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-rw-r--r--arch/arm/mach-omap2/sdrc.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/sdrc.c b/arch/arm/mach-omap2/sdrc.c
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1/*
2 * SMS/SDRC (SDRAM controller) common code for OMAP2/3
3 *
4 * Copyright (C) 2005, 2008 Texas Instruments Inc.
5 * Copyright (C) 2005, 2008 Nokia Corporation
6 *
7 * Tony Lindgren <tony@atomide.com>
8 * Paul Walmsley
9 * Richard Woodruff <r-woodruff2@ti.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15#undef DEBUG
16
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/list.h>
21#include <linux/errno.h>
22#include <linux/delay.h>
23#include <linux/clk.h>
24#include <linux/io.h>
25
26#include <mach/common.h>
27#include <mach/clock.h>
28#include <mach/sram.h>
29
30#include "prm.h"
31
32#include <mach/sdrc.h>
33#include "sdrc.h"
34
35static struct omap_sdrc_params *sdrc_init_params;
36
37void __iomem *omap2_sdrc_base;
38void __iomem *omap2_sms_base;
39
40
41/**
42 * omap2_sdrc_get_params - return SDRC register values for a given clock rate
43 * @r: SDRC clock rate (in Hz)
44 *
45 * Return pre-calculated values for the SDRC_ACTIM_CTRLA,
46 * SDRC_ACTIM_CTRLB, SDRC_RFR_CTRL, and SDRC_MR registers, for a given
47 * SDRC clock rate 'r'. These parameters control various timing
48 * delays in the SDRAM controller that are expressed in terms of the
49 * number of SDRC clock cycles to wait; hence the clock rate
50 * dependency. Note that sdrc_init_params must be sorted rate
51 * descending. Also assumes that both chip-selects use the same
52 * timing parameters. Returns a struct omap_sdrc_params * upon
53 * success, or NULL upon failure.
54 */
55struct omap_sdrc_params *omap2_sdrc_get_params(unsigned long r)
56{
57 struct omap_sdrc_params *sp;
58
59 sp = sdrc_init_params;
60
61 while (sp->rate != r)
62 sp++;
63
64 if (!sp->rate)
65 return NULL;
66
67 return sp;
68}
69
70
71void __init omap2_set_globals_sdrc(struct omap_globals *omap2_globals)
72{
73 omap2_sdrc_base = omap2_globals->sdrc;
74 omap2_sms_base = omap2_globals->sms;
75}
76
77/* turn on smart idle modes for SDRAM scheduler and controller */
78void __init omap2_sdrc_init(struct omap_sdrc_params *sp)
79{
80 u32 l;
81
82 l = sms_read_reg(SMS_SYSCONFIG);
83 l &= ~(0x3 << 3);
84 l |= (0x2 << 3);
85 sms_write_reg(l, SMS_SYSCONFIG);
86
87 l = sdrc_read_reg(SDRC_SYSCONFIG);
88 l &= ~(0x3 << 3);
89 l |= (0x2 << 3);
90 sdrc_write_reg(l, SDRC_SYSCONFIG);
91
92 sdrc_init_params = sp;
93}