rt-thread/bsp/loongson/ls1bdev/libraries/ls1b_public.c

194 lines
3.0 KiB
C

/*
* Copyright (c) 2006-2018, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2017-09-06 勤为本 first version
* 2021-02-02 michael5hzg@gmail.com adapt to ls1b
*/
// 一些常用的、共用的接口
/*
* 将指定寄存器的指定位置1
* @reg 寄存器地址
* @bit 需要置1的那一bit
*/
void reg_set_one_bit(volatile unsigned int *reg, unsigned int bit)
{
unsigned int temp, mask;
mask = 1 << bit;
temp = *reg;
temp |= mask;
*reg = temp;
return ;
}
/*
* 将指定寄存器的指定位清零
* @reg 寄存器地址
* @bit 需要清零的那一bit
*/
void reg_clr_one_bit(volatile unsigned int *reg, unsigned int bit)
{
unsigned int temp, mask;
mask = 1 << bit;
temp = *reg;
temp &= ~mask;
*reg = temp;
return ;
}
/*
* 获取指定寄存器的指定位的值
* @reg 寄存器地址
* @bit 需要读取值的那一bit
* @ret 指定位的值
*/
unsigned int reg_get_bit(volatile unsigned int *reg, unsigned int bit)
{
unsigned int temp;
temp = *reg;
temp = (temp >> bit) & 1;
return temp;
}
/*
* 向寄存器中写入8bit(一个字节)数据
* @data 待写入的数据
* @addr 寄存器地址
*/
void reg_write_8(unsigned char data, volatile unsigned char *addr)
{
*addr = data;
}
/*
* 从寄存器读出8bit(一个字节)数据
* @addr 寄存器地址
* @ret 读出的数据
*/
unsigned char reg_read_8(volatile unsigned char *addr)
{
return (*addr);
}
/*
* 向寄存器中写一个32bit的数据
* @data 待写入的数据
* @addr 寄存器地址
*/
void reg_write_32(unsigned int data, volatile unsigned int *addr)
{
*addr = data;
}
/*
* 从寄存器读出一个32bit数据
* @addr 寄存器地址
* @ret 读出的数据
*/
unsigned int reg_read_32(volatile unsigned int *addr)
{
return (*addr);
}
/**
* ffs - find first bit set
* @x: the word to search
*
* This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
int ls1b_ffs(int x)
{
int r = 1;
if (!x)
return 0;
if (!(x & 0xffff)) {
x >>= 16;
r += 16;
}
if (!(x & 0xff)) {
x >>= 8;
r += 8;
}
if (!(x & 0xf)) {
x >>= 4;
r += 4;
}
if (!(x & 3)) {
x >>= 2;
r += 2;
}
if (!(x & 1)) {
x >>= 1;
r += 1;
}
return r;
}
/*
* fls - find last (most-significant) bit set
* @x: the word to search
*
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
int ls1b_fls(int x)
{
int r = 32;
if (!x)
return 0;
if (!(x & 0xffff0000u))
{
x <<= 16;
r -= 16;
}
if (!(x & 0xff000000u))
{
x <<= 8;
r -= 8;
}
if (!(x & 0xf0000000u))
{
x <<= 4;
r -= 4;
}
if (!(x & 0xc0000000u))
{
x <<= 2;
r -= 2;
}
if (!(x & 0x80000000u))
{
x <<= 1;
r -= 1;
}
return r;
}