Index: uspace/srv/hid/isdv4_tablet/isdv4.c
===================================================================
--- uspace/srv/hid/isdv4_tablet/isdv4.c	(revision c4c60250a236ed30397cd89ce5cea5eaf59cfba5)
+++ uspace/srv/hid/isdv4_tablet/isdv4.c	(revision 74017cef2e4edaf9405cf38ba4b0958f664e700c)
@@ -27,10 +27,10 @@
  */
 
-#include <char_dev_iface.h>
 #include <errno.h>
+#include <io/chardev.h>
+#include <mem.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
-#include <mem.h>
 #include <thread.h>
 
@@ -298,9 +298,12 @@
 	bool reading = true;
 	while (reading) {
-		ssize_t read = char_dev_read(state->sess, state->buf + state->buf_end,
-		    state->buf_size - state->buf_end);
-		if (read < 0)
+		size_t nread;
+		int rc;
+
+		rc = chardev_read(state->chardev, state->buf + state->buf_end,
+		    state->buf_size - state->buf_end, &nread);
+		if (rc != EOK && nread == 0)
 			return EIO;
-		state->buf_end += read;
+		state->buf_end += nread;
 
 		size_t i = 0;
@@ -357,7 +360,12 @@
 	return EOK;
 }
-static bool write_command(async_sess_t *sess, uint8_t command)
-{
-	return char_dev_write(sess, &command, 1) == 1;
+
+static bool write_command(chardev_t *chardev, uint8_t command)
+{
+	int rc;
+	size_t nwr;
+
+	rc = chardev_write(chardev, &command, 1, &nwr);
+	return rc == EOK;
 }
 
@@ -365,9 +373,22 @@
     isdv4_event_fn event_fn)
 {
+	chardev_t *chardev;
+	int rc;
+
+	rc = chardev_open(sess, &chardev);
+	if (rc != EOK)
+		return rc;
+
 	memset(state, 0, sizeof(isdv4_state_t));
+
 	state->sess = sess;
+	state->chardev = chardev;
+
 	state->buf = malloc(BUF_SIZE);
-	if (state->buf == NULL)
+	if (state->buf == NULL) {
+		chardev_close(chardev);
 		return ENOMEM;
+	}
+
 	state->buf_size = BUF_SIZE;
 	state->emit_event_fn = event_fn;
@@ -377,5 +398,5 @@
 int isdv4_init_tablet(isdv4_state_t *state)
 {
-	if (!write_command(state->sess, CMD_STOP))
+	if (!write_command(state->chardev, CMD_STOP))
 		return EIO;
 
@@ -383,5 +404,5 @@
 
 	// FIXME: Read all possible garbage before sending commands
-	if (!write_command(state->sess, CMD_QUERY_STYLUS))
+	if (!write_command(state->chardev, CMD_QUERY_STYLUS))
 		return EIO;
 
@@ -390,5 +411,5 @@
 		return rc;
 
-	if (!write_command(state->sess, CMD_QUERY_TOUCH))
+	if (!write_command(state->chardev, CMD_QUERY_TOUCH))
 		return EIO;
 
@@ -397,5 +418,5 @@
 		return rc;
 
-	if (!write_command(state->sess, CMD_START))
+	if (!write_command(state->chardev, CMD_START))
 		return EIO;
 
Index: uspace/srv/hid/isdv4_tablet/isdv4.h
===================================================================
--- uspace/srv/hid/isdv4_tablet/isdv4.h	(revision c4c60250a236ed30397cd89ce5cea5eaf59cfba5)
+++ uspace/srv/hid/isdv4_tablet/isdv4.h	(revision 74017cef2e4edaf9405cf38ba4b0958f664e700c)
@@ -31,4 +31,5 @@
 
 #include <async.h>
+#include <io/chardev.h>
 
 typedef struct isdv4_event isdv4_event_t;
@@ -58,6 +59,8 @@
 	bool finger1_pressed; /* Reported as touch button 1 */
 
-	/* Session to the serial device */
+	/** Session with the serial device */
 	async_sess_t *sess;
+	/** Character device */
+	chardev_t *chardev;
 
 	/* Receive buffer state */
@@ -66,5 +69,5 @@
 	size_t buf_end;
 
-	/* Callbacks */
+	/** Callbacks */
 	isdv4_event_fn emit_event_fn;
 } isdv4_state_t;