diff options
Diffstat (limited to 'drivers/staging/comedi/drivers/comedi_bond.c')
| -rw-r--r-- | drivers/staging/comedi/drivers/comedi_bond.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers/comedi_bond.c b/drivers/staging/comedi/drivers/comedi_bond.c new file mode 100644 index 000000000000..9e5496f4f1ae --- /dev/null +++ b/drivers/staging/comedi/drivers/comedi_bond.c @@ -0,0 +1,535 @@ +/* + comedi/drivers/comedi_bond.c + A Comedi driver to 'bond' or merge multiple drivers and devices as one. + + COMEDI - Linux Control and Measurement Device Interface + Copyright (C) 2000 David A. Schleef <ds@schleef.org> + Copyright (C) 2005 Calin A. Culianu <calin@ajvar.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +*/ +/* +Driver: comedi_bond +Description: A driver to 'bond' (merge) multiple subdevices from multiple + devices together as one. +Devices: +Author: ds +Updated: Mon, 10 Oct 00:18:25 -0500 +Status: works + +This driver allows you to 'bond' (merge) multiple comedi subdevices +(coming from possibly difference boards and/or drivers) together. For +example, if you had a board with 2 different DIO subdevices, and +another with 1 DIO subdevice, you could 'bond' them with this driver +so that they look like one big fat DIO subdevice. This makes writing +applications slightly easier as you don't have to worry about managing +different subdevices in the application -- you just worry about +indexing one linear array of channel id's. + +Right now only DIO subdevices are supported as that's the personal itch +I am scratching with this driver. If you want to add support for AI and AO +subdevs, go right on ahead and do so! + +Commands aren't supported -- although it would be cool if they were. + +Configuration Options: + List of comedi-minors to bond. All subdevices of the same type + within each minor will be concatenated together in the order given here. +*/ + +/* + * The previous block comment is used to automatically generate + * documentation in Comedi and Comedilib. The fields: + * + * Driver: the name of the driver + * Description: a short phrase describing the driver. Don't list boards. + * Devices: a full list of the boards that attempt to be supported by + * the driver. Format is "(manufacturer) board name [comedi name]", + * where comedi_name is the name that is used to configure the board. + * See the comment near board_name: in the comedi_driver structure + * below. If (manufacturer) or [comedi name] is missing, the previous + * value is used. + * Author: you + * Updated: date when the _documentation_ was last updated. Use 'date -R' + * to get a value for this. + * Status: a one-word description of the status. Valid values are: + * works - driver works correctly on most boards supported, and + * passes comedi_test. + * unknown - unknown. Usually put there by ds. + * experimental - may not work in any particular release. Author + * probably wants assistance testing it. + * bitrotten - driver has not been update in a long time, probably + * doesn't work, and probably is missing support for significant + * Comedi interface features. + * untested - author probably wrote it "blind", and is believed to + * work, but no confirmation. + * + * These headers should be followed by a blank line, and any comments + * you wish to say about the driver. The comment area is the place + * to put any known bugs, limitations, unsupported features, supported + * command triggers, whether or not commands are supported on particular + * subdevices, etc. + * + * Somewhere in the comment should be information about configuration + * options that are used with comedi_config. + */ + +#include "../comedilib.h" +#include "../comedidev.h" +#include <linux/string.h> + +/* The maxiumum number of channels per subdevice. */ +#define MAX_CHANS 256 + +#define MODULE_NAME "comedi_bond" +#ifdef MODULE_LICENSE +MODULE_LICENSE("GPL"); +#endif +#ifndef STR +# define STR1(x) #x +# define STR(x) STR1(x) +#endif + +static int debug; +module_param(debug, int, 0644); +MODULE_PARM_DESC(debug, "If true, print extra cryptic debugging output useful" + "only to developers."); + +#define LOG_MSG(x...) printk(KERN_INFO MODULE_NAME": "x) +#define DEBUG(x...) \ + do { \ + if (debug) \ + printk(KERN_DEBUG MODULE_NAME": DEBUG: "x); \ + } while (0) +#define WARNING(x...) printk(KERN_WARNING MODULE_NAME ": WARNING: "x) +#define ERROR(x...) printk(KERN_ERR MODULE_NAME ": INTERNAL ERROR: "x) +MODULE_AUTHOR("Calin A. Culianu"); +MODULE_DESCRIPTION(MODULE_NAME "A driver for COMEDI to bond multiple COMEDI " + "devices together as one. In the words of John Lennon: " + "'And the world will live as one...'"); + +/* + * Board descriptions for two imaginary boards. Describing the + * boards in this way is optional, and completely driver-dependent. + * Some drivers use arrays such as this, other do not. + */ +struct BondingBoard { + const char *name; +}; + +static const struct BondingBoard bondingBoards[] = { + { + .name = MODULE_NAME, + }, +}; + +/* + * Useful for shorthand access to the particular board structure + */ +#define thisboard ((const struct BondingBoard *)dev->board_ptr) + +struct BondedDevice { + comedi_t *dev; + unsigned minor; + unsigned subdev; + unsigned subdev_type; + unsigned nchans; + unsigned chanid_offset; /* The offset into our unified linear + channel-id's of chanid 0 on this + subdevice. */ +}; + +/* this structure is for data unique to this hardware driver. If + several hardware drivers keep similar information in this structure, + feel free to suggest moving the variable to the comedi_device struct. */ +struct Private { +# define MAX_BOARD_NAME 256 + char name[MAX_BOARD_NAME]; + struct BondedDevice **devs; + unsigned ndevs; + struct BondedDevice *chanIdDevMap[MAX_CHANS]; + unsigned nchans; +}; + +/* + * most drivers define the following macro to make it easy to + * access the private structure. + */ +#define devpriv ((struct Private *)dev->private) + +/* + * The comedi_driver structure tells the Comedi core module + * which functions to call to configure/deconfigure (attach/detach) + * the board, and also about the kernel module that contains + * the device code. + */ +static int bonding_attach(comedi_device *dev, comedi_devconfig *it); +static int bonding_detach(comedi_device *dev); +/** Build Private array of all devices.. */ +static int doDevConfig(comedi_device *dev, comedi_devconfig *it); +static void doDevUnconfig(comedi_device *dev); +/* Ugly implementation of realloc that always copies memory around -- I'm lazy, + * what can I say? I like to do wasteful memcopies.. :) */ +static void *Realloc(const void *ptr, size_t len, size_t old_len); + +static comedi_driver driver_bonding = { + .driver_name = MODULE_NAME, + .module = THIS_MODULE, + .attach = bonding_attach, + .detach = bonding_detach, + /* It is not necessary to implement the following members if you are + * writing a driver for a ISA PnP or PCI card */ + /* Most drivers will support multiple types of boards by + * having an array of board structures. These were defined + * in skel_boards[] above. Note that the element 'name' + * was first in the structure -- Comedi uses this fact to + * extract the name of the board without knowing any details + * about the structure except for its length. + * When a device is attached (by comedi_config), the name + * of the device is given to Comedi, and Comedi tries to + * match it by going through the list of board names. If + * there is a match, the address of the pointer is put + * into dev->board_ptr and driver->attach() is called. + * + * Note that these are not necessary if you can determine + * the type of board in software. ISA PnP, PCI, and PCMCIA + * devices are such boards. + */ + .board_name = &bondingBoards[0].name, + .offset = sizeof(struct BondingBoard), + .num_names = sizeof(bondingBoards) / sizeof(struct BondingBoard), +}; + +static int bonding_dio_insn_bits(comedi_device *dev, comedi_subdevice *s, + comedi_insn *insn, lsampl_t *data); +static int bonding_dio_insn_config(comedi_device *dev, comedi_subdevice *s, + comedi_insn *insn, lsampl_t *data); + +/* + * Attach is called by the Comedi core to configure the driver + * for a particular board. If you specified a board_name array + * in the driver structure, dev->board_ptr contains that + * address. + */ +static int bonding_attach(comedi_device *dev, comedi_devconfig *it) +{ + comedi_subdevice *s; + + LOG_MSG("comedi%d\n", dev->minor); + + /* + * Allocate the private structure area. alloc_private() is a + * convenient macro defined in comedidev.h. + */ + if (alloc_private(dev, sizeof(struct Private)) < 0) + return -ENOMEM; + + /* + * Setup our bonding from config params.. sets up our Private struct.. + */ + if (!doDevConfig(dev, it)) + return -EINVAL; + + /* + * Initialize dev->board_name. Note that we can use the "thisboard" + * macro now, since we just initialized it in the last line. + */ + dev->board_name = devpriv->name; + + /* + * Allocate the subdevice structures. alloc_subdevice() is a + * convenient macro defined in comedidev.h. + */ + if (alloc_subdevices(dev, 1) < 0) + return -ENOMEM; + + s = dev->subdevices + 0; + s->type = COMEDI_SUBD_DIO; + s->subdev_flags = SDF_READABLE | SDF_WRITABLE; + s->n_chan = devpriv->nchans; + s->maxdata = 1; + s->range_table = &range_digital; + s->insn_bits = bonding_dio_insn_bits; + s->insn_config = bonding_dio_insn_config; + + LOG_MSG("attached with %u DIO channels coming from %u different " + "subdevices all bonded together. " + "John Lennon would be proud!\n", + devpriv->nchans, devpriv->ndevs); + + return 1; +} + +/* + * _detach is called to deconfigure a device. It should deallocate + * resources. + * This function is also called when _attach() fails, so it should be + * careful not to release resources that were not necessarily + * allocated by _attach(). dev->private and dev->subdevices are + * deallocated automatically by the core. + */ +static int bonding_detach(comedi_device *dev) +{ + LOG_MSG("comedi%d: remove\n", dev->minor); + doDevUnconfig(dev); + return 0; +} + +/* DIO devices are slightly special. Although it is possible to + * implement the insn_read/insn_write interface, it is much more + * useful to applications if you implement the insn_bits interface. + * This allows packed reading/writing of the DIO channels. The + * comedi core can convert between insn_bits and insn_read/write */ +static int bonding_dio_insn_bits(comedi_device *dev, comedi_subdevice *s, + comedi_insn *insn, lsampl_t *data) +{ +#define LSAMPL_BITS (sizeof(lsampl_t)*8) + unsigned nchans = LSAMPL_BITS, num_done = 0, i; + if (insn->n != 2) + return -EINVAL; + + if (devpriv->nchans < nchans) + nchans = devpriv->nchans; + + /* The insn data is a mask in data[0] and the new data + * in data[1], each channel cooresponding to a bit. */ + for (i = 0; num_done < nchans && i < devpriv->ndevs; ++i) { + struct BondedDevice *bdev = devpriv->devs[i]; + /* Grab the channel mask and data of only the bits corresponding + to this subdevice.. need to shift them to zero position of + course. */ + /* Bits corresponding to this subdev. */ + lsampl_t subdevMask = ((1 << bdev->nchans) - 1); + lsampl_t writeMask, dataBits; + + /* Argh, we have >= LSAMPL_BITS chans.. take all bits */ + if (bdev->nchans >= LSAMPL_BITS) + subdevMask = (lsampl_t) (-1); + + writeMask = (data[0] >> num_done) & subdevMask; + dataBits = (data[1] >> num_done) & subdevMask; + + /* Read/Write the new digital lines */ + if (comedi_dio_bitfield(bdev->dev, bdev->subdev, writeMask, + &dataBits) != 2) + return -EINVAL; + + /* Make room for the new bits in data[1], the return value */ + data[1] &= ~(subdevMask << num_done); + /* Put the bits in the return value */ + data[1] |= (dataBits & subdevMask) << num_done; + /* Save the new bits to the saved state.. */ + s->state = data[1]; + + num_done += bdev->nchans; + } + + return insn->n; +} + +static int bonding_dio_insn_config(comedi_device *dev, comedi_subdevice *s, + comedi_insn *insn, lsampl_t *data) +{ + int chan = CR_CHAN(insn->chanspec), ret, io_bits = s->io_bits; + unsigned int io; + struct BondedDevice *bdev; + + if (chan < 0 || chan >= devpriv->nchans) + return -EINVAL; + bdev = devpriv->chanIdDevMap[chan]; + + /* The input or output configuration of each digital line is + * configured by a special insn_config instruction. chanspec + * contains the channel to be changed, and data[0] contains the + * value COMEDI_INPUT or COMEDI_OUTPUT. */ + switch (data[0]) { + case INSN_CONFIG_DIO_OUTPUT: + io = COMEDI_OUTPUT; /* is this really necessary? */ + io_bits |= 1 << chan; + break; + case INSN_CONFIG_DIO_INPUT: + io = COMEDI_INPUT; /* is this really necessary? */ + io_bits &= ~(1 << chan); + break; + case INSN_CONFIG_DIO_QUERY: + data[1] = + (io_bits & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT; + return insn->n; + break; + default: + return -EINVAL; + break; + } + /* 'real' channel id for this subdev.. */ + chan -= bdev->chanid_offset; + ret = comedi_dio_config(bdev->dev, bdev->subdev, chan, io); + if (ret != 1) + return -EINVAL; + /* Finally, save the new io_bits values since we didn't get + an error above. */ + s->io_bits = io_bits; + return insn->n; +} + +static void *Realloc(const void *oldmem, size_t newlen, size_t oldlen) +{ + void *newmem = kmalloc(newlen, GFP_KERNEL); + + if (newmem && oldmem) + memcpy(newmem, oldmem, min(oldlen, newlen)); + kfree(oldmem); + return newmem; +} + +static int doDevConfig(comedi_device *dev, comedi_devconfig *it) +{ + int i; + comedi_t *devs_opened[COMEDI_NUM_BOARD_MINORS]; + + memset(devs_opened, 0, sizeof(devs_opened)); + devpriv->name[0] = 0;; + /* Loop through all comedi devices specified on the command-line, + building our device list */ + for (i = 0; i < COMEDI_NDEVCONFOPTS && (!i || it->options[i]); ++i) { + char file[] = "/dev/comediXXXXXX"; + int minor = it->options[i]; + comedi_t *d; + int sdev = -1, nchans, tmp; + struct BondedDevice *bdev = NULL; + + if (minor < 0 || minor > COMEDI_NUM_BOARD_MINORS) { + ERROR("Minor %d is invalid!\n", minor); + return 0; + } + if (minor == dev->minor) { + ERROR("Cannot bond this driver to itself!\n"); + return 0; + } + if (devs_opened[minor]) { + ERROR("Minor %d specified more than once!\n", minor); + return 0; + } + + snprintf(file, sizeof(file), "/dev/comedi%u", minor); + file[sizeof(file) - 1] = 0; + + d = devs_opened[minor] = comedi_open(file); + + if (!d) { + ERROR("Minor %u could not be opened\n", minor); + return 0; + } + + /* Do DIO, as that's all we support now.. */ + while ((sdev = comedi_find_subdevice_by_type(d, COMEDI_SUBD_DIO, + sdev + 1)) > -1) { + nchans = comedi_get_n_channels(d, sdev); + if (nchans <= 0) { + ERROR("comedi_get_n_channels() returned %d " + "on minor %u subdev %d!\n", + nchans, minor, sdev); + return 0; + } + bdev = kmalloc(sizeof(*bdev), GFP_KERNEL); + if (!bdev) { + ERROR("Out of memory.\n"); + return 0; + } + bdev->dev = d; + bdev->minor = minor; + bdev->subdev = sdev; + bdev->subdev_type = COMEDI_SUBD_DIO; + bdev->nchans = nchans; + bdev->chanid_offset = devpriv->nchans; + + /* map channel id's to BondedDevice * pointer.. */ + while (nchans--) + devpriv->chanIdDevMap[devpriv->nchans++] = bdev; + + /* Now put bdev pointer at end of devpriv->devs array + * list.. */ + + /* ergh.. ugly.. we need to realloc :( */ + tmp = devpriv->ndevs * sizeof(bdev); + devpriv->devs = + Realloc(devpriv->devs, + ++devpriv->ndevs * sizeof(bdev), tmp); + if (!devpriv->devs) { + ERROR("Could not allocate memory. " + "Out of memory?"); + return 0; + } + + devpriv->devs[devpriv->ndevs - 1] = bdev; + { + /** Append dev:subdev to devpriv->name */ + char buf[20]; + int left = + MAX_BOARD_NAME - strlen(devpriv->name) - + 1; + snprintf(buf, sizeof(buf), "%d:%d ", dev->minor, + bdev->subdev); + buf[sizeof(buf) - 1] = 0; + strncat(devpriv->name, buf, left); + } + + } + } + + if (!devpriv->nchans) { + ERROR("No channels found!\n"); + return 0; + } + + return 1; +} + +static void doDevUnconfig(comedi_device *dev) +{ + unsigned long devs_closed = 0; + + if (devpriv) { + while (devpriv->ndevs-- && devpriv->devs) { + struct BondedDevice *bdev; + + bdev = devpriv->devs[devpriv->ndevs]; + if (!bdev) + continue; + if (!(devs_closed & (0x1 << bdev->minor))) { + comedi_close(bdev->dev); + devs_closed |= (0x1 << bdev->minor); + } + kfree(bdev); + } + kfree(devpriv->devs); + devpriv->devs = NULL; + kfree(devpriv); + dev->private = NULL; + } +} + +static int __init init(void) +{ + return comedi_driver_register(&driver_bonding); +} + +static void __exit cleanup(void) +{ + comedi_driver_unregister(&driver_bonding); +} + +module_init(init); +module_exit(cleanup); |