/* * File : ls1c_spi.c * This file is part of RT-Thread RTOS * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * Change Logs: * Date Author Notes * 2017-10-23 勤为本 first version */ // 硬件spi接口源文件 #include #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 */ inline 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) { 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", __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; } /* rt_kprintf("[%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 */ inline 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 */ inline 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) { 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 reg_write_8(val & ~LS1C_SPI_SPSR_WCOL_MASK, spi_base + LS1C_SPI_SPSR_OFFSET); // 写0，linux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; }