1 /*
2 * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6 #include "sdkconfig.h"
7 #include "bootloader_random.h"
8 #include "esp_log.h"
9 #include "soc/syscon_reg.h"
10 #include "soc/rtc_cntl_reg.h"
11 #include "soc/apb_saradc_reg.h"
12 #include "soc/system_reg.h"
13 #include "esp_private/regi2c_ctrl.h"
14 #include "soc/regi2c_saradc.h"
15
soc_random_enable(void)16 void soc_random_enable(void)
17 {
18 /* RNG module is always clock enabled */
19 REG_SET_FIELD(RTC_CNTL_SENSOR_CTRL_REG, RTC_CNTL_FORCE_XPD_SAR, 0x3);
20 SET_PERI_REG_MASK(RTC_CNTL_ANA_CONF_REG, RTC_CNTL_SAR_I2C_PU_M);
21
22 // Bridging sar2 internal reference voltage
23 REGI2C_WRITE_MASK(I2C_SAR_ADC, ADC_SARADC2_ENCAL_REF_ADDR, 1);
24 REGI2C_WRITE_MASK(I2C_SAR_ADC, ADC_SARADC_DTEST_RTC_ADDR, 0);
25 REGI2C_WRITE_MASK(I2C_SAR_ADC, ADC_SARADC_ENT_RTC_ADDR, 0);
26 REGI2C_WRITE_MASK(I2C_SAR_ADC, ADC_SARADC_ENT_TSENS_ADDR, 0);
27
28 // Enable SAR ADC2 internal channel to read adc2 ref voltage for additional entropy
29 SET_PERI_REG_MASK(SYSTEM_PERIP_CLK_EN0_REG, SYSTEM_APB_SARADC_CLK_EN_M);
30 CLEAR_PERI_REG_MASK(SYSTEM_PERIP_RST_EN0_REG, SYSTEM_APB_SARADC_RST_M);
31 REG_SET_FIELD(APB_SARADC_APB_ADC_CLKM_CONF_REG, APB_SARADC_REG_CLK_SEL, 0x2);
32 SET_PERI_REG_MASK(APB_SARADC_APB_ADC_CLKM_CONF_REG, APB_SARADC_CLK_EN_M);
33 SET_PERI_REG_MASK(APB_SARADC_CTRL_REG, APB_SARADC_SAR_CLK_GATED_M);
34 REG_SET_FIELD(APB_SARADC_CTRL_REG, APB_SARADC_XPD_SAR_FORCE, 0x3);
35 REG_SET_FIELD(APB_SARADC_CTRL_REG, APB_SARADC_SAR_CLK_DIV, 1);
36
37 REG_SET_FIELD(APB_SARADC_FSM_WAIT_REG, APB_SARADC_RSTB_WAIT, 8);
38 REG_SET_FIELD(APB_SARADC_FSM_WAIT_REG, APB_SARADC_XPD_WAIT, 5);
39 REG_SET_FIELD(APB_SARADC_FSM_WAIT_REG, APB_SARADC_STANDBY_WAIT, 100);
40
41 SET_PERI_REG_MASK(APB_SARADC_CTRL_REG, APB_SARADC_SAR_PATT_P_CLEAR_M);
42 CLEAR_PERI_REG_MASK(APB_SARADC_CTRL_REG, APB_SARADC_SAR_PATT_P_CLEAR_M);
43 REG_SET_FIELD(APB_SARADC_CTRL_REG, APB_SARADC_SAR_PATT_LEN, 0);
44 REG_SET_FIELD(APB_SARADC_SAR_PATT_TAB1_REG, APB_SARADC_SAR_PATT_TAB1,
45 0x9cffff); // Set adc2 internal channel & atten
46 REG_SET_FIELD(APB_SARADC_SAR_PATT_TAB2_REG, APB_SARADC_SAR_PATT_TAB2, 0xffffff);
47 // Set ADC sampling frequency
48 REG_SET_FIELD(APB_SARADC_CTRL2_REG, APB_SARADC_TIMER_TARGET, 100);
49 REG_SET_FIELD(APB_SARADC_APB_ADC_CLKM_CONF_REG, APB_SARADC_REG_CLKM_DIV_NUM, 15);
50 CLEAR_PERI_REG_MASK(APB_SARADC_CTRL2_REG, APB_SARADC_MEAS_NUM_LIMIT);
51 SET_PERI_REG_MASK(APB_SARADC_DMA_CONF_REG, APB_SARADC_APB_ADC_TRANS_M);
52 SET_PERI_REG_MASK(APB_SARADC_CTRL2_REG, APB_SARADC_TIMER_EN);
53 }
54
soc_random_disable(void)55 void soc_random_disable(void)
56 {
57 /* Restore internal I2C bus state */
58 REGI2C_WRITE_MASK(I2C_SAR_ADC, ADC_SARADC2_ENCAL_REF_ADDR, 0);
59
60 /* Restore SARADC to default mode */
61 CLEAR_PERI_REG_MASK(APB_SARADC_CTRL2_REG, APB_SARADC_TIMER_EN);
62 CLEAR_PERI_REG_MASK(APB_SARADC_DMA_CONF_REG, APB_SARADC_APB_ADC_TRANS_M);
63 REG_SET_FIELD(APB_SARADC_SAR_PATT_TAB1_REG, APB_SARADC_SAR_PATT_TAB1, 0xffffff);
64 REG_SET_FIELD(APB_SARADC_SAR_PATT_TAB2_REG, APB_SARADC_SAR_PATT_TAB2, 0xffffff);
65 CLEAR_PERI_REG_MASK(APB_SARADC_APB_ADC_CLKM_CONF_REG, APB_SARADC_CLK_EN_M);
66 REG_SET_FIELD(APB_SARADC_CTRL_REG, APB_SARADC_XPD_SAR_FORCE, 0);
67 REG_SET_FIELD(RTC_CNTL_SENSOR_CTRL_REG, RTC_CNTL_FORCE_XPD_SAR, 0);
68 }
69
