diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/spi/spidev.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/spi/spidev.c | 701 |
1 files changed, 0 insertions, 701 deletions
diff --git a/ANDROID_3.4.5/drivers/spi/spidev.c b/ANDROID_3.4.5/drivers/spi/spidev.c deleted file mode 100644 index 830adbed..00000000 --- a/ANDROID_3.4.5/drivers/spi/spidev.c +++ /dev/null @@ -1,701 +0,0 @@ -/* - * 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/compat.h> - -#include <linux/spi/spi.h> -#include <linux/spi/spidev.h> - -#include <asm/uaccess.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) - -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 %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); - } - - 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 %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; - - /* 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; -} - -#ifdef CONFIG_COMPAT -static long -spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long 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 == 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); - } - 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, - .compat_ioctl = spidev_compat_ioctl, - .open = spidev_open, - .release = spidev_release, - .llseek = no_llseek, -}; - -/*-------------------------------------------------------------------------*/ - -/* 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, <a.paterniani@swapp-eng.it>"); -MODULE_DESCRIPTION("User mode SPI device interface"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("spi:spidev"); |