631e272b12
Some of the header files in "drivers/comedi/drivers/" are common enough to be useful to out-of-tree comedi driver modules. Using them for out-of-tree module builds is hampered by the headers being outside the "include/" directory so it is desirable to move them. There are about a couple of dozen Comedi device drivers that use the "comedi_8255" module to add digital I/O subdevices based on the venerable 8255 Programmable Peripheral Interface chip. The macros and declarations to use that module are in the "8255.h" header file in the comedi "drivers" directory. Move it into "include/linux/comedi/" and rename it to "comedi_8255.h" for naming consistency reasons. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20211117120604.117740-4-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
125 lines
3.3 KiB
C
125 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* comedi/drivers/8255.c
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* Driver for 8255
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*
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* COMEDI - Linux Control and Measurement Device Interface
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* Copyright (C) 1998 David A. Schleef <ds@schleef.org>
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*/
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/*
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* Driver: 8255
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* Description: generic 8255 support
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* Devices: [standard] 8255 (8255)
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* Author: ds
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* Status: works
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* Updated: Fri, 7 Jun 2002 12:56:45 -0700
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*
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* The classic in digital I/O. The 8255 appears in Comedi as a single
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* digital I/O subdevice with 24 channels. The channel 0 corresponds
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* to the 8255's port A, bit 0; channel 23 corresponds to port C, bit
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* 7. Direction configuration is done in blocks, with channels 0-7,
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* 8-15, 16-19, and 20-23 making up the 4 blocks. The only 8255 mode
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* supported is mode 0.
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*
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* You should enable compilation this driver if you plan to use a board
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* that has an 8255 chip. For multifunction boards, the main driver will
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* configure the 8255 subdevice automatically.
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*
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* This driver also works independently with ISA and PCI cards that
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* directly map the 8255 registers to I/O ports, including cards with
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* multiple 8255 chips. To configure the driver for such a card, the
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* option list should be a list of the I/O port bases for each of the
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* 8255 chips. For example,
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*
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* comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
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*
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* Note that most PCI 8255 boards do NOT work with this driver, and
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* need a separate driver as a wrapper. For those that do work, the
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* I/O port base address can be found in the output of 'lspci -v'.
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*/
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#include <linux/module.h>
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#include <linux/comedi/comedidev.h>
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#include <linux/comedi/comedi_8255.h>
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static int dev_8255_attach(struct comedi_device *dev,
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struct comedi_devconfig *it)
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{
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struct comedi_subdevice *s;
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unsigned long iobase;
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int ret;
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int i;
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for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
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iobase = it->options[i];
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if (!iobase)
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break;
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}
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if (i == 0) {
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dev_warn(dev->class_dev, "no devices specified\n");
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return -EINVAL;
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}
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ret = comedi_alloc_subdevices(dev, i);
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if (ret)
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return ret;
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for (i = 0; i < dev->n_subdevices; i++) {
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s = &dev->subdevices[i];
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iobase = it->options[i];
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/*
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* __comedi_request_region() does not set dev->iobase.
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*
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* For 8255 devices that are manually attached using
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* comedi_config, the 'iobase' is the actual I/O port
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* base address of the chip.
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*/
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ret = __comedi_request_region(dev, iobase, I8255_SIZE);
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if (ret) {
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s->type = COMEDI_SUBD_UNUSED;
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} else {
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ret = subdev_8255_init(dev, s, NULL, iobase);
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if (ret) {
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/*
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* Release the I/O port region here, as the
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* "detach" handler cannot find it.
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*/
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release_region(iobase, I8255_SIZE);
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s->type = COMEDI_SUBD_UNUSED;
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return ret;
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}
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}
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}
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return 0;
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}
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static void dev_8255_detach(struct comedi_device *dev)
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{
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struct comedi_subdevice *s;
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int i;
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for (i = 0; i < dev->n_subdevices; i++) {
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s = &dev->subdevices[i];
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if (s->type != COMEDI_SUBD_UNUSED) {
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unsigned long regbase = subdev_8255_regbase(s);
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release_region(regbase, I8255_SIZE);
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}
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}
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}
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static struct comedi_driver dev_8255_driver = {
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.driver_name = "8255",
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.module = THIS_MODULE,
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.attach = dev_8255_attach,
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.detach = dev_8255_detach,
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};
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module_comedi_driver(dev_8255_driver);
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MODULE_AUTHOR("Comedi https://www.comedi.org");
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MODULE_DESCRIPTION("Comedi driver for standalone 8255 devices");
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MODULE_LICENSE("GPL");
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