1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * comedi/drivers/dt2814.c 4 * Hardware driver for Data Translation DT2814 5 * 6 * COMEDI - Linux Control and Measurement Device Interface 7 * Copyright (C) 1998 David A. Schleef <ds@schleef.org> 8 */ 9 /* 10 * Driver: dt2814 11 * Description: Data Translation DT2814 12 * Author: ds 13 * Status: complete 14 * Devices: [Data Translation] DT2814 (dt2814) 15 * 16 * Configuration options: 17 * [0] - I/O port base address 18 * [1] - IRQ 19 * 20 * This card has 16 analog inputs multiplexed onto a 12 bit ADC. There 21 * is a minimally useful onboard clock. The base frequency for the 22 * clock is selected by jumpers, and the clock divider can be selected 23 * via programmed I/O. Unfortunately, the clock divider can only be 24 * a power of 10, from 1 to 10^7, of which only 3 or 4 are useful. In 25 * addition, the clock does not seem to be very accurate. 26 */ 27 28 #include <linux/module.h> 29 #include <linux/interrupt.h> 30 #include <linux/comedi/comedidev.h> 31 #include <linux/delay.h> 32 33 #define DT2814_CSR 0 34 #define DT2814_DATA 1 35 36 /* 37 * flags 38 */ 39 40 #define DT2814_FINISH 0x80 41 #define DT2814_ERR 0x40 42 #define DT2814_BUSY 0x20 43 #define DT2814_ENB 0x10 44 #define DT2814_CHANMASK 0x0f 45 46 #define DT2814_TIMEOUT 10 47 #define DT2814_MAX_SPEED 100000 /* Arbitrary 10 khz limit */ 48 49 static int dt2814_ai_notbusy(struct comedi_device *dev, 50 struct comedi_subdevice *s, 51 struct comedi_insn *insn, 52 unsigned long context) 53 { 54 unsigned int status; 55 56 status = inb(dev->iobase + DT2814_CSR); 57 if (context) 58 *(unsigned int *)context = status; 59 if (status & DT2814_BUSY) 60 return -EBUSY; 61 return 0; 62 } 63 64 static int dt2814_ai_clear(struct comedi_device *dev) 65 { 66 unsigned int status = 0; 67 int ret; 68 69 /* Wait until not busy and get status register value. */ 70 ret = comedi_timeout(dev, NULL, NULL, dt2814_ai_notbusy, 71 (unsigned long)&status); 72 if (ret) 73 return ret; 74 75 if (status & (DT2814_FINISH | DT2814_ERR)) { 76 /* 77 * There unread data, or the error flag is set. 78 * Read the data register twice to clear the condition. 79 */ 80 inb(dev->iobase + DT2814_DATA); 81 inb(dev->iobase + DT2814_DATA); 82 } 83 return 0; 84 } 85 86 static int dt2814_ai_eoc(struct comedi_device *dev, 87 struct comedi_subdevice *s, 88 struct comedi_insn *insn, 89 unsigned long context) 90 { 91 unsigned int status; 92 93 status = inb(dev->iobase + DT2814_CSR); 94 if (status & DT2814_FINISH) 95 return 0; 96 return -EBUSY; 97 } 98 99 static int dt2814_ai_insn_read(struct comedi_device *dev, 100 struct comedi_subdevice *s, 101 struct comedi_insn *insn, unsigned int *data) 102 { 103 int n, hi, lo; 104 int chan; 105 int ret; 106 107 dt2814_ai_clear(dev); /* clear stale data or error */ 108 for (n = 0; n < insn->n; n++) { 109 chan = CR_CHAN(insn->chanspec); 110 111 outb(chan, dev->iobase + DT2814_CSR); 112 113 ret = comedi_timeout(dev, s, insn, dt2814_ai_eoc, 0); 114 if (ret) 115 return ret; 116 117 hi = inb(dev->iobase + DT2814_DATA); 118 lo = inb(dev->iobase + DT2814_DATA); 119 120 data[n] = (hi << 4) | (lo >> 4); 121 } 122 123 return n; 124 } 125 126 static int dt2814_ns_to_timer(unsigned int *ns, unsigned int flags) 127 { 128 int i; 129 unsigned int f; 130 131 /* XXX ignores flags */ 132 133 f = 10000; /* ns */ 134 for (i = 0; i < 8; i++) { 135 if ((2 * (*ns)) < (f * 11)) 136 break; 137 f *= 10; 138 } 139 140 *ns = f; 141 142 return i; 143 } 144 145 static int dt2814_ai_cmdtest(struct comedi_device *dev, 146 struct comedi_subdevice *s, struct comedi_cmd *cmd) 147 { 148 int err = 0; 149 unsigned int arg; 150 151 /* Step 1 : check if triggers are trivially valid */ 152 153 err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW); 154 err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER); 155 err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW); 156 err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); 157 err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE); 158 159 if (err) 160 return 1; 161 162 /* Step 2a : make sure trigger sources are unique */ 163 164 err |= comedi_check_trigger_is_unique(cmd->stop_src); 165 166 /* Step 2b : and mutually compatible */ 167 168 if (err) 169 return 2; 170 171 /* Step 3: check if arguments are trivially valid */ 172 173 err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0); 174 175 err |= comedi_check_trigger_arg_max(&cmd->scan_begin_arg, 1000000000); 176 err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, 177 DT2814_MAX_SPEED); 178 179 err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, 180 cmd->chanlist_len); 181 182 if (cmd->stop_src == TRIG_COUNT) 183 err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 2); 184 else /* TRIG_NONE */ 185 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0); 186 187 if (err) 188 return 3; 189 190 /* step 4: fix up any arguments */ 191 192 arg = cmd->scan_begin_arg; 193 dt2814_ns_to_timer(&arg, cmd->flags); 194 err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); 195 196 if (err) 197 return 4; 198 199 return 0; 200 } 201 202 static int dt2814_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) 203 { 204 struct comedi_cmd *cmd = &s->async->cmd; 205 int chan; 206 int trigvar; 207 208 dt2814_ai_clear(dev); /* clear stale data or error */ 209 trigvar = dt2814_ns_to_timer(&cmd->scan_begin_arg, cmd->flags); 210 211 chan = CR_CHAN(cmd->chanlist[0]); 212 213 outb(chan | DT2814_ENB | (trigvar << 5), dev->iobase + DT2814_CSR); 214 215 return 0; 216 } 217 218 static int dt2814_ai_cancel(struct comedi_device *dev, 219 struct comedi_subdevice *s) 220 { 221 unsigned int status; 222 unsigned long flags; 223 224 spin_lock_irqsave(&dev->spinlock, flags); 225 status = inb(dev->iobase + DT2814_CSR); 226 if (status & DT2814_ENB) { 227 /* 228 * Clear the timed trigger enable bit. 229 * 230 * Note: turning off timed mode triggers another 231 * sample. This will be mopped up by the calls to 232 * dt2814_ai_clear(). 233 */ 234 outb(status & DT2814_CHANMASK, dev->iobase + DT2814_CSR); 235 } 236 spin_unlock_irqrestore(&dev->spinlock, flags); 237 return 0; 238 } 239 240 static irqreturn_t dt2814_interrupt(int irq, void *d) 241 { 242 struct comedi_device *dev = d; 243 struct comedi_subdevice *s = dev->read_subdev; 244 struct comedi_async *async; 245 unsigned int lo, hi; 246 unsigned short data; 247 unsigned int status; 248 249 if (!dev->attached) { 250 dev_err(dev->class_dev, "spurious interrupt\n"); 251 return IRQ_HANDLED; 252 } 253 254 async = s->async; 255 256 spin_lock(&dev->spinlock); 257 258 status = inb(dev->iobase + DT2814_CSR); 259 if (!(status & DT2814_ENB)) { 260 /* Timed acquisition not enabled. Nothing to do. */ 261 spin_unlock(&dev->spinlock); 262 return IRQ_HANDLED; 263 } 264 265 if (!(status & (DT2814_FINISH | DT2814_ERR))) { 266 /* Spurious interrupt? */ 267 spin_unlock(&dev->spinlock); 268 return IRQ_HANDLED; 269 } 270 271 /* Read data or clear error. */ 272 hi = inb(dev->iobase + DT2814_DATA); 273 lo = inb(dev->iobase + DT2814_DATA); 274 275 data = (hi << 4) | (lo >> 4); 276 277 if (status & DT2814_ERR) { 278 async->events |= COMEDI_CB_ERROR; 279 } else { 280 comedi_buf_write_samples(s, &data, 1); 281 if (async->cmd.stop_src == TRIG_COUNT && 282 async->scans_done >= async->cmd.stop_arg) { 283 async->events |= COMEDI_CB_EOA; 284 } 285 } 286 if (async->events & COMEDI_CB_CANCEL_MASK) { 287 /* 288 * Disable timed mode. 289 * 290 * Note: turning off timed mode triggers another 291 * sample. This will be mopped up by the calls to 292 * dt2814_ai_clear(). 293 */ 294 outb(status & DT2814_CHANMASK, dev->iobase + DT2814_CSR); 295 } 296 297 spin_unlock(&dev->spinlock); 298 299 comedi_handle_events(dev, s); 300 return IRQ_HANDLED; 301 } 302 303 static int dt2814_attach(struct comedi_device *dev, struct comedi_devconfig *it) 304 { 305 struct comedi_subdevice *s; 306 int ret; 307 308 ret = comedi_request_region(dev, it->options[0], 0x2); 309 if (ret) 310 return ret; 311 312 outb(0, dev->iobase + DT2814_CSR); 313 if (dt2814_ai_clear(dev)) { 314 dev_err(dev->class_dev, "reset error (fatal)\n"); 315 return -EIO; 316 } 317 318 if (it->options[1]) { 319 ret = request_irq(it->options[1], dt2814_interrupt, 0, 320 dev->board_name, dev); 321 if (ret == 0) 322 dev->irq = it->options[1]; 323 } 324 325 ret = comedi_alloc_subdevices(dev, 1); 326 if (ret) 327 return ret; 328 329 s = &dev->subdevices[0]; 330 s->type = COMEDI_SUBD_AI; 331 s->subdev_flags = SDF_READABLE | SDF_GROUND; 332 s->n_chan = 16; /* XXX */ 333 s->insn_read = dt2814_ai_insn_read; 334 s->maxdata = 0xfff; 335 s->range_table = &range_unknown; /* XXX */ 336 if (dev->irq) { 337 dev->read_subdev = s; 338 s->subdev_flags |= SDF_CMD_READ; 339 s->len_chanlist = 1; 340 s->do_cmd = dt2814_ai_cmd; 341 s->do_cmdtest = dt2814_ai_cmdtest; 342 s->cancel = dt2814_ai_cancel; 343 } 344 345 return 0; 346 } 347 348 static void dt2814_detach(struct comedi_device *dev) 349 { 350 if (dev->irq) { 351 /* 352 * An extra conversion triggered on termination of an 353 * asynchronous command may still be in progress. Wait for 354 * it to finish and clear the data or error status. 355 */ 356 dt2814_ai_clear(dev); 357 } 358 comedi_legacy_detach(dev); 359 } 360 361 static struct comedi_driver dt2814_driver = { 362 .driver_name = "dt2814", 363 .module = THIS_MODULE, 364 .attach = dt2814_attach, 365 .detach = dt2814_detach, 366 }; 367 module_comedi_driver(dt2814_driver); 368 369 MODULE_AUTHOR("Comedi https://www.comedi.org"); 370 MODULE_DESCRIPTION("Comedi low-level driver"); 371 MODULE_LICENSE("GPL"); 372