422 lines
16 KiB
C
422 lines
16 KiB
C
/*
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* MIT License
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*
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* Copyright (c) 2020 Joey Castillo
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "watch_private.h"
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#include "watch_private_cdc.h"
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#include "watch_utility.h"
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#include "tusb.h"
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void _watch_init(void) {
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// disable the LED pin (it may have been enabled by the bootloader)
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watch_disable_digital_output(GPIO(GPIO_PORTA, 20));
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// disable debugger hot-plugging
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gpio_set_pin_function(SWCLK, GPIO_PIN_FUNCTION_OFF);
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gpio_set_pin_direction(SWCLK, GPIO_DIRECTION_OFF);
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gpio_set_pin_pull_mode(SWCLK, GPIO_PULL_OFF);
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// RAM should be back-biased in STANDBY
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PM->STDBYCFG.bit.BBIASHS = 1;
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// Use switching regulator for lower power consumption.
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SUPC->VREG.bit.SEL = 1;
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// per Microchip datasheet clarification DS80000782,
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// work around silicon erratum 1.7.2, which causes the microcontroller to lock up on leaving standby:
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// request that the voltage regulator run in standby, and also that it switch to PL0.
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SUPC->VREG.bit.RUNSTDBY = 1;
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SUPC->VREG.bit.STDBYPL0 = 1;
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while(!SUPC->STATUS.bit.VREGRDY); // wait for voltage regulator to become ready
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// check the battery voltage...
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watch_enable_adc();
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uint16_t battery_voltage = watch_get_vcc_voltage();
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watch_disable_adc();
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// ...because we can enable the more efficient low power regulator if the system voltage is > 2.5V
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// still, enable LPEFF only if the battery voltage is comfortably above this threshold.
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if (battery_voltage >= 2700) {
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SUPC->VREG.bit.LPEFF = 1;
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} else {
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SUPC->VREG.bit.LPEFF = 0;
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}
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// set up the brownout detector (low battery warning)
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NVIC_DisableIRQ(SYSTEM_IRQn);
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NVIC_ClearPendingIRQ(SYSTEM_IRQn);
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NVIC_EnableIRQ(SYSTEM_IRQn);
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SUPC->BOD33.bit.ENABLE = 0; // BOD33 must be disabled to change its configuration
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SUPC->BOD33.bit.VMON = 0; // Monitor VDD in active and standby mode
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SUPC->BOD33.bit.ACTCFG = 1; // Enable sampling mode when active
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SUPC->BOD33.bit.RUNSTDBY = 1; // Enable sampling mode in standby
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SUPC->BOD33.bit.STDBYCFG = 1; // Run in standby
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SUPC->BOD33.bit.RUNBKUP = 0; // Don't run in backup mode
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SUPC->BOD33.bit.PSEL = 0x9; // Check battery level every second (we'll change this before entering sleep)
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SUPC->BOD33.bit.LEVEL = 34; // Detect brownout at 2.6V (1.445V + level * 34mV)
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SUPC->BOD33.bit.ACTION = 0x2; // Generate an interrupt when BOD33 is triggered
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SUPC->BOD33.bit.HYST = 0; // Disable hysteresis
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while(!SUPC->STATUS.bit.B33SRDY); // wait for BOD33 to sync
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// Enable interrupt on BOD33 detect
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SUPC->INTENSET.bit.BOD33DET = 1;
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SUPC->BOD33.bit.ENABLE = 1;
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// External wake depends on RTC; calendar is a required module.
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_watch_rtc_init();
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// set up state
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btn_alarm_callback = NULL;
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a2_callback = NULL;
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a4_callback = NULL;
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}
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static inline void _watch_wait_for_entropy() {
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while (!TRNG->INTFLAG.bit.DATARDY);
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}
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void watch_disable_TRNG(void) {
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// per Microchip datasheet clarification DS80000782,
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// silicon erratum 1.16.1 indicates that the TRNG may leave internal components powered after being disabled.
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// the workaround is to disable the TRNG by clearing the control register, twice.
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TRNG->CTRLA.bit.ENABLE = 0;
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TRNG->CTRLA.bit.ENABLE = 0;
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}
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// this function is called by arc4random to get entropy for random number generation.
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int getentropy(void *buf, size_t buflen);
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// let's use the SAM L22's true random number generator to seed the PRNG!
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int getentropy(void *buf, size_t buflen) {
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MCLK->APBCMASK.bit.TRNG_ = 1;
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TRNG->CTRLA.bit.ENABLE = 1;
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size_t i = 0;
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while(i < buflen / 4) {
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_watch_wait_for_entropy();
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((uint32_t *)buf)[i++] = TRNG->DATA.reg;
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}
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// but what if they asked for an awkward number of bytes?
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if (buflen % 4) {
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// all good: let's fill in one, two or three bytes at the end of the buffer.
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_watch_wait_for_entropy();
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uint32_t last_little_bit = TRNG->DATA.reg;
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for(size_t j = 0; j <= (buflen % 4); j++) {
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((uint8_t *)buf)[i * 4 + j] = (last_little_bit >> (j * 8)) & 0xFF;
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}
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}
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watch_disable_TRNG();
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MCLK->APBCMASK.bit.TRNG_ = 0;
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return 0;
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}
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void _watch_enable_tc0(void) {
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// before we init TinyUSB, we are going to need a periodic callback to handle TinyUSB tasks.
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// TC2 and TC3 are reserved for devices on the 9-pin connector, so let's use TC0.
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// clock TC0 with the 8 MHz clock on GCLK0.
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hri_gclk_write_PCHCTRL_reg(GCLK, TC0_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK0_Val | GCLK_PCHCTRL_CHEN);
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// and enable the peripheral clock.
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hri_mclk_set_APBCMASK_TC0_bit(MCLK);
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// disable and reset TC0.
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hri_tc_clear_CTRLA_ENABLE_bit(TC0);
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hri_tc_wait_for_sync(TC0, TC_SYNCBUSY_ENABLE);
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hri_tc_write_CTRLA_reg(TC0, TC_CTRLA_SWRST);
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hri_tc_wait_for_sync(TC0, TC_SYNCBUSY_SWRST);
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hri_tc_write_CTRLA_reg(TC0, TC_CTRLA_PRESCALER_DIV1024 | // divide the 8 MHz clock by 1024 to count at 7812.5 Hz
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TC_CTRLA_MODE_COUNT8 | // count in 8-bit mode
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TC_CTRLA_RUNSTDBY); // run in standby, just in case we figure that out
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hri_tccount8_write_PER_reg(TC0, 10); // 7812.5 Hz / 10 = 781.125 Hz
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// set an interrupt on overflow; this will call TC0_Handler below.
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hri_tc_set_INTEN_OVF_bit(TC0);
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// set priority higher than TC1
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NVIC_SetPriority(TC0_IRQn, 5);
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NVIC_ClearPendingIRQ(TC0_IRQn);
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NVIC_EnableIRQ(TC0_IRQn);
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// Start the timer
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hri_tc_set_CTRLA_ENABLE_bit(TC0);
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}
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void _watch_disable_tc0(void) {
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NVIC_DisableIRQ(TC0_IRQn);
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NVIC_ClearPendingIRQ(TC0_IRQn);
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hri_tc_clear_CTRLA_ENABLE_bit(TC0);
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hri_tc_wait_for_sync(TC0, TC_SYNCBUSY_ENABLE);
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hri_tc_write_CTRLA_reg(TC0, TC_CTRLA_SWRST);
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hri_tc_wait_for_sync(TC0, TC_SYNCBUSY_SWRST);
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}
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void _watch_enable_tc1(void) {
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hri_gclk_write_PCHCTRL_reg(GCLK, TC1_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK0_Val | GCLK_PCHCTRL_CHEN);
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// and enable the peripheral clock.
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hri_mclk_set_APBCMASK_TC1_bit(MCLK);
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// disable and reset TC1.
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hri_tc_clear_CTRLA_ENABLE_bit(TC1);
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hri_tc_wait_for_sync(TC1, TC_SYNCBUSY_ENABLE);
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hri_tc_write_CTRLA_reg(TC1, TC_CTRLA_SWRST);
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hri_tc_wait_for_sync(TC1, TC_SYNCBUSY_SWRST);
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hri_tc_write_CTRLA_reg(TC1, TC_CTRLA_PRESCALER_DIV1024 | // divide the 8 MHz clock by 1024 to count at 7812.5 Hz
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TC_CTRLA_MODE_COUNT8 | // count in 8-bit mode
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TC_CTRLA_RUNSTDBY); // run in standby, just in case we figure that out
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hri_tccount8_write_PER_reg(TC1, 20); // 7812.5 Hz / 50 = 156.25 Hz
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// set an interrupt on overflow; this will call TC1_Handler below.
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hri_tc_set_INTEN_OVF_bit(TC1);
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// set priority lower than TC0
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NVIC_SetPriority(TC1_IRQn, 6);
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NVIC_ClearPendingIRQ(TC1_IRQn);
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NVIC_EnableIRQ(TC1_IRQn);
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// Start the timer
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hri_tc_set_CTRLA_ENABLE_bit(TC1);
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}
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void _watch_disable_tc1(void) {
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NVIC_DisableIRQ(TC1_IRQn);
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NVIC_ClearPendingIRQ(TC1_IRQn);
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hri_tc_clear_CTRLA_ENABLE_bit(TC1);
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hri_tc_wait_for_sync(TC1, TC_SYNCBUSY_ENABLE);
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hri_tc_write_CTRLA_reg(TC1, TC_CTRLA_SWRST);
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hri_tc_wait_for_sync(TC1, TC_SYNCBUSY_SWRST);
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}
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void TC0_Handler(void) {
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tud_task();
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TC0->COUNT8.INTFLAG.reg |= TC_INTFLAG_OVF;
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}
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void TC1_Handler(void) {
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cdc_task();
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TC1->COUNT8.INTFLAG.reg |= TC_INTFLAG_OVF;
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}
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void _watch_enable_usb(void) {
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// disable USB, just in case.
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hri_usb_clear_CTRLA_ENABLE_bit(USB);
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// bump clock up to 8 MHz
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hri_oscctrl_write_OSC16MCTRL_FSEL_bf(OSCCTRL, OSCCTRL_OSC16MCTRL_FSEL_8_Val);
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// reset flags and disable DFLL
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OSCCTRL->INTFLAG.reg = OSCCTRL_INTFLAG_DFLLRDY;
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OSCCTRL->DFLLCTRL.reg = 0;
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while (!(OSCCTRL->STATUS.reg & OSCCTRL_STATUS_DFLLRDY));
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// set the coarse and fine values to speed up frequency lock.
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uint32_t coarse =(*((uint32_t *)NVMCTRL_OTP5)) >> 26;
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OSCCTRL->DFLLVAL.reg = OSCCTRL_DFLLVAL_COARSE(coarse) |
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OSCCTRL_DFLLVAL_FINE(0x200);
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// set coarse and fine steps, and multiplier (48 MHz = 32768 Hz * 1465)
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OSCCTRL->DFLLMUL.reg = OSCCTRL_DFLLMUL_CSTEP( 1 ) |
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OSCCTRL_DFLLMUL_FSTEP( 1 ) |
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OSCCTRL_DFLLMUL_MUL( 1465 );
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// set closed loop mode, chill cycle disable and USB clock recovery mode, and enable the DFLL.
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OSCCTRL->DFLLCTRL.reg = OSCCTRL_DFLLCTRL_MODE | OSCCTRL_DFLLCTRL_CCDIS | OSCCTRL_DFLLCTRL_ONDEMAND | OSCCTRL_DFLLCTRL_RUNSTDBY | OSCCTRL_DFLLCTRL_USBCRM | OSCCTRL_DFLLCTRL_ENABLE;
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while (!(OSCCTRL->STATUS.reg & OSCCTRL_STATUS_DFLLRDY));
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// assign DFLL to GCLK1
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GCLK->GENCTRL[1].reg = GCLK_GENCTRL_SRC(GCLK_GENCTRL_SRC_DFLL48M) | GCLK_GENCTRL_DIV(1) | GCLK_GENCTRL_GENEN;// | GCLK_GENCTRL_OE;
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while (GCLK->SYNCBUSY.bit.GENCTRL1); // wait for generator control 1 to sync
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// assign GCLK1 to USB
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hri_gclk_write_PCHCTRL_reg(GCLK, USB_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK1_Val | GCLK_PCHCTRL_CHEN);
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hri_mclk_set_AHBMASK_USB_bit(MCLK);
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hri_mclk_set_APBBMASK_USB_bit(MCLK);
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// USB Pin Init
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gpio_set_pin_direction(PIN_PA24, GPIO_DIRECTION_OUT);
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gpio_set_pin_level(PIN_PA24, false);
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gpio_set_pin_pull_mode(PIN_PA24, GPIO_PULL_OFF);
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gpio_set_pin_direction(PIN_PA25, GPIO_DIRECTION_OUT);
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gpio_set_pin_level(PIN_PA25, false);
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gpio_set_pin_pull_mode(PIN_PA25, GPIO_PULL_OFF);
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gpio_set_pin_function(PIN_PA24, PINMUX_PA24G_USB_DM);
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gpio_set_pin_function(PIN_PA25, PINMUX_PA25G_USB_DP);
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_watch_enable_tc0();
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tusb_init();
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_watch_enable_tc1();
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}
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void USB_Handler(void) {
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tud_int_handler(0);
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}
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// USB Descriptors and tinyUSB callbacks follow.
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/*
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* The MIT License (MIT)
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*
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* Copyright (c) 2019 Ha Thach (tinyusb.org)
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*
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*/
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//--------------------------------------------------------------------+
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// Device Descriptors
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//--------------------------------------------------------------------+
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tusb_desc_device_t const desc_device =
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{
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.bLength = sizeof(tusb_desc_device_t),
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.bDescriptorType = TUSB_DESC_DEVICE,
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.bcdUSB = 0x0200,
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// Use Interface Association Descriptor (IAD) for CDC
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// As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
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.bDeviceClass = TUSB_CLASS_MISC,
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.bDeviceSubClass = MISC_SUBCLASS_COMMON,
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.bDeviceProtocol = MISC_PROTOCOL_IAD,
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.bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,
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.idVendor = 0x1209,
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.idProduct = 0x2151,
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.bcdDevice = 0x0100,
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.iManufacturer = 0x01,
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.iProduct = 0x02,
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.iSerialNumber = 0x03,
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.bNumConfigurations = 0x01
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};
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// Invoked when received GET DEVICE DESCRIPTOR
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// Application return pointer to descriptor
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uint8_t const * tud_descriptor_device_cb(void) {
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return (uint8_t const *) &desc_device;
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}
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//--------------------------------------------------------------------+
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// Configuration Descriptor
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//--------------------------------------------------------------------+
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enum {
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ITF_NUM_CDC = 0,
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ITF_NUM_CDC_DATA,
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ITF_NUM_TOTAL
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};
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#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN)
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#define EPNUM_CDC_NOTIF 0x81
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#define EPNUM_CDC_OUT 0x02
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#define EPNUM_CDC_IN 0x82
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uint8_t const desc_fs_configuration[] = {
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// Config number, interface count, string index, total length, attribute, power in mA
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TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
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// Interface number, string index, EP notification address and size, EP data address (out, in) and size.
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TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
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};
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// Invoked when received GET CONFIGURATION DESCRIPTOR
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// Application return pointer to descriptor
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// Descriptor contents must exist long enough for transfer to complete
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uint8_t const * tud_descriptor_configuration_cb(uint8_t index) {
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(void) index; // for multiple configurations
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return desc_fs_configuration;
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}
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//--------------------------------------------------------------------+
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// String Descriptors
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//--------------------------------------------------------------------+
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// array of pointer to string descriptors
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char const* string_desc_arr [] =
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{
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(const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
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"TinyUSB", // 1: Manufacturer
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"TinyUSB Device", // 2: Product
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"123456", // 3: Serials, should use chip ID
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"TinyUSB CDC", // 4: CDC Interface
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};
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static uint16_t _desc_str[32];
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// Invoked when received GET STRING DESCRIPTOR request
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// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
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uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
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{
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(void) langid;
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uint8_t chr_count;
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if ( index == 0) {
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memcpy(&_desc_str[1], string_desc_arr[0], 2);
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chr_count = 1;
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} else {
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// Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
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// https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
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if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
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const char* str = string_desc_arr[index];
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// Cap at max char
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chr_count = strlen(str);
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if ( chr_count > 31 ) chr_count = 31;
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// Convert ASCII string into UTF-16
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for(uint8_t i=0; i<chr_count; i++)
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{
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_desc_str[1+i] = str[i];
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}
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}
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// first byte is length (including header), second byte is string type
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_desc_str[0] = (TUSB_DESC_STRING << 8 ) | (2*chr_count + 2);
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return _desc_str;
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}
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void watch_reset_to_bootloader(void) {
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volatile uint32_t *dbl_tap_ptr = ((volatile uint32_t *)(HSRAM_ADDR + HSRAM_SIZE - 4));
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*dbl_tap_ptr = 0xf01669ef; // from the UF2 bootloaer: uf2.h line 255
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NVIC_SystemReset();
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}
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