OpenCloudOS-Kernel/arch/arm/mach-omap2/cm4xxx.c

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/*
* OMAP4 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 "cm.h"
#include "cm-regbits-4xxx.h"
/* XXX move this to cm.h */
/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */
#define MAX_MODULE_READY_TIME 20000
/*
* OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK: isolates the IDLEST field in the
* CM_CLKCTRL register.
*/
#define OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK (0x2 << 16)
/*
* OMAP4 prcm_mod u32 fields contain packed data: the CM ID in bit 16 and
* the PRCM module offset address (from the CM module base) in bits 15-0.
*/
#define OMAP4_PRCM_MOD_CM_ID_SHIFT 16
#define OMAP4_PRCM_MOD_OFFS_MASK 0xffff
/**
* omap4_cm_wait_idlest_ready - wait for a module to leave idle or standby
* @prcm_mod: PRCM module offset (XXX example)
* @prcm_dev_offs: PRCM device offset (e.g. MCASP XXX example)
*
* XXX document
*/
int omap4_cm_wait_idlest_ready(u32 prcm_mod, u8 prcm_dev_offs)
{
int i = 0;
u8 cm_id;
u16 prcm_mod_offs;
u32 mask = OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK;
cm_id = prcm_mod >> OMAP4_PRCM_MOD_CM_ID_SHIFT;
prcm_mod_offs = prcm_mod & OMAP4_PRCM_MOD_OFFS_MASK;
while (((omap4_cm_read_mod_reg(cm_id, prcm_mod_offs, prcm_dev_offs,
OMAP4_CM_CLKCTRL_DREG) & mask) != 0) &&
(i++ < MAX_MODULE_READY_TIME))
udelay(1);
return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
}