drivers: pwm: always use nanoseconds for set

In order to be consistent with what is possible in Devicetree, always
take a period in nanoseconds. Other scales or units may be specified by
using, e.g., the PWM_MSEC() macros (all of them converting down to
nanoseconds). This change then deletes the "_nsec" and "_usec" versions
of the pwm_set call.

Note that this change limits the period to UINT32_MAX nanoseconds,
~4.3s. PWM is, in generali, used with periods below the second so it
should not be a problem.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

drivers/led/led_pwm.c

@@ -49,7 +49,7 @@ static int led_pwm_blink(const struct device *dev, uint32_t led,
 
 	dt_led = &config->led[led];
 
-	return pwm_set_usec_dt(dt_led, period_usec, pulse_usec);
+	return pwm_set_dt(dt_led, PWM_USEC(period_usec), PWM_USEC(pulse_usec));
 }
 
 static int led_pwm_set_brightness(const struct device *dev,
@@ -64,8 +64,8 @@ static int led_pwm_set_brightness(const struct device *dev,
 
 	dt_led = &config->led[led];
 
-	return pwm_set_nsec_pulse_dt(&config->led[led],
-				     dt_led->period * value / 100);
+	return pwm_set_pulse_dt(&config->led[led],
+				dt_led->period * value / 100);
 }
 
 static int led_pwm_on(const struct device *dev, uint32_t led)

include/zephyr/drivers/pwm.h

@@ -417,100 +417,12 @@ static inline int z_impl_pwm_get_cycles_per_sec(const struct device *dev,
 	return api->get_cycles_per_sec(dev, channel, cycles);
 }
 
-/**
- * @brief Set the period and pulse width in microseconds for a single PWM
- *        output.
- *
- * @param[in] dev PWM device instance.
- * @param channel PWM channel.
- * @param period Period (in microseconds) set to the PWM.
- * @param pulse Pulse width (in microseconds) set to the PWM.
- * @param flags Flags for pin configuration (polarity).
- *
- * @retval 0 If successful.
- * @retval -ENOTSUP If requested period or pulse cycles are not supported.
- * @retval -errno Other negative errno code on failure.
- */
-static inline int pwm_set_usec(const struct device *dev, uint32_t channel,
-			       uint32_t period, uint32_t pulse,
-			       pwm_flags_t flags)
-{
-	int err;
-	uint64_t pulse_cycles;
-	uint64_t period_cycles;
-	uint64_t cycles_per_sec;
-
-	err = pwm_get_cycles_per_sec(dev, channel, &cycles_per_sec);
-	if (err < 0) {
-		return err;
-	}
-
-	period_cycles = (period * cycles_per_sec) / USEC_PER_SEC;
-	if (period_cycles > UINT32_MAX) {
-		return -ENOTSUP;
-	}
-
-	pulse_cycles = (pulse * cycles_per_sec) / USEC_PER_SEC;
-	if (pulse_cycles > UINT32_MAX) {
-		return -ENOTSUP;
-	}
-
-	return pwm_set_cycles(dev, channel, (uint32_t)period_cycles,
-			      (uint32_t)pulse_cycles, flags);
-}
-
-/**
- * @brief Set the period and pulse width in microseconds from a struct
- *        pwm_dt_spec (with custom period).
- *
- * This is equivalent to:
- *
- *     pwm_set_usec(spec->dev, spec->channel, period, pulse, spec->flags)
- *
- * The period specified in @p spec is ignored. This API call can be used when
- * the period specified in Devicetree needs to be changed at runtime.
- *
- * @param[in] spec PWM specification from devicetree.
- * @param period Period (in microseconds) set to the PWM.
- * @param pulse Pulse width (in microseconds) set to the PWM.
- *
- * @return A value from pwm_set_usec().
- *
- * @see pwm_set_usec_pulse_dt()
- */
-static inline int pwm_set_usec_dt(const struct pwm_dt_spec *spec,
-				  uint32_t period, uint32_t pulse)
-{
-	return pwm_set_usec(spec->dev, spec->channel, period, pulse,
-			    spec->flags);
-}
-
-/**
- * @brief Set the period and pulse width in microseconds from a struct
- *        pwm_dt_spec.
- *
- * This is equivalent to:
- *
- *     pwm_set_usec(spec->dev, spec->channel, spec->period / NSEC_PER_USEC,
- *                  pulse, spec->flags)
- *
- * @param[in] spec PWM specification from devicetree.
- * @param pulse Pulse width (in microseconds) set to the PWM.
- *
- * @return A value from pwm_set_usec().
- *
- * @see pwm_set_usec_dt()
- */
-static inline int pwm_set_usec_pulse_dt(const struct pwm_dt_spec *spec,
-					uint32_t pulse)
-{
-	return pwm_set_usec(spec->dev, spec->channel,
-			    spec->period / NSEC_PER_USEC, pulse, spec->flags);
-}
-
 /**
  * @brief Set the period and pulse width in nanoseconds for a single PWM output.
  *
+ * @note Utility macros such as PWM_MSEC() can be used to convert from other
+ * scales or units to nanoseconds, the units used by this function.
+ *
  * @param[in] dev PWM device instance.
  * @param channel PWM channel.
  * @param period Period (in nanoseconds) set to the PWM.
@@ -521,9 +433,8 @@ static inline int pwm_set_usec_pulse_dt(const struct pwm_dt_spec *spec,
  * @retval -ENOTSUP If requested period or pulse cycles are not supported.
  * @retval -errno Other negative errno code on failure.
  */
-static inline int pwm_set_nsec(const struct device *dev, uint32_t channel,
-			       uint32_t period, uint32_t pulse,
-			       pwm_flags_t flags)
+static inline int pwm_set(const struct device *dev, uint32_t channel,
+			  uint32_t period, uint32_t pulse, pwm_flags_t flags)
 {
 	int err;
 	uint64_t pulse_cycles;
@@ -555,7 +466,7 @@ static inline int pwm_set_nsec(const struct device *dev, uint32_t channel,
  *
  * This is equivalent to:
  *
- *     pwm_set_nsec(spec->dev, spec->channel, period, pulse, spec->flags)
+ *     pwm_set(spec->dev, spec->channel, period, pulse, spec->flags)
  *
  * The period specified in @p spec is ignored. This API call can be used when
  * the period specified in Devicetree needs to be changed at runtime.
@@ -564,15 +475,14 @@ static inline int pwm_set_nsec(const struct device *dev, uint32_t channel,
  * @param period Period (in nanoseconds) set to the PWM.
  * @param pulse Pulse width (in nanoseconds) set to the PWM.
  *
- * @return A value from pwm_set_nsec().
+ * @return A value from pwm_set().
  *
- * @see pwm_set_nsec_pulse_dt()
+ * @see pwm_set_pulse_dt()
  */
-static inline int pwm_set_nsec_dt(const struct pwm_dt_spec *spec,
-				  uint32_t period, uint32_t pulse)
+static inline int pwm_set_dt(const struct pwm_dt_spec *spec, uint32_t period,
+			     uint32_t pulse)
 {
-	return pwm_set_nsec(spec->dev, spec->channel, period, pulse,
-			    spec->flags);
+	return pwm_set(spec->dev, spec->channel, period, pulse, spec->flags);
 }
 
 /**
@@ -581,20 +491,20 @@ static inline int pwm_set_nsec_dt(const struct pwm_dt_spec *spec,
  *
  * This is equivalent to:
  *
- *     pwm_set_nsec(spec->dev, spec->channel, spec->period, pulse, spec->flags)
+ *     pwm_set(spec->dev, spec->channel, spec->period, pulse, spec->flags)
  *
  * @param[in] spec PWM specification from devicetree.
  * @param pulse Pulse width (in nanoseconds) set to the PWM.
  *
- * @return A value from pwm_set_nsec().
+ * @return A value from pwm_set().
  *
- * @see pwm_set_nsec_pulse_dt()
+ * @see pwm_set_pulse_dt()
  */
-static inline int pwm_set_nsec_pulse_dt(const struct pwm_dt_spec *spec,
-					uint32_t pulse)
+static inline int pwm_set_pulse_dt(const struct pwm_dt_spec *spec,
+				   uint32_t pulse)
 {
-	return pwm_set_nsec(spec->dev, spec->channel, spec->period, pulse,
-			    spec->flags);
+	return pwm_set(spec->dev, spec->channel, spec->period, pulse,
+		       spec->flags);
 }
 
 /**
@@ -934,26 +844,27 @@ pwm_pin_set_cycles(const struct device *dev, uint32_t channel, uint32_t period,
 
 /**
  * @brief Set the period and pulse width for a single PWM output.
- * @deprecated Use pwm_set_usec() instead.
+ * @deprecated Use pwm_set() with PWM_USEC() instead.
  */
 __deprecated static inline int pwm_pin_set_usec(const struct device *dev,
 						uint32_t channel,
 						uint32_t period, uint32_t pulse,
 						pwm_flags_t flags)
 {
-	return pwm_set_usec(dev, channel, period, pulse, flags);
+	return pwm_set(dev, channel, period * NSEC_PER_USEC,
+		       pulse * NSEC_PER_USEC, flags);
 }
 
 /**
  * @brief Set the period and pulse width for a single PWM output.
- * @deprecated Use pwm_set_nsec() instead.
+ * @deprecated Use pwm_set() instead.
  */
 __deprecated static inline int pwm_pin_set_nsec(const struct device *dev,
 						uint32_t channel,
 						uint32_t period, uint32_t pulse,
 						pwm_flags_t flags)
 {
-	return pwm_set_nsec(dev, channel, period, pulse, flags);
+	return pwm_set(dev, channel, period, pulse, flags);
 }
 
 /**

include/zephyr/dt-bindings/pwm/pwm.h

@@ -30,9 +30,8 @@
 
 /**
  * @name PWM polarity flags
- * The `PWM_POLARITY_*` flags are used with pwm_set_cycles(), pwm_set_usec(),
- * pwm_set_nsec() or pwm_configure_capture() to specify the polarity of a PWM
- * channel.
+ * The `PWM_POLARITY_*` flags are used with pwm_set_cycles(), pwm_set()
+ * or pwm_configure_capture() to specify the polarity of a PWM channel.
  *
  * The flags are on the lower 8bits of the pwm_flags_t
  * @{

samples/basic/blinky_pwm/src/main.c

@@ -43,7 +43,7 @@ void main(void)
 	 */
 	printk("Calibrating for channel %d...\n", pwm_led0.channel);
 	max_period = MAX_PERIOD;
-	while (pwm_set_nsec_dt(&pwm_led0, max_period, max_period / 2U)) {
+	while (pwm_set_dt(&pwm_led0, max_period, max_period / 2U)) {
 		max_period /= 2U;
 		if (max_period < (4U * MIN_PERIOD)) {
 			printk("Error: PWM device "
@@ -58,7 +58,7 @@ void main(void)
 
 	period = max_period;
 	while (1) {
-		ret = pwm_set_nsec_dt(&pwm_led0, period, period / 2U);
+		ret = pwm_set_dt(&pwm_led0, period, period / 2U);
 		if (ret) {
 			printk("Error %d: failed to set pulse width\n", ret);
 			return;

samples/basic/fade_led/src/main.c

@@ -35,7 +35,7 @@ void main(void)
 	}
 
 	while (1) {
-		ret = pwm_set_nsec_pulse_dt(&pwm_led0, pulse_width);
+		ret = pwm_set_pulse_dt(&pwm_led0, pulse_width);
 		if (ret) {
 			printk("Error %d: failed to set pulse width\n", ret);
 			return;

samples/basic/rgb_led/src/main.c

@@ -39,7 +39,7 @@ void main(void)
 	while (1) {
 		for (pulse_red = 0U; pulse_red <= red_pwm_led.period;
 		     pulse_red += STEP_SIZE) {
-			ret = pwm_set_nsec_pulse_dt(&red_pwm_led, pulse_red);
+			ret = pwm_set_pulse_dt(&red_pwm_led, pulse_red);
 			if (ret != 0) {
 				printk("Error %d: red write failed\n", ret);
 				return;
@@ -48,8 +48,8 @@ void main(void)
 			for (pulse_green = 0U;
 			     pulse_green <= green_pwm_led.period;
 			     pulse_green += STEP_SIZE) {
-				ret = pwm_set_nsec_pulse_dt(&green_pwm_led,
-							    pulse_green);
+				ret = pwm_set_pulse_dt(&green_pwm_led,
+						       pulse_green);
 				if (ret != 0) {
 					printk("Error %d: green write failed\n",
 					       ret);
@@ -59,8 +59,8 @@ void main(void)
 				for (pulse_blue = 0U;
 				     pulse_blue <= blue_pwm_led.period;
 				     pulse_blue += STEP_SIZE) {
-					ret = pwm_set_nsec_pulse_dt(
-						&blue_pwm_led, pulse_blue);
+					ret = pwm_set_pulse_dt(&blue_pwm_led,
+							       pulse_blue);
 					if (ret != 0) {
 						printk("Error %d: "
 						       "blue write failed\n",

samples/basic/servo_motor/src/main.c

@@ -38,7 +38,7 @@ void main(void)
 	}
 
 	while (1) {
-		ret = pwm_set_nsec_pulse_dt(&servo, pulse_width);
+		ret = pwm_set_pulse_dt(&servo, pulse_width);
 		if (ret < 0) {
 			printk("Error %d: failed to set pulse width\n", ret);
 			return;

samples/bluetooth/mesh_demo/src/microbit.c

@@ -129,13 +129,14 @@ void board_play_tune(const char *str)
 		}
 
 		if (period) {
-			pwm_set_usec(pwm, BUZZER_PWM_CHANNEL, period, period / 2U, 0);
+			pwm_set(pwm, BUZZER_PWM_CHANNEL, PWM_USEC(period),
+				PWM_USEC(period) / 2U, 0);
 		}
 
 		k_sleep(K_MSEC(duration));
 
 		/* Disable the PWM */
-		pwm_set_usec(pwm, BUZZER_PWM_CHANNEL, 0, 0, 0);
+		pwm_set(pwm, BUZZER_PWM_CHANNEL, 0, 0, 0);
 	}
 }
 

samples/boards/bbc_microbit/pong/src/main.c

@@ -120,7 +120,7 @@ static enum sound_state {
 
 static inline void beep(int period)
 {
-	pwm_set_usec(pwm, SOUND_PWM_CHANNEL, period, period / 2, 0);
+	pwm_set(pwm, SOUND_PWM_CHANNEL, PWM_USEC(period), PWM_USEC(period) / 2, 0);
 }
 
 static void sound_set(enum sound_state state)

samples/boards/bbc_microbit/sound/src/main.c

@@ -33,11 +33,11 @@ static void beep(struct k_work *work)
 	/* The "period / 2" pulse duration gives 50% duty cycle, which
 	 * should result in the maximum sound volume.
 	 */
-	pwm_set_usec(pwm, BUZZER_PWM_CHANNEL, period, period / 2U, 0);
+	pwm_set(pwm, BUZZER_PWM_CHANNEL, PWM_USEC(period), PWM_USEC(period) / 2U, 0);
 	k_sleep(BEEP_DURATION);
 
 	/* Disable the PWM */
-	pwm_set_usec(pwm, BUZZER_PWM_CHANNEL, 0, 0, 0);
+	pwm_set(pwm, BUZZER_PWM_CHANNEL, 0, 0, 0);
 
 	/* Ensure there's a clear silent period between two tones */
 	k_sleep(K_MSEC(50));