120 lines
3.0 KiB
C
120 lines
3.0 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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#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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u32_t id;
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u8_t prescaler;
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u8_t divider;
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};
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#define DEV_CFG(dev) \
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((const struct sam_pwm_config * const)(dev)->config->config_info)
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static int sam_pwm_get_cycles_per_sec(struct device *dev, u32_t pwm,
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u64_t *cycles)
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{
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u8_t prescaler = DEV_CFG(dev)->prescaler;
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u8_t divider = DEV_CFG(dev)->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(struct device *dev, u32_t ch,
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u32_t period_cycles, u32_t pulse_cycles)
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{
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Pwm *const pwm = DEV_CFG(dev)->regs;
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if (ch >= PWMCHNUM_NUMBER) {
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return -EINVAL;
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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(struct device *dev)
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{
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Pwm *const pwm = DEV_CFG(dev)->regs;
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u32_t id = DEV_CFG(dev)->id;
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u8_t prescaler = DEV_CFG(dev)->prescaler;
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u8_t divider = DEV_CFG(dev)->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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#ifdef DT_INST_0_ATMEL_SAM_PWM
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static const struct sam_pwm_config sam_pwm_config_0 = {
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.regs = (Pwm *)DT_INST_0_ATMEL_SAM_PWM_BASE_ADDRESS,
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.id = DT_INST_0_ATMEL_SAM_PWM_PERIPHERAL_ID,
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.prescaler = DT_INST_0_ATMEL_SAM_PWM_PRESCALER,
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.divider = DT_INST_0_ATMEL_SAM_PWM_DIVIDER,
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};
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DEVICE_AND_API_INIT(sam_pwm_0, DT_INST_0_ATMEL_SAM_PWM_LABEL, &sam_pwm_init,
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NULL, &sam_pwm_config_0,
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&sam_pwm_driver_api);
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#endif /* DT_INST_0_ATMEL_SAM_PWM */
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#ifdef DT_INST_1_ATMEL_SAM_PWM
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static const struct sam_pwm_config sam_pwm_config_1 = {
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.regs = (Pwm *)DT_INST_1_ATMEL_SAM_PWM_BASE_ADDRESS,
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.id = DT_INST_1_ATMEL_SAM_PWM_PERIPHERAL_ID,
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.prescaler = DT_INST_1_ATMEL_SAM_PWM_PRESCALER,
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.divider = DT_INST_1_ATMEL_SAM_PWM_DIVIDER,
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};
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DEVICE_AND_API_INIT(sam_pwm_1, DT_INST_1_ATMEL_SAM_PWM_LABEL, &sam_pwm_init,
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NULL, &sam_pwm_config_1,
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&sam_pwm_driver_api);
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#endif /* DT_INST_1_ATMEL_SAM_PWM */
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