/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2020-01-09     shelton      first version
 */
 
#include <board.h>
#include "drv_spi.h"

#ifdef RT_USING_SPI
#if !defined(BSP_USING_SPI1) && !defined(BSP_USING_SPI2) && \
    !defined(BSP_USING_SPI3) && !defined(BSP_USING_SPI4)
#error "Please define at least one SPIx"
#endif

//#define DEBUG

#define ARR_LEN(__N)      (sizeof(__N) / sizeof(__N[0]))

#ifdef DEBUG
#define DEBUG_PRINTF(...)   rt_kprintf(__VA_ARGS__)
#else
#define DEBUG_PRINTF(...)   
#endif

/* private rt-thread spi ops function */
static rt_err_t configure(struct rt_spi_device* device, struct rt_spi_configuration* configuration);
static rt_uint32_t xfer(struct rt_spi_device* device, struct rt_spi_message* message);

static struct rt_spi_ops at32_spi_ops =
{
    configure,
    xfer
};

/**
  * Attach the spi device to SPI bus, this function must be used after initialization.
  */
rt_err_t rt_hw_spi_device_attach(const char *bus_name, const char *device_name, GPIO_Type *cs_gpiox, uint16_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 at32_spi_cs *cs_pin;

    /* initialize the cs pin && select the slave*/
    GPIO_InitType GPIO_InitStruct;
    GPIO_InitStruct.GPIO_Pins = cs_gpio_pin;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT_PP;
    GPIO_InitStruct.GPIO_MaxSpeed = GPIO_MaxSpeed_50MHz;
    GPIO_Init(cs_gpiox, &GPIO_InitStruct);
    GPIO_SetBits(cs_gpiox, cs_gpio_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 at32_spi_cs *)rt_malloc(sizeof(struct at32_spi_cs));
    RT_ASSERT(cs_pin != RT_NULL);
    cs_pin->GPIOx = cs_gpiox;
    cs_pin->GPIO_Pin = cs_gpio_pin;
    result = rt_spi_bus_attach_device(spi_device, device_name, bus_name, (void *)cs_pin);

    if (result != RT_EOK)
    {
        DEBUG_PRINTF("%s attach to %s faild, %d\n", device_name, bus_name, result);
    }

    RT_ASSERT(result == RT_EOK);

    DEBUG_PRINTF("%s attach to %s done", device_name, bus_name);

    return result;
}

static rt_err_t configure(struct rt_spi_device* device,
                          struct rt_spi_configuration* configuration)
{
    struct rt_spi_bus * spi_bus = (struct rt_spi_bus *)device->bus;	
    struct at32_spi *spi_instance = (struct at32_spi *)spi_bus->parent.user_data;
    
    SPI_InitType SPI_InitStruct;

	  RT_ASSERT(device != RT_NULL);
	  RT_ASSERT(configuration != RT_NULL);

    at32_msp_spi_init(spi_instance->config->spix);

    /* data_width */
    if(configuration->data_width <= 8)
    {
        SPI_InitStruct.SPI_FrameSize = SPI_FRAMESIZE_8BIT;
    }
    else if(configuration->data_width <= 16)
    {
        SPI_InitStruct.SPI_FrameSize = SPI_FRAMESIZE_16BIT;
    }
    else
    {
        return RT_EIO;
    }

    /* baudrate */
    {
        uint32_t spi_apb_clock;
        uint32_t max_hz;
        RCC_ClockType  RCC_Clocks;

        max_hz = configuration->max_hz;

        RCC_GetClocksFreq(&RCC_Clocks);
        DEBUG_PRINTF("sys   freq: %d\n", RCC_Clocks.SYSCLK_Freq);
        DEBUG_PRINTF("max   freq: %d\n", max_hz);

        if (spi_instance->config->spix == SPI1)
        {
            spi_apb_clock = RCC_Clocks.APB2CLK_Freq;
            DEBUG_PRINTF("pclk2 freq: %d\n", RCC_Clocks.APB2CLK_Freq);
        }
        else
        {
            spi_apb_clock = RCC_Clocks.APB1CLK_Freq;
            DEBUG_PRINTF("pclk1 freq: %d\n", RCC_Clocks.APB1CLK_Freq);
        }

        if(max_hz >= spi_apb_clock/2)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_2;
        }
        else if (max_hz >= spi_apb_clock/4)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_4;
        }
        else if (max_hz >= spi_apb_clock/8)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_8;
        }
        else if (max_hz >= spi_apb_clock/16)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_16;
        }
        else if (max_hz >= spi_apb_clock/32)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_32;
        }
        else if (max_hz >= spi_apb_clock/64)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_64;
        }
        else if (max_hz >= spi_apb_clock/128)
        {
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_128;
        }
        else
        {
            /*  min prescaler 256 */
            SPI_InitStruct.SPI_MCLKP = SPI_MCLKP_256;
        }
    } /* baudrate */
    
    switch(configuration->mode & RT_SPI_MODE_3)
    {
    case RT_SPI_MODE_0:
        SPI_InitStruct.SPI_CPHA = SPI_CPHA_1EDGE;
        SPI_InitStruct.SPI_CPOL = SPI_CPOL_LOW;
        break;
    case RT_SPI_MODE_1:
        SPI_InitStruct.SPI_CPHA = SPI_CPHA_2EDGE;
        SPI_InitStruct.SPI_CPOL = SPI_CPOL_LOW;
        break;        
    case RT_SPI_MODE_2:
        SPI_InitStruct.SPI_CPHA = SPI_CPHA_1EDGE;
        SPI_InitStruct.SPI_CPOL = SPI_CPOL_HIGH;
        break;    
    case RT_SPI_MODE_3:
        SPI_InitStruct.SPI_CPHA = SPI_CPHA_2EDGE;
        SPI_InitStruct.SPI_CPOL = SPI_CPOL_HIGH;
        break;
    }

    /* MSB or LSB */
    if(configuration->mode & RT_SPI_MSB)
    {
        SPI_InitStruct.SPI_FirstBit = SPI_FIRSTBIT_MSB;
    }
    else
    {
        SPI_InitStruct.SPI_FirstBit = SPI_FIRSTBIT_LSB;
    }

    SPI_InitStruct.SPI_TransMode = SPI_TRANSMODE_FULLDUPLEX;
    SPI_InitStruct.SPI_Mode = SPI_MODE_MASTER;
    SPI_InitStruct.SPI_NSSSEL = SPI_NSSSEL_SOFT;

    /* init SPI */
    SPI_Init(spi_instance->config->spix, &SPI_InitStruct);
    /* Enable SPI_MASTER */
	  SPI_Enable(spi_instance->config->spix, ENABLE);
    SPI_CRCEN(spi_instance->config->spix, DISABLE);

    return RT_EOK;
};

static rt_uint32_t xfer(struct rt_spi_device* device, struct rt_spi_message* message)
{
    struct rt_spi_bus * at32_spi_bus = (struct rt_spi_bus *)device->bus;
    struct at32_spi *spi_instance = (struct at32_spi *)at32_spi_bus->parent.user_data;
    struct rt_spi_configuration * config = &device->config;
    struct at32_spi_cs * at32_spi_cs = device->parent.user_data;

	  RT_ASSERT(device != NULL);
	  RT_ASSERT(message != NULL);
	
    /* take CS */
    if(message->cs_take)
    {
        GPIO_ResetBits(at32_spi_cs->GPIOx, at32_spi_cs->GPIO_Pin);
        DEBUG_PRINTF("spi take cs\n");
    }

    {
        if(config->data_width <= 8)
        {
            const rt_uint8_t * send_ptr = message->send_buf;
            rt_uint8_t * recv_ptr = message->recv_buf;
            rt_uint32_t size = message->length;
            
            DEBUG_PRINTF("spi poll transfer start: %d\n", size);

            while(size--)
            {
                rt_uint8_t data = 0xFF;

                if(send_ptr != RT_NULL)
                {
                    data = *send_ptr++;
                }
                
                // Todo: replace register read/write by at32 lib
                //Wait until the transmit buffer is empty
                while(RESET == SPI_I2S_GetFlagStatus(spi_instance->config->spix, SPI_I2S_FLAG_TE));
                // Send the byte
				        SPI_I2S_TxData(spi_instance->config->spix, data);

                //Wait until a data is received
                while(RESET == SPI_I2S_GetFlagStatus(spi_instance->config->spix, SPI_I2S_FLAG_RNE));
                // Get the received data
                data = SPI_I2S_RxData(spi_instance->config->spix);

                if(recv_ptr != RT_NULL)
                {
                    *recv_ptr++ = data;
                }
            }
            DEBUG_PRINTF("spi poll transfer finsh\n");
        }
        else if(config->data_width <= 16)
        {
            const rt_uint16_t * send_ptr = message->send_buf;
            rt_uint16_t * recv_ptr = message->recv_buf;
            rt_uint32_t size = message->length;

            while(size--)
            {
                rt_uint16_t data = 0xFF;

                if(send_ptr != RT_NULL)
                {
                    data = *send_ptr++;
                }

                //Wait until the transmit buffer is empty
                while(RESET == SPI_I2S_GetFlagStatus(spi_instance->config->spix, SPI_I2S_FLAG_TE));
                // Send the byte
				        SPI_I2S_TxData(spi_instance->config->spix, data);

                //Wait until a data is received
                while(RESET == SPI_I2S_GetFlagStatus(spi_instance->config->spix, SPI_I2S_FLAG_RNE));
                // Get the received data
                data = SPI_I2S_RxData(spi_instance->config->spix);

                if(recv_ptr != RT_NULL)
                {
                    *recv_ptr++ = data;
                }
            }
        }
    }

    /* release CS */
    if(message->cs_release)
    {
		    GPIO_SetBits(at32_spi_cs->GPIOx, at32_spi_cs->GPIO_Pin);
        DEBUG_PRINTF("spi release cs\n");
    }

    return message->length;
};

static struct at32_spi_config configs[] = {
#ifdef BSP_USING_SPI1
    {SPI1, "spi1"},
#endif
    
#ifdef BSP_USING_SPI2
    {SPI2, "spi2"},
#endif

#ifdef BSP_USING_SPI3
    {SPI3, "spi3"},
#endif

#ifdef BSP_USING_SPI4
    {SPI4, "spi4"},
#endif
};

static struct at32_spi spis[sizeof(configs) / sizeof(configs[0])] = {0};

/** \brief init and register at32 spi bus.
 *
 * \param SPI: at32 SPI, e.g: SPI1,SPI2,SPI3.
 * \param spi_bus_name: spi bus name, e.g: "spi1"
 * \return
 *
 */
int rt_hw_spi_init(void)
{
    int i;
    rt_err_t result;
    rt_size_t obj_num = sizeof(spis) / sizeof(struct at32_spi);

    for (i = 0; i < obj_num; i++)
    {
        spis[i].config = &configs[i];
        spis[i].spi_bus.parent.user_data = (void *)&spis[i];
        result = rt_spi_bus_register(&(spis[i].spi_bus), spis[i].config->spi_name, &at32_spi_ops);
    }

    return result;
}

INIT_BOARD_EXPORT(rt_hw_spi_init);

#endif