57 lines
1.9 KiB
C
57 lines
1.9 KiB
C
/* Copyright 2018 Canaan Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stddef.h>
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#include "io.h"
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#include "plic.h"
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#include "pwm.h"
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#include "sysctl.h"
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#include "timer.h"
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#include "utils.h"
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void pwm_init(pwm_device_number_t pwm_number)
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{
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sysctl_clock_enable(SYSCTL_CLOCK_TIMER0 + pwm_number);
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}
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void pwm_set_enable(pwm_device_number_t pwm_number, pwm_channel_number_t channel, int enable)
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{
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if(enable)
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{
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if(timer[pwm_number]->channel[channel].load_count == 0)
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timer[pwm_number]->channel[channel].load_count = 1;
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if(timer[pwm_number]->load_count2[channel] == 0)
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timer[pwm_number]->load_count2[channel] = 1;
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timer[pwm_number]->channel[channel].control = TIMER_CR_INTERRUPT_MASK | TIMER_CR_PWM_ENABLE | TIMER_CR_USER_MODE | TIMER_CR_ENABLE;
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} else
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{
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timer[pwm_number]->channel[channel].control = TIMER_CR_INTERRUPT_MASK;
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}
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}
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double pwm_set_frequency(pwm_device_number_t pwm_number, pwm_channel_number_t channel, double frequency, double duty)
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{
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uint32_t clk_freq = sysctl_clock_get_freq(SYSCTL_CLOCK_TIMER0 + pwm_number);
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int32_t periods = (int32_t)(clk_freq / frequency);
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configASSERT(periods > 0 && periods <= INT32_MAX);
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frequency = clk_freq / (double)periods;
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uint32_t percent = (uint32_t)(duty * periods);
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timer[pwm_number]->channel[channel].load_count = periods - percent;
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timer[pwm_number]->load_count2[channel] = percent;
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return frequency;
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}
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