1 files changed, 391 insertions, 640 deletions

diff --git a/drivers/staging/comedi/drivers/dt9812.c b/drivers/staging/comedi/drivers/dt9812.c
index 81eb5ed6ec97..6c60949d9193 100644
--- a/drivers/staging/comedi/drivers/dt9812.c
+++ b/drivers/staging/comedi/drivers/dt9812.c
@@ -15,11 +15,6 @@
  * 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.
- *
  */
 
 /*
@@ -43,14 +38,11 @@ for my needs.
  *      says P1).
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
 #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 <linux/uaccess.h>
 #include <linux/usb.h>
 
@@ -60,6 +52,9 @@ for my needs.
 #define DT9812_MAX_WRITE_CMD_PIPE_SIZE	32
 #define DT9812_MAX_READ_CMD_PIPE_SIZE	32
 
+/* usb_bulk_msg() timout in milliseconds */
+#define DT9812_USB_TIMEOUT		1000
+
 /*
  * See Silican Laboratories C8051F020/1/2/3 manual
  */
@@ -242,87 +237,25 @@ struct dt9812_usb_cmd {
 		struct dt9812_write_multi write_multi_info;
 		struct dt9812_rmw_multi rmw_multi_info;
 	} u;
-#if 0
-	WRITE_BYTE_INFO WriteByteInfo;
-	READ_BYTE_INFO ReadByteInfo;
-	WRITE_MULTI_INFO WriteMultiInfo;
-	READ_MULTI_INFO ReadMultiInfo;
-	RMW_BYTE_INFO RMWByteInfo;
-	RMW_MULTI_INFO RMWMultiInfo;
-	DAC_THRESHOLD_INFO DacThresholdInfo;
-	INT_ON_CHANGE_MASK_INFO IntOnChangeMaskInfo;
-	CGL_INFO CglInfo;
-	SUBSYSTEM_INFO SubsystemInfo;
-	CAL_POT_CMD CalPotCmd;
-	WRITE_DEV_BYTE_INFO WriteDevByteInfo;
-	READ_DEV_BYTE_INFO ReadDevByteInfo;
-	WRITE_DEV_MULTI_INFO WriteDevMultiInfo;
-	READ_DEV_MULTI_INFO ReadDevMultiInfo;
-	READ_SINGLE_VALUE_INFO ReadSingleValueInfo;
-	WRITE_SINGLE_VALUE_INFO WriteSingleValueInfo;
-#endif
 };
 
-#define DT9812_NUM_SLOTS	16
-
-static DEFINE_SEMAPHORE(dt9812_mutex);
-
-static const struct usb_device_id dt9812_table[] = {
-	{USB_DEVICE(0x0867, 0x9812)},
-	{}			/* Terminating entry */
-};
-
-MODULE_DEVICE_TABLE(usb, dt9812_table);
-
-struct usb_dt9812 {
-	struct slot_dt9812 *slot;
-	struct usb_device *udev;
-	struct usb_interface *interface;
-	u16 vendor;
-	u16 product;
-	u16 device;
-	u32 serial;
+struct dt9812_private {
+	struct semaphore sem;
 	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;
-};
-
-struct comedi_dt9812 {
-	struct slot_dt9812 *slot;
-	u32 serial;
-};
-
-struct slot_dt9812 {
-	struct semaphore mutex;
-	u32 serial;
-	struct usb_dt9812 *usb;
-	struct comedi_dt9812 *comedi;
+	} cmd_wr, cmd_rd;
+	u16 device;
+	u16 ao_shadow[2];
 };
 
-static struct slot_dt9812 dt9812[DT9812_NUM_SLOTS];
-
-static inline struct usb_dt9812 *to_dt9812_dev(struct kref *d)
-{
-	return container_of(d, struct usb_dt9812, kref);
-}
-
-static void dt9812_delete(struct kref *kref)
-{
-	struct usb_dt9812 *dev = to_dt9812_dev(kref);
-
-	usb_put_dev(dev->udev);
-	kfree(dev);
-}
-
-static int dt9812_read_info(struct usb_dt9812 *dev, int offset, void *buf,
-			    size_t buf_size)
+static int dt9812_read_info(struct comedi_device *dev,
+			    int offset, void *buf, size_t buf_size)
 {
+	struct usb_device *usb = comedi_to_usb_dev(dev);
+	struct dt9812_private *devpriv = dev->private;
 	struct dt9812_usb_cmd cmd;
-	int count, retval;
+	int count, ret;
 
 	cmd.cmd = cpu_to_le32(DT9812_R_FLASH_DATA);
 	cmd.u.flash_data_info.address =
@@ -330,25 +263,23 @@ static int dt9812_read_info(struct usb_dt9812 *dev, int offset, void *buf,
 	cmd.u.flash_data_info.numbytes = cpu_to_le16(buf_size);
 
 	/* DT9812 only responds to 32 byte writes!! */
-	count = 32;
-	retval = usb_bulk_msg(dev->udev,
-			      usb_sndbulkpipe(dev->udev,
-					      dev->command_write.addr),
-			      &cmd, 32, &count, HZ * 1);
-	if (retval)
-		return retval;
-	retval = usb_bulk_msg(dev->udev,
-			      usb_rcvbulkpipe(dev->udev,
-					      dev->command_read.addr),
-			      buf, buf_size, &count, HZ * 1);
-	return retval;
+	ret = usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr),
+			   &cmd, 32, &count, DT9812_USB_TIMEOUT);
+	if (ret)
+		return ret;
+
+	return usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr),
+			    buf, buf_size, &count, DT9812_USB_TIMEOUT);
 }
 
-static int dt9812_read_multiple_registers(struct usb_dt9812 *dev, int reg_count,
-					  u8 *address, u8 *value)
+static int dt9812_read_multiple_registers(struct comedi_device *dev,
+					  int reg_count, u8 *address,
+					  u8 *value)
 {
+	struct usb_device *usb = comedi_to_usb_dev(dev);
+	struct dt9812_private *devpriv = dev->private;
 	struct dt9812_usb_cmd cmd;
-	int i, count, retval;
+	int i, count, ret;
 
 	cmd.cmd = cpu_to_le32(DT9812_R_MULTI_BYTE_REG);
 	cmd.u.read_multi_info.count = reg_count;
@@ -356,26 +287,23 @@ static int dt9812_read_multiple_registers(struct usb_dt9812 *dev, int reg_count,
 		cmd.u.read_multi_info.address[i] = address[i];
 
 	/* DT9812 only responds to 32 byte writes!! */
-	count = 32;
-	retval = usb_bulk_msg(dev->udev,
-			      usb_sndbulkpipe(dev->udev,
-					      dev->command_write.addr),
-			      &cmd, 32, &count, HZ * 1);
-	if (retval)
-		return retval;
-	retval = usb_bulk_msg(dev->udev,
-			      usb_rcvbulkpipe(dev->udev,
-					      dev->command_read.addr),
-			      value, reg_count, &count, HZ * 1);
-	return retval;
+	ret = usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr),
+			   &cmd, 32, &count, DT9812_USB_TIMEOUT);
+	if (ret)
+		return ret;
+
+	return usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr),
+			    value, reg_count, &count, DT9812_USB_TIMEOUT);
 }
 
-static int dt9812_write_multiple_registers(struct usb_dt9812 *dev,
+static int dt9812_write_multiple_registers(struct comedi_device *dev,
 					   int reg_count, u8 *address,
 					   u8 *value)
 {
+	struct usb_device *usb = comedi_to_usb_dev(dev);
+	struct dt9812_private *devpriv = dev->private;
 	struct dt9812_usb_cmd cmd;
-	int i, count, retval;
+	int i, count;
 
 	cmd.cmd = cpu_to_le32(DT9812_W_MULTI_BYTE_REG);
 	cmd.u.read_multi_info.count = reg_count;
@@ -383,19 +311,20 @@ static int dt9812_write_multiple_registers(struct usb_dt9812 *dev,
 		cmd.u.write_multi_info.write[i].address = address[i];
 		cmd.u.write_multi_info.write[i].value = value[i];
 	}
+
 	/* DT9812 only responds to 32 byte writes!! */
-	retval = usb_bulk_msg(dev->udev,
-			      usb_sndbulkpipe(dev->udev,
-					      dev->command_write.addr),
-			      &cmd, 32, &count, HZ * 1);
-	return retval;
+	return usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr),
+			    &cmd, 32, &count, DT9812_USB_TIMEOUT);
 }
 
-static int dt9812_rmw_multiple_registers(struct usb_dt9812 *dev, int reg_count,
+static int dt9812_rmw_multiple_registers(struct comedi_device *dev,
+					 int reg_count,
 					 struct dt9812_rmw_byte *rmw)
 {
+	struct usb_device *usb = comedi_to_usb_dev(dev);
+	struct dt9812_private *devpriv = dev->private;
 	struct dt9812_usb_cmd cmd;
-	int i, count, retval;
+	int i, count;
 
 	cmd.cmd = cpu_to_le32(DT9812_RMW_MULTI_BYTE_REG);
 	cmd.u.rmw_multi_info.count = reg_count;
@@ -403,76 +332,52 @@ static int dt9812_rmw_multiple_registers(struct usb_dt9812 *dev, int reg_count,
 		cmd.u.rmw_multi_info.rmw[i] = rmw[i];
 
 	/* DT9812 only responds to 32 byte writes!! */
-	retval = usb_bulk_msg(dev->udev,
-			      usb_sndbulkpipe(dev->udev,
-					      dev->command_write.addr),
-			      &cmd, 32, &count, HZ * 1);
-	return retval;
+	return usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr),
+			    &cmd, 32, &count, DT9812_USB_TIMEOUT);
 }
 
-static int dt9812_digital_in(struct slot_dt9812 *slot, u8 *bits)
+static int dt9812_digital_in(struct comedi_device *dev, u8 *bits)
 {
-	int result = -ENODEV;
-
-	down(&slot->mutex);
-	if (slot->usb) {
-		u8 reg[2] = { F020_SFR_P3, F020_SFR_P1 };
-		u8 value[2];
+	struct dt9812_private *devpriv = dev->private;
+	u8 reg[2] = { F020_SFR_P3, F020_SFR_P1 };
+	u8 value[2];
+	int ret;
 
-		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); */
-		}
+	down(&devpriv->sem);
+	ret = dt9812_read_multiple_registers(dev, 2, reg, value);
+	if (ret == 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);
 	}
-	up(&slot->mutex);
+	up(&devpriv->sem);
 
-	return result;
+	return ret;
 }
 
-static int dt9812_digital_out(struct slot_dt9812 *slot, u8 bits)
+static int dt9812_digital_out(struct comedi_device *dev, 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;
-}
+	struct dt9812_private *devpriv = dev->private;
+	u8 reg[1] = { F020_SFR_P2 };
+	u8 value[1] = { bits };
+	int ret;
 
-static int dt9812_digital_out_shadow(struct slot_dt9812 *slot, u8 *bits)
-{
-	int result = -ENODEV;
+	down(&devpriv->sem);
+	ret = dt9812_write_multiple_registers(dev, 1, reg, value);
+	up(&devpriv->sem);
 
-	down(&slot->mutex);
-	if (slot->usb) {
-		*bits = slot->usb->digital_out_shadow;
-		result = 0;
-	}
-	up(&slot->mutex);
-	return result;
+	return ret;
 }
 
-static void dt9812_configure_mux(struct usb_dt9812 *dev,
+static void dt9812_configure_mux(struct comedi_device *dev,
 				 struct dt9812_rmw_byte *rmw, int channel)
 {
-	if (dev->device == DT9812_DEVID_DT9812_10) {
+	struct dt9812_private *devpriv = dev->private;
+
+	if (devpriv->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;
@@ -485,18 +390,21 @@ static void dt9812_configure_mux(struct usb_dt9812 *dev,
 	}
 }
 
-static void dt9812_configure_gain(struct usb_dt9812 *dev,
+static void dt9812_configure_gain(struct comedi_device *dev,
 				  struct dt9812_rmw_byte *rmw,
 				  enum dt9812_gain gain)
 {
-	if (dev->device == DT9812_DEVID_DT9812_10) {
-		/* In the DT9812/10V, there is an external gain of 0.5 */
+	struct dt9812_private *devpriv = dev->private;
+
+	/* In the DT9812/10V, there is an external gain of 0.5 */
+	if (devpriv->device == DT9812_DEVID_DT9812_10)
 		gain <<= 1;
-	}
 
 	rmw->address = F020_SFR_ADC0CF;
 	rmw->and_mask = F020_MASK_ADC0CF_AMP0GN2 |
-	    F020_MASK_ADC0CF_AMP0GN1 | F020_MASK_ADC0CF_AMP0GN0;
+			F020_MASK_ADC0CF_AMP0GN1 |
+			F020_MASK_ADC0CF_AMP0GN0;
+
 	switch (gain) {
 		/*
 		 * 000 -> Gain =  1
@@ -508,8 +416,10 @@ static void dt9812_configure_gain(struct usb_dt9812 *dev,
 		 */
 	case DT9812_GAIN_0PT5:
 		rmw->or_value = F020_MASK_ADC0CF_AMP0GN2 |
-		    F020_MASK_ADC0CF_AMP0GN1;
+				F020_MASK_ADC0CF_AMP0GN1;
 		break;
+	default:
+		/* this should never happen, just use a gain of 1 */
 	case DT9812_GAIN_1:
 		rmw->or_value = 0x00;
 		break;
@@ -521,20 +431,18 @@ static void dt9812_configure_gain(struct usb_dt9812 *dev,
 		break;
 	case DT9812_GAIN_8:
 		rmw->or_value = F020_MASK_ADC0CF_AMP0GN1 |
-		    F020_MASK_ADC0CF_AMP0GN0;
+				F020_MASK_ADC0CF_AMP0GN0;
 		break;
 	case DT9812_GAIN_16:
 		rmw->or_value = F020_MASK_ADC0CF_AMP0GN2;
 		break;
-	default:
-		dev_err(&dev->interface->dev, "Illegal gain %d\n", gain);
-
 	}
 }
 
-static int dt9812_analog_in(struct slot_dt9812 *slot, int channel, u16 *value,
-			    enum dt9812_gain gain)
+static int dt9812_analog_in(struct comedi_device *dev,
+			    int channel, u16 *value, enum dt9812_gain gain)
 {
+	struct dt9812_private *devpriv = dev->private;
 	struct dt9812_rmw_byte rmw[3];
 	u8 reg[3] = {
 		F020_SFR_ADC0CN,
@@ -542,31 +450,30 @@ static int dt9812_analog_in(struct slot_dt9812 *slot, int channel, u16 *value,
 		F020_SFR_ADC0L
 	};
 	u8 val[3];
-	int result = -ENODEV;
+	int ret;
 
-	down(&slot->mutex);
-	if (!slot->usb)
-		goto exit;
+	down(&devpriv->sem);
 
 	/* 1 select the gain */
-	dt9812_configure_gain(slot->usb, &rmw[0], gain);
+	dt9812_configure_gain(dev, &rmw[0], gain);
 
 	/* 2 set the MUX to select the channel */
-	dt9812_configure_mux(slot->usb, &rmw[1], channel);
+	dt9812_configure_mux(dev, &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)
+	ret = dt9812_rmw_multiple_registers(dev, 3, rmw);
+	if (ret)
 		goto exit;
 
 	/* read the status and ADC */
-	result = dt9812_read_multiple_registers(slot->usb, 3, reg, val);
-	if (result)
+	ret = dt9812_read_multiple_registers(dev, 3, reg, val);
+	if (ret)
 		goto exit;
+
 	/*
 	 * An ADC conversion takes 16 SAR clocks cycles, i.e. about 9us.
 	 * Therefore, between the instant that AD0BUSY was set via
@@ -578,7 +485,7 @@ static int dt9812_analog_in(struct slot_dt9812 *slot, int channel, u16 *value,
 	 */
 	if ((val[0] & (F020_MASK_ADC0CN_AD0INT | F020_MASK_ADC0CN_AD0BUSY)) ==
 	    F020_MASK_ADC0CN_AD0INT) {
-		switch (slot->usb->device) {
+		switch (devpriv->device) {
 		case DT9812_DEVID_DT9812_10:
 			/*
 			 * For DT9812-10V the personality module set the
@@ -594,422 +501,284 @@ static int dt9812_analog_in(struct slot_dt9812 *slot, int channel, u16 *value,
 	}
 
 exit:
-	up(&slot->mutex);
-	return result;
+	up(&devpriv->sem);
+
+	return ret;
 }
 
-static int dt9812_analog_out_shadow(struct slot_dt9812 *slot, int channel,
-				    u16 *value)
+static int dt9812_analog_out(struct comedi_device *dev, int channel, u16 value)
 {
-	int result = -ENODEV;
+	struct dt9812_private *devpriv = dev->private;
+	struct dt9812_rmw_byte rmw[3];
+	int ret;
 
-	down(&slot->mutex);
-	if (slot->usb) {
-		*value = slot->usb->analog_out_shadow[channel];
-		result = 0;
+	down(&devpriv->sem);
+
+	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;
 	}
-	up(&slot->mutex);
+	ret = dt9812_rmw_multiple_registers(dev, 3, rmw);
+	devpriv->ao_shadow[channel] = value;
 
-	return result;
+	up(&devpriv->sem);
+
+	return ret;
 }
 
-static int dt9812_analog_out(struct slot_dt9812 *slot, int channel, u16 value)
+static int dt9812_di_insn_bits(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned int *data)
 {
-	int result = -ENODEV;
+	u8 bits = 0;
+	int ret;
 
-	down(&slot->mutex);
-	if (slot->usb) {
-		struct dt9812_rmw_byte rmw[3];
+	ret = dt9812_digital_in(dev, &bits);
+	if (ret)
+		return ret;
 
-		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;
+	data[1] = bits;
 
-		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;
+	return insn->n;
+}
+
+static int dt9812_do_insn_bits(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned int *data)
+{
+	unsigned int mask = data[0];
+	unsigned int bits = data[1];
+
+	if (mask) {
+		s->state &= ~mask;
+		s->state |= (bits & mask);
+
+		dt9812_digital_out(dev, s->state);
 	}
-	up(&slot->mutex);
 
-	return result;
+	data[1] = s->state;
+
+	return insn->n;
 }
 
-/*
- * USB framework functions
- */
+static int dt9812_ai_insn_read(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned int *data)
+{
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	u16 val = 0;
+	int ret;
+	int i;
 
-static int dt9812_probe(struct usb_interface *interface,
-			const struct usb_device_id *id)
+	for (i = 0; i < insn->n; i++) {
+		ret = dt9812_analog_in(dev, chan, &val, DT9812_GAIN_1);
+		if (ret)
+			return ret;
+		data[i] = val;
+	}
+
+	return insn->n;
+}
+
+static int dt9812_ao_insn_read(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned int *data)
 {
-	int retval = -ENOMEM;
-	struct usb_dt9812 *dev = NULL;
-	struct usb_host_interface *iface_desc;
-	struct usb_endpoint_descriptor *endpoint;
+	struct dt9812_private *devpriv = dev->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
 	int i;
-	u8 fw;
 
-	/* allocate memory for our device state and initialize it */
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (dev == NULL)
-		goto error;
+	down(&devpriv->sem);
+	for (i = 0; i < insn->n; i++)
+		data[i] = devpriv->ao_shadow[chan];
+	up(&devpriv->sem);
+
+	return insn->n;
+}
+
+static int dt9812_ao_insn_write(struct comedi_device *dev,
+				struct comedi_subdevice *s,
+				struct comedi_insn *insn,
+				unsigned int *data)
+{
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	int ret;
+	int i;
 
-	kref_init(&dev->kref);
+	for (i = 0; i < insn->n; i++) {
+		ret = dt9812_analog_out(dev, chan, data[i]);
+		if (ret)
+			return ret;
+	}
 
-	dev->udev = usb_get_dev(interface_to_usbdev(interface));
-	dev->interface = interface;
+	return insn->n;
+}
 
-	/* Check endpoints */
-	iface_desc = interface->cur_altsetting;
+static int dt9812_find_endpoints(struct comedi_device *dev)
+{
+	struct usb_interface *intf = comedi_to_usb_interface(dev);
+	struct usb_host_interface *host = intf->cur_altsetting;
+	struct dt9812_private *devpriv = dev->private;
+	struct usb_endpoint_descriptor *ep;
+	int i;
 
-	if (iface_desc->desc.bNumEndpoints != 5) {
-		dev_err(&interface->dev, "Wrong number of endpoints.\n");
-		retval = -ENODEV;
-		goto error;
+	if (host->desc.bNumEndpoints != 5) {
+		dev_err(dev->class_dev, "Wrong number of endpoints\n");
+		return -ENODEV;
 	}
 
-	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
-		int direction = -1;
-		endpoint = &iface_desc->endpoint[i].desc;
+	for (i = 0; i < host->desc.bNumEndpoints; ++i) {
+		int dir = -1;
+		ep = &host->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);
-
+			/* unused message pipe */
+			dir = USB_DIR_IN;
 			break;
 		case 1:
-			direction = USB_DIR_OUT;
-			dev->command_write.addr = endpoint->bEndpointAddress;
-			dev->command_write.size =
-			    le16_to_cpu(endpoint->wMaxPacketSize);
+			dir = USB_DIR_OUT;
+			devpriv->cmd_wr.addr = ep->bEndpointAddress;
+			devpriv->cmd_wr.size = le16_to_cpu(ep->wMaxPacketSize);
 			break;
 		case 2:
-			direction = USB_DIR_IN;
-			dev->command_read.addr = endpoint->bEndpointAddress;
-			dev->command_read.size =
-			    le16_to_cpu(endpoint->wMaxPacketSize);
+			dir = USB_DIR_IN;
+			devpriv->cmd_rd.addr = ep->bEndpointAddress;
+			devpriv->cmd_rd.size = le16_to_cpu(ep->wMaxPacketSize);
 			break;
 		case 3:
-			direction = USB_DIR_OUT;
-			dev->write_stream.addr = endpoint->bEndpointAddress;
-			dev->write_stream.size =
-			    le16_to_cpu(endpoint->wMaxPacketSize);
+			/* unused write stream */
+			dir = USB_DIR_OUT;
 			break;
 		case 4:
-			direction = USB_DIR_IN;
-			dev->read_stream.addr = endpoint->bEndpointAddress;
-			dev->read_stream.size =
-			    le16_to_cpu(endpoint->wMaxPacketSize);
+			/* unused read stream */
+			dir = USB_DIR_IN;
 			break;
 		}
-		if ((endpoint->bEndpointAddress & USB_DIR_IN) != direction) {
-			dev_err(&interface->dev,
-				"Endpoint has wrong direction.\n");
-			retval = -ENODEV;
-			goto error;
+		if ((ep->bEndpointAddress & USB_DIR_IN) != dir) {
+			dev_err(dev->class_dev,
+				"Endpoint has wrong direction\n");
+			return -ENODEV;
 		}
 	}
-	if (dt9812_read_info(dev, 0, &fw, sizeof(fw)) != 0) {
+	return 0;
+}
+
+static int dt9812_reset_device(struct comedi_device *dev)
+{
+	struct usb_device *usb = comedi_to_usb_dev(dev);
+	struct dt9812_private *devpriv = dev->private;
+	u32 serial;
+	u16 vendor;
+	u16 product;
+	u16 tmp16;
+	u8 tmp8;
+	int ret;
+	int i;
+
+	ret = dt9812_read_info(dev, 0, &tmp8, sizeof(tmp8));
+	if (ret) {
 		/*
 		 * Seems like a configuration reset is necessary if driver is
 		 * reloaded while device is attached
 		 */
-		usb_reset_configuration(dev->udev);
+		usb_reset_configuration(usb);
 		for (i = 0; i < 10; i++) {
-			retval = dt9812_read_info(dev, 1, &fw, sizeof(fw));
-			if (retval == 0) {
-				dev_info(&interface->dev,
-					 "usb_reset_configuration succeeded "
-					 "after %d iterations\n", i);
+			ret = dt9812_read_info(dev, 1, &tmp8, sizeof(tmp8));
+			if (ret == 0)
 				break;
-			}
 		}
-	}
-
-	if (dt9812_read_info(dev, 1, &dev->vendor, sizeof(dev->vendor)) != 0) {
-		dev_err(&interface->dev, "Failed to read vendor.\n");
-		retval = -ENODEV;
-		goto error;
-	}
-	if (dt9812_read_info(dev, 3, &dev->product, sizeof(dev->product)) != 0) {
-		dev_err(&interface->dev, "Failed to read product.\n");
-		retval = -ENODEV;
-		goto error;
-	}
-	if (dt9812_read_info(dev, 5, &dev->device, sizeof(dev->device)) != 0) {
-		dev_err(&interface->dev, "Failed to read device.\n");
-		retval = -ENODEV;
-		goto error;
-	}
-	if (dt9812_read_info(dev, 7, &dev->serial, sizeof(dev->serial)) != 0) {
-		dev_err(&interface->dev, "Failed to read serial.\n");
-		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 */
-	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 */
-		struct slot_dt9812 *first = NULL;
-		struct slot_dt9812 *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);
+		if (ret) {
+			dev_err(dev->class_dev,
+				"unable to reset configuration\n");
+			return ret;
 		}
 	}
-	up(&dt9812_mutex);
-
-	return 0;
 
-error:
-	if (dev)
-		kref_put(&dev->kref, dt9812_delete);
-	return retval;
-}
-
-static void dt9812_disconnect(struct usb_interface *interface)
-{
-	struct usb_dt9812 *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;
+	ret = dt9812_read_info(dev, 1, &vendor, sizeof(vendor));
+	if (ret) {
+		dev_err(dev->class_dev, "failed to read vendor id\n");
+		return ret;
 	}
-	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);
-}
+	vendor = le16_to_cpu(vendor);
 
-static struct usb_driver dt9812_usb_driver = {
-	.name = "dt9812",
-	.probe = dt9812_probe,
-	.disconnect = dt9812_disconnect,
-	.id_table = dt9812_table,
-};
-
-/*
- * Comedi functions
- */
-
-static int dt9812_comedi_open(struct comedi_device *dev)
-{
-	struct comedi_dt9812 *devpriv = dev->private;
-	int result = -ENODEV;
-
-	down(&devpriv->slot->mutex);
-	if (devpriv->slot->usb) {
-		/* We have an attached device, fill in current range info */
-		struct 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 = &range_bipolar10;
-			}
-			break;
-		case 1:{
-				s->maxdata = 4095;
-				s->range_table = &range_unipolar2_5;
-			}
-			break;
-		}
-
-		s = &dev->subdevices[3];
-		s->n_chan = 2;
-		switch (devpriv->slot->usb->device) {
-		case 0:{
-				s->maxdata = 4095;
-				s->range_table = &range_bipolar10;
-			}
-			break;
-		case 1:{
-				s->maxdata = 4095;
-				s->range_table = &range_unipolar2_5;
-			}
-			break;
-		}
-		result = 0;
+	ret = dt9812_read_info(dev, 3, &product, sizeof(product));
+	if (ret) {
+		dev_err(dev->class_dev, "failed to read product id\n");
+		return ret;
 	}
-	up(&devpriv->slot->mutex);
-	return result;
-}
-
-static int dt9812_di_rinsn(struct comedi_device *dev,
-			   struct comedi_subdevice *s, struct comedi_insn *insn,
-			   unsigned int *data)
-{
-	struct comedi_dt9812 *devpriv = dev->private;
-	unsigned int channel = CR_CHAN(insn->chanspec);
-	int n;
-	u8 bits = 0;
-
-	dt9812_digital_in(devpriv->slot, &bits);
-	for (n = 0; n < insn->n; n++)
-		data[n] = ((1 << channel) & bits) != 0;
-	return n;
-}
+	product = le16_to_cpu(product);
 
-static int dt9812_do_winsn(struct comedi_device *dev,
-			   struct comedi_subdevice *s, struct comedi_insn *insn,
-			   unsigned int *data)
-{
-	struct comedi_dt9812 *devpriv = dev->private;
-	unsigned int channel = CR_CHAN(insn->chanspec);
-	int n;
-	u8 bits = 0;
-
-	dt9812_digital_out_shadow(devpriv->slot, &bits);
-	for (n = 0; n < insn->n; n++) {
-		u8 mask = 1 << channel;
-
-		bits &= ~mask;
-		if (data[n])
-			bits |= mask;
+	ret = dt9812_read_info(dev, 5, &tmp16, sizeof(tmp16));
+	if (ret) {
+		dev_err(dev->class_dev, "failed to read device id\n");
+		return ret;
 	}
-	dt9812_digital_out(devpriv->slot, bits);
-	return n;
-}
+	devpriv->device = le16_to_cpu(tmp16);
 
-static int dt9812_ai_rinsn(struct comedi_device *dev,
-			   struct comedi_subdevice *s, struct comedi_insn *insn,
-			   unsigned int *data)
-{
-	struct comedi_dt9812 *devpriv = dev->private;
-	unsigned int channel = CR_CHAN(insn->chanspec);
-	int n;
-
-	for (n = 0; n < insn->n; n++) {
-		u16 value = 0;
-
-		dt9812_analog_in(devpriv->slot, channel, &value, DT9812_GAIN_1);
-		data[n] = value;
+	ret = dt9812_read_info(dev, 7, &serial, sizeof(serial));
+	if (ret) {
+		dev_err(dev->class_dev, "failed to read serial number\n");
+		return ret;
 	}
-	return n;
-}
+	serial = le32_to_cpu(serial);
 
-static int dt9812_ao_rinsn(struct comedi_device *dev,
-			   struct comedi_subdevice *s, struct comedi_insn *insn,
-			   unsigned int *data)
-{
-	struct comedi_dt9812 *devpriv = dev->private;
-	unsigned int channel = CR_CHAN(insn->chanspec);
-	int n;
-	u16 value;
-
-	for (n = 0; n < insn->n; n++) {
-		value = 0;
-		dt9812_analog_out_shadow(devpriv->slot, channel, &value);
-		data[n] = value;
-	}
-	return n;
-}
+	/* let the user know what node this device is now attached to */
+	dev_info(dev->class_dev, "USB DT9812 (%4.4x.%4.4x.%4.4x) #0x%8.8x\n",
+		 vendor, product, devpriv->device, serial);
 
-static int dt9812_ao_winsn(struct comedi_device *dev,
-			   struct comedi_subdevice *s, struct comedi_insn *insn,
-			   unsigned int *data)
-{
-	struct comedi_dt9812 *devpriv = dev->private;
-	unsigned int channel = CR_CHAN(insn->chanspec);
-	int n;
+	if (devpriv->device != DT9812_DEVID_DT9812_10 &&
+	    devpriv->device != DT9812_DEVID_DT9812_2PT5) {
+		dev_err(dev->class_dev, "Unsupported device!\n");
+		return -EINVAL;
+	}
 
-	for (n = 0; n < insn->n; n++)
-		dt9812_analog_out(devpriv->slot, channel, data[n]);
-	return n;
+	return 0;
 }
 
-static int dt9812_attach(struct comedi_device *dev, struct comedi_devconfig *it)
+static int dt9812_auto_attach(struct comedi_device *dev,
+			      unsigned long context)
 {
-	struct comedi_dt9812 *devpriv;
-	int i;
+	struct usb_interface *intf = comedi_to_usb_interface(dev);
+	struct dt9812_private *devpriv;
 	struct comedi_subdevice *s;
+	bool is_unipolar;
 	int ret;
 
 	devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL);
@@ -1017,125 +786,107 @@ static int dt9812_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		return -ENOMEM;
 	dev->private = devpriv;
 
-	/*
-	 * Special open routine, since USB unit may be unattached at
-	 * comedi_config time, hence range can not be determined
-	 */
-	dev->open = dt9812_comedi_open;
+	sema_init(&devpriv->sem, 1);
+	usb_set_intfdata(intf, devpriv);
 
-	devpriv->serial = it->options[0];
+	ret = dt9812_find_endpoints(dev);
+	if (ret)
+		return ret;
+
+	ret = dt9812_reset_device(dev);
+	if (ret)
+		return ret;
+
+	is_unipolar = (devpriv->device == DT9812_DEVID_DT9812_2PT5);
 
 	ret = comedi_alloc_subdevices(dev, 4);
 	if (ret)
 		return ret;
 
-	/* digital input subdevice */
+	/* 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->type		= COMEDI_SUBD_DI;
+	s->subdev_flags	= SDF_READABLE;
+	s->n_chan	= 8;
+	s->maxdata	= 1;
+	s->range_table	= &range_digital;
+	s->insn_bits	= dt9812_di_insn_bits;
+
+	/* 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->type		= COMEDI_SUBD_DO;
+	s->subdev_flags	= SDF_WRITEABLE;
+	s->n_chan	= 8;
+	s->maxdata	= 1;
+	s->range_table	= &range_digital;
+	s->insn_bits	= dt9812_do_insn_bits;
+
+	/* 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 = NULL;
-	s->insn_read = &dt9812_ai_rinsn;
-
-	/* analog output subdevice */
+	s->type		= COMEDI_SUBD_AI;
+	s->subdev_flags	= SDF_READABLE | SDF_GROUND;
+	s->n_chan	= 8;
+	s->maxdata	= 0x0fff;
+	s->range_table	= is_unipolar ? &range_unipolar2_5 : &range_bipolar10;
+	s->insn_read	= dt9812_ai_insn_read;
+
+	/* 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 = NULL;
-	s->insn_write = &dt9812_ao_winsn;
-	s->insn_read = &dt9812_ao_rinsn;
-
-	dev_info(dev->class_dev, "successfully attached to dt9812.\n");
-
-	down(&dt9812_mutex);
-	/* Find a slot for the comedi device */
-	{
-		struct slot_dt9812 *first = NULL;
-		struct slot_dt9812 *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);
+	s->type		= COMEDI_SUBD_AO;
+	s->subdev_flags	= SDF_WRITEABLE;
+	s->n_chan	= 2;
+	s->maxdata	= 0x0fff;
+	s->range_table	= is_unipolar ? &range_unipolar2_5 : &range_bipolar10;
+	s->insn_write	= dt9812_ao_insn_write;
+	s->insn_read	= dt9812_ao_insn_read;
+
+	devpriv->ao_shadow[0] = is_unipolar ? 0x0000 : 0x0800;
+	devpriv->ao_shadow[1] = is_unipolar ? 0x0000 : 0x0800;
 
 	return 0;
 }
 
 static void dt9812_detach(struct comedi_device *dev)
 {
-	/* Nothing to cleanup */
-}
+	struct usb_interface *intf = comedi_to_usb_interface(dev);
+	struct dt9812_private *devpriv = dev->private;
 
-static struct comedi_driver dt9812_comedi_driver = {
-	.module = THIS_MODULE,
-	.driver_name = "dt9812",
-	.attach = dt9812_attach,
-	.detach = dt9812_detach,
-};
+	if (!devpriv)
+		return;
 
-static int __init usb_dt9812_init(void)
-{
-	int i;
+	down(&devpriv->sem);
 
-	/* Initialize all driver slots */
-	for (i = 0; i < DT9812_NUM_SLOTS; i++) {
-		sema_init(&dt9812[i].mutex, 1);
-		dt9812[i].serial = 0;
-		dt9812[i].usb = NULL;
-		dt9812[i].comedi = NULL;
-	}
-	dt9812[12].serial = 0x0;
+	usb_set_intfdata(intf, NULL);
 
-	return comedi_usb_driver_register(&dt9812_comedi_driver,
-						&dt9812_usb_driver);
+	up(&devpriv->sem);
 }
 
-static void __exit usb_dt9812_exit(void)
+static struct comedi_driver dt9812_driver = {
+	.driver_name	= "dt9812",
+	.module		= THIS_MODULE,
+	.auto_attach	= dt9812_auto_attach,
+	.detach		= dt9812_detach,
+};
+
+static int dt9812_usb_probe(struct usb_interface *intf,
+			    const struct usb_device_id *id)
 {
-	comedi_usb_driver_unregister(&dt9812_comedi_driver, &dt9812_usb_driver);
+	return comedi_usb_auto_config(intf, &dt9812_driver, id->driver_info);
 }
 
-module_init(usb_dt9812_init);
-module_exit(usb_dt9812_exit);
+static const struct usb_device_id dt9812_usb_table[] = {
+	{ USB_DEVICE(0x0867, 0x9812) },
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, dt9812_usb_table);
+
+static struct usb_driver dt9812_usb_driver = {
+	.name		= "dt9812",
+	.id_table	= dt9812_usb_table,
+	.probe		= dt9812_usb_probe,
+	.disconnect	= comedi_usb_auto_unconfig,
+};
+module_comedi_usb_driver(dt9812_driver, dt9812_usb_driver);
 
 MODULE_AUTHOR("Anders Blomdell <anders.blomdell@control.lth.se>");
 MODULE_DESCRIPTION("Comedi DT9812 driver");