summaryrefslogtreecommitdiff
path: root/arch/arm/mach-at91/mpddrc.c
blob: e2b6a49eb92f1d7996f9c691ca7af22ed403a139 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * Copyright (C) 2013 Atmel Corporation
 *		      Bo Shen <voice.shen@atmel.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <asm/io.h>
#include <asm/arch/atmel_mpddrc.h>

static inline void atmel_mpddr_op(int mode, u32 ram_address)
{
	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;

	writel(mode, &mpddr->mr);
	writel(0, ram_address);
}

static int ddr2_decodtype_is_seq(u32 cr)
{
#if defined(CONFIG_SAMA5D3) || defined(CONFIG_SAMA5D4) || \
	defined(CONFIG_AT91SAM9X5) || defined(CONFIG_AT91SAM9N12)
	if (cr & ATMEL_MPDDRC_CR_DECOD_INTERLEAVED)
		return 0;
#endif
	return 1;
}

int ddr2_init(const unsigned int ram_address,
	      const struct atmel_mpddr *mpddr_value)
{
	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
	u32 ba_off, cr;

	/* Compute bank offset according to NC in configuration register */
	ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
	if (ddr2_decodtype_is_seq(mpddr_value->cr))
		ba_off += ((mpddr_value->cr & ATMEL_MPDDRC_CR_NR_MASK) >> 2) + 11;

	ba_off += (mpddr_value->md & ATMEL_MPDDRC_MD_DBW_MASK) ? 1 : 2;

	/* Program the memory device type into the memory device register */
	writel(mpddr_value->md, &mpddr->md);

	/* Program the configuration register */
	writel(mpddr_value->cr, &mpddr->cr);

	/* Program the timing register */
	writel(mpddr_value->tpr0, &mpddr->tpr0);
	writel(mpddr_value->tpr1, &mpddr->tpr1);
	writel(mpddr_value->tpr2, &mpddr->tpr2);

	/* Issue a NOP command */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);

	/* A 200 us is provided to precede any signal toggle */
	udelay(200);

	/* Issue a NOP command */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);

	/* Issue an all banks precharge command */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);

	/* Issue an extended mode register set(EMRS2) to choose operation */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
		       ram_address + (0x2 << ba_off));

	/* Issue an extended mode register set(EMRS3) to set EMSR to 0 */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
		       ram_address + (0x3 << ba_off));

	/*
	 * Issue an extended mode register set(EMRS1) to enable DLL and
	 * program D.I.C (output driver impedance control)
	 */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
		       ram_address + (0x1 << ba_off));

	/* Enable DLL reset */
	cr = readl(&mpddr->cr);
	writel(cr | ATMEL_MPDDRC_CR_DLL_RESET_ENABLED, &mpddr->cr);

	/* A mode register set(MRS) cycle is issued to reset DLL */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);

	/* Issue an all banks precharge command */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);

	/* Two auto-refresh (CBR) cycles are provided */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);

	/* Disable DLL reset */
	cr = readl(&mpddr->cr);
	writel(cr & (~ATMEL_MPDDRC_CR_DLL_RESET_ENABLED), &mpddr->cr);

	/* A mode register set (MRS) cycle is issued to disable DLL reset */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);

	/* Set OCD calibration in default state */
	cr = readl(&mpddr->cr);
	writel(cr | ATMEL_MPDDRC_CR_OCD_DEFAULT, &mpddr->cr);

	/*
	 * An extended mode register set (EMRS1) cycle is issued
	 * to OCD default value
	 */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
		       ram_address + (0x1 << ba_off));

	 /* OCD calibration mode exit */
	cr = readl(&mpddr->cr);
	writel(cr & (~ATMEL_MPDDRC_CR_OCD_DEFAULT), &mpddr->cr);

	/*
	 * An extended mode register set (EMRS1) cycle is issued
	 * to enable OCD exit
	 */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
		       ram_address + (0x1 << ba_off));

	/* A nornal mode command is provided */
	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);

	/* Perform a write access to any DDR2-SDRAM address */
	writel(0, ram_address);

	/* Write the refresh rate */
	writel(mpddr_value->rtr, &mpddr->rtr);

	return 0;
}