[nrf fromlist] drivers: pwm: nrfx: adjust PWM driver to fast PWM120

Fast PWM120 instance works with 320MHz clock, thus
pwm_nrfx_get_cycles_per_sec needs to be adjusted.
Also, it uses cachable RAM, thus sys_cache function
needs to be added to flush the cached sequence.

Upstream PR #: 80672

Signed-off-by: Michał Stasiak <[email protected]>

Author: mstasiaknordic

drivers/pwm/pwm_nrfx.c

@@ -129,11 +129,6 @@ static int pwm_nrfx_set_cycles(const struct device *dev, uint32_t channel,
 			       uint32_t period_cycles, uint32_t pulse_cycles,
 			       pwm_flags_t flags)
 {
-	/* We assume here that period_cycles will always be 16MHz
-	 * peripheral clock. Since pwm_nrfx_get_cycles_per_sec() function might
-	 * be removed, see ISSUE #6958.
-	 * TODO: Remove this comment when issue has been resolved.
-	 */
 	const struct pwm_nrfx_config *config = dev->config;
 	struct pwm_nrfx_data *data = dev->data;
 	uint16_t compare_value;
@@ -176,6 +171,10 @@ static int pwm_nrfx_set_cycles(const struct device *dev, uint32_t channel,
 
 	seq_values_ptr_get(dev)[channel] = PWM_NRFX_CH_VALUE(compare_value, inverted);
 
+#ifdef CONFIG_NRFX_PWM120
+	sys_cache_data_flush_range((void *)config->seq.values.p_raw, config->seq.length);
+#endif
+
 	LOG_DBG("channel %u, pulse %u, period %u, prescaler: %u.",
 		channel, pulse_cycles, period_cycles, data->prescaler);
 
@@ -243,12 +242,11 @@ static int pwm_nrfx_set_cycles(const struct device *dev, uint32_t channel,
 static int pwm_nrfx_get_cycles_per_sec(const struct device *dev, uint32_t channel,
 				       uint64_t *cycles)
 {
-	/* TODO: Since this function might be removed, we will always return
-	 * 16MHz from this function and handle the conversion with prescaler,
-	 * etc, in the pin set function. See issue #6958.
-	 */
+#ifdef CONFIG_NRFX_PWM120
+	*cycles = 320ul * 1000ul * 1000ul;
+#else
 	*cycles = 16ul * 1000ul * 1000ul;
-
+#endif
 	return 0;
 }