| /* |
| module/drivers.c |
| functions for manipulating drivers |
| |
| COMEDI - Linux Control and Measurement Device Interface |
| Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org> |
| |
| 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. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/kconfig.h> |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/fcntl.h> |
| #include <linux/delay.h> |
| #include <linux/ioport.h> |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <linux/highmem.h> /* for SuSE brokenness */ |
| #include <linux/vmalloc.h> |
| #include <linux/cdev.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/io.h> |
| #include <linux/interrupt.h> |
| #include <linux/firmware.h> |
| |
| #include "comedidev.h" |
| #include "comedi_internal.h" |
| |
| struct comedi_driver *comedi_drivers; |
| |
| int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev) |
| { |
| if (hw_dev == dev->hw_dev) |
| return 0; |
| if (dev->hw_dev != NULL) |
| return -EEXIST; |
| dev->hw_dev = get_device(hw_dev); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(comedi_set_hw_dev); |
| |
| static void comedi_clear_hw_dev(struct comedi_device *dev) |
| { |
| put_device(dev->hw_dev); |
| dev->hw_dev = NULL; |
| } |
| |
| int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices) |
| { |
| struct comedi_subdevice *s; |
| int i; |
| |
| if (num_subdevices < 1) |
| return -EINVAL; |
| |
| s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL); |
| if (!s) |
| return -ENOMEM; |
| dev->subdevices = s; |
| dev->n_subdevices = num_subdevices; |
| |
| for (i = 0; i < num_subdevices; ++i) { |
| s = &dev->subdevices[i]; |
| s->device = dev; |
| s->index = i; |
| s->async_dma_dir = DMA_NONE; |
| spin_lock_init(&s->spin_lock); |
| s->minor = -1; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(comedi_alloc_subdevices); |
| |
| static void cleanup_device(struct comedi_device *dev) |
| { |
| int i; |
| struct comedi_subdevice *s; |
| |
| if (dev->subdevices) { |
| for (i = 0; i < dev->n_subdevices; i++) { |
| s = &dev->subdevices[i]; |
| if (s->runflags & SRF_FREE_SPRIV) |
| kfree(s->private); |
| comedi_free_subdevice_minor(s); |
| if (s->async) { |
| comedi_buf_alloc(dev, s, 0); |
| kfree(s->async); |
| } |
| } |
| kfree(dev->subdevices); |
| dev->subdevices = NULL; |
| dev->n_subdevices = 0; |
| } |
| kfree(dev->private); |
| dev->private = NULL; |
| dev->driver = NULL; |
| dev->board_name = NULL; |
| dev->board_ptr = NULL; |
| dev->iobase = 0; |
| dev->iolen = 0; |
| dev->ioenabled = false; |
| dev->irq = 0; |
| dev->read_subdev = NULL; |
| dev->write_subdev = NULL; |
| dev->open = NULL; |
| dev->close = NULL; |
| comedi_clear_hw_dev(dev); |
| } |
| |
| void comedi_device_detach(struct comedi_device *dev) |
| { |
| dev->attached = false; |
| if (dev->driver) |
| dev->driver->detach(dev); |
| cleanup_device(dev); |
| } |
| |
| static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) |
| { |
| return -EINVAL; |
| } |
| |
| int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, |
| struct comedi_insn *insn, unsigned int *data) |
| { |
| return -EINVAL; |
| } |
| |
| static int insn_rw_emulate_bits(struct comedi_device *dev, |
| struct comedi_subdevice *s, |
| struct comedi_insn *insn, unsigned int *data) |
| { |
| struct comedi_insn new_insn; |
| int ret; |
| static const unsigned channels_per_bitfield = 32; |
| |
| unsigned chan = CR_CHAN(insn->chanspec); |
| const unsigned base_bitfield_channel = |
| (chan < channels_per_bitfield) ? 0 : chan; |
| unsigned int new_data[2]; |
| memset(new_data, 0, sizeof(new_data)); |
| memset(&new_insn, 0, sizeof(new_insn)); |
| new_insn.insn = INSN_BITS; |
| new_insn.chanspec = base_bitfield_channel; |
| new_insn.n = 2; |
| new_insn.subdev = insn->subdev; |
| |
| if (insn->insn == INSN_WRITE) { |
| if (!(s->subdev_flags & SDF_WRITABLE)) |
| return -EINVAL; |
| new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */ |
| new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) |
| : 0; /* bits */ |
| } |
| |
| ret = s->insn_bits(dev, s, &new_insn, new_data); |
| if (ret < 0) |
| return ret; |
| |
| if (insn->insn == INSN_READ) |
| data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1; |
| |
| return 1; |
| } |
| |
| static int __comedi_device_postconfig_async(struct comedi_device *dev, |
| struct comedi_subdevice *s) |
| { |
| struct comedi_async *async; |
| unsigned int buf_size; |
| int ret; |
| |
| if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) { |
| dev_warn(dev->class_dev, |
| "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n"); |
| return -EINVAL; |
| } |
| if (!s->do_cmdtest) { |
| dev_warn(dev->class_dev, |
| "async subdevices must have a do_cmdtest() function\n"); |
| return -EINVAL; |
| } |
| |
| async = kzalloc(sizeof(*async), GFP_KERNEL); |
| if (!async) |
| return -ENOMEM; |
| |
| init_waitqueue_head(&async->wait_head); |
| async->subdevice = s; |
| s->async = async; |
| |
| async->max_bufsize = comedi_default_buf_maxsize_kb * 1024; |
| buf_size = comedi_default_buf_size_kb * 1024; |
| if (buf_size > async->max_bufsize) |
| buf_size = async->max_bufsize; |
| |
| if (comedi_buf_alloc(dev, s, buf_size) < 0) { |
| dev_warn(dev->class_dev, "Buffer allocation failed\n"); |
| return -ENOMEM; |
| } |
| if (s->buf_change) { |
| ret = s->buf_change(dev, s, buf_size); |
| if (ret < 0) |
| return ret; |
| } |
| |
| comedi_alloc_subdevice_minor(s); |
| |
| return 0; |
| } |
| |
| static int __comedi_device_postconfig(struct comedi_device *dev) |
| { |
| struct comedi_subdevice *s; |
| int ret; |
| int i; |
| |
| for (i = 0; i < dev->n_subdevices; i++) { |
| s = &dev->subdevices[i]; |
| |
| if (s->type == COMEDI_SUBD_UNUSED) |
| continue; |
| |
| if (s->len_chanlist == 0) |
| s->len_chanlist = 1; |
| |
| if (s->do_cmd) { |
| ret = __comedi_device_postconfig_async(dev, s); |
| if (ret) |
| return ret; |
| } |
| |
| if (!s->range_table && !s->range_table_list) |
| s->range_table = &range_unknown; |
| |
| if (!s->insn_read && s->insn_bits) |
| s->insn_read = insn_rw_emulate_bits; |
| if (!s->insn_write && s->insn_bits) |
| s->insn_write = insn_rw_emulate_bits; |
| |
| if (!s->insn_read) |
| s->insn_read = insn_inval; |
| if (!s->insn_write) |
| s->insn_write = insn_inval; |
| if (!s->insn_bits) |
| s->insn_bits = insn_inval; |
| if (!s->insn_config) |
| s->insn_config = insn_inval; |
| |
| if (!s->poll) |
| s->poll = poll_invalid; |
| } |
| |
| return 0; |
| } |
| |
| /* do a little post-config cleanup */ |
| static int comedi_device_postconfig(struct comedi_device *dev) |
| { |
| int ret; |
| |
| ret = __comedi_device_postconfig(dev); |
| if (ret < 0) |
| return ret; |
| smp_wmb(); |
| dev->attached = true; |
| return 0; |
| } |
| |
| /* |
| * Generic recognize function for drivers that register their supported |
| * board names. |
| * |
| * 'driv->board_name' points to a 'const char *' member within the |
| * zeroth element of an array of some private board information |
| * structure, say 'struct foo_board' containing a member 'const char |
| * *board_name' that is initialized to point to a board name string that |
| * is one of the candidates matched against this function's 'name' |
| * parameter. |
| * |
| * 'driv->offset' is the size of the private board information |
| * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is |
| * the length of the array of private board information structures. |
| * |
| * If one of the board names in the array of private board information |
| * structures matches the name supplied to this function, the function |
| * returns a pointer to the pointer to the board name, otherwise it |
| * returns NULL. The return value ends up in the 'board_ptr' member of |
| * a 'struct comedi_device' that the low-level comedi driver's |
| * 'attach()' hook can convert to a point to a particular element of its |
| * array of private board information structures by subtracting the |
| * offset of the member that points to the board name. (No subtraction |
| * is required if the board name pointer is the first member of the |
| * private board information structure, which is generally the case.) |
| */ |
| static void *comedi_recognize(struct comedi_driver *driv, const char *name) |
| { |
| char **name_ptr = (char **)driv->board_name; |
| int i; |
| |
| for (i = 0; i < driv->num_names; i++) { |
| if (strcmp(*name_ptr, name) == 0) |
| return name_ptr; |
| name_ptr = (void *)name_ptr + driv->offset; |
| } |
| |
| return NULL; |
| } |
| |
| static void comedi_report_boards(struct comedi_driver *driv) |
| { |
| unsigned int i; |
| const char *const *name_ptr; |
| |
| pr_info("comedi: valid board names for %s driver are:\n", |
| driv->driver_name); |
| |
| name_ptr = driv->board_name; |
| for (i = 0; i < driv->num_names; i++) { |
| pr_info(" %s\n", *name_ptr); |
| name_ptr = (const char **)((char *)name_ptr + driv->offset); |
| } |
| |
| if (driv->num_names == 0) |
| pr_info(" %s\n", driv->driver_name); |
| } |
| |
| /** |
| * comedi_load_firmware() - Request and load firmware for a device. |
| * @dev: comedi_device struct |
| * @hw_device: device struct for the comedi_device |
| * @name: the name of the firmware image |
| * @cb: callback to the upload the firmware image |
| * @context: private context from the driver |
| */ |
| int comedi_load_firmware(struct comedi_device *dev, |
| struct device *device, |
| const char *name, |
| int (*cb)(struct comedi_device *dev, |
| const u8 *data, size_t size, |
| unsigned long context), |
| unsigned long context) |
| { |
| const struct firmware *fw; |
| int ret; |
| |
| if (!cb) |
| return -EINVAL; |
| |
| ret = request_firmware(&fw, name, device); |
| if (ret == 0) { |
| ret = cb(dev, fw->data, fw->size, context); |
| release_firmware(fw); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(comedi_load_firmware); |
| |
| /** |
| * __comedi_request_region() - Request an I/O reqion for a legacy driver. |
| * @dev: comedi_device struct |
| * @start: base address of the I/O reqion |
| * @len: length of the I/O region |
| */ |
| int __comedi_request_region(struct comedi_device *dev, |
| unsigned long start, unsigned long len) |
| { |
| if (!start) { |
| dev_warn(dev->class_dev, |
| "%s: a I/O base address must be specified\n", |
| dev->board_name); |
| return -EINVAL; |
| } |
| |
| if (!request_region(start, len, dev->board_name)) { |
| dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n", |
| dev->board_name, start, len); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(__comedi_request_region); |
| |
| /** |
| * comedi_request_region() - Request an I/O reqion for a legacy driver. |
| * @dev: comedi_device struct |
| * @start: base address of the I/O reqion |
| * @len: length of the I/O region |
| */ |
| int comedi_request_region(struct comedi_device *dev, |
| unsigned long start, unsigned long len) |
| { |
| int ret; |
| |
| ret = __comedi_request_region(dev, start, len); |
| if (ret == 0) { |
| dev->iobase = start; |
| dev->iolen = len; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(comedi_request_region); |
| |
| /** |
| * comedi_legacy_detach() - A generic (*detach) function for legacy drivers. |
| * @dev: comedi_device struct |
| */ |
| void comedi_legacy_detach(struct comedi_device *dev) |
| { |
| if (dev->irq) { |
| free_irq(dev->irq, dev); |
| dev->irq = 0; |
| } |
| if (dev->iobase && dev->iolen) { |
| release_region(dev->iobase, dev->iolen); |
| dev->iobase = 0; |
| dev->iolen = 0; |
| } |
| } |
| EXPORT_SYMBOL_GPL(comedi_legacy_detach); |
| |
| int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) |
| { |
| struct comedi_driver *driv; |
| int ret; |
| |
| if (dev->attached) |
| return -EBUSY; |
| |
| for (driv = comedi_drivers; driv; driv = driv->next) { |
| if (!try_module_get(driv->module)) |
| continue; |
| if (driv->num_names) { |
| dev->board_ptr = comedi_recognize(driv, it->board_name); |
| if (dev->board_ptr) |
| break; |
| } else if (strcmp(driv->driver_name, it->board_name) == 0) |
| break; |
| module_put(driv->module); |
| } |
| if (driv == NULL) { |
| /* recognize has failed if we get here */ |
| /* report valid board names before returning error */ |
| for (driv = comedi_drivers; driv; driv = driv->next) { |
| if (!try_module_get(driv->module)) |
| continue; |
| comedi_report_boards(driv); |
| module_put(driv->module); |
| } |
| return -EIO; |
| } |
| if (driv->attach == NULL) { |
| /* driver does not support manual configuration */ |
| dev_warn(dev->class_dev, |
| "driver '%s' does not support attach using comedi_config\n", |
| driv->driver_name); |
| module_put(driv->module); |
| return -ENOSYS; |
| } |
| /* initialize dev->driver here so |
| * comedi_error() can be called from attach */ |
| dev->driver = driv; |
| dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr |
| : dev->driver->driver_name; |
| ret = driv->attach(dev, it); |
| if (ret >= 0) |
| ret = comedi_device_postconfig(dev); |
| if (ret < 0) { |
| comedi_device_detach(dev); |
| module_put(dev->driver->module); |
| } |
| /* On success, the driver module count has been incremented. */ |
| return ret; |
| } |
| |
| int comedi_auto_config(struct device *hardware_device, |
| struct comedi_driver *driver, unsigned long context) |
| { |
| struct comedi_device *dev; |
| int ret; |
| |
| if (!hardware_device) { |
| pr_warn("BUG! comedi_auto_config called with NULL hardware_device\n"); |
| return -EINVAL; |
| } |
| if (!driver) { |
| dev_warn(hardware_device, |
| "BUG! comedi_auto_config called with NULL comedi driver\n"); |
| return -EINVAL; |
| } |
| |
| if (!driver->auto_attach) { |
| dev_warn(hardware_device, |
| "BUG! comedi driver '%s' has no auto_attach handler\n", |
| driver->driver_name); |
| return -EINVAL; |
| } |
| |
| dev = comedi_alloc_board_minor(hardware_device); |
| if (IS_ERR(dev)) |
| return PTR_ERR(dev); |
| /* Note: comedi_alloc_board_minor() locked dev->mutex. */ |
| |
| dev->driver = driver; |
| dev->board_name = dev->driver->driver_name; |
| ret = driver->auto_attach(dev, context); |
| if (ret >= 0) |
| ret = comedi_device_postconfig(dev); |
| if (ret < 0) |
| comedi_device_detach(dev); |
| mutex_unlock(&dev->mutex); |
| |
| if (ret < 0) |
| comedi_release_hardware_device(hardware_device); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(comedi_auto_config); |
| |
| void comedi_auto_unconfig(struct device *hardware_device) |
| { |
| if (hardware_device == NULL) |
| return; |
| comedi_release_hardware_device(hardware_device); |
| } |
| EXPORT_SYMBOL_GPL(comedi_auto_unconfig); |
| |
| int comedi_driver_register(struct comedi_driver *driver) |
| { |
| driver->next = comedi_drivers; |
| comedi_drivers = driver; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(comedi_driver_register); |
| |
| int comedi_driver_unregister(struct comedi_driver *driver) |
| { |
| struct comedi_driver *prev; |
| int i; |
| |
| /* check for devices using this driver */ |
| for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { |
| struct comedi_device *dev = comedi_dev_from_minor(i); |
| |
| if (!dev) |
| continue; |
| |
| mutex_lock(&dev->mutex); |
| if (dev->attached && dev->driver == driver) { |
| if (dev->use_count) |
| dev_warn(dev->class_dev, |
| "BUG! detaching device with use_count=%d\n", |
| dev->use_count); |
| comedi_device_detach(dev); |
| } |
| mutex_unlock(&dev->mutex); |
| } |
| |
| if (comedi_drivers == driver) { |
| comedi_drivers = driver->next; |
| return 0; |
| } |
| |
| for (prev = comedi_drivers; prev->next; prev = prev->next) { |
| if (prev->next == driver) { |
| prev->next = driver->next; |
| return 0; |
| } |
| } |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL_GPL(comedi_driver_unregister); |