zephyr/drivers/counter/counter_nrfx_timer.c

451 lines
12 KiB
C

/*
* Copyright (c) 2017 - 2018, Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/counter.h>
#include <hal/nrf_timer.h>
#include <sys/atomic.h>
#define LOG_LEVEL CONFIG_COUNTER_LOG_LEVEL
#define LOG_MODULE_NAME counter_timer
#include <logging/log.h>
LOG_MODULE_REGISTER(LOG_MODULE_NAME, LOG_LEVEL);
#define TIMER_CLOCK 16000000
#define CC_TO_ID(cc_num) (cc_num - 2)
#define ID_TO_CC(idx) (nrf_timer_cc_channel_t)(idx + 2)
#define TOP_CH NRF_TIMER_CC_CHANNEL0
#define COUNTER_TOP_EVT NRF_TIMER_EVENT_COMPARE0
#define COUNTER_TOP_INT_MASK NRF_TIMER_INT_COMPARE0_MASK
#define COUNTER_OVERFLOW_SHORT NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK
#define COUNTER_READ_CC NRF_TIMER_CC_CHANNEL1
struct counter_nrfx_data {
counter_top_callback_t top_cb;
void *top_user_data;
uint32_t guard_period;
atomic_t cc_int_pending;
};
struct counter_nrfx_ch_data {
counter_alarm_callback_t callback;
void *user_data;
};
struct counter_nrfx_config {
struct counter_config_info info;
struct counter_nrfx_ch_data *ch_data;
NRF_TIMER_Type *timer;
LOG_INSTANCE_PTR_DECLARE(log);
};
struct counter_timer_config {
nrf_timer_bit_width_t bit_width;
nrf_timer_mode_t mode;
nrf_timer_frequency_t freq;
};
static inline struct counter_nrfx_data *get_dev_data(const struct device *dev)
{
return dev->data;
}
static inline const struct counter_nrfx_config *get_nrfx_config(const struct device *dev)
{
return CONTAINER_OF(dev->config,
struct counter_nrfx_config, info);
}
static int start(const struct device *dev)
{
nrf_timer_task_trigger(get_nrfx_config(dev)->timer,
NRF_TIMER_TASK_START);
return 0;
}
static int stop(const struct device *dev)
{
nrf_timer_task_trigger(get_nrfx_config(dev)->timer,
NRF_TIMER_TASK_SHUTDOWN);
return 0;
}
static uint32_t get_top_value(const struct device *dev)
{
return nrf_timer_cc_get(get_nrfx_config(dev)->timer, TOP_CH);
}
static uint32_t read(const struct device *dev)
{
NRF_TIMER_Type *timer = get_nrfx_config(dev)->timer;
nrf_timer_task_trigger(timer,
nrf_timer_capture_task_get(COUNTER_READ_CC));
return nrf_timer_cc_get(timer, COUNTER_READ_CC);
}
static int get_value(const struct device *dev, uint32_t *ticks)
{
*ticks = read(dev);
return 0;
}
/* Return true if value equals 2^n - 1 */
static inline bool is_bit_mask(uint32_t val)
{
return !(val & (val + 1));
}
static uint32_t ticks_add(uint32_t val1, uint32_t val2, uint32_t top)
{
uint32_t to_top;
if (likely(is_bit_mask(top))) {
return (val1 + val2) & top;
}
to_top = top - val1;
return (val2 <= to_top) ? val1 + val2 : val2 - to_top;
}
static uint32_t ticks_sub(uint32_t val, uint32_t old, uint32_t top)
{
if (likely(is_bit_mask(top))) {
return (val - old) & top;
}
/* if top is not 2^n-1 */
return (val >= old) ? (val - old) : val + top + 1 - old;
}
static void set_cc_int_pending(const struct device *dev, uint8_t chan)
{
atomic_or(&get_dev_data(dev)->cc_int_pending, BIT(chan));
NRFX_IRQ_PENDING_SET(NRFX_IRQ_NUMBER_GET(get_nrfx_config(dev)->timer));
}
static int set_cc(const struct device *dev, uint8_t id, uint32_t val,
uint32_t flags)
{
__ASSERT_NO_MSG(get_dev_data(dev)->guard_period < get_top_value(dev));
bool absolute = flags & COUNTER_ALARM_CFG_ABSOLUTE;
bool irq_on_late;
NRF_TIMER_Type *reg = get_nrfx_config(dev)->timer;
uint8_t chan = ID_TO_CC(id);
nrf_timer_event_t evt = nrf_timer_compare_event_get(chan);
uint32_t top = get_top_value(dev);
int err = 0;
uint32_t prev_val;
uint32_t now;
uint32_t diff;
uint32_t max_rel_val;
__ASSERT(nrf_timer_int_enable_check(reg,
nrf_timer_compare_int_get(chan)) == 0,
"Expected that CC interrupt is disabled.");
/* First take care of a risk of an event coming from CC being set to
* next tick. Reconfigure CC to future (now tick is the furtherest
* future).
*/
now = read(dev);
prev_val = nrf_timer_cc_get(reg, chan);
nrf_timer_cc_set(reg, chan, now);
nrf_timer_event_clear(reg, evt);
if (absolute) {
max_rel_val = top - get_dev_data(dev)->guard_period;
irq_on_late = flags & COUNTER_ALARM_CFG_EXPIRE_WHEN_LATE;
} else {
/* If relative value is smaller than half of the counter range
* it is assumed that there is a risk of setting value too late
* and late detection algorithm must be applied. When late
* setting is detected, interrupt shall be triggered for
* immediate expiration of the timer. Detection is performed
* by limiting relative distance between CC and counter.
*
* Note that half of counter range is an arbitrary value.
*/
irq_on_late = val < (top / 2);
/* limit max to detect short relative being set too late. */
max_rel_val = irq_on_late ? top / 2 : top;
val = ticks_add(now, val, top);
}
nrf_timer_cc_set(reg, chan, val);
/* decrement value to detect also case when val == read(dev). Otherwise,
* condition would need to include comparing diff against 0.
*/
diff = ticks_sub(val - 1, read(dev), top);
if (diff > max_rel_val) {
if (absolute) {
err = -ETIME;
}
/* Interrupt is triggered always for relative alarm and
* for absolute depending on the flag.
*/
if (irq_on_late) {
set_cc_int_pending(dev, chan);
} else {
get_nrfx_config(dev)->ch_data[id].callback = NULL;
}
} else {
nrf_timer_int_enable(reg, nrf_timer_compare_int_get(chan));
}
return err;
}
static int set_alarm(const struct device *dev, uint8_t chan,
const struct counter_alarm_cfg *alarm_cfg)
{
const struct counter_nrfx_config *nrfx_config = get_nrfx_config(dev);
struct counter_nrfx_ch_data *chdata = &nrfx_config->ch_data[chan];
if (alarm_cfg->ticks > get_top_value(dev)) {
return -EINVAL;
}
if (chdata->callback) {
return -EBUSY;
}
chdata->callback = alarm_cfg->callback;
chdata->user_data = alarm_cfg->user_data;
return set_cc(dev, chan, alarm_cfg->ticks, alarm_cfg->flags);
}
static int cancel_alarm(const struct device *dev, uint8_t chan_id)
{
const struct counter_nrfx_config *config = get_nrfx_config(dev);
uint32_t int_mask = nrf_timer_compare_int_get(ID_TO_CC(chan_id));
nrf_timer_int_disable(config->timer, int_mask);
config->ch_data[chan_id].callback = NULL;
return 0;
}
static int set_top_value(const struct device *dev,
const struct counter_top_cfg *cfg)
{
const struct counter_nrfx_config *nrfx_config = get_nrfx_config(dev);
NRF_TIMER_Type *timer = get_nrfx_config(dev)->timer;
struct counter_nrfx_data *data = get_dev_data(dev);
int err = 0;
for (int i = 0; i < counter_get_num_of_channels(dev); i++) {
/* Overflow can be changed only when all alarms are
* disables.
*/
if (nrfx_config->ch_data[i].callback) {
return -EBUSY;
}
}
nrf_timer_int_disable(timer, COUNTER_TOP_INT_MASK);
nrf_timer_cc_set(timer, TOP_CH, cfg->ticks);
nrf_timer_shorts_enable(timer, COUNTER_OVERFLOW_SHORT);
data->top_cb = cfg->callback;
data->top_user_data = cfg->user_data;
if (!(cfg->flags & COUNTER_TOP_CFG_DONT_RESET)) {
nrf_timer_task_trigger(timer, NRF_TIMER_TASK_CLEAR);
} else if (read(dev) >= cfg->ticks) {
err = -ETIME;
if (cfg->flags & COUNTER_TOP_CFG_RESET_WHEN_LATE) {
nrf_timer_task_trigger(timer, NRF_TIMER_TASK_CLEAR);
}
}
if (cfg->callback) {
nrf_timer_int_enable(timer, COUNTER_TOP_INT_MASK);
}
return err;
}
static uint32_t get_pending_int(const struct device *dev)
{
return 0;
}
static int init_timer(const struct device *dev,
const struct counter_timer_config *config)
{
NRF_TIMER_Type *reg = get_nrfx_config(dev)->timer;
nrf_timer_bit_width_set(reg, config->bit_width);
nrf_timer_mode_set(reg, config->mode);
nrf_timer_frequency_set(reg, config->freq);
nrf_timer_cc_set(reg, TOP_CH, counter_get_max_top_value(dev));
NRFX_IRQ_ENABLE(NRFX_IRQ_NUMBER_GET(reg));
return 0;
}
static uint32_t get_guard_period(const struct device *dev, uint32_t flags)
{
return get_dev_data(dev)->guard_period;
}
static int set_guard_period(const struct device *dev, uint32_t guard,
uint32_t flags)
{
__ASSERT_NO_MSG(guard < get_top_value(dev));
get_dev_data(dev)->guard_period = guard;
return 0;
}
static void top_irq_handle(const struct device *dev)
{
NRF_TIMER_Type *reg = get_nrfx_config(dev)->timer;
counter_top_callback_t cb = get_dev_data(dev)->top_cb;
if (nrf_timer_event_check(reg, COUNTER_TOP_EVT) &&
nrf_timer_int_enable_check(reg, COUNTER_TOP_INT_MASK)) {
nrf_timer_event_clear(reg, COUNTER_TOP_EVT);
__ASSERT(cb != NULL, "top event enabled - expecting callback");
cb(dev, get_dev_data(dev)->top_user_data);
}
}
static void alarm_irq_handle(const struct device *dev, uint32_t id)
{
uint32_t cc = ID_TO_CC(id);
NRF_TIMER_Type *reg = get_nrfx_config(dev)->timer;
uint32_t int_mask = nrf_timer_compare_int_get(cc);
nrf_timer_event_t evt = nrf_timer_compare_event_get(cc);
bool hw_irq_pending = nrf_timer_event_check(reg, evt) &&
nrf_timer_int_enable_check(reg, int_mask);
bool sw_irq_pending = get_dev_data(dev)->cc_int_pending & BIT(cc);
if (hw_irq_pending || sw_irq_pending) {
struct counter_nrfx_ch_data *chdata;
counter_alarm_callback_t cb;
nrf_timer_event_clear(reg, evt);
atomic_and(&get_dev_data(dev)->cc_int_pending, ~BIT(cc));
nrf_timer_int_disable(reg, int_mask);
chdata = &get_nrfx_config(dev)->ch_data[id];
cb = chdata->callback;
chdata->callback = NULL;
if (cb) {
uint32_t cc_val = nrf_timer_cc_get(reg, cc);
cb(dev, id, cc_val, chdata->user_data);
}
}
}
static void irq_handler(const struct device *dev)
{
top_irq_handle(dev);
for (uint32_t i = 0; i < counter_get_num_of_channels(dev); i++) {
alarm_irq_handle(dev, i);
}
}
static const struct counter_driver_api counter_nrfx_driver_api = {
.start = start,
.stop = stop,
.get_value = get_value,
.set_alarm = set_alarm,
.cancel_alarm = cancel_alarm,
.set_top_value = set_top_value,
.get_pending_int = get_pending_int,
.get_top_value = get_top_value,
.get_guard_period = get_guard_period,
.set_guard_period = set_guard_period,
};
/*
* Device instantiation is done with node labels due to HAL API
* requirements. In particular, TIMERx_MAX_SIZE values from HALs
* are indexed by peripheral number, so DT_INST APIs won't work.
*/
#define TIMER(idx) DT_NODELABEL(timer##idx)
#define TIMER_PROP(idx, prop) DT_PROP(TIMER(idx), prop)
#define COUNTER_NRFX_TIMER_DEVICE(idx) \
BUILD_ASSERT(TIMER_PROP(idx, prescaler) <= \
TIMER_PRESCALER_PRESCALER_Msk, \
"TIMER prescaler out of range"); \
static int counter_##idx##_init(const struct device *dev) \
{ \
IRQ_CONNECT(DT_IRQN(TIMER(idx)), DT_IRQ(TIMER(idx), priority), \
irq_handler, DEVICE_DT_GET(TIMER(idx)), 0); \
static const struct counter_timer_config config = { \
.freq = TIMER_PROP(idx, prescaler), \
.mode = NRF_TIMER_MODE_TIMER, \
.bit_width = (TIMER##idx##_MAX_SIZE == 32) ? \
NRF_TIMER_BIT_WIDTH_32 : \
NRF_TIMER_BIT_WIDTH_16, \
}; \
return init_timer(dev, &config); \
} \
static struct counter_nrfx_data counter_##idx##_data; \
static struct counter_nrfx_ch_data \
counter##idx##_ch_data[CC_TO_ID(TIMER##idx##_CC_NUM)]; \
LOG_INSTANCE_REGISTER(LOG_MODULE_NAME, idx, CONFIG_COUNTER_LOG_LEVEL); \
static const struct counter_nrfx_config nrfx_counter_##idx##_config = {\
.info = { \
.max_top_value = (TIMER##idx##_MAX_SIZE == 32) ? \
0xffffffff : 0x0000ffff, \
.freq = TIMER_CLOCK / \
(1 << TIMER_PROP(idx, prescaler)), \
.flags = COUNTER_CONFIG_INFO_COUNT_UP, \
.channels = CC_TO_ID(TIMER##idx##_CC_NUM), \
}, \
.ch_data = counter##idx##_ch_data, \
.timer = (NRF_TIMER_Type *)DT_REG_ADDR(TIMER(idx)), \
LOG_INSTANCE_PTR_INIT(log, LOG_MODULE_NAME, idx) \
}; \
DEVICE_DT_DEFINE(TIMER(idx), \
counter_##idx##_init, \
NULL, \
&counter_##idx##_data, \
&nrfx_counter_##idx##_config.info, \
PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
&counter_nrfx_driver_api)
#ifdef CONFIG_COUNTER_TIMER0
COUNTER_NRFX_TIMER_DEVICE(0);
#endif
#ifdef CONFIG_COUNTER_TIMER1
COUNTER_NRFX_TIMER_DEVICE(1);
#endif
#ifdef CONFIG_COUNTER_TIMER2
COUNTER_NRFX_TIMER_DEVICE(2);
#endif
#ifdef CONFIG_COUNTER_TIMER3
COUNTER_NRFX_TIMER_DEVICE(3);
#endif
#ifdef CONFIG_COUNTER_TIMER4
COUNTER_NRFX_TIMER_DEVICE(4);
#endif