pcmda12.c revision 214e7b5c8281bf41238f575128e4fec5652ed797
1/* 2 comedi/drivers/pcmda12.c 3 Driver for Winsystems PC-104 based PCM-D/A-12 8-channel AO board. 4 5 COMEDI - Linux Control and Measurement Device Interface 6 Copyright (C) 2006 Calin A. Culianu <calin@ajvar.org> 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21*/ 22/* 23Driver: pcmda12 24Description: A driver for the Winsystems PCM-D/A-12 25Devices: [Winsystems] PCM-D/A-12 (pcmda12) 26Author: Calin Culianu <calin@ajvar.org> 27Updated: Fri, 13 Jan 2006 12:01:01 -0500 28Status: works 29 30A driver for the relatively straightforward-to-program PCM-D/A-12. 31This board doesn't support commands, and the only way to set its 32analog output range is to jumper the board. As such, 33comedi_data_write() ignores the range value specified. 34 35The board uses 16 consecutive I/O addresses starting at the I/O port 36base address. Each address corresponds to the LSB then MSB of a 37particular channel from 0-7. 38 39Note that the board is not ISA-PNP capable and thus 40needs the I/O port comedi_config parameter. 41 42Note that passing a nonzero value as the second config option will 43enable "simultaneous xfer" mode for this board, in which AO writes 44will not take effect until a subsequent read of any AO channel. This 45is so that one can speed up programming by preloading all AO registers 46with values before simultaneously setting them to take effect with one 47read command. 48 49Configuration Options: 50 [0] - I/O port base address 51 [1] - Do Simultaneous Xfer (see description) 52*/ 53 54#include "../comedidev.h" 55 56#include <linux/pci.h> /* for PCI devices */ 57 58#define SDEV_NO ((int)(s - dev->subdevices)) 59#define CHANS 8 60#define IOSIZE 16 61#define LSB(x) ((unsigned char)((x) & 0xff)) 62#define MSB(x) ((unsigned char)((((unsigned short)(x))>>8) & 0xff)) 63#define LSB_PORT(chan) (dev->iobase + (chan)*2) 64#define MSB_PORT(chan) (LSB_PORT(chan)+1) 65#define BITS 12 66 67/* 68 * Bords 69 */ 70struct pcmda12_board { 71 const char *name; 72}; 73 74/* note these have no effect and are merely here for reference.. 75 these are configured by jumpering the board! */ 76static const struct comedi_lrange pcmda12_ranges = { 77 3, 78 { 79 UNI_RANGE(5), UNI_RANGE(10), BIP_RANGE(5) 80 } 81}; 82 83static const struct pcmda12_board pcmda12_boards[] = { 84 { 85 .name = "pcmda12", 86 }, 87}; 88 89/* 90 * Useful for shorthand access to the particular board structure 91 */ 92#define thisboard ((const struct pcmda12_board *)dev->board_ptr) 93 94struct pcmda12_private { 95 96 unsigned int ao_readback[CHANS]; 97 int simultaneous_xfer_mode; 98}; 99 100 101#define devpriv ((struct pcmda12_private *)(dev->private)) 102 103/* 104 * The struct comedi_driver structure tells the Comedi core module 105 * which functions to call to configure/deconfigure (attach/detach) 106 * the board, and also about the kernel module that contains 107 * the device code. 108 */ 109static int pcmda12_attach(struct comedi_device *dev, struct comedi_devconfig *it); 110static int pcmda12_detach(struct comedi_device *dev); 111 112static void zero_chans(struct comedi_device *dev); 113 114static struct comedi_driver driver = { 115 .driver_name = "pcmda12", 116 .module = THIS_MODULE, 117 .attach = pcmda12_attach, 118 .detach = pcmda12_detach, 119/* It is not necessary to implement the following members if you are 120 * writing a driver for a ISA PnP or PCI card */ 121 /* Most drivers will support multiple types of boards by 122 * having an array of board structures. These were defined 123 * in pcmda12_boards[] above. Note that the element 'name' 124 * was first in the structure -- Comedi uses this fact to 125 * extract the name of the board without knowing any details 126 * about the structure except for its length. 127 * When a device is attached (by comedi_config), the name 128 * of the device is given to Comedi, and Comedi tries to 129 * match it by going through the list of board names. If 130 * there is a match, the address of the pointer is put 131 * into dev->board_ptr and driver->attach() is called. 132 * 133 * Note that these are not necessary if you can determine 134 * the type of board in software. ISA PnP, PCI, and PCMCIA 135 * devices are such boards. 136 */ 137 .board_name = &pcmda12_boards[0].name, 138 .offset = sizeof(struct pcmda12_board), 139 .num_names = ARRAY_SIZE(pcmda12_boards), 140}; 141 142static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s, 143 struct comedi_insn *insn, unsigned int *data); 144static int ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 145 struct comedi_insn *insn, unsigned int *data); 146 147/* 148 * Attach is called by the Comedi core to configure the driver 149 * for a particular board. If you specified a board_name array 150 * in the driver structure, dev->board_ptr contains that 151 * address. 152 */ 153static int pcmda12_attach(struct comedi_device *dev, struct comedi_devconfig *it) 154{ 155 struct comedi_subdevice *s; 156 unsigned long iobase; 157 158 iobase = it->options[0]; 159 printk("comedi%d: %s: io: %lx %s ", dev->minor, driver.driver_name, 160 iobase, it->options[1] ? "simultaneous xfer mode enabled" : ""); 161 162 if (!request_region(iobase, IOSIZE, driver.driver_name)) { 163 printk("I/O port conflict\n"); 164 return -EIO; 165 } 166 dev->iobase = iobase; 167 168/* 169 * Initialize dev->board_name. Note that we can use the "thisboard" 170 * macro now, since we just initialized it in the last line. 171 */ 172 dev->board_name = thisboard->name; 173 174/* 175 * Allocate the private structure area. alloc_private() is a 176 * convenient macro defined in comedidev.h. 177 */ 178 if (alloc_private(dev, sizeof(struct pcmda12_private)) < 0) { 179 printk("cannot allocate private data structure\n"); 180 return -ENOMEM; 181 } 182 183 devpriv->simultaneous_xfer_mode = it->options[1]; 184 185 /* 186 * Allocate the subdevice structures. alloc_subdevice() is a 187 * convenient macro defined in comedidev.h. 188 * 189 * Allocate 2 subdevs (32 + 16 DIO lines) or 3 32 DIO subdevs for the 190 * 96-channel version of the board. 191 */ 192 if (alloc_subdevices(dev, 1) < 0) { 193 printk("cannot allocate subdevice data structures\n"); 194 return -ENOMEM; 195 } 196 197 s = dev->subdevices; 198 s->private = NULL; 199 s->maxdata = (0x1 << BITS) - 1; 200 s->range_table = &pcmda12_ranges; 201 s->type = COMEDI_SUBD_AO; 202 s->subdev_flags = SDF_READABLE | SDF_WRITABLE; 203 s->n_chan = CHANS; 204 s->insn_write = &ao_winsn; 205 s->insn_read = &ao_rinsn; 206 207 zero_chans(dev); /* clear out all the registers, basically */ 208 209 printk("attached\n"); 210 211 return 1; 212} 213 214/* 215 * _detach is called to deconfigure a device. It should deallocate 216 * resources. 217 * This function is also called when _attach() fails, so it should be 218 * careful not to release resources that were not necessarily 219 * allocated by _attach(). dev->private and dev->subdevices are 220 * deallocated automatically by the core. 221 */ 222static int pcmda12_detach(struct comedi_device *dev) 223{ 224 printk("comedi%d: %s: remove\n", dev->minor, driver.driver_name); 225 if (dev->iobase) 226 release_region(dev->iobase, IOSIZE); 227 return 0; 228} 229 230static void zero_chans(struct comedi_device *dev) 231{ /* sets up an 232 ASIC chip to defaults */ 233 int i; 234 for (i = 0; i < CHANS; ++i) { 235/* /\* do this as one instruction?? *\/ */ 236/* outw(0, LSB_PORT(chan)); */ 237 outb(0, LSB_PORT(i)); 238 outb(0, MSB_PORT(i)); 239 } 240 inb(LSB_PORT(0)); /* update chans. */ 241} 242 243static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s, 244 struct comedi_insn *insn, unsigned int *data) 245{ 246 int i; 247 int chan = CR_CHAN(insn->chanspec); 248 249 /* Writing a list of values to an AO channel is probably not 250 * very useful, but that's how the interface is defined. */ 251 for (i = 0; i < insn->n; ++i) { 252 253/* /\* do this as one instruction?? *\/ */ 254/* outw(data[i], LSB_PORT(chan)); */ 255 256 /* Need to do this as two instructions due to 8-bit bus?? */ 257 /* first, load the low byte */ 258 outb(LSB(data[i]), LSB_PORT(chan)); 259 /* next, write the high byte */ 260 outb(MSB(data[i]), MSB_PORT(chan)); 261 262 /* save shadow register */ 263 devpriv->ao_readback[chan] = data[i]; 264 265 if (!devpriv->simultaneous_xfer_mode) 266 inb(LSB_PORT(chan)); 267 } 268 269 /* return the number of samples written */ 270 return i; 271} 272 273/* AO subdevices should have a read insn as well as a write insn. 274 275 Usually this means copying a value stored in devpriv->ao_readback. 276 However, since this driver supports simultaneous xfer then sometimes 277 this function actually accomplishes work. 278 279 Simultaneaous xfer mode is accomplished by loading ALL the values 280 you want for AO in all the channels, then READing off one of the AO 281 registers to initiate the instantaneous simultaneous update of all 282 DAC outputs, which makes all AO channels update simultaneously. 283 This is useful for some control applications, I would imagine. 284*/ 285static int ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 286 struct comedi_insn *insn, unsigned int *data) 287{ 288 int i; 289 int chan = CR_CHAN(insn->chanspec); 290 291 for (i = 0; i < insn->n; i++) { 292 if (devpriv->simultaneous_xfer_mode) 293 inb(LSB_PORT(chan)); 294 /* read back shadow register */ 295 data[i] = devpriv->ao_readback[chan]; 296 } 297 298 return i; 299} 300 301/* 302 * A convenient macro that defines init_module() and cleanup_module(), 303 * as necessary. 304 */ 305COMEDI_INITCLEANUP(driver); 306