71 lines
2.6 KiB
C
71 lines
2.6 KiB
C
// Copyright 2017 Espressif Systems (Shanghai) PTE LTD
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "rom/uart.h"
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#include "rom/rtc.h"
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#include "soc/soc.h"
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#include "soc/rtc.h"
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#include "soc/dport_reg.h"
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#include "soc/efuse_reg.h"
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#include "soc/rtc_cntl_reg.h"
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void bootloader_clock_configure()
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{
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// ROM bootloader may have put a lot of text into UART0 FIFO.
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// Wait for it to be printed.
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// This is not needed on power on reset, when ROM bootloader is running at
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// 40 MHz. But in case of TG WDT reset, CPU may still be running at >80 MHZ,
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// and will be done with the bootloader much earlier than UART FIFO is empty.
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uart_tx_wait_idle(0);
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/* Set CPU to 80MHz. Keep other clocks unmodified. */
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int cpu_freq_mhz = 80;
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/* On ESP32 rev 0, switching to 80/160 MHz if clock was previously set to
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* 240 MHz may cause the chip to lock up (see section 3.5 of the errata
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* document). For rev. 0, switch to 240 instead if it has been enabled
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* previously.
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*/
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uint32_t chip_ver_reg = REG_READ(EFUSE_BLK0_RDATA3_REG);
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if ((chip_ver_reg & EFUSE_RD_CHIP_VER_REV1_M) == 0 &&
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DPORT_REG_GET_FIELD(DPORT_CPU_PER_CONF_REG, DPORT_CPUPERIOD_SEL) == DPORT_CPUPERIOD_SEL_240) {
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cpu_freq_mhz = 240;
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}
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rtc_clk_config_t clk_cfg = RTC_CLK_CONFIG_DEFAULT();
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clk_cfg.xtal_freq = CONFIG_ESP32_XTAL_FREQ;
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clk_cfg.cpu_freq_mhz = cpu_freq_mhz;
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clk_cfg.slow_freq = rtc_clk_slow_freq_get();
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clk_cfg.fast_freq = rtc_clk_fast_freq_get();
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rtc_clk_init(clk_cfg);
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/* As a slight optimization, if 32k XTAL was enabled in sdkconfig, we enable
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* it here. Usually it needs some time to start up, so we amortize at least
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* part of the start up time by enabling 32k XTAL early.
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* App startup code will wait until the oscillator has started up.
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*/
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#ifdef CONFIG_ESP32_RTC_CLOCK_SOURCE_EXTERNAL_CRYSTAL
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if (!rtc_clk_32k_enabled()) {
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rtc_clk_32k_bootstrap(CONFIG_ESP32_RTC_XTAL_BOOTSTRAP_CYCLES);
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}
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#endif
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}
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#ifdef BOOTLOADER_BUILD
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int esp_clk_apb_freq(void)
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{
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return rtc_clk_apb_freq_get();
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}
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#endif // BOOTLOADER_BUILD
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