xref: /openbmc/u-boot/arch/arm/mach-zynq/ddrc.c (revision cf0bcd7d)
1 /*
2  * Copyright (C) 2012 - 2013 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2012 - 2017 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 #ifndef CONFIG_ZYNQ_DDRC_INIT
16 void zynq_ddrc_init(void) {}
17 #else
18 /* Control regsiter bitfield definitions */
19 #define ZYNQ_DDRC_CTRLREG_BUSWIDTH_MASK		0xC
20 #define ZYNQ_DDRC_CTRLREG_BUSWIDTH_SHIFT	2
21 #define ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT	1
22 
23 /* ECC scrub regsiter definitions */
24 #define ZYNQ_DDRC_ECC_SCRUBREG_ECC_MODE_MASK	0x7
25 #define ZYNQ_DDRC_ECC_SCRUBREG_ECCMODE_SECDED	0x4
26 
27 void zynq_ddrc_init(void)
28 {
29 	u32 width, ecctype;
30 
31 	width = readl(&ddrc_base->ddrc_ctrl);
32 	width = (width & ZYNQ_DDRC_CTRLREG_BUSWIDTH_MASK) >>
33 					ZYNQ_DDRC_CTRLREG_BUSWIDTH_SHIFT;
34 	ecctype = (readl(&ddrc_base->ecc_scrub) &
35 		ZYNQ_DDRC_ECC_SCRUBREG_ECC_MODE_MASK);
36 
37 	/* ECC is enabled when memory is in 16bit mode and it is enabled */
38 	if ((ecctype == ZYNQ_DDRC_ECC_SCRUBREG_ECCMODE_SECDED) &&
39 	    (width == ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT)) {
40 		puts("ECC enabled ");
41 		/*
42 		 * Clear the first 1MB because it is not initialized from
43 		 * first stage bootloader. To get ECC to work all memory has
44 		 * been initialized by writing any value.
45 		 */
46 		/* cppcheck-suppress nullPointer */
47 		memset((void *)0, 0, 1 * 1024 * 1024);
48 	} else {
49 		puts("ECC disabled ");
50 	}
51 }
52 #endif
53