xref: /openbmc/u-boot/arch/arm/mach-zynq/ddrc.c (revision 6b44ae6b)
1 /*
2  * Copyright (C) 2012 - 2013 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2012 - 2013 Xilinx, Inc. All rights reserved.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <asm/io.h>
10 #include <asm/arch/sys_proto.h>
11 #include <asm/arch/hardware.h>
12 
13 DECLARE_GLOBAL_DATA_PTR;
14 
15 /* Control regsiter bitfield definitions */
16 #define ZYNQ_DDRC_CTRLREG_BUSWIDTH_MASK		0xC
17 #define ZYNQ_DDRC_CTRLREG_BUSWIDTH_SHIFT	2
18 #define ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT	1
19 
20 /* ECC scrub regsiter definitions */
21 #define ZYNQ_DDRC_ECC_SCRUBREG_ECC_MODE_MASK	0x7
22 #define ZYNQ_DDRC_ECC_SCRUBREG_ECCMODE_SECDED	0x4
23 
24 void zynq_ddrc_init(void)
25 {
26 	u32 width, ecctype;
27 
28 	width = readl(&ddrc_base->ddrc_ctrl);
29 	width = (width & ZYNQ_DDRC_CTRLREG_BUSWIDTH_MASK) >>
30 					ZYNQ_DDRC_CTRLREG_BUSWIDTH_SHIFT;
31 	ecctype = (readl(&ddrc_base->ecc_scrub) &
32 		ZYNQ_DDRC_ECC_SCRUBREG_ECC_MODE_MASK);
33 
34 	/* ECC is enabled when memory is in 16bit mode and it is enabled */
35 	if ((ecctype == ZYNQ_DDRC_ECC_SCRUBREG_ECCMODE_SECDED) &&
36 	    (width == ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT)) {
37 		puts("ECC enabled ");
38 		/*
39 		 * Clear the first 1MB because it is not initialized from
40 		 * first stage bootloader. To get ECC to work all memory has
41 		 * been initialized by writing any value.
42 		 */
43 		/* cppcheck-suppress nullPointer */
44 		memset((void *)0, 0, 1 * 1024 * 1024);
45 
46 		gd->ram_size /= 2;
47 	} else {
48 		puts("ECC disabled ");
49 	}
50 }
51