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linux/arch/arm/mach-omap2/io.c
Kevin Hilman 414e41286e ARM: OMAP2+: WDTIMER integration: fix !PM boot crash, disarm timer after hwmod reset 
Without runtime PM enabled, hwmod needs to leave all IP blocks in an
enabled state by default so any driver access to the HW will succeed.
This is accomplished by seting the postsetup_state to enabled for all
hwmods during init when runtime PM is disabled.

Currently, we have a special case for WDT in that its postsetup_state
is always set to disabled.  This is done so that the WDT is disabled
and the timer is disarmed at boot in case there is no WDT driver.
This also means that when runtime PM is disabled, if a WDT driver *is*
built in the kernel, the kernel will crash on the first access to the
WDT hardware.

We can't simply leave the WDT module enabled, because the timer is
armed by default after reset. That means that if there is no WDT
driver initialzed or loaded before the timer expires, the kernel will
reboot.

To fix this, a custom reset method is added to the watchdog class of
omap_hwmod.  This method will *always* disarm the timer after hwmod
reset.  The WDT timer then will only be rearmed when/if the driver is
loaded for the WDT.  With the timer disarmed by default, we no longer
need a special-case for the postsetup_state of WDT during init, so it
is removed.

Any platforms wishing to ensure the watchdog remains armed across the
entire boot boot can simply disable the reset-on-init feature of the
watchdog hwmod using omap_hwmod_no_setup_reset().

Tested on 3530/Overo, 4430/Panda.

NOTE: on 4430, the hwmod OCP reset does not seem to rearm the timer as
documented in the TRM (and what happens on OMAP3.)  I noticed this
because testing the HWMOD_INIT_NO_RESET feature with no driver loaded,
I expected a reboot part way through the boot, but did not see a
reboot.  Adding some debug to read the counter, I verified that right
after OCP softreset, the counter is not firing.  After writing the
magic start sequence, the timer starts counting.  This means that the
timer disarm sequence added here does not seem to be needed for 4430,
but is technically the correct way to ensure the timer is disarmed, so
it is left in for OMAP4.

Special thanks to Paul Walmsley for helping brainstorm ideas to fix
this problem.

Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[paul@pwsan.com: updated the omap2_wd_timer_reset() function in the
 wake of commit 3c55c1baff ("ARM:
 OMAP2+: hwmod: Revert "ARM: OMAP2+: hwmod: Make omap_hwmod_softreset
 wait for reset status""); added kerneldoc; rolled in warning fix from Kevin]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2012-05-08 17:25:37 -06:00

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/*
* linux/arch/arm/mach-omap2/io.c
*
* OMAP2 I/O mapping code
*
* Copyright (C) 2005 Nokia Corporation
* Copyright (C) 2007-2009 Texas Instruments
*
* Author:
* Juha Yrjola <juha.yrjola@nokia.com>
* Syed Khasim <x0khasim@ti.com>
*
* Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <asm/tlb.h>
#include <asm/mach/map.h>
#include <plat/sram.h>
#include <plat/sdrc.h>
#include <plat/serial.h>
#include <plat/omap-pm.h>
#include <plat/omap_hwmod.h>
#include <plat/multi.h>
#include "iomap.h"
#include "voltage.h"
#include "powerdomain.h"
#include "clockdomain.h"
#include "common.h"
#include "clock2xxx.h"
#include "clock3xxx.h"
#include "clock44xx.h"
/*
* The machine specific code may provide the extra mapping besides the
* default mapping provided here.
*/
#if defined(CONFIG_SOC_OMAP2420) || defined(CONFIG_SOC_OMAP2430)
static struct map_desc omap24xx_io_desc[] __initdata = {
{
.virtual = L3_24XX_VIRT,
.pfn = __phys_to_pfn(L3_24XX_PHYS),
.length = L3_24XX_SIZE,
.type = MT_DEVICE
},
{
.virtual = L4_24XX_VIRT,
.pfn = __phys_to_pfn(L4_24XX_PHYS),
.length = L4_24XX_SIZE,
.type = MT_DEVICE
},
};
#ifdef CONFIG_SOC_OMAP2420
static struct map_desc omap242x_io_desc[] __initdata = {
{
.virtual = DSP_MEM_2420_VIRT,
.pfn = __phys_to_pfn(DSP_MEM_2420_PHYS),
.length = DSP_MEM_2420_SIZE,
.type = MT_DEVICE
},
{
.virtual = DSP_IPI_2420_VIRT,
.pfn = __phys_to_pfn(DSP_IPI_2420_PHYS),
.length = DSP_IPI_2420_SIZE,
.type = MT_DEVICE
},
{
.virtual = DSP_MMU_2420_VIRT,
.pfn = __phys_to_pfn(DSP_MMU_2420_PHYS),
.length = DSP_MMU_2420_SIZE,
.type = MT_DEVICE
},
};
#endif
#ifdef CONFIG_SOC_OMAP2430
static struct map_desc omap243x_io_desc[] __initdata = {
{
.virtual = L4_WK_243X_VIRT,
.pfn = __phys_to_pfn(L4_WK_243X_PHYS),
.length = L4_WK_243X_SIZE,
.type = MT_DEVICE
},
{
.virtual = OMAP243X_GPMC_VIRT,
.pfn = __phys_to_pfn(OMAP243X_GPMC_PHYS),
.length = OMAP243X_GPMC_SIZE,
.type = MT_DEVICE
},
{
.virtual = OMAP243X_SDRC_VIRT,
.pfn = __phys_to_pfn(OMAP243X_SDRC_PHYS),
.length = OMAP243X_SDRC_SIZE,
.type = MT_DEVICE
},
{
.virtual = OMAP243X_SMS_VIRT,
.pfn = __phys_to_pfn(OMAP243X_SMS_PHYS),
.length = OMAP243X_SMS_SIZE,
.type = MT_DEVICE
},
};
#endif
#endif
#ifdef CONFIG_ARCH_OMAP3
static struct map_desc omap34xx_io_desc[] __initdata = {
{
.virtual = L3_34XX_VIRT,
.pfn = __phys_to_pfn(L3_34XX_PHYS),
.length = L3_34XX_SIZE,
.type = MT_DEVICE
},
{
.virtual = L4_34XX_VIRT,
.pfn = __phys_to_pfn(L4_34XX_PHYS),
.length = L4_34XX_SIZE,
.type = MT_DEVICE
},
{
.virtual = OMAP34XX_GPMC_VIRT,
.pfn = __phys_to_pfn(OMAP34XX_GPMC_PHYS),
.length = OMAP34XX_GPMC_SIZE,
.type = MT_DEVICE
},
{
.virtual = OMAP343X_SMS_VIRT,
.pfn = __phys_to_pfn(OMAP343X_SMS_PHYS),
.length = OMAP343X_SMS_SIZE,
.type = MT_DEVICE
},
{
.virtual = OMAP343X_SDRC_VIRT,
.pfn = __phys_to_pfn(OMAP343X_SDRC_PHYS),
.length = OMAP343X_SDRC_SIZE,
.type = MT_DEVICE
},
{
.virtual = L4_PER_34XX_VIRT,
.pfn = __phys_to_pfn(L4_PER_34XX_PHYS),
.length = L4_PER_34XX_SIZE,
.type = MT_DEVICE
},
{
.virtual = L4_EMU_34XX_VIRT,
.pfn = __phys_to_pfn(L4_EMU_34XX_PHYS),
.length = L4_EMU_34XX_SIZE,
.type = MT_DEVICE
},
#if defined(CONFIG_DEBUG_LL) && \
(defined(CONFIG_MACH_OMAP_ZOOM2) || defined(CONFIG_MACH_OMAP_ZOOM3))
{
.virtual = ZOOM_UART_VIRT,
.pfn = __phys_to_pfn(ZOOM_UART_BASE),
.length = SZ_1M,
.type = MT_DEVICE
},
#endif
};
#endif
#ifdef CONFIG_SOC_OMAPTI81XX
static struct map_desc omapti81xx_io_desc[] __initdata = {
{
.virtual = L4_34XX_VIRT,
.pfn = __phys_to_pfn(L4_34XX_PHYS),
.length = L4_34XX_SIZE,
.type = MT_DEVICE
}
};
#endif
#ifdef CONFIG_SOC_OMAPAM33XX
static struct map_desc omapam33xx_io_desc[] __initdata = {
{
.virtual = L4_34XX_VIRT,
.pfn = __phys_to_pfn(L4_34XX_PHYS),
.length = L4_34XX_SIZE,
.type = MT_DEVICE
},
{
.virtual = L4_WK_AM33XX_VIRT,
.pfn = __phys_to_pfn(L4_WK_AM33XX_PHYS),
.length = L4_WK_AM33XX_SIZE,
.type = MT_DEVICE
}
};
#endif
#ifdef CONFIG_ARCH_OMAP4
static struct map_desc omap44xx_io_desc[] __initdata = {
{
.virtual = L3_44XX_VIRT,
.pfn = __phys_to_pfn(L3_44XX_PHYS),
.length = L3_44XX_SIZE,
.type = MT_DEVICE,
},
{
.virtual = L4_44XX_VIRT,
.pfn = __phys_to_pfn(L4_44XX_PHYS),
.length = L4_44XX_SIZE,
.type = MT_DEVICE,
},
{
.virtual = OMAP44XX_GPMC_VIRT,
.pfn = __phys_to_pfn(OMAP44XX_GPMC_PHYS),
.length = OMAP44XX_GPMC_SIZE,
.type = MT_DEVICE,
},
{
.virtual = OMAP44XX_EMIF1_VIRT,
.pfn = __phys_to_pfn(OMAP44XX_EMIF1_PHYS),
.length = OMAP44XX_EMIF1_SIZE,
.type = MT_DEVICE,
},
{
.virtual = OMAP44XX_EMIF2_VIRT,
.pfn = __phys_to_pfn(OMAP44XX_EMIF2_PHYS),
.length = OMAP44XX_EMIF2_SIZE,
.type = MT_DEVICE,
},
{
.virtual = OMAP44XX_DMM_VIRT,
.pfn = __phys_to_pfn(OMAP44XX_DMM_PHYS),
.length = OMAP44XX_DMM_SIZE,
.type = MT_DEVICE,
},
{
.virtual = L4_PER_44XX_VIRT,
.pfn = __phys_to_pfn(L4_PER_44XX_PHYS),
.length = L4_PER_44XX_SIZE,
.type = MT_DEVICE,
},
{
.virtual = L4_EMU_44XX_VIRT,
.pfn = __phys_to_pfn(L4_EMU_44XX_PHYS),
.length = L4_EMU_44XX_SIZE,
.type = MT_DEVICE,
},
#ifdef CONFIG_OMAP4_ERRATA_I688
{
.virtual = OMAP4_SRAM_VA,
.pfn = __phys_to_pfn(OMAP4_SRAM_PA),
.length = PAGE_SIZE,
.type = MT_MEMORY_SO,
},
#endif
};
#endif
#ifdef CONFIG_SOC_OMAP2420
void __init omap242x_map_common_io(void)
{
iotable_init(omap24xx_io_desc, ARRAY_SIZE(omap24xx_io_desc));
iotable_init(omap242x_io_desc, ARRAY_SIZE(omap242x_io_desc));
}
#endif
#ifdef CONFIG_SOC_OMAP2430
void __init omap243x_map_common_io(void)
{
iotable_init(omap24xx_io_desc, ARRAY_SIZE(omap24xx_io_desc));
iotable_init(omap243x_io_desc, ARRAY_SIZE(omap243x_io_desc));
}
#endif
#ifdef CONFIG_ARCH_OMAP3
void __init omap34xx_map_common_io(void)
{
iotable_init(omap34xx_io_desc, ARRAY_SIZE(omap34xx_io_desc));
}
#endif
#ifdef CONFIG_SOC_OMAPTI81XX
void __init omapti81xx_map_common_io(void)
{
iotable_init(omapti81xx_io_desc, ARRAY_SIZE(omapti81xx_io_desc));
}
#endif
#ifdef CONFIG_SOC_OMAPAM33XX
void __init omapam33xx_map_common_io(void)
{
iotable_init(omapam33xx_io_desc, ARRAY_SIZE(omapam33xx_io_desc));
}
#endif
#ifdef CONFIG_ARCH_OMAP4
void __init omap44xx_map_common_io(void)
{
iotable_init(omap44xx_io_desc, ARRAY_SIZE(omap44xx_io_desc));
omap_barriers_init();
}
#endif
/*
* omap2_init_reprogram_sdrc - reprogram SDRC timing parameters
*
* Sets the CORE DPLL3 M2 divider to the same value that it's at
* currently. This has the effect of setting the SDRC SDRAM AC timing
* registers to the values currently defined by the kernel. Currently
* only defined for OMAP3; will return 0 if called on OMAP2. Returns
* -EINVAL if the dpll3_m2_ck cannot be found, 0 if called on OMAP2,
* or passes along the return value of clk_set_rate().
*/
static int __init _omap2_init_reprogram_sdrc(void)
{
struct clk *dpll3_m2_ck;
int v = -EINVAL;
long rate;
if (!cpu_is_omap34xx())
return 0;
dpll3_m2_ck = clk_get(NULL, "dpll3_m2_ck");
if (IS_ERR(dpll3_m2_ck))
return -EINVAL;
rate = clk_get_rate(dpll3_m2_ck);
pr_info("Reprogramming SDRC clock to %ld Hz\n", rate);
v = clk_set_rate(dpll3_m2_ck, rate);
if (v)
pr_err("dpll3_m2_clk rate change failed: %d\n", v);
clk_put(dpll3_m2_ck);
return v;
}
static int _set_hwmod_postsetup_state(struct omap_hwmod *oh, void *data)
{
return omap_hwmod_set_postsetup_state(oh, *(u8 *)data);
}
static void __init omap_common_init_early(void)
{
omap_init_consistent_dma_size();
}
static void __init omap_hwmod_init_postsetup(void)
{
u8 postsetup_state;
/* Set the default postsetup state for all hwmods */
#ifdef CONFIG_PM_RUNTIME
postsetup_state = _HWMOD_STATE_IDLE;
#else
postsetup_state = _HWMOD_STATE_ENABLED;
#endif
omap_hwmod_for_each(_set_hwmod_postsetup_state, &postsetup_state);
omap_pm_if_early_init();
}
#ifdef CONFIG_SOC_OMAP2420
void __init omap2420_init_early(void)
{
omap2_set_globals_242x();
omap2xxx_check_revision();
omap_common_init_early();
omap2xxx_voltagedomains_init();
omap242x_powerdomains_init();
omap242x_clockdomains_init();
omap2420_hwmod_init();
omap_hwmod_init_postsetup();
omap2420_clk_init();
}
#endif
#ifdef CONFIG_SOC_OMAP2430
void __init omap2430_init_early(void)
{
omap2_set_globals_243x();
omap2xxx_check_revision();
omap_common_init_early();
omap2xxx_voltagedomains_init();
omap243x_powerdomains_init();
omap243x_clockdomains_init();
omap2430_hwmod_init();
omap_hwmod_init_postsetup();
omap2430_clk_init();
}
#endif
/*
* Currently only board-omap3beagle.c should call this because of the
* same machine_id for 34xx and 36xx beagle.. Will get fixed with DT.
*/
#ifdef CONFIG_ARCH_OMAP3
void __init omap3_init_early(void)
{
omap2_set_globals_3xxx();
omap3xxx_check_revision();
omap3xxx_check_features();
omap_common_init_early();
omap3xxx_voltagedomains_init();
omap3xxx_powerdomains_init();
omap3xxx_clockdomains_init();
omap3xxx_hwmod_init();
omap_hwmod_init_postsetup();
omap3xxx_clk_init();
}
void __init omap3430_init_early(void)
{
omap3_init_early();
}
void __init omap35xx_init_early(void)
{
omap3_init_early();
}
void __init omap3630_init_early(void)
{
omap3_init_early();
}
void __init am35xx_init_early(void)
{
omap3_init_early();
}
void __init ti81xx_init_early(void)
{
omap2_set_globals_ti81xx();
omap3xxx_check_revision();
ti81xx_check_features();
omap_common_init_early();
omap3xxx_voltagedomains_init();
omap3xxx_powerdomains_init();
omap3xxx_clockdomains_init();
omap3xxx_hwmod_init();
omap_hwmod_init_postsetup();
omap3xxx_clk_init();
}
#endif
#ifdef CONFIG_ARCH_OMAP4
void __init omap4430_init_early(void)
{
omap2_set_globals_443x();
omap4xxx_check_revision();
omap4xxx_check_features();
omap_common_init_early();
omap44xx_voltagedomains_init();
omap44xx_powerdomains_init();
omap44xx_clockdomains_init();
omap44xx_hwmod_init();
omap_hwmod_init_postsetup();
omap4xxx_clk_init();
}
#endif
void __init omap_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
struct omap_sdrc_params *sdrc_cs1)
{
omap_sram_init();
if (cpu_is_omap24xx() || omap3_has_sdrc()) {
omap2_sdrc_init(sdrc_cs0, sdrc_cs1);
_omap2_init_reprogram_sdrc();
}
}
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