【T113】【spi 驱动】【大数据DMA传输】

shiguojie1989 LV 3

1.需求：通过gsip引脚接收来自fpga的数据等待接收中断，然后中断到来后，113的spi驱动为主控读取fpga的spi数据，数据量12800字节，驱动设置了10个缓冲区映射内存，spi内次写入一个缓冲区。中断频率为25Hz。应用程序通过map映射会读取存在的10个里面的ok的缓冲区。
2.现状：驱动代码基于imx6ull linux4.9版本修改，驱动已经编译通过，并且可以使用read、write接口正常的进行spi通讯（1000字节以内）。但是如果是使用GPIS中断函数来完成spi的读取，调用同样的spi读写函数，spi不能正常工作，会提示：“Bufferless transfer has length ”，错误来自spi.c。（注意，gpio中断是fpga的引脚给T113的引脚，代码中通过中断函数触发spi的一次传输）
3.驱动文件是：fsfpgain.c；read、write测试app是：test_spidev.c；gpio中断来读取spi测试app是：test_fsfpgain.c
下面是三个文件的代码：
fsfpgain.c

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/of_gpio.h>
#include <linux/semaphore.h>
#include <linux/timer.h>
#include <linux/spi/spi.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/atomic.h>
#include <linux/irq.h>
#include <linux/of_irq.h>
#include <asm/mach/map.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/spi/spi.h>
#include <linux/spi/spidev.h>
#include <linux/acpi.h>
#include <linux/of_irq.h>
#include <asm/mach/map.h>
#include <asm/uaccess.h>
#include <asm/io.h>
/*
 * This supports access to SPI devices using normal userspace I/O calls.
 * Note that while traditional UNIX/POSIX I/O semantics are half duplex,
 * and often mask message boundaries, full SPI support requires full duplex
 * transfers.  There are several kinds of internal message boundaries to
 * handle chipselect management and other protocol options.
 *
 * SPI has a character major number assigned.  We allocate minor numbers
 * dynamically using a bitmask.  You must use hotplug tools, such as udev
 * (or mdev with busybox) to create and destroy the /dev/spidevB.C device
 * nodes, since there is no fixed association of minor numbers with any
 * particular SPI bus or device.
 */
#define SPIDEV_MAJOR			153	/* assigned */
#define N_SPI_MINORS			32	/* ... up to 256 */

static DECLARE_BITMAP(minors, N_SPI_MINORS);

/* Bit masks for spi_device.mode management.  Note that incorrect
 * settings for some settings can cause *lots* of trouble for other
 * devices on a shared bus:
 *
 *  - CS_HIGH ... this device will be active when it shouldn't be
 *  - 3WIRE ... when active, it won't behave as it should
 *  - NO_CS ... there will be no explicit message boundaries; this
 *	is completely incompatible with the shared bus model
 *  - READY ... transfers may proceed when they shouldn't.
 *
 * REVISIT should changing those flags be privileged?
 */
#define SPI_MODE_MASK		(SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
				| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
				| SPI_NO_CS | SPI_READY | SPI_TX_DUAL \
				| SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)

#define DMAC_CNLL_MAX_NUM           32
#define DMAC_ONE_TR_NUM             1000 //一次spi从fpga读取的大小
#define DMAC_MAX_TRF_SIZE           DMAC_CNLL_MAX_NUM*DMAC_ONE_TR_NUM
#define DMA_RECV_MAX_NUM            10//环形缓冲器大小
#define VER 0x20000113

#define NEXT_BUF(x) (((x+1) < DMA_RECV_MAX_NUM) ? (x+1) : 0)


struct mem_addr{
	char* v_adr;
	dma_addr_t p_adr;
};//内存物理地址和虚拟地址

//环形缓冲器，分块保存每个dma头物理地址
struct buffer_cut{
	unsigned int recv_num;
	unsigned int last_buf_len;//最后一块内存的长度
	dma_addr_t pr_buf_fpga[DMA_RECV_MAX_NUM][DMAC_CNLL_MAX_NUM];
};

struct spidev_data {
	dev_t			devt;
	spinlock_t		spi_lock;
	struct spi_device	*spi;
	struct list_head	device_entry;

	/* TX/RX buffers are NULL unless this device is open (users > 0) */
	struct mutex		buf_lock;
	unsigned		users;
	u8			*tx_buffer;
	u8			*rx_buffer;
	u32			speed_hz;
    
    /*connet app param*/
    struct spi_transfer	t;
    struct spi_message	m;
    struct buffer_cut *buf_cut;
    int irq_gpio;
    int irq_num; //fpga中断号
    struct mem_addr rxbuf;
    int spi_len;//spi dma 单次长度
	bool b_workflag;//工作状态
	bool b_printk;//调试打印状态
	unsigned int send_data_len;//与fpga通讯一次交换数据的长度
	struct semaphore spi_sema;//信号量 表示环形缓冲区内的可读数据量
	int recv_buf_no;//接收到的数据块号码
	int copy_recv_buf_no;//被复制的“接收到的数据块号码”防止被中断修改数据
	int read_buf_no;//可读取的数据块号码
};


static LIST_HEAD(device_list);
static DEFINE_MUTEX(device_list_lock);

static void init_p_buf_cut(struct spidev_data	*spidev);

static unsigned bufsiz = 40960;
module_param(bufsiz, uint, S_IRUGO);
MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");

/*-------------------------------------------------------------------------*/
/*add shiguojie */

static inline ssize_t
spidev_sync_write(struct spidev_data *spidev, size_t len);

static ssize_t
spidev_sync(struct spidev_data *spidev)
{
	int status;
	struct spi_device *spi;

	spin_lock_irq(&spidev->spi_lock);
	spi = spidev->spi;
	spin_unlock_irq(&spidev->spi_lock);

	if (spi == NULL)
		status = -ESHUTDOWN;
	else
		status = spi_sync(spi, &spidev->m);
    printk("fsfpgain: spidev_sync re-%d\n",status);
	if (status == 0)
		status = spidev->m.actual_length;

    printk("fsfpgain: spidev_sync %d-%d-%d\n",spidev->t.speed_hz,spidev->t.len,status);
	return status;
}

static inline ssize_t
spidev_sync_read(struct spidev_data *spidev, size_t len)
{
	struct spi_transfer	t = {
			.rx_buf		= spidev->rx_buffer,
			.len		= len,
			.speed_hz	= spidev->speed_hz,
		};
	spi_message_init(&spidev->m);
	spi_message_add_tail(&t, &spidev->m);
	return spidev_sync(spidev);
}

static void spi_fpga_recv(struct spidev_data* spidev)
{
	int i = 0;
    int status = -1;
    struct buffer_cut *_p = spidev->buf_cut;
    int _no = spidev->recv_buf_no;
	//gpio_set_value(fsfpgaindev.cs_gpio, 0);
    printk("fafpgain:spi_fpga_recv %d-%d",_p->recv_num,spidev->buf_cut->last_buf_len);
	mutex_lock(&spidev->buf_lock);
	for (i = 0; i < _p->recv_num; i++)
	{
        spidev_sync_write(spidev,DMAC_ONE_TR_NUM);        
        memcpy((void*)spidev->buf_cut->pr_buf_fpga[_no][i],spidev->rx_buffer,DMAC_ONE_TR_NUM);				
	}

	if(spidev->buf_cut->last_buf_len)
	{          
        spidev_sync_read(spidev,spidev->buf_cut->last_buf_len);
        memcpy((void*)spidev->buf_cut->pr_buf_fpga[_no][i],spidev->rx_buffer,spidev->buf_cut->last_buf_len);      
	}    
	mutex_unlock(&spidev->buf_lock);
}

static irqreturn_t irq_gpio_spi_handler(int irq, void *dev_id)
{
	//printk("irq_gpio_spi_handler run\r\n");
	return IRQ_WAKE_THREAD;
}
static irqreturn_t irq_gpio_spi_thread_func(int irq, void *data)
{
    struct spidev_data	*spidev = (struct spidev_data*)data;
    if(spidev->b_workflag)    
	{
	    printk("fsfpgain:irq_gpio rec buf[%d],add:%x\r\n",
        spidev->recv_buf_no,spidev->buf_cut->pr_buf_fpga[spidev->recv_buf_no][0]);
		spi_fpga_recv(spidev);//读取一次
		//fsfpgaindev.read_buf_no = fsfpgaindev.recv_buf_no;
		spidev->recv_buf_no = NEXT_BUF(spidev->recv_buf_no);//取出下个环形缓冲器编号
		up(&spidev->spi_sema);
        spidev->b_workflag = 0;//test 
	}
	return IRQ_HANDLED;
}
void setSpidev_data(struct spidev_data *spidev)
{
    int ret = 0;
    spidev->speed_hz = 10000000;
    spidev->t.speed_hz = spidev->speed_hz;
    spidev->b_workflag = 0;//初始化工作状态为不工作
	spidev->send_data_len = 0;//初始化spi收发数据长度为0
	spidev->recv_buf_no = 0;
	spidev->read_buf_no = 0;
	spidev->copy_recv_buf_no = 0;
    spidev->spi->mode = SPI_MODE_1;
    ret = spi_setup(spidev->spi);
    printk("fsfpgain:spi_setup re:%d\n",ret);
//set map
    spidev->buf_cut = kzalloc(sizeof(struct buffer_cut), GFP_KERNEL);
	printk("fsfpgain:rxvadr value:0x%lx padr:0x%x\r\n",(long)spidev->rxbuf.v_adr,spidev->rxbuf.p_adr);
	printk("fsfpgain:rxvadr  addr:0x%lx padr:0x%x\r\n",(long)&spidev->rxbuf.v_adr,&spidev->rxbuf.p_adr);

    if((dma_set_coherent_mask(&spidev->spi->dev,DMA_BIT_MASK(32))) != 0)
    {
        dev_err(&spidev->spi->dev,"Failed to set 32-bit DMA mask\n");
        return -ENODEV;
    }
	spidev->rxbuf.v_adr = dma_alloc_coherent(&spidev->spi->dev,DMAC_MAX_TRF_SIZE*DMA_RECV_MAX_NUM,&spidev->rxbuf.p_adr,GFP_KERNEL|GFP_DMA);
	
//set irq
    struct device_node *nd = of_get_parent(spidev->spi->dev.of_node);    
    struct device_node *child;
	if(NULL == nd){
		printk("fsfpgain:nd get error\r\n");
	}else
    {
        
        printk("fsfpgain:Child scan\r\n");
        for_each_child_of_node(nd, child) 
        {
            printk("Child node name: %s\r\n", of_node_full_name(child));
            break;
        }              
	}
    spidev->irq_gpio  = of_get_named_gpio(child, "irq-gpio", 0);
	if (spidev->irq_gpio < 0)
	{	
		printk("fsfpgaindev.irq_gpio get error\r\n");
	}
    
    ret = gpio_request(spidev->irq_gpio, "irq_gpio");
    if(0 == ret)
	    printk("fsfpgain:gpio request irq gpio ok\r\n");
    else
	    printk("fsfpgain:gpio request ret:%d\r\n",ret);

	gpio_direction_input(spidev->irq_gpio);    
	spidev->irq_num = gpio_to_irq(spidev->irq_gpio);
    ret = request_threaded_irq(spidev->irq_num, irq_gpio_spi_handler,irq_gpio_spi_thread_func,IRQF_TRIGGER_RISING, "irq_gpio", spidev);
	
    if(0 > ret)
	{	
		printk("request_irq error\r\n");
	}
    else
    {
        printk("fsfpgain irq_num:%d\n",spidev->irq_num);
    }
    return;
}

void resetSpidev_data(struct spidev_data *spidev)
{    
	free_irq(spidev->irq_num, spidev);
	gpio_direction_output(spidev->irq_gpio, 0);
	gpio_free(spidev->irq_gpio);
    printk("fsfpgain:gpio_free\r\n");
    kfree(spidev->buf_cut);
	dma_free_coherent(&spidev->spi->dev,DMAC_MAX_TRF_SIZE*DMA_RECV_MAX_NUM,spidev->rxbuf.v_adr, spidev->rxbuf.p_adr);	
}
/*add shiguojie end*/

static inline ssize_t
spidev_sync_write(struct spidev_data *spidev, size_t len)
{
	struct spi_transfer	t = {
			.tx_buf		= spidev->tx_buffer,
            .rx_buf     = spidev->rx_buffer,//add by shiguojie
			.len		= len,
			.speed_hz	= spidev->speed_hz,
		};
    printk("fsfpgain:transfer len-%d speed-%d\r\n",len,spidev->speed_hz);
	spi_message_init(&spidev->m);
	spi_message_add_tail(&t, &spidev->m);
	return spidev_sync(spidev);
}

/*-------------------------------------------------------------------------*/

/* Read-only message with current device setup */
static ssize_t
spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
{
	struct spidev_data	*spidev;
	ssize_t			status = 0;

	/* chipselect only toggles at start or end of operation */
	if (count > bufsiz)
		return -EMSGSIZE;

	spidev = filp->private_data;

	mutex_lock(&spidev->buf_lock);
	status = spidev_sync_read(spidev, count);
	if (status > 0) {
		unsigned long	missing;

		missing = copy_to_user(buf, spidev->rx_buffer, status);
		if (missing == status)
			status = -EFAULT;
		else
			status = status - missing;
	}
	mutex_unlock(&spidev->buf_lock);

	return status;
}

/* Write-only message with current device setup */
static ssize_t
spidev_write(struct file *filp, const char __user *buf,
		size_t count, loff_t *f_pos)
{
    int x = 0;
	struct spidev_data	*spidev;
	ssize_t			status = 0;
	unsigned long		missing;
	/* chipselect only toggles at start or end of operation */
	if (count > bufsiz)
		return -EMSGSIZE;

	spidev = filp->private_data;

	mutex_lock(&spidev->buf_lock);
    char ttempBuf[1000];
    char rtempBuf[1000];
    spidev->tx_buffer = ttempBuf;
    spidev->rx_buffer = rtempBuf;
	missing = copy_from_user(spidev->tx_buffer, buf, count);
	if (missing == 0)
    {
		spidev_sync_write(spidev, count);
    }
	else
		status = -EFAULT;
	mutex_unlock(&spidev->buf_lock);

    printk("fsfpgain:write read:%s\n",spidev->rx_buffer);
	return status;
}

static int spidev_message(struct spidev_data *spidev,
		struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
{
	struct spi_transfer	*k_xfers;
	struct spi_transfer	*k_tmp;
	struct spi_ioc_transfer *u_tmp;
	unsigned		n, total, tx_total, rx_total;
	u8			*tx_buf, *rx_buf;
	int			status = -EFAULT;

	spi_message_init(&spidev->m);
	k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL);
	if (k_xfers == NULL)
		return -ENOMEM;

	/* Construct spi_message, copying any tx data to bounce buffer.
	 * We walk the array of user-provided transfers, using each one
	 * to initialize a kernel version of the same transfer.
	 */
	tx_buf = spidev->tx_buffer;
	rx_buf = spidev->rx_buffer;
	total = 0;
	tx_total = 0;
	rx_total = 0;
	for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
			n;
			n--, k_tmp++, u_tmp++) {
		/* Ensure that also following allocations from rx_buf/tx_buf will meet
		 * DMA alignment requirements.
		 */
		unsigned int len_aligned = ALIGN(u_tmp->len, ARCH_KMALLOC_MINALIGN);

		k_tmp->len = u_tmp->len;

		total += k_tmp->len;
		/* Since the function returns the total length of transfers
		 * on success, restrict the total to positive int values to
		 * avoid the return value looking like an error.  Also check
		 * each transfer length to avoid arithmetic overflow.
		 */
		if (total > INT_MAX || k_tmp->len > INT_MAX) {
			status = -EMSGSIZE;
			goto done;
		}

		if (u_tmp->rx_buf) {
			/* this transfer needs space in RX bounce buffer */
			rx_total += len_aligned;
			if (rx_total > bufsiz) {
				status = -EMSGSIZE;
				goto done;
			}
			k_tmp->rx_buf = rx_buf;
			rx_buf += len_aligned;
		}
		if (u_tmp->tx_buf) {
			/* this transfer needs space in TX bounce buffer */
			tx_total += len_aligned;
			if (tx_total > bufsiz) {
				status = -EMSGSIZE;
				goto done;
			}
			k_tmp->tx_buf = tx_buf;
			if (copy_from_user(tx_buf, (const u8 __user *)
						(uintptr_t) u_tmp->tx_buf,
					u_tmp->len))
				goto done;
			tx_buf += len_aligned;
		}

		k_tmp->cs_change = !!u_tmp->cs_change;
		k_tmp->tx_nbits = u_tmp->tx_nbits;
		k_tmp->rx_nbits = u_tmp->rx_nbits;
		k_tmp->bits_per_word = u_tmp->bits_per_word;
		k_tmp->delay_usecs = u_tmp->delay_usecs;
		k_tmp->speed_hz = u_tmp->speed_hz;
		k_tmp->word_delay_usecs = u_tmp->word_delay_usecs;
		if (!k_tmp->speed_hz)
			;//k_tmp->speed_hz = spidev->speed_hz;
#ifdef VERBOSE
		dev_dbg(&spidev->spi->dev,
			"  xfer len %u %s%s%s%dbits %u usec %u usec %uHz\n",
			u_tmp->len,
			u_tmp->rx_buf ? "rx " : "",
			u_tmp->tx_buf ? "tx " : "",
			u_tmp->cs_change ? "cs " : "",
			u_tmp->bits_per_word ? : spidev->spi->bits_per_word,
			u_tmp->delay_usecs,
			u_tmp->word_delay_usecs,
			u_tmp->speed_hz ? : spidev->spi->max_speed_hz);
#endif
		spi_message_add_tail(k_tmp, &spidev->m);
	}

	status = spidev_sync(spidev);
	if (status < 0)
		goto done;

	/* copy any rx data out of bounce buffer */
	for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
			n;
			n--, k_tmp++, u_tmp++) {
		if (u_tmp->rx_buf) {
			if (copy_to_user((u8 __user *)
					(uintptr_t) u_tmp->rx_buf, k_tmp->rx_buf,
					u_tmp->len)) {
				status = -EFAULT;
				goto done;
			}
		}
	}
	status = total;

done:
	kfree(k_xfers);
	return status;
}

static struct spi_ioc_transfer *
spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user *u_ioc,
		unsigned *n_ioc)
{
	u32	tmp;

	/* Check type, command number and direction */
	if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC
			|| _IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
			|| _IOC_DIR(cmd) != _IOC_WRITE)
		return ERR_PTR(-ENOTTY);

	tmp = _IOC_SIZE(cmd);
	if ((tmp % sizeof(struct spi_ioc_transfer)) != 0)
		return ERR_PTR(-EINVAL);
	*n_ioc = tmp / sizeof(struct spi_ioc_transfer);
	if (*n_ioc == 0)
		return NULL;

	/* copy into scratch area */
	return memdup_user(u_ioc, tmp);
}

static long
spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	struct spidev_data	*spidev;
	struct spi_device	*spi;
	u32			tmp;
	unsigned		n_ioc;
	struct spi_ioc_transfer	*ioc;
    int ret = 0;
    int result = 0;//信号量就绪
    unsigned long _info = 0;//arg change kernel value

    printk("fsfpgain:spidev_ioctl is run:0x%x-0x%x\r\n",cmd,arg);

	/* Check type and command number */
	// if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
    // {
    //     printk("spi is SPI_IOC_MAGIC\r\n");
	// 	return -ENOTTY;
    // }

	/* guard against device removal before, or while,
	 * we issue this ioctl.
	 */
	spidev = filp->private_data;
    printk("fsfpgain:spidev addr0x%x-%x;spi addr0x%x-%x\r\n",*spidev,spidev,*spidev->spi,spidev->spi);
	spin_lock_irq(&spidev->spi_lock);
	spi = spi_dev_get(spidev->spi);
	spin_unlock_irq(&spidev->spi_lock);

	if (spi == NULL)
    {
        printk("spi is null\r\n");
		return -ESHUTDOWN;
    }

	/* use the buffer lock here for triple duty:
	 *  - prevent I/O (from us) so calling spi_setup() is safe;
	 *  - prevent concurrent SPI_IOC_WR_* from morphing
	 *    data fields while SPI_IOC_RD_* reads them;
	 *  - SPI_IOC_MESSAGE needs the buffer locked "normally".
	 */
	mutex_lock(&spidev->buf_lock);

	switch (cmd) 
    {
		case 0x100:
			ret = 0x20000113;			
			break;
		case 0x309:
			spidev->b_workflag = 0;
			break;
		case 0x307:
			ret = DMAC_MAX_TRF_SIZE*DMA_RECV_MAX_NUM;
			break;
		case 0x306:
			ret = DMAC_MAX_TRF_SIZE;
			break;
		case 0x305:
			ret = spidev->send_data_len;
			break;
		case 0x304:
			ret = copy_from_user(&_info, &arg, sizeof(unsigned long));
			if (_info)
				spidev->b_printk = 1;
			else
				spidev->b_printk = 0;			
			break;
		case 0x303://开始工作由APP启动工作	
			spidev->read_buf_no = spidev->recv_buf_no;//重置可读数据块编号为最新接收到的数据块编号？		
			sema_init(&spidev->spi_sema,0);//初始化信号量
			spidev->b_workflag = 1;//开始工作标志
            printk("fafpgain start work!\r\n");
			ret = 1;
			break;
		case 0x302://设置spi传输数据大小并返回大小			
			ret = copy_from_user(&_info, &arg, sizeof(unsigned long));
			
			#ifdef _DEBUG
			printk("cmd 0x302 set len:%ld-%ld return :%d\r\n",_info,arg,ret);
			#endif
			spidev->send_data_len = arg;
			ret = spidev->send_data_len;
			if(DMAC_MAX_TRF_SIZE < arg)
			{//判断设置的一次接收fpga长度是否超出预设内存
				ret = -1;
				printk("iotcl cmd:%d arg:%ld error\r\n",cmd,_info);
				break;
			}
			init_p_buf_cut(spidev);
			break;
		case 0x301://应用程序获取一次buf，在此判断是否有buf
			#ifdef _DEBUG
			printk("test jiffies:%ld\r\n", jiffies);	
			#endif		
			result = down_timeout(&spidev->spi_sema,jiffies+msecs_to_jiffies(60));//获取信号
			#ifdef _DEBUG
			printk("down_temeout result:%d\r\n", result);	
			#endif
			spidev->copy_recv_buf_no = spidev->recv_buf_no;//copy一份当前值

			#ifdef _DEBUG
			printk("read_no:%d-copy_recv_no:%d\r\n",spidev->read_buf_no,spidev->copy_recv_buf_no);
			#endif
			if((spidev->read_buf_no != spidev->copy_recv_buf_no) && (0 == result))
			{//right
				if ((spidev->read_buf_no + 1) % DMA_RECV_MAX_NUM == spidev->copy_recv_buf_no)
				{
					ret = (spidev->read_buf_no | 0x10000);//不明白什么意思
				}else
				{
					ret = spidev->read_buf_no;
				}
				spidev->read_buf_no = NEXT_BUF(spidev->read_buf_no);				
			}
			else if (0 != result)
			{
				ret = -2;
			}
			else if (spidev->read_buf_no == spidev->copy_recv_buf_no)
			{
				ret = -3;
			}else
			{
				ret = -4;
			}
			#ifdef _DEBUG
			printk("0x301 ret:%d\r\n",ret);
			#endif
		    break;	
    }

	mutex_unlock(&spidev->buf_lock);	
	//#ifdef _DEBUGWZG
	printk("2121wzg cmd 0x%x  arg:%d  ret:%d  DMAC_MAX_TRF_SIZE:%d \r\n",cmd,arg,ret,DMAC_MAX_TRF_SIZE);
	//#endif
	spi_dev_put(spi);
	return ret;
}

#ifdef CONFIG_COMPAT
static long
spidev_compat_ioc_message(struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	struct spi_ioc_transfer __user	*u_ioc;
	int				retval = 0;
	struct spidev_data		*spidev;
	struct spi_device		*spi;
	unsigned			n_ioc, n;
	struct spi_ioc_transfer		*ioc;

	u_ioc = (struct spi_ioc_transfer __user *) compat_ptr(arg);

	/* guard against device removal before, or while,
	 * we issue this ioctl.
	 */
     printk("fsfpgain:spidev_compat_ioc_message\r\n");
	spidev = filp->private_data;
	spin_lock_irq(&spidev->spi_lock);
	spi = spi_dev_get(spidev->spi);
	spin_unlock_irq(&spidev->spi_lock);

	if (spi == NULL)
		return -ESHUTDOWN;

	/* SPI_IOC_MESSAGE needs the buffer locked "normally" */
	mutex_lock(&spidev->buf_lock);

	/* Check message and copy into scratch area */
	ioc = spidev_get_ioc_message(cmd, u_ioc, &n_ioc);
	if (IS_ERR(ioc)) {
		retval = PTR_ERR(ioc);
		goto done;
	}
	if (!ioc)
		goto done;	/* n_ioc is also 0 */

	/* Convert buffer pointers */
	for (n = 0; n < n_ioc; n++) {
		ioc[n].rx_buf = (uintptr_t) compat_ptr(ioc[n].rx_buf);
		ioc[n].tx_buf = (uintptr_t) compat_ptr(ioc[n].tx_buf);
	}

	/* translate to spi_message, execute */
	retval = spidev_message(spidev, ioc, n_ioc);
	kfree(ioc);

done:
	mutex_unlock(&spidev->buf_lock);
	spi_dev_put(spi);
	return retval;
}

static long
spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
    printk("fsfpgain:spidev_compat_ioctl\r\n");
	if (_IOC_TYPE(cmd) == SPI_IOC_MAGIC
			&& _IOC_NR(cmd) == _IOC_NR(SPI_IOC_MESSAGE(0))
			&& _IOC_DIR(cmd) == _IOC_WRITE)
		return spidev_compat_ioc_message(filp, cmd, arg);

	return spidev_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#else
#define spidev_compat_ioctl NULL
#endif /* CONFIG_COMPAT */

static int spidev_open(struct inode *inode, struct file *filp)
{
	struct spidev_data	*spidev;
	int			status = -ENXIO;

	mutex_lock(&device_list_lock);

	list_for_each_entry(spidev, &device_list, device_entry) {
		if (spidev->devt == inode->i_rdev) {
			status = 0;
			break;
		}
	}

	if (status) {
		pr_debug("spidev: nothing for minor %d\n", iminor(inode));
		goto err_find_dev;
	}

	spidev->users++;
	filp->private_data = spidev;
	stream_open(inode, filp);

	mutex_unlock(&device_list_lock);
	return 0;

err_alloc_rx_buf:
	kfree(spidev->tx_buffer);
	spidev->tx_buffer = NULL;
err_find_dev:
	mutex_unlock(&device_list_lock);
	return status;
}

static int spidev_release(struct inode *inode, struct file *filp)
{
	struct spidev_data	*spidev;
	int			dofree;

	mutex_lock(&device_list_lock);
	spidev = filp->private_data;
	filp->private_data = NULL;

	spin_lock_irq(&spidev->spi_lock);
	/* ... after we unbound from the underlying device? */
	dofree = (spidev->spi == NULL);
	spin_unlock_irq(&spidev->spi_lock);

	/* last close? */
	spidev->users--;
	if (!spidev->users) {

		//kfree(spidev->tx_buffer);
		spidev->tx_buffer = NULL;

		//kfree(spidev->rx_buffer);
		spidev->rx_buffer = NULL;

		if (dofree)
			kfree(spidev);
		else
			;//spidev->speed_hz = spidev->spi->max_speed_hz;
	}
#ifdef CONFIG_SPI_SLAVE
	if (!dofree)
		spi_slave_abort(spidev->spi);
#endif
	mutex_unlock(&device_list_lock);

	return 0;
}

static void init_p_buf_cut(struct spidev_data	*spidev)
{
	int i = 0;
	int j = 0;
	spidev->buf_cut->recv_num = spidev->send_data_len / DMAC_ONE_TR_NUM;
	spidev->buf_cut->last_buf_len = spidev->send_data_len % DMAC_ONE_TR_NUM;
	printk("buf_cut recv_num:%d last_buf_len:%d\r\n",spidev->buf_cut->recv_num,spidev->buf_cut->last_buf_len);

	for (i = 0; i < DMA_RECV_MAX_NUM; i++)
	{
		for (j = 0; j < DMAC_CNLL_MAX_NUM; j++)
		{
			spidev->buf_cut->pr_buf_fpga[i][j] = spidev->rxbuf.p_adr + (i*DMAC_MAX_TRF_SIZE) + (j*DMAC_ONE_TR_NUM);
		}
		printk("p_rx buf[%d] dma[%3d] padd:0x%x\r\n", i,j,spidev->buf_cut->pr_buf_fpga[i][0]);		
	}	
}

static int fsfpgain_mmap(struct file *filp, struct vm_area_struct *vma)
{
	int ret = 0;
    struct spidev_data *spidev;
    spidev = filp->private_data;
    printk("fsfpgain:spidev addr0x%x-%x;spi addr0x%x-%x\r\n",*spidev,spidev,*spidev->spi,spidev->spi);
	#ifdef _DEBUG
	printk("fsfpgain_mmap run,PAGE_SIZE:%ld\r\n",PAGE_SIZE);
	printk("vm_start:%lx vm_end:%lx\r\n", vma->vm_start,vma->vm_end);
	#endif
	//dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
	//      dma_addr_t dma_addr, size_t size, unsigned long attrs)
	ret =  dma_mmap_coherent(&spidev->spi->dev, vma, (void*)spidev->rxbuf.v_adr, spidev->rxbuf.p_adr,DMAC_MAX_TRF_SIZE*DMA_RECV_MAX_NUM);
			
	memset(spidev->rxbuf.v_adr, 0,DMAC_MAX_TRF_SIZE*DMA_RECV_MAX_NUM);

	#ifdef _DEBUG
	memcpy(spidev->rxbuf.v_adr, "Hello,mmap!", sizeof("Hello,mmap!"));//test mmap
	printk("fsfpgain_mmap re:%d-%s\r\n",ret,spidev->rxbuf.v_adr);
	#endif	
	memset(spidev->rxbuf.v_adr, 0,DMAC_MAX_TRF_SIZE*DMA_RECV_MAX_NUM);
	return ret;
}

static const struct file_operations spidev_fops = {
	.owner =	THIS_MODULE,
	/* REVISIT switch to aio primitives, so that userspace
	 * gets more complete API coverage.  It'll simplify things
	 * too, except for the locking.
	 */
	.write =	spidev_write,
	.read =		spidev_read,
	.unlocked_ioctl = spidev_ioctl,
	.compat_ioctl = spidev_compat_ioctl,
	.open =		spidev_open,
	.release =	spidev_release,
	.llseek =	no_llseek,
    .mmap = fsfpgain_mmap,
};

/*-------------------------------------------------------------------------*/

/* The main reason to have this class is to make mdev/udev create the
 * /dev/spidevB.C character device nodes exposing our userspace API.
 * It also simplifies memory management.
 */

static struct class *spidev_class;

#ifdef CONFIG_OF
static const struct of_device_id spidev_dt_ids[] = {
	{ .compatible = "fsml,fsfpgain" },
	{},
};
MODULE_DEVICE_TABLE(of, spidev_dt_ids);
#endif

#ifdef CONFIG_ACPI

/* Dummy SPI devices not to be used in production systems */
#define SPIDEV_ACPI_DUMMY	1

static const struct acpi_device_id spidev_acpi_ids[] = {
	/*
	 * The ACPI SPT000* devices are only meant for development and
	 * testing. Systems used in production should have a proper ACPI
	 * description of the connected peripheral and they should also use
	 * a proper driver instead of poking directly to the SPI bus.
	 */
	{ "SPT0001", SPIDEV_ACPI_DUMMY },
	{ "SPT0002", SPIDEV_ACPI_DUMMY },
	{ "SPT0003", SPIDEV_ACPI_DUMMY },
	{},
};
MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids);

static void spidev_probe_acpi(struct spi_device *spi)
{
	const struct acpi_device_id *id;

	if (!has_acpi_companion(&spi->dev))
		return;

	id = acpi_match_device(spidev_acpi_ids, &spi->dev);
	if (WARN_ON(!id))
		return;

	if (id->driver_data == SPIDEV_ACPI_DUMMY)
		dev_warn(&spi->dev, "do not use this driver in production systems!\n");
}
#else
static inline void spidev_probe_acpi(struct spi_device *spi) {}
#endif

/*-------------------------------------------------------------------------*/

static int spidev_probe(struct spi_device *spi)
{
	struct spidev_data	*spidev;
	int			status;
	unsigned long		minor;

	/*
	 * spidev should never be referenced in DT without a specific
	 * compatible string, it is a Linux implementation thing
	 * rather than a description of the hardware.
	 */
	WARN(spi->dev.of_node &&
	     of_device_is_compatible(spi->dev.of_node, "fsfpgain"),
	     "%pOF: buggy DT: spidev listed directly in DT\n", spi->dev.of_node);

	spidev_probe_acpi(spi);

	/* Allocate driver data */
	spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
	if (!spidev)
		return -ENOMEM;

	/* Initialize the driver data */
	spidev->spi = spi;
    printk("fsfpgain:spidev addr0x%x-%x;spi addr0x%x-%x\r\n",*spidev,spidev,*spi,spi);
	spin_lock_init(&spidev->spi_lock);
	mutex_init(&spidev->buf_lock);
    //sema_init(&spidev->spi_sema,0);//初始化信号量

	INIT_LIST_HEAD(&spidev->device_entry);

	/* If we can allocate a minor number, hook up this device.
	 * Reusing minors is fine so long as udev or mdev is working.
	 */
	mutex_lock(&device_list_lock);
	minor = find_first_zero_bit(minors, N_SPI_MINORS);
	if (minor < N_SPI_MINORS) {
		struct device *dev;

		spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
		dev = device_create(spidev_class, &spi->dev, spidev->devt,
				    spidev, "fsfpgain");
		status = PTR_ERR_OR_ZERO(dev);
	} else {
		dev_dbg(&spi->dev, "no minor number available!\n");
		status = -ENODEV;
	}
	if (status == 0) {
		set_bit(minor, minors);
		list_add(&spidev->device_entry, &device_list);
	}
	mutex_unlock(&device_list_lock);

	//spidev->speed_hz = spi->max_speed_hz;
    setSpidev_data(spidev);

	if (status == 0)
		spi_set_drvdata(spi, spidev);//spidev private reg
	else
		kfree(spidev);

	return status;
}

static int spidev_remove(struct spi_device *spi)
{
	struct spidev_data	*spidev = spi_get_drvdata(spi);

	/* prevent new opens */
	mutex_lock(&device_list_lock);
	/* make sure ops on existing fds can abort cleanly */
	spin_lock_irq(&spidev->spi_lock);
	spidev->spi = NULL;
	spin_unlock_irq(&spidev->spi_lock);

	list_del(&spidev->device_entry);
	device_destroy(spidev_class, spidev->devt);
	clear_bit(MINOR(spidev->devt), minors);

    resetSpidev_data(spidev);

	if (spidev->users == 0)
		kfree(spidev);
	mutex_unlock(&device_list_lock);

	return 0;
}

static struct spi_driver spidev_spi_driver = {
	.driver = {
		.name =		"fsfpgain",
		.of_match_table = of_match_ptr(spidev_dt_ids),
		.acpi_match_table = ACPI_PTR(spidev_acpi_ids),
	},
	.probe =	spidev_probe,
	.remove =	spidev_remove,

	/* NOTE:  suspend/resume methods are not necessary here.
	 * We don't do anything except pass the requests to/from
	 * the underlying controller.  The refrigerator handles
	 * most issues; the controller driver handles the rest.
	 */
};

/*-------------------------------------------------------------------------*/

static int __init spidev_init(void)
{
	int status;

	/* Claim our 256 reserved device numbers.  Then register a class
	 * that will key udev/mdev to add/remove /dev nodes.  Last, register
	 * the driver which manages those device numbers.
	 */
	BUILD_BUG_ON(N_SPI_MINORS > 256);
	status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops);
	if (status < 0)
		return status;

	spidev_class = class_create(THIS_MODULE, "fsfpgain");
	if (IS_ERR(spidev_class)) {
		unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name);
		return PTR_ERR(spidev_class);
	}

	status = spi_register_driver(&spidev_spi_driver);
	if (status < 0) {
		class_destroy(spidev_class);
		unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name);
	}
	return status;
}
module_init(spidev_init);

static void __exit spidev_exit(void)
{
	spi_unregister_driver(&spidev_spi_driver);
	class_destroy(spidev_class);
	unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name);
}
module_exit(spidev_exit);

MODULE_AUTHOR("shi guojie");
MODULE_DESCRIPTION("fsml");
MODULE_LICENSE("GPL");
MODULE_ALIAS("v1.0.0.0");

test_spidev.c

#include <stdio.h>
#include <ctype.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#define DEVICE_NAME "/dev/fsfpgain"
#define HEAD_LEN 5
#define PKT_MAX_LEN 0x40
#define STATUS_LEN 0x01

#define SUNXI_OP_WRITE 0x01
#define SUNXI_OP_READ 0x03

#define STATUS_WRITABLE 0x02
#define STATUS_READABLE 0x04

#define WRITE_DELAY 200
#define READ_DELAY 100000

void dump_data(unsigned char *buf, unsigned int len)
{
    unsigned int i;
    unsigned char tmp[len*2], cnt = 0;

    for (i = 0; i < len; i++) {
        if (i%0x10== 0)
            cnt += sprintf(tmp + cnt, "0x%08x: ", i);

        cnt += sprintf(tmp + cnt, "%02x ", buf[i]);

        if ( (i%0x10== 0x0f) || (i == (len -1)) ) {
            printf("%s\n", tmp);
            cnt = 0;
        }
    }
}

void batch_rand(char *buf, unsigned int length)
{
    unsigned int i;
    srand(time(0));

    for(i = 0; i < length; i++) {
        *(buf + i) = rand() % 256;
    }
}

int main(int argc, const char *argv[])
{
    unsigned int length = 0, test_len;
    char wbuf_head[HEAD_LEN] = {SUNXI_OP_WRITE, 0x0b, 0xb0, 0xea, 0x10};
    char rbuf_head[HEAD_LEN] = {SUNXI_OP_READ, 0x00, 0x00, 0xc0, 0x00};
    char wbuf[PKT_MAX_LEN], rbuf[PKT_MAX_LEN], i, time;
    int fd, ret;

    test_len = 10;//send 10 numbers
    if (test_len > PKT_MAX_LEN) {
        printf("invalid argument, numbers must less 64B\n");
        return -1;
    }

    wbuf_head[4] = test_len;
    rbuf_head[4] = test_len;

    for (i = 0; i < test_len; i++)
        wbuf[i] = i;
    printf("wbuf:\n");
    dump_data(wbuf, test_len);

    fd = open(DEVICE_NAME, O_RDWR);
    if (fd <= 0) {
        printf("Fail to to open %s\n", DEVICE_NAME);
        ret = -1;
        return ret;
    }
	char str[100];
	memset(str,0,100);
    int size = 1000;
    char* buffer = (char*)malloc(size * sizeof(char));
    
    char ch = 'a';
    for (int i = 0; i < size; i++) {
        buffer[i] = ch;
        ch++;
        if (ch > 'z') {
            ch = 'a';
        }
    }

    sprintf(str,"abcdefghijklmnabcdefghijklmnabcdefghijklmnabcdefghijklmnabcdefghijklmnabcdefghijklmnabcdefghijklmn");
//for(int x=0;x<10;x++)
    for(int x=0;x<10;x++)
    {
        write(fd, buffer, size);
    }
	
    if(0)
    {//write
        if (write(fd, wbuf_head, HEAD_LEN) != HEAD_LEN) {
            printf("W Fail to write head\n");
            ret = -1;
            goto err;
        } else
            printf("W write head successful\n");

        usleep(WRITE_DELAY);

        if (write(fd, wbuf, test_len) != test_len) {
            printf("W Fail to write data\n");
            ret = -1;
            goto err;
        } else
            printf("W write data successful\n");

        usleep(READ_DELAY);
    }

err:
    if (fd > 0)
        close(fd);

    return ret;
}

test_fsfpgain.c

#include <stdio.h>
#include <ctype.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <string.h>

#define DMAC_CNLL_MAX_NUM           32
#define DMAC_ONE_TR_NUM             1000
#define DMAC_MAX_TRF_SIZE           DMAC_CNLL_MAX_NUM*DMAC_ONE_TR_NUM
#define DMA_RECV_MAX_NUM            10//环形缓冲器大小

int main()
{
    int ret,fpdata,fpio,i,shmm_len,one_trf_len;
    long value;
    void* shmm_buf = NULL;
    char* trf_buf[DMAC_CNLL_MAX_NUM];
    char rbuf[1];
    char cstr[100] = "hello!spi world!";

    fpdata = open("/dev/fsfpgain", O_RDWR);
    if(0 > fpdata)
    {
        printf("open error!\r\n");
        return -1;
    }

    ret = ioctl(fpdata, 0x100, value);
    printf("100fsfpga version = 0x%x\r\n", ret);
    sleep(1);

    value = 10240;
    ret = ioctl(fpdata, 0x302, value);
    printf("302fsfpga set send-data-len = %d\r\n", ret);
    sleep(1);

    ret = ioctl(fpdata, 0x305, value);
    printf("0x305fsfpga get send-data-len = %d\r\n", ret);
    sleep(1);

    shmm_len = ioctl(fpdata, 0x307, value);
    printf("0x307shmm len = %d\r\n",shmm_len);
    sleep(1);

    one_trf_len = ioctl(fpdata, 0x306, value);
    printf("0x306one dmaspi len = %d\r\n",one_trf_len);
    sleep(1);

    printf("&shmm_buf:0x%p shmm_buf:0x%p shmm_len:%d\r\n",&shmm_buf, shmm_buf,shmm_len);
    shmm_buf = mmap(NULL, shmm_len, PROT_READ|PROT_WRITE,MAP_SHARED, fpdata,0);
    if(MAP_FAILED == shmm_buf)
    {
        printf("mmap error!\r\n");
        return 1;
    }
    printf("&shmm_buf:0x%p shmm_buf:0x%p shmm_len:%d\r\n",&shmm_buf, shmm_buf,shmm_len);

    printf("shmm_buf:%s\r\n",(char*)shmm_buf);
    sleep(1);

    ret = ioctl(fpdata, 0x303, value);
    printf("fsfpga start work = %d\r\n", ret);

    printf("sleep...\r\n");
    sleep(1);

    for(i = 0; i < DMA_RECV_MAX_NUM; i++)
    {
        trf_buf[i] = (char*)shmm_buf + (i * one_trf_len);
        printf("trf_buf[%d]add:0x%lx\r\n",i,(long)trf_buf[i]);
    }
    printf("trf_buf[0]:%s\r\n", trf_buf[0]);
    printf("set trf_buf ok\r\n");
    sleep(1);

    while (1)
    {
        //memset(shmm_buf, 0 ,shmm_len);
        ret = ioctl(fpdata, 0x301, value);
        printf("ioctl 0x301 ret:0x%x-v:0x%lx\r\n",ret, value);

        printf("get data no = %x\r\n",ret);
    
        value = 1;
        break;
        usleep(500*1000);
    }          
    
    printf("munmap return:%d\r\n",munmap(shmm_buf, shmm_len));
    close(fpdata);
    return 0;    
}

4.运行故障提示

# ./test_fafpgain
[ 4610.396357] fsfpgain:spidev_ioctl is run:0x100-0xb6ee3b58
[ 4610.402515] fsfpgain:spidev addr0x9900000-650065;spi addr0xc6594000-bf002018
[ 4610.410667] 2121wzg cmd 0x100  arg:-1225901224  ret:536871187  DMAC_MAX_TRF_SIZE:32000
100fsfpga version = 0x20000113
[ 4611.420340] fsfpgain:spidev_ioctl is run:0x302-0x2800
[ 4611.426075] fsfpgain:spidev addr0x9900000-660066;spi addr0xc6594000-bf002018
[ 4611.434057] buf_cut recv_num:10 last_buf_len:240
[ 4611.439322] p_rx buf[0] dma[ 32] padd:0x47880000
[ 4611.444561] p_rx buf[1] dma[ 32] padd:0x47887d00
[ 4611.449983] p_rx buf[2] dma[ 32] padd:0x4788fa00
[ 4611.455215] p_rx buf[3] dma[ 32] padd:0x47897700
[ 4611.460490] p_rx buf[4] dma[ 32] padd:0x4789f400
[ 4611.465722] p_rx buf[5] dma[ 32] padd:0x478a7100
[ 4611.470986] p_rx buf[6] dma[ 32] padd:0x478aee00
[ 4611.476223] p_rx buf[7] dma[ 32] padd:0x478b6b00
[ 4611.481478] p_rx buf[8] dma[ 32] padd:0x478be800
[ 4611.486730] p_rx buf[9] dma[ 32] padd:0x478c6500
[ 4611.491998] 2121wzg cmd 0x302  arg:10240  ret:10240  DMAC_MAX_TRF_SIZE:32000
302fsfpga set send-data-len = 10240
[ 4612.500269] fsfpgain:spidev_ioctl is run:0x305-0x2800
[ 4612.506000] fsfpgain:spidev addr0x9900000-670067;spi addr0xc6594000-bf002018
[ 4612.513984] 2121wzg cmd 0x305  arg:10240  ret:10240  DMAC_MAX_TRF_SIZE:32000
0x305fsfpga get send-data-len = 10240
[ 4613.522220] fsfpgain:spidev_ioctl is run:0x307-0x2800
[ 4613.528134] fsfpgain:spidev addr0x9900000-680068;spi addr0xc6594000-bf002018
[ 4613.536077] 2121wzg cmd 0x307  arg:10240  ret:320000  DMAC_MAX_TRF_SIZE:32000
0x307shmm len = 320000
[ 4614.544450] fsfpgain:spidev_ioctl is run:0x306-0x2800
[ 4614.550210] fsfpgain:spidev addr0x9900000-690069;spi addr0xc6594000-bf002018
[ 4614.558175] 2121wzg cmd 0x306  arg:10240  ret:32000  DMAC_MAX_TRF_SIZE:32000
0x306one dmaspi len = 32000
[ 4615.566559] fsfpgain:spidev addr0x9900000-6a006a;spi addr0xc6594000-bf002018

&shmm_buf:0x0xbe84bca4 shmm_buf:0x0xb6da9000 shmm_len:320000
shmm_buf:
[ 4616.579679] fsfpgain:spidev_ioctl is run:0x303-0x2800
[ 4616.585411] fsfpgain:spidev addr0x9900000-6a006a;spi addr0xc6594000-bf002018
[ 4616.593411] fafpgain start work!
[ 4616.597144] 2121wzg cmd 0x303  arg:10240  ret:1  DMAC_MAX_TRF_SIZE:32000
fsfpga start work = 1
sleep...
[ 4616.607572] fsfpgain:irq_gpio rec buf[0],add:47880000
[ 4616.613588] fafpgain:spi_fpga_recv 10-240
[ 4616.613593] fsfpgain:transfer len-1000 speed-10000000
[ 4616.623825] fsfpgain spi1.0: Bufferless transfer has length 1000
[ 4616.630553] fsfpgain: spidev_sync re-0
[ 4616.634722] fsfpgain: spidev_sync 10000000-0-1000
//fsfpgain spi1.0: Bufferless transfer has length 1000是spi.c中的报错，我没有理解为什么会跳到这里面来。使用test_spidev.c来测试，就不会跳进来，在驱动层面都是调用的write函数来读写的。

5.问题汇总：
1）通过GPIO中断来调用spi读写函数，spi不能正常工作，只有片选，没有时钟：

2）如何设置缓存，使得spi可以连续读取大数据量，目前片选频繁跳动，效率太低，25Hz的中断没办法完成数据读取。

YJ00871 LV 2

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