summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/sdrc.c
blob: 9a592199321c5330237faf303500149356604270 (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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
/*
 * SMS/SDRC (SDRAM controller) common code for OMAP2/3
 *
 * Copyright (C) 2005, 2008 Texas Instruments Inc.
 * Copyright (C) 2005, 2008 Nokia Corporation
 *
 * Tony Lindgren <tony@atomide.com>
 * Paul Walmsley
 * Richard Woodruff <r-woodruff2@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <plat/common.h>
#include <plat/clock.h>
#include <plat/sram.h>

#include "prm.h"

#include <plat/sdrc.h>
#include "sdrc.h"

static struct omap_sdrc_params *sdrc_init_params_cs0, *sdrc_init_params_cs1;

void __iomem *omap2_sdrc_base;
void __iomem *omap2_sms_base;

struct omap2_sms_regs {
	u32	sms_sysconfig;
};

static struct omap2_sms_regs sms_context;

/* SDRC_POWER register bits */
#define SDRC_POWER_EXTCLKDIS_SHIFT		3
#define SDRC_POWER_PWDENA_SHIFT			2
#define SDRC_POWER_PAGEPOLICY_SHIFT		0

/**
 * omap2_sms_save_context - Save SMS registers
 *
 * Save SMS registers that need to be restored after off mode.
 */
void omap2_sms_save_context(void)
{
	sms_context.sms_sysconfig = sms_read_reg(SMS_SYSCONFIG);
}

/**
 * omap2_sms_restore_context - Restore SMS registers
 *
 * Restore SMS registers that need to be Restored after off mode.
 */
void omap2_sms_restore_context(void)
{
	sms_write_reg(sms_context.sms_sysconfig, SMS_SYSCONFIG);
}

/**
 * omap2_sdrc_get_params - return SDRC register values for a given clock rate
 * @r: SDRC clock rate (in Hz)
 * @sdrc_cs0: chip select 0 ram timings **
 * @sdrc_cs1: chip select 1 ram timings **
 *
 * Return pre-calculated values for the SDRC_ACTIM_CTRLA,
 *  SDRC_ACTIM_CTRLB, SDRC_RFR_CTRL and SDRC_MR registers in sdrc_cs[01]
 *  structs,for a given SDRC clock rate 'r'.
 * These parameters control various timing delays in the SDRAM controller
 *  that are expressed in terms of the number of SDRC clock cycles to
 *  wait; hence the clock rate dependency.
 *
 * Supports 2 different timing parameters for both chip selects.
 *
 * Note 1: the sdrc_init_params_cs[01] must be sorted rate descending.
 * Note 2: If sdrc_init_params_cs_1 is not NULL it must be of same size
 *  as sdrc_init_params_cs_0.
 *
 * Fills in the struct omap_sdrc_params * for each chip select.
 * Returns 0 upon success or -1 upon failure.
 */
int omap2_sdrc_get_params(unsigned long r,
			  struct omap_sdrc_params **sdrc_cs0,
			  struct omap_sdrc_params **sdrc_cs1)
{
	struct omap_sdrc_params *sp0, *sp1;

	if (!sdrc_init_params_cs0)
		return -1;

	sp0 = sdrc_init_params_cs0;
	sp1 = sdrc_init_params_cs1;

	while (sp0->rate && sp0->rate != r) {
		sp0++;
		if (sdrc_init_params_cs1)
			sp1++;
	}

	if (!sp0->rate)
		return -1;

	*sdrc_cs0 = sp0;
	*sdrc_cs1 = sp1;
	return 0;
}


void __init omap2_set_globals_sdrc(struct omap_globals *omap2_globals)
{
	omap2_sdrc_base = omap2_globals->sdrc;
	omap2_sms_base = omap2_globals->sms;
}

/**
 * omap2_sdrc_init - initialize SMS, SDRC devices on boot
 * @sdrc_cs[01]: pointers to a null-terminated list of struct omap_sdrc_params
 *  Support for 2 chip selects timings
 *
 * Turn on smart idle modes for SDRAM scheduler and controller.
 * Program a known-good configuration for the SDRC to deal with buggy
 * bootloaders.
 */
void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
			    struct omap_sdrc_params *sdrc_cs1)
{
	u32 l;

	l = sms_read_reg(SMS_SYSCONFIG);
	l &= ~(0x3 << 3);
	l |= (0x2 << 3);
	sms_write_reg(l, SMS_SYSCONFIG);

	l = sdrc_read_reg(SDRC_SYSCONFIG);
	l &= ~(0x3 << 3);
	l |= (0x2 << 3);
	sdrc_write_reg(l, SDRC_SYSCONFIG);

	sdrc_init_params_cs0 = sdrc_cs0;
	sdrc_init_params_cs1 = sdrc_cs1;

	/* XXX Enable SRFRONIDLEREQ here also? */
	/*
	 * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
	 * can cause random memory corruption
	 */
	l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
		(1 << SDRC_POWER_PAGEPOLICY_SHIFT);
	sdrc_write_reg(l, SDRC_POWER);
	omap2_sms_save_context();
}
OpenPOWER on IntegriCloud