// Copyright 2015-2017 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 #include #include #include #include "rom/ets_sys.h" #include "rom/rtc.h" #include "rom/uart.h" #include "soc/rtc.h" #include "soc/rtc_cntl_reg.h" #include "soc/rtc_io_reg.h" #include "soc/sens_reg.h" #include "soc/dport_reg.h" #include "soc/efuse_reg.h" #include "soc/apb_ctrl_reg.h" #include "i2c_rtc_clk.h" #include "soc_log.h" #include "sdkconfig.h" #include "xtensa/core-macros.h" #define MHZ (1000000) /* Frequency of the 8M oscillator is 8.5MHz +/- 5%, at the default DCAP setting */ #define RTC_FAST_CLK_FREQ_8M 8500000 #define RTC_SLOW_CLK_FREQ_150K 150000 #define RTC_SLOW_CLK_FREQ_8MD256 (RTC_FAST_CLK_FREQ_8M / 256) #define RTC_SLOW_CLK_FREQ_32K 32768 static const char* TAG = "rtc_clk"; /* Various constants related to the analog internals of the chip. * Defined here because they don't have any use outside of this file. */ #define BBPLL_ENDIV5_VAL_320M 0x43 #define BBPLL_BBADC_DSMP_VAL_320M 0x84 #define BBPLL_ENDIV5_VAL_480M 0xc3 #define BBPLL_BBADC_DSMP_VAL_480M 0x74 #define APLL_SDM_STOP_VAL_1 0x09 #define APLL_SDM_STOP_VAL_2_REV0 0x69 #define APLL_SDM_STOP_VAL_2_REV1 0x49 #define APLL_CAL_DELAY_1 0x0f #define APLL_CAL_DELAY_2 0x3f #define APLL_CAL_DELAY_3 0x1f #define XTAL_32K_DAC_VAL 1 #define XTAL_32K_DRES_VAL 3 #define XTAL_32K_DBIAS_VAL 0 #define XTAL_32K_BOOTSTRAP_DAC_VAL 3 #define XTAL_32K_BOOTSTRAP_DRES_VAL 3 #define XTAL_32K_BOOTSTRAP_DBIAS_VAL 0 #define XTAL_32K_BOOTSTRAP_TIME_US 7 /* Delays for various clock sources to be enabled/switched. * All values are in microseconds. * TODO: some of these are excessive, and should be reduced. */ #define DELAY_CPU_FREQ_SWITCH_TO_XTAL_WITH_150K 20 #define DELAY_CPU_FREQ_SWITCH_TO_XTAL_WITH_32K 160 #define DELAY_CPU_FREQ_SWITCH_TO_PLL 20 #define DELAY_PLL_DBIAS_RAISE 3 #define DELAY_PLL_ENABLE_WITH_150K 80 #define DELAY_PLL_ENABLE_WITH_32K 160 #define DELAY_FAST_CLK_SWITCH 3 #define DELAY_SLOW_CLK_SWITCH 300 #define DELAY_8M_ENABLE 50 /* Number of 8M/256 clock cycles to use for XTAL frequency estimation. * 10 cycles will take approximately 300 microseconds. */ #define XTAL_FREQ_EST_CYCLES 10 static rtc_cpu_freq_t s_cur_freq = RTC_CPU_FREQ_XTAL; static int s_pll_freq = 0; static void rtc_clk_32k_enable_internal(int dac, int dres, int dbias) { SET_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_X32N_MUX_SEL | RTC_IO_X32P_MUX_SEL); CLEAR_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_X32P_RDE | RTC_IO_X32P_RUE | RTC_IO_X32N_RUE | RTC_IO_X32N_RDE | RTC_IO_X32N_MUX_SEL | RTC_IO_X32P_MUX_SEL); REG_SET_FIELD(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_DAC_XTAL_32K, dac); REG_SET_FIELD(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_DRES_XTAL_32K, dres); REG_SET_FIELD(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_DBIAS_XTAL_32K, dbias); SET_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_XPD_XTAL_32K); } void rtc_clk_32k_enable(bool enable) { if (enable) { rtc_clk_32k_enable_internal(XTAL_32K_DAC_VAL, XTAL_32K_DRES_VAL, XTAL_32K_DBIAS_VAL); } else { CLEAR_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_XPD_XTAL_32K); } } void rtc_clk_32k_bootstrap() { CLEAR_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_XPD_XTAL_32K); SET_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_X32P_RUE | RTC_IO_X32N_RDE); ets_delay_us(XTAL_32K_BOOTSTRAP_TIME_US); rtc_clk_32k_enable_internal(XTAL_32K_BOOTSTRAP_DAC_VAL, XTAL_32K_BOOTSTRAP_DRES_VAL, XTAL_32K_BOOTSTRAP_DBIAS_VAL); } bool rtc_clk_32k_enabled() { return GET_PERI_REG_MASK(RTC_IO_XTAL_32K_PAD_REG, RTC_IO_XPD_XTAL_32K) != 0; } void rtc_clk_8m_enable(bool clk_8m_en, bool d256_en) { if (clk_8m_en) { CLEAR_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ENB_CK8M); /* no need to wait once enabled by software */ REG_SET_FIELD(RTC_CNTL_TIMER1_REG, RTC_CNTL_CK8M_WAIT, 1); if (d256_en) { CLEAR_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ENB_CK8M_DIV); } else { SET_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ENB_CK8M_DIV); } ets_delay_us(DELAY_8M_ENABLE); } else { SET_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ENB_CK8M); REG_SET_FIELD(RTC_CNTL_TIMER1_REG, RTC_CNTL_CK8M_WAIT, RTC_CNTL_CK8M_WAIT_DEFAULT); } } bool rtc_clk_8m_enabled() { return GET_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ENB_CK8M) == 0; } bool rtc_clk_8md256_enabled() { return GET_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ENB_CK8M_DIV) == 0; } void rtc_clk_apll_enable(bool enable, uint32_t sdm0, uint32_t sdm1, uint32_t sdm2, uint32_t o_div) { REG_SET_FIELD(RTC_CNTL_ANA_CONF_REG, RTC_CNTL_PLLA_FORCE_PD, enable ? 0 : 1); REG_SET_FIELD(RTC_CNTL_ANA_CONF_REG, RTC_CNTL_PLLA_FORCE_PU, enable ? 1 : 0); REG_SET_FIELD(RTC_CNTL_OPTIONS0_REG, RTC_CNTL_BIAS_I2C_FORCE_PD, enable ? 0 : 1); if (!enable && REG_GET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL) != RTC_CNTL_SOC_CLK_SEL_PLL) { SET_PERI_REG_MASK(RTC_CNTL_OPTIONS0_REG, RTC_CNTL_BIAS_I2C_FORCE_PD); } if (enable) { uint8_t sdm_stop_val_2 = APLL_SDM_STOP_VAL_2_REV1; uint32_t is_rev0 = (GET_PERI_REG_BITS2(EFUSE_BLK0_RDATA3_REG, 1, 15) == 0); if (is_rev0) { sdm0 = 0; sdm1 = 0; sdm_stop_val_2 = APLL_SDM_STOP_VAL_2_REV0; } I2C_WRITEREG_MASK_RTC(I2C_APLL, I2C_APLL_DSDM2, sdm2); I2C_WRITEREG_MASK_RTC(I2C_APLL, I2C_APLL_DSDM0, sdm0); I2C_WRITEREG_MASK_RTC(I2C_APLL, I2C_APLL_DSDM1, sdm1); I2C_WRITEREG_RTC(I2C_APLL, I2C_APLL_SDM_STOP, APLL_SDM_STOP_VAL_1); I2C_WRITEREG_RTC(I2C_APLL, I2C_APLL_SDM_STOP, sdm_stop_val_2); I2C_WRITEREG_MASK_RTC(I2C_APLL, I2C_APLL_OR_OUTPUT_DIV, o_div); /* calibration */ I2C_WRITEREG_RTC(I2C_APLL, I2C_APLL_IR_CAL_DELAY, APLL_CAL_DELAY_1); I2C_WRITEREG_RTC(I2C_APLL, I2C_APLL_IR_CAL_DELAY, APLL_CAL_DELAY_2); I2C_WRITEREG_RTC(I2C_APLL, I2C_APLL_IR_CAL_DELAY, APLL_CAL_DELAY_3); /* wait for calibration end */ while (!(I2C_READREG_MASK_RTC(I2C_APLL, I2C_APLL_OR_CAL_END))) { /* use ets_delay_us so the RTC bus doesn't get flooded */ ets_delay_us(1); } } } void rtc_clk_slow_freq_set(rtc_slow_freq_t slow_freq) { REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ANA_CLK_RTC_SEL, slow_freq); ets_delay_us(DELAY_SLOW_CLK_SWITCH); } rtc_slow_freq_t rtc_clk_slow_freq_get() { return REG_GET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_ANA_CLK_RTC_SEL); } uint32_t rtc_clk_slow_freq_get_hz() { switch(rtc_clk_slow_freq_get()) { case RTC_SLOW_FREQ_RTC: return RTC_SLOW_CLK_FREQ_150K; case RTC_SLOW_FREQ_32K_XTAL: return RTC_SLOW_CLK_FREQ_32K; case RTC_SLOW_FREQ_8MD256: return RTC_SLOW_CLK_FREQ_8MD256; } return 0; } void rtc_clk_fast_freq_set(rtc_fast_freq_t fast_freq) { REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_FAST_CLK_RTC_SEL, fast_freq); ets_delay_us(DELAY_FAST_CLK_SWITCH); } rtc_fast_freq_t rtc_clk_fast_freq_get() { return REG_GET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_FAST_CLK_RTC_SEL); } void rtc_clk_bbpll_set(rtc_xtal_freq_t xtal_freq, rtc_cpu_freq_t cpu_freq) { uint8_t div_ref; uint8_t div7_0; uint8_t div10_8; uint8_t lref; uint8_t dcur; uint8_t bw; if (cpu_freq != RTC_CPU_FREQ_240M) { /* Configure 320M PLL */ switch (xtal_freq) { case RTC_XTAL_FREQ_40M: div_ref = 0; div7_0 = 32; div10_8 = 0; lref = 0; dcur = 6; bw = 3; break; case RTC_XTAL_FREQ_26M: div_ref = 12; div7_0 = 224; div10_8 = 4; lref = 1; dcur = 0; bw = 1; break; case RTC_XTAL_FREQ_24M: div_ref = 11; div7_0 = 224; div10_8 = 4; lref = 1; dcur = 0; bw = 1; break; default: div_ref = 12; div7_0 = 224; div10_8 = 4; lref = 0; dcur = 0; bw = 0; break; } I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_ENDIV5, BBPLL_ENDIV5_VAL_320M); I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_BBADC_DSMP, BBPLL_BBADC_DSMP_VAL_320M); } else { /* Raise the voltage */ REG_SET_FIELD(RTC_CNTL_REG, RTC_CNTL_DIG_DBIAS_WAK, RTC_CNTL_DBIAS_1V25); ets_delay_us(DELAY_PLL_DBIAS_RAISE); /* Configure 480M PLL */ switch (xtal_freq) { case RTC_XTAL_FREQ_40M: div_ref = 0; div7_0 = 28; div10_8 = 0; lref = 0; dcur = 6; bw = 3; break; case RTC_XTAL_FREQ_26M: div_ref = 12; div7_0 = 144; div10_8 = 4; lref = 1; dcur = 0; bw = 1; break; case RTC_XTAL_FREQ_24M: div_ref = 11; div7_0 = 144; div10_8 = 4; lref = 1; dcur = 0; bw = 1; break; default: div_ref = 12; div7_0 = 224; div10_8 = 4; lref = 0; dcur = 0; bw = 0; break; } I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_ENDIV5, BBPLL_ENDIV5_VAL_480M); I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_BBADC_DSMP, BBPLL_BBADC_DSMP_VAL_480M); } uint8_t i2c_bbpll_lref = (lref << 7) | (div10_8 << 4) | (div_ref); uint8_t i2c_bbpll_div_7_0 = div7_0; uint8_t i2c_bbpll_dcur = (bw << 6) | dcur; I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_OC_LREF, i2c_bbpll_lref); I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_OC_DIV_7_0, i2c_bbpll_div_7_0); I2C_WRITEREG_RTC(I2C_BBPLL, I2C_BBPLL_OC_DCUR, i2c_bbpll_dcur); uint32_t delay_pll_en = (rtc_clk_slow_freq_get() == RTC_SLOW_FREQ_RTC) ? DELAY_PLL_ENABLE_WITH_150K : DELAY_PLL_ENABLE_WITH_32K; ets_delay_us(delay_pll_en); } /** * Switch to XTAL frequency. Does not disable the PLL. */ static void rtc_clk_cpu_freq_to_xtal() { rtc_xtal_freq_t xtal_freq = rtc_clk_xtal_freq_get(); ets_update_cpu_frequency(xtal_freq); REG_SET_FIELD(RTC_CNTL_REG, RTC_CNTL_DIG_DBIAS_WAK, RTC_CNTL_DBIAS_1V10); REG_SET_FIELD(APB_CTRL_SYSCLK_CONF_REG, APB_CTRL_PRE_DIV_CNT, 0); REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL, RTC_CNTL_SOC_CLK_SEL_XTL); DPORT_REG_WRITE(DPORT_CPU_PER_CONF_REG, 0); // clear DPORT_CPUPERIOD_SEL rtc_clk_apb_freq_update(xtal_freq * MHZ); s_cur_freq = RTC_CPU_FREQ_XTAL; } /** * Switch to one of PLL-based frequencies. Current frequency can be XTAL or PLL. * PLL must already be enabled. * If switching between frequencies derived from different PLLs (320M and 480M), * fall back to rtc_clk_cpu_freq_set. * @param cpu_freq new CPU frequency */ static void rtc_clk_cpu_freq_to_pll(rtc_cpu_freq_t cpu_freq) { int freq = 0; if ((cpu_freq == RTC_CPU_FREQ_240M && s_pll_freq == 320) || (cpu_freq != RTC_CPU_FREQ_240M && s_pll_freq == 240)) { /* need to switch PLLs, fall back to full implementation */ rtc_clk_cpu_freq_set(cpu_freq); return; } if (cpu_freq == RTC_CPU_FREQ_80M) { DPORT_REG_WRITE(DPORT_CPU_PER_CONF_REG, 0); freq = 80; } else if (cpu_freq == RTC_CPU_FREQ_160M) { DPORT_REG_WRITE(DPORT_CPU_PER_CONF_REG, 1); freq = 160; } else if (cpu_freq == RTC_CPU_FREQ_240M) { REG_SET_FIELD(RTC_CNTL_REG, RTC_CNTL_DIG_DBIAS_WAK, RTC_CNTL_DBIAS_1V25); DPORT_REG_WRITE(DPORT_CPU_PER_CONF_REG, 2); freq = 240; } REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL, RTC_CNTL_SOC_CLK_SEL_PLL); rtc_clk_apb_freq_update(80 * MHZ); ets_update_cpu_frequency(freq); s_cur_freq = cpu_freq; } void rtc_clk_cpu_freq_set_fast(rtc_cpu_freq_t cpu_freq) { if (cpu_freq == s_cur_freq) { return; } else if (cpu_freq == RTC_CPU_FREQ_2M || s_cur_freq == RTC_CPU_FREQ_2M) { /* fall back to full implementation if switch to/from 2M is needed */ rtc_clk_cpu_freq_set(cpu_freq); } else if (cpu_freq == RTC_CPU_FREQ_XTAL) { rtc_clk_cpu_freq_to_xtal(); } else if (cpu_freq > RTC_CPU_FREQ_XTAL) { rtc_clk_cpu_freq_to_pll(cpu_freq); } } void rtc_clk_cpu_freq_set(rtc_cpu_freq_t cpu_freq) { rtc_xtal_freq_t xtal_freq = rtc_clk_xtal_freq_get(); /* Switch CPU to XTAL frequency first */ REG_SET_FIELD(RTC_CNTL_REG, RTC_CNTL_DIG_DBIAS_WAK, RTC_CNTL_DBIAS_1V10); REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL, RTC_CNTL_SOC_CLK_SEL_XTL); REG_SET_FIELD(APB_CTRL_SYSCLK_CONF_REG, APB_CTRL_PRE_DIV_CNT, 0); ets_update_cpu_frequency(xtal_freq); uint32_t delay_xtal_switch = (rtc_clk_slow_freq_get() == RTC_SLOW_FREQ_RTC) ? DELAY_CPU_FREQ_SWITCH_TO_XTAL_WITH_150K : DELAY_CPU_FREQ_SWITCH_TO_XTAL_WITH_32K; ets_delay_us(delay_xtal_switch); DPORT_REG_SET_FIELD(DPORT_CPU_PER_CONF_REG, DPORT_CPUPERIOD_SEL, 0); SET_PERI_REG_MASK(RTC_CNTL_OPTIONS0_REG, RTC_CNTL_BB_I2C_FORCE_PD | RTC_CNTL_BBPLL_FORCE_PD | RTC_CNTL_BBPLL_I2C_FORCE_PD); s_pll_freq = 0; rtc_clk_apb_freq_update(xtal_freq * MHZ); /* is APLL under force power down? */ uint32_t apll_fpd = REG_GET_FIELD(RTC_CNTL_ANA_CONF_REG, RTC_CNTL_PLLA_FORCE_PD); if (apll_fpd) { /* then also power down the internal I2C bus */ SET_PERI_REG_MASK(RTC_CNTL_OPTIONS0_REG, RTC_CNTL_BIAS_I2C_FORCE_PD); } /* now switch to the desired frequency */ if (cpu_freq == RTC_CPU_FREQ_XTAL) { /* already at XTAL, nothing to do */ } else if (cpu_freq == RTC_CPU_FREQ_2M) { /* set up divider to produce 2MHz from XTAL */ REG_SET_FIELD(APB_CTRL_SYSCLK_CONF_REG, APB_CTRL_PRE_DIV_CNT, (xtal_freq / 2) - 1); ets_update_cpu_frequency(2); rtc_clk_apb_freq_update(2 * MHZ); /* lower the voltage */ REG_SET_FIELD(RTC_CNTL_REG, RTC_CNTL_DIG_DBIAS_WAK, RTC_CNTL_DBIAS_1V00); } else { /* use PLL as clock source */ CLEAR_PERI_REG_MASK(RTC_CNTL_OPTIONS0_REG, RTC_CNTL_BIAS_I2C_FORCE_PD | RTC_CNTL_BB_I2C_FORCE_PD | RTC_CNTL_BBPLL_FORCE_PD | RTC_CNTL_BBPLL_I2C_FORCE_PD); rtc_clk_bbpll_set(xtal_freq, cpu_freq); if (cpu_freq == RTC_CPU_FREQ_80M) { DPORT_REG_SET_FIELD(DPORT_CPU_PER_CONF_REG, DPORT_CPUPERIOD_SEL, 0); ets_update_cpu_frequency(80); s_pll_freq = 320; } else if (cpu_freq == RTC_CPU_FREQ_160M) { DPORT_REG_SET_FIELD(DPORT_CPU_PER_CONF_REG, DPORT_CPUPERIOD_SEL, 1); ets_update_cpu_frequency(160); s_pll_freq = 320; } else if (cpu_freq == RTC_CPU_FREQ_240M) { DPORT_REG_SET_FIELD(DPORT_CPU_PER_CONF_REG, DPORT_CPUPERIOD_SEL, 2); ets_update_cpu_frequency(240); s_pll_freq = 480; } REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL, RTC_CNTL_SOC_CLK_SEL_PLL); ets_delay_us(DELAY_CPU_FREQ_SWITCH_TO_PLL); rtc_clk_apb_freq_update(80 * MHZ); } s_cur_freq = cpu_freq; } rtc_cpu_freq_t rtc_clk_cpu_freq_get() { uint32_t soc_clk_sel = REG_GET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL); switch (soc_clk_sel) { case RTC_CNTL_SOC_CLK_SEL_XTL: { uint32_t pre_div = REG_GET_FIELD(APB_CTRL_SYSCLK_CONF_REG, APB_CTRL_PRE_DIV_CNT); if (pre_div == 0) { return RTC_CPU_FREQ_XTAL; } else if (pre_div == rtc_clk_xtal_freq_get() / 2 - 1) { return RTC_CPU_FREQ_2M; } else { assert(false && "unsupported frequency"); } break; } case RTC_CNTL_SOC_CLK_SEL_PLL: { uint32_t cpuperiod_sel = DPORT_REG_GET_FIELD(DPORT_CPU_PER_CONF_REG, DPORT_CPUPERIOD_SEL); if (cpuperiod_sel == 0) { return RTC_CPU_FREQ_80M; } else if (cpuperiod_sel == 1) { return RTC_CPU_FREQ_160M; } else if (cpuperiod_sel == 2) { return RTC_CPU_FREQ_240M; } else { assert(false && "unsupported frequency"); } break; } case RTC_CNTL_SOC_CLK_SEL_APLL: case RTC_CNTL_SOC_CLK_SEL_8M: default: assert(false && "unsupported frequency"); } return RTC_CNTL_SOC_CLK_SEL_XTL; } uint32_t rtc_clk_cpu_freq_value(rtc_cpu_freq_t cpu_freq) { switch (cpu_freq) { case RTC_CPU_FREQ_XTAL: return ((uint32_t) rtc_clk_xtal_freq_get()) * MHZ; case RTC_CPU_FREQ_2M: return 2 * MHZ; case RTC_CPU_FREQ_80M: return 80 * MHZ; case RTC_CPU_FREQ_160M: return 160 * MHZ; case RTC_CPU_FREQ_240M: return 240 * MHZ; default: assert(false && "invalid rtc_cpu_freq_t value"); return 0; } } /* Values of RTC_XTAL_FREQ_REG and RTC_APB_FREQ_REG are stored as two copies in * lower and upper 16-bit halves. These are the routines to work with such a * representation. */ static bool clk_val_is_valid(uint32_t val) { return (val & 0xffff) == ((val >> 16) & 0xffff) && val != 0 && val != UINT32_MAX; } static uint32_t reg_val_to_clk_val(uint32_t val) { return val & UINT16_MAX; } static uint32_t clk_val_to_reg_val(uint32_t val) { return (val & UINT16_MAX) | ((val & UINT16_MAX) << 16); } rtc_xtal_freq_t rtc_clk_xtal_freq_get() { /* We may have already written XTAL value into RTC_XTAL_FREQ_REG */ uint32_t xtal_freq_reg = READ_PERI_REG(RTC_XTAL_FREQ_REG); if (!clk_val_is_valid(xtal_freq_reg)) { SOC_LOGW(TAG, "invalid RTC_XTAL_FREQ_REG value: 0x%08x", xtal_freq_reg); return RTC_XTAL_FREQ_AUTO; } return reg_val_to_clk_val(xtal_freq_reg); } void rtc_clk_xtal_freq_update(rtc_xtal_freq_t xtal_freq) { WRITE_PERI_REG(RTC_XTAL_FREQ_REG, clk_val_to_reg_val(xtal_freq)); } static rtc_xtal_freq_t rtc_clk_xtal_freq_estimate() { uint64_t cal_val = rtc_clk_cal_ratio(RTC_CAL_8MD256, XTAL_FREQ_EST_CYCLES); /* cal_val contains period of 8M/256 clock in XTAL clock cycles * (shifted by RTC_CLK_CAL_FRACT bits). * Xtal frequency will be (cal_val * 8M / 256) / 2^19 */ uint32_t freq_mhz = (cal_val * (RTC_FAST_CLK_FREQ_APPROX / MHZ) / 256 ) >> RTC_CLK_CAL_FRACT; /* Guess the XTAL type. For now, only 40 and 26MHz are supported. */ switch (freq_mhz) { case 21 ... 31: return RTC_XTAL_FREQ_26M; case 32 ... 33: SOC_LOGW(TAG, "Potentially bogus XTAL frequency: %d MHz, guessing 26 MHz", freq_mhz); return RTC_XTAL_FREQ_26M; case 34 ... 35: SOC_LOGW(TAG, "Potentially bogus XTAL frequency: %d MHz, guessing 40 MHz", freq_mhz); return RTC_XTAL_FREQ_40M; case 36 ... 45: return RTC_XTAL_FREQ_40M; default: SOC_LOGW(TAG, "Bogus XTAL frequency: %d MHz", freq_mhz); return RTC_XTAL_FREQ_AUTO; } } void rtc_clk_apb_freq_update(uint32_t apb_freq) { WRITE_PERI_REG(RTC_APB_FREQ_REG, clk_val_to_reg_val(apb_freq >> 12)); } uint32_t rtc_clk_apb_freq_get() { uint32_t freq_hz = reg_val_to_clk_val(READ_PERI_REG(RTC_APB_FREQ_REG)) << 12; // round to the nearest MHz freq_hz += MHZ / 2; uint32_t remainder = freq_hz % MHZ; return freq_hz - remainder; } void rtc_clk_init(rtc_clk_config_t cfg) { rtc_cpu_freq_t cpu_source_before = rtc_clk_cpu_freq_get(); /* If we get a TG WDT system reset while running at 240MHz, * DPORT_CPUPERIOD_SEL register will be reset to 0 resulting in 120MHz * APB and CPU frequencies after reset. This will cause issues with XTAL * frequency estimation, so we switch to XTAL frequency first. * * Ideally we would only do this if RTC_CNTL_SOC_CLK_SEL == PLL and * PLL is configured for 480M, but it takes less time to switch to 40M and * run the following code than querying the PLL does. */ if (REG_GET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_SOC_CLK_SEL) == RTC_CNTL_SOC_CLK_SEL_PLL) { rtc_clk_cpu_freq_set(RTC_CPU_FREQ_XTAL); } /* Set tuning parameters for 8M and 150k clocks. * Note: this doesn't attempt to set the clocks to precise frequencies. * Instead, we calibrate these clocks against XTAL frequency later, when necessary. * - SCK_DCAP value controls tuning of 150k clock. * The higher the value of DCAP is, the lower is the frequency. * - CK8M_DFREQ value controls tuning of 8M clock. * CLK_8M_DFREQ constant gives the best temperature characteristics. */ REG_SET_FIELD(RTC_CNTL_REG, RTC_CNTL_SCK_DCAP, cfg.slow_clk_dcap); REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_CK8M_DFREQ, cfg.clk_8m_dfreq); /* Configure 8M clock division */ REG_SET_FIELD(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_CK8M_DIV_SEL, cfg.clk_8m_div); /* Enable the internal bus used to configure PLLs */ SET_PERI_REG_BITS(ANA_CONFIG_REG, ANA_CONFIG_M, ANA_CONFIG_M, ANA_CONFIG_S); CLEAR_PERI_REG_MASK(ANA_CONFIG_REG, I2C_APLL_M | I2C_BBPLL_M); /* Estimate XTAL frequency */ rtc_xtal_freq_t est_xtal_freq = rtc_clk_xtal_freq_estimate(); rtc_xtal_freq_t xtal_freq = cfg.xtal_freq; if (xtal_freq == RTC_XTAL_FREQ_AUTO) { if (clk_val_is_valid(READ_PERI_REG(RTC_XTAL_FREQ_REG))) { /* XTAL frequency has already been set, use existing value */ xtal_freq = rtc_clk_xtal_freq_get(); } else { /* Not set yet, estimate XTAL frequency based on RTC_FAST_CLK */ xtal_freq = est_xtal_freq; if (xtal_freq == RTC_XTAL_FREQ_AUTO) { SOC_LOGW(TAG, "Can't estimate XTAL frequency, assuming 26MHz"); xtal_freq = RTC_XTAL_FREQ_26M; } } } else if (!clk_val_is_valid(READ_PERI_REG(RTC_XTAL_FREQ_REG))) { /* Exact frequency was set in sdkconfig, but still warn if autodetected * frequency is different. If autodetection failed, worst case we get a * bit of garbage output. */ SOC_LOGW(TAG, "Possibly invalid CONFIG_ESP32_XTAL_FREQ setting (%dMHz). Detected %d MHz.", xtal_freq, est_xtal_freq); } uart_tx_wait_idle(0); rtc_clk_xtal_freq_update(xtal_freq); rtc_clk_apb_freq_update(xtal_freq * MHZ); /* Set CPU frequency */ rtc_clk_cpu_freq_set(cfg.cpu_freq); /* Re-calculate the ccount to make time calculation correct. */ uint32_t freq_before = rtc_clk_cpu_freq_value(cpu_source_before) / MHZ; uint32_t freq_after = rtc_clk_cpu_freq_value(cfg.cpu_freq) / MHZ; XTHAL_SET_CCOUNT( XTHAL_GET_CCOUNT() * freq_after / freq_before ); /* Slow & fast clocks setup */ if (cfg.slow_freq == RTC_SLOW_FREQ_32K_XTAL) { rtc_clk_32k_enable(true); } if (cfg.fast_freq == RTC_FAST_FREQ_8M) { bool need_8md256 = cfg.slow_freq == RTC_SLOW_FREQ_8MD256; rtc_clk_8m_enable(true, need_8md256); } rtc_clk_fast_freq_set(cfg.fast_freq); rtc_clk_slow_freq_set(cfg.slow_freq); } /* Name used in libphy.a:phy_chip_v7.o * TODO: update the library to use rtc_clk_xtal_freq_get */ rtc_xtal_freq_t rtc_get_xtal() __attribute__((alias("rtc_clk_xtal_freq_get")));