时间2013-10-13；

地点复旦大学第四教学楼；

网申职位：软件开发工程师

因自己准备不是很充分，这次百度笔试考得不好，当炮灰了，继续努力准备，加油！

1、 描述OSI（开放系统互联基本参考模型）七层结构。

2、 写出进程间数据共享的方式，至少三种。

3、 描述TCP和UDP的区别，并各写出一个他们的上层协议。

程序与算法设计

1、 给出数组A={a_0,a_1,a_2,...,a_n}（n是可变的），打印出所有元素的组合

2、 数组A中任意两个相邻元素大小相差1，现给定这样的数组A和目标整数t，找出t在数组A中的位置。

3、 求二叉树的面积（高乘宽），高为二叉树根到叶子节点的最大距离，宽慰二叉树最多的节点数。

系统设计题

给了一个百度地图的截图，对于地图上的某一点，需要在地图上标注该点的信息，将信息抽象成一个矩形，可以在该点的左边标记，也可以在该点右边标记。但是任意两点标记后的矩形是不能有覆盖的，否则删除其中一个点

问题1，现给一固定区域，有n个点，设计一个算法，要求标记足够多的点

AsyncTask

类的简介：

AsyncTask可以使UI线程更合理更简单的使用。这个类允许执行后台操作，而且可以在不使用多线程或handlers的情况下给主线程传输数据。

异步任务 被定义为在后台进行的运算，结果发布到主线程。

异步任务 被三种类型和四个步骤所定义，三种类型分别是Params，Progress，Result和四个步骤分别是begin，doInBackground，processProgress和end。

使用方法：

异步任务必须被继承使用，它的子类至少要覆写方法：doInBackground方法，通常也要覆写另一个方法：onPostExecute(Result)。

上面的代码是其子类异步下载文件的示例。

异步任务的三种类型

异步任务的三种类型的描述如下：

1.Params：发送给正在执行的任务的参数（参数类型）。

2.Progress：正在后台运算的时候发布的进度（进度类型）

3.Result：后台运算的结果（返回值的类型）

异步任务并不非得使用所有这些类型，为了标记不使用的类型，简单的在其位置上填入Void。

比如：上面的代码。

四个步骤：

当一个一步任务执行时，任务的四个步骤如下：

1.onPreExecute()，在异步执行时立即被UI线程调用，这一步通常用来设置任务，比如在用户界面显示进度条。

2.doInBackground(Params…)，当onPreExecute()方法执行完成时立即被后台线程调用。这一步用来执行耗时间的后台操作。异步任务的参数被传到这一步里。操作的结果必须在这一步被返回并且会被传到最后一步。这一步也可以使用publishProgress(Progress…)来发布一个或者多个进度单位。这些值在onProgressUpdate(Progress…)这一步被发布到UI进程中

3.onProgressUpdate(Progress…),在调用publishProgress(Progress…)之后被UI线程调用，执行的时间不定。这个方法用来在后台操作仍在执行的时候在用户界面显示不同形式的进度。比如它可以推动进度条进度或者在文本里显示log信息。

4.onPostExecute(Result…)，在后台程序结束后被UI线程调用。后台程序执行的结果以参数的形式传给这一步。

线程规则

为了是这一个类更好的被使用，要遵循下面几个原则：

1任务实例必须在主线程中创建

2Execute(Params…)必须被UI线程调用

3不用手动的调用onPreExecute(),onPostExecute(Result), dolnBackgrcund(Params. . .), onProgressUpdate(Progress.. .)

4任务只能被执行一次（当尝试执行第二个时会抛出异常）

spi通信不支持从设备主动给主设备发送数据，所以我把spi的用户空间驱动改了一下，实现过程是这样的，用一个中断来响应从设备的要求，即当STM32要主动给主设备发送数据的时候，将中断脚拉低，用户空间检测到中断后，主动给STM32发送一个空数据，这样spi就能读到STM32所要发送的数据了。SPI通信发数据与接数据是同时进行的，这个大家可以看下SPI协议。

以下我我修改的用户空间的驱动:

/*
 * spidev.c -- simple synchronous userspace interface to SPI devices
 *
 * Copyright (C) 2006 SWAPP
 *	Andrea Paterniani <a.paterniani@swapp-eng.it>
 * Copyright (C) 2007 David Brownell (simplification, cleanup)
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioctl.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/slab.h>

#include <linux/irq.h>
#include <linux/interrupt.h>
#include <mach/gpio.h>
#include <plat/gpio-cfg.h>
#include <mach/regs-gpio.h>
#include <linux/delay.h>

#include <linux/spi/spi.h>
#include <linux/spi/spidev_gzsd.h>

#include <asm/uaccess.h>

#include <linux/poll.h>

#define	SPI_IRQ			IRQ_EINT(2)
#define	IRQSTATE		S5PV210_GPH0(2)
#define BUF_SIZE		38
u8 gzsd_buffer[BUF_SIZE];
struct spi_transfer	*gk_xfers;
struct spi_ioc_transfer	*g_uxfers;
/*
 * This supports acccess 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)

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

	/* buffer is NULL unless this device is open (users > 0) */
	struct mutex		buf_lock;
	unsigned		users;
	u8			*buffer;
	int irq;
//add by dao
	wait_queue_head_t rqueue;
};

static flag_poll = 0;
static LIST_HEAD(device_list);
static DEFINE_MUTEX(device_list_lock);

static unsigned bufsiz = 4096;
module_param(bufsiz, uint, S_IRUGO);
MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");

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

/*
 * We can't use the standard synchronous wrappers for file I/O; we
 * need to protect against async removal of the underlying spi_device.
 */
static void spidev_complete(void *arg)
{
	complete(arg);
}

static ssize_t
spidev_sync(struct spidev_data *spidev, struct spi_message *message)
{
	DECLARE_COMPLETION_ONSTACK(done);
	int status;

	message->complete = spidev_complete;
	message->context = &done;
	spin_lock_irq(&spidev->spi_lock);
	if (spidev->spi == NULL)
		status = -ESHUTDOWN;
	else
		status = spi_async(spidev->spi, message);
	spin_unlock_irq(&spidev->spi_lock);

	if (status == 0) {
		wait_for_completion(&done);
		status = message->status;
		if (status == 0)
			status = message->actual_length;
	}
	return status;
}

static inline ssize_t
spidev_sync_write(struct spidev_data *spidev, size_t len)
{
	struct spi_transfer	t = {
			.tx_buf		= spidev->buffer,
			.len		= len,
		};
	struct spi_message	m;

	spi_message_init(&m);
	spi_message_add_tail(&t, &m);
	return spidev_sync(spidev, &m);
}

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

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

/* 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->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)
{
	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);
	missing = copy_from_user(spidev->buffer, buf, count);
	if (missing == 0) {
		status = spidev_sync_write(spidev, count);
	} else
		status = -EFAULT;
	mutex_unlock(&spidev->buf_lock);

	return status;
}

static int spidev_message(struct spidev_data *spidev,
		struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
{
	struct spi_message	msg;
	struct spi_transfer	*k_xfers;
	struct spi_transfer	*k_tmp;
	struct spi_ioc_transfer *u_tmp;
	unsigned		n, total;
	u8			*buf;
	int			status = -EFAULT;
	spi_message_init(&msg);
	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.
	 */
	buf = spidev->buffer;
	total = 0;
	for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
			n;
			n--, k_tmp++, u_tmp++) {
		k_tmp->len = u_tmp->len;
		total += k_tmp->len;
		if (total > bufsiz) {
			status = -EMSGSIZE;
			goto done;
		}
		if (u_tmp->rx_buf) {
			k_tmp->rx_buf = buf;
			if (!access_ok(VERIFY_WRITE, (u8 __user *)
						(uintptr_t) u_tmp->rx_buf,
						u_tmp->len))
				goto done;
		}
		if (u_tmp->tx_buf) {
			k_tmp->tx_buf = buf;
			if (copy_from_user(buf, (const u8 __user *)
						(uintptr_t) u_tmp->tx_buf,
					u_tmp->len))
				goto done;
		}

		buf += k_tmp->len;

		k_tmp->cs_change = !!u_tmp->cs_change;
		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;
#ifdef VERBOSE
		dev_dbg(&spidev->spi->dev,
			"  xfer len %zd %s%s%s%dbits %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->speed_hz ? : spidev->spi->max_speed_hz);
#endif
		spi_message_add_tail(k_tmp, &msg);
	}
	printk("%s :----line is %d\n",__func__,__LINE__);
	status = spidev_sync(spidev, &msg);
	printk("%s :----line is %d\n",__func__,__LINE__);
	if (status < 0)
		goto done;
	/* copy any rx data out of bounce buffer */
	buf = spidev->buffer;
	for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
		if (u_tmp->rx_buf) {
			if (__copy_to_user((u8 __user *)
					(uintptr_t) u_tmp->rx_buf, buf,
					u_tmp->len)) {
				status = -EFAULT;
				goto done;
			}
		}
		buf += u_tmp->len;
	}
	status = total;

done:
	kfree(k_xfers);
	return status;
}

static DECLARE_WAIT_QUEUE_HEAD(gzsd_spi_wait);

static irqreturn_t gzsd_spiread(int irq, void *dev_id)
{
	struct spidev_data *spidev = (struct spidev_data *)dev_id;

	//dev_err(&spidev->spi->dev, "is spi dev now.\n");
	disable_irq_nosync(irq);
	flag_poll = 1;
	//printk("%s:------------line is %d\n",__func__,__LINE__);
#if	1
	wake_up_interruptible(&spidev->rqueue);
#else
	wake_up(&gzsd_spi_wait);
#endif
	//wake_up_interruptible_sync(&spidev->rqueue);
	//wake_up(&spidev->rqueue);
	enable_irq(irq);
	return IRQ_HANDLED;
}

unsigned int gzsd_poll(struct file *filp, poll_table *wait)
{
	struct spidev_data	*spidev;
	spidev = filp->private_data;
	unsigned int mask = 0;
	//printk("%s:------------line is %d\n",__func__,__LINE__);
#if	1
	poll_wait(filp, &spidev->rqueue, wait);
#else
	poll_wait(filp, &gzsd_spi_wait, wait);
#endif
	if(flag_poll) {
		mask = POLLIN | POLLRDNORM; //can be read
		flag_poll = 0;
	}
	return mask;
}

static long
spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	int			err = 0;
	int			retval = 0;
	struct spidev_data	*spidev;
	struct spi_device	*spi;
	u32			tmp;
	unsigned		n_ioc;
	struct spi_ioc_transfer	*ioc;

	/* Check type and command number */
	if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
		return -ENOTTY;

	/* Check access direction once here; don't repeat below.
	 * IOC_DIR is from the user perspective, while access_ok is
	 * from the kernel perspective; so they look reversed.
	 */
	if (_IOC_DIR(cmd) & _IOC_READ)
		err = !access_ok(VERIFY_WRITE,
				(void __user *)arg, _IOC_SIZE(cmd));
	if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE)
		err = !access_ok(VERIFY_READ,
				(void __user *)arg, _IOC_SIZE(cmd));
	if (err)
		return -EFAULT;

	/* guard against device removal before, or while,
	 * we issue this ioctl.
	 */
	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;

	/* 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) {
	/* read requests */
	case SPI_IOC_RD_MODE:
		retval = __put_user(spi->mode & SPI_MODE_MASK,
					(__u8 __user *)arg);
		break;
	case SPI_IOC_RD_LSB_FIRST:
		retval = __put_user((spi->mode & SPI_LSB_FIRST) ?  1 : 0,
					(__u8 __user *)arg);
		break;
	case SPI_IOC_RD_BITS_PER_WORD:
		retval = __put_user(spi->bits_per_word, (__u8 __user *)arg);
		break;
	case SPI_IOC_RD_MAX_SPEED_HZ:
		retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg);
		break;

	/* write requests */
	case SPI_IOC_WR_MODE:
		retval = __get_user(tmp, (u8 __user *)arg);
		if (retval == 0) {
			u8	save = spi->mode;

			if (tmp & ~SPI_MODE_MASK) {
				retval = -EINVAL;
				break;
			}

			tmp |= spi->mode & ~SPI_MODE_MASK;
			spi->mode = (u8)tmp;
			retval = spi_setup(spi);
			if (retval < 0)
				spi->mode = save;
			else
				dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
		}
		break;
	case SPI_IOC_WR_LSB_FIRST:
		retval = __get_user(tmp, (__u8 __user *)arg);
		if (retval == 0) {
			u8	save = spi->mode;

			if (tmp)
				spi->mode |= SPI_LSB_FIRST;
			else
				spi->mode &= ~SPI_LSB_FIRST;
			retval = spi_setup(spi);
			if (retval < 0)
				spi->mode = save;
			else
				dev_dbg(&spi->dev, "%csb first\n",
						tmp ? 'l' : 'm');
		}
		break;
	case SPI_IOC_WR_BITS_PER_WORD:
		retval = __get_user(tmp, (__u8 __user *)arg);
		if (retval == 0) {
			u8	save = spi->bits_per_word;

			spi->bits_per_word = tmp;
			retval = spi_setup(spi);
			if (retval < 0)
				spi->bits_per_word = save;
			else
				dev_dbg(&spi->dev, "%d bits per word\n", tmp);
		}
		break;
	case SPI_IOC_WR_MAX_SPEED_HZ:
		retval = __get_user(tmp, (__u32 __user *)arg);
		if (retval == 0) {
			u32	save = spi->max_speed_hz;

			spi->max_speed_hz = tmp;
			retval = spi_setup(spi);
			if (retval < 0)
				spi->max_speed_hz = save;
			else
				dev_dbg(&spi->dev, "%d Hz (max)\n", tmp);
		}
		break;

	default:
		/* segmented and/or full-duplex I/O request */
		if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
				|| _IOC_DIR(cmd) != _IOC_WRITE) {
			retval = -ENOTTY;
			break;
		}

		tmp = _IOC_SIZE(cmd);
		if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) {
			retval = -EINVAL;
			break;
		}

		n_ioc = tmp / sizeof(struct spi_ioc_transfer);

		if (n_ioc == 0)
			break;

		g_uxfers = kmalloc(tmp, GFP_KERNEL);
		if (!g_uxfers) {
			printk("g_uxfers alloc failed\n");
		}
		if (__copy_from_user(g_uxfers, (void __user *)arg, tmp)) {
			kfree(g_uxfers);
			printk("g_uxfers copy failed\n");
		}

		/* copy into scratch area */
		ioc = kmalloc(tmp, GFP_KERNEL);
		if (!ioc) {
			retval = -ENOMEM;
			break;
		}

		if (__copy_from_user(ioc, (void __user *)arg, tmp)) {
			kfree(ioc);
			retval = -EFAULT;
			break;
		}

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

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

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

	mutex_lock(&device_list_lock);
	
	gk_xfers = kcalloc(1, sizeof (*gk_xfers), GFP_KERNEL);
	if (gk_xfers == NULL)
		printk("alloc gk_xfers_failed\n");

	list_for_each_entry(spidev, &device_list, device_entry) {
		if (spidev->devt == inode->i_rdev) {
			status = 0;
			break;
		}
	}
	if (status == 0) {
		if (!spidev->buffer) {
			spidev->buffer = kmalloc(bufsiz, GFP_KERNEL);
			if (!spidev->buffer) {
				dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
				status = -ENOMEM;
			}
		}
		if (status == 0) {
			spidev->users++;
			filp->private_data = spidev;
			nonseekable_open(inode, filp);
		}
	} else
		pr_debug("spidev: nothing for minor %d\n", iminor(inode));
	mutex_unlock(&device_list_lock);
	return status;
}

static int spidev_release(struct inode *inode, struct file *filp)
{
	struct spidev_data	*spidev;
	int			status = 0;

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

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

		kfree(spidev->buffer);
		spidev->buffer = NULL;

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

		if (dofree)
			kfree(spidev);
	}
	//disable_irq_nosync(spidev->irq);
	kfree(gk_xfers);
	kfree(g_uxfers);
	mutex_unlock(&device_list_lock);

	return status;
}

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,
	.open =		spidev_open,
	.release =	spidev_release,
	.poll		=gzsd_poll,
};

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

/* 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;

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

static int __devinit spidev_probe(struct spi_device *spi)
{
	struct spidev_data	*spidev;
	int			status;
	unsigned long		minor;
	int err;
	/* Allocate driver data */
	spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
	if (!spidev)
		return -ENOMEM;

	/* Initialize the driver data */
	spidev->spi = spi;
	spin_lock_init(&spidev->spi_lock);
	mutex_init(&spidev->buf_lock);

	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, "spidev%d.%d",
				    spi->master->bus_num, spi->chip_select);
		status = IS_ERR(dev) ? PTR_ERR(dev) : 0;
	} 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);
	}

	spidev->irq = SPI_IRQ;

	err = request_irq(spidev->irq, gzsd_spiread, IRQ_TYPE_EDGE_FALLING,"spi", spidev);
	if(err < 0) {
		dev_err(&spidev->spi->dev, "Unable to request spi IRQ.\n");
	}

	init_waitqueue_head(&spidev->rqueue);

	mutex_unlock(&device_list_lock);

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

	return status;
}

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

	/* make sure ops on existing fds can abort cleanly */
	spin_lock_irq(&spidev->spi_lock);
	spidev->spi = NULL;
	spi_set_drvdata(spi, NULL);
	spin_unlock_irq(&spidev->spi_lock);

	/* prevent new opens */
	mutex_lock(&device_list_lock);
	list_del(&spidev->device_entry);
	device_destroy(spidev_class, spidev->devt);
	clear_bit(MINOR(spidev->devt), minors);
	if (spidev->users == 0)
		kfree(spidev);
	mutex_unlock(&device_list_lock);

	return 0;
}

static struct spi_driver spidev_spi_driver = {
	.driver = {
		.name =		"spidev",
		.owner =	THIS_MODULE,
	},
	.probe =	spidev_probe,
	.remove =	__devexit_p(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, "spidev");
	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("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
MODULE_DESCRIPTION("User mode SPI device interface");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:spidev");

位置: drivers/spi

将drivers/spi/Makefile里的spidev.c修改为spidev_gzsd.c

210　spi测试程序如下:

/*
 * SPI testing utility (using spidev driver)
 *
 * Copyright (c) 2007  MontaVista Software, Inc.
 * Copyright (c) 2007  Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * 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.
 *
 * Cross-compile with cross-gcc -I/path/to/cross-kernel/include
 */

#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include "spidev.h"
//#include <termios.h>

#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))

#define BUF_SIZE	38
#define READ_SIZE	(BUF_SIZE + 1)

static const char *device = "/dev/spidev0.0";
static uint8_t mode;
static uint8_t bits = 8;
static uint32_t speed = 140000;//140000;
static uint16_t delay;

static void transfer(int fd)
{
	int ret;

	uint8_t tx[] = {
		0x01, 0xFD, 0xFC, 0xFB, 0xFA, 0xF9,
		0xF8, 0xF7, 0xF6, 0xF5, 0xF4, 0xF3,
		0xF2, 0xF1, 0xF0, 0xEF, 0xEE, 0xED,
		0xEC, 0xEB, 0xEA, 0xE9, 0xE8, 0xE7,
		0xE6, 0xE5, 0xE4, 0xE3, 0xE2, 0xE1,
		0xE0, 0xDF, 0xDE, 0xDD, 0xDC, 0xDB,
		0xDA, 0xD9,
	};

	uint8_t rx[ARRAY_SIZE(tx)] = {0, };
	struct spi_ioc_transfer tr = {
		.tx_buf = (unsigned long)tx,
		.rx_buf = (unsigned long)rx,
		.len = ARRAY_SIZE(tx),
		.delay_usecs = delay,
		.speed_hz = speed,
		.bits_per_word = bits,
	};
	ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
#if	1
	if(rx[0] != 0xff)
	{
		for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
			if (!(ret % 6))
				puts("");
			printf("%.2d ", rx[ret]);
		}
		puts("");
	}
#endif
}

static void do_read(int fd, int len)
{
	uint8_t	buf[len], bp[len];
	int		status;

	/* read at least 2 bytes, no more than 32 */
	if (len < 2)
		len = 2;
	else if (len > sizeof(buf))
		len = sizeof(buf);
	memset(buf, 0, sizeof buf);

	status = read(fd, buf, len);
	if (status < 0) {
		printf("read error \n");
		return;
	}
	if (status != len) {
		fprintf(stderr, "short read\n");
		return;
	}
#if	0
	printf("read(%2d, %2d): %02x %02x,", len, status,
		buf[0], buf[1]);
	status -= 2;
	bp = buf + 2;
	while (status-- > 0)
		printf(" %02x", *bp++);
	printf("\n");
#else
	int i;
#if	1
	printf("do read data is :\n");
	for(i = 0;i < len;i++)
		printf("  %d",buf[i]);
	printf("\n");
#else
	for(i = 0;i < (len - 1);i++)
	{
		bp[i] = buf[i+1];
	}
	bp[len-1] = buf[0];
	printf("data is :\n");
	for(i = 0;i < len;i++)
		printf("  %d",bp[i]);
	printf("\n");
#endif
#endif
}

static void do_write(int fd,int cmd)
{
	struct spi_ioc_transfer	xfer;
	//unsigned char		buf[BUF_SIZE], *bp;
	uint8_t			buf[BUF_SIZE], *bp;
	int			status;
	int			len;

	uint8_t tx[] = {
		cmd, (cmd +1), (cmd+2), 0xFB, 0xFA, 0xF9,
		0xF8, 0xF7, 0xF6, 0xF5, 0xF4, 0xF3,
		0xF2, 0xF1, 0xF0, 0xEF, 0xEE, 0xED,
		0xEC, 0xEB, 0xEA, 0xE9, 0xE8, 0xE7,
		0xE6, 0xE5, 0xE4, 0xE3, 0xE2, 0xE1,
		0xE0, 0xDF, 0xDE, 0xDD, 0xDC, 0xDB,
		0xDA, 0xD9,
	};
	//memset(xfer, 0, sizeof xfer);
	memset(buf, 1, sizeof buf);

	len = sizeof buf;
	//buf[0] = cmd;
#if	0
	buf[0] = cmd;
	buf[1] = cmd;

	xfer.tx_buf = (unsigned long)buf;
	xfer.len = len;

	status = ioctl(fd, SPI_IOC_MESSAGE(1), xfer);
	if (status < 0) {
		printf("SPI_IOC_MESSAGE\n");
		return;
	}
	//printf("do write data is %d\n",buf[0]);
	printf("response(%2d, %2d)\n", len, status);
#endif
	status = write(fd,tx,BUF_SIZE);
	if(status < 0)
		printf("do write failed\n");
#if	0
	for (bp = buf; len; len--)
		printf(" %02x", *bp++);
	printf("\n");
#endif

}

int main(int argc, char *argv[])
{
	int ret = 0;
	int fd;
	int data;
	fd_set rds;    
	struct timeval tv;
#if	0
	if(argc < 2) {
		printf("please enter one parameter at least\n");
		return 0;
	}

	data = atoi(argv[1]);
#else
	data = 0;
#endif
	fd = open(device, O_RDWR);
	if (fd < 0)
		printf("can't open device");

	mode = SPI_MODE_1;
	/*
	 * spi mode
	 */
	ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
	if (ret == -1)
		printf("can't set spi mode");

	ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
	if (ret == -1)
		printf("can't get spi mode");

	/*
	 * bits per word
	 */
	ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
	if (ret == -1)
		printf("can't set bits per word");

	ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
	if (ret == -1)
		printf("can't get bits per word");

	/*
	 * max speed hz
	 */
	ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
	if (ret == -1)
		printf("can't set max speed hz");

	ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
	if (ret == -1)
		printf("can't get max speed hz");

	printf("spi mode: %d\n", mode);
	printf("bits per word: %d\n", bits);
	printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);

	//FD_ZERO(&rds);    
	//FD_SET(fd, &rds);
	//tv.tv_sec = 10;
	//tv.tv_usec = 0;
	int i;
	while(1)
	{
		
		FD_ZERO(&rds);    
		FD_SET(fd, &rds);
		tv.tv_sec = 1;
		tv.tv_usec = 0;
		printf("send daia is -----------------------%d\n",data);
		do_write(fd,data);
		sleep(1);	
		ret = select(fd+1,&rds,NULL,NULL,&tv);
		if(ret < 0) {
			printf("select error!\n");
			//break;
		}
		printf("ret is +++++++++++++++++++%d\n",ret);
		if (FD_ISSET(fd, &rds))
			do_read(fd,BUF_SIZE);
		data++;
		if(data > 8)
			data = 0;
		sleep(1);
	}
	close(fd);

	return ret;
}

STM32主函数代码:

#include "stm32f10x.h"
#include "uart.h"
#include "spi.h"


void SPItest(void);
void UARTtest(USART_TypeDef *port);
extern void Uart_SendStringn(USART_TypeDef *port,char *pt,int n);
extern  void Delay_ARMJISHU(__IO uint32_t nCount);

void SPIsend_Init(void)
{
	GPIO_InitTypeDef  GPIO_InitStructure;
//spi send interrupt control
	RCC_APB2PeriphClockCmd (RCC_APB2Periph_GPIOC, ENABLE);//	使能PC,AFIO
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; 
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 
	//GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //推挽输出 
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //
	GPIO_Init(GPIOC, &GPIO_InitStructure); 
//end
}
void send_onoff(int onoff)
{
	if(onoff)
		GPIO_WriteBit(GPIOC, GPIO_Pin_7, Bit_RESET);
	else
		GPIO_WriteBit(GPIOC, GPIO_Pin_7, Bit_SET);
}

int main(void)
{

  //int i;

	NVIC_Configuration();//配置  NVIC 和 Vector Table 
   
	Uart1_COMInit(115200); //串口1连接v210或PC机

 	SPI1_Init();
	SPIsend_Init();  
	send_onoff(Bit_RESET);

	Uart_SendString(USART1,"串口1开始：\r\n") ;	//串口1接PC机


	while (1)
	{
		 SPItest();
	}
   
}

void send_data(int mode)
{
	int i;
	send_onoff(Bit_SET);
	switch(mode)
	{
		case 0x01:
			for(i=0;i<38;i++)
			{
				SPI_I2S_SendData(SPI1,i + 1);
			}
			break;
		case 0x02:
			for(i=0;i<38;i++)
			{
				SPI_I2S_SendData(SPI1,i + 2);
			}
			break;

		case 0x03:
			for(i=0;i<38;i++)
			{
				SPI_I2S_SendData(SPI1,i + 3);
			}
			break;
		default:
			break;
	}
	send_onoff(Bit_RESET);
	cmd = 0;
	return;
}

void SPItest(void)
{
	int i;
	//static int	x=0;

	if(RxIdx==SPI_BufferSize) //中断方式接收
	{
		cmd = SPI1_Buffer_Rx[0];
		for(i=0;i< RxIdx;i++)
		{
			Uart_SendByte(USART1,SPI1_Buffer_Rx[i]);//向PC机发送
			// SPI_I2S_SendData(SPI1,0xff); 
		 	SPI1_Buffer_Rx[i]=0;
		}
		//while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
		//SPI_I2S_SendData(SPI1,x++);
		//send_onoff(1);
		//SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_RXNE, ENABLE);
		//Delay_ARMJISHU(10000000);
		RxIdx=0;
		SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_RXNE, ENABLE);
	}

	if(cmd)
	send_data(cmd);
 //查询方式接收：
/*
	while (SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_RXNE) == RESET);
    SPI3_Buffer_Rx[RxIdx++] = SPI_I2S_ReceiveData(SPI3);
	if(RxIdx==SPI_BufferSize)
	{
		for(i=0;i< RxIdx;i++)
		{
	  	Uart_SendByte(USART1,SPI3_Buffer_Rx[i]);//向PC机发送

		}
		RxIdx=0;
	}
*/
}

void UARTtest(USART_TypeDef *port)
{
int i;
	
	for(i=0;i<10;i++)
		Uart_SendByte(port,'0'+i);
	Delay_ARMJISHU(10000000);

}