/* 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/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; DEFINE_MUTEX(comedi_drivers_list_lock); 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; } /** * comedi_alloc_devpriv() - Allocate memory for the device private data. * @dev: comedi_device struct * @size: size of the memory to allocate */ void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size) { dev->private = kzalloc(size, GFP_KERNEL); return dev->private; } EXPORT_SYMBOL_GPL(comedi_alloc_devpriv); 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 comedi_device_detach_cleanup(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) { comedi_device_cancel_all(dev); down_write(&dev->attach_lock); dev->attached = false; dev->detach_count++; if (dev->driver) dev->driver->detach(dev); comedi_device_detach_cleanup(dev); up_write(&dev->attach_lock); } 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; } /** * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices. * @dev: comedi_device struct * @s: comedi_subdevice struct * @insn: comedi_insn struct * @data: parameters for the @insn * @mask: io_bits mask for grouped channels */ int comedi_dio_insn_config(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data, unsigned int mask) { unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec); if (!mask) mask = chan_mask; switch (data[0]) { case INSN_CONFIG_DIO_INPUT: s->io_bits &= ~mask; break; case INSN_CONFIG_DIO_OUTPUT: s->io_bits |= mask; break; case INSN_CONFIG_DIO_QUERY: data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT; return insn->n; default: return -EINVAL; } return 0; } EXPORT_SYMBOL_GPL(comedi_dio_insn_config); /** * comedi_dio_update_state() - update the internal state of DIO subdevices. * @s: comedi_subdevice struct * @data: the channel mask and bits to update */ unsigned int comedi_dio_update_state(struct comedi_subdevice *s, unsigned int *data) { unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1) : 0xffffffff; unsigned int mask = data[0] & chanmask; unsigned int bits = data[1]; if (mask) { s->state &= ~mask; s->state |= (bits & mask); } return mask; } EXPORT_SYMBOL_GPL(comedi_dio_update_state); 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->type == COMEDI_SUBD_DO) { if (s->n_chan < 32) s->io_bits = (1 << s->n_chan) - 1; else s->io_bits = 0xffffffff; } 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; down_write(&dev->attach_lock); dev->attached = true; up_write(&dev->attach_lock); 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 < 0 ? ret : 0; } 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; mutex_lock(&comedi_drivers_list_lock); 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); } ret = -EIO; goto out; } 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); ret = -ENOSYS; goto out; } /* 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(driv->module); } /* On success, the driver module count has been incremented. */ out: mutex_unlock(&comedi_drivers_list_lock); 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)) { dev_warn(hardware_device, "driver '%s' could not create device.\n", driver->driver_name); 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); mutex_unlock(&dev->mutex); if (ret < 0) { dev_warn(hardware_device, "driver '%s' failed to auto-configure device.\n", driver->driver_name); comedi_release_hardware_device(hardware_device); } else { /* * class_dev should be set properly here * after a successful auto config */ dev_info(dev->class_dev, "driver '%s' has successfully auto-configured '%s'.\n", driver->driver_name, dev->board_name); } 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) { mutex_lock(&comedi_drivers_list_lock); driver->next = comedi_drivers; comedi_drivers = driver; mutex_unlock(&comedi_drivers_list_lock); return 0; } EXPORT_SYMBOL_GPL(comedi_driver_register); void comedi_driver_unregister(struct comedi_driver *driver) { struct comedi_driver *prev; int i; /* unlink the driver */ mutex_lock(&comedi_drivers_list_lock); if (comedi_drivers == driver) { comedi_drivers = driver->next; } else { for (prev = comedi_drivers; prev->next; prev = prev->next) { if (prev->next == driver) { prev->next = driver->next; break; } } } mutex_unlock(&comedi_drivers_list_lock); /* check for devices using this driver */ for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { struct comedi_device *dev = comedi_dev_get_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); comedi_dev_put(dev); } } EXPORT_SYMBOL_GPL(comedi_driver_unregister);