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![Dan Carpenter](/assets/img/avatar_default.png)
This unlocks twice due to a merge issue.
Fixes: 35bba23e67
("Merge remote-tracking branch 'spi/for-6.2' into spi-6.2")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y+ETCk7XKfAy8yWQ@kili
Signed-off-by: Mark Brown <broonie@kernel.org>
906 lines
23 KiB
C
906 lines
23 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Simple synchronous userspace interface to SPI devices
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*
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* Copyright (C) 2006 SWAPP
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* Andrea Paterniani <a.paterniani@swapp-eng.it>
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* Copyright (C) 2007 David Brownell (simplification, cleanup)
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*/
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#include <linux/init.h>
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#include <linux/ioctl.h>
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#include <linux/fs.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/list.h>
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#include <linux/errno.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/property.h>
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#include <linux/slab.h>
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#include <linux/compat.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spidev.h>
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#include <linux/uaccess.h>
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/*
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* This supports access to SPI devices using normal userspace I/O calls.
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* Note that while traditional UNIX/POSIX I/O semantics are half duplex,
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* and often mask message boundaries, full SPI support requires full duplex
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* transfers. There are several kinds of internal message boundaries to
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* handle chipselect management and other protocol options.
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*
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* SPI has a character major number assigned. We allocate minor numbers
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* dynamically using a bitmask. You must use hotplug tools, such as udev
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* (or mdev with busybox) to create and destroy the /dev/spidevB.C device
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* nodes, since there is no fixed association of minor numbers with any
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* particular SPI bus or device.
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*/
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#define SPIDEV_MAJOR 153 /* assigned */
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#define N_SPI_MINORS 32 /* ... up to 256 */
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static DECLARE_BITMAP(minors, N_SPI_MINORS);
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static_assert(N_SPI_MINORS > 0 && N_SPI_MINORS <= 256);
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/* Bit masks for spi_device.mode management. Note that incorrect
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* settings for some settings can cause *lots* of trouble for other
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* devices on a shared bus:
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*
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* - CS_HIGH ... this device will be active when it shouldn't be
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* - 3WIRE ... when active, it won't behave as it should
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* - NO_CS ... there will be no explicit message boundaries; this
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* is completely incompatible with the shared bus model
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* - READY ... transfers may proceed when they shouldn't.
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*
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* REVISIT should changing those flags be privileged?
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*/
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#define SPI_MODE_MASK (SPI_MODE_X_MASK | SPI_CS_HIGH \
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| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
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| SPI_NO_CS | SPI_READY | SPI_TX_DUAL \
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| SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL \
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| SPI_RX_QUAD | SPI_RX_OCTAL \
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| SPI_RX_CPHA_FLIP)
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struct spidev_data {
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dev_t devt;
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struct mutex spi_lock;
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struct spi_device *spi;
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struct list_head device_entry;
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/* TX/RX buffers are NULL unless this device is open (users > 0) */
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struct mutex buf_lock;
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unsigned users;
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u8 *tx_buffer;
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u8 *rx_buffer;
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u32 speed_hz;
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};
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static LIST_HEAD(device_list);
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static DEFINE_MUTEX(device_list_lock);
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static unsigned bufsiz = 4096;
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module_param(bufsiz, uint, S_IRUGO);
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MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");
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/*-------------------------------------------------------------------------*/
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static ssize_t
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spidev_sync_unlocked(struct spi_device *spi, struct spi_message *message)
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{
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ssize_t status;
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status = spi_sync(spi, message);
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if (status == 0)
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status = message->actual_length;
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return status;
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}
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static ssize_t
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spidev_sync(struct spidev_data *spidev, struct spi_message *message)
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{
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ssize_t status;
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struct spi_device *spi;
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mutex_lock(&spidev->spi_lock);
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spi = spidev->spi;
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if (spi == NULL)
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status = -ESHUTDOWN;
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else
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status = spidev_sync_unlocked(spi, message);
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mutex_unlock(&spidev->spi_lock);
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return status;
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}
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static inline ssize_t
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spidev_sync_write(struct spidev_data *spidev, size_t len)
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{
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struct spi_transfer t = {
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.tx_buf = spidev->tx_buffer,
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.len = len,
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.speed_hz = spidev->speed_hz,
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};
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struct spi_message m;
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spi_message_init(&m);
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spi_message_add_tail(&t, &m);
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return spidev_sync(spidev, &m);
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}
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static inline ssize_t
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spidev_sync_read(struct spidev_data *spidev, size_t len)
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{
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struct spi_transfer t = {
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.rx_buf = spidev->rx_buffer,
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.len = len,
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.speed_hz = spidev->speed_hz,
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};
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struct spi_message m;
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spi_message_init(&m);
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spi_message_add_tail(&t, &m);
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return spidev_sync(spidev, &m);
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}
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/*-------------------------------------------------------------------------*/
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/* Read-only message with current device setup */
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static ssize_t
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spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
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{
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struct spidev_data *spidev;
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ssize_t status;
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/* chipselect only toggles at start or end of operation */
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if (count > bufsiz)
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return -EMSGSIZE;
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spidev = filp->private_data;
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mutex_lock(&spidev->buf_lock);
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status = spidev_sync_read(spidev, count);
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if (status > 0) {
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unsigned long missing;
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missing = copy_to_user(buf, spidev->rx_buffer, status);
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if (missing == status)
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status = -EFAULT;
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else
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status = status - missing;
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}
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mutex_unlock(&spidev->buf_lock);
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return status;
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}
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/* Write-only message with current device setup */
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static ssize_t
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spidev_write(struct file *filp, const char __user *buf,
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size_t count, loff_t *f_pos)
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{
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struct spidev_data *spidev;
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ssize_t status;
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unsigned long missing;
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/* chipselect only toggles at start or end of operation */
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if (count > bufsiz)
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return -EMSGSIZE;
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spidev = filp->private_data;
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mutex_lock(&spidev->buf_lock);
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missing = copy_from_user(spidev->tx_buffer, buf, count);
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if (missing == 0)
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status = spidev_sync_write(spidev, count);
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else
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status = -EFAULT;
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mutex_unlock(&spidev->buf_lock);
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return status;
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}
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static int spidev_message(struct spidev_data *spidev,
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struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
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{
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struct spi_message msg;
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struct spi_transfer *k_xfers;
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struct spi_transfer *k_tmp;
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struct spi_ioc_transfer *u_tmp;
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unsigned n, total, tx_total, rx_total;
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u8 *tx_buf, *rx_buf;
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int status = -EFAULT;
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spi_message_init(&msg);
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k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL);
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if (k_xfers == NULL)
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return -ENOMEM;
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/* Construct spi_message, copying any tx data to bounce buffer.
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* We walk the array of user-provided transfers, using each one
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* to initialize a kernel version of the same transfer.
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*/
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tx_buf = spidev->tx_buffer;
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rx_buf = spidev->rx_buffer;
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total = 0;
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tx_total = 0;
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rx_total = 0;
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for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
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n;
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n--, k_tmp++, u_tmp++) {
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/* Ensure that also following allocations from rx_buf/tx_buf will meet
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* DMA alignment requirements.
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*/
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unsigned int len_aligned = ALIGN(u_tmp->len, ARCH_KMALLOC_MINALIGN);
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k_tmp->len = u_tmp->len;
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total += k_tmp->len;
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/* Since the function returns the total length of transfers
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* on success, restrict the total to positive int values to
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* avoid the return value looking like an error. Also check
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* each transfer length to avoid arithmetic overflow.
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*/
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if (total > INT_MAX || k_tmp->len > INT_MAX) {
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status = -EMSGSIZE;
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goto done;
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}
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if (u_tmp->rx_buf) {
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/* this transfer needs space in RX bounce buffer */
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rx_total += len_aligned;
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if (rx_total > bufsiz) {
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status = -EMSGSIZE;
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goto done;
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}
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k_tmp->rx_buf = rx_buf;
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rx_buf += len_aligned;
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}
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if (u_tmp->tx_buf) {
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/* this transfer needs space in TX bounce buffer */
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tx_total += len_aligned;
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if (tx_total > bufsiz) {
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status = -EMSGSIZE;
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goto done;
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}
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k_tmp->tx_buf = tx_buf;
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if (copy_from_user(tx_buf, (const u8 __user *)
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(uintptr_t) u_tmp->tx_buf,
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u_tmp->len))
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goto done;
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tx_buf += len_aligned;
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}
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k_tmp->cs_change = !!u_tmp->cs_change;
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k_tmp->tx_nbits = u_tmp->tx_nbits;
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k_tmp->rx_nbits = u_tmp->rx_nbits;
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k_tmp->bits_per_word = u_tmp->bits_per_word;
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k_tmp->delay.value = u_tmp->delay_usecs;
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k_tmp->delay.unit = SPI_DELAY_UNIT_USECS;
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k_tmp->speed_hz = u_tmp->speed_hz;
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k_tmp->word_delay.value = u_tmp->word_delay_usecs;
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k_tmp->word_delay.unit = SPI_DELAY_UNIT_USECS;
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if (!k_tmp->speed_hz)
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k_tmp->speed_hz = spidev->speed_hz;
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#ifdef VERBOSE
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dev_dbg(&spidev->spi->dev,
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" xfer len %u %s%s%s%dbits %u usec %u usec %uHz\n",
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k_tmp->len,
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k_tmp->rx_buf ? "rx " : "",
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k_tmp->tx_buf ? "tx " : "",
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k_tmp->cs_change ? "cs " : "",
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k_tmp->bits_per_word ? : spidev->spi->bits_per_word,
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k_tmp->delay.value,
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k_tmp->word_delay.value,
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k_tmp->speed_hz ? : spidev->spi->max_speed_hz);
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#endif
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spi_message_add_tail(k_tmp, &msg);
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}
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status = spidev_sync_unlocked(spidev->spi, &msg);
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if (status < 0)
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goto done;
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/* copy any rx data out of bounce buffer */
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for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
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n;
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n--, k_tmp++, u_tmp++) {
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if (u_tmp->rx_buf) {
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if (copy_to_user((u8 __user *)
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(uintptr_t) u_tmp->rx_buf, k_tmp->rx_buf,
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u_tmp->len)) {
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status = -EFAULT;
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goto done;
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}
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}
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}
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status = total;
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done:
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kfree(k_xfers);
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return status;
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}
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static struct spi_ioc_transfer *
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spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user *u_ioc,
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unsigned *n_ioc)
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{
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u32 tmp;
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/* Check type, command number and direction */
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if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC
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|| _IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
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|| _IOC_DIR(cmd) != _IOC_WRITE)
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return ERR_PTR(-ENOTTY);
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tmp = _IOC_SIZE(cmd);
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if ((tmp % sizeof(struct spi_ioc_transfer)) != 0)
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return ERR_PTR(-EINVAL);
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*n_ioc = tmp / sizeof(struct spi_ioc_transfer);
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if (*n_ioc == 0)
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return NULL;
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/* copy into scratch area */
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return memdup_user(u_ioc, tmp);
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}
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static long
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spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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{
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int retval = 0;
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struct spidev_data *spidev;
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struct spi_device *spi;
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u32 tmp;
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unsigned n_ioc;
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struct spi_ioc_transfer *ioc;
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/* Check type and command number */
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if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
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return -ENOTTY;
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/* guard against device removal before, or while,
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* we issue this ioctl.
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*/
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spidev = filp->private_data;
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mutex_lock(&spidev->spi_lock);
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spi = spi_dev_get(spidev->spi);
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if (spi == NULL) {
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mutex_unlock(&spidev->spi_lock);
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return -ESHUTDOWN;
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}
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/* use the buffer lock here for triple duty:
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* - prevent I/O (from us) so calling spi_setup() is safe;
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* - prevent concurrent SPI_IOC_WR_* from morphing
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* data fields while SPI_IOC_RD_* reads them;
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* - SPI_IOC_MESSAGE needs the buffer locked "normally".
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*/
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mutex_lock(&spidev->buf_lock);
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switch (cmd) {
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/* read requests */
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case SPI_IOC_RD_MODE:
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case SPI_IOC_RD_MODE32:
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tmp = spi->mode;
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{
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struct spi_controller *ctlr = spi->controller;
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if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods &&
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ctlr->cs_gpiods[spi->chip_select])
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tmp &= ~SPI_CS_HIGH;
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}
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if (cmd == SPI_IOC_RD_MODE)
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retval = put_user(tmp & SPI_MODE_MASK,
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(__u8 __user *)arg);
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else
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retval = put_user(tmp & SPI_MODE_MASK,
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(__u32 __user *)arg);
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break;
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case SPI_IOC_RD_LSB_FIRST:
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retval = put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0,
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(__u8 __user *)arg);
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break;
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case SPI_IOC_RD_BITS_PER_WORD:
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retval = put_user(spi->bits_per_word, (__u8 __user *)arg);
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break;
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case SPI_IOC_RD_MAX_SPEED_HZ:
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retval = put_user(spidev->speed_hz, (__u32 __user *)arg);
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break;
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/* write requests */
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case SPI_IOC_WR_MODE:
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case SPI_IOC_WR_MODE32:
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if (cmd == SPI_IOC_WR_MODE)
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retval = get_user(tmp, (u8 __user *)arg);
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else
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retval = get_user(tmp, (u32 __user *)arg);
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if (retval == 0) {
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struct spi_controller *ctlr = spi->controller;
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u32 save = spi->mode;
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if (tmp & ~SPI_MODE_MASK) {
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retval = -EINVAL;
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break;
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}
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if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods &&
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ctlr->cs_gpiods[spi->chip_select])
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tmp |= SPI_CS_HIGH;
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tmp |= spi->mode & ~SPI_MODE_MASK;
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spi->mode = tmp & SPI_MODE_USER_MASK;
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retval = spi_setup(spi);
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if (retval < 0)
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spi->mode = save;
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else
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dev_dbg(&spi->dev, "spi mode %x\n", tmp);
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}
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break;
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case SPI_IOC_WR_LSB_FIRST:
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retval = get_user(tmp, (__u8 __user *)arg);
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if (retval == 0) {
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u32 save = spi->mode;
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if (tmp)
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spi->mode |= SPI_LSB_FIRST;
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else
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spi->mode &= ~SPI_LSB_FIRST;
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retval = spi_setup(spi);
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if (retval < 0)
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spi->mode = save;
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else
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dev_dbg(&spi->dev, "%csb first\n",
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tmp ? 'l' : 'm');
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}
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break;
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case SPI_IOC_WR_BITS_PER_WORD:
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retval = get_user(tmp, (__u8 __user *)arg);
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if (retval == 0) {
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u8 save = spi->bits_per_word;
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spi->bits_per_word = tmp;
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retval = spi_setup(spi);
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if (retval < 0)
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spi->bits_per_word = save;
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else
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dev_dbg(&spi->dev, "%d bits per word\n", tmp);
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}
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break;
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case SPI_IOC_WR_MAX_SPEED_HZ: {
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u32 save;
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retval = get_user(tmp, (__u32 __user *)arg);
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if (retval)
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break;
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if (tmp == 0) {
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retval = -EINVAL;
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break;
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}
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save = spi->max_speed_hz;
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spi->max_speed_hz = tmp;
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retval = spi_setup(spi);
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if (retval == 0) {
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spidev->speed_hz = tmp;
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dev_dbg(&spi->dev, "%d Hz (max)\n", spidev->speed_hz);
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}
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|
|
|
spi->max_speed_hz = save;
|
|
break;
|
|
}
|
|
default:
|
|
/* segmented and/or full-duplex I/O request */
|
|
/* Check message and copy into scratch area */
|
|
ioc = spidev_get_ioc_message(cmd,
|
|
(struct spi_ioc_transfer __user *)arg, &n_ioc);
|
|
if (IS_ERR(ioc)) {
|
|
retval = PTR_ERR(ioc);
|
|
break;
|
|
}
|
|
if (!ioc)
|
|
break; /* n_ioc is also 0 */
|
|
|
|
/* translate to spi_message, execute */
|
|
retval = spidev_message(spidev, ioc, n_ioc);
|
|
kfree(ioc);
|
|
break;
|
|
}
|
|
|
|
mutex_unlock(&spidev->buf_lock);
|
|
spi_dev_put(spi);
|
|
mutex_unlock(&spidev->spi_lock);
|
|
return retval;
|
|
}
|
|
|
|
#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.
|
|
*/
|
|
spidev = filp->private_data;
|
|
mutex_lock(&spidev->spi_lock);
|
|
spi = spi_dev_get(spidev->spi);
|
|
if (spi == NULL) {
|
|
mutex_unlock(&spidev->spi_lock);
|
|
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);
|
|
mutex_unlock(&spidev->spi_lock);
|
|
return retval;
|
|
}
|
|
|
|
static long
|
|
spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
|
|
{
|
|
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 = NULL, *iter;
|
|
int status = -ENXIO;
|
|
|
|
mutex_lock(&device_list_lock);
|
|
|
|
list_for_each_entry(iter, &device_list, device_entry) {
|
|
if (iter->devt == inode->i_rdev) {
|
|
status = 0;
|
|
spidev = iter;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!spidev) {
|
|
pr_debug("spidev: nothing for minor %d\n", iminor(inode));
|
|
goto err_find_dev;
|
|
}
|
|
|
|
if (!spidev->tx_buffer) {
|
|
spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL);
|
|
if (!spidev->tx_buffer) {
|
|
status = -ENOMEM;
|
|
goto err_find_dev;
|
|
}
|
|
}
|
|
|
|
if (!spidev->rx_buffer) {
|
|
spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL);
|
|
if (!spidev->rx_buffer) {
|
|
status = -ENOMEM;
|
|
goto err_alloc_rx_buf;
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
mutex_lock(&spidev->spi_lock);
|
|
/* ... after we unbound from the underlying device? */
|
|
dofree = (spidev->spi == NULL);
|
|
mutex_unlock(&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 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 const struct spi_device_id spidev_spi_ids[] = {
|
|
{ .name = "dh2228fv" },
|
|
{ .name = "ltc2488" },
|
|
{ .name = "sx1301" },
|
|
{ .name = "bk4" },
|
|
{ .name = "dhcom-board" },
|
|
{ .name = "m53cpld" },
|
|
{ .name = "spi-petra" },
|
|
{ .name = "spi-authenta" },
|
|
{ .name = "em3581" },
|
|
{ .name = "si3210" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, spidev_spi_ids);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int spidev_of_check(struct device *dev)
|
|
{
|
|
if (device_property_match_string(dev, "compatible", "spidev") < 0)
|
|
return 0;
|
|
|
|
dev_err(dev, "spidev listed directly in DT is not supported\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
static const struct of_device_id spidev_dt_ids[] = {
|
|
{ .compatible = "cisco,spi-petra", .data = &spidev_of_check },
|
|
{ .compatible = "dh,dhcom-board", .data = &spidev_of_check },
|
|
{ .compatible = "lineartechnology,ltc2488", .data = &spidev_of_check },
|
|
{ .compatible = "lwn,bk4", .data = &spidev_of_check },
|
|
{ .compatible = "menlo,m53cpld", .data = &spidev_of_check },
|
|
{ .compatible = "micron,spi-authenta", .data = &spidev_of_check },
|
|
{ .compatible = "rohm,dh2228fv", .data = &spidev_of_check },
|
|
{ .compatible = "semtech,sx1301", .data = &spidev_of_check },
|
|
{ .compatible = "silabs,em3581", .data = &spidev_of_check },
|
|
{ .compatible = "silabs,si3210", .data = &spidev_of_check },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, spidev_dt_ids);
|
|
|
|
/* Dummy SPI devices not to be used in production systems */
|
|
static int spidev_acpi_check(struct device *dev)
|
|
{
|
|
dev_warn(dev, "do not use this driver in production systems!\n");
|
|
return 0;
|
|
}
|
|
|
|
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", (kernel_ulong_t)&spidev_acpi_check },
|
|
{ "SPT0002", (kernel_ulong_t)&spidev_acpi_check },
|
|
{ "SPT0003", (kernel_ulong_t)&spidev_acpi_check },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
static int spidev_probe(struct spi_device *spi)
|
|
{
|
|
int (*match)(struct device *dev);
|
|
struct spidev_data *spidev;
|
|
int status;
|
|
unsigned long minor;
|
|
|
|
match = device_get_match_data(&spi->dev);
|
|
if (match) {
|
|
status = match(&spi->dev);
|
|
if (status)
|
|
return status;
|
|
}
|
|
|
|
/* Allocate driver data */
|
|
spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
|
|
if (!spidev)
|
|
return -ENOMEM;
|
|
|
|
/* Initialize the driver data */
|
|
spidev->spi = spi;
|
|
mutex_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 = 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;
|
|
|
|
if (status == 0)
|
|
spi_set_drvdata(spi, spidev);
|
|
else
|
|
kfree(spidev);
|
|
|
|
return status;
|
|
}
|
|
|
|
static void 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 */
|
|
mutex_lock(&spidev->spi_lock);
|
|
spidev->spi = NULL;
|
|
mutex_unlock(&spidev->spi_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);
|
|
}
|
|
|
|
static struct spi_driver spidev_spi_driver = {
|
|
.driver = {
|
|
.name = "spidev",
|
|
.of_match_table = spidev_dt_ids,
|
|
.acpi_match_table = spidev_acpi_ids,
|
|
},
|
|
.probe = spidev_probe,
|
|
.remove = spidev_remove,
|
|
.id_table = spidev_spi_ids,
|
|
|
|
/* 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.
|
|
*/
|
|
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");
|