linux/arch/arm/mach-omap2/cm.c
Paul Walmsley 6f8b7ff5b0 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>
2009-12-11 17:00:43 -07:00

72 lines
1.6 KiB
C

/*
* 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>
#include <plat/common.h>
#include "cm.h"
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */
#define MAX_MODULE_READY_TIME 20000
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];
if (cpu_is_omap24xx())
ena = idlest_shift;
else if (cpu_is_omap34xx())
ena = 0;
else
BUG();
mask = 1 << idlest_shift;
/* XXX should be OMAP2 CM */
omap_test_timeout(((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) == ena),
MAX_MODULE_READY_TIME, i);
return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
}