기존 이솝 임베디드 포럼의 지식인 서비스가 게시판 형태로 변경되었습니다.
글 수 6,368
spidev_probe() 함수에 printk() 로 내용을 찍어보아도,, 부팅시 나오지가 않네요..
spidev_init() 함수에 찍었을때는 잘 나오더군요..
제공된 소스 그대로인데,, 수정을 가해야 할까요...??
/*
* spidev.c -- simple synchronous userspace interface to SPI devices
*
* Copyright (C) 2006 SWAPP
* Andrea Paterniani <[email protected]>
* 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/spi/spi.h>
#include <linux/spi/spidev.h> #include <asm/uaccess.h>
/*
* 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;
}; 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 %uHzn",
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);
} status = spidev_sync(spidev, &msg);
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 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 %02xn", 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 firstn",
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 wordn", 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; /* 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); 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/ENOMEMn");
status = -ENOMEM;
}
}
if (status == 0) {
spidev->users++;
filp->private_data = spidev;
nonseekable_open(inode, filp);
}
} else
pr_debug("spidev: nothing for minor %dn", 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);
}
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,
}; /*-------------------------------------------------------------------------*/ /* 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; /* 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);
}
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, <[email protected]>");
MODULE_DESCRIPTION("User mode SPI device interface");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:spidev");
* spidev.c -- simple synchronous userspace interface to SPI devices
*
* Copyright (C) 2006 SWAPP
* Andrea Paterniani <[email protected]>
* 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/spi/spi.h>
#include <linux/spi/spidev.h> #include <asm/uaccess.h>
/*
* 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;
}; 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 %uHzn",
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);
} status = spidev_sync(spidev, &msg);
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 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 %02xn", 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 firstn",
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 wordn", 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; /* 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); 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/ENOMEMn");
status = -ENOMEM;
}
}
if (status == 0) {
spidev->users++;
filp->private_data = spidev;
nonseekable_open(inode, filp);
}
} else
pr_debug("spidev: nothing for minor %dn", 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);
}
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,
}; /*-------------------------------------------------------------------------*/ /* 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; /* 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);
}
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, <[email protected]>");
MODULE_DESCRIPTION("User mode SPI device interface");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:spidev");
여러차례 SPI 관련하여 질문을 올리신 것으로 알고 있습니다.
매번 내용을 보았습니다만 문제 해결의 출발이 잘못된 것으로 판단됩니다.
삼성에서 SMDK6410 용으로 배포한 커널이나 aesop6410 용으로 배포한 커널에서도 SPI 사용에는 아무 문제가 없습니다.
기본으로한 커널이 어떤 버전이며 어디서 배포한 것인지 확인하시는 것이 선행되어야 할 것이라고 생각됩니다.
aesop6410에 SPI을 활성화 했을 때 나타나는 메시지입니다.
CHK include/linux/compile.h
CC arch/arm/mach-s3c6410/mach-smdk6410.o
LD arch/arm/mach-s3c6410/built-in.o
CC drivers/spi/spi.o
CC drivers/spi/spi-dev.o
CC drivers/spi/hspi-s3c64xx.o
LD drivers/spi/built-in.o
LD drivers/built-in.o
LD vmlinux.o
MODPOST vmlinux.o
GEN .version
CHK include/linux/compile.h
UPD include/linux/compile.h
CC init/version.o
LD init/built-in.o
LD .tmp_vmlinux1
KSYM .tmp_kallsyms1.S
AS .tmp_kallsyms1.o
LD .tmp_vmlinux2
KSYM .tmp_kallsyms2.S
AS .tmp_kallsyms2.o
LD vmlinux
SYSMAP System.map
SYSMAP .tmp_System.map
OBJCOPY arch/arm/boot/Image
Kernel: arch/arm/boot/Image is ready
GZIP arch/arm/boot/compressed/piggy.gz
AS arch/arm/boot/compressed/piggy.o
LD arch/arm/boot/compressed/vmlinux
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
또한 한가지 더 확인하셔야 할 내용은 GPIO 설정에 대한 것입니다. 6410의 경우 GPC 가 SPI로 사용할 수 있도록 되어 있는데 각 포트가 다른 것으로 할 당되어 있는지 확인해 보세요 다른 기능으로 설정되어 있으면 SPI driver가 등록이 되어도 동작을 하지 않습니다. 일단 등록이 되었다면 kernel root의 Documentation/spi에 들어가 보시면 Test 할 수 있는 sample 프로그램이 있습니다. 이 source를 참고하시면 동작도 Test 해 보실 수 있습니다.
CC arch/arm/mach-s3c6410/mach-smdk6410.o
LD arch/arm/mach-s3c6410/built-in.o
CC drivers/spi/spi.o
CC drivers/spi/spi-dev.o
CC drivers/spi/hspi-s3c64xx.o
LD drivers/spi/built-in.o
LD drivers/built-in.o
LD vmlinux.o
MODPOST vmlinux.o
GEN .version
CHK include/linux/compile.h
UPD include/linux/compile.h
CC init/version.o
LD init/built-in.o
LD .tmp_vmlinux1
KSYM .tmp_kallsyms1.S
AS .tmp_kallsyms1.o
LD .tmp_vmlinux2
KSYM .tmp_kallsyms2.S
AS .tmp_kallsyms2.o
LD vmlinux
SYSMAP System.map
SYSMAP .tmp_System.map
OBJCOPY arch/arm/boot/Image
Kernel: arch/arm/boot/Image is ready
GZIP arch/arm/boot/compressed/piggy.gz
AS arch/arm/boot/compressed/piggy.o
LD arch/arm/boot/compressed/vmlinux
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
또한 한가지 더 확인하셔야 할 내용은 GPIO 설정에 대한 것입니다. 6410의 경우 GPC 가 SPI로 사용할 수 있도록 되어 있는데 각 포트가 다른 것으로 할 당되어 있는지 확인해 보세요 다른 기능으로 설정되어 있으면 SPI driver가 등록이 되어도 동작을 하지 않습니다. 일단 등록이 되었다면 kernel root의 Documentation/spi에 들어가 보시면 Test 할 수 있는 sample 프로그램이 있습니다. 이 source를 참고하시면 동작도 Test 해 보실 수 있습니다.
아래는 갤럭시S2 소스지만 등록하는 방법은 같습니다.(https://github.com/GalaxySII/samsung-kernel-galaxysii.git)
$ grep -R "name" drivers/spi/spidev.c
.name = "spidev",
이진파일 drivers/spi/spidev.o 와(과) 일치
$ grep -R "spidev" arch/arm/mach-s*
arch/arm/mach-s5p6450/mach-smdk6450.c: .modalias = "spidev", /* MMC SPI */
arch/arm/mach-s5p6450/mach-smdk6450.c: .modalias = "spidev", /* MMC SPI */
arch/arm/mach-s5pv210/mach-smdkv210.c: .modalias = "spidev", /* MMC SPI */
arch/arm/mach-s5pv210/mach-smdkv210.c: .modalias = "spidev", /* MMC SPI */
arch/arm/mach-s5pv310/mach-smdkc210.c: .modalias = "spidev",
arch/arm/mach-s5pv310/mach-smdkc210.c: .modalias = "spidev",
arch/arm/mach-s5pv310/mach-smdkc210.c: .modalias = "spidev",
arch/arm/mach-s5pv310/mach-smdkv310.c: .modalias = "spidev",
arch/arm/mach-s5pv310/mach-smdkv310.c: .modalias = "spidev",
arch/arm/mach-s5pv310/mach-smdkv310.c: .modalias = "spidev",
arch/arm/mach-s5pv310/mach-c1.c: .modalias = "spidev",
$ vi arch/arm/mach-s5pv310/mach-c1.c- 391 static struct spi_board_info spi0_board_info[] __initdata = {
| 412 #else
|- 413 {
|| 414 .modalias = "spidev",
|| 415 .platform_data = NULL,
|| 416 .max_speed_hz = 10*1000*1000,
|| 417 .bus_num = 0,
|| 418 .chip_select = 0,
|| 419 .mode = SPI_MODE_0,
|| 420 .controller_data = &spi0_csi[0],
|| 421 }
| 422 #endif
| 6327 spi_register_board_info(spi0_board_info, ARRAY_SIZE(spi0_board_info));