LXR linux/drivers/staging/comedi/drivers/amplc_pc236

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * comedi/drivers/amplc_pc236_common.c
   4 * Common support code for "amplc_pc236" and "amplc_pci236".
   5 *
   6 * Copyright (C) 2002-2014 MEV Ltd. <http://www.mev.co.uk/>
   7 *
   8 * COMEDI - Linux Control and Measurement Device Interface
   9 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/interrupt.h>
  14
  15#include "../comedidev.h"
  16
  17#include "amplc_pc236.h"
  18#include "8255.h"
  19
  20static void pc236_intr_update(struct comedi_device *dev, bool enable)
  21{
  22        const struct pc236_board *board = dev->board_ptr;
  23        struct pc236_private *devpriv = dev->private;
  24        unsigned long flags;
  25
  26        spin_lock_irqsave(&dev->spinlock, flags);
  27        devpriv->enable_irq = enable;
  28        if (board->intr_update_cb)
  29                board->intr_update_cb(dev, enable);
  30        spin_unlock_irqrestore(&dev->spinlock, flags);
  31}
  32
  33/*
  34 * This function is called when an interrupt occurs to check whether
  35 * the interrupt has been marked as enabled and was generated by the
  36 * board.  If so, the function prepares the hardware for the next
  37 * interrupt.
  38 * Returns false if the interrupt should be ignored.
  39 */
  40static bool pc236_intr_check(struct comedi_device *dev)
  41{
  42        const struct pc236_board *board = dev->board_ptr;
  43        struct pc236_private *devpriv = dev->private;
  44        bool retval = false;
  45        unsigned long flags;
  46
  47        spin_lock_irqsave(&dev->spinlock, flags);
  48        if (devpriv->enable_irq) {
  49                if (board->intr_chk_clr_cb)
  50                        retval = board->intr_chk_clr_cb(dev);
  51                else
  52                        retval = true;
  53        }
  54        spin_unlock_irqrestore(&dev->spinlock, flags);
  55
  56        return retval;
  57}
  58
  59static int pc236_intr_insn(struct comedi_device *dev,
  60                           struct comedi_subdevice *s, struct comedi_insn *insn,
  61                           unsigned int *data)
  62{
  63        data[1] = 0;
  64        return insn->n;
  65}
  66
  67static int pc236_intr_cmdtest(struct comedi_device *dev,
  68                              struct comedi_subdevice *s,
  69                              struct comedi_cmd *cmd)
  70{
  71        int err = 0;
  72
  73        /* Step 1 : check if triggers are trivially valid */
  74
  75        err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
  76        err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
  77        err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
  78        err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
  79        err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_NONE);
  80
  81        if (err)
  82                return 1;
  83
  84        /* Step 2a : make sure trigger sources are unique */
  85        /* Step 2b : and mutually compatible */
  86
  87        /* Step 3: check it arguments are trivially valid */
  88
  89        err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
  90        err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
  91        err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
  92        err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
  93                                           cmd->chanlist_len);
  94        err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
  95
  96        if (err)
  97                return 3;
  98
  99        /* Step 4: fix up any arguments */
 100
 101        /* Step 5: check channel list if it exists */
 102
 103        return 0;
 104}
 105
 106static int pc236_intr_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 107{
 108        pc236_intr_update(dev, true);
 109
 110        return 0;
 111}
 112
 113static int pc236_intr_cancel(struct comedi_device *dev,
 114                             struct comedi_subdevice *s)
 115{
 116        pc236_intr_update(dev, false);
 117
 118        return 0;
 119}
 120
 121static irqreturn_t pc236_interrupt(int irq, void *d)
 122{
 123        struct comedi_device *dev = d;
 124        struct comedi_subdevice *s = dev->read_subdev;
 125        bool handled;
 126
 127        handled = pc236_intr_check(dev);
 128        if (dev->attached && handled) {
 129                comedi_buf_write_samples(s, &s->state, 1);
 130                comedi_handle_events(dev, s);
 131        }
 132        return IRQ_RETVAL(handled);
 133}
 134
 135int amplc_pc236_common_attach(struct comedi_device *dev, unsigned long iobase,
 136                              unsigned int irq, unsigned long req_irq_flags)
 137{
 138        struct comedi_subdevice *s;
 139        int ret;
 140
 141        dev->iobase = iobase;
 142
 143        ret = comedi_alloc_subdevices(dev, 2);
 144        if (ret)
 145                return ret;
 146
 147        s = &dev->subdevices[0];
 148        /* digital i/o subdevice (8255) */
 149        ret = subdev_8255_init(dev, s, NULL, 0x00);
 150        if (ret)
 151                return ret;
 152
 153        s = &dev->subdevices[1];
 154        dev->read_subdev = s;
 155        s->type = COMEDI_SUBD_UNUSED;
 156        pc236_intr_update(dev, false);
 157        if (irq) {
 158                if (request_irq(irq, pc236_interrupt, req_irq_flags,
 159                                dev->board_name, dev) >= 0) {
 160                        dev->irq = irq;
 161                        s->type = COMEDI_SUBD_DI;
 162                        s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
 163                        s->n_chan = 1;
 164                        s->maxdata = 1;
 165                        s->range_table = &range_digital;
 166                        s->insn_bits = pc236_intr_insn;
 167                        s->len_chanlist = 1;
 168                        s->do_cmdtest = pc236_intr_cmdtest;
 169                        s->do_cmd = pc236_intr_cmd;
 170                        s->cancel = pc236_intr_cancel;
 171                }
 172        }
 173
 174        return 0;
 175}
 176EXPORT_SYMBOL_GPL(amplc_pc236_common_attach);
 177
 178static int __init amplc_pc236_common_init(void)
 179{
 180        return 0;
 181}
 182module_init(amplc_pc236_common_init);
 183
 184static void __exit amplc_pc236_common_exit(void)
 185{
 186}
 187module_exit(amplc_pc236_common_exit);
 188
 189MODULE_AUTHOR("Comedi http://www.comedi.org");
 190MODULE_DESCRIPTION("Comedi helper for amplc_pc236 and amplc_pci236");
 191MODULE_LICENSE("GPL");
 192