--- /dev/null
+/*
+ comedi/drivers/ni_at_a2150.c
+ Driver for National Instruments AT-A2150 boards
+ Copyright (C) 2001, 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
+
+ COMEDI - Linux Control and Measurement Device Interface
+ Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+************************************************************************
+*/
+/*
+Driver: ni_at_a2150
+Description: National Instruments AT-A2150
+Author: Frank Mori Hess
+Status: works
+Devices: [National Instruments] AT-A2150C (at_a2150c), AT-2150S (at_a2150s)
+
+If you want to ac couple the board's inputs, use AREF_OTHER.
+
+Configuration options:
+ [0] - I/O port base address
+ [1] - IRQ (optional, required for timed conversions)
+ [2] - DMA (optional, required for timed conversions)
+
+*/
+/*
+Yet another driver for obsolete hardware brought to you by Frank Hess.
+Testing and debugging help provided by Dave Andruczyk.
+
+This driver supports the boards:
+
+AT-A2150C
+AT-A2150S
+
+The only difference is their master clock frequencies.
+
+Options:
+ [0] - base io address
+ [1] - irq
+ [2] - dma channel
+
+References (from ftp://ftp.natinst.com/support/manuals):
+
+ 320360.pdf AT-A2150 User Manual
+
+TODO:
+
+analog level triggering
+TRIG_WAKE_EOS
+
+*/
+
+#include "../comedidev.h"
+
+#include <linux/ioport.h>
+#include <asm/dma.h>
+
+#include "8253.h"
+#include "comedi_fc.h"
+
+#define A2150_SIZE 28
+#define A2150_DMA_BUFFER_SIZE 0xff00 // size in bytes of dma buffer
+
+//#define A2150_DEBUG // enable debugging code
+#undef A2150_DEBUG // disable debugging code
+
+/* Registers and bits */
+#define CONFIG_REG 0x0
+#define CHANNEL_BITS(x) ((x) & 0x7)
+#define CHANNEL_MASK 0x7
+#define CLOCK_SELECT_BITS(x) (((x) & 0x3) << 3)
+#define CLOCK_DIVISOR_BITS(x) (((x) & 0x3) << 5)
+#define CLOCK_MASK (0xf << 3)
+#define ENABLE0_BIT 0x80 // enable (don't internally ground) channels 0 and 1
+#define ENABLE1_BIT 0x100 // enable (don't internally ground) channels 2 and 3
+#define AC0_BIT 0x200 // ac couple channels 0,1
+#define AC1_BIT 0x400 // ac couple channels 2,3
+#define APD_BIT 0x800 // analog power down
+#define DPD_BIT 0x1000 // digital power down
+#define TRIGGER_REG 0x2 // trigger config register
+#define POST_TRIGGER_BITS 0x2
+#define DELAY_TRIGGER_BITS 0x3
+#define HW_TRIG_EN 0x10 // enable hardware trigger
+#define FIFO_START_REG 0x6 // software start aquistion trigger
+#define FIFO_RESET_REG 0x8 // clears fifo + fifo flags
+#define FIFO_DATA_REG 0xa // read data
+#define DMA_TC_CLEAR_REG 0xe // clear dma terminal count interrupt
+#define STATUS_REG 0x12 // read only
+#define FNE_BIT 0x1 // fifo not empty
+#define OVFL_BIT 0x8 // fifo overflow
+#define EDAQ_BIT 0x10 // end of aquisition interrupt
+#define DCAL_BIT 0x20 // offset calibration in progress
+#define INTR_BIT 0x40 // interrupt has occured
+#define DMA_TC_BIT 0x80 // dma terminal count interrupt has occured
+#define ID_BITS(x) (((x) >> 8) & 0x3)
+#define IRQ_DMA_CNTRL_REG 0x12 // write only
+#define DMA_CHAN_BITS(x) ((x) & 0x7) // sets dma channel
+#define DMA_EN_BIT 0x8 // enables dma
+#define IRQ_LVL_BITS(x) (((x) & 0xf) << 4) // sets irq level
+#define FIFO_INTR_EN_BIT 0x100 // enable fifo interrupts
+#define FIFO_INTR_FHF_BIT 0x200 // interrupt fifo half full
+#define DMA_INTR_EN_BIT 0x800 // enable interrupt on dma terminal count
+#define DMA_DEM_EN_BIT 0x1000 // enables demand mode dma
+#define I8253_BASE_REG 0x14
+#define I8253_MODE_REG 0x17
+#define HW_COUNT_DISABLE 0x30 // disable hardware counting of conversions
+
+typedef struct a2150_board_struct {
+ const char *name;
+ int clock[4]; // master clock periods, in nanoseconds
+ int num_clocks; // number of available master clock speeds
+ int ai_speed; // maximum conversion rate in nanoseconds
+} a2150_board;
+
+//analog input range
+static const comedi_lrange range_a2150 = {
+ 1,
+ {
+ RANGE(-2.828, 2.828),
+ }
+};
+
+// enum must match board indices
+enum { a2150_c, a2150_s };
+static const a2150_board a2150_boards[] = {
+ {
+ name: "at-a2150c",
+ clock: {31250, 22676, 20833, 19531},
+ num_clocks:4,
+ ai_speed:19531,
+ },
+ {
+ name: "at-a2150s",
+ clock: {62500, 50000, 41667, 0},
+ num_clocks:3,
+ ai_speed:41667,
+ },
+};
+
+/*
+ * Useful for shorthand access to the particular board structure
+ */
+#define thisboard ((const a2150_board *)dev->board_ptr)
+
+typedef struct {
+ volatile unsigned int count; /* number of data points left to be taken */
+ unsigned int dma; // dma channel
+ s16 *dma_buffer; // dma buffer
+ unsigned int dma_transfer_size; // size in bytes of dma transfers
+ int irq_dma_bits; // irq/dma register bits
+ int config_bits; // config register bits
+} a2150_private;
+
+#define devpriv ((a2150_private *)dev->private)
+
+static int a2150_attach(comedi_device * dev, comedi_devconfig * it);
+static int a2150_detach(comedi_device * dev);
+static int a2150_cancel(comedi_device * dev, comedi_subdevice * s);
+
+static comedi_driver driver_a2150 = {
+ driver_name:"ni_at_a2150",
+ module:THIS_MODULE,
+ attach:a2150_attach,
+ detach:a2150_detach,
+};
+
+static irqreturn_t a2150_interrupt(int irq, void *d PT_REGS_ARG);
+static int a2150_ai_cmdtest(comedi_device * dev, comedi_subdevice * s,
+ comedi_cmd * cmd);
+static int a2150_ai_cmd(comedi_device * dev, comedi_subdevice * s);
+static int a2150_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
+ comedi_insn * insn, lsampl_t * data);
+static int a2150_get_timing(comedi_device * dev, unsigned int *period,
+ int flags);
+static int a2150_probe(comedi_device * dev);
+static int a2150_set_chanlist(comedi_device * dev, unsigned int start_channel,
+ unsigned int num_channels);
+/*
+ * A convenient macro that defines init_module() and cleanup_module(),
+ * as necessary.
+ */
+COMEDI_INITCLEANUP(driver_a2150);
+
+#ifdef A2150_DEBUG
+
+static void ni_dump_regs(comedi_device * dev)
+{
+ rt_printk("config bits 0x%x\n", devpriv->config_bits);
+ rt_printk("irq dma bits 0x%x\n", devpriv->irq_dma_bits);
+ rt_printk("status bits 0x%x\n", inw(dev->iobase + STATUS_REG));
+}
+
+#endif
+
+/* interrupt service routine */
+static irqreturn_t a2150_interrupt(int irq, void *d PT_REGS_ARG)
+{
+ int i;
+ int status;
+ unsigned long flags;
+ comedi_device *dev = d;
+ comedi_subdevice *s = dev->read_subdev;
+ comedi_async *async;
+ comedi_cmd *cmd;
+ unsigned int max_points, num_points, residue, leftover;
+ sampl_t dpnt;
+ static const int sample_size = sizeof(devpriv->dma_buffer[0]);
+
+ if (dev->attached == 0) {
+ comedi_error(dev, "premature interrupt");
+ return IRQ_HANDLED;
+ }
+ // initialize async here to make sure s is not NULL
+ async = s->async;
+ async->events = 0;
+ cmd = &async->cmd;
+
+ status = inw(dev->iobase + STATUS_REG);
+
+ if ((status & INTR_BIT) == 0) {
+ comedi_error(dev, "spurious interrupt");
+ return IRQ_NONE;
+ }
+
+ if (status & OVFL_BIT) {
+ comedi_error(dev, "fifo overflow");
+ a2150_cancel(dev, s);
+ async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
+ }
+
+ if ((status & DMA_TC_BIT) == 0) {
+ comedi_error(dev, "caught non-dma interrupt? Aborting.");
+ a2150_cancel(dev, s);
+ async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
+ comedi_event(dev, s);
+ return IRQ_HANDLED;
+ }
+
+ flags = claim_dma_lock();
+ disable_dma(devpriv->dma);
+ /* clear flip-flop to make sure 2-byte registers for
+ * count and address get set correctly */
+ clear_dma_ff(devpriv->dma);
+
+ // figure out how many points to read
+ max_points = devpriv->dma_transfer_size / sample_size;
+ /* residue is the number of points left to be done on the dma
+ * transfer. It should always be zero at this point unless
+ * the stop_src is set to external triggering.
+ */
+ residue = get_dma_residue(devpriv->dma) / sample_size;
+ num_points = max_points - residue;
+ if (devpriv->count < num_points && cmd->stop_src == TRIG_COUNT)
+ num_points = devpriv->count;
+
+ // figure out how many points will be stored next time
+ leftover = 0;
+ if (cmd->stop_src == TRIG_NONE) {
+ leftover = devpriv->dma_transfer_size / sample_size;
+ } else if (devpriv->count > max_points) {
+ leftover = devpriv->count - max_points;
+ if (leftover > max_points)
+ leftover = max_points;
+ }
+ /* there should only be a residue if collection was stopped by having
+ * the stop_src set to an external trigger, in which case there
+ * will be no more data
+ */
+ if (residue)
+ leftover = 0;
+
+ for (i = 0; i < num_points; i++) {
+ /* write data point to comedi buffer */
+ dpnt = devpriv->dma_buffer[i];
+ // convert from 2's complement to unsigned coding
+ dpnt ^= 0x8000;
+ cfc_write_to_buffer(s, dpnt);
+ if (cmd->stop_src == TRIG_COUNT) {
+ if (--devpriv->count == 0) { /* end of acquisition */
+ a2150_cancel(dev, s);
+ async->events |= COMEDI_CB_EOA;
+ break;
+ }
+ }
+ }
+ // re-enable dma
+ if (leftover) {
+ set_dma_addr(devpriv->dma, virt_to_bus(devpriv->dma_buffer));
+ set_dma_count(devpriv->dma, leftover * sample_size);
+ enable_dma(devpriv->dma);
+ }
+ release_dma_lock(flags);
+
+ async->events |= COMEDI_CB_BLOCK;
+
+ comedi_event(dev, s);
+
+ /* clear interrupt */
+ outw(0x00, dev->iobase + DMA_TC_CLEAR_REG);
+
+ return IRQ_HANDLED;
+}
+
+// probes board type, returns offset
+static int a2150_probe(comedi_device * dev)
+{
+ int status = inw(dev->iobase + STATUS_REG);
+ return ID_BITS(status);
+}
+
+static int a2150_attach(comedi_device * dev, comedi_devconfig * it)
+{
+ comedi_subdevice *s;
+ unsigned long iobase = it->options[0];
+ unsigned int irq = it->options[1];
+ unsigned int dma = it->options[2];
+ static const int timeout = 2000;
+ int i;
+
+ printk("comedi%d: %s: io 0x%lx", dev->minor, driver_a2150.driver_name,
+ iobase);
+ if (irq) {
+ printk(", irq %u", irq);
+ } else {
+ printk(", no irq");
+ }
+ if (dma) {
+ printk(", dma %u", dma);
+ } else {
+ printk(", no dma");
+ }
+ printk("\n");
+
+ /* allocate and initialize dev->private */
+ if (alloc_private(dev, sizeof(a2150_private)) < 0)
+ return -ENOMEM;
+
+ if (iobase == 0) {
+ printk(" io base address required\n");
+ return -EINVAL;
+ }
+
+ /* check if io addresses are available */
+ if (!request_region(iobase, A2150_SIZE, driver_a2150.driver_name)) {
+ printk(" I/O port conflict\n");
+ return -EIO;
+ }
+ dev->iobase = iobase;
+
+ /* grab our IRQ */
+ if (irq) {
+ // check that irq is supported
+ if (irq < 3 || irq == 8 || irq == 13 || irq > 15) {
+ printk(" invalid irq line %u\n", irq);
+ return -EINVAL;
+ }
+ if (comedi_request_irq(irq, a2150_interrupt, 0,
+ driver_a2150.driver_name, dev)) {
+ printk("unable to allocate irq %u\n", irq);
+ return -EINVAL;
+ }
+ devpriv->irq_dma_bits |= IRQ_LVL_BITS(irq);
+ dev->irq = irq;
+ }
+ // initialize dma
+ if (dma) {
+ if (dma == 4 || dma > 7) {
+ printk(" invalid dma channel %u\n", dma);
+ return -EINVAL;
+ }
+ if (request_dma(dma, driver_a2150.driver_name)) {
+ printk(" failed to allocate dma channel %u\n", dma);
+ return -EINVAL;
+ }
+ devpriv->dma = dma;
+ devpriv->dma_buffer =
+ kmalloc(A2150_DMA_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
+ if (devpriv->dma_buffer == NULL)
+ return -ENOMEM;
+
+ disable_dma(dma);
+ set_dma_mode(dma, DMA_MODE_READ);
+
+ devpriv->irq_dma_bits |= DMA_CHAN_BITS(dma);
+ }
+
+ dev->board_ptr = a2150_boards + a2150_probe(dev);
+ dev->board_name = thisboard->name;
+
+ if (alloc_subdevices(dev, 1) < 0)
+ return -ENOMEM;
+
+ /* analog input subdevice */
+ s = dev->subdevices + 0;
+ dev->read_subdev = s;
+ s->type = COMEDI_SUBD_AI;
+ s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_OTHER | SDF_CMD_READ;
+ s->n_chan = 4;
+ s->len_chanlist = 4;
+ s->maxdata = 0xffff;
+ s->range_table = &range_a2150;
+ s->do_cmd = a2150_ai_cmd;
+ s->do_cmdtest = a2150_ai_cmdtest;
+ s->insn_read = a2150_ai_rinsn;
+ s->cancel = a2150_cancel;
+
+ /* need to do this for software counting of completed conversions, to
+ * prevent hardware count from stopping aquisition */
+ outw(HW_COUNT_DISABLE, dev->iobase + I8253_MODE_REG);
+
+ // set card's irq and dma levels
+ outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
+
+ // reset and sync adc clock circuitry
+ outw_p(DPD_BIT | APD_BIT, dev->iobase + CONFIG_REG);
+ outw_p(DPD_BIT, dev->iobase + CONFIG_REG);
+ // initialize configuration register
+ devpriv->config_bits = 0;
+ outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
+ // wait until offset calibration is done, then enable analog inputs
+ for (i = 0; i < timeout; i++) {
+ if ((DCAL_BIT & inw(dev->iobase + STATUS_REG)) == 0)
+ break;
+ comedi_udelay(1000);
+ }
+ if (i == timeout) {
+ printk(" timed out waiting for offset calibration to complete\n");
+ return -ETIME;
+ }
+ devpriv->config_bits |= ENABLE0_BIT | ENABLE1_BIT;
+ outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
+
+ return 0;
+};
+
+static int a2150_detach(comedi_device * dev)
+{
+ printk("comedi%d: %s: remove\n", dev->minor, driver_a2150.driver_name);
+
+ /* only free stuff if it has been allocated by _attach */
+ if (dev->iobase) {
+ // put board in power-down mode
+ outw(APD_BIT | DPD_BIT, dev->iobase + CONFIG_REG);
+ release_region(dev->iobase, A2150_SIZE);
+ }
+
+ if (dev->irq)
+ comedi_free_irq(dev->irq, dev);
+ if (devpriv) {
+ if (devpriv->dma)
+ free_dma(devpriv->dma);
+ if (devpriv->dma_buffer)
+ kfree(devpriv->dma_buffer);
+ }
+
+ return 0;
+};
+
+static int a2150_cancel(comedi_device * dev, comedi_subdevice * s)
+{
+ // disable dma on card
+ devpriv->irq_dma_bits &= ~DMA_INTR_EN_BIT & ~DMA_EN_BIT;
+ outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
+
+ // disable computer's dma
+ disable_dma(devpriv->dma);
+
+ // clear fifo and reset triggering circuitry
+ outw(0, dev->iobase + FIFO_RESET_REG);
+
+ return 0;
+}
+
+static int a2150_ai_cmdtest(comedi_device * dev, comedi_subdevice * s,
+ comedi_cmd * cmd)
+{
+ int err = 0;
+ int tmp;
+ int startChan;
+ int i;
+
+ /* step 1: make sure trigger sources are trivially valid */
+
+ tmp = cmd->start_src;
+ cmd->start_src &= TRIG_NOW | TRIG_EXT;
+ if (!cmd->start_src || tmp != cmd->start_src)
+ err++;
+
+ tmp = cmd->scan_begin_src;
+ cmd->scan_begin_src &= TRIG_TIMER;
+ if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
+ err++;
+
+ tmp = cmd->convert_src;
+ cmd->convert_src &= TRIG_NOW;
+ if (!cmd->convert_src || tmp != cmd->convert_src)
+ err++;
+
+ tmp = cmd->scan_end_src;
+ cmd->scan_end_src &= TRIG_COUNT;
+ if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
+ err++;
+
+ tmp = cmd->stop_src;
+ cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
+ if (!cmd->stop_src || tmp != cmd->stop_src)
+ err++;
+
+ if (err)
+ return 1;
+
+ /* step 2: make sure trigger sources are unique and mutually compatible */
+
+ if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
+ err++;
+ if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
+ err++;
+
+ if (err)
+ return 2;
+
+ /* step 3: make sure arguments are trivially compatible */
+
+ if (cmd->start_arg != 0) {
+ cmd->start_arg = 0;
+ err++;
+ }
+ if (cmd->convert_src == TRIG_TIMER) {
+ if (cmd->convert_arg < thisboard->ai_speed) {
+ cmd->convert_arg = thisboard->ai_speed;
+ err++;
+ }
+ }
+ if (!cmd->chanlist_len) {
+ cmd->chanlist_len = 1;
+ err++;
+ }
+ if (cmd->scan_end_arg != cmd->chanlist_len) {
+ cmd->scan_end_arg = cmd->chanlist_len;
+ err++;
+ }
+ if (cmd->stop_src == TRIG_COUNT) {
+ if (!cmd->stop_arg) {
+ cmd->stop_arg = 1;
+ err++;
+ }
+ } else { /* TRIG_NONE */
+ if (cmd->stop_arg != 0) {
+ cmd->stop_arg = 0;
+ err++;
+ }
+ }
+
+ if (err)
+ return 3;
+
+ /* step 4: fix up any arguments */
+
+ if (cmd->scan_begin_src == TRIG_TIMER) {
+ tmp = cmd->scan_begin_arg;
+ a2150_get_timing(dev, &cmd->scan_begin_arg, cmd->flags);
+ if (tmp != cmd->scan_begin_arg)
+ err++;
+ }
+
+ if (err)
+ return 4;
+
+ // check channel/gain list against card's limitations
+ if (cmd->chanlist) {
+ startChan = CR_CHAN(cmd->chanlist[0]);
+ for (i = 1; i < cmd->chanlist_len; i++) {
+ if (CR_CHAN(cmd->chanlist[i]) != (startChan + i)) {
+ comedi_error(dev,
+ "entries in chanlist must be consecutive channels, counting upwards\n");
+ err++;
+ }
+ }
+ if (cmd->chanlist_len == 2 && CR_CHAN(cmd->chanlist[0]) == 1) {
+ comedi_error(dev,
+ "length 2 chanlist must be channels 0,1 or channels 2,3");
+ err++;
+ }
+ if (cmd->chanlist_len == 3) {
+ comedi_error(dev,
+ "chanlist must have 1,2 or 4 channels");
+ err++;
+ }
+ if (CR_AREF(cmd->chanlist[0]) != CR_AREF(cmd->chanlist[1]) ||
+ CR_AREF(cmd->chanlist[2]) != CR_AREF(cmd->chanlist[3]))
+ {
+ comedi_error(dev,
+ "channels 0/1 and 2/3 must have the same analog reference");
+ err++;
+ }
+ }
+
+ if (err)
+ return 5;
+
+ return 0;
+}
+
+static int a2150_ai_cmd(comedi_device * dev, comedi_subdevice * s)
+{
+ comedi_async *async = s->async;
+ comedi_cmd *cmd = &async->cmd;
+ unsigned long lock_flags;
+ unsigned int old_config_bits = devpriv->config_bits;
+ unsigned int trigger_bits;
+
+ if (!dev->irq || !devpriv->dma) {
+ comedi_error(dev,
+ " irq and dma required, cannot do hardware conversions");
+ return -1;
+ }
+ if (cmd->flags & TRIG_RT) {
+ comedi_error(dev,
+ " dma incompatible with hard real-time interrupt (TRIG_RT), aborting");
+ return -1;
+ }
+ // clear fifo and reset triggering circuitry
+ outw(0, dev->iobase + FIFO_RESET_REG);
+
+ /* setup chanlist */
+ if (a2150_set_chanlist(dev, CR_CHAN(cmd->chanlist[0]),
+ cmd->chanlist_len) < 0)
+ return -1;
+
+ // setup ac/dc coupling
+ if (CR_AREF(cmd->chanlist[0]) == AREF_OTHER)
+ devpriv->config_bits |= AC0_BIT;
+ else
+ devpriv->config_bits &= ~AC0_BIT;
+ if (CR_AREF(cmd->chanlist[2]) == AREF_OTHER)
+ devpriv->config_bits |= AC1_BIT;
+ else
+ devpriv->config_bits &= ~AC1_BIT;
+
+ // setup timing
+ a2150_get_timing(dev, &cmd->scan_begin_arg, cmd->flags);
+
+ // send timing, channel, config bits
+ outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
+
+ // initialize number of samples remaining
+ devpriv->count = cmd->stop_arg * cmd->chanlist_len;
+
+ // enable computer's dma
+ lock_flags = claim_dma_lock();
+ disable_dma(devpriv->dma);
+ /* clear flip-flop to make sure 2-byte registers for
+ * count and address get set correctly */
+ clear_dma_ff(devpriv->dma);
+ set_dma_addr(devpriv->dma, virt_to_bus(devpriv->dma_buffer));
+ // set size of transfer to fill in 1/3 second
+#define ONE_THIRD_SECOND 333333333
+ devpriv->dma_transfer_size =
+ sizeof(devpriv->dma_buffer[0]) * cmd->chanlist_len *
+ ONE_THIRD_SECOND / cmd->scan_begin_arg;
+ if (devpriv->dma_transfer_size > A2150_DMA_BUFFER_SIZE)
+ devpriv->dma_transfer_size = A2150_DMA_BUFFER_SIZE;
+ if (devpriv->dma_transfer_size < sizeof(devpriv->dma_buffer[0]))
+ devpriv->dma_transfer_size = sizeof(devpriv->dma_buffer[0]);
+ devpriv->dma_transfer_size -=
+ devpriv->dma_transfer_size % sizeof(devpriv->dma_buffer[0]);
+ set_dma_count(devpriv->dma, devpriv->dma_transfer_size);
+ enable_dma(devpriv->dma);
+ release_dma_lock(lock_flags);
+
+ /* clear dma interrupt before enabling it, to try and get rid of that
+ * one spurious interrupt that has been happening */
+ outw(0x00, dev->iobase + DMA_TC_CLEAR_REG);
+
+ // enable dma on card
+ devpriv->irq_dma_bits |= DMA_INTR_EN_BIT | DMA_EN_BIT;
+ outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
+
+ // may need to wait 72 sampling periods if timing was changed
+ i8254_load(dev->iobase + I8253_BASE_REG, 0, 2, 72, 0);
+
+ // setup start triggering
+ trigger_bits = 0;
+ // decide if we need to wait 72 periods for valid data
+ if (cmd->start_src == TRIG_NOW &&
+ (old_config_bits & CLOCK_MASK) !=
+ (devpriv->config_bits & CLOCK_MASK)) {
+ // set trigger source to delay trigger
+ trigger_bits |= DELAY_TRIGGER_BITS;
+ } else {
+ // otherwise no delay
+ trigger_bits |= POST_TRIGGER_BITS;
+ }
+ // enable external hardware trigger
+ if (cmd->start_src == TRIG_EXT) {
+ trigger_bits |= HW_TRIG_EN;
+ } else if (cmd->start_src == TRIG_OTHER) {
+ // XXX add support for level/slope start trigger using TRIG_OTHER
+ comedi_error(dev, "you shouldn't see this?");
+ }
+ // send trigger config bits
+ outw(trigger_bits, dev->iobase + TRIGGER_REG);
+
+ // start aquisition for soft trigger
+ if (cmd->start_src == TRIG_NOW) {
+ outw(0, dev->iobase + FIFO_START_REG);
+ }
+#ifdef A2150_DEBUG
+ ni_dump_regs(dev);
+#endif
+
+ return 0;
+}
+
+static int a2150_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
+ comedi_insn * insn, lsampl_t * data)
+{
+ unsigned int i, n;
+ static const int timeout = 100000;
+ static const int filter_delay = 36;
+
+ // clear fifo and reset triggering circuitry
+ outw(0, dev->iobase + FIFO_RESET_REG);
+
+ /* setup chanlist */
+ if (a2150_set_chanlist(dev, CR_CHAN(insn->chanspec), 1) < 0)
+ return -1;
+
+ // set dc coupling
+ devpriv->config_bits &= ~AC0_BIT;
+ devpriv->config_bits &= ~AC1_BIT;
+
+ // send timing, channel, config bits
+ outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
+
+ // disable dma on card
+ devpriv->irq_dma_bits &= ~DMA_INTR_EN_BIT & ~DMA_EN_BIT;
+ outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
+
+ // setup start triggering
+ outw(0, dev->iobase + TRIGGER_REG);
+
+ // start aquisition for soft trigger
+ outw(0, dev->iobase + FIFO_START_REG);
+
+ /* there is a 35.6 sample delay for data to get through the antialias filter */
+ for (n = 0; n < filter_delay; n++) {
+ for (i = 0; i < timeout; i++) {
+ if (inw(dev->iobase + STATUS_REG) & FNE_BIT)
+ break;
+ comedi_udelay(1);
+ }
+ if (i == timeout) {
+ comedi_error(dev, "timeout");
+ return -ETIME;
+ }
+ inw(dev->iobase + FIFO_DATA_REG);
+ }
+
+ // read data
+ for (n = 0; n < insn->n; n++) {
+ for (i = 0; i < timeout; i++) {
+ if (inw(dev->iobase + STATUS_REG) & FNE_BIT)
+ break;
+ comedi_udelay(1);
+ }
+ if (i == timeout) {
+ comedi_error(dev, "timeout");
+ return -ETIME;
+ }
+#ifdef A2150_DEBUG
+ ni_dump_regs(dev);
+#endif
+ data[n] = inw(dev->iobase + FIFO_DATA_REG);
+#ifdef A2150_DEBUG
+ rt_printk(" data is %i\n", data[n]);
+#endif
+ data[n] ^= 0x8000;
+ }
+
+ // clear fifo and reset triggering circuitry
+ outw(0, dev->iobase + FIFO_RESET_REG);
+
+ return n;
+}
+
+/* sets bits in devpriv->clock_bits to nearest approximation of requested period,
+ * adjusts requested period to actual timing. */
+static int a2150_get_timing(comedi_device * dev, unsigned int *period,
+ int flags)
+{
+ int lub, glb, temp;
+ int lub_divisor_shift, lub_index, glb_divisor_shift, glb_index;
+ int i, j;
+
+ // initialize greatest lower and least upper bounds
+ lub_divisor_shift = 3;
+ lub_index = 0;
+ lub = thisboard->clock[lub_index] * (1 << lub_divisor_shift);
+ glb_divisor_shift = 0;
+ glb_index = thisboard->num_clocks - 1;
+ glb = thisboard->clock[glb_index] * (1 << glb_divisor_shift);
+
+ // make sure period is in available range
+ if (*period < glb)
+ *period = glb;
+ if (*period > lub)
+ *period = lub;
+
+ // we can multiply period by 1, 2, 4, or 8, using (1 << i)
+ for (i = 0; i < 4; i++) {
+ // there are a maximum of 4 master clocks
+ for (j = 0; j < thisboard->num_clocks; j++) {
+ // temp is the period in nanosec we are evaluating
+ temp = thisboard->clock[j] * (1 << i);
+ // if it is the best match yet
+ if (temp < lub && temp >= *period) {
+ lub_divisor_shift = i;
+ lub_index = j;
+ lub = temp;
+ }
+ if (temp > glb && temp <= *period) {
+ glb_divisor_shift = i;
+ glb_index = j;
+ glb = temp;
+ }
+ }
+ }
+ flags &= TRIG_ROUND_MASK;
+ switch (flags) {
+ case TRIG_ROUND_NEAREST:
+ default:
+ // if least upper bound is better approximation
+ if (lub - *period < *period - glb) {
+ *period = lub;
+ } else {
+ *period = glb;
+ }
+ break;
+ case TRIG_ROUND_UP:
+ *period = lub;
+ break;
+ case TRIG_ROUND_DOWN:
+ *period = glb;
+ break;
+ }
+
+ // set clock bits for config register appropriately
+ devpriv->config_bits &= ~CLOCK_MASK;
+ if (*period == lub) {
+ devpriv->config_bits |=
+ CLOCK_SELECT_BITS(lub_index) |
+ CLOCK_DIVISOR_BITS(lub_divisor_shift);
+ } else {
+ devpriv->config_bits |=
+ CLOCK_SELECT_BITS(glb_index) |
+ CLOCK_DIVISOR_BITS(glb_divisor_shift);
+ }
+
+ return 0;
+}
+
+static int a2150_set_chanlist(comedi_device * dev, unsigned int start_channel,
+ unsigned int num_channels)
+{
+ if (start_channel + num_channels > 4)
+ return -1;
+
+ devpriv->config_bits &= ~CHANNEL_MASK;
+
+ switch (num_channels) {
+ case 1:
+ devpriv->config_bits |= CHANNEL_BITS(0x4 | start_channel);
+ break;
+ case 2:
+ if (start_channel == 0) {
+ devpriv->config_bits |= CHANNEL_BITS(0x2);
+ } else if (start_channel == 2) {
+ devpriv->config_bits |= CHANNEL_BITS(0x3);
+ } else {
+ return -1;
+ }
+ break;
+ case 4:
+ devpriv->config_bits |= CHANNEL_BITS(0x1);
+ break;
+ default:
+ return -1;
+ break;
+ }
+
+ return 0;
+}