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/*
* Copyright 2023 jacqueline <me@jacqueline.id.au>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#include "wm8523.hpp"
#include <cstdint>
#include "esp_err.h"
#include "hal/i2c_types.h"
#include "i2c.hpp"
namespace drivers {
namespace wm8523 {
const uint16_t kAbsoluteMaxVolume = 0x1ff;
const uint16_t kAbsoluteMinVolume = 0b0;
// This is 3dB below what the DAC considers to be '0dB', and 9.5dB above line
// level reference.
const uint16_t kMaxVolumeBeforeClipping = 0x184;
// This is 12.5 dB below what the DAC considers to be '0dB'.
const uint16_t kLineLevelReferenceVolume = 0x15E;
// Default to -24 dB, which I will claim is 'arbitrarily chosen to be safe but
// audible', but is in fact just a nice value for my headphones in particular.
const uint16_t kDefaultVolume = kLineLevelReferenceVolume - 96;
// Default to +6dB == 2Vrms == 'CD Player'
const uint16_t kDefaultMaxVolume = kLineLevelReferenceVolume + 12;
static const uint8_t kAddress = 0b0011010;
auto ReadRegister(Register reg) -> std::optional<uint16_t> {
uint8_t msb, lsb;
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(static_cast<uint8_t>(reg))
.start()
.write_addr(kAddress, I2C_MASTER_READ)
.read(&msb, I2C_MASTER_ACK)
.read(&lsb, I2C_MASTER_LAST_NACK)
.stop();
if (transaction.Execute() != ESP_OK) {
return {};
}
return (msb << 8) & lsb;
}
auto WriteRegister(Register reg, uint16_t data) -> bool {
return WriteRegister(reg, (data >> 8) & 0xFF, data & 0xFF);
}
auto WriteRegister(Register reg, uint8_t msb, uint8_t lsb) -> bool {
I2CTransaction transaction;
transaction.start()
.write_addr(kAddress, I2C_MASTER_WRITE)
.write_ack(static_cast<uint8_t>(reg), msb, lsb)
.stop();
return transaction.Execute() == ESP_OK;
}
} // namespace wm8523
} // namespace drivers
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