From 87df4399094a9bc59cb39e77dbb49f263d157bc5 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Sun, 20 May 2018 10:34:27 -0600
Subject: [PATCH] arch/arm/src/imxrt:  Add eDMA initialization logic.

---
 arch/arm/src/imxrt/Kconfig      | 26 ++++++++++++++++++++++++++
 arch/arm/src/imxrt/imxrt_edma.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/arch/arm/src/imxrt/Kconfig b/arch/arm/src/imxrt/Kconfig
index 35fa03aa96f..f87cb577698 100644
--- a/arch/arm/src/imxrt/Kconfig
+++ b/arch/arm/src/imxrt/Kconfig
@@ -73,6 +73,7 @@ menu "LPUART Peripherals"
 config IMXRT_EDMA
 	bool "eDMA"
 	default n
+	select ARCH_DMA
 	depends on EXPERIMENTAL
 
 config IMXRT_LPUART1
@@ -332,4 +333,29 @@ config IMXRT_SRAM_HEAPOFFSET
 
 endmenu  # i.MX6 Primary RAM
 endmenu # Memory Configuration
+
+menu "eDMA Configuration"
+	depends on IMXRT_EDMA
+
+config IMXRT_EDMA_ERCA
+	bool "Round Robin Channel Arbitration"
+	default n
+
+config IMXRT_EDMA_HOE
+	bool "Halt On Error"
+	default y
+
+config IMXRT_EDMA_CLM
+	bool "Continuous Link Mode"
+	default n
+
+config IMXRT_EDMA_EMLIM
+	bool "Minor Loop Mapping"
+	default n
+
+config IMXRT_EDMA_EDBG
+	bool "Enable Debug"
+	default n
+
+endmenu # eDMA Global Configuration
 endif # ARCH_CHIP_IMXRT
diff --git a/arch/arm/src/imxrt/imxrt_edma.c b/arch/arm/src/imxrt/imxrt_edma.c
index 8db84067eb5..be960633cd0 100644
--- a/arch/arm/src/imxrt/imxrt_edma.c
+++ b/arch/arm/src/imxrt/imxrt_edma.c
@@ -355,6 +355,7 @@ static int imxrt_edma_interrupt(int irq, void *context, FAR void *arg)
 
 void weak_function up_dmainitialize(void)
 {
+  uint32_t regval;
   int i;
 
   dmainfo("Initialize eDMA\n");
@@ -363,6 +364,30 @@ void weak_function up_dmainitialize(void)
 
   imxrt_clockrun_dma();
 
+  /* Configure the eDMA controller */
+
+  regval = getreg32(IMXRT_EDMA_CR);
+  regval &= ~(EDMA_CR_EDBG | EDMA_CR_ERCA | EDMA_CR_HOE | EDMA_CR_CLM |
+              EDMA_CR_EMLM);
+
+#ifdef CONFIG_IMXRT_EDMA_EDBG
+  regval |= EDMA_CR_EDBG;   /* Enable Debug */
+#endif
+#ifdef CONFIG_IMXRT_EDMA_ERCA
+  regval |= EDMA_CR_ERCA;   /* Enable Round Robin Channel Arbitration */
+#endif
+#ifdef CONFIG_IMXRT_EDMA_HOE
+  regval |= EDMA_CR_HOE;    /* Halt On Error */
+#endif
+#ifdef CONFIG_IMXRT_EDMA_CLM
+  regval |= EDMA_CR_CLM;    /*  Continuous Link Mode */
+#endif
+#ifdef CONFIG_IMXRT_EDMA_EMLIM
+  regval |= EDMA_CR_EMLM;   /*  Enable Minor Loop Mapping */
+#endif
+
+  putreg32(regval, IMXRT_EDMA_CR);
+
   /* Initialize data structures */
 
   memset(&g_edma, 0, sizeof());
@@ -560,6 +585,9 @@ int imxrt_dmasetup(DMA_HANDLE handle, uint32_t saddr, uint32_t daddr, size_t nby
   /* To initialize the eDMA:
    *
    *   1. Write to the CR if a configuration other than the default is desired.
+   *
+   *      We always use the global default setup by up_dmainitialize()
+   *
    *   2. Write the channel priority levels to the DCHPRIn registers if a
    *      configuration other than the default is desired.
    *   3. Enable error interrupts in the EEI register if so desired.