drivers: pwm: return -ENOTSUP if inactive level is not supported

The API spec states that calling pin_set() with period set to 0 is
equivalent to set the PWM channel to an inactive level. Some drivers
treat this input as invalid (-EINVAL), however, it's an unsupported
feature. Maybe it's due to copy&paste effect? This changes error message
to be clear and changes return value to -ENOTSUP for this case.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

drivers/pwm/pwm_imx.c

@@ -61,9 +61,8 @@ static int imx_pwm_pin_set(const struct device *dev, uint32_t pwm,
 
 
 	if (period_cycles == 0U) {
-		LOG_ERR("Invalid combination: period_cycles=%d, "
-			    "pulse_cycles=%d", period_cycles, pulse_cycles);
-		return -EINVAL;
+		LOG_ERR("Channel can not be set to inactive level");
+		return -ENOTSUP;
 	}
 
 	if (flags) {

drivers/pwm/pwm_mcux.c

@@ -53,9 +53,8 @@ static int mcux_pwm_pin_set(const struct device *dev, uint32_t pwm,
 	}
 
 	if (period_cycles == 0) {
-		LOG_ERR("Invalid combination: period_cycles=%u, "
-			"pulse_cycles=%u", period_cycles, pulse_cycles);
-		return -EINVAL;
+		LOG_ERR("Channel can not be set to inactive level");
+		return -ENOTSUP;
 	}
 
 	if (period_cycles > UINT16_MAX) {

drivers/pwm/pwm_mcux_ftm.c

@@ -71,9 +71,8 @@ static int mcux_ftm_pin_set(const struct device *dev, uint32_t pwm,
 #endif /* CONFIG_PWM_CAPTURE */
 
 	if (period_cycles == 0U) {
-		LOG_ERR("Invalid combination: period_cycles=%d, "
-			    "pulse_cycles=%d", period_cycles, pulse_cycles);
-		return -EINVAL;
+		LOG_ERR("Channel can not be set to inactive level");
+		return -ENOTSUP;
 	}
 
 	if (pwm >= config->channel_count) {

drivers/pwm/pwm_mcux_sctimer.c

@@ -49,9 +49,8 @@ static int mcux_sctimer_pwm_pin_set(const struct device *dev, uint32_t pwm,
 	}
 
 	if (period_cycles == 0) {
-		LOG_ERR("Invalid combination: period_cycles=%u, "
-			"pulse_cycles=%u", period_cycles, pulse_cycles);
-		return -EINVAL;
+		LOG_ERR("Channel can not be set to inactive level");
+		return -ENOTSUP;
 	}
 
 	if ((flags & PWM_POLARITY_INVERTED) == 0) {

drivers/pwm/pwm_mcux_tpm.c

@@ -50,9 +50,8 @@ static int mcux_tpm_pin_set(const struct device *dev, uint32_t pwm,
 	uint8_t duty_cycle;
 
 	if (period_cycles == 0U) {
-		LOG_ERR("Invalid combination: period_cycles=%d, "
-			    "pulse_cycles=%d", period_cycles, pulse_cycles);
-		return -EINVAL;
+		LOG_ERR("Channel can not be set to inactive level");
+		return -ENOTSUP;
 	}
 
 	if (pwm >= config->channel_count) {

drivers/pwm/pwm_rv32m1_tpm.c

@@ -47,9 +47,8 @@ static int rv32m1_tpm_pin_set(const struct device *dev, uint32_t pwm,
 	uint8_t duty_cycle;
 
 	if (period_cycles == 0U) {
-		LOG_ERR("Invalid combination: period_cycles=%d, "
-			    "pulse_cycles=%d", period_cycles, pulse_cycles);
-		return -EINVAL;
+		LOG_ERR("Channel can not be set to inactive level");
+		return -ENOTSUP;
 	}
 
 	if (pwm >= config->channel_count) {

drivers/pwm/pwm_sam.c

@@ -55,7 +55,7 @@ static int sam_pwm_pin_set(const struct device *dev, uint32_t ch,
 	}
 
 	if (period_cycles == 0U) {
-		return -EINVAL;
+		return -ENOTSUP;
 	}
 
 	if (period_cycles > 0xffff) {