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/*
* Copyright (c) 2015 Nordic Semiconductor ASA
* All rights reserved.
*
* 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, except as embedded into a Nordic Semiconductor ASA
* integrated circuit in a product or a software update for such product, 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. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific prior
* written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary or object form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* 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 HOLDER 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 "app_pwm.h"
#include "nrf_drv_timer.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_common.h"
#include "nrf_drv_gpiote.h"
#include "nrf_gpiote.h"
#include "nrf_gpio.h"
#include "app_util.h"
#include "app_util_platform.h"
#include "nrf_assert.h"
#define APP_PWM_CHANNEL_INITIALIZED 1
#define APP_PWM_CHANNEL_UNINITIALIZED 0
#define APP_PWM_CHANNEL_ENABLED 1
#define APP_PWM_CHANNEL_DISABLED 0
#define TIMER_PRESCALER_MAX 9
#define TIMER_MAX_PULSEWIDTH_US_ON_16M 4095
#define APP_PWM_REQUIRED_PPI_CHANNELS_PER_INSTANCE 2
#define APP_PWM_REQUIRED_PPI_CHANNELS_PER_CHANNEL 2
#define UNALLOCATED 0xFFFFFFFFUL
#define BUSY_STATE_CHANGING 0xFE
#define BUSY_STATE_IDLE 0xFF
#define PWM_MAIN_CC_CHANNEL 2
#define PWM_SECONDARY_CC_CHANNEL 3
#ifdef NRF52
static bool m_use_ppi_delay_workaround;
#endif
/**
* @brief PWM busy status
*
* Stores the number of a channel being currently updated.
*
*/
static volatile uint8_t m_pwm_busy[TIMER_COUNT];
/**
* @brief New duty cycle value
*
* When the channel duty cycle reaches this value, the update process is complete.
*/
static volatile uint32_t m_pwm_target_value[TIMER_COUNT];
/**
* @brief PWM ready counter
*
* The value in this counter is decremented in every PWM cycle after initiating the update.
* If an event handler function was specified by the user, it is being called
* after two cycle events (at least one full PWM cycle).
*/
volatile uint8_t m_pwm_ready_counter[TIMER_COUNT][APP_PWM_CHANNELS_PER_INSTANCE];
/**
* @brief Pointers to instances
*
* This array connects any active timer instance number with the pointer to the PWM instance.
* It is used by the interrupt runtime.
*/
static const app_pwm_t * m_instances[TIMER_COUNT];
// Macros for getting the polarity of given instance/channel.
#define POLARITY_ACTIVE(INST,CH) (( ((INST)->p_cb)->channels_cb[(CH)].polarity == \
APP_PWM_POLARITY_ACTIVE_LOW)?(0):(1))
#define POLARITY_INACTIVE(INST,CH) (( ((INST)->p_cb)->channels_cb[(CH)].polarity == \
APP_PWM_POLARITY_ACTIVE_LOW)?(1):(0))
//lint -save -e534
/**
* @brief Workaround for PAN-73.
*
* @param[in] timer Timer.
* @param[in] enable Enable or disable.
*/
static void pan73_workaround(NRF_TIMER_Type * p_timer, bool enable)
{
#ifdef NRF51
if (p_timer == NRF_TIMER0)
{
*(uint32_t *)0x40008C0C = (enable ? 1 : 0);
}
else if (p_timer == NRF_TIMER1)
{
*(uint32_t *)0x40009C0C = (enable ? 1 : 0);
}
else if (p_timer == NRF_TIMER2)
{
*(uint32_t *)0x4000AC0C = (enable ? 1 : 0);
}
#endif
return;
}
bool app_pwm_busy_check(app_pwm_t const * const p_instance)
{
uint8_t busy_state = (m_pwm_busy[p_instance->p_timer->instance_id]);
bool busy = true;
if (busy_state != BUSY_STATE_IDLE)
{
if (busy_state != BUSY_STATE_CHANGING)
{
if (nrf_drv_timer_capture_get(p_instance->p_timer, (nrf_timer_cc_channel_t) busy_state)
== m_pwm_target_value[p_instance->p_timer->instance_id])
{
m_pwm_busy[p_instance->p_timer->instance_id] = BUSY_STATE_IDLE;
busy = false;
}
}
}
else
{
busy = false;
}
return busy;
}
/**
* @brief Function for enabling the IRQ for a given PWM instance.
*
* @param[in] p_instance PWM instance.
*/
__STATIC_INLINE void pwm_irq_enable(app_pwm_t const * const p_instance)
{
nrf_drv_timer_compare_int_enable(p_instance->p_timer, PWM_MAIN_CC_CHANNEL);
}
/**
* @brief Function for disabling the IRQ for a given PWM instance.
*
* @param[in] p_instance PWM instance.
*/
__STATIC_INLINE void pwm_irq_disable(app_pwm_t const * const p_instance)
{
nrf_drv_timer_compare_int_disable(p_instance->p_timer, PWM_MAIN_CC_CHANNEL);
}
/**
* @brief Function for disabling PWM channel PPI.
*
* @param[in] p_instance PWM instance.
*/
__STATIC_INLINE void pwm_channel_ppi_disable(app_pwm_t const * const p_instance, uint8_t channel)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
nrf_drv_ppi_channel_disable(p_cb->channels_cb[channel].ppi_channels[0]);
nrf_drv_ppi_channel_disable(p_cb->channels_cb[channel].ppi_channels[1]);
}
/**
* @brief Function for disabling PWM PPI.
*
* @param[in] p_instance PWM instance.
*/
__STATIC_INLINE void pwm_ppi_disable(app_pwm_t const * const p_instance)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
nrf_drv_ppi_channel_disable(p_cb->ppi_channels[0]);
nrf_drv_ppi_channel_disable(p_cb->ppi_channels[1]);
}
/**
* @brief This function is called on interrupt after duty set.
*
* @param[in] timer Timer used by PWM.
* @param[in] timer_instance_id Timer index.
*/
void pwm_ready_tick(nrf_timer_event_t event_type, void * p_context)
{
uint32_t timer_instance_id = (uint32_t)p_context;
uint8_t disable = 1;
for (uint8_t channel = 0; channel < APP_PWM_CHANNELS_PER_INSTANCE; ++channel)
{
if (m_pwm_ready_counter[timer_instance_id][channel])
{
--m_pwm_ready_counter[timer_instance_id][channel];
if (!m_pwm_ready_counter[timer_instance_id][channel])
{
app_pwm_cb_t * p_cb = m_instances[timer_instance_id]->p_cb;
p_cb->p_ready_callback(timer_instance_id);
}
else
{
disable = 0;
}
}
}
if (disable)
{
pwm_irq_disable(m_instances[timer_instance_id]);
}
}
/**
* @brief Function for resource de-allocation.
*
* @param[in] p_instance PWM instance.
*/
//lint -e{650}
static void pwm_dealloc(app_pwm_t const * const p_instance)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
for (uint8_t i = 0; i < APP_PWM_REQUIRED_PPI_CHANNELS_PER_INSTANCE; ++i)
{
if (p_cb->ppi_channels[i] != (nrf_ppi_channel_t)(uint8_t)(UNALLOCATED))
{
nrf_drv_ppi_channel_free(p_cb->ppi_channels[i]);
}
}
if (p_cb->ppi_group != (nrf_ppi_channel_group_t)UNALLOCATED)
{
nrf_drv_ppi_group_free(p_cb->ppi_group);
}
for (uint8_t ch = 0; ch < APP_PWM_CHANNELS_PER_INSTANCE; ++ch)
{
for (uint8_t i = 0; i < APP_PWM_REQUIRED_PPI_CHANNELS_PER_CHANNEL; ++i)
{
if (p_cb->channels_cb[ch].ppi_channels[i] != (nrf_ppi_channel_t)UNALLOCATED)
{
nrf_drv_ppi_channel_free(p_cb->channels_cb[ch].ppi_channels[i]);
p_cb->channels_cb[ch].ppi_channels[i] = (nrf_ppi_channel_t)UNALLOCATED;
}
}
if (p_cb->channels_cb[ch].gpio_pin != UNALLOCATED)
{
nrf_drv_gpiote_out_uninit(p_cb->channels_cb[ch].gpio_pin);
p_cb->channels_cb[ch].gpio_pin = UNALLOCATED;
}
p_cb->channels_cb[ch].initialized = APP_PWM_CHANNEL_UNINITIALIZED;
}
nrf_drv_timer_uninit(p_instance->p_timer);
return;
}
/**
* @brief PWM state transition from (0%, 100%) to 0% or 100%.
*
* @param[in] p_instance PWM instance.
* @param[in] channel PWM channel number.
* @param[in] ticks Number of clock ticks.
*/
static void pwm_transition_n_to_0or100(app_pwm_t const * const p_instance,
uint8_t channel, uint16_t ticks)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
nrf_ppi_channel_group_t p_ppigrp = p_cb->ppi_group;
pwm_ppi_disable(p_instance);
nrf_drv_ppi_group_clear(p_ppigrp);
nrf_drv_ppi_channels_include_in_group(
nrf_drv_ppi_channel_to_mask(p_ch_cb->ppi_channels[0]) |
nrf_drv_ppi_channel_to_mask(p_ch_cb->ppi_channels[1]),
p_ppigrp);
if (!ticks)
{
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[0],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, channel),
nrf_drv_ppi_task_addr_group_disable_get(p_ppigrp));
nrf_drv_timer_compare(p_instance->p_timer, (nrf_timer_cc_channel_t) PWM_SECONDARY_CC_CHANNEL, 0, false);
m_pwm_target_value[p_instance->p_timer->instance_id] =
nrf_drv_timer_capture_get(p_instance->p_timer, (nrf_timer_cc_channel_t) channel);
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[1],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, channel),
nrf_drv_timer_capture_task_address_get(p_instance->p_timer, PWM_SECONDARY_CC_CHANNEL));
}
else
{
ticks = p_cb->period;
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[0],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_MAIN_CC_CHANNEL),
nrf_drv_ppi_task_addr_group_disable_get(p_ppigrp));
// Set secondary CC channel to non-zero value:
nrf_drv_timer_compare(p_instance->p_timer, (nrf_timer_cc_channel_t) PWM_SECONDARY_CC_CHANNEL, 1, false);
m_pwm_target_value[p_instance->p_timer->instance_id] = 0;
// The captured value will be equal to 0, because timer clear on main PWM CC channel compare is enabled.
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[1],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_MAIN_CC_CHANNEL),
nrf_drv_timer_capture_task_address_get(p_instance->p_timer, PWM_SECONDARY_CC_CHANNEL));
}
nrf_drv_ppi_channel_enable(p_cb->ppi_channels[0]);
nrf_drv_ppi_channel_enable(p_cb->ppi_channels[1]);
p_ch_cb->pulsewidth = ticks;
m_pwm_busy[p_instance->p_timer->instance_id] = PWM_SECONDARY_CC_CHANNEL;
}
/**
* @brief PWM state transition from (0%, 100%) to (0%, 100%).
*
* @param[in] p_instance PWM instance.
* @param[in] channel PWM channel number.
* @param[in] ticks Number of clock ticks.
*/
static void pwm_transition_n_to_m(app_pwm_t const * const p_instance,
uint8_t channel, uint16_t ticks)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
nrf_ppi_channel_group_t p_ppigrp = p_cb->ppi_group;
pwm_ppi_disable(p_instance);
nrf_drv_ppi_group_clear(p_ppigrp);
nrf_drv_ppi_channels_include_in_group(
nrf_drv_ppi_channel_to_mask(p_cb->ppi_channels[0]) |
nrf_drv_ppi_channel_to_mask(p_cb->ppi_channels[1]),
p_ppigrp);
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[0],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_SECONDARY_CC_CHANNEL),
nrf_drv_timer_capture_task_address_get(p_instance->p_timer, channel));
#ifdef NRF52
if (ticks + ((nrf_timer_frequency_get(p_instance->p_timer->p_reg) ==
(m_use_ppi_delay_workaround ? NRF_TIMER_FREQ_8MHz : NRF_TIMER_FREQ_16MHz) ) ? 1U : 0U)
< p_ch_cb->pulsewidth)
#else
if (ticks + ((nrf_timer_frequency_get(p_instance->p_timer->p_reg) == NRF_TIMER_FREQ_16MHz) ? 1U : 0U)
< p_ch_cb->pulsewidth)
#endif
{
// For lower value, we need one more transition. Timer task delay is included.
// If prescaler is disabled, one tick must be added because of 1 PCLK16M clock cycle delay.
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[1],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_SECONDARY_CC_CHANNEL),
nrf_drv_gpiote_out_task_addr_get(p_ch_cb->gpio_pin));
}
else
{
nrf_drv_ppi_channel_remove_from_group(p_cb->ppi_channels[1], p_ppigrp);
}
p_ch_cb->pulsewidth = ticks;
nrf_drv_timer_compare(p_instance->p_timer, (nrf_timer_cc_channel_t) PWM_SECONDARY_CC_CHANNEL, ticks, false);
nrf_drv_ppi_group_enable(p_ppigrp);
m_pwm_target_value[p_instance->p_timer->instance_id] = ticks;
m_pwm_busy[p_instance->p_timer->instance_id] = channel;
}
/**
* @brief PWM state transition from 0% or 100% to (0%, 100%).
*
* @param[in] p_instance PWM instance.
* @param[in] channel PWM channel number.
* @param[in] ticks Number of clock ticks.
*/
static void pwm_transition_0or100_to_n(app_pwm_t const * const p_instance,
uint8_t channel, uint16_t ticks)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
nrf_ppi_channel_group_t p_ppigrp = p_cb->ppi_group;
nrf_timer_cc_channel_t pwm_ch_cc = (nrf_timer_cc_channel_t)(channel);
pwm_ppi_disable(p_instance);
pwm_channel_ppi_disable(p_instance, channel);
nrf_drv_timer_compare(p_instance->p_timer, pwm_ch_cc, ticks, false);
nrf_drv_ppi_group_clear(p_ppigrp);
nrf_drv_ppi_channels_include_in_group(
nrf_drv_ppi_channel_to_mask(p_ch_cb->ppi_channels[0])|
nrf_drv_ppi_channel_to_mask(p_ch_cb->ppi_channels[1]),
p_ppigrp);
if (!p_ch_cb->pulsewidth)
{
// Channel is at 0%.
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[0],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, channel),
nrf_drv_ppi_task_addr_group_enable_get(p_ppigrp));
nrf_drv_timer_compare(p_instance->p_timer, (nrf_timer_cc_channel_t) PWM_SECONDARY_CC_CHANNEL, 0, false);
m_pwm_target_value[p_instance->p_timer->instance_id] =
nrf_drv_timer_capture_get(p_instance->p_timer, (nrf_timer_cc_channel_t) channel);
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[1],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, channel),
nrf_drv_timer_capture_task_address_get(p_instance->p_timer, PWM_SECONDARY_CC_CHANNEL));
}
else
{
// Channel is at 100%.
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[0],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_MAIN_CC_CHANNEL),
nrf_drv_ppi_task_addr_group_enable_get(p_ppigrp));
// Set secondary CC channel to non-zero value:
nrf_drv_timer_compare(p_instance->p_timer, (nrf_timer_cc_channel_t) PWM_SECONDARY_CC_CHANNEL, 1, false);
m_pwm_target_value[p_instance->p_timer->instance_id] = 0;
// The captured value will be equal to 0, because timer clear on main PWM CC channel compare is enabled.
nrf_drv_ppi_channel_assign(p_cb->ppi_channels[1],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_MAIN_CC_CHANNEL),
nrf_drv_timer_capture_task_address_get(p_instance->p_timer, PWM_SECONDARY_CC_CHANNEL));
}
nrf_drv_ppi_channel_enable(p_cb->ppi_channels[0]);
nrf_drv_ppi_channel_enable(p_cb->ppi_channels[1]);
p_ch_cb->pulsewidth = ticks;
m_pwm_busy[p_instance->p_timer->instance_id] = PWM_SECONDARY_CC_CHANNEL;
}
/**
* @brief PWM state transition from 0% or 100% to 0% or 100%.
*
* @param[in] p_instance PWM instance.
* @param[in] channel PWM channel number.
* @param[in] ticks Number of clock ticks.
*/
static void pwm_transition_0or100_to_0or100(app_pwm_t const * const p_instance,
uint8_t channel, uint16_t ticks)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
nrf_timer_cc_channel_t pwm_ch_cc = (nrf_timer_cc_channel_t)(channel);
pwm_ppi_disable(p_instance);
pwm_channel_ppi_disable(p_instance, channel);
if (!ticks)
{
// Set to 0%.
nrf_drv_gpiote_out_task_force(p_ch_cb->gpio_pin, POLARITY_INACTIVE(p_instance, channel));
}
else if (ticks >= p_cb->period)
{
// Set to 100%.
ticks = p_cb->period;
nrf_drv_gpiote_out_task_force(p_ch_cb->gpio_pin, POLARITY_ACTIVE(p_instance, channel));
}
nrf_drv_timer_compare(p_instance->p_timer, pwm_ch_cc, ticks, false);
p_ch_cb->pulsewidth = ticks;
m_pwm_busy[p_instance->p_timer->instance_id] = BUSY_STATE_IDLE;
return;
}
ret_code_t app_pwm_channel_duty_ticks_set(app_pwm_t const * const p_instance,
uint8_t channel,
uint16_t ticks)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
ASSERT(channel < APP_PWM_CHANNELS_PER_INSTANCE);
ASSERT(p_ch_cb->initialized == APP_PWM_CHANNEL_INITIALIZED);
if (p_cb->state != NRF_DRV_STATE_POWERED_ON)
{
return NRF_ERROR_INVALID_STATE;
}
if (ticks == p_ch_cb->pulsewidth)
{
if (p_cb->p_ready_callback)
{
p_cb->p_ready_callback(p_instance->p_timer->instance_id);
}
return NRF_SUCCESS; // No action required.
}
if (app_pwm_busy_check(p_instance))
{
return NRF_ERROR_BUSY; // PPI channels for synchronization are still in use.
}
m_pwm_busy[p_instance->p_timer->instance_id] = BUSY_STATE_CHANGING;
// Pulse width change sequence:
if (!p_ch_cb->pulsewidth || p_ch_cb->pulsewidth >= p_cb->period)
{
// Channel is disabled (0%) or at 100%.
if (!ticks || ticks >= p_cb->period)
{
// Set to 0 or 100%.
pwm_transition_0or100_to_0or100(p_instance, channel, ticks);
}
else
{
// Other value.
pwm_transition_0or100_to_n(p_instance, channel, ticks);
}
}
else
{
// Channel is at other value.
if (!ticks || ticks >= p_cb->period)
{
// Disable channel (set to 0%) or set to 100%.
pwm_transition_n_to_0or100(p_instance, channel, ticks);
}
else
{
// Set to any other value.
pwm_transition_n_to_m(p_instance, channel, ticks);
}
}
if (p_instance->p_cb->p_ready_callback)
{
//PWM ready interrupt handler will be called after one full period.
m_pwm_ready_counter[p_instance->p_timer->instance_id][channel] = 2;
pwm_irq_enable(p_instance);
}
return NRF_SUCCESS;
}
uint16_t app_pwm_channel_duty_ticks_get(app_pwm_t const * const p_instance, uint8_t channel)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
return p_ch_cb->pulsewidth;
}
uint16_t app_pwm_cycle_ticks_get(app_pwm_t const * const p_instance)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
return (uint16_t)p_cb->period;
}
ret_code_t app_pwm_channel_duty_set(app_pwm_t const * const p_instance,
uint8_t channel, app_pwm_duty_t duty)
{
uint32_t ticks = ((uint32_t)app_pwm_cycle_ticks_get(p_instance) * (uint32_t)duty) / 100UL;
return app_pwm_channel_duty_ticks_set(p_instance, channel, ticks);
}
app_pwm_duty_t app_pwm_channel_duty_get(app_pwm_t const * const p_instance, uint8_t channel)
{
uint32_t value = ((uint32_t)app_pwm_channel_duty_ticks_get(p_instance, channel) * 100UL) \
/ (uint32_t)app_pwm_cycle_ticks_get(p_instance);
return (app_pwm_duty_t)value;
}
/**
* @brief Function for initializing the PWM channel.
*
* @param[in] p_instance PWM instance.
* @param[in] channel Channel number.
* @param[in] pin GPIO pin number.
*
* @retval NRF_SUCCESS If initialization was successful.
* @retval NRF_ERROR_NO_MEM If there were not enough free resources.
* @retval NRF_ERROR_INVALID_STATE If the timer is already in use or initialization failed.
*/
static ret_code_t app_pwm_channel_init(app_pwm_t const * const p_instance, uint8_t channel,
uint32_t pin, app_pwm_polarity_t polarity)
{
ASSERT(channel < APP_PWM_CHANNELS_PER_INSTANCE);
app_pwm_cb_t * p_cb = p_instance->p_cb;
app_pwm_channel_cb_t * p_channel_cb = &p_cb->channels_cb[channel];
if (p_cb->state != NRF_DRV_STATE_UNINITIALIZED)
{
return NRF_ERROR_INVALID_STATE;
}
p_channel_cb->pulsewidth = 0;
p_channel_cb->polarity = polarity;
ret_code_t err_code;
/* GPIOTE setup: */
nrf_drv_gpiote_out_config_t out_cfg = GPIOTE_CONFIG_OUT_TASK_TOGGLE( POLARITY_INACTIVE(p_instance, channel) );
err_code = nrf_drv_gpiote_out_init((nrf_drv_gpiote_pin_t)pin,&out_cfg);
if (err_code != NRF_SUCCESS)
{
return NRF_ERROR_NO_MEM;
}
p_cb->channels_cb[channel].gpio_pin = pin;
// Set output to inactive state.
if (polarity)
{
nrf_gpio_pin_clear(pin);
}
else
{
nrf_gpio_pin_set(pin);
}
/* PPI setup: */
for (uint8_t i = 0; i < APP_PWM_REQUIRED_PPI_CHANNELS_PER_CHANNEL; ++i)
{
if (nrf_drv_ppi_channel_alloc(&p_channel_cb->ppi_channels[i]) != NRF_SUCCESS)
{
return NRF_ERROR_NO_MEM; // Resource de-allocation is done by callee.
}
}
nrf_drv_ppi_channel_disable(p_channel_cb->ppi_channels[0]);
nrf_drv_ppi_channel_disable(p_channel_cb->ppi_channels[1]);
nrf_drv_ppi_channel_assign(p_channel_cb->ppi_channels[0],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, channel),
nrf_drv_gpiote_out_task_addr_get(p_channel_cb->gpio_pin));
nrf_drv_ppi_channel_assign(p_channel_cb->ppi_channels[1],
nrf_drv_timer_compare_event_address_get(p_instance->p_timer, PWM_MAIN_CC_CHANNEL),
nrf_drv_gpiote_out_task_addr_get(p_channel_cb->gpio_pin));
p_channel_cb->initialized = APP_PWM_CHANNEL_INITIALIZED;
m_pwm_ready_counter[p_instance->p_timer->instance_id][channel] = 0;
return NRF_SUCCESS;
}
/**
* @brief Function for calculating target timer frequency, which will allow to set given period length.
*
* @param[in] period_us Desired period in microseconds.
*
* @retval Timer frequency.
*/
__STATIC_INLINE nrf_timer_frequency_t pwm_calculate_timer_frequency(uint32_t period_us)
{
uint32_t f = (uint32_t) NRF_TIMER_FREQ_16MHz;
uint32_t min = (uint32_t) NRF_TIMER_FREQ_31250Hz;
while ((period_us > TIMER_MAX_PULSEWIDTH_US_ON_16M) && (f < min))
{
period_us >>= 1;
++f;
}
#ifdef NRF52
if ((m_use_ppi_delay_workaround) && (f == (uint32_t) NRF_TIMER_FREQ_16MHz))
{
f = (uint32_t) NRF_TIMER_FREQ_8MHz;
}
#endif
return (nrf_timer_frequency_t) f;
}
ret_code_t app_pwm_init(app_pwm_t const * const p_instance, app_pwm_config_t const * const p_config,
app_pwm_callback_t p_ready_callback)
{
ASSERT(p_instance);
if (!p_config)
{
return NRF_ERROR_INVALID_DATA;
}
app_pwm_cb_t * p_cb = p_instance->p_cb;
if (p_cb->state != NRF_DRV_STATE_UNINITIALIZED)
{
return NRF_ERROR_INVALID_STATE;
}
uint32_t err_code = nrf_drv_ppi_init();
if ((err_code != NRF_SUCCESS) && (err_code != MODULE_ALREADY_INITIALIZED))
{
return NRF_ERROR_NO_MEM;
}
if (!nrf_drv_gpiote_is_init())
{
err_code = nrf_drv_gpiote_init();
if (err_code != NRF_SUCCESS)
{
return NRF_ERROR_INTERNAL;
}
}
#ifdef NRF52
if (((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x30)
{
m_use_ppi_delay_workaround = false;
}
else
{
m_use_ppi_delay_workaround = true;
}
#endif
// Innitialize resource status:
p_cb->ppi_channels[0] = (nrf_ppi_channel_t)UNALLOCATED;
p_cb->ppi_channels[1] = (nrf_ppi_channel_t)UNALLOCATED;
p_cb->ppi_group = (nrf_ppi_channel_group_t)UNALLOCATED;
for (uint8_t i = 0; i < APP_PWM_CHANNELS_PER_INSTANCE; ++i)
{
p_cb->channels_cb[i].initialized = APP_PWM_CHANNEL_UNINITIALIZED;
p_cb->channels_cb[i].ppi_channels[0] = (nrf_ppi_channel_t)UNALLOCATED;
p_cb->channels_cb[i].ppi_channels[1] = (nrf_ppi_channel_t)UNALLOCATED;
p_cb->channels_cb[i].gpio_pin = UNALLOCATED;
}
// Allocate PPI channels and groups:
for (uint8_t i = 0; i < APP_PWM_REQUIRED_PPI_CHANNELS_PER_INSTANCE; ++i)
{
if (nrf_drv_ppi_channel_alloc(&p_cb->ppi_channels[i]) != NRF_SUCCESS)
{
pwm_dealloc(p_instance);
return NRF_ERROR_NO_MEM;
}
}
if (nrf_drv_ppi_group_alloc(&p_cb->ppi_group) != NRF_SUCCESS)
{
pwm_dealloc(p_instance);
return NRF_ERROR_NO_MEM;
}
// Initialize channels:
for (uint8_t i = 0; i < APP_PWM_CHANNELS_PER_INSTANCE; ++i)
{
if (p_config->pins[i] != APP_PWM_NOPIN)
{
err_code = app_pwm_channel_init(p_instance, i, p_config->pins[i], p_config->pin_polarity[i]);
if (err_code != NRF_SUCCESS)
{
pwm_dealloc(p_instance);
return err_code;
}
app_pwm_channel_duty_ticks_set(p_instance, i, 0);
}
}
// Initialize timer:
nrf_timer_frequency_t timer_freq = pwm_calculate_timer_frequency(p_config->period_us);
nrf_drv_timer_config_t timer_cfg = {
.frequency = timer_freq,
.mode = NRF_TIMER_MODE_TIMER,
.bit_width = NRF_TIMER_BIT_WIDTH_16,
.interrupt_priority = APP_IRQ_PRIORITY_LOW,
.p_context = (void *) (uint32_t) p_instance->p_timer->instance_id
};
err_code = nrf_drv_timer_init(p_instance->p_timer, &timer_cfg,
pwm_ready_tick);
if (err_code != NRF_SUCCESS)
{
pwm_dealloc(p_instance);
return err_code;
}
uint32_t ticks = nrf_drv_timer_us_to_ticks(p_instance->p_timer, p_config->period_us);
p_cb->period = ticks;
nrf_drv_timer_clear(p_instance->p_timer);
nrf_drv_timer_extended_compare(p_instance->p_timer, (nrf_timer_cc_channel_t) PWM_MAIN_CC_CHANNEL,
ticks, NRF_TIMER_SHORT_COMPARE2_CLEAR_MASK, true);
nrf_drv_timer_compare_int_disable(p_instance->p_timer, PWM_MAIN_CC_CHANNEL);
p_cb->p_ready_callback = p_ready_callback;
m_instances[p_instance->p_timer->instance_id] = p_instance;
m_pwm_busy[p_instance->p_timer->instance_id] = BUSY_STATE_IDLE;
p_cb->state = NRF_DRV_STATE_INITIALIZED;
return NRF_SUCCESS;
}
void app_pwm_enable(app_pwm_t const * const p_instance)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
ASSERT(p_cb->state != NRF_DRV_STATE_UNINITIALIZED);
for (uint32_t channel = 0; channel < APP_PWM_CHANNELS_PER_INSTANCE; ++channel)
{
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
m_pwm_ready_counter[p_instance->p_timer->instance_id][channel] = 0;
if (p_ch_cb->initialized)
{
nrf_drv_gpiote_out_task_force(p_ch_cb->gpio_pin, POLARITY_INACTIVE(p_instance, channel));
nrf_drv_gpiote_out_task_enable(p_ch_cb->gpio_pin);
p_ch_cb->pulsewidth = 0;
}
}
m_pwm_busy[p_instance->p_timer->instance_id] = BUSY_STATE_IDLE;
pan73_workaround(p_instance->p_timer->p_reg, true);
nrf_drv_timer_clear(p_instance->p_timer);
nrf_drv_timer_enable(p_instance->p_timer);
p_cb->state = NRF_DRV_STATE_POWERED_ON;
return;
}
void app_pwm_disable(app_pwm_t const * const p_instance)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
ASSERT(p_cb->state != NRF_DRV_STATE_UNINITIALIZED);
nrf_drv_timer_disable(p_instance->p_timer);
pwm_irq_disable(p_instance);
for (uint8_t ppi_channel = 0; ppi_channel < APP_PWM_REQUIRED_PPI_CHANNELS_PER_INSTANCE; ++ppi_channel)
{
nrf_drv_ppi_channel_disable(p_cb->ppi_channels[ppi_channel]);
}
for (uint8_t channel = 0; channel < APP_PWM_CHANNELS_PER_INSTANCE; ++channel)
{
app_pwm_channel_cb_t * p_ch_cb = &p_cb->channels_cb[channel];
if (p_ch_cb->initialized)
{
uint8_t polarity = POLARITY_INACTIVE(p_instance, channel);
if (polarity)
{
nrf_gpio_pin_set(p_ch_cb->gpio_pin);
}
else
{
nrf_gpio_pin_clear(p_ch_cb->gpio_pin);
}
nrf_drv_gpiote_out_task_disable(p_ch_cb->gpio_pin);
nrf_drv_ppi_channel_disable(p_ch_cb->ppi_channels[0]);
nrf_drv_ppi_channel_disable(p_ch_cb->ppi_channels[1]);
}
}
pan73_workaround(p_instance->p_timer->p_reg, false);
p_cb->state = NRF_DRV_STATE_INITIALIZED;
return;
}
ret_code_t app_pwm_uninit(app_pwm_t const * const p_instance)
{
app_pwm_cb_t * p_cb = p_instance->p_cb;
if (p_cb->state == NRF_DRV_STATE_POWERED_ON)
{
app_pwm_disable(p_instance);
}
else if (p_cb->state == NRF_DRV_STATE_UNINITIALIZED)
{
return NRF_ERROR_INVALID_STATE;
}
pwm_dealloc(p_instance);
p_cb->state = NRF_DRV_STATE_UNINITIALIZED;
return NRF_SUCCESS;
}
//lint -restore