LXR uboot/include/wait

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * Wait for bit with timeout and ctrlc
   4 *
   5 * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
   6 */
   7
   8#ifndef __WAIT_BIT_H
   9#define __WAIT_BIT_H
  10
  11#include <console.h>
  12#include <log.h>
  13#include <time.h>
  14#include <watchdog.h>
  15#include <linux/delay.h>
  16#include <linux/errno.h>
  17#include <asm/io.h>
  18
  19/**
  20 * wait_for_bit_x()     waits for bit set/cleared in register
  21 *
  22 * Function polls register waiting for specific bit(s) change
  23 * (either 0->1 or 1->0). It can fail under two conditions:
  24 * - Timeout
  25 * - User interaction (CTRL-C)
  26 * Function succeeds only if all bits of masked register are set/cleared
  27 * (depending on set option).
  28 *
  29 * @param reg           Register that will be read (using read_x())
  30 * @param mask          Bit(s) of register that must be active
  31 * @param set           Selects wait condition (bit set or clear)
  32 * @param timeout_ms    Timeout (in milliseconds)
  33 * @param breakable     Enables CTRL-C interruption
  34 * @return              0 on success, -ETIMEDOUT or -EINTR on failure
  35 */
  36
  37#define BUILD_WAIT_FOR_BIT(sfx, type, read)                             \
  38                                                                        \
  39static inline int wait_for_bit_##sfx(const void *reg,                   \
  40                                     const type mask,                   \
  41                                     const bool set,                    \
  42                                     const unsigned int timeout_ms,     \
  43                                     const bool breakable)              \
  44{                                                                       \
  45        type val;                                                       \
  46        unsigned long start = get_timer(0);                             \
  47                                                                        \
  48        while (1) {                                                     \
  49                val = read(reg);                                        \
  50                                                                        \
  51                if (!set)                                               \
  52                        val = ~val;                                     \
  53                                                                        \
  54                if ((val & mask) == mask)                               \
  55                        return 0;                                       \
  56                                                                        \
  57                if (get_timer(start) > timeout_ms)                      \
  58                        break;                                          \
  59                                                                        \
  60                if (breakable && ctrlc()) {                             \
  61                        puts("Abort\n");                                \
  62                        return -EINTR;                                  \
  63                }                                                       \
  64                                                                        \
  65                udelay(1);                                              \
  66                WATCHDOG_RESET();                                       \
  67        }                                                               \
  68                                                                        \
  69        debug("%s: Timeout (reg=%p mask=%x wait_set=%i)\n", __func__,   \
  70              reg, mask, set);                                          \
  71                                                                        \
  72        return -ETIMEDOUT;                                              \
  73}
  74
  75BUILD_WAIT_FOR_BIT(8, u8, readb)
  76BUILD_WAIT_FOR_BIT(le16, u16, readw)
  77BUILD_WAIT_FOR_BIT(16, u16, readw)
  78#ifdef readw_be
  79BUILD_WAIT_FOR_BIT(be16, u16, readw_be)
  80#endif
  81BUILD_WAIT_FOR_BIT(le32, u32, readl)
  82BUILD_WAIT_FOR_BIT(32, u32, readl)
  83#ifdef readl_be
  84BUILD_WAIT_FOR_BIT(be32, u32, readl_be)
  85#endif
  86
  87#endif
  88