// SPDX-License-Identifier: GPL-2.0+
/*
* mpc624.c
* Hardware driver for a Micro/sys inc. MPC-624 PC/104 board
*
* COMEDI - Linux Control and Measurement Device Interface
* Copyright (C) 2000 David A. Schleef <[email protected]>
*/
/*
* Driver: mpc624
* Description: Micro/sys MPC-624 PC/104 board
* Devices: [Micro/sys] MPC-624 (mpc624)
* Author: Stanislaw Raczynski <[email protected]>
* Updated: Thu, 15 Sep 2005 12:01:18 +0200
* Status: working
*
* The Micro/sys MPC-624 board is based on the LTC2440 24-bit sigma-delta
* ADC chip.
*
* Subdevices supported by the driver:
* - Analog In: supported
* - Digital I/O: not supported
* - LEDs: not supported
* - EEPROM: not supported
*
* Configuration Options:
* [0] - I/O base address
* [1] - conversion rate
* Conversion rate RMS noise Effective Number Of Bits
* 0 3.52kHz 23uV 17
* 1 1.76kHz 3.5uV 20
* 2 880Hz 2uV 21.3
* 3 440Hz 1.4uV 21.8
* 4 220Hz 1uV 22.4
* 5 110Hz 750uV 22.9
* 6 55Hz 510nV 23.4
* 7 27.5Hz 375nV 24
* 8 13.75Hz 250nV 24.4
* 9 6.875Hz 200nV 24.6
* [2] - voltage range
* 0 -1.01V .. +1.01V
* 1 -10.1V .. +10.1V
*/
#include <linux/module.h>
#include <linux/comedi/comedidev.h>
#include <linux/delay.h>
/* Offsets of different ports */
#define MPC624_MASTER_CONTROL 0 /* not used */
#define MPC624_GNMUXCH 1 /* Gain, Mux, Channel of ADC */
#define MPC624_ADC 2 /* read/write to/from ADC */
#define MPC624_EE 3 /* read/write to/from serial EEPROM via I2C */
#define MPC624_LEDS 4 /* write to LEDs */
#define MPC624_DIO 5 /* read/write to/from digital I/O ports */
#define MPC624_IRQ_MASK 6 /* IRQ masking enable/disable */
/* Register bits' names */
#define MPC624_ADBUSY BIT(5)
#define MPC624_ADSDO BIT(4)
#define MPC624_ADFO BIT(3)
#define MPC624_ADCS BIT(2)
#define MPC624_ADSCK BIT(1)
#define MPC624_ADSDI BIT(0)
/* 32-bit output value bits' names */
#define MPC624_EOC_BIT BIT(31)
#define MPC624_DMY_BIT BIT(30)
#define MPC624_SGN_BIT BIT(29)
/* SDI Speed/Resolution Programming bits */
#define MPC624_OSR(x) (((x) & 0x1f) << 27)
#define MPC624_SPEED_3_52_KHZ MPC624_OSR(0x11)
#define MPC624_SPEED_1_76_KHZ MPC624_OSR(0x12)
#define MPC624_SPEED_880_HZ MPC624_OSR(0x13)
#define MPC624_SPEED_440_HZ MPC624_OSR(0x14)
#define MPC624_SPEED_220_HZ MPC624_OSR(0x15)
#define MPC624_SPEED_110_HZ MPC624_OSR(0x16)
#define MPC624_SPEED_55_HZ MPC624_OSR(0x17)
#define MPC624_SPEED_27_5_HZ MPC624_OSR(0x18)
#define MPC624_SPEED_13_75_HZ MPC624_OSR(0x19)
#define MPC624_SPEED_6_875_HZ MPC624_OSR(0x1f)
struct mpc624_private {
unsigned int ai_speed;
};
/* -------------------------------------------------------------------------- */
static const struct comedi_lrange range_mpc624_bipolar1 = {
1,
{
/* BIP_RANGE(1.01) this is correct, */
/* but my MPC-624 actually seems to have a range of 2.02 */
BIP_RANGE(2.02)
}
};
static const struct comedi_lrange range_mpc624_bipolar10 = {
1,
{
/* BIP_RANGE(10.1) this is correct, */
/* but my MPC-624 actually seems to have a range of 20.2 */
BIP_RANGE(20.2)
}
};
static unsigned int mpc624_ai_get_sample(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct mpc624_private *devpriv = dev->private;
unsigned int data_out = devpriv->ai_speed;
unsigned int data_in = 0;
unsigned int bit;
int i;
/* Start reading data */
udelay(1);
for (i = 0; i < 32; i++) {
/* Set the clock low */
outb(0, dev->iobase + MPC624_ADC);
udelay(1);
/* Set the ADSDI line for the next bit (send to MPC624) */
bit = (data_out & BIT(31)) ? MPC624_ADSDI : 0;
outb(bit, dev->iobase + MPC624_ADC);
udelay(1);
/* Set the clock high */
outb(MPC624_ADSCK | bit, dev->iobase + MPC624_ADC);
udelay(1);
/* Read ADSDO on high clock (receive from MPC624) */
data_in <<= 1;
data_in |= (inb(dev->iobase + MPC624_ADC) & MPC624_ADSDO) >> 4;
udelay(1);
data_out <<= 1;
}
/*
* Received 32-bit long value consist of:
* 31: EOC - (End Of Transmission) bit - should be 0
* 30: DMY - (Dummy) bit - should be 0
* 29: SIG - (Sign) bit - 1 if positive, 0 if negative
* 28: MSB - (Most Significant Bit) - the first bit of the
* conversion result
* ....
* 05: LSB - (Least Significant Bit)- the last bit of the
* conversion result
* 04-00: sub-LSB - sub-LSBs are basically noise, but when
* averaged properly, they can increase
* conversion precision up to 29 bits;
* they can be discarded without loss of
* resolution.
*/
if (data_in & MPC624_EOC_BIT)
dev_dbg(dev->class_dev, "EOC bit is set!");
if (data_in & MPC624_DMY_BIT)
dev_dbg(dev->class_dev, "DMY bit is set!");
if (data_in & MPC624_SGN_BIT) {
/*
* Voltage is positive
*
* comedi operates on unsigned numbers, so mask off EOC
* and DMY and don't clear the SGN bit
*/
data_in &= 0x3fffffff;
} else {
/*
* The voltage is negative
*
* data_in contains a number in 30-bit two's complement
* code and we must deal with it
*/
data_in |= MPC624_SGN_BIT;
data_in = ~data_in;
data_in += 1;
/* clear EOC and DMY bits */
data_in &= ~(MPC624_EOC_BIT | MPC624_DMY_BIT);
data_in = 0x20000000 - data_in;
}
return data_in;
}
static int mpc624_ai_eoc(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned long context)
{
unsigned char status;
status = inb(dev->iobase + MPC624_ADC);
if ((status & MPC624_ADBUSY) == 0)
return 0;
return -EBUSY;
}
static int mpc624_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
int ret;
int i;
/*
* WARNING:
* We always write 0 to GNSWA bit, so the channel range is +-/10.1Vdc
*/
outb(insn->chanspec, dev->iobase + MPC624_GNMUXCH);
for (i = 0; i < insn->n; i++) {
/* Trigger the conversion */
outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
udelay(1);
outb(MPC624_ADCS | MPC624_ADSCK, dev->iobase + MPC624_ADC);
udelay(1);
outb(0, dev->iobase + MPC624_ADC);
udelay(1);
/* Wait for the conversion to end */
ret = comedi_timeout(dev, s, insn, mpc624_ai_eoc, 0);
if (ret)
return ret;
data[i] = mpc624_ai_get_sample(dev, s);
}
return insn->n;
}
static int mpc624_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
struct mpc624_private *devpriv;
struct comedi_subdevice *s;
int ret;
ret = comedi_request_region(dev, it->options[0], 0x10);
if (ret)
return ret;
devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
if (!devpriv)
return -ENOMEM;
switch (it->options[1]) {
case 0:
devpriv->ai_speed = MPC624_SPEED_3_52_KHZ;
break;
case 1:
devpriv->ai_speed = MPC624_SPEED_1_76_KHZ;
break;
case 2:
devpriv->ai_speed = MPC624_SPEED_880_HZ;
break;
case 3:
devpriv->ai_speed = MPC624_SPEED_440_HZ;
break;
case 4:
devpriv->ai_speed = MPC624_SPEED_220_HZ;
break;
case 5:
devpriv->ai_speed = MPC624_SPEED_110_HZ;
break;
case 6:
devpriv->ai_speed = MPC624_SPEED_55_HZ;
break;
case 7:
devpriv->ai_speed = MPC624_SPEED_27_5_HZ;
break;
case 8:
devpriv->ai_speed = MPC624_SPEED_13_75_HZ;
break;
case 9:
devpriv->ai_speed = MPC624_SPEED_6_875_HZ;
break;
default:
devpriv->ai_speed = MPC624_SPEED_3_52_KHZ;
}
ret = comedi_alloc_subdevices(dev, 1);
if (ret)
return ret;
/* Analog Input subdevice */
s = &dev->subdevices[0];
s->type = COMEDI_SUBD_AI;
s->subdev_flags = SDF_READABLE | SDF_DIFF;
s->n_chan = 4;
s->maxdata = 0x3fffffff;
s->range_table = (it->options[1] == 0) ? &range_mpc624_bipolar1
: &range_mpc624_bipolar10;
s->insn_read = mpc624_ai_insn_read;
return 0;
}
static struct comedi_driver mpc624_driver = {
.driver_name = "mpc624",
.module = THIS_MODULE,
.attach = mpc624_attach,
.detach = comedi_legacy_detach,
};
module_comedi_driver(mpc624_driver);
MODULE_AUTHOR("Comedi https://www.comedi.org");
MODULE_DESCRIPTION("Comedi driver for Micro/sys MPC-624 PC/104 board");
MODULE_LICENSE("GPL");
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