// 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 */ /* * Driver: mpc624 * Description: Micro/sys MPC-624 PC/104 board * Devices: [Micro/sys] MPC-624 (mpc624) * Author: Stanislaw Raczynski * 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 #include "../comedidev.h" #include /* 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");