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. <https://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#include <linux/comedi/comedidev.h>
15#include <linux/comedi/comedi_8255.h>
16
17#include "amplc_pc236.h"
18
19static void pc236_intr_update(struct comedi_device *dev, bool enable)
20{
21 const struct pc236_board *board = dev->board_ptr;
22 struct pc236_private *devpriv = dev->private;
23 unsigned long flags;
24
25 spin_lock_irqsave(&dev->spinlock, flags);
26 devpriv->enable_irq = enable;
27 if (board->intr_update_cb)
28 board->intr_update_cb(dev, enable);
29 spin_unlock_irqrestore(lock: &dev->spinlock, flags);
30}
31
32/*
33 * This function is called when an interrupt occurs to check whether
34 * the interrupt has been marked as enabled and was generated by the
35 * board. If so, the function prepares the hardware for the next
36 * interrupt.
37 * Returns false if the interrupt should be ignored.
38 */
39static bool pc236_intr_check(struct comedi_device *dev)
40{
41 const struct pc236_board *board = dev->board_ptr;
42 struct pc236_private *devpriv = dev->private;
43 bool retval = false;
44 unsigned long flags;
45
46 spin_lock_irqsave(&dev->spinlock, flags);
47 if (devpriv->enable_irq) {
48 if (board->intr_chk_clr_cb)
49 retval = board->intr_chk_clr_cb(dev);
50 else
51 retval = true;
52 }
53 spin_unlock_irqrestore(lock: &dev->spinlock, flags);
54
55 return retval;
56}
57
58static int pc236_intr_insn(struct comedi_device *dev,
59 struct comedi_subdevice *s, struct comedi_insn *insn,
60 unsigned int *data)
61{
62 data[1] = 0;
63 return insn->n;
64}
65
66static int pc236_intr_cmdtest(struct comedi_device *dev,
67 struct comedi_subdevice *s,
68 struct comedi_cmd *cmd)
69{
70 int err = 0;
71
72 /* Step 1 : check if triggers are trivially valid */
73
74 err |= comedi_check_trigger_src(src: &cmd->start_src, TRIG_NOW);
75 err |= comedi_check_trigger_src(src: &cmd->scan_begin_src, TRIG_EXT);
76 err |= comedi_check_trigger_src(src: &cmd->convert_src, TRIG_FOLLOW);
77 err |= comedi_check_trigger_src(src: &cmd->scan_end_src, TRIG_COUNT);
78 err |= comedi_check_trigger_src(src: &cmd->stop_src, TRIG_NONE);
79
80 if (err)
81 return 1;
82
83 /* Step 2a : make sure trigger sources are unique */
84 /* Step 2b : and mutually compatible */
85
86 /* Step 3: check it arguments are trivially valid */
87
88 err |= comedi_check_trigger_arg_is(arg: &cmd->start_arg, val: 0);
89 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_begin_arg, val: 0);
90 err |= comedi_check_trigger_arg_is(arg: &cmd->convert_arg, val: 0);
91 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_end_arg,
92 val: cmd->chanlist_len);
93 err |= comedi_check_trigger_arg_is(arg: &cmd->stop_arg, val: 0);
94
95 if (err)
96 return 3;
97
98 /* Step 4: fix up any arguments */
99
100 /* Step 5: check channel list if it exists */
101
102 return 0;
103}
104
105static int pc236_intr_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
106{
107 pc236_intr_update(dev, enable: true);
108
109 return 0;
110}
111
112static int pc236_intr_cancel(struct comedi_device *dev,
113 struct comedi_subdevice *s)
114{
115 pc236_intr_update(dev, enable: false);
116
117 return 0;
118}
119
120static irqreturn_t pc236_interrupt(int irq, void *d)
121{
122 struct comedi_device *dev = d;
123 struct comedi_subdevice *s = dev->read_subdev;
124 bool handled;
125
126 handled = pc236_intr_check(dev);
127 if (dev->attached && handled) {
128 unsigned short val = 0;
129
130 comedi_buf_write_samples(s, data: &val, nsamples: 1);
131 comedi_handle_events(dev, s);
132 }
133 return IRQ_RETVAL(handled);
134}
135
136int amplc_pc236_common_attach(struct comedi_device *dev, unsigned long iobase,
137 unsigned int irq, unsigned long req_irq_flags)
138{
139 struct comedi_subdevice *s;
140 int ret;
141
142 dev->iobase = iobase;
143
144 ret = comedi_alloc_subdevices(dev, num_subdevices: 2);
145 if (ret)
146 return ret;
147
148 s = &dev->subdevices[0];
149 /* digital i/o subdevice (8255) */
150 ret = subdev_8255_io_init(dev, s, regbase: 0x00);
151 if (ret)
152 return ret;
153
154 s = &dev->subdevices[1];
155 dev->read_subdev = s;
156 s->type = COMEDI_SUBD_UNUSED;
157 pc236_intr_update(dev, enable: false);
158 if (irq) {
159 if (request_irq(irq, handler: pc236_interrupt, flags: req_irq_flags,
160 name: dev->board_name, dev) >= 0) {
161 dev->irq = irq;
162 s->type = COMEDI_SUBD_DI;
163 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
164 s->n_chan = 1;
165 s->maxdata = 1;
166 s->range_table = &range_digital;
167 s->insn_bits = pc236_intr_insn;
168 s->len_chanlist = 1;
169 s->do_cmdtest = pc236_intr_cmdtest;
170 s->do_cmd = pc236_intr_cmd;
171 s->cancel = pc236_intr_cancel;
172 }
173 }
174
175 return 0;
176}
177EXPORT_SYMBOL_GPL(amplc_pc236_common_attach);
178
179static int __init amplc_pc236_common_init(void)
180{
181 return 0;
182}
183module_init(amplc_pc236_common_init);
184
185static void __exit amplc_pc236_common_exit(void)
186{
187}
188module_exit(amplc_pc236_common_exit);
189
190MODULE_AUTHOR("Comedi https://www.comedi.org");
191MODULE_DESCRIPTION("Comedi helper for amplc_pc236 and amplc_pci236");
192MODULE_LICENSE("GPL");
193

source code of linux/drivers/comedi/drivers/amplc_pc236_common.c