From 252f63cb487217fe2e18c64b94c26fbb478eef31 Mon Sep 17 00:00:00 2001
From: FrancescoFerraro <francesco.f@variscite.com>
Date: Tue, 19 Oct 2021 08:29:12 +0200
Subject: [PATCH] imx8mm-var-dart: assign PWM3 to M4 using RDC

  This fix the PWM3 behaviour after linux boot
  The PWM is corrupted while linux is booting

Signed-off-by: FrancescoFerraro <francesco.f@variscite.com>
---
 boards/dart_mx8mm/driver_examples/pwm/pwm.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/boards/dart_mx8mm/driver_examples/pwm/pwm.c b/boards/dart_mx8mm/driver_examples/pwm/pwm.c
index f0d87871d..f32bccd4e 100644
--- a/boards/dart_mx8mm/driver_examples/pwm/pwm.c
+++ b/boards/dart_mx8mm/driver_examples/pwm/pwm.c
@@ -13,6 +13,8 @@
 #include "fsl_pwm.h"
 
 #include "fsl_common.h"
+#include "fsl_rdc.h"
+
 /*******************************************************************************
  * Definitions
  ******************************************************************************/
@@ -21,6 +23,7 @@
 #define DEMO_PWM_IRQHandler PWM3_IRQHandler
 /*! @brief PWM period value. PWMO (Hz) = PCLK(Hz) / (period +2) */
 #define PWM_PERIOD_VALUE 30
+#define APP_RDC_PERIPH_PWM3 kRDC_Periph_PWM3
 
 /*******************************************************************************
  * Prototypes
@@ -31,6 +34,8 @@
  ******************************************************************************/
 volatile uint32_t pwmDutycycle = 0U;
 volatile bool pwmDutyUp        = true; /* Indicate PWM Duty cycle is increase or decrease */
+rdc_domain_assignment_t assignment;
+rdc_periph_access_config_t periphConfig;
 
 /*******************************************************************************
  * Code
@@ -66,6 +71,21 @@ void DEMO_PWM_IRQHandler(void)
     SDK_ISR_EXIT_BARRIER;
 }
 
+static void APP_RDC_Periph(void)
+{
+    PRINTF("RDC Peripheral access control\r\n");
+
+    /*
+     * Make PWM3 accessible only by M4
+     */
+    RDC_GetDefaultPeriphAccessConfig(&periphConfig);
+    periphConfig.periph = APP_RDC_PERIPH_PWM3;
+    periphConfig.policy = RDC_ACCESS_POLICY(1, kRDC_ReadWrite);
+    /* Set peripheral to accessible by M4 domain only. */
+    RDC_SetPeriphAccessConfig(RDC, &periphConfig);
+}
+
+
 /*!
  * @brief Main function
  */
@@ -81,6 +101,7 @@ int main(void)
     BOARD_BootClockRUN();
     BOARD_InitDebugConsole();
     BOARD_InitMemory();
+    APP_RDC_Periph();
 
     PRINTF("\r\nPWM driver example.\r\n");