linux-zen-server/arch/arm/mach-omap2/sdrc.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#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 "common.h"
#include "clock.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.
*/
static 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);
}
void __init omap2_set_globals_sdrc(void __iomem *sdrc, void __iomem *sms)
{
omap2_sdrc_base = sdrc;
omap2_sms_base = 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();
}