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/*
* Copyright 2023 jacqueline <me@jacqueline.id.au>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#include "drivers/samd.hpp"
#include <cstdint>
#include <format>
#include <optional>
#include <string>
#include "esp_err.h"
#include "esp_log.h"
#include "hal/gpio_types.h"
#include "hal/i2c_types.h"
#include "drivers/i2c.hpp"
#include "drivers/nvs.hpp"
static const uint8_t kAddress = 0x45;
[[maybe_unused]] static const char kTag[] = "SAMD";
namespace drivers {
static constexpr gpio_num_t kIntPin = GPIO_NUM_35;
auto Samd::chargeStatusToString(ChargeStatus status) -> std::string {
switch (status) {
case ChargeStatus::kNoBattery:
return "no_battery";
case ChargeStatus::kBatteryCritical:
return "critical";
case ChargeStatus::kDischarging:
return "discharging";
case ChargeStatus::kChargingRegular:
return "charge_regular";
case ChargeStatus::kChargingFast:
return "charge_fast";
case ChargeStatus::kFullCharge:
return "full_charge";
case ChargeStatus::kFault:
return "fault";
case ChargeStatus::kUnknown:
default:
return "unknown";
}
}
Samd::Samd(NvsStorage& nvs) : nvs_(nvs) {
gpio_set_direction(kIntPin, GPIO_MODE_INPUT);
// Being able to interface with the SAMD properly is critical. To ensure we
// will be able to, we begin by checking the I2C protocol version is
// compatible, and throw if it's not.
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kSamdFirmwareMajorVersion))
.start()
.write_addr(kAddress, I2C_MASTER_READ)
.read(&version_major_, I2C_MASTER_ACK)
.read(&version_minor_, I2C_MASTER_NACK)
.stop();
ESP_ERROR_CHECK(transaction.Execute(1));
if (version_major_ < 6) {
version_minor_ = 0;
}
ESP_LOGI(kTag, "samd firmware rev: %u.%u", version_major_, version_minor_);
UpdateChargeStatus();
UpdateUsbStatus();
SetFastChargeEnabled(nvs.FastCharge());
}
Samd::~Samd() {}
auto Samd::Version() -> std::string {
return std::format("{}.{}", version_major_, version_minor_);
}
auto Samd::GetChargeStatus() -> std::optional<ChargeStatus> {
return charge_status_;
}
auto Samd::UpdateChargeStatus() -> void {
uint8_t raw_res;
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kChargeStatus))
.start()
.write_addr(kAddress, I2C_MASTER_READ)
.read(&raw_res, I2C_MASTER_NACK)
.stop();
esp_err_t res = transaction.Execute(1);
if (res != ESP_OK) {
return;
}
// Lower two bits are the usb power status, next three are the BMS status.
// See 'gpio.c' in the SAMD21 firmware for how these bits get packed.
uint8_t charge_state = (raw_res & 0b11100) >> 2;
uint8_t usb_state = raw_res & 0b11;
switch (charge_state) {
case 0b000:
charge_status_ = ChargeStatus::kNoBattery;
break;
case 0b001:
// BMS says we're charging; work out how fast we're charging.
if (usb_state >= 0b10 && nvs_.FastCharge()) {
charge_status_ = ChargeStatus::kChargingFast;
} else {
charge_status_ = ChargeStatus::kChargingRegular;
}
break;
case 0b010:
charge_status_ = ChargeStatus::kFullCharge;
break;
case 0b011:
charge_status_ = ChargeStatus::kFault;
break;
case 0b100:
charge_status_ = ChargeStatus::kBatteryCritical;
break;
case 0b101:
charge_status_ = ChargeStatus::kDischarging;
break;
case 0b110:
case 0b111:
charge_status_ = ChargeStatus::kUnknown;
break;
}
}
auto Samd::GetUsbStatus() -> UsbStatus {
return usb_status_;
}
auto Samd::UpdateUsbStatus() -> void {
uint8_t raw_res;
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kUsbStatus))
.start()
.write_addr(kAddress, I2C_MASTER_READ)
.read(&raw_res, I2C_MASTER_NACK)
.stop();
esp_err_t res = transaction.Execute(1);
if (res != ESP_OK) {
return;
}
if (!(raw_res & 0b1)) {
usb_status_ = UsbStatus::kDetached;
}
usb_status_ =
(raw_res & 0b10) ? UsbStatus::kAttachedBusy : UsbStatus::kAttachedIdle;
}
auto Samd::ResetToFlashSamd() -> void {
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kUsbControl), 0b100)
.stop();
ESP_ERROR_CHECK(transaction.Execute(3));
}
auto Samd::SetFastChargeEnabled(bool en) -> void {
// Always update NVS, so that the setting is right after the SAMD firmware is
// updated.
nvs_.FastCharge(en);
if (version_major_ < 4) {
return;
}
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kPowerControl), (en << 1))
.stop();
ESP_ERROR_CHECK(transaction.Execute(3));
}
auto Samd::PowerDown() -> void {
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kPowerControl), 0b1)
.stop();
ESP_ERROR_CHECK(transaction.Execute(3));
}
auto Samd::UsbMassStorage(bool en) -> void {
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kUsbControl), en)
.stop();
ESP_ERROR_CHECK(transaction.Execute(3));
}
auto Samd::UsbMassStorage() -> bool {
uint8_t raw_res;
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(registerIdx(RegisterName::kUsbControl))
.start()
.write_addr(kAddress, I2C_MASTER_READ)
.read(&raw_res, I2C_MASTER_NACK)
.stop();
esp_err_t res = transaction.Execute(1);
if (res != ESP_OK) {
return false;
}
return raw_res & 1;
}
auto Samd::registerIdx(RegisterName r) -> uint8_t {
switch (r) {
case RegisterName::kSamdFirmwareMajorVersion:
// Register 0 is always the major version.
return 0;
case RegisterName::kSamdFirmwareMinorVersion:
// Firmwares before version 6 had no minor :(
return version_major_ >= 6 ? 1 : 0;
case RegisterName::kChargeStatus:
return version_major_ >= 6 ? 2 : 1;
case RegisterName::kUsbStatus:
return version_major_ >= 6 ? 3 : 2;
case RegisterName::kPowerControl:
return version_major_ >= 6 ? 4 : 3;
case RegisterName::kUsbControl:
return version_major_ >= 6 ? 5 : 4;
}
assert(false); // very very bad!!!
return 0;
}
} // namespace drivers
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