drivers: pwm: sam4s: Add period and fault interrupts

The SAM4S pwm supports several interrupts. This commit
implements the interrupts when a channel period has ended
or a fault event has occured.

Signed-off-by: Jaro Van Landschoot <[email protected]>

Author: javlands

drivers/pwm/pwm_sam.c

@@ -12,6 +12,7 @@
 #include <zephyr/drivers/pwm.h>
 #include <zephyr/drivers/pinctrl.h>
 #include <zephyr/drivers/clock_control/atmel_sam_pmc.h>
+#include <zephyr/irq.h>
 
 #include <zephyr/logging/log.h>
 
@@ -35,10 +36,19 @@ struct sam_pwm_config {
 	const struct pinctrl_dev_config *pcfg;
 	uint8_t prescaler;
 	uint8_t divider;
+#ifdef CONFIG_PWM_INTERRUPT
+	void (*irq_config)(void);
+#endif /* CONFIG_PWM_INTERRUPT */
 };
 
-static int sam_pwm_get_cycles_per_sec(const struct device *dev,
-				      uint32_t channel, uint64_t *cycles)
+struct sam_pwm_data {
+#ifdef CONFIG_PWM_INTERRUPT
+	pwm_interrupt_callback_handler_t callback;
+	void *user_data;
+#endif /* CONFIG_PWM_INTERRUPT */
+};
+
+static int sam_pwm_get_cycles_per_sec(const struct device *dev, uint32_t channel, uint64_t *cycles)
 {
 	const struct sam_pwm_config *config = dev->config;
 	uint8_t prescaler = config->prescaler;
@@ -99,6 +109,88 @@ static int sam_pwm_set_cycles(const struct device *dev, uint32_t channel,
 	return 0;
 }
 
+#ifdef CONFIG_PWM_INTERRUPT
+static void sam_pwm_isr(const struct device *dev)
+{
+	const struct sam_pwm_config *config = dev->config;
+	struct sam_pwm_data *data = dev->data;
+	Pwm *const pwm = config->regs;
+	pwm_flags_t flags;
+
+	uint32_t status = pwm->PWM_ISR1;
+
+	if (data->callback == NULL) {
+		return;
+	}
+
+	for (uint32_t i = 0; i < PWMCH_NUM_NUMBER; i++) {
+		flags = 0;
+		if ((status & (PWM_ISR1_CHID0 << i)) != 0) {
+			flags |= PWM_INTERRUPT_TYPE_PERIOD;
+		}
+		if ((status & (PWM_ISR1_FCHID0 << i)) != 0) {
+			flags |= PWM_INTERRUPT_TYPE_FAULT;
+		}
+
+		if (flags > 0) {
+			data->callback(dev, i, flags, data->user_data);
+		}
+	}
+}
+
+static int sam_pwm_configure_interrupt(const struct device *dev,
+				       pwm_interrupt_callback_handler_t cb, void *user_data)
+{
+	struct sam_pwm_data *data = dev->data;
+
+	data->callback = cb;
+	data->user_data = user_data;
+
+	return 0;
+}
+
+static int sam_pwm_enable_interrupt(const struct device *dev, uint32_t channel, pwm_flags_t flags)
+{
+	const struct sam_pwm_config *config = dev->config;
+	uint32_t pwm_ier1 = 0;
+
+	Pwm *const pwm = config->regs;
+
+	/* Dummy read to clear status register*/
+	(void)pwm->PWM_ISR1;
+
+	if ((flags & PWM_INTERRUPT_TYPE_PERIOD) != 0) {
+		pwm_ier1 |= (PWM_ENA_CHID0 << channel);
+	}
+	if ((flags & PWM_INTERRUPT_TYPE_FAULT) != 0) {
+		pwm_ier1 |= (PWM_IER1_FCHID0 << channel);
+	}
+
+	pwm->PWM_IER1 = pwm_ier1;
+
+	return 0;
+}
+
+static int sam_pwm_disable_interrupt(const struct device *dev, uint32_t channel, pwm_flags_t flags)
+{
+	const struct sam_pwm_config *config = dev->config;
+	uint32_t pwm_idr1 = 0;
+
+	Pwm *const pwm = config->regs;
+
+	if ((flags & PWM_INTERRUPT_TYPE_PERIOD) != 0) {
+		pwm_idr1 |= (PWM_IDR1_CHID0 << channel);
+	}
+	if ((flags & PWM_INTERRUPT_TYPE_FAULT) != 0) {
+		pwm_idr1 |= (PWM_IDR1_FCHID0 << channel);
+	}
+
+	pwm->PWM_IDR1 = pwm_idr1;
+
+	return 0;
+}
+#endif /* CONFIG_PWM_INTERRUPT */
+
 static int sam_pwm_init(const struct device *dev)
 {
 	const struct sam_pwm_config *config = dev->config;
@@ -110,6 +202,10 @@ static int sam_pwm_init(const struct device *dev)
 
 	/* FIXME: way to validate prescaler & divider */
 
+#ifdef CONFIG_PWM_INTERRUPT
+	config->irq_config();
+#endif
+
 	/* Enable PWM clock in PMC */
 	(void)clock_control_on(SAM_DT_PMC_CONTROLLER,
 			       (clock_control_subsys_t)&config->clock_cfg);
@@ -128,23 +224,42 @@ static int sam_pwm_init(const struct device *dev)
 static DEVICE_API(pwm, sam_pwm_driver_api) = {
 	.set_cycles = sam_pwm_set_cycles,
 	.get_cycles_per_sec = sam_pwm_get_cycles_per_sec,
+#ifdef CONFIG_PWM_INTERRUPT
+	.configure_interrupt = sam_pwm_configure_interrupt,
+	.enable_interrupt = sam_pwm_enable_interrupt,
+	.disable_interrupt = sam_pwm_disable_interrupt,
+#endif /* CONFIG_PWM_INTERRUPT */
 };
 
+#define SAM_PWM_INTERRUPT_INIT(inst)					\
+	static void sam_pwm_irq_config_##inst(void)			\
+	{								\
+		IRQ_CONNECT(DT_INST_IRQN(inst), 0, sam_pwm_isr,		\
+			    DEVICE_DT_INST_GET(inst), 0);		\
+		irq_enable(DT_INST_IRQN(inst));				\
+	}
+
 #define SAM_INST_INIT(inst)						\
 	PINCTRL_DT_INST_DEFINE(inst);					\
+									\
+	IF_ENABLED(CONFIG_PWM_INTERRUPT, (SAM_PWM_INTERRUPT_INIT(inst)))\
+									\
 	static const struct sam_pwm_config sam_pwm_config_##inst = {	\
 		.regs = (Pwm *)DT_INST_REG_ADDR(inst),			\
 		.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst),		\
 		.clock_cfg = SAM_DT_INST_CLOCK_PMC_CFG(inst),		\
 		.prescaler = DT_INST_PROP(inst, prescaler),		\
 		.divider = DT_INST_PROP(inst, divider),			\
+		IF_ENABLED(CONFIG_PWM_INTERRUPT,			\
+			   (.irq_config = sam_pwm_irq_config_##inst,))	\
 	};								\
 									\
-	DEVICE_DT_INST_DEFINE(inst,					\
-			    &sam_pwm_init, NULL,			\
-			    NULL, &sam_pwm_config_##inst,		\
-			    POST_KERNEL,				\
-			    CONFIG_PWM_INIT_PRIORITY,			\
-			    &sam_pwm_driver_api);
+	static struct sam_pwm_data sam_pwm_data_##inst;			\
+									\
+	DEVICE_DT_INST_DEFINE(inst, &sam_pwm_init, NULL,		\
+			      &sam_pwm_data_##inst,			\
+			      &sam_pwm_config_##inst, POST_KERNEL,	\
+			      CONFIG_PWM_INIT_PRIORITY,			\
+			      &sam_pwm_driver_api);
 
 DT_INST_FOREACH_STATUS_OKAY(SAM_INST_INIT)