119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/*
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* Copyright (c) 2019 Aurelien Jarno
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT atmel_sam_pwm
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#include <device.h>
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#include <errno.h>
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#include <drivers/pwm.h>
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#include <soc.h>
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#define LOG_LEVEL CONFIG_PWM_LOG_LEVEL
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#include <logging/log.h>
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LOG_MODULE_REGISTER(pwm_sam);
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struct sam_pwm_config {
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Pwm *regs;
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uint32_t id;
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uint8_t prescaler;
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uint8_t divider;
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};
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static int sam_pwm_get_cycles_per_sec(const struct device *dev, uint32_t pwm,
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uint64_t *cycles)
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{
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const struct sam_pwm_config *config = dev->config;
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uint8_t prescaler = config->prescaler;
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uint8_t divider = config->divider;
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*cycles = SOC_ATMEL_SAM_MCK_FREQ_HZ /
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((1 << prescaler) * divider);
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return 0;
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}
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static int sam_pwm_pin_set(const struct device *dev, uint32_t ch,
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uint32_t period_cycles, uint32_t pulse_cycles,
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pwm_flags_t flags)
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{
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const struct sam_pwm_config *config = dev->config;
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Pwm * const pwm = config->regs;
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if (ch >= PWMCHNUM_NUMBER) {
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return -EINVAL;
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}
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if (flags) {
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/* PWM polarity not supported (yet?) */
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return -ENOTSUP;
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}
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if (period_cycles == 0U || pulse_cycles > period_cycles) {
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return -EINVAL;
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}
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if (period_cycles > 0xffff) {
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return -ENOTSUP;
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}
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/* Select clock A */
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pwm->PWM_CH_NUM[ch].PWM_CMR = PWM_CMR_CPRE_CLKA_Val;
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/* Update period and pulse using the update registers, so that the
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* change is triggered at the next PWM period.
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*/
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pwm->PWM_CH_NUM[ch].PWM_CPRDUPD = period_cycles;
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pwm->PWM_CH_NUM[ch].PWM_CDTYUPD = pulse_cycles;
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/* Enable the output */
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pwm->PWM_ENA = 1 << ch;
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return 0;
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}
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static int sam_pwm_init(const struct device *dev)
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{
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const struct sam_pwm_config *config = dev->config;
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Pwm * const pwm = config->regs;
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uint32_t id = config->id;
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uint8_t prescaler = config->prescaler;
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uint8_t divider = config->divider;
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/* FIXME: way to validate prescaler & divider */
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/* Enable the PWM peripheral */
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soc_pmc_peripheral_enable(id);
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/* Configure the clock A that will be used by all 4 channels */
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pwm->PWM_CLK = PWM_CLK_PREA(prescaler) | PWM_CLK_DIVA(divider);
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return 0;
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}
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static const struct pwm_driver_api sam_pwm_driver_api = {
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.pin_set = sam_pwm_pin_set,
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.get_cycles_per_sec = sam_pwm_get_cycles_per_sec,
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};
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#define SAM_INST_INIT(inst) \
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static const struct sam_pwm_config sam_pwm_config_##inst = { \
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.regs = (Pwm *)DT_INST_REG_ADDR(inst), \
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.id = DT_INST_PROP(inst, peripheral_id), \
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.prescaler = DT_INST_PROP(inst, prescaler), \
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.divider = DT_INST_PROP(inst, divider), \
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}; \
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\
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DEVICE_DT_INST_DEFINE(inst, \
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&sam_pwm_init, NULL, \
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NULL, &sam_pwm_config_##inst, \
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POST_KERNEL, \
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
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&sam_pwm_driver_api);
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DT_INST_FOREACH_STATUS_OKAY(SAM_INST_INIT)
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