168 lines
4.9 KiB
C
168 lines
4.9 KiB
C
/*
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* linux/arch/arm/mach-omap2/prcm.c
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*
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* OMAP 24xx Power Reset and Clock Management (PRCM) functions
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*
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* Copyright (C) 2005 Nokia Corporation
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*
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* Written by Tony Lindgren <tony.lindgren@nokia.com>
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*
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* Copyright (C) 2007 Texas Instruments, Inc.
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* Rajendra Nayak <rnayak@ti.com>
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*
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* Some pieces of code Copyright (C) 2005 Texas Instruments, Inc.
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* Upgraded with OMAP4 support by Abhijit Pagare <abhijitpagare@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/delay.h>
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#include <mach/system.h>
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#include <plat/common.h>
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#include <plat/prcm.h>
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#include <plat/irqs.h>
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#include "clock.h"
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#include "clock2xxx.h"
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#include "cm2xxx_3xxx.h"
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#include "prm2xxx_3xxx.h"
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#include "prm44xx.h"
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#include "prminst44xx.h"
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#include "prm-regbits-24xx.h"
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#include "prm-regbits-44xx.h"
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#include "control.h"
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void __iomem *prm_base;
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void __iomem *cm_base;
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void __iomem *cm2_base;
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#define MAX_MODULE_ENABLE_WAIT 100000
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u32 omap_prcm_get_reset_sources(void)
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{
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/* XXX This presumably needs modification for 34XX */
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if (cpu_is_omap24xx() || cpu_is_omap34xx())
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return omap2_prm_read_mod_reg(WKUP_MOD, OMAP2_RM_RSTST) & 0x7f;
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if (cpu_is_omap44xx())
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return omap2_prm_read_mod_reg(WKUP_MOD, OMAP4_RM_RSTST) & 0x7f;
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return 0;
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}
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EXPORT_SYMBOL(omap_prcm_get_reset_sources);
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/* Resets clock rates and reboots the system. Only called from system.h */
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static void omap_prcm_arch_reset(char mode, const char *cmd)
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{
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s16 prcm_offs = 0;
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if (cpu_is_omap24xx()) {
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omap2xxx_clk_prepare_for_reboot();
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prcm_offs = WKUP_MOD;
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} else if (cpu_is_omap34xx()) {
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prcm_offs = OMAP3430_GR_MOD;
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omap3_ctrl_write_boot_mode((cmd ? (u8)*cmd : 0));
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} else if (cpu_is_omap44xx()) {
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omap4_prminst_global_warm_sw_reset(); /* never returns */
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} else {
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WARN_ON(1);
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}
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/*
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* As per Errata i520, in some cases, user will not be able to
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* access DDR memory after warm-reset.
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* This situation occurs while the warm-reset happens during a read
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* access to DDR memory. In that particular condition, DDR memory
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* does not respond to a corrupted read command due to the warm
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* reset occurrence but SDRC is waiting for read completion.
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* SDRC is not sensitive to the warm reset, but the interconnect is
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* reset on the fly, thus causing a misalignment between SDRC logic,
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* interconnect logic and DDR memory state.
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* WORKAROUND:
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* Steps to perform before a Warm reset is trigged:
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* 1. enable self-refresh on idle request
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* 2. put SDRC in idle
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* 3. wait until SDRC goes to idle
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* 4. generate SW reset (Global SW reset)
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*
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* Steps to be performed after warm reset occurs (in bootloader):
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* if HW warm reset is the source, apply below steps before any
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* accesses to SDRAM:
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* 1. Reset SMS and SDRC and wait till reset is complete
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* 2. Re-initialize SMS, SDRC and memory
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*
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* NOTE: Above work around is required only if arch reset is implemented
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* using Global SW reset(GLOBAL_SW_RST). DPLL3 reset does not need
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* the WA since it resets SDRC as well as part of cold reset.
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*/
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/* XXX should be moved to some OMAP2/3 specific code */
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omap2_prm_set_mod_reg_bits(OMAP_RST_DPLL3_MASK, prcm_offs,
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OMAP2_RM_RSTCTRL);
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omap2_prm_read_mod_reg(prcm_offs, OMAP2_RM_RSTCTRL); /* OCP barrier */
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}
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void (*arch_reset)(char, const char *) = omap_prcm_arch_reset;
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/**
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* omap2_cm_wait_idlest - wait for IDLEST bit to indicate module readiness
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* @reg: physical address of module IDLEST register
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* @mask: value to mask against to determine if the module is active
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* @idlest: idle state indicator (0 or 1) for the clock
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* @name: name of the clock (for printk)
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*
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* Returns 1 if the module indicated readiness in time, or 0 if it
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* failed to enable in roughly MAX_MODULE_ENABLE_WAIT microseconds.
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*
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* XXX This function is deprecated. It should be removed once the
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* hwmod conversion is complete.
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*/
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int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, u8 idlest,
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const char *name)
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{
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int i = 0;
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int ena = 0;
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if (idlest)
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ena = 0;
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else
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ena = mask;
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/* Wait for lock */
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omap_test_timeout(((__raw_readl(reg) & mask) == ena),
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MAX_MODULE_ENABLE_WAIT, i);
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if (i < MAX_MODULE_ENABLE_WAIT)
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pr_debug("cm: Module associated with clock %s ready after %d "
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"loops\n", name, i);
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else
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pr_err("cm: Module associated with clock %s didn't enable in "
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"%d tries\n", name, MAX_MODULE_ENABLE_WAIT);
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return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0;
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};
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void __init omap2_set_globals_prcm(struct omap_globals *omap2_globals)
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{
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/* Static mapping, never released */
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if (omap2_globals->prm) {
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prm_base = ioremap(omap2_globals->prm, SZ_8K);
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WARN_ON(!prm_base);
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}
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if (omap2_globals->cm) {
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cm_base = ioremap(omap2_globals->cm, SZ_8K);
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WARN_ON(!cm_base);
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}
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if (omap2_globals->cm2) {
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cm2_base = ioremap(omap2_globals->cm2, SZ_8K);
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WARN_ON(!cm2_base);
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}
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}
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