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/*
* Copyright (c) 2012 The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#ifndef _LINUX_IOPOLL_H
#define _LINUX_IOPOLL_H
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/delay.h>
#include <asm-generic/errno.h>
#include <asm/io.h>
/**
* readl_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
* @addr: Address to poll
* @val: Variable to read the value into
* @cond: Break condition (usually involving @val)
* @sleep_us: Maximum time to sleep between reads in uS (0 tight-loops)
* @timeout_us: Timeout in uS, 0 means never timeout
*
* Returns 0 on success and -ETIMEDOUT upon a timeout. In either
* case, the last read value at @addr is stored in @val. Must not
* be called from atomic context if sleep_us or timeout_us are used.
*/
#define readl_poll_timeout(addr, val, cond, sleep_us, timeout_us) \
({ \
unsigned long timeout = jiffies + usecs_to_jiffies(timeout_us); \
might_sleep_if(timeout_us); \
for (;;) { \
(val) = readl(addr); \
if ((cond) || (timeout_us && time_after(jiffies, timeout))) \
break; \
if (sleep_us) \
usleep_range(DIV_ROUND_UP(sleep_us, 4), sleep_us); \
} \
(cond) ? 0 : -ETIMEDOUT; \
})
/**
* readl_poll_timeout_noirq - Periodically poll an address until a condition is met or a timeout occurs
* @addr: Address to poll
* @val: Variable to read the value into
* @cond: Break condition (usually involving @val)
* @max_reads: Maximum number of reads before giving up
* @time_between_us: Time to udelay() between successive reads
*
* Returns 0 on success and -ETIMEDOUT upon a timeout.
*/
#define readl_poll_timeout_noirq(addr, val, cond, max_reads, time_between_us) \
({ \
int count; \
for (count = (max_reads); count > 0; count--) { \
(val) = readl(addr); \
if (cond) \
break; \
udelay(time_between_us); \
} \
(cond) ? 0 : -ETIMEDOUT; \
})
/**
* readl_poll - Periodically poll an address until a condition is met
* @addr: Address to poll
* @val: Variable to read the value into
* @cond: Break condition (usually involving @val)
* @sleep_us: Maximum time to sleep between reads in uS (0 tight-loops)
*
* Must not be called from atomic context if sleep_us is used.
*/
#define readl_poll(addr, val, cond, sleep_us) \
readl_poll_timeout(addr, val, cond, sleep_us, 0)
/**
* readl_tight_poll_timeout - Tight-loop on an address until a condition is met or a timeout occurs
* @addr: Address to poll
* @val: Variable to read the value into
* @cond: Break condition (usually involving @val)
* @timeout_us: Timeout in uS, 0 means never timeout
*
* Returns 0 on success and -ETIMEDOUT upon a timeout. In either
* case, the last read value at @addr is stored in @val. Must not
* be called from atomic context if timeout_us is used.
*/
#define readl_tight_poll_timeout(addr, val, cond, timeout_us) \
readl_poll_timeout(addr, val, cond, 0, timeout_us)
/**
* readl_tight_poll - Tight-loop on an address until a condition is met
* @addr: Address to poll
* @val: Variable to read the value into
* @cond: Break condition (usually involving @val)
*
* May be called from atomic context.
*/
#define readl_tight_poll(addr, val, cond) \
readl_poll_timeout(addr, val, cond, 0, 0)
#endif /* _LINUX_IOPOLL_H */