zephyr/drivers/pwm/pwm_mcux_pwt.c

341 lines
7.9 KiB
C

/*
* Copyright (c) 2021 Vestas Wind Systems A/S
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT nxp_kinetis_pwt
#include <drivers/clock_control.h>
#include <errno.h>
#include <drivers/pwm.h>
#include <soc.h>
#include <fsl_pwt.h>
#include <fsl_clock.h>
#include <logging/log.h>
LOG_MODULE_REGISTER(pwm_mcux_pwt, CONFIG_PWM_LOG_LEVEL);
/* Number of PWT input ports */
#define PWT_INPUTS 4U
struct mcux_pwt_config {
PWT_Type *base;
const struct device *clock_dev;
clock_control_subsys_t clock_subsys;
pwt_clock_source_t pwt_clock_source;
pwt_clock_prescale_t prescale;
void (*irq_config_func)(const struct device *dev);
};
struct mcux_pwt_data {
uint32_t clock_freq;
uint32_t period_cycles;
uint32_t high_overflows;
uint32_t low_overflows;
pwm_capture_callback_handler_t callback;
void *user_data;
pwt_config_t pwt_config;
bool continuous : 1;
bool inverted : 1;
bool overflowed : 1;
};
static inline bool mcux_pwt_is_active(const struct device *dev)
{
const struct mcux_pwt_config *config = dev->config;
return !!(config->base->CS & PWT_CS_PWTEN_MASK);
}
static int mcux_pwt_pin_set(const struct device *dev, uint32_t pwm,
uint32_t period_cycles, uint32_t pulse_cycles,
pwm_flags_t flags)
{
ARG_UNUSED(dev);
ARG_UNUSED(pwm);
ARG_UNUSED(period_cycles);
ARG_UNUSED(pulse_cycles);
ARG_UNUSED(flags);
LOG_ERR("pwt only supports pwm capture");
return -ENOTSUP;
}
static int mcux_pwt_pin_configure_capture(const struct device *dev,
uint32_t pwm,
pwm_flags_t flags,
pwm_capture_callback_handler_t cb,
void *user_data)
{
const struct mcux_pwt_config *config = dev->config;
struct mcux_pwt_data *data = dev->data;
if (pwm >= PWT_INPUTS) {
LOG_ERR("invalid channel %d", pwm);
return -EINVAL;
}
if (mcux_pwt_is_active(dev)) {
LOG_ERR("pwm capture in progress");
return -EBUSY;
}
data->callback = cb;
data->user_data = user_data;
data->pwt_config.inputSelect = pwm;
data->continuous =
(flags & PWM_CAPTURE_MODE_MASK) == PWM_CAPTURE_MODE_CONTINUOUS;
data->inverted =
(flags & PWM_POLARITY_MASK) == PWM_POLARITY_INVERTED;
PWT_Init(config->base, &data->pwt_config);
PWT_EnableInterrupts(config->base,
kPWT_PulseWidthReadyInterruptEnable |
kPWT_CounterOverflowInterruptEnable);
return 0;
}
static int mcux_pwt_pin_enable_capture(const struct device *dev, uint32_t pwm)
{
const struct mcux_pwt_config *config = dev->config;
struct mcux_pwt_data *data = dev->data;
if (pwm >= PWT_INPUTS) {
LOG_ERR("invalid channel %d", pwm);
return -EINVAL;
}
if (!data->callback) {
LOG_ERR("PWM capture not configured");
return -EINVAL;
}
if (mcux_pwt_is_active(dev)) {
LOG_ERR("PWM capture already enabled");
return -EBUSY;
}
data->overflowed = false;
data->high_overflows = 0;
data->low_overflows = 0;
PWT_StartTimer(config->base);
return 0;
}
static int mcux_pwt_pin_disable_capture(const struct device *dev, uint32_t pwm)
{
const struct mcux_pwt_config *config = dev->config;
if (pwm >= PWT_INPUTS) {
LOG_ERR("invalid channel %d", pwm);
return -EINVAL;
}
PWT_StopTimer(config->base);
return 0;
}
static int mcux_pwt_calc_period(uint16_t ppw, uint16_t npw,
uint32_t high_overflows,
uint32_t low_overflows,
uint32_t *result)
{
uint32_t period;
/* Calculate sum of overflow counters */
if (u32_add_overflow(high_overflows, low_overflows, &period)) {
return -ERANGE;
}
/* Calculate cycles from sum of overflow counters */
if (u32_mul_overflow(period, 0xFFFFU, &period)) {
return -ERANGE;
}
/* Add positive pulse width */
if (u32_add_overflow(period, ppw, &period)) {
return -ERANGE;
}
/* Add negative pulse width */
if (u32_add_overflow(period, npw, &period)) {
return -ERANGE;
}
*result = period;
return 0;
}
static int mcux_pwt_calc_pulse(uint16_t pw, uint32_t overflows,
uint32_t *result)
{
uint32_t pulse;
/* Calculate cycles from overflow counter */
if (u32_mul_overflow(overflows, 0xFFFFU, &pulse)) {
return -ERANGE;
}
/* Add pulse width */
if (u32_add_overflow(pulse, pw, &pulse)) {
return -ERANGE;
}
*result = pulse;
return 0;
}
static void mcux_pwt_isr(const struct device *dev)
{
const struct mcux_pwt_config *config = dev->config;
struct mcux_pwt_data *data = dev->data;
uint32_t period = 0;
uint32_t pulse = 0;
uint32_t flags;
uint16_t ppw;
uint16_t npw;
int err;
flags = PWT_GetStatusFlags(config->base);
if (flags & kPWT_CounterOverflowFlag) {
if (config->base->CR & PWT_CR_LVL_MASK) {
data->overflowed |= u32_add_overflow(1,
data->high_overflows, &data->high_overflows);
} else {
data->overflowed |= u32_add_overflow(1,
data->low_overflows, &data->low_overflows);
}
PWT_ClearStatusFlags(config->base, kPWT_CounterOverflowFlag);
}
if (flags & kPWT_PulseWidthValidFlag) {
ppw = PWT_ReadPositivePulseWidth(config->base);
npw = PWT_ReadNegativePulseWidth(config->base);
if (!data->continuous) {
PWT_StopTimer(config->base);
}
if (data->inverted) {
err = mcux_pwt_calc_pulse(npw, data->low_overflows,
&pulse);
} else {
err = mcux_pwt_calc_pulse(ppw, data->high_overflows,
&pulse);
}
if (err == 0) {
err = mcux_pwt_calc_period(ppw, npw,
data->high_overflows,
data->low_overflows,
&period);
}
if (data->overflowed) {
err = -ERANGE;
}
LOG_DBG("period = %d, pulse = %d, err = %d", period, pulse,
err);
if (data->callback) {
data->callback(dev, data->pwt_config.inputSelect,
period, pulse, err, data->user_data);
}
data->overflowed = false;
data->high_overflows = 0;
data->low_overflows = 0;
PWT_ClearStatusFlags(config->base, kPWT_PulseWidthValidFlag);
}
}
static int mcux_pwt_get_cycles_per_sec(const struct device *dev, uint32_t pwm,
uint64_t *cycles)
{
const struct mcux_pwt_config *config = dev->config;
struct mcux_pwt_data *data = dev->data;
ARG_UNUSED(pwm);
*cycles = data->clock_freq >> config->prescale;
return 0;
}
static int mcux_pwt_init(const struct device *dev)
{
const struct mcux_pwt_config *config = dev->config;
struct mcux_pwt_data *data = dev->data;
pwt_config_t *pwt_config = &data->pwt_config;
if (clock_control_get_rate(config->clock_dev, config->clock_subsys,
&data->clock_freq)) {
LOG_ERR("could not get clock frequency");
return -EINVAL;
}
PWT_GetDefaultConfig(pwt_config);
pwt_config->clockSource = config->pwt_clock_source;
pwt_config->prescale = config->prescale;
pwt_config->enableFirstCounterLoad = true;
PWT_Init(config->base, pwt_config);
config->irq_config_func(dev);
return 0;
}
static const struct pwm_driver_api mcux_pwt_driver_api = {
.pin_set = mcux_pwt_pin_set,
.get_cycles_per_sec = mcux_pwt_get_cycles_per_sec,
.pin_configure_capture = mcux_pwt_pin_configure_capture,
.pin_enable_capture = mcux_pwt_pin_enable_capture,
.pin_disable_capture = mcux_pwt_pin_disable_capture,
};
#define TO_PWT_PRESCALE_DIVIDE(val) _DO_CONCAT(kPWT_Prescale_Divide_, val)
#define PWT_DEVICE(n) \
static void mcux_pwt_config_func_##n(const struct device *dev); \
\
static const struct mcux_pwt_config mcux_pwt_config_##n = { \
.base = (PWT_Type *)DT_INST_REG_ADDR(n), \
.clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(n)), \
.clock_subsys = \
(clock_control_subsys_t)DT_INST_CLOCKS_CELL(n, name), \
.pwt_clock_source = kPWT_BusClock, \
.prescale = \
TO_PWT_PRESCALE_DIVIDE(DT_INST_PROP(n, prescaler)), \
.irq_config_func = mcux_pwt_config_func_##n, \
}; \
\
static struct mcux_pwt_data mcux_pwt_data_##n; \
\
DEVICE_DT_INST_DEFINE(n, &mcux_pwt_init, \
device_pm_control_nop, &mcux_pwt_data_##n, \
&mcux_pwt_config_##n, \
POST_KERNEL, \
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
&mcux_pwt_driver_api); \
\
static void mcux_pwt_config_func_##n(const struct device *dev) \
{ \
IRQ_CONNECT(DT_INST_IRQN(n), DT_INST_IRQ(n, priority), \
mcux_pwt_isr, DEVICE_DT_INST_GET(n), 0); \
irq_enable(DT_INST_IRQN(n)); \
}
DT_INST_FOREACH_STATUS_OKAY(PWT_DEVICE)