arch/arm64/src/imx9/imx9_tpm_pwm.c: Fix re-starting PWM

When the PWM outputs were stopped, it was not possible to re-start them

Signed-off-by: Jukka Laitinen <[email protected]>

arch/arm64/src/imx9/imx9_tpm_pwm.c

@@ -376,8 +376,29 @@ static void tpm_mux(void)
 
 static int pwm_update_frequency(struct imx9_pwmtimer_s *priv, int freq)
 {
+  int i;
+
   if (freq != priv->frequency)
     {
+      /* Start PWM on all channels if it was previously stopped */
+
+      if (freq > 0 && priv->frequency == 0)
+        {
+          /* Set the EPWM mode for all the configured channels:
+           *
+           * High-true pulses (clear output on counter match, set output
+           * on counter reload, clear output when counter first enabled
+           * or paused)
+           * SC[CPWMS] = 0, MSnB:MSnA = 1:0 ELSnB:ELSnA = 0
+           */
+
+          for (i = 0; i < priv->n_channels; i++)
+            {
+              pwm_putreg(priv, IMX9_TPM_CXSC_OFFSET(CHMUX(priv, i)),
+                         TPM_CXSC_MSB_MASK);
+            }
+        }
+
       priv->period = freq > 0 ? priv->clk / freq : 0;
 
       pwminfo("PWM%d frequency: %" PRIu32" period: %" PRIu32 "\n", priv->id,
@@ -660,20 +681,6 @@ struct pwm_lowerhalf_s *imx9_tpm_pwm_init(tpm_pwm_id_t pwmid)
       pwm_putreg(lower, IMX9_TPM_SC_OFFSET, 1 << TPM_SC_CMOD_SHIFT);
 
       pwminfo("PWM%d at %" PRIxPTR " configured\n", pwmid, lower->base);
-
-      /* Set the EPWM mode for all the configured channels:
-       *
-       * High-true pulses (clear output on counter match, set output
-       * on counter reload, clear output when counter first enabled
-       * or paused)
-       * SC[CPWMS] = 0, MSnB:MSnA = 1:0 ELSnB:ELSnA = 0
-       */
-
-      for (i = 0; i < lower->n_channels; i++)
-        {
-          pwm_putreg(lower, IMX9_TPM_CXSC_OFFSET(CHMUX(lower, i)),
-                     TPM_CXSC_MSB_MASK);
-        }
     }
   else
     {