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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-05 23:42:16 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-05 23:42:16 +0300 |
| commit | eed0218e8cae9fcd186c30e9fcf5fe46a87e056e (patch) | |
| tree | 799a1360b947a56d05a60433fdf60a96bf3b3348 /drivers/char/xillybus/xillybus_class.c | |
| parent | 3f8b8e7dbd79086ad48fcff33de9399f3da66a69 (diff) | |
| parent | 6f746d485fb9188dc67dce7de63d21f0c28a1f2e (diff) | |
| download | linux-eed0218e8cae9fcd186c30e9fcf5fe46a87e056e.tar.xz | |
Merge tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc driver updates from Greg KH:
"Here is the big set of char / misc and other driver subsystem updates
for 5.14-rc1. Included in here are:
- habanalabs driver updates
- fsl-mc driver updates
- comedi driver updates
- fpga driver updates
- extcon driver updates
- interconnect driver updates
- mei driver updates
- nvmem driver updates
- phy driver updates
- pnp driver updates
- soundwire driver updates
- lots of other tiny driver updates for char and misc drivers
This is looking more and more like the "various driver subsystems
mushed together" tree...
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits)
mcb: Use DEFINE_RES_MEM() helper macro and fix the end address
PNP: moved EXPORT_SYMBOL so that it immediately followed its function/variable
bus: mhi: pci-generic: Add missing 'pci_disable_pcie_error_reporting()' calls
bus: mhi: Wait for M2 state during system resume
bus: mhi: core: Fix power down latency
intel_th: Wait until port is in reset before programming it
intel_th: msu: Make contiguous buffers uncached
intel_th: Remove an unused exit point from intel_th_remove()
stm class: Spelling fix
nitro_enclaves: Set Bus Master for the NE PCI device
misc: ibmasm: Modify matricies to matrices
misc: vmw_vmci: return the correct errno code
siox: Simplify error handling via dev_err_probe()
fpga: machxo2-spi: Address warning about unused variable
lkdtm/heap: Add init_on_alloc tests
selftests/lkdtm: Enable various testable CONFIGs
lkdtm: Add CONFIG hints in errors where possible
lkdtm: Enable DOUBLE_FAULT on all architectures
lkdtm/heap: Add vmalloc linear overflow test
lkdtm/bugs: XFAIL UNALIGNED_LOAD_STORE_WRITE
...
Diffstat (limited to 'drivers/char/xillybus/xillybus_class.c')
| -rw-r--r-- | drivers/char/xillybus/xillybus_class.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/char/xillybus/xillybus_class.c b/drivers/char/xillybus/xillybus_class.c new file mode 100644 index 000000000000..5046486011c8 --- /dev/null +++ b/drivers/char/xillybus/xillybus_class.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2021 Xillybus Ltd, http://xillybus.com + * + * Driver for the Xillybus class + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/fs.h> +#include <linux/cdev.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/mutex.h> + +#include "xillybus_class.h" + +MODULE_DESCRIPTION("Driver for Xillybus class"); +MODULE_AUTHOR("Eli Billauer, Xillybus Ltd."); +MODULE_ALIAS("xillybus_class"); +MODULE_LICENSE("GPL v2"); + +static DEFINE_MUTEX(unit_mutex); +static LIST_HEAD(unit_list); +static struct class *xillybus_class; + +#define UNITNAMELEN 16 + +struct xilly_unit { + struct list_head list_entry; + void *private_data; + + struct cdev *cdev; + char name[UNITNAMELEN]; + int major; + int lowest_minor; + int num_nodes; +}; + +int xillybus_init_chrdev(struct device *dev, + const struct file_operations *fops, + struct module *owner, + void *private_data, + unsigned char *idt, unsigned int len, + int num_nodes, + const char *prefix, bool enumerate) +{ + int rc; + dev_t mdev; + int i; + char devname[48]; + + struct device *device; + size_t namelen; + struct xilly_unit *unit, *u; + + unit = kzalloc(sizeof(*unit), GFP_KERNEL); + + if (!unit) + return -ENOMEM; + + mutex_lock(&unit_mutex); + + if (!enumerate) + snprintf(unit->name, UNITNAMELEN, "%s", prefix); + + for (i = 0; enumerate; i++) { + snprintf(unit->name, UNITNAMELEN, "%s_%02d", + prefix, i); + + enumerate = false; + list_for_each_entry(u, &unit_list, list_entry) + if (!strcmp(unit->name, u->name)) { + enumerate = true; + break; + } + } + + rc = alloc_chrdev_region(&mdev, 0, num_nodes, unit->name); + + if (rc) { + dev_warn(dev, "Failed to obtain major/minors"); + goto fail_obtain; + } + + unit->major = MAJOR(mdev); + unit->lowest_minor = MINOR(mdev); + unit->num_nodes = num_nodes; + unit->private_data = private_data; + + unit->cdev = cdev_alloc(); + if (!unit->cdev) { + rc = -ENOMEM; + goto unregister_chrdev; + } + unit->cdev->ops = fops; + unit->cdev->owner = owner; + + rc = cdev_add(unit->cdev, MKDEV(unit->major, unit->lowest_minor), + unit->num_nodes); + if (rc) { + dev_err(dev, "Failed to add cdev.\n"); + /* kobject_put() is normally done by cdev_del() */ + kobject_put(&unit->cdev->kobj); + goto unregister_chrdev; + } + + for (i = 0; i < num_nodes; i++) { + namelen = strnlen(idt, len); + + if (namelen == len) { + dev_err(dev, "IDT's list of names is too short. This is exceptionally weird, because its CRC is OK\n"); + rc = -ENODEV; + goto unroll_device_create; + } + + snprintf(devname, sizeof(devname), "%s_%s", + unit->name, idt); + + len -= namelen + 1; + idt += namelen + 1; + + device = device_create(xillybus_class, + NULL, + MKDEV(unit->major, + i + unit->lowest_minor), + NULL, + "%s", devname); + + if (IS_ERR(device)) { + dev_err(dev, "Failed to create %s device. Aborting.\n", + devname); + rc = -ENODEV; + goto unroll_device_create; + } + } + + if (len) { + dev_err(dev, "IDT's list of names is too long. This is exceptionally weird, because its CRC is OK\n"); + rc = -ENODEV; + goto unroll_device_create; + } + + list_add_tail(&unit->list_entry, &unit_list); + + dev_info(dev, "Created %d device files.\n", num_nodes); + + mutex_unlock(&unit_mutex); + + return 0; + +unroll_device_create: + for (i--; i >= 0; i--) + device_destroy(xillybus_class, MKDEV(unit->major, + i + unit->lowest_minor)); + + cdev_del(unit->cdev); + +unregister_chrdev: + unregister_chrdev_region(MKDEV(unit->major, unit->lowest_minor), + unit->num_nodes); + +fail_obtain: + mutex_unlock(&unit_mutex); + + kfree(unit); + + return rc; +} +EXPORT_SYMBOL(xillybus_init_chrdev); + +void xillybus_cleanup_chrdev(void *private_data, + struct device *dev) +{ + int minor; + struct xilly_unit *unit; + bool found = false; + + mutex_lock(&unit_mutex); + + list_for_each_entry(unit, &unit_list, list_entry) + if (unit->private_data == private_data) { + found = true; + break; + } + + if (!found) { + dev_err(dev, "Weird bug: Failed to find unit\n"); + mutex_unlock(&unit_mutex); + return; + } + + for (minor = unit->lowest_minor; + minor < (unit->lowest_minor + unit->num_nodes); + minor++) + device_destroy(xillybus_class, MKDEV(unit->major, minor)); + + cdev_del(unit->cdev); + + unregister_chrdev_region(MKDEV(unit->major, unit->lowest_minor), + unit->num_nodes); + + dev_info(dev, "Removed %d device files.\n", + unit->num_nodes); + + list_del(&unit->list_entry); + kfree(unit); + + mutex_unlock(&unit_mutex); +} +EXPORT_SYMBOL(xillybus_cleanup_chrdev); + +int xillybus_find_inode(struct inode *inode, + void **private_data, int *index) +{ + int minor = iminor(inode); + int major = imajor(inode); + struct xilly_unit *unit; + bool found = false; + + mutex_lock(&unit_mutex); + + list_for_each_entry(unit, &unit_list, list_entry) + if (unit->major == major && + minor >= unit->lowest_minor && + minor < (unit->lowest_minor + unit->num_nodes)) { + found = true; + break; + } + + mutex_unlock(&unit_mutex); + + if (!found) + return -ENODEV; + + *private_data = unit->private_data; + *index = minor - unit->lowest_minor; + + return 0; +} +EXPORT_SYMBOL(xillybus_find_inode); + +static int __init xillybus_class_init(void) +{ + xillybus_class = class_create(THIS_MODULE, "xillybus"); + + if (IS_ERR(xillybus_class)) { + pr_warn("Failed to register xillybus class\n"); + + return PTR_ERR(xillybus_class); + } + return 0; +} + +static void __exit xillybus_class_exit(void) +{ + class_destroy(xillybus_class); +} + +module_init(xillybus_class_init); +module_exit(xillybus_class_exit); |
