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path: root/drivers/staging/comedi/comedi_fops.c
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2013-05-13staging: comedi: allow buffer resize if previous resize failedIan Abbott
When a comedi device is successfully attached, those subdevices that support asynchronous commands will have had buffers allocated successfully. It is possible to resize the buffers afterwards, but if the resize fails the subdevice is left with no buffer (`s->async->prealloc_buf == NULL`). Currently, this also causes any subsequent attempts to resize the buffer to fail with an error, which seems like a bad idea. Remove the check in `resize_async_buffer()` that causes the resize to fail if the subdevice currently has no buffer (presumably due to the failure of a previous resize attempt). Callers of `resize_async_buffer()` have already checked that the subdevice is allowed to have a buffer. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-12staging: comedi: use EXPORT_SYMBOL_GPL() for all exported symbolsH Hartley Sweeten
Comedi is licensed under GPL. Some if its exports are currently EXPORT_SYMBOL() and others are EXPORT_SYMBOL_GPL(). Change them all to EXPORT_SYMBOL_GPL() and see if anyone reports any fall out. If any of the symbols "need" to be EXPORT_SYMBOL() they will be addressed as needed. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: add comedi_clear_board_dev()Ian Abbott
Add local function `comedi_clear_board_dev()` as a safer alternative to `comedi_clear_board_minor()` when we already have a pointer to a `struct comedi_device`. It uses the board minor device number stored in the `struct comedi_device` (which must have already been initialized) and only clears the entry in `comedi_board_minor_table[]` if it points to the specified `struct comedi_device`. Rather than returning the old table entry, it returns `true` if the entry matched (and so has just been cleared) and returns `false` otherwise. Call `comedi_clear_board_dev()` instead of `comedi_clear_board_minor()` in `comedi_unlocked_ioctl()` (in the code that frees a dynamically allocated comedi device detached by the `COMEDI_DEVCONFIG` ioctl). That ought to return `true` but check it just in case before freeing the device. There is still a race condition here which needs to be dealt with once we've implemented reference counting for `struct comedi_device`s. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove struct comedi_file_infoIan Abbott
`struct comedi_file_info` is no longer used so remove it. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: simplify comedi_board_minor_table[]Ian Abbott
`comedi_alloc_board_minor()` allocates and initializes a `struct comedi_file_info` and a `struct comedi_device`, and assigns a board minor device number (if there are any available), storing a pointer to the allocated `struct comedi_file_info` in `comedi_board_minor_table[minor]` where `minor` is the board minor device number. There is no longer anything useful in the `struct comedi_file_info` apart from the pointer to the `struct comedi_device` that was allocated, so the `struct comedi_file_info` is superfluous. Change `comedi_board_minor_table[]` to hold pointers to the actual `struct comedi_device`'s. `comedi_alloc_board_minor()` no longer needs to allocate a `struct comedi_file_info`. Replace `comedi_free_board_file_info()` with `comedi_free_board_dev()` with its parameter pointing to the `struct comedi_device` to be freed (there is no longer a `struct comedi_file_info` to be freed). There are consequential changes to `comedi_dev_from_board_minor()`, `comedi_clear_board_minor()` (which now returns a `struct comedi_device *`), `comedi_free_board_minor()`, `comedi_release_hardware_device()` and `comedi_unlocked_ioctl()` (when dealing with detachment of a dynamically allocated comedi device by the `COMEDI_DEVCONFIG` ioctl). `comedi_dev_from_file_info()` is no longer used as a result of the above changes so remove it. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: simplify comedi_subdevice_minor_table[]Ian Abbott
`comedi_alloc_subdevice_minor()` allocates and initializes a `struct comedi_file_info` and assigns a subdevice minor device number (if there are any available), storing a pointer to the allocated `struct comedi_file_info` in `comedi_subdevice_minor_table[i]` where `i` is the array index corresponding to the subdevice minor device number (indexed by subdevice minor device number minus `COMEDI_NUM_BOARD_MINORS`). The information stored in the `struct comedi_file_info` can be derived from the subdevice structure (`struct comedi_subdevice`) itself, so the `struct comedi_file_info` is superfluous. Change `comedi_subdevice_minor_table[]` to hold pointers to the actual `struct comedi_subdevice`'s. `comedi_alloc_subdevice_minor()` no longer needs to allocate a `struct comedi_file_info` and `comedi_free_subdevice_info()` no longer has a `struct comedi_file_info` to free. Replace `comedi_file_info_from_minor()` with `comedi_subdevice_from_minor()`, returning a (possibly NULL) pointer to a `struct comedi_subdevice` from the table. This has knock-on effects for `comedi_dev_from_subdevice_minor()`, `comedi_read_subdevice()` and `comedi_write_subdevice()`. In particular, `comedi_read_subdevice()` and `comedi_write_subdevice()` now need to check the subdevice flags to see if the determine whether to override the comedi device's default read/write subdevice. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove comedi_file_info_from_board_minor()Ian Abbott
Merge the code from `comedi_file_info_from_board_minor()` into `comedi_dev_from_board_minor()` and remove it since nothing else calls it. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove comedi_clear_subdevice_minor()Ian Abbott
Merge the code from `comedi_clear_subdevice_minor()` into `comedi_free_subdevice_minor()` and remove it since nothing else calls it. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: refactor comedi_dev_from_minor()Ian Abbott
Refactor `comedi_dev_from_minor()` to call one of two new functions `comedi_dev_from_board_minor()` (for minor device numbers less than `COMEDI_NUM_BOARD_MINORS`) or `comedi_dev_from_subdevice_minor()` (for minor device numbers greater than or equal to `COMEDI_NUM_BOARD_MINORS`, which are subdevice minor device numbers). Remove `comedi_file_info_from_minor()` as it is no longer used. This is a step towards removing `struct comedi_file_info`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: reduce use of struct comedi_file_infoIan Abbott
Since the parameters of `comedi_read_subdevice()` and `comedi_write_subdevice()` have changed, there is no longer a need to keep a local variable `struct comedi_file_info *info` hanging around in the file operation functions and device attribute access functions. Remove the variable from those function and replace the call sequence `info = comedi_file_info_from_minor(minor)`, `dev = comedi_dev_from_file_info(info)` with the simpler `dev = comedi_dev_from_minor(minor)`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: change comedi_read/write_subdevice() parametersIan Abbott
`comedi_read_subdevice()` and `comedi_write_subdevice()` currently take a single parameter pointing to a `struct comedi_file_info`. I'm trying to get rid of `struct comedi_file_info` so as part of that plan, `comedi_read_subdevice()` and `comedi_write_subdevice()` need to change. Change them to take two parameters: a pointer to a `struct comedi_device` and a minor device number. If the minor device number is a "board" minor device number (`minor < COMEDI_NUM_BOARD_MINORS`) we'll always return the default read or write subdevice. If the minor device number if a "subdevice" minor device number a different read or write subdevice may be returned. In that case, use the subdevice minor device number to look up the information about whether the default read or write subdevice needs to be overridden. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: use minor device number in attribute functionsIan Abbott
The comedi device attribute functions such as `show_max_read_buffer_kb()` call `dev_get_drvdata()` to get a pointer to a `struct comedi_file_info` from the private driver data field of class device. Change them to use the minor device number to look up this pointer value so they behave more like the file operation functions. Check the pointer is non-NULL as the entry in the minor device table could have been set to NULL. Note that there is still a race condition in the use of this pointer value after acquiring the mutex which needs to be dealt with once reference counting has been implemented for comedi devices. The calls to `dev_set_drvdata()` from `comedi_alloc_board_minor()` and `comedi_alloc_subdevice_minor()` are no longer needed so remove them. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: get mutex before subdevice in attribute functionsIan Abbott
The comedi device attribute functions such as `show_read_buffer_kb()` or `show_write_buffer_kb()` call `comedi_read_subdevice()` or `comedi_write_subdevice()` without acquiring the comedi device's mutex first, although the functions do acquire the mutex afterwards. Change them to acquire the mutex first. This is consistent with most of the comedi device file operation functions (apart from `comedi_read()` and `comedi_write()` which probably need looking at). Despite the use of the mutex, there are still race conditions as the `struct comedi_file_info *info` variable value set before acquiring the mutex could be stale after acquiring the mutex. This problem will be dealt with once reference counting has been implemented for the comedi devices. This patch also adds local variable `struct comedi_device *dev` to the functions to reduce the use of the `info` variable a little bit. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: rename dev parameter of device attribute functionsIan Abbott
Most of the comedi core uses the identifier `dev` to point to a `struct comedi_device`. The device sysfs attribute functions such as `show_max_read_buffer_kb()` use the parameter id `dev` to point to a `struct device`. Rename the parameter to `csdev` for "class device" for consistency with the functions that call `device_create()` to create these class devices (`comedi_alloc_board_minor()` and `comedi_alloc_subdevice_minor()`). Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove hardware_device from struct comedi_device_infoIan Abbott
The `hardware_device` member of `struct comedi_device_info` is only set to point to a hardware device by the auto-configuration code (specifically `comedi_alloc_board_minor() with a non-NULL `hardware_device` parameter) so that it can be found again by the auto-unconfiguration code (specifically `comedi_release_hardware_device()`). However, as `info->device->hw_dev` (where `info` is a pointer to the `struct comedi_device_info`) is set to the same value as `info->hardware_device` (by calling `comedi_set_hw_dev()` with the same hardware device pointer) we can look for that instead, so there is no need for the `hardware_device` member any more. Get rid of it. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove comedi_clear_minor()Ian Abbott
`comedi_clear_minor()` calls either `comedi_clear_board_minor()` or `comedi_clear_subdevice_minor()` depending on its minor device number parameter. The one it calls only depends on where it is called from, so bypass the calls to `comedi_clear_minor()` and remove it. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: separate board and subdevice minor tablesIan Abbott
The comedi core reserves minor device numbers from 0 to `COMEDI_NUM_BOARD_MINORS - 1` (0 to 0x30 - 1) for the main comedi "board" devices and reserves minor device numbers from `COMEDI_NUM_BOARD_MINORS` to `COMEDI_NUM_MINORS - 1` (0x30 to 0x100 - 1) for comedi subdevices (or at least those that claim to support asynchronous comedi commands). There is an array `comedi_file_info_table[COMEDI_NUM_MINORS]` used to hold pointers to information for each board minor device number and subdevice minor device number that has been allocated (with NULL pointers for those not allocated), along with a protective lock `comedi_file_info_table_lock`. Since the ranges of board minor device numbers and subdevice minor device numbers do not overlap, we can use separate tables and separate locks for the different types of minor device numbers. This will allow us to use different pointer types for the elements of each table in the future without just using a generic `void *`. (At the moment, the table elements point to a `struct comedi_file_info` allocated dynamically for each allocated board minor device or subdevice minor device, but I plan to get rid of that data structure.) Replace `comedi_file_info_table[COMEDI_NUM_MINORS]` with two new arrays of the same type, `comedi_board_minor_table[COMEDI_NUM_BOARD_MINORS]` for board minors, and `comedi_subdevice_minor_table[COMEDI_NUM_SUBDEVICE_MINORS]` for subdevice minors (where `COMEDI_NUM_SUBDEVICE_MINORS` is `COMEDI_NUM_MINORS - COMEDI_NUM_BOARD_MINORS`). `comedi_subdevice_minor_table[]` is indexed by the subdevice minor number minus `COMEDI_NUM_BOARD_MINORS` since `COMEDI_NUM_BOARD_MINORS` is the first valid subdevice minor number. Replace `comedi_file_info_table_lock` with `comedi_board_minor_table_lock` for board minors and `comedi_subdevice_minor_table_lock` for subdevice minors. Refactor `comedi_clear_minor()` to call one of two new functions `comedi_clear_board_minor()` and `comedi_clear_subdevice_minor()` depending on the minor device number passed as a parameter. Similarly, refactor `comedi_file_info_from_minor()` to call one of two new functions `comedi_file_info_from_board_minor()` and `comedi_file_info_from_subdevice_minor()` depending on the minor device number parameter. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove COMEDI_FIRST_SUBDEVICE_MINORIan Abbott
The macro `COMEDI_FIRST_SUBDEVICE_MINOR` just expands to another macro `COMEDI_NUM_BOARD_MINORS`. Replace uses of `COMEDI_FIRST_SUBDEVICE_MINOR` with `COMEDI_NUM_BOARD_MINORS` and get rid of the former. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: move COMEDI_NUM_MINORS and COMEDI_FIRST_SUBDEVICE_MINORIan Abbott
The macro definitions `COMEDI_NUM_MINORS` and `COMEDI_FIRST_SUBDEVICE_MINOR` are only used in "comedi_fops.c" so move them to there from "comedidev.h". Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: change comedi_file_info_table_lock to mutexIan Abbott
The spin-lock `comedi_file_info_table_lock` is used to protect against simultaneous modification and access of `comedi_file_info_table[]`. Change it from a spin-lock to a mutex as it is only used in contexts where sleeping is allowed. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: set hw_dev in comedi_alloc_board_minor()Ian Abbott
Call `comedi_set_hw_dev()` to set the `hw_dev` member of `struct comedi_device` in `comedi_alloc_board_minor()` instead of in `comedi_auto_config()`. Don't bother to check for an error returned by `comedi_set_hw_dev()` here; it only fails when changing a non-NULL pointer to a different non-NULL pointer and since the `struct comedi_device` has just been allocated and initialized, its `hw_dev` will be NULL already. Calling `comedi_set_hw_dev()` with a non-NULL hardware device pointer increments the kref counter for the hardware device. If `comedi_alloc_board_minor()` fails further down the function, we rely on its call to `comedi_device_cleanup()` to call `comedi_clear_hw_dev()` (via `comedi_device_detach()` and `cleanup_device()`) to clear `hw_dev` and decrement its kref counter. (That's the "beneficial side-effect" mentioned in the patch that replaced `__comedi_device_detach()`.) Remove the call to `comedi_set_hw_dev()` from `comedi_auto_config()` as the call to `comedi_alloc_board_minor()` does it for us. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: simplify driver module countingIan Abbott
For a legacy device attachment with the `COMEDI_DEVCONFIG` ioctl, `do_devconfig_ioctl()` calls `comedi_device_attach()` to find a matching device driver and attach the device. It then tries to increment the device driver's module count and if that fails it detaches the device. So on successful attachment of a device by the `COMEDI_DEVCONFIG` ioctl, the device driver's module count will have been incremented. `comedi_device_attach()` is called from nowhere else. It already increments the device driver's module count temporarily and decrements it again; if it gets as far as calling `comedi_device_postconfig()` the module count is decremented within that function. Simplify the above by removing the decrement of the device driver module count from `comedi_device_postconfig()`. If the call to `comedi_device_postconfig()` succeeds, `comedi_device_attach()` will return with the module count still incremented, otherwise decrement the module count before returning the error. Don't try and increment the module count in `do_devconfig_ioctl()` after a successful return from `comedi_device_attach()` as the module count has now already been incremented. `comedi_device_postconfig()` is also called by `comedi_auto_config()` which currently has to increment the device driver's module count temporarily so that `comedi_device_postconfig()` can decrement it, but always returns with no overall change to the module count. Remove all the module count manipulations from `comedi_device_postconfig()`. There is no other reason for `comedi_auto_config()` to increment the device driver's module count temporarily, since it is only called (indirectly) from the device driver itself (usually via one of the wrappers `comedi_pci_auto_config()` or `comedi_usb_auto_config()`). Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: avoid forward declarationsIan Abbott
Move a few functions and variables to avoid a couple of forward declarations. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove manually unconfigured dynamic devicesIan Abbott
If a dynamically allocated (non-legacy, and automatically configured) comedi device has been successfully unconfigured by use of the `COMEDI_DEVCONFIG` ioctl, then remove the device afterwards. (Dynamically identified comedi devices are identified by their minor device number being `comedi_num_legacy_minors` or greater.) This is done in `comedi_unlocked_ioctl()` on return from `do_devconfig_ioctl()`. Note that there is an unlikely race condition with some other thread that has just called `comedi_file_info_from_minor()` or `comedi_dev_from_minor()` and is about to use the device, but that race condition also exists for automatically removed devices and will be dealt with properly once reference counting of comedi devices has been implemented. We do avoid a race condition between automatic removal and removal by the `COMEDI_DEVCONFIG` ioctl though. Also add an extra precaution in `do_devconfig_ioctl()` to avoid configuring a dynamically allocated device since there is a tight window avoiding the race condition where this could happen and the device is about to be removed anyway. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: no need to evade comedi_auto_unconfig()Ian Abbott
When `comedi_unlocked_ioctl()` handled the `COMEDI_DEVCONFIG` ioctl via a call to `do_devconfig()`, this used to be allowed to attach a legacy hardware device to any board minor device, and the auto-unconfiguration code for non-legacy used to search all board minor devices to find the hardware device being removed. After calling `do_devconfig()` successfully, `comedi_unlocked_ioctl()` sets the `hardware_device` member of the `struct comedi_file_info` to NULL to stop the auto-unconfiguration code finding it by accident and unconfiguring the wrong comedi device as a result. The above is no longer necessary because `do_devconfig()` now only allows legacy hardware devices to be attached to comedi board minor device numbers below `comedi_num_legacy_minors` and the auto-unconfiguration code (particularly `comedi_release_hardware_device()`) only searches comedi board minor device numbers greater than or equal to `comedi_num_legacy_minors`, so there is no overlap. Remove the now unnecessary setting of `info->hardware_device = NULL` in `comedi_unlocked_ioctl()`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: avoid releasing legacy minors automaticallyIan Abbott
`comedi_alloc_board_minor()` is called for both reserved "legacy" devices created during module initialization, and for dynamically created devices (via `comedi_auto_config()`). All the minor device numbers from 0 to `comedi_num_legacy_minors - 1` are for legacy devices and all those from `comedi_num_legacy_minors` to `COMEDI_NUM_BOARD_MINORS - 1` are for dynamically created devices. `comedi_release_hardware_device()` is called (via `comedi_auto_unconfig()`) when a dynamically created device is being removed. It needs to search the table of minor device numbers to see which one is associated with the hardware device. It currently starts the search at minor device number 0. Change it to start from `comedi_num_legacy_minors` to skip over those belonging to legacy devices. Also change `comedi_alloc_board_minor()` to skip the legacy devices when searching for a free minor device number for the dynamically created device. (The validity of the `hardware_device` parameter is used to distinguish the legacy devices from the dynamically created ones.) Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: pre-lock mutex on creation of comedi deviceIan Abbott
Return from `comedi_alloc_board_minor()` with the mutex of the created `struct comedi_device` pre-locked. This allows further initialization by the caller without the worry of something getting in there first. `comedi_auto_config()` no longer needs to check if the device is already "attached" since whatever was trying to attach the device would need to have locked the mutex first. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: change comedi_alloc_board_minor() to return pointerIan Abbott
Change `comedi_alloc_board_minor()` to return a pointer to the allocated `struct comedi_device` instead of a minor device number. Return an `ERR_PTR()` value on error instead of a negative error number. This saves a call to `comedi_dev_from_minor()` in `comedi_auto_config()`. Also change it to use a local variable `dev` to hold the pointer to the `struct comedi_device` instead of using `info->device` all the time. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: make comedi_free_board_minor() staticIan Abbott
`comedi_free_board_minor()` is now only called from the same .c file it is defined in, so give it static linkage. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: add comedi_release_hardware_device()Ian Abbott
Add `comedi_release_hardware_device()` as a replacement for the call sequence `comedi_find_board_minor()`, `comedi_free_board_minor()`. This is slightly safer as we can make sure nothing funny happens to the found `comedi_file_info_table[]` entry in the middle of the sequence. Change `comedi_auto_unconfig()` to call the new function instead of the old sequence. Remove `comedi_find_board_minor()` as it has no other callers. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: refactor comedi_free_board_minor()Ian Abbott
Split out the part of `comedi_free_board_minor()` that clears the `comedi_file_info_table[]` element into new function `comedi_clear_minor()`. Split out the remainder of the original function into new function `comedi_free_board_file_info()`. Also re-use a call to `comedi_clear_minor()` in `comedi_free_subdevice_minor()` instead of doing the same thing inline. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: adjust module count on device cleanupIan Abbott
`comedi_device_cleanup()` is called just before freeing a comedi device. It is possible for the device to still be open in which case the module reference counts for the core comedi module and possibly the low-level driver module will remain out of whack because `comedi_close()` will not find the comedi device and so will not decrement the module counts. This really needs to be handled better, but for now decrement the module counts in `comedi_device_cleanup()` according to the number of outstanding opens. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: remove memset() call from comedi_device_init()Ian Abbott
`comedi_device_init()` is only called from one place (`comedi_alloc_board_minor()`) and the `struct comedi_device` has already been zeroed out by `kzalloc()`. Don't bother zeroing it out again with `memset()`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05staging: comedi: no need to zero out comedi_file_info_table[]Ian Abbott
In the comedi core module, `comedi_file_info_table[]` is tentatively defined in the .bss section, so will already be zeroed out on initialization. Don't bother zeroing it out again in the module initialization function `comedi_init()`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15staging: comedi: make 'in_request_module' a bool bit-fieldIan Abbott
Change the `in_request_module` member of `struct comedi_device` to a 1-bit bit-field of type `bool` and move it into a suitable hole in the data type to save a few bytes. Change the assigned values to `true` and `false`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-27more file_inode() open-coded instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-07staging: comedi: correct error message in comedi_alloc_subdevice_minor()Ian Abbott
`comedi_alloc_subdevice_minors()` currently prints a message about running out of minor numbers board device files if it runs out of minor device numbers. Change it to complain about running out of minor device numbers for subdevice files as these are in a different range, not shared with those for board device files. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-07staging: comedi: don't return minor from comedi_alloc_subdevice_minor()Ian Abbott
`comedi_alloc_subdevice_minor()` currently returns the allocated minor device number on success. This is not really of any interest to the caller (in fact the return value is not even checked), so just return 0 on success. If the caller really needs to know the allocated minor device number it can look in `s->minor`. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-05staging: comedi: check s->async for poll(), read() and write()Ian Abbott
Some low-level comedi drivers (incorrectly) point `dev->read_subdev` or `dev->write_subdev` to a subdevice that does not support asynchronous commands. Comedi's poll(), read() and write() file operation handlers assume these subdevices do support asynchronous commands. In particular, they assume `s->async` is valid (where `s` points to the read or write subdevice), which it won't be if it has been set incorrectly. This can lead to a NULL pointer dereference. Check `s->async` is non-NULL in `comedi_poll()`, `comedi_read()` and `comedi_write()` to avoid the bug. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-05staging: comedi: remove 'comedi_autoconfig' module parameterH Hartley Sweeten
This module parameter is used to enable the auto config mechanism in the comedi core. Most of the PCI, PCMCIA, and USB drivers have been converted to use the auto config mechanism and will not attach if it is disabled. Since the 'comedi_autoconfig' parameter is defaulted to true, just remove it so that the comedi drivers that use auto config will always be able to attach. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-03staging: comedi: change comedi_alloc_subdevice_minor parametersIan Abbott
`comedi_alloc_subdevice_minor()` doesn't really need a parameter pointing to a `struct comedi_device` as it can get this information from the parameter pointing to a `struct comedi_subdevice`. Just pass the subdevice parameter. Signed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-30staging: comedi: cleanup all board minors on module exitIan Abbott
The comedi core module optionally allocates some legacy board minor devices on module load and cleans these up on module exit. These are used for manual configuration of comedi boards (for those low-level comedi drivers that support manual configuration - mainly for ISA boards). Other board minor devices are created and destroyed dynamically in response to bus device probe and remove requests. The ioctl used for manual configuration (attachment) and removal (detachment) of devices is COMEDI_DEVCONFIG, but that works for any board minor device, including those that were originally created dynamically. If the COMEDI_DEVCONFIG ioctl is used to manually detach an automatically created and attached device, commit 7d3135af399e92cf4c9bbc5f86b6c140aab3b88c ("staging: comedi: prevent auto-unconfig of manually configured devices") ensures that the board minor will no longer be automatically detached and destroyed by a bus device remove request. From that point on the board minor behaves more like one of the comedi "legacy" board minors. (There would be some justification for destroying the board minor instead, but I'd rather leave that decision until removal of board minors has been made safer than it currently is.) Although the board minor behaves more like a legacy board minor, it is not currently cleaned up on module exit. In fact, the module exit code will bug out because this board minor has not been cleaned up. Change comedi_cleanup_legacy_minors() (called from the module exit code, and from the module init code on error) to clean up all board minors. Rename the function to comedi_cleanup_board_minors() to reflect the change in functionality. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-30staging: comedi: disallow COMEDI_DEVCONFIG on non-board minorsIan Abbott
Comedi has two sorts of minor devices: (a) normal board minor devices in the range 0 to COMEDI_NUM_BOARD_MINORS-1 inclusive; and (b) special subdevice minor devices in the range COMEDI_NUM_BOARD_MINORS upwards that are used to open the same underlying comedi device as the normal board minor devices, but with non-default read and write subdevices for asynchronous commands. The special subdevice minor devices get created when a board supporting asynchronous commands is attached to a normal board minor device, and destroyed when the board is detached from the normal board minor device. One way to attach or detach a board is by using the COMEDI_DEVCONFIG ioctl. This should only be used on normal board minors as the special subdevice minors are too ephemeral. In particular, the change introduced in commit 7d3135af399e92cf4c9bbc5f86b6c140aab3b88c ("staging: comedi: prevent auto-unconfig of manually configured devices") breaks horribly for special subdevice minor devices. Since there's no legitimate use for the COMEDI_DEVCONFIG ioctl on a special subdevice minor device node, disallow it and return -ENOTTY. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-29staging: comedi: don't override read/write subdevice if not supportedIan Abbott
For comedi devices that support asynchronous commands on some of their subdevices, the comedi core creates extra device files for each of those subdevices of the form "/dev/comedi%i_subd%i". These use the same comedi device as the corresponding "/dev/comedi%i" but override the default "read" and "write" subdevice for the device. Currently it overrides both the read and write subdevice, but it only makes sense to override the "read" subdevice if the subdevice supports "read" commands, and to override the "write" subdevice if the subdevice supports "write" commands. In `comedi_alloc_subdevice_minor()`, only set `info->read_subdevice` non-NULL if the subdevice has the `SDF_CMD_READ` flag set, and only set `info->write_subdevice` non-NULL if the subdevice has the `SDF_CMD_WRITE` flag set. (`comedi_read_subdevice(info)` will use the device's default read subdevice if `info->read_subdevice` is NULL. `comedi_write_subdevice(info)` will use the device's default write subdevice if `info->write_subdevice` is NULL. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-21staging: comedi: comedi_fops: remove last forward declarationH Hartley Sweeten
There is still a forward declaration in this file for parse_insn(). Remove the need for it by moving do_insnlist_ioctl() down a bit. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-21staging/comedi: Use bool initializationsPeter Huewe
Found with coccicheck. The semantic patch that makes this output is available in scripts/coccinelle/misc/boolinit.cocci. More information about semantic patching is available at http://coccinelle.lip6.fr/ Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17staging: comedi: comedi_buf: rename comedi_reset_async_buf()H Hartley Sweeten
For aesthetic reasons, rename this function to comedi_buf_reset(). This makes all the asynchronous buffer functions have the same namespace. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17staging: comedi: deprecate loading firmware with comedi_configH Hartley Sweeten
All the comedi drivers have been converted to use the request_firmware() hotplug interface. The COMEDI_DEVCONFIG ioctl support for passing the firmware blob as 'aux_data' is no longer required. Remove the feature and give the user a dev_warn message if it is attempted. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17staging: comedi: (core): add comedi_dev_from_file_info()Ian Abbott
Setting `info = comedi_file_info_from_minor(minor)` and `dev = comedi_dev_from_minor(minor)` in the same function is a bit of a waste. The latter function is just a call of the former followed by a conditional return of an embedded pointer (`info->device`) or NULL. The former function uses a spin-lock which is where the wastfulness comes in. Move the "followed by a conditional return of an embedded pointer" part into a new function `comedi_dev_from_file_info` and call this instead of `comedi_dev_from_minor()` in the places where `comedi_file_info_from_minor()` is also called. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-07Merge branch 'staging-linus' into staging-nextGreg Kroah-Hartman
This is to get the comedi fixes, and resolve the issue in comdi_test.c and comedi_fops.c that were caused by changes in both branches. It also allows the fwserial driver changes to be applied, as they required the fixes that are in staging-linus. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>