NXP driver: lptmr: add alarm and guard period API functions.

Add alarm APIs: set_alarm, cancel_alarm
Add guard period APIs: set_guard_period

Signed-off-by: Holt.Sun <[email protected]>

Author: Holt-Sun

drivers/counter/counter_mcux_lptmr.c

@@ -12,6 +12,8 @@
 #include <zephyr/irq.h>
 #include <fsl_lptmr.h>
 
+#define NUM_CHANNELS 1
+
 struct mcux_lptmr_config {
 	struct counter_config_info info;
 	LPTMR_Type *base;
@@ -22,11 +24,15 @@ struct mcux_lptmr_config {
 	lptmr_pin_select_t pin;
 	lptmr_pin_polarity_t polarity;
 	void (*irq_config_func)(const struct device *dev);
+	unsigned int irqn;
 };
 
 struct mcux_lptmr_data {
 	counter_top_callback_t top_callback;
+	counter_alarm_callback_t alarm_callback;
 	void *top_user_data;
+	void *alarm_user_data;
+	uint32_t guard_period;
 };
 
 static int mcux_lptmr_start(const struct device *dev)
@@ -118,11 +124,132 @@ static void mcux_lptmr_isr(const struct device *dev)
 	if (data->top_callback) {
 		data->top_callback(dev, data->top_user_data);
 	}
+
+	if (data->alarm_callback) {
+		uint32_t ticks;
+		ticks = LPTMR_GetCurrentTimerCount(config->base);
+		counter_alarm_callback_t alarm_callback = data->alarm_callback;
+		void *alarm_user_data = data->alarm_user_data;
+		data->alarm_callback = NULL;
+		data->alarm_user_data = NULL;
+		alarm_callback(dev, 0, ticks, alarm_user_data);
+	}
+}
+
+static int mcux_lptmr_set_guard_period(const struct device *dev, uint32_t guard, uint32_t flags)
+{
+	struct mcux_lptmr_data *data = dev->data;
+
+	ARG_UNUSED(flags);
+
+	__ASSERT_NO_MSG(guard < mcux_lptmr_get_top_value(dev));
+	data->guard_period = guard;
+
+	return 0;
+}
+
+static uint32_t mcux_lptmr_get_guard_period(const struct device *dev, uint32_t flags)
+{
+	struct mcux_lptmr_data *data = dev->data;
+
+	ARG_UNUSED(flags);
+
+	return data->guard_period;
+}
+
+static int mcux_lptmr_set_alarm(const struct device *dev, uint8_t chan_id,
+				const struct counter_alarm_cfg *alarm_cfg)
+{
+	const struct mcux_lptmr_config *config = dev->config;
+	struct mcux_lptmr_data *data = dev->data;
+	uint32_t current;
+	uint32_t max_rel_val;
+	bool irq_on_late = false;
+	uint32_t ticks = alarm_cfg->ticks;
+	bool absolute = alarm_cfg->flags & COUNTER_ALARM_CFG_ABSOLUTE;
+	int err = 0;
+	uint32_t top = mcux_lptmr_get_top_value(dev);
+
+	if (alarm_cfg->ticks > top) {
+		return -EINVAL;
+	}
+
+	if (chan_id != 0) {
+		return -EINVAL;
+	}
+
+	if (data->alarm_callback) {
+		return -EBUSY;
+	}
+
+	data->alarm_callback = alarm_cfg->callback;
+	data->alarm_user_data = alarm_cfg->user_data;
+
+	current = LPTMR_GetCurrentTimerCount(config->base);
+	max_rel_val = (current + data->guard_period) % config->info.max_top_value;
+
+	if (absolute == 0) {
+		/*
+		 * 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 CMP and CNT.
+		 *
+		 * Note that half of counter range is an arbitrary value.
+		 */
+		irq_on_late = ticks < (config->info.max_top_value / 2);
+		ticks = (ticks + current) % config->info.max_top_value;
+	} else {
+		irq_on_late = alarm_cfg->flags & COUNTER_ALARM_CFG_EXPIRE_WHEN_LATE;
+		ticks = alarm_cfg->ticks % config->info.max_top_value;
+	}
+
+	/*
+	 * When LPTMR is enabled, the CMR can be altered only when CSR[TCF] = 1, since this cannot
+	 * be guaranteed, the timer must be stopped before setting the CMR.
+	 */
+	LPTMR_StopTimer(config->base);
+
+	LPTMR_SetTimerPeriod(config->base, ticks);
+	LPTMR_EnableInterrupts(config->base, kLPTMR_TimerInterruptEnable);
+
+	LPTMR_StartTimer(config->base);
+
+	if (ticks <= max_rel_val) {
+		if (absolute) {
+			err = -ETIME;
+		}
+
+		if (irq_on_late) {
+			NVIC_SetPendingIRQ(config->irqn);
+		} else {
+			data->alarm_callback = NULL;
+		}
+	}
+
+	return err;
+}
+
+static int mcux_lptmr_cancel_alarm(const struct device *dev, uint8_t chan_id)
+{
+	const struct mcux_lptmr_config *config = dev->config;
+	struct mcux_lptmr_data *data = dev->data;
+
+	if (chan_id != 0) {
+		return -EINVAL;
+	}
+
+	LPTMR_DisableInterrupts(config->base, kLPTMR_TimerInterruptEnable);
+	data->alarm_callback = NULL;
+
+	return 0;
 }
 
 static int mcux_lptmr_init(const struct device *dev)
 {
 	const struct mcux_lptmr_config *config = dev->config;
+	struct mcux_lptmr_data *data = dev->data;
 	lptmr_config_t lptmr_config;
 
 	LPTMR_GetDefaultConfig(&lptmr_config);
@@ -143,6 +270,8 @@ static int mcux_lptmr_init(const struct device *dev)
 
 	config->irq_config_func(dev);
 
+	data->guard_period = 0;
+
 	return 0;
 }
 
@@ -153,6 +282,10 @@ static DEVICE_API(counter, mcux_lptmr_driver_api) = {
 	.set_top_value = mcux_lptmr_set_top_value,
 	.get_pending_int = mcux_lptmr_get_pending_int,
 	.get_top_value = mcux_lptmr_get_top_value,
+	.set_alarm = mcux_lptmr_set_alarm,
+	.cancel_alarm = mcux_lptmr_cancel_alarm,
+	.set_guard_period = mcux_lptmr_set_guard_period,
+	.get_guard_period = mcux_lptmr_get_guard_period,
 };
 
 #define COUNTER_MCUX_LPTMR_DEVICE_INIT(n)					\
@@ -181,7 +314,7 @@ static DEVICE_API(counter, mcux_lptmr_driver_api) = {
 			.freq = DT_INST_PROP(n, clock_frequency) /		\
 				DT_INST_PROP(n, prescaler),			\
 			.flags = COUNTER_CONFIG_INFO_COUNT_UP,			\
-			.channels = 0,						\
+			.channels = NUM_CHANNELS,                                          \
 		},								\
 		.base = (LPTMR_Type *)DT_INST_REG_ADDR(n),			\
 		.clk_source = DT_INST_PROP(n, clk_source),			\
@@ -193,6 +326,7 @@ static DEVICE_API(counter, mcux_lptmr_driver_api) = {
 		.prescaler_glitch = DT_INST_PROP(n, prescale_glitch_filter) +	\
 			DT_INST_PROP(n, timer_mode_sel) - 1,			\
 		.irq_config_func = mcux_lptmr_irq_config_##n,			\
+		.irqn = DT_INST_IRQN(n),                                \
 	};									\
 										\
 	DEVICE_DT_INST_DEFINE(n, &mcux_lptmr_init, NULL,			\
@@ -201,5 +335,4 @@ static DEVICE_API(counter, mcux_lptmr_driver_api) = {
 		POST_KERNEL, CONFIG_COUNTER_INIT_PRIORITY,			\
 		&mcux_lptmr_driver_api);
 
-
 DT_INST_FOREACH_STATUS_OKAY(COUNTER_MCUX_LPTMR_DEVICE_INIT)