// SPDX-License-Identifier: GPL-2.0+ /* * module/drivers.c * functions for manipulating drivers * * COMEDI - Linux Control and Measurement Device Interface * Copyright (C) 1997-2000 David A. Schleef * Copyright (C) 2002 Frank Mori Hess */ #include #include #include #include #include #include #include #include #include #include "comedidev.h" #include "comedi_internal.h" struct comedi_driver *comedi_drivers; /* protects access to comedi_drivers */ DEFINE_MUTEX(comedi_drivers_list_lock); /** * comedi_set_hw_dev() - Set hardware device associated with COMEDI device * @dev: COMEDI device. * @hw_dev: Hardware device. * * For automatically configured COMEDI devices (resulting from a call to * comedi_auto_config() or one of its wrappers from the low-level COMEDI * driver), comedi_set_hw_dev() is called automatically by the COMEDI core * to associate the COMEDI device with the hardware device. It can also be * called directly by "legacy" low-level COMEDI drivers that rely on the * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware * has a &struct device. * * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times * with the same hardware device is not considered an error. If it gets * a reference to the hardware device, it will be automatically 'put' when * the device is detached from COMEDI. * * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise * returns -EEXIST. */ 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) 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. * @size: Size of the memory to allocate. * * The allocated memory is zero-filled. @dev->private points to it on * return. The memory will be automatically freed when the COMEDI device is * "detached". * * Returns a pointer to the allocated memory, or NULL on failure. */ 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); /** * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device * @dev: COMEDI device. * @num_subdevices: Number of subdevices to allocate. * * Allocates and initializes an array of &struct comedi_subdevice for the * COMEDI device. If successful, sets @dev->subdevices to point to the * first one and @dev->n_subdevices to the number. * * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if * failed to allocate the memory. */ 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); /** * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback * @s: COMEDI subdevice. * * This is called by low-level COMEDI drivers to allocate an array to record * the last values written to a subdevice's analog output channels (at least * by the %INSN_WRITE instruction), to allow them to be read back by an * %INSN_READ instruction. It also provides a default handler for the * %INSN_READ instruction unless one has already been set. * * On success, @s->readback points to the first element of the array, which * is zero-filled. The low-level driver is responsible for updating its * contents. @s->insn_read will be set to comedi_readback_insn_read() * unless it is already non-NULL. * * Returns 0 on success, -EINVAL if the subdevice has no channels, or * -ENOMEM on allocation failure. */ int comedi_alloc_subdev_readback(struct comedi_subdevice *s) { if (!s->n_chan) return -EINVAL; s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL); if (!s->readback) return -ENOMEM; if (!s->insn_read) s->insn_read = comedi_readback_insn_read; return 0; } EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback); static void comedi_device_detach_cleanup(struct comedi_device *dev) { int i; struct comedi_subdevice *s; lockdep_assert_held(&dev->attach_lock); lockdep_assert_held(&dev->mutex); if (dev->subdevices) { for (i = 0; i < dev->n_subdevices; i++) { s = &dev->subdevices[i]; if (comedi_can_auto_free_spriv(s)) kfree(s->private); comedi_free_subdevice_minor(s); if (s->async) { comedi_buf_alloc(dev, s, 0); kfree(s->async); } kfree(s->readback); } kfree(dev->subdevices); dev->subdevices = NULL; dev->n_subdevices = 0; } kfree(dev->private); kfree(dev->pacer); dev->private = NULL; dev->pacer = NULL; dev->driver = NULL; dev->board_name = NULL; dev->board_ptr = NULL; dev->mmio = 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) { lockdep_assert_held(&dev->mutex); 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; } static int insn_device_inval(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { return -EINVAL; } static unsigned int get_zero_valid_routes(struct comedi_device *dev, unsigned int n_pairs, unsigned int *pair_data) { return 0; } int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { return -EINVAL; } /** * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback. * @dev: COMEDI device. * @s: COMEDI subdevice. * @insn: COMEDI instruction. * @data: Pointer to return the readback data. * * Handles the %INSN_READ instruction for subdevices that use the readback * array allocated by comedi_alloc_subdev_readback(). It may be used * directly as the subdevice's handler (@s->insn_read) or called via a * wrapper. * * @insn->n is normally 1, which will read a single value. If higher, the * same element of the readback array will be read multiple times. * * Returns @insn->n on success, or -EINVAL if @s->readback is NULL. */ int comedi_readback_insn_read(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { unsigned int chan = CR_CHAN(insn->chanspec); int i; if (!s->readback) return -EINVAL; for (i = 0; i < insn->n; i++) data[i] = s->readback[chan]; return insn->n; } EXPORT_SYMBOL_GPL(comedi_readback_insn_read); /** * comedi_timeout() - Busy-wait for a driver condition to occur * @dev: COMEDI device. * @s: COMEDI subdevice. * @insn: COMEDI instruction. * @cb: Callback to check for the condition. * @context: Private context from the driver. * * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn, * and @context are passed to the callback function, which returns -EBUSY to * continue waiting or some other value to stop waiting (generally 0 if the * condition occurred, or some error value). * * Returns -ETIMEDOUT if timed out, otherwise the return value from the * callback function. */ int comedi_timeout(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, int (*cb)(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned long context), unsigned long context) { unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS); int ret; while (time_before(jiffies, timeout)) { ret = cb(dev, s, insn, context); if (ret != -EBUSY) return ret; /* success (0) or non EBUSY errno */ cpu_relax(); } return -ETIMEDOUT; } EXPORT_SYMBOL_GPL(comedi_timeout); /** * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices * @dev: COMEDI device. * @s: COMEDI subdevice. * @insn: COMEDI instruction. * @data: Instruction parameters and return data. * @mask: io_bits mask for grouped channels, or 0 for single channel. * * If @mask is 0, it is replaced with a single-bit mask corresponding to the * channel number specified by @insn->chanspec. Otherwise, @mask * corresponds to a group of channels (which should include the specified * channel) that are always configured together as inputs or outputs. * * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS, * and %INSN_CONFIG_DIO_QUERY instructions. The first two update * @s->io_bits to record the directions of the masked channels. The last * one sets @data[1] to the current direction of the group of channels * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits. * * The caller is responsible for updating the DIO direction in the hardware * registers if this function returns 0. * * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or * -EINVAL for some other instruction. */ 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. * @data: The channel mask and bits to update. * * Updates @s->state which holds the internal state of the outputs for DIO * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of * the channels to be updated. @data[1] contains a bit-mask of those * channels to be set to '1'. The caller is responsible for updating the * outputs in hardware according to @s->state. As a minimum, the channels * in the returned bit-mask need to be updated. * * Returns @mask with non-existent channels removed. */ 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); /** * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in * bytes * @s: COMEDI subdevice. * @cmd: COMEDI command. * * Determines the overall scan length according to the subdevice type and the * number of channels in the scan for the specified command. * * For digital input, output or input/output subdevices, samples for * multiple channels are assumed to be packed into one or more unsigned * short or unsigned int values according to the subdevice's %SDF_LSAMPL * flag. For other types of subdevice, samples are assumed to occupy a * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. * * Returns the overall scan length in bytes. */ unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s, struct comedi_cmd *cmd) { unsigned int num_samples; unsigned int bits_per_sample; switch (s->type) { case COMEDI_SUBD_DI: case COMEDI_SUBD_DO: case COMEDI_SUBD_DIO: bits_per_sample = 8 * comedi_bytes_per_sample(s); num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample); break; default: num_samples = cmd->scan_end_arg; break; } return comedi_samples_to_bytes(s, num_samples); } EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd); /** * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes * @s: COMEDI subdevice. * * Determines the overall scan length according to the subdevice type and the * number of channels in the scan for the current command. * * For digital input, output or input/output subdevices, samples for * multiple channels are assumed to be packed into one or more unsigned * short or unsigned int values according to the subdevice's %SDF_LSAMPL * flag. For other types of subdevice, samples are assumed to occupy a * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. * * Returns the overall scan length in bytes. */ unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s) { struct comedi_cmd *cmd = &s->async->cmd; return comedi_bytes_per_scan_cmd(s, cmd); } EXPORT_SYMBOL_GPL(comedi_bytes_per_scan); static unsigned int __comedi_nscans_left(struct comedi_subdevice *s, unsigned int nscans) { struct comedi_async *async = s->async; struct comedi_cmd *cmd = &async->cmd; if (cmd->stop_src == TRIG_COUNT) { unsigned int scans_left = 0; if (async->scans_done < cmd->stop_arg) scans_left = cmd->stop_arg - async->scans_done; if (nscans > scans_left) nscans = scans_left; } return nscans; } /** * comedi_nscans_left() - Return the number of scans left in the command * @s: COMEDI subdevice. * @nscans: The expected number of scans or 0 for all available scans. * * If @nscans is 0, it is set to the number of scans available in the * async buffer. * * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be * checked against the number of scans remaining to complete the command. * * The return value will then be either the expected number of scans or the * number of scans remaining to complete the command, whichever is fewer. */ unsigned int comedi_nscans_left(struct comedi_subdevice *s, unsigned int nscans) { if (nscans == 0) { unsigned int nbytes = comedi_buf_read_n_available(s); nscans = nbytes / comedi_bytes_per_scan(s); } return __comedi_nscans_left(s, nscans); } EXPORT_SYMBOL_GPL(comedi_nscans_left); /** * comedi_nsamples_left() - Return the number of samples left in the command * @s: COMEDI subdevice. * @nsamples: The expected number of samples. * * Returns the number of samples remaining to complete the command, or the * specified expected number of samples (@nsamples), whichever is fewer. */ unsigned int comedi_nsamples_left(struct comedi_subdevice *s, unsigned int nsamples) { struct comedi_async *async = s->async; struct comedi_cmd *cmd = &async->cmd; unsigned long long scans_left; unsigned long long samples_left; if (cmd->stop_src != TRIG_COUNT) return nsamples; scans_left = __comedi_nscans_left(s, cmd->stop_arg); if (!scans_left) return 0; samples_left = scans_left * cmd->scan_end_arg - comedi_bytes_to_samples(s, async->scan_progress); if (samples_left < nsamples) return samples_left; return nsamples; } EXPORT_SYMBOL_GPL(comedi_nsamples_left); /** * comedi_inc_scan_progress() - Update scan progress in asynchronous command * @s: COMEDI subdevice. * @num_bytes: Amount of data in bytes to increment scan progress. * * Increments the scan progress by the number of bytes specified by @num_bytes. * If the scan progress reaches or exceeds the scan length in bytes, reduce * it modulo the scan length in bytes and set the "end of scan" asynchronous * event flag (%COMEDI_CB_EOS) to be processed later. */ void comedi_inc_scan_progress(struct comedi_subdevice *s, unsigned int num_bytes) { struct comedi_async *async = s->async; struct comedi_cmd *cmd = &async->cmd; unsigned int scan_length = comedi_bytes_per_scan(s); /* track the 'cur_chan' for non-SDF_PACKED subdevices */ if (!(s->subdev_flags & SDF_PACKED)) { async->cur_chan += comedi_bytes_to_samples(s, num_bytes); async->cur_chan %= cmd->chanlist_len; } async->scan_progress += num_bytes; if (async->scan_progress >= scan_length) { unsigned int nscans = async->scan_progress / scan_length; if (async->scans_done < (UINT_MAX - nscans)) async->scans_done += nscans; else async->scans_done = UINT_MAX; async->scan_progress %= scan_length; async->events |= COMEDI_CB_EOS; } } EXPORT_SYMBOL_GPL(comedi_inc_scan_progress); /** * comedi_handle_events() - Handle events and possibly stop acquisition * @dev: COMEDI device. * @s: COMEDI subdevice. * * Handles outstanding asynchronous acquisition event flags associated * with the subdevice. Call the subdevice's @s->cancel() handler if the * "end of acquisition", "error" or "overflow" event flags are set in order * to stop the acquisition at the driver level. * * Calls comedi_event() to further process the event flags, which may mark * the asynchronous command as no longer running, possibly terminated with * an error, and may wake up tasks. * * Return a bit-mask of the handled events. */ unsigned int comedi_handle_events(struct comedi_device *dev, struct comedi_subdevice *s) { unsigned int events = s->async->events; if (events == 0) return events; if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel) s->cancel(dev, s); comedi_event(dev, s); return events; } EXPORT_SYMBOL_GPL(comedi_handle_events); static int insn_rw_emulate_bits(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { struct comedi_insn _insn; unsigned int chan = CR_CHAN(insn->chanspec); unsigned int base_chan = (chan < 32) ? 0 : chan; unsigned int _data[2]; int ret; memset(_data, 0, sizeof(_data)); memset(&_insn, 0, sizeof(_insn)); _insn.insn = INSN_BITS; _insn.chanspec = base_chan; _insn.n = 2; _insn.subdev = insn->subdev; if (insn->insn == INSN_WRITE) { if (!(s->subdev_flags & SDF_WRITABLE)) return -EINVAL; _data[0] = 1 << (chan - base_chan); /* mask */ _data[1] = data[0] ? (1 << (chan - base_chan)) : 0; /* bits */ } ret = s->insn_bits(dev, s, &_insn, _data); if (ret < 0) return ret; if (insn->insn == INSN_READ) data[0] = (_data[1] >> (chan - base_chan)) & 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; lockdep_assert_held(&dev->mutex); 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; } if (!s->cancel) dev_warn(dev->class_dev, "async subdevices should have a cancel() function\n"); async = kzalloc(sizeof(*async), GFP_KERNEL); if (!async) return -ENOMEM; init_waitqueue_head(&async->wait_head); 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); 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; lockdep_assert_held(&dev->mutex); if (!dev->insn_device_config) dev->insn_device_config = insn_device_inval; if (!dev->get_valid_routes) dev->get_valid_routes = get_zero_valid_routes; 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; lockdep_assert_held(&dev->mutex); 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. * @device: Hardware device. * @name: The name of the firmware image. * @cb: Callback to the upload the firmware image. * @context: Private context from the driver. * * Sends a firmware request for the hardware device and waits for it. Calls * the callback function to upload the firmware to the device, them releases * the firmware. * * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number * from the firmware request or the callback function. */ 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 region for a legacy driver * @dev: COMEDI device. * @start: Base address of the I/O region. * @len: Length of the I/O region. * * Requests the specified I/O port region which must start at a non-zero * address. * * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request * fails. */ 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 region for a legacy driver * @dev: COMEDI device. * @start: Base address of the I/O region. * @len: Length of the I/O region. * * Requests the specified I/O port region which must start at a non-zero * address. * * On success, @dev->iobase is set to the base address of the region and * @dev->iolen is set to its length. * * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request * fails. */ 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. * * This is a simple, generic 'detach' handler for legacy COMEDI devices that * just use a single I/O port region and possibly an IRQ and that don't need * any special clean-up for their private device or subdevice storage. It * can also be called by a driver-specific 'detach' handler. * * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and * @dev->iolen are both non-zero, the I/O port region will be released. */ 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; lockdep_assert_held(&dev->mutex); 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) { /* 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) { /* 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 = -EIO; goto out; } 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; } /** * comedi_auto_config() - Create a COMEDI device for a hardware device * @hardware_device: Hardware device. * @driver: COMEDI low-level driver for the hardware device. * @context: Driver context for the auto_attach handler. * * Allocates a new COMEDI device for the hardware device and calls the * low-level driver's 'auto_attach' handler to set-up the hardware and * allocate the COMEDI subdevices. Additional "post-configuration" setting * up is performed on successful return from the 'auto_attach' handler. * If the 'auto_attach' handler fails, the low-level driver's 'detach' * handler will be called as part of the clean-up. * * This is usually called from a wrapper function in a bus-specific COMEDI * module, which in turn is usually called from a bus device 'probe' * function in the low-level driver. * * Returns 0 on success, -EINVAL if the parameters are invalid or the * post-configuration determines the driver has set the COMEDI device up * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of * COMEDI minor device numbers, or some negative error number returned by * the driver's 'auto_attach' handler. */ 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! %s called with NULL hardware_device\n", __func__); return -EINVAL; } if (!driver) { dev_warn(hardware_device, "BUG! %s called with NULL comedi driver\n", __func__); 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. */ lockdep_assert_held(&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) { dev_warn(hardware_device, "driver '%s' failed to auto-configure device.\n", driver->driver_name); mutex_unlock(&dev->mutex); 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); mutex_unlock(&dev->mutex); } return ret; } EXPORT_SYMBOL_GPL(comedi_auto_config); /** * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device * @hardware_device: Hardware device previously passed to * comedi_auto_config(). * * Cleans up and eventually destroys the COMEDI device allocated by * comedi_auto_config() for the same hardware device. As part of this * clean-up, the low-level COMEDI driver's 'detach' handler will be called. * (The COMEDI device itself will persist in an unattached state if it is * still open, until it is released, and any mmapped buffers will persist * until they are munmapped.) * * This is usually called from a wrapper module in a bus-specific COMEDI * module, which in turn is usually set as the bus device 'remove' function * in the low-level COMEDI driver. */ void comedi_auto_unconfig(struct device *hardware_device) { if (!hardware_device) return; comedi_release_hardware_device(hardware_device); } EXPORT_SYMBOL_GPL(comedi_auto_unconfig); /** * comedi_driver_register() - Register a low-level COMEDI driver * @driver: Low-level COMEDI driver. * * The low-level COMEDI driver is added to the list of registered COMEDI * drivers. This is used by the handler for the "/proc/comedi" file and is * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure * "legacy" COMEDI devices (for those low-level drivers that support it). * * Returns 0. */ 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); /** * comedi_driver_unregister() - Unregister a low-level COMEDI driver * @driver: Low-level COMEDI driver. * * The low-level COMEDI driver is removed from the list of registered COMEDI * drivers. Detaches any COMEDI devices attached to the driver, which will * result in the low-level driver's 'detach' handler being called for those * devices before this function returns. */ 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);