Sergey Solodunov
mbed library sources. Supersedes mbed-src.
Fork of
mbed-dev
by 
mbed official
Diff: targets/hal/TARGET_Atmel/TARGET_SAM_CortexM0P/drivers/system/clock/TARGET_SAMR21/clock.c
- Revision:
- 18:da299f395b9e
- Parent:
- 15:a81a8d6c1dfe
- Child:
- 64:41a834223ea3
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Atmel/TARGET_SAM_CortexM0P/drivers/system/clock/TARGET_SAMR21/clock.c Mon Nov 09 13:30:11 2015 +0000
@@ -0,0 +1,1031 @@
+/**
+ * \file
+ *
+ * \brief SAM D21/R21/DA0/DA1 Clock Driver
+ *
+ * Copyright (C) 2013-2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ * Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+/*
+ * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
+ */
+#include <clock.h>
+#include <conf_clocks.h>
+#include <system.h>
+
+#ifndef SYSCTRL_FUSES_OSC32K_ADDR
+#if (SAMR21) || (SAMD)
+# define SYSCTRL_FUSES_OSC32K_ADDR FUSES_OSC32K_CAL_ADDR
+# define SYSCTRL_FUSES_OSC32K_Pos FUSES_OSC32K_CAL_Pos
+#elif (SAML21)
+# define SYSCTRL_FUSES_OSC32K_ADDR NVMCTRL_OTP4
+# define SYSCTRL_FUSES_OSC32K_Pos 6
+
+#else
+# define SYSCTRL_FUSES_OSC32K_ADDR SYSCTRL_FUSES_OSC32K_CAL_ADDR
+# define SYSCTRL_FUSES_OSC32K_Pos SYSCTRL_FUSES_OSC32K_CAL_Pos
+#endif
+#endif
+
+/**
+ * \internal
+ * \brief DFLL-specific data container.
+ */
+struct _system_clock_dfll_config {
+ uint32_t control;
+ uint32_t val;
+ uint32_t mul;
+};
+
+/**
+ * \internal
+ * \brief DPLL-specific data container.
+ */
+struct _system_clock_dpll_config {
+ uint32_t frequency;
+};
+
+
+/**
+ * \internal
+ * \brief XOSC-specific data container.
+ */
+struct _system_clock_xosc_config {
+ uint32_t frequency;
+};
+
+/**
+ * \internal
+ * \brief System clock module data container.
+ */
+struct _system_clock_module {
+ volatile struct _system_clock_dfll_config dfll;
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+ volatile struct _system_clock_dpll_config dpll;
+#endif
+
+ volatile struct _system_clock_xosc_config xosc;
+ volatile struct _system_clock_xosc_config xosc32k;
+};
+
+/**
+ * \internal
+ * \brief Internal module instance to cache configuration values.
+ */
+static struct _system_clock_module _system_clock_inst = {
+ .dfll = {
+ .control = 0,
+ .val = 0,
+ .mul = 0,
+ },
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+ .dpll = {
+ .frequency = 0,
+ },
+#endif
+ .xosc = {
+ .frequency = 0,
+ },
+ .xosc32k = {
+ .frequency = 0,
+ },
+};
+
+/**
+ * \internal
+ * \brief Wait for sync to the DFLL control registers.
+ */
+static inline void _system_dfll_wait_for_sync(void)
+{
+ while (!(SYSCTRL->PCLKSR.reg & SYSCTRL_PCLKSR_DFLLRDY)) {
+ /* Wait for DFLL sync */
+ }
+}
+
+/**
+ * \internal
+ * \brief Wait for sync to the OSC32K control registers.
+ */
+static inline void _system_osc32k_wait_for_sync(void)
+{
+ while (!(SYSCTRL->PCLKSR.reg & SYSCTRL_PCLKSR_OSC32KRDY)) {
+ /* Wait for OSC32K sync */
+ }
+}
+
+static inline void _system_clock_source_dfll_set_config_errata_9905(void)
+{
+
+ /* Disable ONDEMAND mode while writing configurations */
+ SYSCTRL->DFLLCTRL.reg = _system_clock_inst.dfll.control & ~SYSCTRL_DFLLCTRL_ONDEMAND;
+ _system_dfll_wait_for_sync();
+
+ SYSCTRL->DFLLMUL.reg = _system_clock_inst.dfll.mul;
+ SYSCTRL->DFLLVAL.reg = _system_clock_inst.dfll.val;
+
+ /* Write full configuration to DFLL control register */
+ SYSCTRL->DFLLCTRL.reg = _system_clock_inst.dfll.control;
+}
+
+/**
+ * \brief Retrieve the frequency of a clock source.
+ *
+ * Determines the current operating frequency of a given clock source.
+ *
+ * \param[in] clock_source Clock source to get the frequency
+ *
+ * \returns Frequency of the given clock source, in Hz.
+ */
+uint32_t system_clock_source_get_hz(
+ const enum system_clock_source clock_source)
+{
+ switch (clock_source) {
+ case SYSTEM_CLOCK_SOURCE_XOSC:
+ return _system_clock_inst.xosc.frequency;
+
+ case SYSTEM_CLOCK_SOURCE_OSC8M:
+ return 8000000UL >> SYSCTRL->OSC8M.bit.PRESC;
+
+ case SYSTEM_CLOCK_SOURCE_OSC32K:
+ return 32768UL;
+
+ case SYSTEM_CLOCK_SOURCE_ULP32K:
+ return 32768UL;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC32K:
+ return _system_clock_inst.xosc32k.frequency;
+
+ case SYSTEM_CLOCK_SOURCE_DFLL:
+
+ /* Check if the DFLL has been configured */
+ if (!(_system_clock_inst.dfll.control & SYSCTRL_DFLLCTRL_ENABLE))
+ return 0;
+
+ /* Make sure that the DFLL module is ready */
+ _system_dfll_wait_for_sync();
+
+ /* Check if operating in closed loop mode */
+ if (_system_clock_inst.dfll.control & SYSCTRL_DFLLCTRL_MODE) {
+ return system_gclk_chan_get_hz(SYSCTRL_GCLK_ID_DFLL48) *
+ (_system_clock_inst.dfll.mul & 0xffff);
+ }
+
+ return 48000000UL;
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+ case SYSTEM_CLOCK_SOURCE_DPLL:
+ if (!(SYSCTRL->DPLLSTATUS.reg & SYSCTRL_DPLLSTATUS_ENABLE)) {
+ return 0;
+ }
+
+ return _system_clock_inst.dpll.frequency;
+#endif
+
+ default:
+ return 0;
+ }
+}
+
+/**
+ * \brief Configure the internal OSC8M oscillator clock source.
+ *
+ * Configures the 8MHz (nominal) internal RC oscillator with the given
+ * configuration settings.
+ *
+ * \param[in] config OSC8M configuration structure containing the new config
+ */
+void system_clock_source_osc8m_set_config(
+ struct system_clock_source_osc8m_config *const config)
+{
+ SYSCTRL_OSC8M_Type temp = SYSCTRL->OSC8M;
+
+ /* Use temporary struct to reduce register access */
+ temp.bit.PRESC = config->prescaler;
+ temp.bit.ONDEMAND = config->on_demand;
+ temp.bit.RUNSTDBY = config->run_in_standby;
+
+ SYSCTRL->OSC8M = temp;
+}
+
+/**
+ * \brief Configure the internal OSC32K oscillator clock source.
+ *
+ * Configures the 32KHz (nominal) internal RC oscillator with the given
+ * configuration settings.
+ *
+ * \param[in] config OSC32K configuration structure containing the new config
+ */
+void system_clock_source_osc32k_set_config(
+ struct system_clock_source_osc32k_config *const config)
+{
+ SYSCTRL_OSC32K_Type temp = SYSCTRL->OSC32K;
+
+ /* Update settings via a temporary struct to reduce register access */
+ temp.bit.EN1K = config->enable_1khz_output;
+ temp.bit.EN32K = config->enable_32khz_output;
+ temp.bit.STARTUP = config->startup_time;
+ temp.bit.ONDEMAND = config->on_demand;
+ temp.bit.RUNSTDBY = config->run_in_standby;
+ temp.bit.WRTLOCK = config->write_once;
+
+ SYSCTRL->OSC32K = temp;
+}
+
+/**
+ * \brief Configure the external oscillator clock source.
+ *
+ * Configures the external oscillator clock source with the given configuration
+ * settings.
+ *
+ * \param[in] config External oscillator configuration structure containing
+ * the new config
+ */
+void system_clock_source_xosc_set_config(
+ struct system_clock_source_xosc_config *const config)
+{
+ SYSCTRL_XOSC_Type temp = SYSCTRL->XOSC;
+
+ temp.bit.STARTUP = config->startup_time;
+
+ if (config->external_clock == SYSTEM_CLOCK_EXTERNAL_CRYSTAL) {
+ temp.bit.XTALEN = 1;
+ } else {
+ temp.bit.XTALEN = 0;
+ }
+
+ temp.bit.AMPGC = config->auto_gain_control;
+
+ /* Set gain if automatic gain control is not selected */
+ if (!config->auto_gain_control) {
+ if (config->frequency <= 2000000) {
+ temp.bit.GAIN = 0;
+ } else if (config->frequency <= 4000000) {
+ temp.bit.GAIN = 1;
+ } else if (config->frequency <= 8000000) {
+ temp.bit.GAIN = 2;
+ } else if (config->frequency <= 16000000) {
+ temp.bit.GAIN = 3;
+ } else if (config->frequency <= 30000000) {
+ temp.bit.GAIN = 4;
+ }
+
+ }
+
+ temp.bit.ONDEMAND = config->on_demand;
+ temp.bit.RUNSTDBY = config->run_in_standby;
+
+ /* Store XOSC frequency for internal use */
+ _system_clock_inst.xosc.frequency = config->frequency;
+
+ SYSCTRL->XOSC = temp;
+}
+
+/**
+ * \brief Configure the XOSC32K external 32KHz oscillator clock source.
+ *
+ * Configures the external 32KHz oscillator clock source with the given
+ * configuration settings.
+ *
+ * \param[in] config XOSC32K configuration structure containing the new config
+ */
+void system_clock_source_xosc32k_set_config(
+ struct system_clock_source_xosc32k_config *const config)
+{
+ SYSCTRL_XOSC32K_Type temp = SYSCTRL->XOSC32K;
+
+ temp.bit.STARTUP = config->startup_time;
+
+ if (config->external_clock == SYSTEM_CLOCK_EXTERNAL_CRYSTAL) {
+ temp.bit.XTALEN = 1;
+ } else {
+ temp.bit.XTALEN = 0;
+ }
+
+ temp.bit.AAMPEN = config->auto_gain_control;
+ temp.bit.EN1K = config->enable_1khz_output;
+ temp.bit.EN32K = config->enable_32khz_output;
+
+ temp.bit.ONDEMAND = config->on_demand;
+ temp.bit.RUNSTDBY = config->run_in_standby;
+ temp.bit.WRTLOCK = config->write_once;
+
+ /* Cache the new frequency in case the user needs to check the current
+ * operating frequency later */
+ _system_clock_inst.xosc32k.frequency = config->frequency;
+
+ SYSCTRL->XOSC32K = temp;
+}
+
+/**
+ * \brief Configure the DFLL clock source.
+ *
+ * Configures the Digital Frequency Locked Loop clock source with the given
+ * configuration settings.
+ *
+ * \note The DFLL will be running when this function returns, as the DFLL module
+ * needs to be enabled in order to perform the module configuration.
+ *
+ * \param[in] config DFLL configuration structure containing the new config
+ */
+void system_clock_source_dfll_set_config(
+ struct system_clock_source_dfll_config *const config)
+{
+ _system_clock_inst.dfll.val =
+ SYSCTRL_DFLLVAL_COARSE(config->coarse_value) |
+ SYSCTRL_DFLLVAL_FINE(config->fine_value);
+
+ _system_clock_inst.dfll.control =
+ (uint32_t)config->wakeup_lock |
+ (uint32_t)config->stable_tracking |
+ (uint32_t)config->quick_lock |
+ (uint32_t)config->chill_cycle |
+ ((uint32_t)config->on_demand << SYSCTRL_DFLLCTRL_ONDEMAND_Pos);
+
+ if (config->loop_mode == SYSTEM_CLOCK_DFLL_LOOP_MODE_CLOSED) {
+
+ _system_clock_inst.dfll.mul =
+ SYSCTRL_DFLLMUL_CSTEP(config->coarse_max_step) |
+ SYSCTRL_DFLLMUL_FSTEP(config->fine_max_step) |
+ SYSCTRL_DFLLMUL_MUL(config->multiply_factor);
+
+ /* Enable the closed loop mode */
+ _system_clock_inst.dfll.control |= config->loop_mode;
+ }
+ if (config->loop_mode == SYSTEM_CLOCK_DFLL_LOOP_MODE_USB_RECOVERY) {
+
+ _system_clock_inst.dfll.mul =
+ SYSCTRL_DFLLMUL_MUL(config->multiply_factor);
+
+ /* Enable the USB recovery mode */
+ _system_clock_inst.dfll.control |= config->loop_mode |
+ SYSCTRL_DFLLCTRL_BPLCKC;
+ }
+}
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+/**
+ * \brief Configure the DPLL clock source.
+ *
+ * Configures the Digital Phase-Locked Loop clock source with the given
+ * configuration settings.
+ *
+ * \note The DPLL will be running when this function returns, as the DPLL module
+ * needs to be enabled in order to perform the module configuration.
+ *
+ * \param[in] config DPLL configuration structure containing the new config
+ */
+void system_clock_source_dpll_set_config(
+ struct system_clock_source_dpll_config *const config)
+{
+
+ uint32_t tmpldr;
+ uint8_t tmpldrfrac;
+ uint32_t refclk;
+
+ refclk = config->reference_frequency;
+
+ /* Only reference clock REF1 can be divided */
+ if (config->reference_clock == SYSTEM_CLOCK_SOURCE_DPLL_REFERENCE_CLOCK_XOSC) {
+ refclk = refclk / (2 * (config->reference_divider + 1));
+ }
+
+ /* Calculate LDRFRAC and LDR */
+ tmpldr = (config->output_frequency << 4) / refclk;
+ tmpldrfrac = tmpldr & 0x0f;
+ tmpldr = (tmpldr >> 4) - 1;
+
+ SYSCTRL->DPLLCTRLA.reg =
+ ((uint32_t)config->on_demand << SYSCTRL_DPLLCTRLA_ONDEMAND_Pos) |
+ ((uint32_t)config->run_in_standby << SYSCTRL_DPLLCTRLA_RUNSTDBY_Pos);
+
+ SYSCTRL->DPLLRATIO.reg =
+ SYSCTRL_DPLLRATIO_LDRFRAC(tmpldrfrac) |
+ SYSCTRL_DPLLRATIO_LDR(tmpldr);
+
+ SYSCTRL->DPLLCTRLB.reg =
+ SYSCTRL_DPLLCTRLB_DIV(config->reference_divider) |
+ ((uint32_t)config->lock_bypass << SYSCTRL_DPLLCTRLB_LBYPASS_Pos) |
+ SYSCTRL_DPLLCTRLB_LTIME(config->lock_time) |
+ SYSCTRL_DPLLCTRLB_REFCLK(config->reference_clock) |
+ ((uint32_t)config->wake_up_fast << SYSCTRL_DPLLCTRLB_WUF_Pos) |
+ ((uint32_t)config->low_power_enable << SYSCTRL_DPLLCTRLB_LPEN_Pos) |
+ SYSCTRL_DPLLCTRLB_FILTER(config->filter);
+
+ /*
+ * Fck = Fckrx * (LDR + 1 + LDRFRAC / 16)
+ */
+ _system_clock_inst.dpll.frequency =
+ (refclk * (((tmpldr + 1) << 4) + tmpldrfrac)) >> 4;
+}
+#endif
+
+/**
+ * \brief Writes the calibration values for a given oscillator clock source.
+ *
+ * Writes an oscillator calibration value to the given oscillator control
+ * registers. The acceptable ranges are:
+ *
+ * For OSC32K:
+ * - 7 bits (max value 128)
+ * For OSC8MHZ:
+ * - 8 bits (Max value 255)
+ * For OSCULP:
+ * - 5 bits (Max value 32)
+ *
+ * \note The frequency range parameter applies only when configuring the 8MHz
+ * oscillator and will be ignored for the other oscillators.
+ *
+ * \param[in] clock_source Clock source to calibrate
+ * \param[in] calibration_value Calibration value to write
+ * \param[in] freq_range Frequency range (8MHz oscillator only)
+ *
+ * \retval STATUS_OK The calibration value was written
+ * successfully.
+ * \retval STATUS_ERR_INVALID_ARG The setting is not valid for selected clock
+ * source.
+ */
+enum status_code system_clock_source_write_calibration(
+ const enum system_clock_source clock_source,
+ const uint16_t calibration_value,
+ const uint8_t freq_range)
+{
+ switch (clock_source) {
+ case SYSTEM_CLOCK_SOURCE_OSC8M:
+
+ if (calibration_value > 0xfff || freq_range > 4) {
+ return STATUS_ERR_INVALID_ARG;
+ }
+
+ SYSCTRL->OSC8M.bit.CALIB = calibration_value;
+ SYSCTRL->OSC8M.bit.FRANGE = freq_range;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_OSC32K:
+
+ if (calibration_value > 128) {
+ return STATUS_ERR_INVALID_ARG;
+ }
+
+ _system_osc32k_wait_for_sync();
+ SYSCTRL->OSC32K.bit.CALIB = calibration_value;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_ULP32K:
+
+ if (calibration_value > 32) {
+ return STATUS_ERR_INVALID_ARG;
+ }
+
+ SYSCTRL->OSCULP32K.bit.CALIB = calibration_value;
+ break;
+
+ default:
+ Assert(false);
+ return STATUS_ERR_INVALID_ARG;
+ break;
+ }
+
+ return STATUS_OK;
+}
+
+/**
+ * \brief Enables a clock source.
+ *
+ * Enables a clock source which has been previously configured.
+ *
+ * \param[in] clock_source Clock source to enable
+ *
+ * \retval STATUS_OK Clock source was enabled successfully and
+ * is ready
+ * \retval STATUS_ERR_INVALID_ARG The clock source is not available on this
+ * device
+ */
+enum status_code system_clock_source_enable(
+ const enum system_clock_source clock_source)
+{
+ switch (clock_source) {
+ case SYSTEM_CLOCK_SOURCE_OSC8M:
+ SYSCTRL->OSC8M.reg |= SYSCTRL_OSC8M_ENABLE;
+ return STATUS_OK;
+
+ case SYSTEM_CLOCK_SOURCE_OSC32K:
+ SYSCTRL->OSC32K.reg |= SYSCTRL_OSC32K_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC:
+ SYSCTRL->XOSC.reg |= SYSCTRL_XOSC_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC32K:
+ SYSCTRL->XOSC32K.reg |= SYSCTRL_XOSC32K_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_DFLL:
+ _system_clock_inst.dfll.control |= SYSCTRL_DFLLCTRL_ENABLE;
+ _system_clock_source_dfll_set_config_errata_9905();
+ break;
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+ case SYSTEM_CLOCK_SOURCE_DPLL:
+ SYSCTRL->DPLLCTRLA.reg |= SYSCTRL_DPLLCTRLA_ENABLE;
+ break;
+#endif
+
+ case SYSTEM_CLOCK_SOURCE_ULP32K:
+ /* Always enabled */
+ return STATUS_OK;
+
+ default:
+ Assert(false);
+ return STATUS_ERR_INVALID_ARG;
+ }
+
+ return STATUS_OK;
+ }
+
+ /**
+ * \brief Disables a clock source.
+ *
+ * Disables a clock source that was previously enabled.
+ *
+ * \param[in] clock_source Clock source to disable
+ *
+ * \retval STATUS_OK Clock source was disabled successfully
+ * \retval STATUS_ERR_INVALID_ARG An invalid or unavailable clock source was
+ * given
+ */
+ enum status_code system_clock_source_disable(
+ const enum system_clock_source clock_source)
+{
+ switch (clock_source) {
+ case SYSTEM_CLOCK_SOURCE_OSC8M:
+ SYSCTRL->OSC8M.reg &= ~SYSCTRL_OSC8M_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_OSC32K:
+ SYSCTRL->OSC32K.reg &= ~SYSCTRL_OSC32K_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC:
+ SYSCTRL->XOSC.reg &= ~SYSCTRL_XOSC_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC32K:
+ SYSCTRL->XOSC32K.reg &= ~SYSCTRL_XOSC32K_ENABLE;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_DFLL:
+ _system_clock_inst.dfll.control &= ~SYSCTRL_DFLLCTRL_ENABLE;
+ SYSCTRL->DFLLCTRL.reg = _system_clock_inst.dfll.control;
+ break;
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+ case SYSTEM_CLOCK_SOURCE_DPLL:
+ SYSCTRL->DPLLCTRLA.reg &= ~SYSCTRL_DPLLCTRLA_ENABLE;
+ break;
+#endif
+
+ case SYSTEM_CLOCK_SOURCE_ULP32K:
+ /* Not possible to disable */
+
+ default:
+ Assert(false);
+ return STATUS_ERR_INVALID_ARG;
+
+ }
+
+ return STATUS_OK;
+ }
+
+ /**
+ * \brief Checks if a clock source is ready.
+ *
+ * Checks if a given clock source is ready to be used.
+ *
+ * \param[in] clock_source Clock source to check if ready
+ *
+ * \returns Ready state of the given clock source.
+ *
+ * \retval true Clock source is enabled and ready
+ * \retval false Clock source is disabled or not yet ready
+ */
+ bool system_clock_source_is_ready(
+ const enum system_clock_source clock_source)
+{
+ uint32_t mask = 0;
+
+ switch (clock_source) {
+ case SYSTEM_CLOCK_SOURCE_OSC8M:
+ mask = SYSCTRL_PCLKSR_OSC8MRDY;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_OSC32K:
+ mask = SYSCTRL_PCLKSR_OSC32KRDY;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC:
+ mask = SYSCTRL_PCLKSR_XOSCRDY;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_XOSC32K:
+ mask = SYSCTRL_PCLKSR_XOSC32KRDY;
+ break;
+
+ case SYSTEM_CLOCK_SOURCE_DFLL:
+ if (CONF_CLOCK_DFLL_LOOP_MODE == SYSTEM_CLOCK_DFLL_LOOP_MODE_CLOSED) {
+ mask = (SYSCTRL_PCLKSR_DFLLRDY |
+ SYSCTRL_PCLKSR_DFLLLCKF | SYSCTRL_PCLKSR_DFLLLCKC);
+ } else {
+ mask = SYSCTRL_PCLKSR_DFLLRDY;
+ }
+ break;
+
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+ case SYSTEM_CLOCK_SOURCE_DPLL:
+ return ((SYSCTRL->DPLLSTATUS.reg &
+ (SYSCTRL_DPLLSTATUS_CLKRDY | SYSCTRL_DPLLSTATUS_LOCK)) ==
+ (SYSCTRL_DPLLSTATUS_CLKRDY | SYSCTRL_DPLLSTATUS_LOCK));
+#endif
+
+ case SYSTEM_CLOCK_SOURCE_ULP32K:
+ /* Not possible to disable */
+ return true;
+
+ default:
+ return false;
+ }
+
+ return ((SYSCTRL->PCLKSR.reg & mask) == mask);
+}
+
+/* Include some checks for conf_clocks.h validation */
+#include "clock_config_check.h"
+
+#if !defined(__DOXYGEN__)
+/** \internal
+ *
+ * Configures a Generic Clock Generator with the configuration from \c conf_clocks.h.
+ */
+# define _CONF_CLOCK_GCLK_CONFIG(n, unused) \
+ if (CONF_CLOCK_GCLK_##n##_ENABLE == true) { \
+ struct system_gclk_gen_config gclk_conf; \
+ system_gclk_gen_get_config_defaults(&gclk_conf); \
+ gclk_conf.source_clock = CONF_CLOCK_GCLK_##n##_CLOCK_SOURCE; \
+ gclk_conf.division_factor = CONF_CLOCK_GCLK_##n##_PRESCALER; \
+ gclk_conf.run_in_standby = CONF_CLOCK_GCLK_##n##_RUN_IN_STANDBY; \
+ gclk_conf.output_enable = CONF_CLOCK_GCLK_##n##_OUTPUT_ENABLE; \
+ system_gclk_gen_set_config(GCLK_GENERATOR_##n, &gclk_conf); \
+ system_gclk_gen_enable(GCLK_GENERATOR_##n); \
+ }
+
+/** \internal
+ *
+ * Configures a Generic Clock Generator with the configuration from \c conf_clocks.h,
+ * provided that it is not the main Generic Clock Generator channel.
+ */
+# define _CONF_CLOCK_GCLK_CONFIG_NONMAIN(n, unused) \
+ if (n > 0) { _CONF_CLOCK_GCLK_CONFIG(n, unused); }
+#endif
+
+/** \internal
+ *
+ * Switch all peripheral clock to a not enabled general clock
+ * to save power.
+ */
+static void _switch_peripheral_gclk(void)
+{
+ uint32_t gclk_id;
+ struct system_gclk_chan_config gclk_conf;
+
+#if CONF_CLOCK_GCLK_1_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_1;
+#elif CONF_CLOCK_GCLK_2_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_2;
+#elif CONF_CLOCK_GCLK_3_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_3;
+#elif CONF_CLOCK_GCLK_4_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_4;
+#elif CONF_CLOCK_GCLK_5_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_5;
+#elif CONF_CLOCK_GCLK_6_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_6;
+#elif CONF_CLOCK_GCLK_7_ENABLE == false
+ gclk_conf.source_generator = GCLK_GENERATOR_7;
+#else
+ gclk_conf.source_generator = GCLK_GENERATOR_7;
+#endif
+
+ for (gclk_id = 0; gclk_id < GCLK_NUM; gclk_id++) {
+ system_gclk_chan_set_config(gclk_id, &gclk_conf);
+ }
+}
+
+/**
+ * \brief Initialize clock system based on the configuration in conf_clocks.h.
+ *
+ * This function will apply the settings in conf_clocks.h when run from the user
+ * application. All clock sources and GCLK generators are running when this function
+ * returns.
+ *
+ * \note OSC8M is always enabled and if user selects other clocks for GCLK generators,
+ * the OSC8M default enable can be disabled after system_clock_init. Make sure the
+ * clock switch successfully before disabling OSC8M.
+ */
+void system_clock_init(void)
+{
+ /* Various bits in the INTFLAG register can be set to one at startup.
+ This will ensure that these bits are cleared */
+ SYSCTRL->INTFLAG.reg = SYSCTRL_INTFLAG_BOD33RDY | SYSCTRL_INTFLAG_BOD33DET |
+ SYSCTRL_INTFLAG_DFLLRDY;
+
+ system_flash_set_waitstates(CONF_CLOCK_FLASH_WAIT_STATES);
+
+ /* Switch all peripheral clock to a not enabled general clock to save power. */
+ _switch_peripheral_gclk();
+
+ /* XOSC */
+#if CONF_CLOCK_XOSC_ENABLE == true
+ struct system_clock_source_xosc_config xosc_conf;
+ system_clock_source_xosc_get_config_defaults(&xosc_conf);
+
+ xosc_conf.external_clock = CONF_CLOCK_XOSC_EXTERNAL_CRYSTAL;
+ xosc_conf.startup_time = CONF_CLOCK_XOSC_STARTUP_TIME;
+ xosc_conf.auto_gain_control = CONF_CLOCK_XOSC_AUTO_GAIN_CONTROL;
+ xosc_conf.frequency = CONF_CLOCK_XOSC_EXTERNAL_FREQUENCY;
+ xosc_conf.on_demand = CONF_CLOCK_XOSC_ON_DEMAND;
+ xosc_conf.run_in_standby = CONF_CLOCK_XOSC_RUN_IN_STANDBY;
+
+ system_clock_source_xosc_set_config(&xosc_conf);
+ system_clock_source_enable(SYSTEM_CLOCK_SOURCE_XOSC);
+#endif
+
+
+ /* XOSC32K */
+#if CONF_CLOCK_XOSC32K_ENABLE == true
+ struct system_clock_source_xosc32k_config xosc32k_conf;
+ system_clock_source_xosc32k_get_config_defaults(&xosc32k_conf);
+
+ xosc32k_conf.frequency = 32768UL;
+ xosc32k_conf.external_clock = CONF_CLOCK_XOSC32K_EXTERNAL_CRYSTAL;
+ xosc32k_conf.startup_time = CONF_CLOCK_XOSC32K_STARTUP_TIME;
+ xosc32k_conf.auto_gain_control = CONF_CLOCK_XOSC32K_AUTO_AMPLITUDE_CONTROL;
+ xosc32k_conf.enable_1khz_output = CONF_CLOCK_XOSC32K_ENABLE_1KHZ_OUPUT;
+ xosc32k_conf.enable_32khz_output = CONF_CLOCK_XOSC32K_ENABLE_32KHZ_OUTPUT;
+ xosc32k_conf.on_demand = false;
+ xosc32k_conf.run_in_standby = CONF_CLOCK_XOSC32K_RUN_IN_STANDBY;
+
+ system_clock_source_xosc32k_set_config(&xosc32k_conf);
+ system_clock_source_enable(SYSTEM_CLOCK_SOURCE_XOSC32K);
+ while(!system_clock_source_is_ready(SYSTEM_CLOCK_SOURCE_XOSC32K));
+ if (CONF_CLOCK_XOSC32K_ON_DEMAND) {
+ SYSCTRL->XOSC32K.bit.ONDEMAND = 1;
+ }
+#endif
+
+
+ /* OSCK32K */
+#if CONF_CLOCK_OSC32K_ENABLE == true
+ SYSCTRL->OSC32K.bit.CALIB =
+ ((*(uint32_t *)SYSCTRL_FUSES_OSC32K_ADDR >>
+ SYSCTRL_FUSES_OSC32K_Pos) & 0x7Ful);
+
+ struct system_clock_source_osc32k_config osc32k_conf;
+ system_clock_source_osc32k_get_config_defaults(&osc32k_conf);
+
+ osc32k_conf.startup_time = CONF_CLOCK_OSC32K_STARTUP_TIME;
+ osc32k_conf.enable_1khz_output = CONF_CLOCK_OSC32K_ENABLE_1KHZ_OUTPUT;
+ osc32k_conf.enable_32khz_output = CONF_CLOCK_OSC32K_ENABLE_32KHZ_OUTPUT;
+ osc32k_conf.on_demand = CONF_CLOCK_OSC32K_ON_DEMAND;
+ osc32k_conf.run_in_standby = CONF_CLOCK_OSC32K_RUN_IN_STANDBY;
+
+ system_clock_source_osc32k_set_config(&osc32k_conf);
+ system_clock_source_enable(SYSTEM_CLOCK_SOURCE_OSC32K);
+#endif
+
+
+ /* DFLL Config (Open and Closed Loop) */
+#if CONF_CLOCK_DFLL_ENABLE == true
+ struct system_clock_source_dfll_config dfll_conf;
+ system_clock_source_dfll_get_config_defaults(&dfll_conf);
+
+ dfll_conf.loop_mode = CONF_CLOCK_DFLL_LOOP_MODE;
+ dfll_conf.on_demand = false;
+
+ /* Using DFLL48M COARSE CAL value from NVM Software Calibration Area Mapping
+ in DFLL.COARSE helps to output a frequency close to 48 MHz.*/
+#define NVM_DFLL_COARSE_POS 58 /* DFLL48M Coarse calibration value bit position.*/
+#define NVM_DFLL_COARSE_SIZE 6 /* DFLL48M Coarse calibration value bit size.*/
+
+ uint32_t coarse =( *((uint32_t *)(NVMCTRL_OTP4)
+ + (NVM_DFLL_COARSE_POS / 32))
+ >> (NVM_DFLL_COARSE_POS % 32))
+ & ((1 << NVM_DFLL_COARSE_SIZE) - 1);
+ /* In some revision chip, the coarse calibration value is not correct. */
+ if (coarse == 0x3f) {
+ coarse = 0x1f;
+ }
+ dfll_conf.coarse_value = coarse;
+
+ if (CONF_CLOCK_DFLL_LOOP_MODE == SYSTEM_CLOCK_DFLL_LOOP_MODE_OPEN) {
+ dfll_conf.fine_value = CONF_CLOCK_DFLL_FINE_VALUE;
+ }
+
+# if CONF_CLOCK_DFLL_QUICK_LOCK == true
+ dfll_conf.quick_lock = SYSTEM_CLOCK_DFLL_QUICK_LOCK_ENABLE;
+# else
+ dfll_conf.quick_lock = SYSTEM_CLOCK_DFLL_QUICK_LOCK_DISABLE;
+# endif
+
+# if CONF_CLOCK_DFLL_TRACK_AFTER_FINE_LOCK == true
+ dfll_conf.stable_tracking = SYSTEM_CLOCK_DFLL_STABLE_TRACKING_TRACK_AFTER_LOCK;
+# else
+ dfll_conf.stable_tracking = SYSTEM_CLOCK_DFLL_STABLE_TRACKING_FIX_AFTER_LOCK;
+# endif
+
+# if CONF_CLOCK_DFLL_KEEP_LOCK_ON_WAKEUP == true
+ dfll_conf.wakeup_lock = SYSTEM_CLOCK_DFLL_WAKEUP_LOCK_KEEP;
+# else
+ dfll_conf.wakeup_lock = SYSTEM_CLOCK_DFLL_WAKEUP_LOCK_LOSE;
+# endif
+
+# if CONF_CLOCK_DFLL_ENABLE_CHILL_CYCLE == true
+ dfll_conf.chill_cycle = SYSTEM_CLOCK_DFLL_CHILL_CYCLE_ENABLE;
+# else
+ dfll_conf.chill_cycle = SYSTEM_CLOCK_DFLL_CHILL_CYCLE_DISABLE;
+# endif
+
+ if (CONF_CLOCK_DFLL_LOOP_MODE == SYSTEM_CLOCK_DFLL_LOOP_MODE_CLOSED) {
+ dfll_conf.multiply_factor = CONF_CLOCK_DFLL_MULTIPLY_FACTOR;
+ }
+
+ dfll_conf.coarse_max_step = CONF_CLOCK_DFLL_MAX_COARSE_STEP_SIZE;
+ dfll_conf.fine_max_step = CONF_CLOCK_DFLL_MAX_FINE_STEP_SIZE;
+
+ if (CONF_CLOCK_DFLL_LOOP_MODE == SYSTEM_CLOCK_DFLL_LOOP_MODE_USB_RECOVERY) {
+ dfll_conf.fine_value = 0x1ff;
+ dfll_conf.quick_lock = SYSTEM_CLOCK_DFLL_QUICK_LOCK_ENABLE;
+ dfll_conf.stable_tracking = SYSTEM_CLOCK_DFLL_STABLE_TRACKING_FIX_AFTER_LOCK;
+ dfll_conf.wakeup_lock = SYSTEM_CLOCK_DFLL_WAKEUP_LOCK_KEEP;
+ dfll_conf.chill_cycle = SYSTEM_CLOCK_DFLL_CHILL_CYCLE_DISABLE;
+
+ dfll_conf.multiply_factor = 48000;
+ }
+
+ system_clock_source_dfll_set_config(&dfll_conf);
+#endif
+
+
+ /* OSC8M */
+ struct system_clock_source_osc8m_config osc8m_conf;
+ system_clock_source_osc8m_get_config_defaults(&osc8m_conf);
+
+ osc8m_conf.prescaler = CONF_CLOCK_OSC8M_PRESCALER;
+ osc8m_conf.on_demand = CONF_CLOCK_OSC8M_ON_DEMAND;
+ osc8m_conf.run_in_standby = CONF_CLOCK_OSC8M_RUN_IN_STANDBY;
+
+ system_clock_source_osc8m_set_config(&osc8m_conf);
+ system_clock_source_enable(SYSTEM_CLOCK_SOURCE_OSC8M);
+
+
+ /* GCLK */
+#if CONF_CLOCK_CONFIGURE_GCLK == true
+ system_gclk_init();
+
+ /* Configure all GCLK generators except for the main generator, which
+ * is configured later after all other clock systems are set up */
+ MREPEAT(GCLK_GEN_NUM, _CONF_CLOCK_GCLK_CONFIG_NONMAIN, ~);
+
+# if CONF_CLOCK_DFLL_ENABLE == true
+ /* Enable DFLL reference clock if in closed loop mode */
+ if (CONF_CLOCK_DFLL_LOOP_MODE == SYSTEM_CLOCK_DFLL_LOOP_MODE_CLOSED) {
+ struct system_gclk_chan_config dfll_gclk_chan_conf;
+
+ system_gclk_chan_get_config_defaults(&dfll_gclk_chan_conf);
+ dfll_gclk_chan_conf.source_generator = CONF_CLOCK_DFLL_SOURCE_GCLK_GENERATOR;
+ system_gclk_chan_set_config(SYSCTRL_GCLK_ID_DFLL48, &dfll_gclk_chan_conf);
+ system_gclk_chan_enable(SYSCTRL_GCLK_ID_DFLL48);
+ }
+# endif
+
+# if CONF_CLOCK_DPLL_ENABLE == true
+ /* Enable DPLL internal lock timer and reference clock */
+ struct system_gclk_chan_config dpll_gclk_chan_conf;
+ system_gclk_chan_get_config_defaults(&dpll_gclk_chan_conf);
+ if (CONF_CLOCK_DPLL_LOCK_TIME != SYSTEM_CLOCK_SOURCE_DPLL_LOCK_TIME_DEFAULT) {
+ dpll_gclk_chan_conf.source_generator = CONF_CLOCK_DPLL_LOCK_GCLK_GENERATOR;
+ system_gclk_chan_set_config(SYSCTRL_GCLK_ID_FDPLL32K, &dpll_gclk_chan_conf);
+ system_gclk_chan_enable(SYSCTRL_GCLK_ID_FDPLL32K);
+ }
+
+ if (CONF_CLOCK_DPLL_REFERENCE_CLOCK == SYSTEM_CLOCK_SOURCE_DPLL_REFERENCE_CLOCK_GCLK) {
+ dpll_gclk_chan_conf.source_generator = CONF_CLOCK_DPLL_REFERENCE_GCLK_GENERATOR;
+ system_gclk_chan_set_config(SYSCTRL_GCLK_ID_FDPLL, &dpll_gclk_chan_conf);
+ system_gclk_chan_enable(SYSCTRL_GCLK_ID_FDPLL);
+ }
+# endif
+#endif
+
+
+ /* DFLL Enable (Open and Closed Loop) */
+#if CONF_CLOCK_DFLL_ENABLE == true
+ system_clock_source_enable(SYSTEM_CLOCK_SOURCE_DFLL);
+ while(!system_clock_source_is_ready(SYSTEM_CLOCK_SOURCE_DFLL));
+ if (CONF_CLOCK_DFLL_ON_DEMAND) {
+ SYSCTRL->DFLLCTRL.bit.ONDEMAND = 1;
+ }
+#endif
+
+ /* DPLL */
+#ifdef FEATURE_SYSTEM_CLOCK_DPLL
+# if (CONF_CLOCK_DPLL_ENABLE == true)
+
+ /* Enable DPLL reference clock */
+ if (CONF_CLOCK_DPLL_REFERENCE_CLOCK == SYSTEM_CLOCK_SOURCE_DPLL_REFERENCE_CLOCK_XOSC32K) {
+ /* XOSC32K should have been enabled for DPLL_REF0 */
+ Assert(CONF_CLOCK_XOSC32K_ENABLE);
+ } else if (CONF_CLOCK_DPLL_REFERENCE_CLOCK == SYSTEM_CLOCK_SOURCE_DPLL_REFERENCE_CLOCK_XOSC) {
+ /* XOSC should have been enabled for DPLL_REF1 */
+ Assert(CONF_CLOCK_XOSC_ENABLE);
+ } else if (CONF_CLOCK_DPLL_REFERENCE_CLOCK == SYSTEM_CLOCK_SOURCE_DPLL_REFERENCE_CLOCK_GCLK) {
+ /* GCLK should have been enabled */
+ Assert(CONF_CLOCK_CONFIGURE_GCLK);
+ } else {
+ Assert(false);
+ }
+
+ struct system_clock_source_dpll_config dpll_config;
+ system_clock_source_dpll_get_config_defaults(&dpll_config);
+
+ dpll_config.on_demand = false;
+ dpll_config.run_in_standby = CONF_CLOCK_DPLL_RUN_IN_STANDBY;
+ dpll_config.lock_bypass = CONF_CLOCK_DPLL_LOCK_BYPASS;
+ dpll_config.wake_up_fast = CONF_CLOCK_DPLL_WAKE_UP_FAST;
+ dpll_config.low_power_enable = CONF_CLOCK_DPLL_LOW_POWER_ENABLE;
+
+ dpll_config.filter = CONF_CLOCK_DPLL_FILTER;
+ dpll_config.lock_time = CONF_CLOCK_DPLL_LOCK_TIME;
+
+ dpll_config.reference_clock = CONF_CLOCK_DPLL_REFERENCE_CLOCK;
+ dpll_config.reference_frequency = CONF_CLOCK_DPLL_REFERENCE_FREQUENCY;
+ dpll_config.reference_divider = CONF_CLOCK_DPLL_REFERENCE_DIVIDER;
+ dpll_config.output_frequency = CONF_CLOCK_DPLL_OUTPUT_FREQUENCY;
+
+ system_clock_source_dpll_set_config(&dpll_config);
+ system_clock_source_enable(SYSTEM_CLOCK_SOURCE_DPLL);
+ while(!system_clock_source_is_ready(SYSTEM_CLOCK_SOURCE_DPLL));
+ if (CONF_CLOCK_DPLL_ON_DEMAND) {
+ SYSCTRL->DPLLCTRLA.bit.ONDEMAND = 1;
+ }
+
+# endif
+#endif
+
+ /* CPU and BUS clocks */
+ system_cpu_clock_set_divider(CONF_CLOCK_CPU_DIVIDER);
+
+ system_apb_clock_set_divider(SYSTEM_CLOCK_APB_APBA, CONF_CLOCK_APBA_DIVIDER);
+ system_apb_clock_set_divider(SYSTEM_CLOCK_APB_APBB, CONF_CLOCK_APBB_DIVIDER);
+ system_apb_clock_set_divider(SYSTEM_CLOCK_APB_APBC, CONF_CLOCK_APBC_DIVIDER);
+
+ /* GCLK 0 */
+#if CONF_CLOCK_CONFIGURE_GCLK == true
+ /* Configure the main GCLK last as it might depend on other generators */
+ _CONF_CLOCK_GCLK_CONFIG(0, ~);
+#endif
+}