This patch makes spidev into a bus addon rather than a separate driver. spidev character device is created for each spi slave. When a spi slave driver is bound the spidev IOCTLs return -EBUSY.
This is similar to i2c bus which alows access to any address not claimed by a kernel driver and should provide interface backwards compatible with existing spidev tools. Signed-off-by: Michal Suchanek <[email protected]> --- Documentation/spi/spidev | 40 ++--- drivers/spi/Kconfig | 2 +- drivers/spi/spi.c | 19 ++- drivers/spi/spidev.c | 370 ++++++++++++++++++++--------------------------- include/linux/spi/spi.h | 14 ++ 5 files changed, 197 insertions(+), 248 deletions(-) diff --git a/Documentation/spi/spidev b/Documentation/spi/spidev index 3d14035..dd8eac2 100644 --- a/Documentation/spi/spidev +++ b/Documentation/spi/spidev @@ -21,23 +21,14 @@ they need to access kernel interfaces (such as IRQ handlers or other layers of the driver stack) that are not accessible to userspace. -DEVICE CREATION, DRIVER BINDING -=============================== -The simplest way to arrange to use this driver is to just list it in the -spi_board_info for a device as the driver it should use: the "modalias" -entry is "spidev", matching the name of the driver exposing this API. -Set up the other device characteristics (bits per word, SPI clocking, -chipselect polarity, etc) as usual, so you won't always need to override -them later. - -(Sysfs also supports userspace driven binding/unbinding of drivers to -devices. That mechanism might be supported here in the future.) - -When you do that, the sysfs node for the SPI device will include a child -device node with a "dev" attribute that will be understood by udev or mdev. -(Larger systems will have "udev". Smaller ones may configure "mdev" into -busybox; it's less featureful, but often enough.) For a SPI device with -chipselect C on bus B, you should see: +DEVICE CREATION +=============== + +When spidev is included in the kernel, the sysfs node for the SPI device will +include a child device node with a "dev" attribute that will be understood by +udev or mdev. (Larger systems will have "udev". Smaller ones may configure +"mdev" into busybox; it's less featureful, but often enough.) For a SPI device +with chipselect C on bus B, you should see: /dev/spidevB.C ... character special device, major number 153 with a dynamically chosen minor device number. This is the node @@ -54,18 +45,9 @@ Do not try to manage the /dev character device special file nodes by hand. That's error prone, and you'd need to pay careful attention to system security issues; udev/mdev should already be configured securely. -If you unbind the "spidev" driver from that device, those two "spidev" nodes -(in sysfs and in /dev) should automatically be removed (respectively by the -kernel and by udev/mdev). You can unbind by removing the "spidev" driver -module, which will affect all devices using this driver. You can also unbind -by having kernel code remove the SPI device, probably by removing the driver -for its SPI controller (so its spi_master vanishes). - -Since this is a standard Linux device driver -- even though it just happens -to expose a low level API to userspace -- it can be associated with any number -of devices at a time. Just provide one spi_board_info record for each such -SPI device, and you'll get a /dev device node for each device. - +When a device driver is loaded for the SPI device operations on the spidev +character device return EBUSY. You can unbind a driver from the device using +the driver unbind file in sysfs. BASIC CHARACTER DEVICE API ========================== diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index f2bbb16..3806e3c 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -699,7 +699,7 @@ config SPI_ZYNQMP_GQSPI comment "SPI Protocol Masters" config SPI_SPIDEV - tristate "User mode SPI device driver support" + bool "User mode SPI device driver support" help This supports user mode SPI protocol drivers. diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 77e6e45..f3ea768 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -41,6 +41,8 @@ #define CREATE_TRACE_POINTS #include <trace/events/spi.h> +#include "spidev.h" + static void spidev_release(struct device *dev) { struct spi_device *spi = to_spi_device(dev); @@ -544,11 +546,15 @@ int spi_add_device(struct spi_device *spi) /* Device may be bound to an active driver when this returns */ status = device_add(&spi->dev); - if (status < 0) + if (status < 0) { dev_err(dev, "can't add %s, status %d\n", dev_name(&spi->dev), status); - else - dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); + goto done; + } + dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); + + if (IS_ENABLED(CONFIG_SPI_SPIDEV)) + spi_attach_spidev(spi); done: mutex_unlock(&spi_add_lock); @@ -622,6 +628,10 @@ void spi_unregister_device(struct spi_device *spi) if (spi->dev.of_node) of_node_clear_flag(spi->dev.of_node, OF_POPULATED); + + if (IS_ENABLED(CONFIG_SPI_SPIDEV)) + spi_detach_spidev(spi); + device_unregister(&spi->dev); } EXPORT_SYMBOL_GPL(spi_unregister_device); @@ -3128,6 +3138,9 @@ static int __init spi_init(void) if (IS_ENABLED(CONFIG_OF_DYNAMIC)) WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); + if (IS_ENABLED(CONFIG_SPI_SPIDEV)) + WARN_ON(spidev_init()); + return 0; err2: diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index e3c19f3..57b47d0 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -27,14 +27,14 @@ #include <linux/mutex.h> #include <linux/slab.h> #include <linux/compat.h> -#include <linux/of.h> -#include <linux/of_device.h> #include <linux/spi/spi.h> #include <linux/spi/spidev.h> #include <linux/uaccess.h> +#include "spidev.h" + /* * This supports access to SPI devices using normal userspace I/O calls. @@ -72,23 +72,6 @@ static DECLARE_BITMAP(minors, N_SPI_MINORS); | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \ | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD) -struct spidev_data { - dev_t devt; - spinlock_t spi_lock; - struct spi_device *spi; - struct list_head device_entry; - - /* TX/RX buffers are NULL unless this device is open (users > 0) */ - struct mutex buf_lock; - unsigned users; - u8 *tx_buffer; - u8 *rx_buffer; - u32 speed_hz; -}; - -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"); @@ -96,20 +79,11 @@ MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); /*-------------------------------------------------------------------------*/ static ssize_t -spidev_sync(struct spidev_data *spidev, struct spi_message *message) +spidev_sync(struct spi_device *spi, struct spi_message *message) { - DECLARE_COMPLETION_ONSTACK(done); int status; - struct spi_device *spi; - - spin_lock_irq(&spidev->spi_lock); - spi = spidev->spi; - spin_unlock_irq(&spidev->spi_lock); - if (spi == NULL) - status = -ESHUTDOWN; - else - status = spi_sync(spi, message); + status = spi_sync(spi, message); if (status == 0) status = message->actual_length; @@ -118,33 +92,33 @@ spidev_sync(struct spidev_data *spidev, struct spi_message *message) } static inline ssize_t -spidev_sync_write(struct spidev_data *spidev, size_t len) +spidev_sync_write(struct spi_device *spi, size_t len) { struct spi_transfer t = { - .tx_buf = spidev->tx_buffer, + .tx_buf = spi->tx_buffer, .len = len, - .speed_hz = spidev->speed_hz, + .speed_hz = spi->spidev_speed_hz, }; struct spi_message m; spi_message_init(&m); spi_message_add_tail(&t, &m); - return spidev_sync(spidev, &m); + return spidev_sync(spi, &m); } static inline ssize_t -spidev_sync_read(struct spidev_data *spidev, size_t len) +spidev_sync_read(struct spi_device *spi, size_t len) { struct spi_transfer t = { - .rx_buf = spidev->rx_buffer, + .rx_buf = spi->rx_buffer, .len = len, - .speed_hz = spidev->speed_hz, + .speed_hz = spi->spidev_speed_hz, }; struct spi_message m; spi_message_init(&m); spi_message_add_tail(&t, &m); - return spidev_sync(spidev, &m); + return spidev_sync(spi, &m); } /*-------------------------------------------------------------------------*/ @@ -153,27 +127,27 @@ spidev_sync_read(struct spidev_data *spidev, size_t len) static ssize_t spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) { - struct spidev_data *spidev; + struct spi_device *spi; ssize_t status = 0; /* chipselect only toggles at start or end of operation */ if (count > bufsiz) return -EMSGSIZE; - spidev = filp->private_data; + spi = filp->private_data; - mutex_lock(&spidev->buf_lock); - status = spidev_sync_read(spidev, count); + mutex_lock(&spi->buf_lock); + status = spidev_sync_read(spi, count); if (status > 0) { unsigned long missing; - missing = copy_to_user(buf, spidev->rx_buffer, status); + missing = copy_to_user(buf, spi->rx_buffer, status); if (missing == status) status = -EFAULT; else status = status - missing; } - mutex_unlock(&spidev->buf_lock); + mutex_unlock(&spi->buf_lock); return status; } @@ -183,7 +157,7 @@ static ssize_t spidev_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { - struct spidev_data *spidev; + struct spi_device *spi; ssize_t status = 0; unsigned long missing; @@ -191,20 +165,20 @@ spidev_write(struct file *filp, const char __user *buf, if (count > bufsiz) return -EMSGSIZE; - spidev = filp->private_data; + spi = filp->private_data; - mutex_lock(&spidev->buf_lock); - missing = copy_from_user(spidev->tx_buffer, buf, count); + mutex_lock(&spi->buf_lock); + missing = copy_from_user(spi->tx_buffer, buf, count); if (missing == 0) - status = spidev_sync_write(spidev, count); + status = spidev_sync_write(spi, count); else status = -EFAULT; - mutex_unlock(&spidev->buf_lock); + mutex_unlock(&spi->buf_lock); return status; } -static int spidev_message(struct spidev_data *spidev, +static int spidev_message(struct spi_device *spi, struct spi_ioc_transfer *u_xfers, unsigned n_xfers) { struct spi_message msg; @@ -224,8 +198,8 @@ static int spidev_message(struct spidev_data *spidev, * We walk the array of user-provided transfers, using each one * to initialize a kernel version of the same transfer. */ - tx_buf = spidev->tx_buffer; - rx_buf = spidev->rx_buffer; + tx_buf = spi->tx_buffer; + rx_buf = spi->rx_buffer; total = 0; tx_total = 0; rx_total = 0; @@ -281,27 +255,27 @@ static int spidev_message(struct spidev_data *spidev, k_tmp->delay_usecs = u_tmp->delay_usecs; k_tmp->speed_hz = u_tmp->speed_hz; if (!k_tmp->speed_hz) - k_tmp->speed_hz = spidev->speed_hz; + k_tmp->speed_hz = spi->spidev_speed_hz; #ifdef VERBOSE - dev_dbg(&spidev->spi->dev, + dev_dbg(&spi->dev, " xfer len %u %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->bits_per_word ? : spi->bits_per_word, u_tmp->delay_usecs, - u_tmp->speed_hz ? : spidev->spi->max_speed_hz); + u_tmp->speed_hz ? : spi->max_speed_hz); #endif spi_message_add_tail(k_tmp, &msg); } - status = spidev_sync(spidev, &msg); + status = spidev_sync(spi, &msg); if (status < 0) goto done; /* copy any rx data out of bounce buffer */ - rx_buf = spidev->rx_buffer; + rx_buf = spi->rx_buffer; for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { if (u_tmp->rx_buf) { if (__copy_to_user((u8 __user *) @@ -356,7 +330,6 @@ 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; @@ -382,21 +355,22 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) /* 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); + spi = filp->private_data; + spi = spi_dev_get(spi); if (spi == NULL) return -ESHUTDOWN; + if (spi->dev.driver) + return -EBUSY; + /* 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); + mutex_lock(&spi->buf_lock); switch (cmd) { /* read requests */ @@ -416,7 +390,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) retval = __put_user(spi->bits_per_word, (__u8 __user *)arg); break; case SPI_IOC_RD_MAX_SPEED_HZ: - retval = __put_user(spidev->speed_hz, (__u32 __user *)arg); + retval = __put_user(spi->spidev_speed_hz, (__u32 __user *)arg); break; /* write requests */ @@ -474,14 +448,14 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) } break; case SPI_IOC_WR_MAX_SPEED_HZ: - retval = __get_user(tmp, (__u32 __user *)arg); + 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) - spidev->speed_hz = tmp; + spi->spidev_speed_hz = tmp; else dev_dbg(&spi->dev, "%d Hz (max)\n", tmp); spi->max_speed_hz = save; @@ -501,12 +475,12 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) break; /* n_ioc is also 0 */ /* translate to spi_message, execute */ - retval = spidev_message(spidev, ioc, n_ioc); + retval = spidev_message(spi, ioc, n_ioc); kfree(ioc); break; } - mutex_unlock(&spidev->buf_lock); + mutex_unlock(&spi->buf_lock); spi_dev_put(spi); return retval; } @@ -518,7 +492,6 @@ spidev_compat_ioc_message(struct file *filp, unsigned int cmd, { 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; @@ -530,16 +503,17 @@ spidev_compat_ioc_message(struct file *filp, unsigned int cmd, /* 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); + spi = filp->private_data; + spi = spi_dev_get(spi); if (spi == NULL) return -ESHUTDOWN; + if (spi->dev.driver) + return -EBUSY; + /* SPI_IOC_MESSAGE needs the buffer locked "normally" */ - mutex_lock(&spidev->buf_lock); + mutex_lock(&spi->buf_lock); /* Check message and copy into scratch area */ ioc = spidev_get_ioc_message(cmd, u_ioc, &n_ioc); @@ -557,11 +531,11 @@ spidev_compat_ioc_message(struct file *filp, unsigned int cmd, } /* translate to spi_message, execute */ - retval = spidev_message(spidev, ioc, n_ioc); + retval = spidev_message(spi, ioc, n_ioc); kfree(ioc); done: - mutex_unlock(&spidev->buf_lock); + mutex_unlock(&spi->buf_lock); spi_dev_put(spi); return retval; } @@ -580,89 +554,108 @@ spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) #define spidev_compat_ioctl NULL #endif /* CONFIG_COMPAT */ +static int spidev_devt_match(struct device *dev, void *data) +{ + struct spi_device *spi = to_spi_device(dev); + dev_t devt = (dev_t) data; + int res = 0; + + spin_lock_irq(&spi->spidev_lock); + if (spi->spidev_devt == devt) + res = 1; + spin_unlock_irq(&spi->spidev_lock); + + return res; +} + static int spidev_open(struct inode *inode, struct file *filp) { - struct spidev_data *spidev; + struct spi_device *spi; + struct device *dev; int status = -ENXIO; - mutex_lock(&device_list_lock); + dev = bus_find_device(&spi_bus_type, NULL, (void *) inode->i_rdev, + spidev_devt_match); - list_for_each_entry(spidev, &device_list, device_entry) { - if (spidev->devt == inode->i_rdev) { - status = 0; - break; - } - } - - if (status) { + if (!dev) { pr_debug("spidev: nothing for minor %d\n", iminor(inode)); - goto err_find_dev; + return status; } - if (!spidev->tx_buffer) { - spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL); - if (!spidev->tx_buffer) { - dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); + spi = to_spi_device(dev); + + mutex_lock(&spi->buf_lock); + spin_lock_irq(&spi->spidev_lock); + spi->spidev_users++; + spin_unlock_irq(&spi->spidev_lock); + + if (!spi->tx_buffer) { + spi->tx_buffer = kmalloc(bufsiz, GFP_KERNEL); + if (!spi->tx_buffer) { + dev_dbg(&spi->dev, "open/ENOMEM\n"); status = -ENOMEM; goto err_find_dev; } } - if (!spidev->rx_buffer) { - spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL); - if (!spidev->rx_buffer) { - dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); + if (!spi->rx_buffer) { + spi->rx_buffer = kmalloc(bufsiz, GFP_KERNEL); + if (!spi->rx_buffer) { + dev_dbg(&spi->dev, "open/ENOMEM\n"); status = -ENOMEM; goto err_alloc_rx_buf; } } - spidev->users++; - filp->private_data = spidev; + mutex_unlock(&spi->buf_lock); + + filp->private_data = spi; nonseekable_open(inode, filp); - mutex_unlock(&device_list_lock); return 0; err_alloc_rx_buf: - kfree(spidev->tx_buffer); - spidev->tx_buffer = NULL; + kfree(spi->tx_buffer); + spi->tx_buffer = NULL; err_find_dev: - mutex_unlock(&device_list_lock); + mutex_unlock(&spi->buf_lock); + spin_lock_irq(&spi->spidev_lock); + spi->spidev_users--; + spin_unlock_irq(&spi->spidev_lock); return status; } static int spidev_release(struct inode *inode, struct file *filp) { - struct spidev_data *spidev; + struct spi_device *spi; + int do_free = 0; - mutex_lock(&device_list_lock); - spidev = filp->private_data; + spi = filp->private_data; filp->private_data = NULL; + mutex_lock(&spi->buf_lock); + spin_lock_irq(&spi->spidev_lock); + spi->spidev_users--; + /* last close? */ - spidev->users--; - if (!spidev->users) { - int dofree; + if (!spi->spidev_users) + do_free = 1; - kfree(spidev->tx_buffer); - spidev->tx_buffer = NULL; + spin_unlock_irq(&spi->spidev_lock); - kfree(spidev->rx_buffer); - spidev->rx_buffer = NULL; + if (do_free) { - spin_lock_irq(&spidev->spi_lock); - if (spidev->spi) - spidev->speed_hz = spidev->spi->max_speed_hz; + kfree(spi->tx_buffer); + spi->tx_buffer = NULL; - /* ... after we unbound from the underlying device? */ - dofree = (spidev->spi == NULL); - spin_unlock_irq(&spidev->spi_lock); + kfree(spi->rx_buffer); + spi->rx_buffer = NULL; - if (dofree) - kfree(spidev); + spi->spidev_speed_hz = spi->max_speed_hz; } - mutex_unlock(&device_list_lock); + mutex_unlock(&spi->buf_lock); + + spi_dev_put(spi); return 0; } @@ -691,152 +684,99 @@ static const struct file_operations spidev_fops = { static struct class *spidev_class; -#ifdef CONFIG_OF -static const struct of_device_id spidev_dt_ids[] = { - { .compatible = "rohm,dh2228fv" }, - { .compatible = "lineartechnology,ltc2488" }, - {}, -}; -MODULE_DEVICE_TABLE(of, spidev_dt_ids); -#endif - /*-------------------------------------------------------------------------*/ -static int spidev_probe(struct spi_device *spi) +int spi_attach_spidev(struct spi_device *spi) { - struct spidev_data *spidev; int status; unsigned long minor; - /* - * spidev should never be referenced in DT without a specific - * compatible string, it is a Linux implementation thing - * rather than a description of the hardware. - */ - if (spi->dev.of_node && !of_match_device(spidev_dt_ids, &spi->dev)) { - dev_err(&spi->dev, "buggy DT: spidev listed directly in DT\n"); - WARN_ON(spi->dev.of_node && - !of_match_device(spidev_dt_ids, &spi->dev)); - } - - /* 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); + spin_lock_init(&spi->spidev_lock); + mutex_init(&spi->buf_lock); /* 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); + spi->spidev_devt = MKDEV(SPIDEV_MAJOR, minor); + + spi->spidev = device_create(spidev_class, &spi->dev, + spi->spidev_devt, + spi, "spidev%d.%d", + spi->master->bus_num, + spi->chip_select); + status = PTR_ERR_OR_ZERO(spi->spidev); + if (status != 0) { + dev_err(&spi->dev, "Error creating spidev device!\n"); + spi->spidev_devt = 0; + spi->spidev = NULL; + } } 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); + spi->spidev_speed_hz = spi->max_speed_hz; return status; } -static int spidev_remove(struct spi_device *spi) +int spi_detach_spidev(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; - 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); + dev_t devt; + struct device *spidev; + + /* + * Make sure ops on existing fds can abort cleanly + * and prevent new ones. + */ + spin_lock_irq(&spi->spidev_lock); + devt = spi->spidev_devt; + spidev = spi->spidev; + spi->spidev_devt = 0; + spi->spidev = NULL; + spin_unlock_irq(&spi->spidev_lock); + + device_destroy(spidev_class, devt); + clear_bit(MINOR(devt), minors); return 0; } -static struct spi_driver spidev_spi_driver = { - .driver = { - .name = "spidev", - .of_match_table = of_match_ptr(spidev_dt_ids), - }, - .probe = spidev_probe, - .remove = spidev_remove, - - /* NOTE: suspend/resume methods are not necessary here. - * We don't do anything except pass the requests to/from - * the underlying controller. The refrigerator handles - * most issues; the controller driver handles the rest. - */ -}; - /*-------------------------------------------------------------------------*/ -static int __init spidev_init(void) +int __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. + * that will key udev/mdev to add/remove /dev nodes. */ BUILD_BUG_ON(N_SPI_MINORS > 256); - status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); + status = register_chrdev(SPIDEV_MAJOR, "spidev", &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); + unregister_chrdev(SPIDEV_MAJOR, "spidev"); 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); + unregister_chrdev(SPIDEV_MAJOR, "spidev"); } -module_exit(spidev_exit); +EXPORT_SYMBOL_GPL(spidev_exit); MODULE_AUTHOR("Andrea Paterniani, <[email protected]>"); MODULE_DESCRIPTION("User mode SPI device interface"); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 1f03483..7154559 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -178,6 +178,20 @@ struct spi_device { * - chipselect delays * - ... */ + + /* spidev stuff */ +#if config_enabled(CONFIG_SPI_SPIDEV) + dev_t spidev_devt; + struct device * spidev; + spinlock_t spidev_lock; + + /* TX/RX buffers are NULL unless this device is open (users > 0) */ + struct mutex buf_lock; + unsigned spidev_users; + u8 *tx_buffer; + u8 *rx_buffer; + u32 spidev_speed_hz; +#endif /*CONFIG_SPI_SPIDEV*/ }; static inline struct spi_device *to_spi_device(struct device *dev) -- 2.8.1
