text: /*
   * 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
  