rt-thread/bsp/loongson/ls1cdev/libraries/ls1c_spi.c

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/*
* Copyright (c) 2006-2018, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2017-10-23 勤为本 first version
*/
// 硬件spi接口源文件
#include <string.h>
#include "ls1c_public.h"
#include "ls1c_regs.h"
#include "ls1c_clock.h"
#include "ls1c_spi.h"
/*
* 获取指定SPI模块的基地址
* @SPIx SPI模块的编号
*/
void *ls1c_spi_get_base(unsigned char SPIx)
{
void *base = NULL;
switch (SPIx)
{
case LS1C_SPI_0:
base = (void *)LS1C_SPI0_BASE;
break;
case LS1C_SPI_1:
base = (void *)LS1C_SPI1_BASE;
break;
default:
base = NULL;
break;
}
return base;
}
/*
* 打印指定SPI模块的所有寄存器的值
* @spi_base 基地址
*/
void ls1c_spi_print_all_regs_info(void *spi_base)
{
printf("[%s] SPCR=0x%x, SPSR=0x%x, SPER=0x%x, SFC_PARAM=0x%x, SFC_SOFTCS=0x%x, SFC_TIMING=0x%x\r\n",
__FUNCTION__,
reg_read_8(spi_base + LS1C_SPI_SPCR_OFFSET),
reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET),
reg_read_8(spi_base + LS1C_SPI_SPER_OFFSET),
reg_read_8(spi_base + LS1C_SPI_SFC_PARAM_OFFSET),
reg_read_8(spi_base + LS1C_SPI_SFC_SOFTCS_OFFSET),
reg_read_8(spi_base + LS1C_SPI_SFC_TIMING_OFFSET));
return ;
}
/*
* 根据SPI时钟频率计算分频系数
* @max_speed_hz SPI最大通信速度
* @ret 分频系数
*/
unsigned int ls1c_spi_get_div(unsigned int max_speed_hz)
{
unsigned long clk = 0;
unsigned int div = 0;
unsigned int div_tmp = 0;
unsigned int bit = 0;
clk = clk_get_apb_rate();
div = DIV_ROUND_UP(clk, max_speed_hz);
if (div < 2)
div = 2;
if (div > 4096)
div = 4096;
bit = ls1c_fls(div) - 1;
switch (1 << bit)
{
case 16:
div_tmp = 2;
if (div > (1 << bit))
{
div_tmp++;
}
break;
case 32:
div_tmp = 3;
if (div > (1 << bit))
{
div_tmp += 2;
}
break;
case 8:
div_tmp = 4;
if (div > (1 << bit))
{
div_tmp -= 2;
}
break;
default:
div_tmp = bit - 1;
if (div > (1 << bit))
{
div_tmp++;
}
break;
}
/*
printf("[%s] clk=%ld, max_speed_hz=%d, div_tmp=%d, bit=%d\r\n",
__FUNCTION__, clk, max_speed_hz, div_tmp, bit);
*/
return div_tmp;
}
/*
* 设置时钟
* @spi_base 基地址
* @max_hz 最大频率单位hz
*/
void ls1c_spi_set_clock(void *spi_base, unsigned long max_hz)
{
unsigned int div = 0;
unsigned char val = 0;
// 获取分频系数
div = ls1c_spi_get_div(max_hz);
// 设置spr
val = reg_read_8(spi_base + LS1C_SPI_SPCR_OFFSET);
val &= (~LS1C_SPI_SPCR_SPR_MASK); // spr清零
val |= (div & LS1C_SPI_SPCR_SPR_MASK); // 设置新的spr
reg_write_8(val, spi_base + LS1C_SPI_SPCR_OFFSET);
// 设置spre
val = reg_read_8(spi_base + LS1C_SPI_SPER_OFFSET);
val &= (~LS1C_SPI_SPER_SPRE_MASK); // spre清零
val |= ((div >> 2) & LS1C_SPI_SPER_SPRE_MASK); // 设置新的spre
reg_write_8(val, spi_base + LS1C_SPI_SPER_OFFSET);
return ;
}
/*
* 设置通信模式(时钟极性和相位)
* @spi_base 基地址
* @cpol 时钟极性
* @cpha 时钟相位
*/
void ls1c_spi_set_mode(void *spi_base, unsigned char cpol, unsigned char cpha)
{
unsigned char val = 0;
val = reg_read_8(spi_base + LS1C_SPI_SPCR_OFFSET);
// 设置时钟极性--cpol
val &= (~LS1C_SPI_SPCR_CPOL_MASK); // cpol清0
val |= (cpol << LS1C_SPI_SPCR_CPOL_BIT); // 写入新的cpol
// 设置时钟相位--cpha
val &= (~LS1C_SPI_SPCR_CPHA_MASK); // cpha清0
val |= (cpha << LS1C_SPI_SPCR_CPHA_BIT); // 写入新的cpha
reg_write_8(val, spi_base + LS1C_SPI_SPCR_OFFSET);
return ;
}
/*
* 设置指定片选为指定状态
* @spi_base 基地址
* @cs 片选
* @new_status 片选引脚的新状态取值为0或1即高电平或低电平
*/
void ls1c_spi_set_cs(void *spi_base, unsigned char cs, int new_status)
{
unsigned char val = 0;
val = reg_read_8(spi_base + LS1C_SPI_SFC_SOFTCS_OFFSET);
val |= 0x01 << cs ; //对应的csen=1
if (new_status) // cs = 1
{
val |= (0x10 << cs); // 指定csn=1
}
else // cs = 0
{
val &= ~(0x10 << cs); // 指定csn=0
}
reg_write_8(val, spi_base + LS1C_SPI_SFC_SOFTCS_OFFSET);
return ;
}
/*
* 等待收发完成
* @spi_base 基地址
*/
void ls1c_spi_wait_txrx_done(void *spi_base)
{
int timeout = LS1C_SPI_TX_TIMEOUT;
while (timeout--)
{
if (LS1C_SPI_SPSR_SPIF_MASK & reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET))
break;
}
return ;
}
/*
* 清中断和标志位
* @spi_base 基地址
*/
void ls1c_spi_clear(void *spi_base)
{
unsigned char val = 0;
// 清中断
val = reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET);
val |= LS1C_SPI_SPSR_SPIF_MASK;
reg_write_8(val, spi_base + LS1C_SPI_SPSR_OFFSET);
// 清溢出标志位(Write-Collision Clear)
val = reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET);
if (LS1C_SPI_SPSR_WCOL_MASK & val)
{
printf("[%s] clear register SPSR's wcol!\r\n", __FUNCTION__); // 手册和linux源码中不一样加个打印看看
reg_write_8(val & ~LS1C_SPI_SPSR_WCOL_MASK, spi_base + LS1C_SPI_SPSR_OFFSET); // 写0linux源码中是写0
// reg_write_8(val | LS1C_SPI_SPSR_WCOL_MASK, spi_base + LS1C_SPI_SPSR_OFFSET); // 写1按照1c手册应该写1
}
return ;
}
/*
* 通过指定SPI发送接收一个字节
* 注意,在多任务的系统中,此函数需要互斥。
* 即保证在和某个从设备收发某个字节的过程中不能被切换到其它任务同时与另外的在同一个SPI总线上的从设备通信
* 因为龙芯1c的每路SPI上可能接有不同的从设备通信频率、模式等可能不同
* @spi_base 基地址
* @tx_ch 待发送的数据
* @ret 收到的数据
*/
unsigned char ls1c_spi_txrx_byte(void *spi_base, unsigned char tx_ch)
{
unsigned char rx_ch = 0;
// 收发数据
reg_write_8(tx_ch, spi_base + LS1C_SPI_TxFIFO_OFFSET); // 开始发送
ls1c_spi_wait_txrx_done(spi_base); // 等待收发完成
rx_ch = reg_read_8(spi_base + LS1C_SPI_RxFIFO_OFFSET); // 读取收到的数据
ls1c_spi_clear(spi_base); // 清中断和标志位
return rx_ch;
}