296 lines
7.2 KiB
C
296 lines
7.2 KiB
C
/*
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* File : ls1c_spi.c
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Change Logs:
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* Date Author Notes
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* 2017-10-23 勤为本 first version
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*/
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// 硬件spi接口源文件
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#include <string.h>
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#include "ls1c_public.h"
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#include "ls1c_regs.h"
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#include "ls1c_clock.h"
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#include "ls1c_spi.h"
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/*
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* 获取指定SPI模块的基地址
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* @SPIx SPI模块的编号
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*/
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inline void *ls1c_spi_get_base(unsigned char SPIx)
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{
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void *base = NULL;
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switch (SPIx)
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{
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case LS1C_SPI_0:
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base = (void *)LS1C_SPI0_BASE;
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break;
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case LS1C_SPI_1:
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base = (void *)LS1C_SPI1_BASE;
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break;
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default:
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base = NULL;
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break;
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}
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return base;
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}
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/*
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* 打印指定SPI模块的所有寄存器的值
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* @spi_base 基地址
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*/
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void ls1c_spi_print_all_regs_info(void *spi_base)
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{
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rt_kprintf("[%s] SPCR=0x%x, SPSR=0x%x, SPER=0x%x, SFC_PARAM=0x%x, SFC_SOFTCS=0x%x, SFC_TIMING=0x%x\r\n",
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__FUNCTION__,
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reg_read_8(spi_base + LS1C_SPI_SPCR_OFFSET),
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reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET),
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reg_read_8(spi_base + LS1C_SPI_SPER_OFFSET),
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reg_read_8(spi_base + LS1C_SPI_SFC_PARAM_OFFSET),
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reg_read_8(spi_base + LS1C_SPI_SFC_SOFTCS_OFFSET),
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reg_read_8(spi_base + LS1C_SPI_SFC_TIMING_OFFSET));
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return ;
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}
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/*
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* 根据SPI时钟频率计算分频系数
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* @max_speed_hz SPI最大通信速度
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* @ret 分频系数
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*/
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unsigned int ls1c_spi_get_div(unsigned int max_speed_hz)
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{
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unsigned long clk = 0;
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unsigned int div = 0;
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unsigned int div_tmp = 0;
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unsigned int bit = 0;
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clk = clk_get_apb_rate();
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div = DIV_ROUND_UP(clk, max_speed_hz);
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if (div < 2)
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div = 2;
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if (div > 4096)
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div = 4096;
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bit = ls1c_fls(div) - 1;
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switch (1 << bit)
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{
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case 16:
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div_tmp = 2;
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if (div > (1 << bit))
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{
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div_tmp++;
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}
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break;
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case 32:
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div_tmp = 3;
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if (div > (1 << bit))
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{
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div_tmp += 2;
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}
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break;
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case 8:
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div_tmp = 4;
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if (div > (1 << bit))
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{
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div_tmp -= 2;
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}
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break;
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default:
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div_tmp = bit - 1;
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if (div > (1 << bit))
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{
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div_tmp++;
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}
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break;
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}
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/*
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rt_kprintf("[%s] clk=%ld, max_speed_hz=%d, div_tmp=%d, bit=%d\r\n",
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__FUNCTION__, clk, max_speed_hz, div_tmp, bit);
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*/
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return div_tmp;
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}
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/*
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* 设置时钟
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* @spi_base 基地址
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* @max_hz 最大频率，单位hz
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*/
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void ls1c_spi_set_clock(void *spi_base, unsigned long max_hz)
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{
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unsigned int div = 0;
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unsigned char val = 0;
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// 获取分频系数
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div = ls1c_spi_get_div(max_hz);
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// 设置spr
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val = reg_read_8(spi_base + LS1C_SPI_SPCR_OFFSET);
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val &= (~LS1C_SPI_SPCR_SPR_MASK); // spr清零
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val |= (div & LS1C_SPI_SPCR_SPR_MASK); // 设置新的spr
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reg_write_8(val, spi_base + LS1C_SPI_SPCR_OFFSET);
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// 设置spre
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val = reg_read_8(spi_base + LS1C_SPI_SPER_OFFSET);
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val &= (~LS1C_SPI_SPER_SPRE_MASK); // spre清零
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val |= ((div >> 2) & LS1C_SPI_SPER_SPRE_MASK); // 设置新的spre
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reg_write_8(val, spi_base + LS1C_SPI_SPER_OFFSET);
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return ;
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}
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/*
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* 设置通信模式(时钟极性和相位)
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* @spi_base 基地址
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* @cpol 时钟极性
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* @cpha 时钟相位
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*/
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void ls1c_spi_set_mode(void *spi_base, unsigned char cpol, unsigned char cpha)
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{
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unsigned char val = 0;
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val = reg_read_8(spi_base + LS1C_SPI_SPCR_OFFSET);
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// 设置时钟极性--cpol
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val &= (~LS1C_SPI_SPCR_CPOL_MASK); // cpol清0
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val |= (cpol << LS1C_SPI_SPCR_CPOL_BIT); // 写入新的cpol
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// 设置时钟相位--cpha
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val &= (~LS1C_SPI_SPCR_CPHA_MASK); // cpha清0
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val |= (cpha << LS1C_SPI_SPCR_CPHA_BIT); // 写入新的cpha
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reg_write_8(val, spi_base + LS1C_SPI_SPCR_OFFSET);
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return ;
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}
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/*
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* 设置指定片选为指定状态
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* @spi_base 基地址
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* @cs 片选
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* @new_status 片选引脚的新状态，取值为0或1，即高电平或低电平
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*/
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void ls1c_spi_set_cs(void *spi_base, unsigned char cs, int new_status)
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{
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unsigned char val = 0;
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val = 0xf0 | (0x01 << cs); // 全部csn=1，指定的csen=1
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if (new_status) // cs = 1
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{
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val |= (0x10 << cs); // 指定csn=1
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}
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else // cs = 0
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{
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val &= ~(0x10 << cs); // 指定csn=0
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}
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reg_write_8(val, spi_base + LS1C_SPI_SFC_SOFTCS_OFFSET);
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return ;
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}
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/*
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* 等待收发完成
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* @spi_base 基地址
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*/
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inline void ls1c_spi_wait_txrx_done(void *spi_base)
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{
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int timeout = LS1C_SPI_TX_TIMEOUT;
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while (timeout--)
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{
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if (LS1C_SPI_SPSR_SPIF_MASK & reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET))
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break;
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}
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return ;
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}
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/*
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* 清中断和标志位
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* @spi_base 基地址
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*/
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inline void ls1c_spi_clear(void *spi_base)
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{
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unsigned char val = 0;
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// 清中断
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val = reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET);
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val |= LS1C_SPI_SPSR_SPIF_MASK;
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reg_write_8(val, spi_base + LS1C_SPI_SPSR_OFFSET);
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// 清溢出标志位(Write-Collision Clear)
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val = reg_read_8(spi_base + LS1C_SPI_SPSR_OFFSET);
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if (LS1C_SPI_SPSR_WCOL_MASK & val)
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{
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rt_kprintf("[%s] clear register SPSR's wcol!\r\n"); // 手册和linux源码中不一样，加个打印看看
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reg_write_8(val & ~LS1C_SPI_SPSR_WCOL_MASK, spi_base + LS1C_SPI_SPSR_OFFSET); // 写0，linux源码中是写0
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// 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
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}
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return ;
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}
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/*
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* 通过指定SPI发送接收一个字节
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* 注意，在多任务的系统中，此函数需要互斥。
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* 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
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* 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
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* @spi_base 基地址
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* @tx_ch 待发送的数据
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* @ret 收到的数据
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*/
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unsigned char ls1c_spi_txrx_byte(void *spi_base, unsigned char tx_ch)
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{
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unsigned char rx_ch = 0;
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// 收发数据
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reg_write_8(tx_ch, spi_base + LS1C_SPI_TxFIFO_OFFSET); // 开始发送
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ls1c_spi_wait_txrx_done(spi_base); // 等待收发完成
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rx_ch = reg_read_8(spi_base + LS1C_SPI_RxFIFO_OFFSET); // 读取收到的数据
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ls1c_spi_clear(spi_base); // 清中断和标志位
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return rx_ch;
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}
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