// 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 <ds@schleef.org> * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net> */ #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_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); if (!IS_ERR(dev->pacer)) 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);Lines 1–500 of 1184. 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// 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 <ds@schleef.org> * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net> */ #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_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); if (!IS_ERR(dev->pacer)) 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);