source: branches/reconfiguration/softs/libs/io.h @ 850

Last change on this file since 850 was 850, checked in by cfuguet, 9 years ago

reconf: introducing a softs directory in the reconfiguration branch

  • This softs directory contains a minimalistic (giet-like) library of drivers and some utility functions.
  • Introducing a simple unit test in the vci_cc_vcache_wrapper component to test the newly introduced watchdog timer mechanism. This unit test uses the minimalistic library.
File size: 1.6 KB
Line 
1/**
2 * \file    io.h
3 * \date    5 September 2012
4 * \author  Cesar Fuguet
5 *
6 * Utility functions to write or read memory mapped hardware registers
7 */
8#ifndef IO_H
9#define IO_H
10
11#include <cpu.h>
12
13/**
14 * \brief Read an 32 bits memory mapped hardware register
15 *
16 * \note interrupts should be disabled while executing this function
17 */
18static inline unsigned int ioread32(uint64_t paddr)
19{
20    uint32_t value;
21    uint32_t msb = paddr >> CLUSTER_OFFSET_BITS;
22    uint32_t lsb = paddr & ((1ULL << CLUSTER_OFFSET_BITS)-1);
23
24    asm volatile("mtc2   %2,     $24   \n"  /* DATA_PADDR_EXT <= msb */
25                 "lw     %0,     0(%1) \n"  /* value <= *paddr       */
26                 "mtc2   $0,     $24   \n"  /* DATA_PADDR_EXT <= 0   */
27                 : "=r"(value)
28                 : "r"(lsb), "r"(msb)
29                 : "memory");
30
31    return value;
32}
33
34/**
35 * \brief Write an 32 bits memory mapped hardware register
36 *
37 * \note interrupts should be disabled while executing this function
38 */
39static inline void iowrite32(uint64_t paddr, uint32_t value)
40{
41    uint32_t msb = paddr >> CLUSTER_OFFSET_BITS;
42    uint32_t lsb = paddr & ((1ULL << CLUSTER_OFFSET_BITS)-1);
43
44    asm volatile("mtc2   %2,     $24   \n"  /* DATA_PADDR_EXT <= msb */
45                 "sw     %0,     0(%1) \n"  /* value <= *paddr       */
46                 "mtc2   $0,     $24   \n"  /* DATA_PADDR_EXT <= 0   */
47                 "sync                 \n"
48                 : /* no outputs */
49                 : "r"(value), "r"(lsb), "r"(msb)
50                 : "memory");
51}
52
53#endif
54
55/*
56 * vim: tabstop=4 : softtabstop=4 : shiftwidth=4 : expandtab
57 */
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