Staging: comedi: add usb dt9812 driver (63274cd7) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/staging/comedi/drivers/Makefile

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	@@ -10,3 +10,4 @@ obj-$(CONFIG_COMEDI_PCI_DRIVERS) += mite.o
	# Comedi USB drivers		# Comedi USB drivers
	obj-$(CONFIG_COMEDI_USB_DRIVERS) += usbdux.o		obj-$(CONFIG_COMEDI_USB_DRIVERS) += usbdux.o
	obj-$(CONFIG_COMEDI_USB_DRIVERS) += usbduxfast.o		obj-$(CONFIG_COMEDI_USB_DRIVERS) += usbduxfast.o
			obj-$(CONFIG_COMEDI_USB_DRIVERS) += dt9812.o

drivers/staging/comedi/drivers/dt9812.c

0 → 100644

+957 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* comedi/drivers/dt9812.c
			* COMEDI driver for DataTranslation DT9812 USB module
			*
			* Copyright (C) 2005 Anders Blomdell <anders.blomdell@control.lth.se>
			*
			* COMEDI - Linux Control and Measurement Device Interface
			*
			* 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: dt9812
			Description: Data Translation DT9812 USB module
			Author: anders.blomdell@control.lth.se (Anders Blomdell)
			Status: in development
			Devices: [Data Translation] DT9812 (dt9812)
			Updated: Sun Nov 20 20:18:34 EST 2005

			This driver works, but bulk transfers not implemented. Might be a starting point
			for someone else. I found out too late that USB has too high latencies (>1 ms)
			for my needs.
			*/

			/*
			* Nota Bene:
			* 1. All writes to command pipe has to be 32 bytes (ISP1181B SHRTP=0 ?)
			* 2. The DDK source (as of sep 2005) is in error regarding the
			* input MUX bits (example code says P4, but firmware schematics
			* says P1).
			*/

			#include <linux/version.h>
			#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)

			#include <linux/kernel.h>
			#include <linux/errno.h>
			#include <linux/init.h>
			#include <linux/slab.h>
			#include <linux/module.h>
			#include <linux/kref.h>
			#include <asm/uaccess.h>
			#include <linux/usb.h>
			#include "../comedidev.h"
			#include "dt9812.h"

			#define DT9812_NUM_SLOTS 16

			static DECLARE_MUTEX(dt9812_mutex);

			static struct usb_device_id dt9812_table[] = {
			{USB_DEVICE(0x0867, 0x9812)},
			{} /* Terminating entry */
			};

			MODULE_DEVICE_TABLE(usb, dt9812_table);

			typedef struct usb_dt9812 {
			struct slot_dt9812 *slot;
			struct usb_device *udev;
			struct usb_interface *interface;
			u16 vendor;
			u16 product;
			u16 device;
			u32 serial;
			struct {
			__u8 addr;
			size_t size;
			} message_pipe, command_write, command_read, write_stream, read_stream;
			struct kref kref;
			u16 analog_out_shadow[2];
			u8 digital_out_shadow;
			} usb_dt9812_t;

			typedef struct comedi_dt9812 {
			struct slot_dt9812 *slot;
			u32 serial;
			} comedi_dt9812_t;

			typedef struct slot_dt9812 {
			struct semaphore mutex;
			u32 serial;
			usb_dt9812_t *usb;
			comedi_dt9812_t *comedi;
			} slot_dt9812_t;

			static const comedi_lrange dt9812_10_ain_range = { 1, {
			BIP_RANGE(10),
			}
			};

			static const comedi_lrange dt9812_2pt5_ain_range = { 1, {
			UNI_RANGE(2.5),
			}
			};

			static const comedi_lrange dt9812_10_aout_range = { 1, {
			BIP_RANGE(10),
			}
			};

			static const comedi_lrange dt9812_2pt5_aout_range = { 1, {
			UNI_RANGE(2.5),
			}
			};

			static slot_dt9812_t dt9812[DT9812_NUM_SLOTS];

			// Useful shorthand access to private data
			#define devpriv ((comedi_dt9812_t *)dev->private)

			static inline usb_dt9812_t to_dt9812_dev(struct kref d)
			{
			return container_of(d, usb_dt9812_t, kref);
			}

			static void dt9812_delete(struct kref *kref)
			{
			usb_dt9812_t *dev = to_dt9812_dev(kref);

			usb_put_dev(dev->udev);
			kfree(dev);
			}

			static int dt9812_read_info(usb_dt9812_t * dev,
			int offset, void *buf, size_t buf_size)
			{
			dt9812_usb_cmd_t cmd;
			int count, retval;

			cmd.cmd = cpu_to_le32(DT9812_R_FLASH_DATA);
			cmd.u.flash_data_info.address =
			cpu_to_le16(DT9812_DIAGS_BOARD_INFO_ADDR + offset);
			cmd.u.flash_data_info.numbytes = cpu_to_le16(buf_size);

			count = 32;
			retval = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->command_write.addr), &cmd, 32, // DT9812 only responds to 32 byte writes!!
			&count, HZ * 1);
			if (retval == 0) {
			retval = usb_bulk_msg(dev->udev,
			usb_rcvbulkpipe(dev->udev, dev->command_read.addr),
			buf, buf_size, &count, HZ * 1);
			}
			return retval;
			}

			static int dt9812_read_multiple_registers(usb_dt9812_t * dev,
			int reg_count, u8 * address, u8 * value)
			{
			dt9812_usb_cmd_t cmd;
			int i, count, retval;

			cmd.cmd = cpu_to_le32(DT9812_R_MULTI_BYTE_REG);
			cmd.u.read_multi_info.count = reg_count;
			for (i = 0; i < reg_count; i++) {
			cmd.u.read_multi_info.address[i] = address[i];
			}
			count = 32;
			retval = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->command_write.addr), &cmd, 32, // DT9812 only responds to 32 byte writes!!
			&count, HZ * 1);
			if (retval == 0) {
			retval = usb_bulk_msg(dev->udev,
			usb_rcvbulkpipe(dev->udev, dev->command_read.addr),
			value, reg_count, &count, HZ * 1);
			}
			return retval;
			}

			static int dt9812_write_multiple_registers(usb_dt9812_t * dev,
			int reg_count, u8 * address, u8 * value)
			{
			dt9812_usb_cmd_t cmd;
			int i, count, retval;

			cmd.cmd = cpu_to_le32(DT9812_W_MULTI_BYTE_REG);
			cmd.u.read_multi_info.count = reg_count;
			for (i = 0; i < reg_count; i++) {
			cmd.u.write_multi_info.write[i].address = address[i];
			cmd.u.write_multi_info.write[i].value = value[i];
			}
			retval = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->command_write.addr), &cmd, 32, // DT9812 only responds to 32 byte writes!!
			&count, HZ * 1);
			return retval;
			}

			static int dt9812_rmw_multiple_registers(usb_dt9812_t * dev,
			int reg_count, dt9812_rmw_byte_t rmw[])
			{
			dt9812_usb_cmd_t cmd;
			int i, count, retval;

			cmd.cmd = cpu_to_le32(DT9812_RMW_MULTI_BYTE_REG);
			cmd.u.rmw_multi_info.count = reg_count;
			for (i = 0; i < reg_count; i++) {
			cmd.u.rmw_multi_info.rmw[i] = rmw[i];
			}
			retval = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->command_write.addr), &cmd, 32, // DT9812 only responds to 32 byte writes!!
			&count, HZ * 1);
			return retval;
			}

			static int dt9812_digital_in(slot_dt9812_t * slot, u8 * bits)
			{
			int result = -ENODEV;

			down(&slot->mutex);
			if (slot->usb) {
			u8 reg[2] = { F020_SFR_P3, F020_SFR_P1 };
			u8 value[2];

			result = dt9812_read_multiple_registers(slot->usb, 2, reg,
			value);
			if (result == 0) {
			// bits 0-6 in F020_SFR_P3 are bits 0-6 in the digital input port
			// bit 3 in F020_SFR_P1 is bit 7 in the digital input port
			*bits = (value[0] & 0x7f) \| ((value[1] & 0x08) << 4);
			// printk("%2.2x, %2.2x -> %2.2x\n", value[0], value[1], *bits);
			}
			}
			up(&slot->mutex);

			return result;
			}

			static int dt9812_digital_out(slot_dt9812_t * slot, u8 bits)
			{
			int result = -ENODEV;

			down(&slot->mutex);
			if (slot->usb) {
			u8 reg[1];
			u8 value[1];

			reg[0] = F020_SFR_P2;
			value[0] = bits;
			result = dt9812_write_multiple_registers(slot->usb, 1, reg,
			value);
			slot->usb->digital_out_shadow = bits;
			}
			up(&slot->mutex);
			return result;
			}

			static int dt9812_digital_out_shadow(slot_dt9812_t * slot, u8 * bits)
			{
			int result = -ENODEV;

			down(&slot->mutex);
			if (slot->usb) {
			*bits = slot->usb->digital_out_shadow;
			result = 0;
			}
			up(&slot->mutex);
			return result;
			}

			static void dt9812_configure_mux(usb_dt9812_t * dev,
			dt9812_rmw_byte_t * rmw, int channel)
			{
			if (dev->device == DT9812_DEVID_DT9812_10) {
			// In the DT9812/10V MUX is selected by P1.5-7
			rmw->address = F020_SFR_P1;
			rmw->and_mask = 0xe0;
			rmw->or_value = channel << 5;
			} else {
			// In the DT9812/2.5V, the internal mux is selected by bits 0:2
			rmw->address = F020_SFR_AMX0SL;
			rmw->and_mask = 0xff;
			rmw->or_value = channel & 0x07;
			}
			}

			static void dt9812_configure_gain(usb_dt9812_t * dev,
			dt9812_rmw_byte_t * rmw, dt9812_gain_t gain)
			{
			if (dev->device == DT9812_DEVID_DT9812_10) {
			// In the DT9812/10V, there is an external gain of 0.5
			gain <<= 1;
			}

			rmw->address = F020_SFR_ADC0CF;
			rmw->and_mask =
			F020_MASK_ADC0CF_AMP0GN2 \|
			F020_MASK_ADC0CF_AMP0GN1 \| F020_MASK_ADC0CF_AMP0GN0;
			switch (gain) {
			// 000 -> Gain = 1
			// 001 -> Gain = 2
			// 010 -> Gain = 4
			// 011 -> Gain = 8
			// 10x -> Gain = 16
			// 11x -> Gain = 0.5
			case DT9812_GAIN_0PT5:{
			rmw->or_value = F020_MASK_ADC0CF_AMP0GN2
			\|\| F020_MASK_ADC0CF_AMP0GN1;
			}
			break;
			case DT9812_GAIN_1:{
			rmw->or_value = 0x00;
			}
			break;
			case DT9812_GAIN_2:{
			rmw->or_value = F020_MASK_ADC0CF_AMP0GN0;
			}
			break;
			case DT9812_GAIN_4:{
			rmw->or_value = F020_MASK_ADC0CF_AMP0GN1;
			}
			break;
			case DT9812_GAIN_8:{
			rmw->or_value = F020_MASK_ADC0CF_AMP0GN1
			\|\| F020_MASK_ADC0CF_AMP0GN0;
			}
			break;
			case DT9812_GAIN_16:{
			rmw->or_value = F020_MASK_ADC0CF_AMP0GN2;
			}
			break;
			default:{
			err("Illegal gain %d\n", gain);
			}
			}
			}

			static int dt9812_analog_in(slot_dt9812_t * slot,
			int channel, u16 * value, dt9812_gain_t gain)
			{
			int result = -ENODEV;

			down(&slot->mutex);
			if (slot->usb) {
			dt9812_rmw_byte_t rmw[3];

			// 1 select the gain
			dt9812_configure_gain(slot->usb, &rmw[0], gain);

			// 2 set the MUX to select the channel
			dt9812_configure_mux(slot->usb, &rmw[1], channel);

			// 3 start conversion
			rmw[2].address = F020_SFR_ADC0CN;
			rmw[2].and_mask = 0xff;
			rmw[2].or_value =
			F020_MASK_ADC0CN_AD0EN \| F020_MASK_ADC0CN_AD0BUSY;

			result = dt9812_rmw_multiple_registers(slot->usb, 3, rmw);
			if (result == 0) {
			// read the status and ADC
			u8 reg[3] = { F020_SFR_ADC0CN, F020_SFR_ADC0H,
			F020_SFR_ADC0L
			};
			u8 val[3];
			result = dt9812_read_multiple_registers(slot->usb, 3,
			reg, val);
			if (result == 0) {
			// An ADC conversion takes 16 SAR clocks cycles, i.e. about 9us.
			// Therefore, between the instant that AD0BUSY was set via
			// dt9812_rmw_multiple_registers and the read of AD0BUSY via
			// dt9812_read_multiple_registers, the conversion
			// should be complete since these two operations require two USB
			// transactions each taking at least a millisecond to complete.
			// However, lets make sure that conversion is finished.
			if ((val[0] & (F020_MASK_ADC0CN_AD0INT \|
			F020_MASK_ADC0CN_AD0BUSY))
			== F020_MASK_ADC0CN_AD0INT) {
			switch (slot->usb->device) {
			case DT9812_DEVID_DT9812_10:{
			// For DT9812-10V the personality module set the encoding to 2's
			// complement. Hence, convert it before returning it
			*value = ((val[1] << 8)
			\| val[2]) +
			0x800;
			}
			break;
			case DT9812_DEVID_DT9812_2PT5:{
			*value = (val[1] << 8) \|
			val[2];
			}
			break;
			}
			}
			}
			}
			}
			up(&slot->mutex);
			return result;
			}

			static int dt9812_analog_out_shadow(slot_dt9812_t * slot, int channel,
			u16 * value)
			{
			int result = -ENODEV;

			down(&slot->mutex);
			if (slot->usb) {
			*value = slot->usb->analog_out_shadow[channel];
			result = 0;
			}
			up(&slot->mutex);

			return result;
			}

			static int dt9812_analog_out(slot_dt9812_t * slot, int channel, u16 value)
			{
			int result = -ENODEV;

			down(&slot->mutex);
			if (slot->usb) {
			dt9812_rmw_byte_t rmw[3];

			switch (channel) {
			case 0:{
			// 1. Set DAC mode
			rmw[0].address = F020_SFR_DAC0CN;
			rmw[0].and_mask = 0xff;
			rmw[0].or_value = F020_MASK_DACxCN_DACxEN;

			// 2 load low byte of DAC value first
			rmw[1].address = F020_SFR_DAC0L;
			rmw[1].and_mask = 0xff;
			rmw[1].or_value = value & 0xff;

			// 3 load high byte of DAC value next to latch the 12-bit value
			rmw[2].address = F020_SFR_DAC0H;
			rmw[2].and_mask = 0xff;
			rmw[2].or_value = (value >> 8) & 0xf;
			}
			break;
			case 1:{
			// 1. Set DAC mode
			rmw[0].address = F020_SFR_DAC1CN;
			rmw[0].and_mask = 0xff;
			rmw[0].or_value = F020_MASK_DACxCN_DACxEN;

			// 2 load low byte of DAC value first
			rmw[1].address = F020_SFR_DAC1L;
			rmw[1].and_mask = 0xff;
			rmw[1].or_value = value & 0xff;

			// 3 load high byte of DAC value next to latch the 12-bit value
			rmw[2].address = F020_SFR_DAC1H;
			rmw[2].and_mask = 0xff;
			rmw[2].or_value = (value >> 8) & 0xf;
			}
			break;
			}
			result = dt9812_rmw_multiple_registers(slot->usb, 3, rmw);
			slot->usb->analog_out_shadow[channel] = value;
			}
			up(&slot->mutex);

			return result;
			}

			/*
			* USB framework functions
			*/

			static int dt9812_probe(struct usb_interface *interface,
			const struct usb_device_id *id)
			{
			int retval = -ENOMEM;
			usb_dt9812_t *dev = NULL;
			struct usb_host_interface *iface_desc;
			struct usb_endpoint_descriptor *endpoint;
			int i;
			u8 fw;

			// allocate memory for our device state and initialize it
			dev = kzalloc(sizeof(*dev), GFP_KERNEL);
			if (dev == NULL) {
			err("Out of memory");
			goto error;
			}
			kref_init(&dev->kref);

			dev->udev = usb_get_dev(interface_to_usbdev(interface));
			dev->interface = interface;

			// Check endpoints
			iface_desc = interface->cur_altsetting;

			if (iface_desc->desc.bNumEndpoints != 5) {
			err("Wrong number of endpints.");
			retval = -ENODEV;
			goto error;
			}

			for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
			int direction = -1;
			endpoint = &iface_desc->endpoint[i].desc;
			switch (i) {
			case 0:{
			direction = USB_DIR_IN;
			dev->message_pipe.addr =
			endpoint->bEndpointAddress;
			dev->message_pipe.size =
			le16_to_cpu(endpoint->wMaxPacketSize);
			}
			break;
			case 1:{
			direction = USB_DIR_OUT;
			dev->command_write.addr =
			endpoint->bEndpointAddress;
			dev->command_write.size =
			le16_to_cpu(endpoint->wMaxPacketSize);
			}
			break;
			case 2:{
			direction = USB_DIR_IN;
			dev->command_read.addr =
			endpoint->bEndpointAddress;
			dev->command_read.size =
			le16_to_cpu(endpoint->wMaxPacketSize);
			}
			break;
			case 3:{
			direction = USB_DIR_OUT;
			dev->write_stream.addr =
			endpoint->bEndpointAddress;
			dev->write_stream.size =
			le16_to_cpu(endpoint->wMaxPacketSize);
			}
			break;
			case 4:{
			direction = USB_DIR_IN;
			dev->read_stream.addr =
			endpoint->bEndpointAddress;
			dev->read_stream.size =
			le16_to_cpu(endpoint->wMaxPacketSize);
			}
			break;
			}
			if ((endpoint->bEndpointAddress & USB_DIR_IN) != direction) {
			err("Endpoint has wrong direction.");
			retval = -ENODEV;
			goto error;
			}
			}
			if (dt9812_read_info(dev, 0, &fw, sizeof(fw)) != 0) {
			// Seems like a configuration reset is necessary if driver
			// is reloaded while device is attached
			int i;

			usb_reset_configuration(dev->udev);
			for (i = 0; i < 10; i++) {
			retval = dt9812_read_info(dev, 1, &fw, sizeof(fw));
			if (retval == 0) {
			printk("usb_reset_configuration succeded after %d iterations\n", i);
			break;
			}
			}
			}

			if (dt9812_read_info(dev, 1, &dev->vendor, sizeof(dev->vendor)) != 0) {
			err("Failed to read vendor.");
			retval = -ENODEV;
			goto error;
			}
			if (dt9812_read_info(dev, 3, &dev->product, sizeof(dev->product)) != 0) {
			err("Failed to read product.");
			retval = -ENODEV;
			goto error;
			}
			if (dt9812_read_info(dev, 5, &dev->device, sizeof(dev->device)) != 0) {
			err("Failed to read device.");
			retval = -ENODEV;
			goto error;
			}
			if (dt9812_read_info(dev, 7, &dev->serial, sizeof(dev->serial)) != 0) {
			err("Failed to read serial.");
			retval = -ENODEV;
			goto error;
			}

			dev->vendor = le16_to_cpu(dev->vendor);
			dev->product = le16_to_cpu(dev->product);
			dev->device = le16_to_cpu(dev->device);
			dev->serial = le32_to_cpu(dev->serial);
			switch (dev->device) {
			case DT9812_DEVID_DT9812_10:{
			dev->analog_out_shadow[0] = 0x0800;
			dev->analog_out_shadow[1] = 0x800;
			}
			break;
			case DT9812_DEVID_DT9812_2PT5:{
			dev->analog_out_shadow[0] = 0x0000;
			dev->analog_out_shadow[1] = 0x0000;
			}
			break;
			}
			dev->digital_out_shadow = 0;

			// save our data pointer in this interface device a
			usb_set_intfdata(interface, dev);

			// let the user know what node this device is now attached to
			dev_info(&interface->dev, "USB DT9812 (%4.4x.%4.4x.%4.4x) #0x%8.8x\n",
			dev->vendor, dev->product, dev->device, dev->serial);

			down(&dt9812_mutex);
			{
			// Find a slot for the USB device
			slot_dt9812_t *first = NULL;
			slot_dt9812_t *best = NULL;

			for (i = 0; i < DT9812_NUM_SLOTS; i++) {
			if (!first && !dt9812[i].usb && dt9812[i].serial == 0) {
			first = &dt9812[i];
			}
			if (!best && dt9812[i].serial == dev->serial) {
			best = &dt9812[i];
			}
			}

			if (!best) {
			best = first;
			}

			if (best) {
			down(&best->mutex);
			best->usb = dev;
			dev->slot = best;
			up(&best->mutex);
			}
			}
			up(&dt9812_mutex);

			return 0;

			error:
			if (dev) {
			kref_put(&dev->kref, dt9812_delete);
			}
			return retval;
			}

			static void dt9812_disconnect(struct usb_interface *interface)
			{
			usb_dt9812_t *dev;
			int minor = interface->minor;

			down(&dt9812_mutex);
			dev = usb_get_intfdata(interface);
			if (dev->slot) {
			down(&dev->slot->mutex);
			dev->slot->usb = NULL;
			up(&dev->slot->mutex);
			dev->slot = NULL;
			}
			usb_set_intfdata(interface, NULL);
			up(&dt9812_mutex);

			/* queue final destruction */
			kref_put(&dev->kref, dt9812_delete);

			dev_info(&interface->dev, "USB Dt9812 #%d now disconnected\n", minor);
			}

			static struct usb_driver dt9812_usb_driver = {
			#ifdef COMEDI_HAVE_USB_DRIVER_OWNER
			.owner = THIS_MODULE,
			#endif
			.name = "dt9812",
			.probe = dt9812_probe,
			.disconnect = dt9812_disconnect,
			.id_table = dt9812_table,
			};

			/*
			* Comedi functions
			*/

			static void dt9812_comedi_open(comedi_device * dev)
			{
			down(&devpriv->slot->mutex);
			if (devpriv->slot->usb) {
			// We have an attached device, fill in current range info
			comedi_subdevice *s;

			s = &dev->subdevices[0];
			s->n_chan = 8;
			s->maxdata = 1;

			s = &dev->subdevices[1];
			s->n_chan = 8;
			s->maxdata = 1;

			s = &dev->subdevices[2];
			s->n_chan = 8;
			switch (devpriv->slot->usb->device) {
			case 0:{
			s->maxdata = 4095;
			s->range_table = &dt9812_10_ain_range;
			}
			break;
			case 1:{
			s->maxdata = 4095;
			s->range_table = &dt9812_2pt5_ain_range;
			}
			break;
			}

			s = &dev->subdevices[3];
			s->n_chan = 2;
			switch (devpriv->slot->usb->device) {
			case 0:{
			s->maxdata = 4095;
			s->range_table = &dt9812_10_aout_range;
			}
			break;
			case 1:{
			s->maxdata = 4095;
			s->range_table = &dt9812_2pt5_aout_range;
			}
			break;
			}
			}
			up(&devpriv->slot->mutex);
			}

			static int dt9812_di_rinsn(comedi_device * dev, comedi_subdevice * s,
			comedi_insn * insn, lsampl_t * data)
			{
			int n;
			u8 bits = 0;

			dt9812_digital_in(devpriv->slot, &bits);
			for (n = 0; n < insn->n; n++) {
			data[n] = ((1 << insn->chanspec) & bits) != 0;
			}
			return n;
			}

			static int dt9812_do_winsn(comedi_device * dev, comedi_subdevice * s,
			comedi_insn * insn, lsampl_t * data)
			{
			int n;
			u8 bits = 0;

			dt9812_digital_out_shadow(devpriv->slot, &bits);
			for (n = 0; n < insn->n; n++) {
			u8 mask = 1 << insn->chanspec;

			bits &= ~mask;
			if (data[n]) {
			bits \|= mask;
			}
			}
			dt9812_digital_out(devpriv->slot, bits);
			return n;
			}

			static int dt9812_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
			comedi_insn * insn, lsampl_t * data)
			{
			int n;

			for (n = 0; n < insn->n; n++) {
			u16 value = 0;

			dt9812_analog_in(devpriv->slot, insn->chanspec, &value,
			DT9812_GAIN_1);
			data[n] = value;
			}
			return n;
			}

			static int dt9812_ao_rinsn(comedi_device * dev, comedi_subdevice * s,
			comedi_insn * insn, lsampl_t * data)
			{
			int n;

			for (n = 0; n < insn->n; n++) {
			u16 value = 0;

			dt9812_analog_out_shadow(devpriv->slot, insn->chanspec, &value);
			data[n] = value;
			}
			return n;
			}

			static int dt9812_ao_winsn(comedi_device * dev, comedi_subdevice * s,
			comedi_insn * insn, lsampl_t * data)
			{
			int n;

			for (n = 0; n < insn->n; n++) {
			dt9812_analog_out(devpriv->slot, insn->chanspec, data[n]);
			}
			return n;
			}

			static int dt9812_attach(comedi_device * dev, comedi_devconfig * it)
			{
			int i;
			comedi_subdevice *s;

			dev->board_name = "dt9812";

			if (alloc_private(dev, sizeof(comedi_dt9812_t)) < 0) {
			return -ENOMEM;
			}
			// Special open routine, since USB unit may be unattached at
			// comedi_config time, hence range can not be determined
			dev->open = dt9812_comedi_open;

			devpriv->serial = it->options[0];

			// Allocate subdevices
			if (alloc_subdevices(dev, 4) < 0) {
			return -ENOMEM;
			}

			/* digital input subdevice */
			s = dev->subdevices + 0;
			s->type = COMEDI_SUBD_DI;
			s->subdev_flags = SDF_READABLE;
			s->n_chan = 0;
			s->maxdata = 1;
			s->range_table = &range_digital;
			s->insn_read = &dt9812_di_rinsn;

			/* digital output subdevice */
			s = dev->subdevices + 1;
			s->type = COMEDI_SUBD_DO;
			s->subdev_flags = SDF_WRITEABLE;
			s->n_chan = 0;
			s->maxdata = 1;
			s->range_table = &range_digital;
			s->insn_write = &dt9812_do_winsn;

			/* analog input subdevice */
			s = dev->subdevices + 2;
			s->type = COMEDI_SUBD_AI;
			s->subdev_flags = SDF_READABLE \| SDF_GROUND;
			s->n_chan = 0;
			s->maxdata = 1;
			s->range_table = 0;
			s->insn_read = &dt9812_ai_rinsn;

			/* analog output subdevice */
			s = dev->subdevices + 3;
			s->type = COMEDI_SUBD_AO;
			s->subdev_flags = SDF_WRITEABLE;
			s->n_chan = 0;
			s->maxdata = 1;
			s->range_table = 0;
			s->insn_write = &dt9812_ao_winsn;
			s->insn_read = &dt9812_ao_rinsn;

			printk("comedi%d: successfully attached to dt9812.\n", dev->minor);

			down(&dt9812_mutex);
			// Find a slot for the comedi device
			{
			slot_dt9812_t *first = NULL;
			slot_dt9812_t *best = NULL;
			for (i = 0; i < DT9812_NUM_SLOTS; i++) {
			if (!first && !dt9812[i].comedi) {
			// First free slot from comedi side
			first = &dt9812[i];
			}
			if (!best &&
			dt9812[i].usb
			&& dt9812[i].usb->serial == devpriv->serial) {
			// We have an attaced device with matching ID
			best = &dt9812[i];
			}
			}
			if (!best) {
			best = first;
			}
			if (best) {
			down(&best->mutex);
			best->comedi = devpriv;
			best->serial = devpriv->serial;
			devpriv->slot = best;
			up(&best->mutex);
			}
			}
			up(&dt9812_mutex);

			return 0;
			}

			static int dt9812_detach(comedi_device * dev)
			{

			return 0;
			}

			static comedi_driver dt9812_comedi_driver = {
			.module = THIS_MODULE,
			.driver_name = "dt9812",
			.attach = dt9812_attach,
			.detach = dt9812_detach,
			};

			static int __init usb_dt9812_init(void)
			{
			int result, i;

			// Initialize all driver slots
			for (i = 0; i < DT9812_NUM_SLOTS; i++) {
			init_MUTEX(&dt9812[i].mutex);
			dt9812[i].serial = 0;
			dt9812[i].usb = NULL;
			dt9812[i].comedi = NULL;
			}
			dt9812[12].serial = 0x0;

			// register with the USB subsystem
			result = usb_register(&dt9812_usb_driver);
			if (result) {
			err("usb_register failed. Error number %d", result);
			}
			// register with comedi
			result = comedi_driver_register(&dt9812_comedi_driver);
			if (result) {
			usb_deregister(&dt9812_usb_driver);
			err("comedi_driver_register failed. Error number %d", result);
			}

			return result;
			}

			static void __exit usb_dt9812_exit(void)
			{
			// unregister with comedi
			comedi_driver_unregister(&dt9812_comedi_driver);

			/* deregister this driver with the USB subsystem */
			usb_deregister(&dt9812_usb_driver);
			}

			module_init(usb_dt9812_init);
			module_exit(usb_dt9812_exit);

			MODULE_AUTHOR("Anders Blomdell <anders.blomdell@control.lth.se>");
			MODULE_DESCRIPTION("Comedi DT9812 driver");
			MODULE_LICENSE("GPL");

			#endif // LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)