esp-idf/components/bootloader_support/src/bootloader_random_esp32.c
2020-10-16 18:48:26 +11:00

129 lines
5.7 KiB
C

// Copyright 2016-2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "sdkconfig.h"
#include "bootloader_random.h"
#include "soc/rtc_periph.h"
#include "soc/sens_periph.h"
#include "soc/syscon_periph.h"
#include "soc/dport_reg.h"
#include "soc/i2s_periph.h"
#include "esp_log.h"
#include "soc/io_mux_reg.h"
#ifndef BOOTLOADER_BUILD
#include "driver/periph_ctrl.h"
#endif
void bootloader_random_enable(void)
{
/* Ensure the hardware RNG is enabled following a soft reset. This should always be the case already (this clock is
never disabled while the CPU is running), this is a "belts and braces" type check.
*/
#ifdef BOOTLOADER_BUILD
DPORT_SET_PERI_REG_MASK(DPORT_WIFI_CLK_EN_REG, DPORT_WIFI_CLK_RNG_EN);
#else
periph_module_enable(PERIPH_RNG_MODULE);
#endif // BOOTLOADER_BUILD
/* Enable SAR ADC in test mode to feed ADC readings of the 1.1V
reference via I2S into the RNG entropy input.
Note: I2S requires the PLL to be running, so the call to rtc_set_cpu_freq(CPU_80M)
in early bootloader startup must have been made.
*/
SET_PERI_REG_BITS(RTC_CNTL_TEST_MUX_REG, RTC_CNTL_DTEST_RTC, 2, RTC_CNTL_DTEST_RTC_S);
SET_PERI_REG_MASK(RTC_CNTL_TEST_MUX_REG, RTC_CNTL_ENT_RTC);
SET_PERI_REG_MASK(SENS_SAR_START_FORCE_REG, SENS_SAR2_EN_TEST);
#ifdef BOOTLOADER_BUILD
DPORT_SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG, DPORT_I2S0_CLK_EN);
#else
periph_module_enable(PERIPH_I2S0_MODULE);
#endif // BOOTLOADER_BUILD
CLEAR_PERI_REG_MASK(SENS_SAR_START_FORCE_REG, SENS_ULP_CP_FORCE_START_TOP);
CLEAR_PERI_REG_MASK(SENS_SAR_START_FORCE_REG, SENS_ULP_CP_START_TOP);
// Test pattern configuration byte 0xAD:
//--[7:4] channel_sel: 10-->en_test
//--[3:2] bit_width : 3-->12bit
//--[1:0] atten : 1-->3dB attenuation
WRITE_PERI_REG(SYSCON_SARADC_SAR2_PATT_TAB1_REG, 0xADADADAD);
WRITE_PERI_REG(SYSCON_SARADC_SAR2_PATT_TAB2_REG, 0xADADADAD);
WRITE_PERI_REG(SYSCON_SARADC_SAR2_PATT_TAB3_REG, 0xADADADAD);
WRITE_PERI_REG(SYSCON_SARADC_SAR2_PATT_TAB4_REG, 0xADADADAD);
SET_PERI_REG_BITS(SENS_SAR_MEAS_WAIT2_REG, SENS_FORCE_XPD_SAR, 3, SENS_FORCE_XPD_SAR_S);
SET_PERI_REG_MASK(SENS_SAR_READ_CTRL_REG, SENS_SAR1_DIG_FORCE);
SET_PERI_REG_MASK(SENS_SAR_READ_CTRL2_REG, SENS_SAR2_DIG_FORCE);
SET_PERI_REG_MASK(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_SAR2_MUX);
SET_PERI_REG_BITS(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_SAR_CLK_DIV, 4, SYSCON_SARADC_SAR_CLK_DIV_S);
SET_PERI_REG_BITS(SYSCON_SARADC_FSM_REG, SYSCON_SARADC_RSTB_WAIT, 8, SYSCON_SARADC_RSTB_WAIT_S); /* was 1 */
SET_PERI_REG_BITS(SYSCON_SARADC_FSM_REG, SYSCON_SARADC_START_WAIT, 10, SYSCON_SARADC_START_WAIT_S);
SET_PERI_REG_BITS(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_WORK_MODE, 0, SYSCON_SARADC_WORK_MODE_S);
SET_PERI_REG_MASK(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_SAR_SEL);
CLEAR_PERI_REG_MASK(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_DATA_SAR_SEL);
SET_PERI_REG_BITS(I2S_SAMPLE_RATE_CONF_REG(0), I2S_RX_BCK_DIV_NUM, 20, I2S_RX_BCK_DIV_NUM_S);
SET_PERI_REG_MASK(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_DATA_TO_I2S);
CLEAR_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_CAMERA_EN);
SET_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_LCD_EN);
SET_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_DATA_ENABLE);
SET_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_DATA_ENABLE_TEST_EN);
SET_PERI_REG_MASK(I2S_CONF_REG(0), I2S_RX_START);
}
void bootloader_random_disable(void)
{
/* Reset some i2s configuration (possibly redundant as we reset entire
I2S peripheral further down). */
CLEAR_PERI_REG_MASK(I2S_CONF_REG(0), I2S_RX_START);
SET_PERI_REG_MASK(I2S_CONF_REG(0), I2S_RX_RESET);
CLEAR_PERI_REG_MASK(I2S_CONF_REG(0), I2S_RX_RESET);
CLEAR_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_CAMERA_EN);
CLEAR_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_LCD_EN);
CLEAR_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_DATA_ENABLE_TEST_EN);
CLEAR_PERI_REG_MASK(I2S_CONF2_REG(0), I2S_DATA_ENABLE);
/* Disable i2s clock */
#ifdef BOOTLOADER_BUILD
DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG, DPORT_I2S0_CLK_EN);
#else
periph_module_disable(PERIPH_I2S0_MODULE);
#endif // BOOTLOADER_BUILD
/* Restore SYSCON mode registers */
CLEAR_PERI_REG_MASK(SENS_SAR_READ_CTRL_REG, SENS_SAR1_DIG_FORCE);
CLEAR_PERI_REG_MASK(SENS_SAR_READ_CTRL2_REG, SENS_SAR2_DIG_FORCE);
/* Restore SAR ADC mode */
CLEAR_PERI_REG_MASK(SENS_SAR_START_FORCE_REG, SENS_SAR2_EN_TEST);
CLEAR_PERI_REG_MASK(SYSCON_SARADC_CTRL_REG, SYSCON_SARADC_SAR2_MUX
| SYSCON_SARADC_SAR_SEL | SYSCON_SARADC_DATA_TO_I2S);
SET_PERI_REG_BITS(SENS_SAR_MEAS_WAIT2_REG, SENS_FORCE_XPD_SAR, 0, SENS_FORCE_XPD_SAR_S);
SET_PERI_REG_BITS(SYSCON_SARADC_FSM_REG, SYSCON_SARADC_START_WAIT, 8, SYSCON_SARADC_START_WAIT_S);
/* Reset i2s peripheral */
#ifdef BOOTLOADER_BUILD
DPORT_SET_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_I2S0_RST);
DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_I2S0_RST);
#else
periph_module_reset(PERIPH_I2S0_MODULE);
#endif
/* Disable pull supply voltage to SAR ADC */
CLEAR_PERI_REG_MASK(RTC_CNTL_TEST_MUX_REG, RTC_CNTL_ENT_RTC);
SET_PERI_REG_BITS(RTC_CNTL_TEST_MUX_REG, RTC_CNTL_DTEST_RTC, 0, RTC_CNTL_DTEST_RTC_S);
}