mirror of
https://github.com/u-boot/u-boot.git
synced 2024-11-25 05:04:23 +08:00
9afdf4021a
Add function to poll register waiting for specific bit(s). Similar functions are implemented in few drivers - they are almost identical and can be generalized. Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com> Reviewed-by: Tom Rini <trini@konsulko.com>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
|
|
* Wait for bit with timeout and ctrlc
|
|
*
|
|
* (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#ifndef __WAIT_BIT_H
|
|
#define __WAIT_BIT_H
|
|
|
|
#include <common.h>
|
|
#include <console.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/io.h>
|
|
|
|
/**
|
|
* wait_for_bit() waits for bit set/cleared in register
|
|
*
|
|
* Function polls register waiting for specific bit(s) change
|
|
* (either 0->1 or 1->0). It can fail under two conditions:
|
|
* - Timeout
|
|
* - User interaction (CTRL-C)
|
|
* Function succeeds only if all bits of masked register are set/cleared
|
|
* (depending on set option).
|
|
*
|
|
* @param prefix Prefix added to timeout messagge (message visible only
|
|
* with debug enabled)
|
|
* @param reg Register that will be read (using readl())
|
|
* @param mask Bit(s) of register that must be active
|
|
* @param set Selects wait condition (bit set or clear)
|
|
* @param timeout_ms Timeout (in miliseconds)
|
|
* @param breakable Enables CTRL-C interruption
|
|
* @return 0 on success, -ETIMEDOUT or -EINTR on failure
|
|
*/
|
|
static inline int wait_for_bit(const char *prefix, const u32 *reg,
|
|
const u32 mask, const bool set,
|
|
const unsigned int timeout_ms,
|
|
const bool breakable)
|
|
{
|
|
u32 val;
|
|
unsigned long start = get_timer(0);
|
|
|
|
while (1) {
|
|
val = readl(reg);
|
|
|
|
if (!set)
|
|
val = ~val;
|
|
|
|
if ((val & mask) == mask)
|
|
return 0;
|
|
|
|
if (get_timer(start) > timeout_ms)
|
|
break;
|
|
|
|
if (breakable && ctrlc()) {
|
|
puts("Abort\n");
|
|
return -EINTR;
|
|
}
|
|
|
|
udelay(1);
|
|
}
|
|
|
|
debug("%s: Timeout (reg=%p mask=%08x wait_set=%i)\n", prefix, reg, mask,
|
|
set);
|
|
|
|
return -ETIMEDOUT;
|
|
}
|
|
|
|
|
|
#endif
|