;
+    gmtime_r(&time, tm);
+    return 1;
+}
+
+int rtc_write_datetime(const struct tm* tm)
+{
+    time_t time = mktime((struct tm*)tm);
+    rtc_write_reg(JA_RTC_SR, time);
+    return 1;
+}
+
+#ifdef HAVE_RTC_ALARM
+/* TODO: implement the RTC alarm */
+
+void rtc_set_alarm(int h, int m)
+{
+    (void)h;
+    (void)m;
+}
+
+void rtc_get_alarm(int* h, int* m)
+{
+    (void)h;
+    (void)m;
+}
+
+void rtc_enable_alarm(bool enable)
+{
+    (void)enable;
+}
+
+bool rtc_check_alarm_started(bool release_alarm)
+{
+    (void)release_alarm;
+    return false;
+}
+
+bool rtc_check_alarm_flag(void)
+{
+    return false;
+}
+#endif