diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index c8365fb20b4f65c85545dc9e2a5aef29c8623069..6b188e8008e45eaf2cd82c4a813e51f295c948d8 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -98,11 +98,6 @@
 #define BRANCH_MAIN			0xCC
 #define BRANCH_AUX			0x33
 
-/*
- * Duration of the strong pull-up pulse in milliseconds.
- */
-#define PULLUP_PULSE_DURATION		750
-
 /* Status flags */
 #define ST_SPUA				0x01  /* Strong Pull-up is active */
 #define ST_PRGA				0x02  /* 12V programming pulse is being generated */
@@ -131,6 +126,11 @@ struct ds_device
 
 	int			ep[NUM_EP];
 
+	/* Strong PullUp
+	 * 0: pullup not active, else duration in milliseconds
+	 */
+	int			spu_sleep;
+
 	struct w1_bus_master	master;
 };
 
@@ -192,7 +192,7 @@ static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
 
 	return err;
 }
-#if 0
+
 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
 {
 	int err;
@@ -207,7 +207,7 @@ static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
 
 	return err;
 }
-#endif
+
 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
 {
 	int err;
@@ -294,14 +294,6 @@ static int ds_recv_status(struct ds_device *dev, struct ds_status *st)
 		if (count < 0)
 			return err;
 	}
-#if 0
-	if (st->status & ST_IDLE) {
-		printk(KERN_INFO "Resetting pulse after ST_IDLE.\n");
-		err = ds_start_pulse(dev, PULLUP_PULSE_DURATION);
-		if (err)
-			return err;
-	}
-#endif
 
 	return err;
 }
@@ -472,32 +464,26 @@ static int ds_set_speed(struct ds_device *dev, int speed)
 }
 #endif  /*  0  */
 
-static int ds_start_pulse(struct ds_device *dev, int delay)
+static int ds_set_pullup(struct ds_device *dev, int delay)
 {
 	int err;
 	u8 del = 1 + (u8)(delay >> 4);
-	struct ds_status st;
-
-#if 0
-	err = ds_stop_pulse(dev, 10);
-	if (err)
-		return err;
-
-	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE);
-	if (err)
-		return err;
-#endif
-	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
-	if (err)
-		return err;
 
-	err = ds_send_control(dev, COMM_PULSE | COMM_IM | COMM_F, 0);
+	dev->spu_sleep = 0;
+	err = ds_send_control_mode(dev, MOD_PULSE_EN, delay ? PULSE_SPUE : 0);
 	if (err)
 		return err;
 
-	mdelay(delay);
+	if (delay) {
+		err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
+		if (err)
+			return err;
 
-	ds_wait_status(dev, &st);
+		/* Just storing delay would not get the trunication and
+		 * roundup.
+		 */
+		dev->spu_sleep = del<<4;
+	}
 
 	return err;
 }
@@ -558,6 +544,9 @@ static int ds_write_byte(struct ds_device *dev, u8 byte)
 	if (err)
 		return err;
 
+	if (dev->spu_sleep)
+		msleep(dev->spu_sleep);
+
 	err = ds_wait_status(dev, &st);
 	if (err)
 		return err;
@@ -566,8 +555,6 @@ static int ds_write_byte(struct ds_device *dev, u8 byte)
 	if (err < 0)
 		return err;
 
-	ds_start_pulse(dev, PULLUP_PULSE_DURATION);
-
 	return !(byte == rbyte);
 }
 
@@ -603,7 +590,7 @@ static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
 	if (err < 0)
 		return err;
 
-	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | COMM_SPU, len);
+	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
 	if (err)
 		return err;
 
@@ -630,14 +617,15 @@ static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
 	if (err)
 		return err;
 
+	if (dev->spu_sleep)
+		msleep(dev->spu_sleep);
+
 	ds_wait_status(dev, &st);
 
 	err = ds_recv_data(dev, buf, len);
 	if (err < 0)
 		return err;
 
-	ds_start_pulse(dev, PULLUP_PULSE_DURATION);
-
 	return !(err == len);
 }
 
@@ -803,6 +791,16 @@ static u8 ds9490r_reset(void *data)
 	return 0;
 }
 
+static u8 ds9490r_set_pullup(void *data, int delay)
+{
+	struct ds_device *dev = data;
+
+	if (ds_set_pullup(dev, delay))
+		return 1;
+
+	return 0;
+}
+
 static int ds_w1_init(struct ds_device *dev)
 {
 	memset(&dev->master, 0, sizeof(struct w1_bus_master));
@@ -816,6 +814,7 @@ static int ds_w1_init(struct ds_device *dev)
 	dev->master.read_block	= &ds9490r_read_block;
 	dev->master.write_block	= &ds9490r_write_block;
 	dev->master.reset_bus	= &ds9490r_reset;
+	dev->master.set_pullup	= &ds9490r_set_pullup;
 
 	return w1_add_master_device(&dev->master);
 }
@@ -839,6 +838,7 @@ static int ds_probe(struct usb_interface *intf,
 		printk(KERN_INFO "Failed to allocate new DS9490R structure.\n");
 		return -ENOMEM;
 	}
+	dev->spu_sleep = 0;
 	dev->udev = usb_get_dev(udev);
 	if (!dev->udev) {
 		err = -ENOMEM;