diff options
Diffstat (limited to 'drivers/staging/comedi/comedi_fops.c')
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 467 |
1 files changed, 262 insertions, 205 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index f143cb64d69e..727640e89c73 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1,20 +1,20 @@ /* - comedi/comedi_fops.c - comedi kernel module - - 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. -*/ + * comedi/comedi_fops.c + * comedi kernel module + * + * 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. + */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -113,6 +113,18 @@ static void comedi_dev_kref_release(struct kref *kref) kfree(dev); } +/** + * comedi_dev_put - release a use of a comedi device structure + * @dev: comedi_device struct + * + * Must be called when a user of a comedi device is finished with it. + * When the last user of the comedi device calls this function, the + * comedi device is destroyed. + * + * Return 1 if the comedi device is destroyed by this call or dev is + * NULL, otherwise return 0. Callers must not assume the comedi + * device is still valid if this function returns 0. + */ int comedi_dev_put(struct comedi_device *dev) { if (dev) @@ -220,6 +232,18 @@ static struct comedi_device *comedi_dev_get_from_subdevice_minor(unsigned minor) return dev; } +/** + * comedi_dev_get_from_minor - get comedi device by minor device number + * @minor: minor device number + * + * Finds the comedi device associated by the minor device number, if any, + * and increments its reference count. The comedi device is prevented from + * being freed until a matching call is made to comedi_dev_put(). + * + * Return a pointer to the comedi device if it exists, with its usage + * reference incremented. Return NULL if no comedi device exists with the + * specified minor device number. + */ struct comedi_device *comedi_dev_get_from_minor(unsigned minor) { if (minor < COMEDI_NUM_BOARD_MINORS) @@ -323,8 +347,7 @@ static int resize_async_buffer(struct comedi_device *dev, return -EBUSY; } - /* make sure buffer is an integral number of pages - * (we round up) */ + /* make sure buffer is an integral number of pages (we round up) */ new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK; retval = comedi_buf_alloc(dev, s, new_size); @@ -600,11 +623,18 @@ static unsigned comedi_get_subdevice_runflags(struct comedi_subdevice *s) return runflags; } +/** + * comedi_is_subdevice_running - check if async command running on subdevice + * @s: comedi_subdevice struct + * + * Return true if an asynchronous comedi command is active on the comedi + * subdevice, else return false. + */ bool comedi_is_subdevice_running(struct comedi_subdevice *s) { unsigned runflags = comedi_get_subdevice_runflags(s); - return (runflags & SRF_RUNNING) ? true : false; + return (runflags & COMEDI_SRF_RUNNING) ? true : false; } EXPORT_SYMBOL_GPL(comedi_is_subdevice_running); @@ -612,14 +642,14 @@ static bool comedi_is_subdevice_in_error(struct comedi_subdevice *s) { unsigned runflags = comedi_get_subdevice_runflags(s); - return (runflags & SRF_ERROR) ? true : false; + return (runflags & COMEDI_SRF_ERROR) ? true : false; } static bool comedi_is_subdevice_idle(struct comedi_subdevice *s) { unsigned runflags = comedi_get_subdevice_runflags(s); - return (runflags & (SRF_ERROR | SRF_RUNNING)) ? false : true; + return (runflags & COMEDI_SRF_BUSY_MASK) ? false : true; } /** @@ -634,20 +664,20 @@ void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size) { s->private = kzalloc(size, GFP_KERNEL); if (s->private) - s->runflags |= SRF_FREE_SPRIV; + s->runflags |= COMEDI_SRF_FREE_SPRIV; return s->private; } EXPORT_SYMBOL_GPL(comedi_alloc_spriv); /* - This function restores a subdevice to an idle state. + * This function restores a subdevice to an idle state. */ static void do_become_nonbusy(struct comedi_device *dev, struct comedi_subdevice *s) { struct comedi_async *async = s->async; - comedi_set_subdevice_runflags(s, SRF_RUNNING, 0); + comedi_set_subdevice_runflags(s, COMEDI_SRF_RUNNING, 0); if (async) { comedi_buf_reset(s); async->inttrig = NULL; @@ -709,18 +739,18 @@ static int is_device_busy(struct comedi_device *dev) } /* - COMEDI_DEVCONFIG - device config ioctl - - arg: - pointer to devconfig structure - - reads: - devconfig structure at arg - - writes: - none -*/ + * COMEDI_DEVCONFIG ioctl + * attaches (and configures) or detaches a legacy device + * + * arg: + * pointer to comedi_devconfig structure (NULL if detaching) + * + * reads: + * comedi_devconfig structure (if attaching) + * + * writes: + * nothing + */ static int do_devconfig_ioctl(struct comedi_device *dev, struct comedi_devconfig __user *arg) { @@ -761,19 +791,18 @@ static int do_devconfig_ioctl(struct comedi_device *dev, } /* - COMEDI_BUFCONFIG - buffer configuration ioctl - - arg: - pointer to bufconfig structure - - reads: - bufconfig at arg - - writes: - modified bufconfig at arg - -*/ + * COMEDI_BUFCONFIG ioctl + * buffer configuration + * + * arg: + * pointer to comedi_bufconfig structure + * + * reads: + * comedi_bufconfig structure + * + * writes: + * modified comedi_bufconfig structure + */ static int do_bufconfig_ioctl(struct comedi_device *dev, struct comedi_bufconfig __user *arg) { @@ -823,19 +852,18 @@ copyback: } /* - COMEDI_DEVINFO - device info ioctl - - arg: - pointer to devinfo structure - - reads: - none - - writes: - devinfo structure - -*/ + * COMEDI_DEVINFO ioctl + * device info + * + * arg: + * pointer to comedi_devinfo structure + * + * reads: + * nothing + * + * writes: + * comedi_devinfo structure + */ static int do_devinfo_ioctl(struct comedi_device *dev, struct comedi_devinfo __user *arg, struct file *file) @@ -870,19 +898,18 @@ static int do_devinfo_ioctl(struct comedi_device *dev, } /* - COMEDI_SUBDINFO - subdevice info ioctl - - arg: - pointer to array of subdevice info structures - - reads: - none - - writes: - array of subdevice info structures at arg - -*/ + * COMEDI_SUBDINFO ioctl + * subdevices info + * + * arg: + * pointer to array of comedi_subdinfo structures + * + * reads: + * nothing + * + * writes: + * array of comedi_subdinfo structures + */ static int do_subdinfo_ioctl(struct comedi_device *dev, struct comedi_subdinfo __user *arg, void *file) { @@ -944,19 +971,19 @@ static int do_subdinfo_ioctl(struct comedi_device *dev, } /* - COMEDI_CHANINFO - subdevice info ioctl - - arg: - pointer to chaninfo structure - - reads: - chaninfo structure at arg - - writes: - arrays at elements of chaninfo structure - -*/ + * COMEDI_CHANINFO ioctl + * subdevice channel info + * + * arg: + * pointer to comedi_chaninfo structure + * + * reads: + * comedi_chaninfo structure + * + * writes: + * array of maxdata values to chaninfo->maxdata_list if requested + * array of range table lengths to chaninfo->range_table_list if requested + */ static int do_chaninfo_ioctl(struct comedi_device *dev, struct comedi_chaninfo __user *arg) { @@ -1004,20 +1031,19 @@ static int do_chaninfo_ioctl(struct comedi_device *dev, return 0; } - /* - COMEDI_BUFINFO - buffer information ioctl - - arg: - pointer to bufinfo structure - - reads: - bufinfo at arg - - writes: - modified bufinfo at arg - - */ +/* + * COMEDI_BUFINFO ioctl + * buffer information + * + * arg: + * pointer to comedi_bufinfo structure + * + * reads: + * comedi_bufinfo structure + * + * writes: + * modified comedi_bufinfo structure + */ static int do_bufinfo_ioctl(struct comedi_device *dev, struct comedi_bufinfo __user *arg, void *file) { @@ -1135,8 +1161,10 @@ static int check_insn_config_length(struct comedi_insn *insn, if (insn->n == 6) return 0; break; - /* by default we allow the insn since we don't have checks for - * all possible cases yet */ + /* + * by default we allow the insn since we don't have checks for + * all possible cases yet + */ default: pr_warn("No check for data length of config insn id %i is implemented\n", data[0]); @@ -1287,9 +1315,11 @@ static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn, if (insn->n != 2) { ret = -EINVAL; } else { - /* Most drivers ignore the base channel in + /* + * Most drivers ignore the base channel in * insn->chanspec. Fix this here if - * the subdevice has <= 32 channels. */ + * the subdevice has <= 32 channels. + */ unsigned int orig_mask = data[0]; unsigned int shift = 0; @@ -1326,19 +1356,19 @@ out: } /* - * COMEDI_INSNLIST - * synchronous instructions + * COMEDI_INSNLIST ioctl + * synchronous instruction list * - * arg: - * pointer to sync cmd structure + * arg: + * pointer to comedi_insnlist structure * - * reads: - * sync cmd struct at arg - * instruction list - * data (for writes) + * reads: + * comedi_insnlist structure + * array of comedi_insn structures from insnlist->insns pointer + * data (for writes) from insns[].data pointers * - * writes: - * data (for reads) + * writes: + * data (for reads) to insns[].data pointers */ /* arbitrary limits */ #define MAX_SAMPLES 256 @@ -1415,18 +1445,18 @@ error: } /* - * COMEDI_INSN - * synchronous instructions + * COMEDI_INSN ioctl + * synchronous instruction * - * arg: - * pointer to insn + * arg: + * pointer to comedi_insn structure * - * reads: - * struct comedi_insn struct at arg - * data (for writes) + * reads: + * comedi_insn structure + * data (for writes) from insn->data pointer * - * writes: - * data (for reads) + * writes: + * data (for reads) to insn->data pointer */ static int do_insn_ioctl(struct comedi_device *dev, struct comedi_insn __user *arg, void *file) @@ -1558,6 +1588,20 @@ static int __comedi_get_user_chanlist(struct comedi_device *dev, return 0; } +/* + * COMEDI_CMD ioctl + * asynchronous acquisition command set-up + * + * arg: + * pointer to comedi_cmd structure + * + * reads: + * comedi_cmd structure + * channel/range list from cmd->chanlist pointer + * + * writes: + * possibly modified comedi_cmd structure (when -EAGAIN returned) + */ static int do_cmd_ioctl(struct comedi_device *dev, struct comedi_cmd __user *arg, void *file) { @@ -1634,10 +1678,13 @@ static int do_cmd_ioctl(struct comedi_device *dev, if (async->cmd.flags & CMDF_WAKE_EOS) async->cb_mask |= COMEDI_CB_EOS; - comedi_set_subdevice_runflags(s, SRF_ERROR | SRF_RUNNING, SRF_RUNNING); + comedi_set_subdevice_runflags(s, COMEDI_SRF_BUSY_MASK, + COMEDI_SRF_RUNNING); - /* set s->busy _after_ setting SRF_RUNNING flag to avoid race with - * comedi_read() or comedi_write() */ + /* + * Set s->busy _after_ setting COMEDI_SRF_RUNNING flag to avoid + * race with comedi_read() or comedi_write(). + */ s->busy = file; ret = s->do_cmd(dev, s); if (ret == 0) @@ -1650,20 +1697,19 @@ cleanup: } /* - COMEDI_CMDTEST - command testing ioctl - - arg: - pointer to cmd structure - - reads: - cmd structure at arg - channel/range list - - writes: - modified cmd structure at arg - -*/ + * COMEDI_CMDTEST ioctl + * asynchronous aquisition command testing + * + * arg: + * pointer to comedi_cmd structure + * + * reads: + * comedi_cmd structure + * channel/range list from cmd->chanlist pointer + * + * writes: + * possibly modified comedi_cmd structure + */ static int do_cmdtest_ioctl(struct comedi_device *dev, struct comedi_cmd __user *arg, void *file) { @@ -1706,20 +1752,18 @@ static int do_cmdtest_ioctl(struct comedi_device *dev, } /* - COMEDI_LOCK - lock subdevice - - arg: - subdevice number - - reads: - none - - writes: - none - -*/ - + * COMEDI_LOCK ioctl + * lock subdevice + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ static int do_lock_ioctl(struct comedi_device *dev, unsigned long arg, void *file) { @@ -1742,21 +1786,18 @@ static int do_lock_ioctl(struct comedi_device *dev, unsigned long arg, } /* - COMEDI_UNLOCK - unlock subdevice - - arg: - subdevice number - - reads: - none - - writes: - none - - This function isn't protected by the semaphore, since - we already own the lock. -*/ + * COMEDI_UNLOCK ioctl + * unlock subdevice + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ static int do_unlock_ioctl(struct comedi_device *dev, unsigned long arg, void *file) { @@ -1779,19 +1820,18 @@ static int do_unlock_ioctl(struct comedi_device *dev, unsigned long arg, } /* - COMEDI_CANCEL - cancel acquisition ioctl - - arg: - subdevice number - - reads: - nothing - - writes: - nothing - -*/ + * COMEDI_CANCEL ioctl + * cancel asynchronous acquisition + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ static int do_cancel_ioctl(struct comedi_device *dev, unsigned long arg, void *file) { @@ -1813,19 +1853,18 @@ static int do_cancel_ioctl(struct comedi_device *dev, unsigned long arg, } /* - COMEDI_POLL ioctl - instructs driver to synchronize buffers - - arg: - subdevice number - - reads: - nothing - - writes: - nothing - -*/ + * COMEDI_POLL ioctl + * instructs driver to synchronize buffers + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ static int do_poll_ioctl(struct comedi_device *dev, unsigned long arg, void *file) { @@ -1941,8 +1980,10 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, mutex_lock(&dev->mutex); - /* Device config is special, because it must work on - * an unconfigured device. */ + /* + * Device config is special, because it must work on + * an unconfigured device. + */ if (cmd == COMEDI_DEVCONFIG) { if (minor >= COMEDI_NUM_BOARD_MINORS) { /* Device config not appropriate on non-board minors. */ @@ -1954,8 +1995,10 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, if (rc == 0) { if (arg == 0 && dev->minor >= comedi_num_legacy_minors) { - /* Successfully unconfigured a dynamically - * allocated device. Try and remove it. */ + /* + * Successfully unconfigured a dynamically + * allocated device. Try and remove it. + */ if (comedi_clear_board_dev(dev)) { mutex_unlock(&dev->mutex); comedi_free_board_dev(dev); @@ -2581,6 +2624,17 @@ static const struct file_operations comedi_fops = { .llseek = noop_llseek, }; +/** + * comedi_event - handle events for asynchronous comedi command + * @dev: comedi_device struct + * @s: comedi_subdevice struct associated with dev + * Context: interrupt (usually), s->spin_lock spin-lock not held + * + * If an asynchronous comedi command is active on the subdevice, process + * any COMEDI_CB_... event flags that have been set, usually by an + * interrupt handler. These may change the run state of the asynchronous + * command, wake a task, and/or send a SIGIO signal. + */ void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s) { struct comedi_async *async = s->async; @@ -2591,18 +2645,21 @@ void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s) return; if (s->async->events & COMEDI_CB_CANCEL_MASK) - runflags_mask |= SRF_RUNNING; + runflags_mask |= COMEDI_SRF_RUNNING; /* * Remember if an error event has occurred, so an error * can be returned the next time the user does a read(). */ if (s->async->events & COMEDI_CB_ERROR_MASK) { - runflags_mask |= SRF_ERROR; - runflags |= SRF_ERROR; + runflags_mask |= COMEDI_SRF_ERROR; + runflags |= COMEDI_SRF_ERROR; } if (runflags_mask) { - /*sets SRF_ERROR and SRF_RUNNING together atomically */ + /* + * Sets COMEDI_SRF_ERROR and COMEDI_SRF_RUNNING together + * atomically. + */ comedi_set_subdevice_runflags(s, runflags_mask, runflags); } |