esp_hal/soc/esp32c2/efuse/
mod.rs

1//! # Reading of eFuses (ESP32-C2)
2//!
3//! ## Overview
4//! The `efuse` module provides functionality for reading eFuse data
5//! from the `ESP32-C2` chip, allowing access to various chip-specific
6//! information such as:
7//!
8//!   * MAC address
9//!   * ADC calibration information
10//!
11//! and more. It is useful for retrieving chip-specific configuration and
12//! identification data during runtime.
13//!
14//! The `Efuse` struct represents the eFuse peripheral and is responsible for
15//! reading various eFuse fields and values.
16//!
17//! ## Examples
18//!
19//! ### Read data from the eFuse storage.
20//!
21//! ```rust, no_run
22#![doc = crate::before_snippet!()]
23//! # use esp_hal::efuse::Efuse;
24//!
25//! let mac_address = Efuse::read_base_mac_address();
26//!
27//! println!(
28//!     "MAC: {:#X}:{:#X}:{:#X}:{:#X}:{:#X}:{:#X}",
29//!     mac_address[0],
30//!     mac_address[1],
31//!     mac_address[2],
32//!     mac_address[3],
33//!     mac_address[4],
34//!     mac_address[5]
35//! );
36//!
37//! println!("MAC address {:02x?}", Efuse::mac_address());
38//! println!("Flash Encryption {:?}", Efuse::flash_encryption());
39//! # Ok(())
40//! # }
41//! ```
42
43pub use self::fields::*;
44use crate::{analog::adc::Attenuation, peripherals::EFUSE, soc::efuse_field::EfuseField};
45
46mod fields;
47
48/// A struct representing the eFuse functionality of the chip.
49pub struct Efuse;
50
51impl Efuse {
52    /// Get status of SPI boot encryption.
53    pub fn flash_encryption() -> bool {
54        (Self::read_field_le::<u8>(SPI_BOOT_CRYPT_CNT).count_ones() % 2) != 0
55    }
56
57    /// Get the multiplier for the timeout value of the RWDT STAGE 0 register.
58    pub fn rwdt_multiplier() -> u8 {
59        Self::read_field_le::<u8>(WDT_DELAY_SEL)
60    }
61
62    /// Get efuse block version
63    ///
64    /// see <https://github.com/espressif/esp-idf/blob/dc016f5987/components/hal/efuse_hal.c#L27-L30>
65    pub fn block_version() -> (u8, u8) {
66        // see <https://github.com/espressif/esp-idf/blob/dc016f5987/components/hal/esp32c2/include/hal/efuse_ll.h#L65-L73>
67        // <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_table.csv#L90-L91>
68        (
69            Self::read_field_le::<u8>(BLK_VERSION_MAJOR),
70            Self::read_field_le::<u8>(BLK_VERSION_MINOR),
71        )
72    }
73
74    /// Get version of RTC calibration block
75    ///
76    /// see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_rtc_calib.c#L14>
77    pub fn rtc_calib_version() -> u8 {
78        let (major, _minor) = Self::block_version();
79        if major == 0 { 1 } else { 0 }
80    }
81
82    /// Get ADC initial code for specified attenuation from efuse
83    ///
84    /// see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_rtc_calib.c#L27>
85    pub fn rtc_calib_init_code(_unit: u8, atten: Attenuation) -> Option<u16> {
86        let version = Self::rtc_calib_version();
87
88        if version != 1 {
89            return None;
90        }
91
92        // see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_table.csv#L94>
93        let diff_code0: u16 = Self::read_field_le(ADC1_INIT_CODE_ATTEN0);
94        let code0 = if diff_code0 & (1 << 7) != 0 {
95            2160 - (diff_code0 & 0x7f)
96        } else {
97            2160 + diff_code0
98        };
99
100        if matches!(atten, Attenuation::_0dB) {
101            return Some(code0);
102        }
103
104        // see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_table.csv#L95>
105        let diff_code11: u16 = Self::read_field_le(ADC1_INIT_CODE_ATTEN3);
106        let code11 = code0 + diff_code11;
107
108        Some(code11)
109    }
110
111    /// Get ADC reference point voltage for specified attenuation in millivolts
112    ///
113    /// see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_rtc_calib.c#L65>
114    pub fn rtc_calib_cal_mv(_unit: u8, atten: Attenuation) -> u16 {
115        match atten {
116            Attenuation::_0dB => 400,
117            Attenuation::_11dB => 1370,
118        }
119    }
120
121    /// Get ADC reference point digital code for specified attenuation
122    ///
123    /// see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_rtc_calib.c#L65>
124    pub fn rtc_calib_cal_code(_unit: u8, atten: Attenuation) -> Option<u16> {
125        let version = Self::rtc_calib_version();
126
127        if version != 1 {
128            return None;
129        }
130
131        // see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_table.csv#L96>
132        let diff_code0: u16 = Self::read_field_le(ADC1_CAL_VOL_ATTEN0);
133        let code0 = if diff_code0 & (1 << 7) != 0 {
134            1540 - (diff_code0 & 0x7f)
135        } else {
136            1540 + diff_code0
137        };
138
139        if matches!(atten, Attenuation::_0dB) {
140            return Some(code0);
141        }
142
143        // see <https://github.com/espressif/esp-idf/blob/903af13e8/components/efuse/esp32c2/esp_efuse_table.csv#L97>
144        let diff_code11: u16 = Self::read_field_le(ADC1_CAL_VOL_ATTEN3);
145        let code11 = if diff_code0 & (1 << 5) != 0 {
146            code0 - (diff_code11 & 0x1f)
147        } else {
148            code0 + diff_code11
149        } - 123;
150
151        Some(code11)
152    }
153}
154
155#[derive(Debug, Clone, Copy, strum::FromRepr)]
156#[repr(u32)]
157pub(crate) enum EfuseBlock {
158    Block0,
159    Block1,
160    Block2,
161    Block3,
162}
163
164impl EfuseBlock {
165    pub(crate) fn address(self) -> *const u32 {
166        let efuse = EFUSE::regs();
167        match self {
168            Self::Block0 => efuse.rd_wr_dis().as_ptr(),
169            Self::Block1 => efuse.rd_blk1_data0().as_ptr(),
170            Self::Block2 => efuse.rd_blk2_data0().as_ptr(),
171            Self::Block3 => efuse.rd_blk3_data0().as_ptr(),
172        }
173    }
174}
esp_hal/soc/esp32c2/efuse/mod.rs

esp_hal/soc/esp32c2/efuse/
mod.rs
