/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (C) 2019 embedded brains GmbH
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 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.
*/
#include <bsp/power.h>
#include <bsp/linker-symbols.h>
#include <libchip/chip.h>
BSP_FAST_TEXT_SECTION static void
pmc_wait_for_master_clock_ready(volatile Pmc *pmc)
{
while ((pmc->PMC_SR & PMC_SR_MCKRDY) == 0) {
/* Wait */
}
}
BSP_FAST_TEXT_SECTION static void
pmc_set_master_clock_source(volatile Pmc *pmc, uint32_t mckr)
{
pmc->PMC_MCKR =
(pmc->PMC_MCKR & ~PMC_MCKR_CSS_Msk) | (mckr & PMC_MCKR_CSS_Msk);
}
BSP_FAST_TEXT_SECTION static void
pmc_set_master_clock_prescaler(volatile Pmc *pmc, uint32_t mckr)
{
pmc->PMC_MCKR =
(pmc->PMC_MCKR & ~PMC_MCKR_PRES_Msk) | (mckr & PMC_MCKR_PRES_Msk);
}
BSP_FAST_TEXT_SECTION static void
pmc_set_master_clock_division(volatile Pmc *pmc, uint32_t mckr)
{
pmc->PMC_MCKR =
(pmc->PMC_MCKR & ~PMC_MCKR_MDIV_Msk) | (mckr & PMC_MCKR_MDIV_Msk);
}
BSP_FAST_TEXT_SECTION static void
pmc_wait_for_main_rc_osc(volatile Pmc *pmc)
{
while ((pmc->PMC_SR & PMC_SR_MOSCRCS) == 0) {
/* Wait */
}
}
BSP_FAST_TEXT_SECTION static void
pmc_wait_for_main_osc_selection(volatile Pmc *pmc)
{
while ((pmc->PMC_SR & PMC_SR_MOSCSELS) == 0) {
/* Wait */
}
}
BSP_FAST_TEXT_SECTION static void
pmc_use_main_rc_osc_4mhz(volatile Pmc *pmc)
{
uint32_t ckgr_mor;
ckgr_mor = pmc->CKGR_MOR;
ckgr_mor |= CKGR_MOR_KEY_PASSWD;
/* Enable main RC oscillator */
ckgr_mor |= CKGR_MOR_MOSCRCEN;
PMC->CKGR_MOR = ckgr_mor;
pmc_wait_for_main_rc_osc(pmc);
/* Set main RC oscillator frequency to 4MHz */
ckgr_mor &= ~CKGR_MOR_MOSCRCF_Msk;
ckgr_mor |= CKGR_MOR_MOSCRCF_4_MHz;
pmc->CKGR_MOR = ckgr_mor;
pmc_wait_for_main_rc_osc(pmc);
/* Switch to main RC oscillator */
ckgr_mor &= ~CKGR_MOR_MOSCSEL;
pmc->CKGR_MOR = ckgr_mor;
pmc_wait_for_main_osc_selection(pmc);
pmc_wait_for_master_clock_ready(pmc);
}
BSP_FAST_TEXT_SECTION static void
pmc_use_main_ext_osc(volatile Pmc *pmc)
{
uint32_t ckgr_mor;
ckgr_mor = pmc->CKGR_MOR;
ckgr_mor |= CKGR_MOR_KEY_PASSWD;
/* Enable main external oscillator */
ckgr_mor |= CKGR_MOR_MOSCRCF_12_MHz | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCRCEN |
CKGR_MOR_MOSCXTST(DEFAUTL_MAIN_OSC_COUNT);
PMC->CKGR_MOR = ckgr_mor;
pmc_wait_for_main_rc_osc(pmc);
pmc_wait_for_master_clock_ready(pmc);
/* Switch to main external oscillator */
ckgr_mor |= CKGR_MOR_MOSCSEL;
pmc->CKGR_MOR = ckgr_mor;
pmc_wait_for_main_osc_selection(pmc);
pmc_wait_for_master_clock_ready(pmc);
}
BSP_FAST_TEXT_SECTION void
atsam_power_handler_wait_mode(
const atsam_power_control *control,
atsam_power_state state
)
{
rtems_interrupt_level level;
volatile Pmc *pmc;
uint32_t mckr;
uint32_t fmr;
uint32_t fsmr;
(void) control;
pmc = PMC;
switch (state) {
case ATSAM_POWER_OFF:
rtems_interrupt_disable(level);
mckr = pmc->PMC_MCKR;
/* Switch main clock to main RC oscillator (4MHz) */
pmc_use_main_rc_osc_4mhz(pmc);
pmc_set_master_clock_source(pmc, PMC_MCKR_CSS_MAIN_CLK);
pmc_wait_for_master_clock_ready(pmc);
pmc_set_master_clock_prescaler(pmc, PMC_MCKR_PRES_CLK_1);
pmc_wait_for_master_clock_ready(pmc);
pmc_set_master_clock_division(pmc, PMC_MCKR_MDIV_EQ_PCK);
pmc_wait_for_master_clock_ready(pmc);
/* Set flash wait state to 0 */
fmr = EFC->EEFC_FMR;
EFC->EEFC_FMR = EEFC_FMR_FWS(0);
/* Enter wait mode */
fsmr = pmc->PMC_FSMR;
pmc->PMC_FSMR = fsmr | PMC_FSMR_LPM;
pmc->CKGR_MOR = CKGR_MOR_KEY_PASSWD | CKGR_MOR_WAITMODE;
pmc_wait_for_master_clock_ready(pmc);
__asm__ volatile ( "wfe" : : : "memory" );
pmc->PMC_FSMR = fsmr;
/* Restore main clock */
pmc_set_master_clock_prescaler(pmc, mckr);
pmc_wait_for_master_clock_ready(pmc);
pmc_set_master_clock_division(pmc, mckr);
pmc_wait_for_master_clock_ready(pmc);
pmc_set_master_clock_source(pmc, mckr);
pmc_wait_for_master_clock_ready(pmc);
pmc_use_main_ext_osc(pmc);
/* Restore flash wait state */
EFC->EEFC_FMR = fmr;
rtems_interrupt_enable(level);
break;
case ATSAM_POWER_INIT:
rtems_interrupt_disable(level);
pmc->PMC_FSMR = (pmc->PMC_FSMR & ~PMC_FSMR_FLPM_Msk)
| PMC_FSMR_FLPM(PMC_FSMR_FLPM_FLASH_DEEP_POWERDOWN);
/* No Cortex-M7 Deep Sleep mode (Backup Mode) */
SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;
rtems_interrupt_enable(level);
default:
break;
}
}
