1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SMS/SDRC (SDRAM controller) common code for OMAP2/3
4 *
5 * Copyright (C) 2005, 2008 Texas Instruments Inc.
6 * Copyright (C) 2005, 2008 Nokia Corporation
7 *
8 * Tony Lindgren <tony@atomide.com>
9 * Paul Walmsley
10 * Richard Woodruff <r-woodruff2@ti.com>
11 */
12#undef DEBUG
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/device.h>
17#include <linux/list.h>
18#include <linux/errno.h>
19#include <linux/delay.h>
20#include <linux/clk.h>
21#include <linux/io.h>
22
23#include "common.h"
24#include "clock.h"
25#include "sdrc.h"
26
27static struct omap_sdrc_params *sdrc_init_params_cs0, *sdrc_init_params_cs1;
28
29void __iomem *omap2_sdrc_base;
30void __iomem *omap2_sms_base;
31
32struct omap2_sms_regs {
33 u32 sms_sysconfig;
34};
35
36static struct omap2_sms_regs sms_context;
37
38/* SDRC_POWER register bits */
39#define SDRC_POWER_EXTCLKDIS_SHIFT 3
40#define SDRC_POWER_PWDENA_SHIFT 2
41#define SDRC_POWER_PAGEPOLICY_SHIFT 0
42
43/**
44 * omap2_sms_save_context - Save SMS registers
45 *
46 * Save SMS registers that need to be restored after off mode.
47 */
48static void omap2_sms_save_context(void)
49{
50 sms_context.sms_sysconfig = sms_read_reg(SMS_SYSCONFIG);
51}
52
53/**
54 * omap2_sms_restore_context - Restore SMS registers
55 *
56 * Restore SMS registers that need to be Restored after off mode.
57 */
58void omap2_sms_restore_context(void)
59{
60 sms_write_reg(val: sms_context.sms_sysconfig, SMS_SYSCONFIG);
61}
62
63void __init omap2_set_globals_sdrc(void __iomem *sdrc, void __iomem *sms)
64{
65 omap2_sdrc_base = sdrc;
66 omap2_sms_base = sms;
67}
68
69/**
70 * omap2_sdrc_init - initialize SMS, SDRC devices on boot
71 * @sdrc_cs[01]: pointers to a null-terminated list of struct omap_sdrc_params
72 * Support for 2 chip selects timings
73 *
74 * Turn on smart idle modes for SDRAM scheduler and controller.
75 * Program a known-good configuration for the SDRC to deal with buggy
76 * bootloaders.
77 */
78void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
79 struct omap_sdrc_params *sdrc_cs1)
80{
81 u32 l;
82
83 l = sms_read_reg(SMS_SYSCONFIG);
84 l &= ~(0x3 << 3);
85 l |= (0x2 << 3);
86 sms_write_reg(val: l, SMS_SYSCONFIG);
87
88 l = sdrc_read_reg(SDRC_SYSCONFIG);
89 l &= ~(0x3 << 3);
90 l |= (0x2 << 3);
91 sdrc_write_reg(val: l, SDRC_SYSCONFIG);
92
93 sdrc_init_params_cs0 = sdrc_cs0;
94 sdrc_init_params_cs1 = sdrc_cs1;
95
96 /* XXX Enable SRFRONIDLEREQ here also? */
97 /*
98 * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
99 * can cause random memory corruption
100 */
101 l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
102 (1 << SDRC_POWER_PAGEPOLICY_SHIFT);
103 sdrc_write_reg(val: l, SDRC_POWER);
104 omap2_sms_save_context();
105}
106

source code of linux/arch/arm/mach-omap2/sdrc.c