blob: 626acfad719001714136704cba55fe99150128cf [file] [log] [blame]
* linux/arch/arm/mach-omap2/prcm.c
* OMAP 24xx Power Reset and Clock Management (PRCM) functions
* Copyright (C) 2005 Nokia Corporation
* Written by Tony Lindgren <>
* Copyright (C) 2007 Texas Instruments, Inc.
* Rajendra Nayak <>
* Some pieces of code Copyright (C) 2005 Texas Instruments, Inc.
* Upgraded with OMAP4 support by Abhijit Pagare <>
* 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.
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/export.h>
#include "common.h"
#include <plat/prcm.h>
#include <plat/irqs.h>
#include "clock.h"
#include "clock2xxx.h"
#include "cm2xxx_3xxx.h"
#include "prm2xxx_3xxx.h"
#include "prm44xx.h"
#include "prminst44xx.h"
#include "prm-regbits-24xx.h"
#include "prm-regbits-44xx.h"
#include "control.h"
void __iomem *prm_base;
void __iomem *cm_base;
void __iomem *cm2_base;
u32 omap_prcm_get_reset_sources(void)
/* XXX This presumably needs modification for 34XX */
if (cpu_is_omap24xx() || cpu_is_omap34xx())
return omap2_prm_read_mod_reg(WKUP_MOD, OMAP2_RM_RSTST) & 0x7f;
if (cpu_is_omap44xx())
return omap2_prm_read_mod_reg(WKUP_MOD, OMAP4_RM_RSTST) & 0x7f;
return 0;
/* Resets clock rates and reboots the system. Only called from system.h */
void omap_prcm_restart(char mode, const char *cmd)
s16 prcm_offs = 0;
if (cpu_is_omap24xx()) {
prcm_offs = WKUP_MOD;
} else if (cpu_is_omap34xx()) {
prcm_offs = OMAP3430_GR_MOD;
omap3_ctrl_write_boot_mode((cmd ? (u8)*cmd : 0));
} else if (cpu_is_omap44xx()) {
omap4_prminst_global_warm_sw_reset(); /* never returns */
} else {
* As per Errata i520, in some cases, user will not be able to
* access DDR memory after warm-reset.
* This situation occurs while the warm-reset happens during a read
* access to DDR memory. In that particular condition, DDR memory
* does not respond to a corrupted read command due to the warm
* reset occurrence but SDRC is waiting for read completion.
* SDRC is not sensitive to the warm reset, but the interconnect is
* reset on the fly, thus causing a misalignment between SDRC logic,
* interconnect logic and DDR memory state.
* Steps to perform before a Warm reset is trigged:
* 1. enable self-refresh on idle request
* 2. put SDRC in idle
* 3. wait until SDRC goes to idle
* 4. generate SW reset (Global SW reset)
* Steps to be performed after warm reset occurs (in bootloader):
* if HW warm reset is the source, apply below steps before any
* accesses to SDRAM:
* 1. Reset SMS and SDRC and wait till reset is complete
* 2. Re-initialize SMS, SDRC and memory
* NOTE: Above work around is required only if arch reset is implemented
* using Global SW reset(GLOBAL_SW_RST). DPLL3 reset does not need
* the WA since it resets SDRC as well as part of cold reset.
/* XXX should be moved to some OMAP2/3 specific code */
omap2_prm_set_mod_reg_bits(OMAP_RST_DPLL3_MASK, prcm_offs,
omap2_prm_read_mod_reg(prcm_offs, OMAP2_RM_RSTCTRL); /* OCP barrier */
* omap2_cm_wait_idlest - wait for IDLEST bit to indicate module readiness
* @reg: physical address of module IDLEST register
* @mask: value to mask against to determine if the module is active
* @idlest: idle state indicator (0 or 1) for the clock
* @name: name of the clock (for printk)
* Returns 1 if the module indicated readiness in time, or 0 if it
* failed to enable in roughly MAX_MODULE_ENABLE_WAIT microseconds.
* XXX This function is deprecated. It should be removed once the
* hwmod conversion is complete.
int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, u8 idlest,
const char *name)
int i = 0;
int ena = 0;
if (idlest)
ena = 0;
ena = mask;
/* Wait for lock */
omap_test_timeout(((__raw_readl(reg) & mask) == ena),
pr_debug("cm: Module associated with clock %s ready after %d "
"loops\n", name, i);
pr_err("cm: Module associated with clock %s didn't enable in "
"%d tries\n", name, MAX_MODULE_ENABLE_WAIT);
return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0;
void __init omap2_set_globals_prcm(struct omap_globals *omap2_globals)
if (omap2_globals->prm)
prm_base = omap2_globals->prm;
if (omap2_globals->cm)
cm_base = omap2_globals->cm;
if (omap2_globals->cm2)
cm2_base = omap2_globals->cm2;