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linux/arch/arm/mach-omap2/cm.c

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OMAP2/3/4 PRCM: add module IDLEST wait code After a hardware module's clocks are enabled, Linux must wait for it to indicate readiness via its IDLEST bit before attempting to access the device, otherwise register accesses to the device may trigger an abort. This has traditionally been implemented in the clock framework, but this is the wrong place for it: the clock framework doesn't know which module clocks must be enabled for a module to leave idle; and if a module is not in smart-idle mode, it may never leave idle at all. This type of information is best stored in a per-hardware module data structure (coming in a following patch), rather than a per-clock data structure. The new code will use these new functions to handle waiting for modules to enable. Once hardware module data is filled in for all of the on-chip devices, the clock framework code to handle IDLEST waiting can be removed. Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-09-03 10:14:02 -07:00
/*
* OMAP2/3 CM module functions
*
* Copyright (C) 2009 Nokia Corporation
* Paul Walmsley
*
* 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/module.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/io.h>
#include <asm/atomic.h>
OMAP clock/hwmod: fix off-by-one errors Fix loop bailout off-by-one bugs reported by Juha Leppänen <juha_motorsportcom@luukku.com>. This second version incorporates comments from Russell King <linux@arm.linux.org.uk>. A new macro, 'omap_test_timeout', has been created, with cleaner code, and existing code has been converted to use it. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Juha Leppänen <juha_motorsportcom@luukku.com> Cc: Russell King <linux@arm.linux.org.uk>
2009-12-08 16:33:16 -07:00
#include <plat/common.h>
OMAP2/3/4 PRCM: add module IDLEST wait code After a hardware module's clocks are enabled, Linux must wait for it to indicate readiness via its IDLEST bit before attempting to access the device, otherwise register accesses to the device may trigger an abort. This has traditionally been implemented in the clock framework, but this is the wrong place for it: the clock framework doesn't know which module clocks must be enabled for a module to leave idle; and if a module is not in smart-idle mode, it may never leave idle at all. This type of information is best stored in a per-hardware module data structure (coming in a following patch), rather than a per-clock data structure. The new code will use these new functions to handle waiting for modules to enable. Once hardware module data is filled in for all of the on-chip devices, the clock framework code to handle IDLEST waiting can be removed. Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-09-03 10:14:02 -07:00
#include "cm.h"
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
static const u8 cm_idlest_offs[] = {
CM_IDLEST1, CM_IDLEST2, OMAP2430_CM_IDLEST3
};
/**
* omap2_cm_wait_idlest_ready - wait for a module to leave idle or standby
* @prcm_mod: PRCM module offset
* @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
* @idlest_shift: shift of the bit in the CM_IDLEST* register to check
*
* XXX document
*/
int omap2_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
{
int ena = 0, i = 0;
u8 cm_idlest_reg;
u32 mask;
if (!idlest_id || (idlest_id > ARRAY_SIZE(cm_idlest_offs)))
return -EINVAL;
cm_idlest_reg = cm_idlest_offs[idlest_id - 1];
OMAP24xx: CM: fix mask used for checking IDLEST status On OMAP24xx, the polarity for the IDLEST bits is opposite of OMAP3. The mask used to check this was using the bit position instead of the bit mask. This patch fixes the problem by using the bit mask instead of the bit field. Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-07-26 15:34:28 -07:00
mask = 1 << idlest_shift;
OMAP2/3/4 PRCM: add module IDLEST wait code After a hardware module's clocks are enabled, Linux must wait for it to indicate readiness via its IDLEST bit before attempting to access the device, otherwise register accesses to the device may trigger an abort. This has traditionally been implemented in the clock framework, but this is the wrong place for it: the clock framework doesn't know which module clocks must be enabled for a module to leave idle; and if a module is not in smart-idle mode, it may never leave idle at all. This type of information is best stored in a per-hardware module data structure (coming in a following patch), rather than a per-clock data structure. The new code will use these new functions to handle waiting for modules to enable. Once hardware module data is filled in for all of the on-chip devices, the clock framework code to handle IDLEST waiting can be removed. Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-09-03 10:14:02 -07:00
if (cpu_is_omap24xx())
OMAP24xx: CM: fix mask used for checking IDLEST status On OMAP24xx, the polarity for the IDLEST bits is opposite of OMAP3. The mask used to check this was using the bit position instead of the bit mask. This patch fixes the problem by using the bit mask instead of the bit field. Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-07-26 15:34:28 -07:00
ena = mask;
OMAP2/3/4 PRCM: add module IDLEST wait code After a hardware module's clocks are enabled, Linux must wait for it to indicate readiness via its IDLEST bit before attempting to access the device, otherwise register accesses to the device may trigger an abort. This has traditionally been implemented in the clock framework, but this is the wrong place for it: the clock framework doesn't know which module clocks must be enabled for a module to leave idle; and if a module is not in smart-idle mode, it may never leave idle at all. This type of information is best stored in a per-hardware module data structure (coming in a following patch), rather than a per-clock data structure. The new code will use these new functions to handle waiting for modules to enable. Once hardware module data is filled in for all of the on-chip devices, the clock framework code to handle IDLEST waiting can be removed. Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-09-03 10:14:02 -07:00
else if (cpu_is_omap34xx())
ena = 0;
else
BUG();
/* XXX should be OMAP2 CM */
OMAP clock/hwmod: fix off-by-one errors Fix loop bailout off-by-one bugs reported by Juha Leppänen <juha_motorsportcom@luukku.com>. This second version incorporates comments from Russell King <linux@arm.linux.org.uk>. A new macro, 'omap_test_timeout', has been created, with cleaner code, and existing code has been converted to use it. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Juha Leppänen <juha_motorsportcom@luukku.com> Cc: Russell King <linux@arm.linux.org.uk>
2009-12-08 16:33:16 -07:00
omap_test_timeout(((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) == ena),
MAX_MODULE_READY_TIME, i);
OMAP2/3/4 PRCM: add module IDLEST wait code After a hardware module's clocks are enabled, Linux must wait for it to indicate readiness via its IDLEST bit before attempting to access the device, otherwise register accesses to the device may trigger an abort. This has traditionally been implemented in the clock framework, but this is the wrong place for it: the clock framework doesn't know which module clocks must be enabled for a module to leave idle; and if a module is not in smart-idle mode, it may never leave idle at all. This type of information is best stored in a per-hardware module data structure (coming in a following patch), rather than a per-clock data structure. The new code will use these new functions to handle waiting for modules to enable. Once hardware module data is filled in for all of the on-chip devices, the clock framework code to handle IDLEST waiting can be removed. Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-09-03 10:14:02 -07:00
return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
}
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