基于RT-Thread的SPI通讯-rtthreadfinsh移植问题

sdk 目前还不支持 spi，没有 spi 就失去了很多乐趣，如 easyflash、spi 的屏幕，蓝讯的这次活动我接到了模拟 spi 的任务，下面介绍如何写 rt-thread 的设备驱动层的驱动。（rt-thread的设备 I/O 模型有设备管理层、设备驱动框架层、设备驱动层），我写过一篇使用 timer 的，就属于最接近用户那一层-设备管理层，我们调用 rt_device_find 根据名称查找句柄，之后根据句柄执行 rt_device_read、rt_device_write、rt_device_control 语句完成与底层设备的交互，而最底层的 timer 已经由中科蓝讯的工程师完成了。而这次的模拟 spi 则是写设备驱动层。

设备驱动层的编写有两步：

实现 spi 的驱动程序（模拟 spi 主要通过 io 口模拟 spi 的时序）将裸机程序按 rt-thread 的设备驱动框架封装（主要是自己写的函数原型与 rt-thread 的接口对应上）

在 library 下添加 drv_soft_spi.c 和 drv_soft_spi.h

复制3.1 drv_soft_spi.c /* * Change Logs: * Date Author Notes * 2021-06-03 qwz first version */ #include “board.h” #ifdef RT_USING_SPI #ifdef RT_SPI_SOFT #include “spi.h” #include “drv_soft_spi.h” #include #define DRV_DEBUG #define LOG_TAG “drv.spisoft” #include enum{ #ifdef BSP_USING_SOFT_SPI1 SOFT_SPI1_INDEX, #endif }; //PB2 10 ;PE5 18;PE6 19;PB1 9; #define SOFT_SPI1_BUS_CONFIG { \ .mosi_pin = 18, \ .miso_pin = 10, \ .sclk_pin = 9, \ .bus_name = “spi0”, \ } static struct ab32_soft_spi_config soft_spi_config[] ={ #ifdef BSP_USING_SOFT_SPI1 SOFT_SPI1_BUS_CONFIG, #endif }; static struct ab32_soft_spi soft_spi_bus_obj[sizeof(soft_spi_config) / sizeof(soft_spi_config[0])] = {0}; static rt_err_t ab32_spi_init(struct ab32_soft_spi *spi_drv, struct rt_spi_configuration *cfg){ RT_ASSERT(spi_drv != RT_NULL); RT_ASSERT(cfg != RT_NULL); //mode = master if (cfg->mode & RT_SPI_SLAVE){ return RT_EIO; } else spi_drv->mode = RT_SPI_MASTER; if (cfg->mode & RT_SPI_3WIRE){ return RT_EIO; } if (cfg->data_width == 8 || cfg->data_width == 16) spi_drv->data_width = cfg->data_width; else{ return RT_EIO; } if (cfg->mode & RT_SPI_CPHA){ spi_drv->cpha = 1; } else{ spi_drv->cpha = 0; } if (cfg->mode & RT_SPI_CPOL){ spi_drv->cpol = 1; } else{ spi_drv->cpol = 0; } if (cfg->mode & RT_SPI_NO_CS){ } else{ } if (cfg->max_hz >= 1200000){ spi_drv->spi_delay = 0; }else if (cfg->max_hz >= 1000000){ spi_drv->spi_delay = 8; }else if (cfg->max_hz >= 830000){ spi_drv->spi_delay = 16; } else { spi_drv->spi_delay = 24; } LOG_D(“SPI limiting freq: %d, BaudRatePrescaler: %d”, cfg->max_hz, spi_drv->max_hz); if (cfg->mode & RT_SPI_MSB){ spi_drv->msb = 1; } else{ spi_drv->msb = 0; } rt_pin_mode(spi_drv->config->mosi_pin,PIN_MODE_OUTPUT_OD); rt_pin_write(spi_drv->config->mosi_pin,PIN_HIGH); rt_pin_mode(spi_drv->config->miso_pin,PIN_MODE_INPUT_PULLDOWN); rt_pin_mode(spi_drv->config->sclk_pin,PIN_MODE_OUTPUT_OD); if(spi_drv->cpol) rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); else rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); LOG_D(“%s init done”, spi_drv->config->bus_name); return RT_EOK; } static inline void spi_delay(rt_uint32_t us){ rt_thread_mdelay(us); } static rt_uint32_t soft_spi_read_write_bytes(struct ab32_soft_spi *spi_drv, rt_uint8_t* send_buff, rt_uint8_t* recv_buff, rt_uint32_t len){ rt_uint8_t dataIndex = 0; rt_uint8_t time = 1; for(rt_uint32_t i = 0; icpha){ //CPHA=1 if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } } if(spi_drv->data_width == 16) time = 2; do{ for(rt_uint8_t j = 0; j < 8; j++){ if ((send_buff[dataIndex] & 0x80) != 0){ rt_pin_write(spi_drv->config->mosi_pin,PIN_HIGH); }else{ rt_pin_write(spi_drv->config->mosi_pin,PIN_LOW); } send_buff[dataIndex] <<= 1; spi_delay(spi_drv->spi_delay); if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } recv_buff[dataIndex] <<= 1; if (rt_pin_read(spi_drv->config->miso_pin)) recv_buff[dataIndex] |= 0x01; spi_delay(spi_drv->spi_delay); if(time != 0 || j != 7){ if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } } } dataIndex++; }while((–time)==1); time = 1; spi_delay(spi_drv->spi_delay); } return len; } static rt_uint32_t soft_spi_read_bytes(struct ab32_soft_spi *spi_drv, rt_uint8_t* recv_buff, rt_uint32_t len){ rt_uint8_t send_buff = spi_drv->dummy_data; rt_uint32_t dataIndex = 0; rt_uint8_t time = 1; if(spi_drv->cpha){ //CPHA=1 if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } } for(rt_uint32_t i = 0; idata_width == 16) time = 2; do{ for(rt_uint8_t j = 0; j < 8; j++){ if ((send_buff & 0x80) != 0){ rt_pin_write(spi_drv->config->mosi_pin,PIN_HIGH); }else{ rt_pin_write(spi_drv->config->mosi_pin,PIN_LOW); } send_buff <<= 1; spi_delay(spi_drv->spi_delay); if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } *recv_buff <<= 1; if (rt_pin_read(spi_drv->config->miso_pin)) { *recv_buff |= 0x01; } else { *recv_buff &= 0xfe; } spi_delay(spi_drv->spi_delay); if(time != 0 || j != 7){ if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } } } recv_buff ++; dataIndex++; }while((–time)==1); time = 1; spi_delay(spi_drv->spi_delay); LOG_D(“DONE ONE BYTE %d”,dataIndex); LOG_D(“%d”,spi_drv->spi_delay); } return len; } static rt_uint32_t soft_spi_write_bytes(struct ab32_soft_spi *spi_drv, rt_uint8_t* send_buff, rt_uint32_t len){ rt_uint8_t recv_buff = 0; rt_uint32_t dataIndex = 0; rt_uint8_t time = 1; LOG_D(“%x”,send_buff[0]); if(spi_drv->cpha){ //CPHA=1 if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } } for(uint32_t i = 0; idata_width == 16) time = 2; do{ for(rt_uint8_t j = 0; j < 8; j++){ if ((send_buff[dataIndex] & 0x80) != 0){ rt_pin_write(spi_drv->config->mosi_pin,PIN_HIGH); LOG_D(“PIN_HIGH”); }else{ rt_pin_write(spi_drv->config->mosi_pin,PIN_LOW); LOG_D(“PIN_LOW”); } send_buff[dataIndex] <<= 1; spi_delay(spi_drv->spi_delay); if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } recv_buff <<= 1; if (rt_pin_read(spi_drv->config->miso_pin)) recv_buff |= 0x01; spi_delay(spi_drv->spi_delay); if(time != 0 || j != 7){ if(rt_pin_read(spi_drv->config->sclk_pin)) { rt_pin_write(spi_drv->config->sclk_pin,PIN_LOW); } else { rt_pin_write(spi_drv->config->sclk_pin,PIN_HIGH); } } } dataIndex++; }while((–time)==1); time = 1; spi_delay(spi_drv->spi_delay); } return len; } static rt_uint32_t spixfer(struct rt_spi_device *device, struct rt_spi_message *message){ rt_uint32_t state; rt_size_t message_length; rt_uint8_t *recv_buf; const rt_uint8_t *send_buf; rt_uint8_t pin = rt_pin_get(“PE.6”); RT_ASSERT(device != RT_NULL); RT_ASSERT(device->bus != RT_NULL); RT_ASSERT(device->bus->parent.user_data != RT_NULL); RT_ASSERT(message != RT_NULL); struct ab32_soft_spi *spi_drv = rt_container_of(device->bus, struct ab32_soft_spi, spi_bus); struct ab32_soft_spi_pin *cs = device->parent.user_data; if (message->cs_take){ rt_pin_write(cs->GPIO_Pin,PIN_LOW); } LOG_D(“%s transfer prepare and start”, spi_drv->config->bus_name); LOG_D(“%s sendbuf: %02x, recvbuf: %02x, length: %d”, spi_drv->config->bus_name, (message->send_buf), ((rt_uint8_t *)(message->recv_buf)), message->length); message_length = message->length; recv_buf = message->recv_buf; send_buf = message->send_buf; if(message_length){ if (message->send_buf && message->recv_buf){ state = soft_spi_read_write_bytes(spi_drv, (rt_uint8_t *)send_buf, (rt_uint8_t *)recv_buf, message_length); LOG_D(“soft_spi_read_write_bytes”); } else if (message->send_buf){ state = soft_spi_write_bytes(spi_drv, (rt_uint8_t *)send_buf, message_length); LOG_D(“soft_spi_write_bytes”); } else{ memset((rt_uint8_t *)recv_buf, 0x00, message_length); state = soft_spi_read_bytes(spi_drv, (rt_uint8_t *)recv_buf, message_length); LOG_D(“soft_spi_read_bytes”); } if (state != message_length){ LOG_I(“spi transfer error : %d”, state); message->length = 0; } else{ LOG_D(“%s transfer done”, spi_drv->config->bus_name); } } if (message->cs_release){ rt_pin_write(cs->GPIO_Pin,PIN_HIGH); } return message->length; } static rt_err_t spi_configure(struct rt_spi_device *device, struct rt_spi_configuration *configuration){ RT_ASSERT(device != RT_NULL); RT_ASSERT(configuration != RT_NULL); struct ab32_soft_spi *spi_drv = rt_container_of(device->bus, struct ab32_soft_spi, spi_bus); spi_drv->cfg = configuration; return ab32_spi_init(spi_drv, configuration); } static const struct rt_spi_ops ab32_spi_ops ={ .configure = spi_configure, .xfer = spixfer, }; static int rt_soft_spi_bus_init(void){ rt_err_t result; for (int i = 0; i < sizeof(soft_spi_config) / sizeof(soft_spi_config[0]); i++){ soft_spi_bus_obj[i].config = &soft_spi_config[i]; soft_spi_bus_obj[i].spi_bus.parent.user_data = &soft_spi_config[i]; result = rt_spi_bus_register(&soft_spi_bus_obj[i].spi_bus, soft_spi_config[i].bus_name, &ab32_spi_ops); RT_ASSERT(result == RT_EOK); LOG_D(“%s bus init done”, soft_spi_config[i].bus_name); } return result; } /** * Attach the spi device to SPI bus, this function must be used after initialization. */ rt_err_t rt_soft_spi_device_attach(const char *bus_name, const char *device_name, hal_sfr_t cs_gpiox, rt_uint8_t cs_gpio_pin){ RT_ASSERT(bus_name != RT_NULL); RT_ASSERT(device_name != RT_NULL); rt_err_t result; struct rt_spi_device *spi_device; struct ab32_soft_spi_pin *cs_pin; /* attach the device to spi bus*/ spi_device = (struct rt_spi_device *)rt_malloc(sizeof(struct rt_spi_device)); RT_ASSERT(spi_device != RT_NULL); cs_pin = (struct ab32_soft_spi_pin *)rt_malloc(sizeof(struct ab32_soft_spi_pin)); RT_ASSERT(cs_pin != RT_NULL); cs_pin->GPIOx = cs_gpiox; cs_pin->GPIO_Pin = cs_gpio_pin; rt_pin_mode(cs_pin->GPIO_Pin, PIN_MODE_OUTPUT); result = rt_spi_bus_attach_device(spi_device, device_name, bus_name, (void *)cs_pin); if (result != RT_EOK){ LOG_E(“%s attach to %s faild, %d\n”, device_name, bus_name, result); } RT_ASSERT(result == RT_EOK); LOG_D(“%s attach to %s done”, device_name, bus_name); return result; } int rt_soft_spi_init(void){ return rt_soft_spi_bus_init(); } INIT_BOARD_EXPORT(rt_soft_spi_init); #endif #endif /* RT_USING_SPI */;>;>;>

审核编辑 黄昊宇