diff options
Diffstat (limited to 'drivers/comedi/drivers.c')
| -rw-r--r-- | drivers/comedi/drivers.c | 1184 |
1 files changed, 1184 insertions, 0 deletions
diff --git a/drivers/comedi/drivers.c b/drivers/comedi/drivers.c new file mode 100644 index 000000000000..750a6ff3c03c --- /dev/null +++ b/drivers/comedi/drivers.c @@ -0,0 +1,1184 @@ +// 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 "comedidev.h" +#include "comedi_internal.h" + +struct comedi_driver *comedi_drivers; +/* protects access to comedi_drivers */ +DEFINE_MUTEX(comedi_drivers_list_lock); + +/** + * comedi_set_hw_dev() - Set hardware device associated with COMEDI device + * @dev: COMEDI device. + * @hw_dev: Hardware device. + * + * For automatically configured COMEDI devices (resulting from a call to + * comedi_auto_config() or one of its wrappers from the low-level COMEDI + * driver), comedi_set_hw_dev() is called automatically by the COMEDI core + * to associate the COMEDI device with the hardware device. It can also be + * called directly by "legacy" low-level COMEDI drivers that rely on the + * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware + * has a &struct device. + * + * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets + * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times + * with the same hardware device is not considered an error. If it gets + * a reference to the hardware device, it will be automatically 'put' when + * the device is detached from COMEDI. + * + * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise + * returns -EEXIST. + */ +int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev) +{ + if (hw_dev == dev->hw_dev) + return 0; + if (dev->hw_dev) + return -EEXIST; + dev->hw_dev = get_device(hw_dev); + return 0; +} +EXPORT_SYMBOL_GPL(comedi_set_hw_dev); + +static void comedi_clear_hw_dev(struct comedi_device *dev) +{ + put_device(dev->hw_dev); + dev->hw_dev = NULL; +} + +/** + * comedi_alloc_devpriv() - Allocate memory for the device private data + * @dev: COMEDI device. + * @size: Size of the memory to allocate. + * + * The allocated memory is zero-filled. @dev->private points to it on + * return. The memory will be automatically freed when the COMEDI device is + * "detached". + * + * Returns a pointer to the allocated memory, or NULL on failure. + */ +void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size) +{ + dev->private = kzalloc(size, GFP_KERNEL); + return dev->private; +} +EXPORT_SYMBOL_GPL(comedi_alloc_devpriv); + +/** + * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device + * @dev: COMEDI device. + * @num_subdevices: Number of subdevices to allocate. + * + * Allocates and initializes an array of &struct comedi_subdevice for the + * COMEDI device. If successful, sets @dev->subdevices to point to the + * first one and @dev->n_subdevices to the number. + * + * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if + * failed to allocate the memory. + */ +int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices) +{ + struct comedi_subdevice *s; + int i; + + if (num_subdevices < 1) + return -EINVAL; + + s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + dev->subdevices = s; + dev->n_subdevices = num_subdevices; + + for (i = 0; i < num_subdevices; ++i) { + s = &dev->subdevices[i]; + s->device = dev; + s->index = i; + s->async_dma_dir = DMA_NONE; + spin_lock_init(&s->spin_lock); + s->minor = -1; + } + return 0; +} +EXPORT_SYMBOL_GPL(comedi_alloc_subdevices); + +/** + * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback + * @s: COMEDI subdevice. + * + * This is called by low-level COMEDI drivers to allocate an array to record + * the last values written to a subdevice's analog output channels (at least + * by the %INSN_WRITE instruction), to allow them to be read back by an + * %INSN_READ instruction. It also provides a default handler for the + * %INSN_READ instruction unless one has already been set. + * + * On success, @s->readback points to the first element of the array, which + * is zero-filled. The low-level driver is responsible for updating its + * contents. @s->insn_read will be set to comedi_readback_insn_read() + * unless it is already non-NULL. + * + * Returns 0 on success, -EINVAL if the subdevice has no channels, or + * -ENOMEM on allocation failure. + */ +int comedi_alloc_subdev_readback(struct comedi_subdevice *s) +{ + if (!s->n_chan) + return -EINVAL; + + s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL); + if (!s->readback) + return -ENOMEM; + + if (!s->insn_read) + s->insn_read = comedi_readback_insn_read; + + return 0; +} +EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback); + +static void comedi_device_detach_cleanup(struct comedi_device *dev) +{ + int i; + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->attach_lock); + lockdep_assert_held(&dev->mutex); + if (dev->subdevices) { + for (i = 0; i < dev->n_subdevices; i++) { + s = &dev->subdevices[i]; + if (comedi_can_auto_free_spriv(s)) + kfree(s->private); + comedi_free_subdevice_minor(s); + if (s->async) { + comedi_buf_alloc(dev, s, 0); + kfree(s->async); + } + kfree(s->readback); + } + kfree(dev->subdevices); + dev->subdevices = NULL; + dev->n_subdevices = 0; + } + kfree(dev->private); + kfree(dev->pacer); + dev->private = NULL; + dev->pacer = NULL; + dev->driver = NULL; + dev->board_name = NULL; + dev->board_ptr = NULL; + dev->mmio = NULL; + dev->iobase = 0; + dev->iolen = 0; + dev->ioenabled = false; + dev->irq = 0; + dev->read_subdev = NULL; + dev->write_subdev = NULL; + dev->open = NULL; + dev->close = NULL; + comedi_clear_hw_dev(dev); +} + +void comedi_device_detach(struct comedi_device *dev) +{ + lockdep_assert_held(&dev->mutex); + comedi_device_cancel_all(dev); + down_write(&dev->attach_lock); + dev->attached = false; + dev->detach_count++; + if (dev->driver) + dev->driver->detach(dev); + comedi_device_detach_cleanup(dev); + up_write(&dev->attach_lock); +} + +static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) +{ + return -EINVAL; +} + +static int insn_device_inval(struct comedi_device *dev, + struct comedi_insn *insn, unsigned int *data) +{ + return -EINVAL; +} + +static unsigned int get_zero_valid_routes(struct comedi_device *dev, + unsigned int n_pairs, + unsigned int *pair_data) +{ + return 0; +} + +int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, + struct comedi_insn *insn, unsigned int *data) +{ + return -EINVAL; +} + +/** + * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback. + * @dev: COMEDI device. + * @s: COMEDI subdevice. + * @insn: COMEDI instruction. + * @data: Pointer to return the readback data. + * + * Handles the %INSN_READ instruction for subdevices that use the readback + * array allocated by comedi_alloc_subdev_readback(). It may be used + * directly as the subdevice's handler (@s->insn_read) or called via a + * wrapper. + * + * @insn->n is normally 1, which will read a single value. If higher, the + * same element of the readback array will be read multiple times. + * + * Returns @insn->n on success, or -EINVAL if @s->readback is NULL. + */ +int comedi_readback_insn_read(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data) +{ + unsigned int chan = CR_CHAN(insn->chanspec); + int i; + + if (!s->readback) + return -EINVAL; + + for (i = 0; i < insn->n; i++) + data[i] = s->readback[chan]; + + return insn->n; +} +EXPORT_SYMBOL_GPL(comedi_readback_insn_read); + +/** + * comedi_timeout() - Busy-wait for a driver condition to occur + * @dev: COMEDI device. + * @s: COMEDI subdevice. + * @insn: COMEDI instruction. + * @cb: Callback to check for the condition. + * @context: Private context from the driver. + * + * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or + * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn, + * and @context are passed to the callback function, which returns -EBUSY to + * continue waiting or some other value to stop waiting (generally 0 if the + * condition occurred, or some error value). + * + * Returns -ETIMEDOUT if timed out, otherwise the return value from the + * callback function. + */ +int comedi_timeout(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + int (*cb)(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned long context), + unsigned long context) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS); + int ret; + + while (time_before(jiffies, timeout)) { + ret = cb(dev, s, insn, context); + if (ret != -EBUSY) + return ret; /* success (0) or non EBUSY errno */ + cpu_relax(); + } + return -ETIMEDOUT; +} +EXPORT_SYMBOL_GPL(comedi_timeout); + +/** + * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices + * @dev: COMEDI device. + * @s: COMEDI subdevice. + * @insn: COMEDI instruction. + * @data: Instruction parameters and return data. + * @mask: io_bits mask for grouped channels, or 0 for single channel. + * + * If @mask is 0, it is replaced with a single-bit mask corresponding to the + * channel number specified by @insn->chanspec. Otherwise, @mask + * corresponds to a group of channels (which should include the specified + * channel) that are always configured together as inputs or outputs. + * + * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS, + * and %INSN_CONFIG_DIO_QUERY instructions. The first two update + * @s->io_bits to record the directions of the masked channels. The last + * one sets @data[1] to the current direction of the group of channels + * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits. + * + * The caller is responsible for updating the DIO direction in the hardware + * registers if this function returns 0. + * + * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT + * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or + * -EINVAL for some other instruction. + */ +int comedi_dio_insn_config(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data, + unsigned int mask) +{ + unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec); + + if (!mask) + mask = chan_mask; + + switch (data[0]) { + case INSN_CONFIG_DIO_INPUT: + s->io_bits &= ~mask; + break; + + case INSN_CONFIG_DIO_OUTPUT: + s->io_bits |= mask; + break; + + case INSN_CONFIG_DIO_QUERY: + data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT; + return insn->n; + + default: + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(comedi_dio_insn_config); + +/** + * comedi_dio_update_state() - Update the internal state of DIO subdevices + * @s: COMEDI subdevice. + * @data: The channel mask and bits to update. + * + * Updates @s->state which holds the internal state of the outputs for DIO + * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of + * the channels to be updated. @data[1] contains a bit-mask of those + * channels to be set to '1'. The caller is responsible for updating the + * outputs in hardware according to @s->state. As a minimum, the channels + * in the returned bit-mask need to be updated. + * + * Returns @mask with non-existent channels removed. + */ +unsigned int comedi_dio_update_state(struct comedi_subdevice *s, + unsigned int *data) +{ + unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1) + : 0xffffffff; + unsigned int mask = data[0] & chanmask; + unsigned int bits = data[1]; + + if (mask) { + s->state &= ~mask; + s->state |= (bits & mask); + } + + return mask; +} +EXPORT_SYMBOL_GPL(comedi_dio_update_state); + +/** + * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in + * bytes + * @s: COMEDI subdevice. + * @cmd: COMEDI command. + * + * Determines the overall scan length according to the subdevice type and the + * number of channels in the scan for the specified command. + * + * For digital input, output or input/output subdevices, samples for + * multiple channels are assumed to be packed into one or more unsigned + * short or unsigned int values according to the subdevice's %SDF_LSAMPL + * flag. For other types of subdevice, samples are assumed to occupy a + * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. + * + * Returns the overall scan length in bytes. + */ +unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s, + struct comedi_cmd *cmd) +{ + unsigned int num_samples; + unsigned int bits_per_sample; + + switch (s->type) { + case COMEDI_SUBD_DI: + case COMEDI_SUBD_DO: + case COMEDI_SUBD_DIO: + bits_per_sample = 8 * comedi_bytes_per_sample(s); + num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample); + break; + default: + num_samples = cmd->scan_end_arg; + break; + } + return comedi_samples_to_bytes(s, num_samples); +} +EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd); + +/** + * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes + * @s: COMEDI subdevice. + * + * Determines the overall scan length according to the subdevice type and the + * number of channels in the scan for the current command. + * + * For digital input, output or input/output subdevices, samples for + * multiple channels are assumed to be packed into one or more unsigned + * short or unsigned int values according to the subdevice's %SDF_LSAMPL + * flag. For other types of subdevice, samples are assumed to occupy a + * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. + * + * Returns the overall scan length in bytes. + */ +unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s) +{ + struct comedi_cmd *cmd = &s->async->cmd; + + return comedi_bytes_per_scan_cmd(s, cmd); +} +EXPORT_SYMBOL_GPL(comedi_bytes_per_scan); + +static unsigned int __comedi_nscans_left(struct comedi_subdevice *s, + unsigned int nscans) +{ + struct comedi_async *async = s->async; + struct comedi_cmd *cmd = &async->cmd; + + if (cmd->stop_src == TRIG_COUNT) { + unsigned int scans_left = 0; + + if (async->scans_done < cmd->stop_arg) + scans_left = cmd->stop_arg - async->scans_done; + + if (nscans > scans_left) + nscans = scans_left; + } + return nscans; +} + +/** + * comedi_nscans_left() - Return the number of scans left in the command + * @s: COMEDI subdevice. + * @nscans: The expected number of scans or 0 for all available scans. + * + * If @nscans is 0, it is set to the number of scans available in the + * async buffer. + * + * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be + * checked against the number of scans remaining to complete the command. + * + * The return value will then be either the expected number of scans or the + * number of scans remaining to complete the command, whichever is fewer. + */ +unsigned int comedi_nscans_left(struct comedi_subdevice *s, + unsigned int nscans) +{ + if (nscans == 0) { + unsigned int nbytes = comedi_buf_read_n_available(s); + + nscans = nbytes / comedi_bytes_per_scan(s); + } + return __comedi_nscans_left(s, nscans); +} +EXPORT_SYMBOL_GPL(comedi_nscans_left); + +/** + * comedi_nsamples_left() - Return the number of samples left in the command + * @s: COMEDI subdevice. + * @nsamples: The expected number of samples. + * + * Returns the number of samples remaining to complete the command, or the + * specified expected number of samples (@nsamples), whichever is fewer. + */ +unsigned int comedi_nsamples_left(struct comedi_subdevice *s, + unsigned int nsamples) +{ + struct comedi_async *async = s->async; + struct comedi_cmd *cmd = &async->cmd; + unsigned long long scans_left; + unsigned long long samples_left; + + if (cmd->stop_src != TRIG_COUNT) + return nsamples; + + scans_left = __comedi_nscans_left(s, cmd->stop_arg); + if (!scans_left) + return 0; + + samples_left = scans_left * cmd->scan_end_arg - + comedi_bytes_to_samples(s, async->scan_progress); + + if (samples_left < nsamples) + return samples_left; + return nsamples; +} +EXPORT_SYMBOL_GPL(comedi_nsamples_left); + +/** + * comedi_inc_scan_progress() - Update scan progress in asynchronous command + * @s: COMEDI subdevice. + * @num_bytes: Amount of data in bytes to increment scan progress. + * + * Increments the scan progress by the number of bytes specified by @num_bytes. + * If the scan progress reaches or exceeds the scan length in bytes, reduce + * it modulo the scan length in bytes and set the "end of scan" asynchronous + * event flag (%COMEDI_CB_EOS) to be processed later. + */ +void comedi_inc_scan_progress(struct comedi_subdevice *s, + unsigned int num_bytes) +{ + struct comedi_async *async = s->async; + struct comedi_cmd *cmd = &async->cmd; + unsigned int scan_length = comedi_bytes_per_scan(s); + + /* track the 'cur_chan' for non-SDF_PACKED subdevices */ + if (!(s->subdev_flags & SDF_PACKED)) { + async->cur_chan += comedi_bytes_to_samples(s, num_bytes); + async->cur_chan %= cmd->chanlist_len; + } + + async->scan_progress += num_bytes; + if (async->scan_progress >= scan_length) { + unsigned int nscans = async->scan_progress / scan_length; + + if (async->scans_done < (UINT_MAX - nscans)) + async->scans_done += nscans; + else + async->scans_done = UINT_MAX; + + async->scan_progress %= scan_length; + async->events |= COMEDI_CB_EOS; + } +} +EXPORT_SYMBOL_GPL(comedi_inc_scan_progress); + +/** + * comedi_handle_events() - Handle events and possibly stop acquisition + * @dev: COMEDI device. + * @s: COMEDI subdevice. + * + * Handles outstanding asynchronous acquisition event flags associated + * with the subdevice. Call the subdevice's @s->cancel() handler if the + * "end of acquisition", "error" or "overflow" event flags are set in order + * to stop the acquisition at the driver level. + * + * Calls comedi_event() to further process the event flags, which may mark + * the asynchronous command as no longer running, possibly terminated with + * an error, and may wake up tasks. + * + * Return a bit-mask of the handled events. + */ +unsigned int comedi_handle_events(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + unsigned int events = s->async->events; + + if (events == 0) + return events; + + if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel) + s->cancel(dev, s); + + comedi_event(dev, s); + + return events; +} +EXPORT_SYMBOL_GPL(comedi_handle_events); + +static int insn_rw_emulate_bits(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data) +{ + struct comedi_insn _insn; + unsigned int chan = CR_CHAN(insn->chanspec); + unsigned int base_chan = (chan < 32) ? 0 : chan; + unsigned int _data[2]; + int ret; + + memset(_data, 0, sizeof(_data)); + memset(&_insn, 0, sizeof(_insn)); + _insn.insn = INSN_BITS; + _insn.chanspec = base_chan; + _insn.n = 2; + _insn.subdev = insn->subdev; + + if (insn->insn == INSN_WRITE) { + if (!(s->subdev_flags & SDF_WRITABLE)) + return -EINVAL; + _data[0] = 1 << (chan - base_chan); /* mask */ + _data[1] = data[0] ? (1 << (chan - base_chan)) : 0; /* bits */ + } + + ret = s->insn_bits(dev, s, &_insn, _data); + if (ret < 0) + return ret; + + if (insn->insn == INSN_READ) + data[0] = (_data[1] >> (chan - base_chan)) & 1; + + return 1; +} + +static int __comedi_device_postconfig_async(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + struct comedi_async *async; + unsigned int buf_size; + int ret; + + lockdep_assert_held(&dev->mutex); + if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) { + dev_warn(dev->class_dev, + "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n"); + return -EINVAL; + } + if (!s->do_cmdtest) { + dev_warn(dev->class_dev, + "async subdevices must have a do_cmdtest() function\n"); + return -EINVAL; + } + if (!s->cancel) + dev_warn(dev->class_dev, + "async subdevices should have a cancel() function\n"); + + async = kzalloc(sizeof(*async), GFP_KERNEL); + if (!async) + return -ENOMEM; + + init_waitqueue_head(&async->wait_head); + s->async = async; + + async->max_bufsize = comedi_default_buf_maxsize_kb * 1024; + buf_size = comedi_default_buf_size_kb * 1024; + if (buf_size > async->max_bufsize) + buf_size = async->max_bufsize; + + if (comedi_buf_alloc(dev, s, buf_size) < 0) { + dev_warn(dev->class_dev, "Buffer allocation failed\n"); + return -ENOMEM; + } + if (s->buf_change) { + ret = s->buf_change(dev, s); + if (ret < 0) + return ret; + } + + comedi_alloc_subdevice_minor(s); + + return 0; +} + +static int __comedi_device_postconfig(struct comedi_device *dev) +{ + struct comedi_subdevice *s; + int ret; + int i; + + lockdep_assert_held(&dev->mutex); + if (!dev->insn_device_config) + dev->insn_device_config = insn_device_inval; + + if (!dev->get_valid_routes) + dev->get_valid_routes = get_zero_valid_routes; + + for (i = 0; i < dev->n_subdevices; i++) { + s = &dev->subdevices[i]; + + if (s->type == COMEDI_SUBD_UNUSED) + continue; + + if (s->type == COMEDI_SUBD_DO) { + if (s->n_chan < 32) + s->io_bits = (1 << s->n_chan) - 1; + else + s->io_bits = 0xffffffff; + } + + if (s->len_chanlist == 0) + s->len_chanlist = 1; + + if (s->do_cmd) { + ret = __comedi_device_postconfig_async(dev, s); + if (ret) + return ret; + } + + if (!s->range_table && !s->range_table_list) + s->range_table = &range_unknown; + + if (!s->insn_read && s->insn_bits) + s->insn_read = insn_rw_emulate_bits; + if (!s->insn_write && s->insn_bits) + s->insn_write = insn_rw_emulate_bits; + + if (!s->insn_read) + s->insn_read = insn_inval; + if (!s->insn_write) + s->insn_write = insn_inval; + if (!s->insn_bits) + s->insn_bits = insn_inval; + if (!s->insn_config) + s->insn_config = insn_inval; + + if (!s->poll) + s->poll = poll_invalid; + } + + return 0; +} + +/* do a little post-config cleanup */ +static int comedi_device_postconfig(struct comedi_device *dev) +{ + int ret; + + lockdep_assert_held(&dev->mutex); + ret = __comedi_device_postconfig(dev); + if (ret < 0) + return ret; + down_write(&dev->attach_lock); + dev->attached = true; + up_write(&dev->attach_lock); + return 0; +} + +/* + * Generic recognize function for drivers that register their supported + * board names. + * + * 'driv->board_name' points to a 'const char *' member within the + * zeroth element of an array of some private board information + * structure, say 'struct foo_board' containing a member 'const char + * *board_name' that is initialized to point to a board name string that + * is one of the candidates matched against this function's 'name' + * parameter. + * + * 'driv->offset' is the size of the private board information + * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is + * the length of the array of private board information structures. + * + * If one of the board names in the array of private board information + * structures matches the name supplied to this function, the function + * returns a pointer to the pointer to the board name, otherwise it + * returns NULL. The return value ends up in the 'board_ptr' member of + * a 'struct comedi_device' that the low-level comedi driver's + * 'attach()' hook can convert to a point to a particular element of its + * array of private board information structures by subtracting the + * offset of the member that points to the board name. (No subtraction + * is required if the board name pointer is the first member of the + * private board information structure, which is generally the case.) + */ +static void *comedi_recognize(struct comedi_driver *driv, const char *name) +{ + char **name_ptr = (char **)driv->board_name; + int i; + + for (i = 0; i < driv->num_names; i++) { + if (strcmp(*name_ptr, name) == 0) + return name_ptr; + name_ptr = (void *)name_ptr + driv->offset; + } + + return NULL; +} + +static void comedi_report_boards(struct comedi_driver *driv) +{ + unsigned int i; + const char *const *name_ptr; + + pr_info("comedi: valid board names for %s driver are:\n", + driv->driver_name); + + name_ptr = driv->board_name; + for (i = 0; i < driv->num_names; i++) { + pr_info(" %s\n", *name_ptr); + name_ptr = (const char **)((char *)name_ptr + driv->offset); + } + + if (driv->num_names == 0) + pr_info(" %s\n", driv->driver_name); +} + +/** + * comedi_load_firmware() - Request and load firmware for a device + * @dev: COMEDI device. + * @device: Hardware device. + * @name: The name of the firmware image. + * @cb: Callback to the upload the firmware image. + * @context: Private context from the driver. + * + * Sends a firmware request for the hardware device and waits for it. Calls + * the callback function to upload the firmware to the device, them releases + * the firmware. + * + * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number + * from the firmware request or the callback function. + */ +int comedi_load_firmware(struct comedi_device *dev, + struct device *device, + const char *name, + int (*cb)(struct comedi_device *dev, + const u8 *data, size_t size, + unsigned long context), + unsigned long context) +{ + const struct firmware *fw; + int ret; + + if (!cb) + return -EINVAL; + + ret = request_firmware(&fw, name, device); + if (ret == 0) { + ret = cb(dev, fw->data, fw->size, context); + release_firmware(fw); + } + + return ret < 0 ? ret : 0; +} +EXPORT_SYMBOL_GPL(comedi_load_firmware); + +/** + * __comedi_request_region() - Request an I/O region for a legacy driver + * @dev: COMEDI device. + * @start: Base address of the I/O region. + * @len: Length of the I/O region. + * + * Requests the specified I/O port region which must start at a non-zero + * address. + * + * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request + * fails. + */ +int __comedi_request_region(struct comedi_device *dev, + unsigned long start, unsigned long len) +{ + if (!start) { + dev_warn(dev->class_dev, + "%s: a I/O base address must be specified\n", + dev->board_name); + return -EINVAL; + } + + if (!request_region(start, len, dev->board_name)) { + dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n", + dev->board_name, start, len); + return -EIO; + } + + return 0; +} +EXPORT_SYMBOL_GPL(__comedi_request_region); + +/** + * comedi_request_region() - Request an I/O region for a legacy driver + * @dev: COMEDI device. + * @start: Base address of the I/O region. + * @len: Length of the I/O region. + * + * Requests the specified I/O port region which must start at a non-zero + * address. + * + * On success, @dev->iobase is set to the base address of the region and + * @dev->iolen is set to its length. + * + * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request + * fails. + */ +int comedi_request_region(struct comedi_device *dev, + unsigned long start, unsigned long len) +{ + int ret; + + ret = __comedi_request_region(dev, start, len); + if (ret == 0) { + dev->iobase = start; + dev->iolen = len; + } + + return ret; +} +EXPORT_SYMBOL_GPL(comedi_request_region); + +/** + * comedi_legacy_detach() - A generic (*detach) function for legacy drivers + * @dev: COMEDI device. + * + * This is a simple, generic 'detach' handler for legacy COMEDI devices that + * just use a single I/O port region and possibly an IRQ and that don't need + * any special clean-up for their private device or subdevice storage. It + * can also be called by a driver-specific 'detach' handler. + * + * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and + * @dev->iolen are both non-zero, the I/O port region will be released. + */ +void comedi_legacy_detach(struct comedi_device *dev) +{ + if (dev->irq) { + free_irq(dev->irq, dev); + dev->irq = 0; + } + if (dev->iobase && dev->iolen) { + release_region(dev->iobase, dev->iolen); + dev->iobase = 0; + dev->iolen = 0; + } +} +EXPORT_SYMBOL_GPL(comedi_legacy_detach); + +int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) +{ + struct comedi_driver *driv; + int ret; + + lockdep_assert_held(&dev->mutex); + if (dev->attached) + return -EBUSY; + + mutex_lock(&comedi_drivers_list_lock); + for (driv = comedi_drivers; driv; driv = driv->next) { + if (!try_module_get(driv->module)) + continue; + if (driv->num_names) { + dev->board_ptr = comedi_recognize(driv, it->board_name); + if (dev->board_ptr) + break; + } else if (strcmp(driv->driver_name, it->board_name) == 0) { + break; + } + module_put(driv->module); + } + if (!driv) { + /* recognize has failed if we get here */ + /* report valid board names before returning error */ + for (driv = comedi_drivers; driv; driv = driv->next) { + if (!try_module_get(driv->module)) + continue; + comedi_report_boards(driv); + module_put(driv->module); + } + ret = -EIO; + goto out; + } + if (!driv->attach) { + /* driver does not support manual configuration */ + dev_warn(dev->class_dev, + "driver '%s' does not support attach using comedi_config\n", + driv->driver_name); + module_put(driv->module); + ret = -EIO; + goto out; + } + dev->driver = driv; + dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr + : dev->driver->driver_name; + ret = driv->attach(dev, it); + if (ret >= 0) + ret = comedi_device_postconfig(dev); + if (ret < 0) { + comedi_device_detach(dev); + module_put(driv->module); + } + /* On success, the driver module count has been incremented. */ +out: + mutex_unlock(&comedi_drivers_list_lock); + return ret; +} + +/** + * comedi_auto_config() - Create a COMEDI device for a hardware device + * @hardware_device: Hardware device. + * @driver: COMEDI low-level driver for the hardware device. + * @context: Driver context for the auto_attach handler. + * + * Allocates a new COMEDI device for the hardware device and calls the + * low-level driver's 'auto_attach' handler to set-up the hardware and + * allocate the COMEDI subdevices. Additional "post-configuration" setting + * up is performed on successful return from the 'auto_attach' handler. + * If the 'auto_attach' handler fails, the low-level driver's 'detach' + * handler will be called as part of the clean-up. + * + * This is usually called from a wrapper function in a bus-specific COMEDI + * module, which in turn is usually called from a bus device 'probe' + * function in the low-level driver. + * + * Returns 0 on success, -EINVAL if the parameters are invalid or the + * post-configuration determines the driver has set the COMEDI device up + * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of + * COMEDI minor device numbers, or some negative error number returned by + * the driver's 'auto_attach' handler. + */ +int comedi_auto_config(struct device *hardware_device, + struct comedi_driver *driver, unsigned long context) +{ + struct comedi_device *dev; + int ret; + + if (!hardware_device) { + pr_warn("BUG! %s called with NULL hardware_device\n", __func__); + return -EINVAL; + } + if (!driver) { + dev_warn(hardware_device, + "BUG! %s called with NULL comedi driver\n", __func__); + return -EINVAL; + } + + if (!driver->auto_attach) { + dev_warn(hardware_device, + "BUG! comedi driver '%s' has no auto_attach handler\n", + driver->driver_name); + return -EINVAL; + } + + dev = comedi_alloc_board_minor(hardware_device); + if (IS_ERR(dev)) { + dev_warn(hardware_device, + "driver '%s' could not create device.\n", + driver->driver_name); + return PTR_ERR(dev); + } + /* Note: comedi_alloc_board_minor() locked dev->mutex. */ + lockdep_assert_held(&dev->mutex); + + dev->driver = driver; + dev->board_name = dev->driver->driver_name; + ret = driver->auto_attach(dev, context); + if (ret >= 0) + ret = comedi_device_postconfig(dev); + + if (ret < 0) { + dev_warn(hardware_device, + "driver '%s' failed to auto-configure device.\n", + driver->driver_name); + mutex_unlock(&dev->mutex); + comedi_release_hardware_device(hardware_device); + } else { + /* + * class_dev should be set properly here + * after a successful auto config + */ + dev_info(dev->class_dev, + "driver '%s' has successfully auto-configured '%s'.\n", + driver->driver_name, dev->board_name); + mutex_unlock(&dev->mutex); + } + return ret; +} +EXPORT_SYMBOL_GPL(comedi_auto_config); + +/** + * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device + * @hardware_device: Hardware device previously passed to + * comedi_auto_config(). + * + * Cleans up and eventually destroys the COMEDI device allocated by + * comedi_auto_config() for the same hardware device. As part of this + * clean-up, the low-level COMEDI driver's 'detach' handler will be called. + * (The COMEDI device itself will persist in an unattached state if it is + * still open, until it is released, and any mmapped buffers will persist + * until they are munmapped.) + * + * This is usually called from a wrapper module in a bus-specific COMEDI + * module, which in turn is usually set as the bus device 'remove' function + * in the low-level COMEDI driver. + */ +void comedi_auto_unconfig(struct device *hardware_device) +{ + if (!hardware_device) + return; + comedi_release_hardware_device(hardware_device); +} +EXPORT_SYMBOL_GPL(comedi_auto_unconfig); + +/** + * comedi_driver_register() - Register a low-level COMEDI driver + * @driver: Low-level COMEDI driver. + * + * The low-level COMEDI driver is added to the list of registered COMEDI + * drivers. This is used by the handler for the "/proc/comedi" file and is + * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure + * "legacy" COMEDI devices (for those low-level drivers that support it). + * + * Returns 0. + */ +int comedi_driver_register(struct comedi_driver *driver) +{ + mutex_lock(&comedi_drivers_list_lock); + driver->next = comedi_drivers; + comedi_drivers = driver; + mutex_unlock(&comedi_drivers_list_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(comedi_driver_register); + +/** + * comedi_driver_unregister() - Unregister a low-level COMEDI driver + * @driver: Low-level COMEDI driver. + * + * The low-level COMEDI driver is removed from the list of registered COMEDI + * drivers. Detaches any COMEDI devices attached to the driver, which will + * result in the low-level driver's 'detach' handler being called for those + * devices before this function returns. + */ +void comedi_driver_unregister(struct comedi_driver *driver) +{ + struct comedi_driver *prev; + int i; + + /* unlink the driver */ + mutex_lock(&comedi_drivers_list_lock); + if (comedi_drivers == driver) { + comedi_drivers = driver->next; + } else { + for (prev = comedi_drivers; prev->next; prev = prev->next) { + if (prev->next == driver) { + prev->next = driver->next; + break; + } + } + } + mutex_unlock(&comedi_drivers_list_lock); + + /* check for devices using this driver */ + for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { + struct comedi_device *dev = comedi_dev_get_from_minor(i); + + if (!dev) + continue; + + mutex_lock(&dev->mutex); + if (dev->attached && dev->driver == driver) { + if (dev->use_count) + dev_warn(dev->class_dev, + "BUG! detaching device with use_count=%d\n", + dev->use_count); + comedi_device_detach(dev); + } + mutex_unlock(&dev->mutex); + comedi_dev_put(dev); + } +} +EXPORT_SYMBOL_GPL(comedi_driver_unregister); |