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Mateusz Kulikowski9afdf402016-01-23 11:54:29 +01001/*
2 * Wait for bit with timeout and ctrlc
3 *
4 * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
5 *
6 * SPDX-License-Identifier: GPL-2.0+
7 */
8
9#ifndef __WAIT_BIT_H
10#define __WAIT_BIT_H
11
12#include <common.h>
13#include <console.h>
Michal Simek3cd42182016-12-12 09:46:09 +010014#include <watchdog.h>
Masahiro Yamada1221ce42016-09-21 11:28:55 +090015#include <linux/errno.h>
Mateusz Kulikowski9afdf402016-01-23 11:54:29 +010016#include <asm/io.h>
17
18/**
19 * wait_for_bit() waits for bit set/cleared in register
20 *
21 * Function polls register waiting for specific bit(s) change
22 * (either 0->1 or 1->0). It can fail under two conditions:
23 * - Timeout
24 * - User interaction (CTRL-C)
25 * Function succeeds only if all bits of masked register are set/cleared
26 * (depending on set option).
27 *
28 * @param prefix Prefix added to timeout messagge (message visible only
29 * with debug enabled)
30 * @param reg Register that will be read (using readl())
31 * @param mask Bit(s) of register that must be active
32 * @param set Selects wait condition (bit set or clear)
33 * @param timeout_ms Timeout (in miliseconds)
34 * @param breakable Enables CTRL-C interruption
35 * @return 0 on success, -ETIMEDOUT or -EINTR on failure
36 */
37static inline int wait_for_bit(const char *prefix, const u32 *reg,
38 const u32 mask, const bool set,
39 const unsigned int timeout_ms,
40 const bool breakable)
41{
42 u32 val;
43 unsigned long start = get_timer(0);
44
45 while (1) {
46 val = readl(reg);
47
48 if (!set)
49 val = ~val;
50
51 if ((val & mask) == mask)
52 return 0;
53
54 if (get_timer(start) > timeout_ms)
55 break;
56
57 if (breakable && ctrlc()) {
58 puts("Abort\n");
59 return -EINTR;
60 }
61
62 udelay(1);
Michal Simek3cd42182016-12-12 09:46:09 +010063 WATCHDOG_RESET();
Mateusz Kulikowski9afdf402016-01-23 11:54:29 +010064 }
65
66 debug("%s: Timeout (reg=%p mask=%08x wait_set=%i)\n", prefix, reg, mask,
67 set);
68
69 return -ETIMEDOUT;
70}
71
72
73#endif