imxrt:sdram: Add sdram support for imxrt1052-nxp-evk

1. Add sdram item in bsp/imxrt/imxrt1052-nxp-evk/board/Kconfig
2. Add sdram configuration header file for imxrt1052-nxp-evk
3. Update the sdram space assignment for memheap

Signed-off-by: Gavin Liu <gavin-liugang@outlook.com>

bsp/imxrt/imxrt1052-nxp-evk/board/Kconfig

@@ -90,6 +90,10 @@ endmenu
 
 menu "Onboard Peripheral Drivers"
 
+    config BSP_USING_SDRAM
+        bool "Enable SDRAM"
+        default n
+
 endmenu
 
 menu "Board extended module Drivers"

bsp/imxrt/imxrt1052-nxp-evk/board/ports/sdram_port.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-12-05     zylx         The first version for STM32F4xx
+ * 2019-4-25      misonyo      port to IMXRT
+ */
+
+#ifndef SDRAM_PORT_H__
+#define SDRAM_PORT_H__
+
+/* parameters for sdram peripheral */
+
+#define SDRAM_BANK_ADDR                 ((uint32_t)0x80000000U)
+/* region#0/1/2/3: kSEMC_SDRAM_CS0/1/2/3 */
+#define SDRAM_REGION                    kSEMC_SDRAM_CS0
+/* CS pin: kSEMC_MUXCSX0/1/2/3 */
+#define SDRAM_CS_PIN                    kSEMC_MUXCSX0
+/* size(kbyte):32MB = 32*1024*1KBytes */
+#define SDRAM_SIZE                      ((uint32_t)0x8000)
+/* data width: kSEMC_PortSize8Bit,kSEMC_PortSize16Bit */
+#define SDRAM_DATA_WIDTH                kSEMC_PortSize16Bit
+/* column bit numbers: kSEMC_SdramColunm_9/10/11/12bit */
+#define SDRAM_COLUMN_BITS               kSEMC_SdramColunm_9bit
+/* cas latency clock number: kSEMC_LatencyOne/Two/Three */
+#define SDRAM_CAS_LATENCY               kSEMC_LatencyThree
+
+/* Timing configuration for W9825G6KH */
+/* TRP:precharge to active command time (ns) */
+#define SDRAM_TRP                       18
+/* TRCD:active to read/write command delay time (ns) */
+#define SDRAM_TRCD                      18
+/* The time between two refresh commands,Use the maximum of the (Trfc , Txsr).(ns) */
+#define SDRAM_REFRESH_RECOVERY          67
+/* TWR:write recovery time (ns). */
+#define SDRAM_TWR                       12
+/* TRAS:active to precharge command time (ns). */
+#define SDRAM_TRAS       42
+/* TRC time (ns). */
+#define SDRAM_TRC                       60
+/* active to active time (ns). */
+#define SDRAM_ACT2ACT                   60
+/* refresh time (ns). 64ms */
+#define SDRAM_REFRESH_ROW               64 * 1000000 / 8192
+
+#endif /* SDRAM_PORT_H__ */

bsp/imxrt/libraries/drivers/drv_sdram.c

@@ -66,10 +66,17 @@ int rt_hw_sdram_Init(void)
     }
     else
     {
-        LOG_D("sdram init success, mapped at 0x%X, size is %d bytes.", SDRAM_BANK_ADDR, SDRAM_SIZE);
+        LOG_D("sdram init success, mapped at 0x%X, size is %d Kbytes.", SDRAM_BANK_ADDR, SDRAM_SIZE);
 #ifdef RT_USING_MEMHEAP_AS_HEAP
-        /* If RT_USING_MEMHEAP_AS_HEAP is enabled, SDRAM is initialized to the heap */
-        rt_memheap_init(&system_heap, "sdram", (void *)SDRAM_BANK_ADDR, SDRAM_SIZE);
+	/*
+	 * If RT_USING_MEMHEAP_AS_HEAP is enabled, SDRAM is initialized to the heap.
+	 * The heap start address is (base + half size), and the size is (half size - 2M).
+	 * The reasons are:
+	 * 		1. Reserve the half space for SDRAM link case
+	 *		2. Reserve the 2M for non-cache space
+	 */
+        rt_memheap_init(&system_heap, "sdram", (void *)(SDRAM_BANK_ADDR + (SDRAM_SIZE * 1024)/2),
+			(SDRAM_SIZE * 1024)/2 - (2 * 1024 * 1024));
 #endif
     }