// 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 <[email protected]> * Copyright (C) 2002 Frank Mori Hess <[email protected]> */ #include <linux/device.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/ioport.h> #include <linux/slab.h> #include <linux/dma-direction.h> #include <linux/interrupt.h> #include <linux/firmware.h> #include <linux/comedi/comedidev.h> #include "comedi_internal.h" struct comedi_driver *comedi_drivers; /* protects access to comedi_drivers */ DEFINE_MUTEX(…) …; /** * 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) { … } EXPORT_SYMBOL_GPL(…); static void comedi_clear_hw_dev(struct comedi_device *dev) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); static void comedi_device_detach_cleanup(struct comedi_device *dev) { … } void comedi_device_detach(struct comedi_device *dev) { … } static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) { … } static int insn_device_inval(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { … } static unsigned int get_zero_valid_routes(struct comedi_device *dev, unsigned int n_pairs, unsigned int *pair_data) { … } int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); static unsigned int __comedi_nscans_left(struct comedi_subdevice *s, unsigned int 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); static int insn_rw_emulate_bits(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { … } static int __comedi_device_postconfig_async(struct comedi_device *dev, struct comedi_subdevice *s) { … } static int __comedi_device_postconfig(struct comedi_device *dev) { … } /* do a little post-config cleanup */ static int comedi_device_postconfig(struct comedi_device *dev) { … } /* * 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) { … } static void comedi_report_boards(struct comedi_driver *driv) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * __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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…);
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