bes2600: remove userspace /dev/bes2600 character device interface

bes_chardev.c implemented a custom character device at /dev/bes2600 with
its own parser and command-dispatch table, exposing operations such as
'wifi on|off', 'bt on|off', 'change_fw_type <n>', 'bt_wakeup',
'bt_sleep', and 'wakeup_read_flag'. None of these surfaces are used by
the in-tree driver - every kernel call site consumes the internal state
accessors (bes2600_chrdev_is_signal_mode, bes2600_chrdev_get_fw_type,
etc) directly, not through the cdev.

The cdev interface is a standing upstream blocker for two reasons:

  1. Drivers under drivers/staging/ and drivers/net/wireless/ are
     expected to expose tuning via the firmware/nl80211/debugfs
     infrastructure rather than a private /dev node with an ad-hoc
     parser.

  2. The cdev handlers keep a global bes_cdev singleton alive whose
     ->cdev, ->dev_id, ->class and ->device pointers exist only to be
     torn down; they add no functionality that nl80211 or rfkill do
     not already provide (wifi/bt on-off, module_param for fw_type).

Remove the userspace interface:

  - open / read / write / release file_operations handlers and the
    bes2600_chardev_fops instance
  - bes2600_op_* command handlers and bes2600_op_map_tab dispatcher
  - bes2600_get_cmd_and_ifname / bes2600_recyle_cmd_and_ifname_mem
    string helpers
  - bes2600_load_uevent (its only caller was
    bes2600_chrdev_wifi_force_close_work informing userspace of a
    state it already gates via rfkill; that snprintf +
    kobject_uevent_env block is gone too, the kernel-side
    halt_device + switch_wifi(0) + chrdev_check_system_close
    sequence remains)
  - alloc_chrdev_region / cdev_init / cdev_add / class_create /
    device_create in bes2600_chrdev_init plus the fail1/fail2/fail3
    unwind labels
  - cdev_del / unregister_chrdev_region / device_destroy /
    class_destroy in bes2600_chrdev_free
  - cdev/dev_id/major/minor/class/device fields in struct bes_cdev

What remains (unchanged behaviour):

  - fw_type module parameter - the primary user-facing knob for
    signal/no-signal/BT mode switch
  - All in-kernel bes2600_chrdev_* accessor functions called from
    bes2600_sdio.c, bes_pwr.c, sta.c, bh.c, main.c, wsm.c, and
    wifi_testmode_cmd.c (13 call sites)
  - bes2600_chrdev_init / bes2600_chrdev_free as state-init / teardown
    for the remaining bes_cdev state (waitqueues, workqueues, flags)
  - DPD management (bes2600_chrdev_get_dpd_buffer / update / free)
  - wifi_force_close worker, system-close logic, bus-probe state
    machine

Tested-on: PineTab2 (BES2600WM + RK3566) running linux-pinetab2
6.19.10-danctnix1-1. Driver continues to associate and pass traffic;
no kernel messages related to the cdev absence. Users that previously
wrote to /dev/bes2600 should switch to the fw_type module parameter
or (future patch c4) nl80211 testmode commands.

Follow-ups:

  - c3.1: thread struct device * through bes2600_chrdev_is_signal_mode
    and friends so the global bes2600_cdev singleton can be dropped
    and the accessors scale to multi-device scenarios.
  - c4:   enable CONFIG_BES2600_TESTMODE and route nl80211 testmode
    commands to the firmware's patch_wifi_testMode entry.

Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>

bes2600/bes_chardev.c

@@ -43,12 +43,6 @@ enum bus_probe_state {
 };
 
 struct bes_cdev {
-	struct cdev cdev;
-	dev_t dev_id;
-	int major;
-	int minor;
-	struct class *class;
-	struct device *device;
 	atomic_t num_proc;
 	wait_queue_head_t open_wq;
 	spinlock_t status_lock;
@@ -249,351 +243,18 @@ int bes2600_switch_bt(bool on)
 	return ret;
 }
 
-static int bes2600_get_cmd_and_ifname(const char *str, char **result)
-{
-	int cmd_len = 0;
-	int ifname_len = 0;
-	char *sp = NULL;
-	char *tmp_ptr = NULL;
-	char *cmd_ptr = NULL;
-
-	/* check if input arguments is valid */
-	if (!str || strncmp(str, "ifname:", 7) != 0)
-		return -1;
-
-	sp = strchr(str, ' ');
-	if (strncmp(sp + 1, "cmd:", 4) != 0)
-		return -1;
-
-	/* extract interface name */
-	ifname_len = sp - str - 7;
-	tmp_ptr = kmalloc(ifname_len + 1, GFP_KERNEL);
-	if (!tmp_ptr) {
-		return -2;
-	}
-
-	strncpy(tmp_ptr, str+7, ifname_len);
-	tmp_ptr[ifname_len] = '\0';
-	result[0] = tmp_ptr;
-
-	/* get command length */
-	cmd_ptr = strstr(str, "cmd:");
-	cmd_ptr += 4;
-	sp = strchr(cmd_ptr, ' ');
-	if (!sp) {	/* the command don't have any parameter */
-		cmd_len = strlen(cmd_ptr);
-		if (cmd_ptr[cmd_len - 1] == '\n')
-			--cmd_len;
-	} else {	/* the command have one or more parameter */
-		cmd_len = sp - cmd_ptr;
-	}
-
-	/* copy command to out buffer */
-	tmp_ptr = kmalloc( cmd_len + 1, GFP_KERNEL);
-	if (!tmp_ptr) {
-		kfree(result[0]);
-		result[0] = NULL;
-		return -3;
-	}
-
-	strncpy(tmp_ptr, cmd_ptr, cmd_len);
-	tmp_ptr[cmd_len] = '\0';
-	result[1] = tmp_ptr;
-
-	return 0;
-}
-
-static void bes2600_recyle_cmd_and_ifname_mem(char **info)
-{
-	if (info[0]) {
-		kfree(info[0]);
-		info[0] = NULL;
-	}
-
-	if (info[1]) {
-		kfree(info[1]);
-		info[1] = NULL;
-	}
-
-}
-
-static int bes2600_op_default_handler(const char *str)
-{
-	char *info[2] = {0};
-
-	if (bes2600_get_cmd_and_ifname(str, info) == 0) {
-		bes_devel("cmd(%s) on %s not handled\n", info[1], info[0]);
-	} else {
-		bes_err("%s get command fail, the origin string is %s\n", __func__, str);
-	}
-
-	bes2600_recyle_cmd_and_ifname_mem(info);
-
-	return 0;
-}
-
-static int bes2600_op_wifi_bt_on_off(const char *str)
-{
-	char *info[2] = {0};
-	int ret = 0;
-	enum wait_state wait_state;
-	enum bus_probe_state probe_state;
-	unsigned long status = 0;
-
-	spin_lock(&bes2600_cdev.status_lock);
-	probe_state = bes2600_cdev.bus_probe;
-	wait_state = bes2600_cdev.wait_state;
-	spin_unlock(&bes2600_cdev.status_lock);
-
-	/* only work for wifi signal mode */
-	if (bes2600_cdev.fw_type != BES2600_FW_TYPE_WIFI_SIGNAL)
-		return -EFAULT;
-
-	/* wait bus probe operation end */
-	if (probe_state == BES2600_BUS_PROBE_START) {
-		bes_devel("wait bus probe operation end\n");
-		status = wait_event_timeout(bes2600_cdev.probe_done_wq,
-					(bes2600_cdev.bus_probe > BES2600_BUS_PROBE_START),
-					HZ);
-		WARN_ON(status <= 0);
-	}
-
-	/* must wait previous operation end in critical section */
-	if (wait_state != BES2600_BOOT_WAIT_NONE) {
-		bes_devel("wait previous operation end\n");
-		status = wait_event_timeout(bes2600_cdev.probe_done_wq,
-					(bes2600_cdev.wait_state == BES2600_BOOT_WAIT_NONE),
-					HZ * 8);
-		WARN_ON(status <= 0);
-	}
-
-	/* if dpd calibration is doing, modify wifi and bt state directly */
-	spin_lock(&bes2600_cdev.status_lock);
-	if (bes2600_cdev.bus_probe == BES2600_BUS_PROBE_OK && !bes2600_cdev.dpd_calied) {
-		if (bes2600_get_cmd_and_ifname(str, info) == 0) {
-			if (strncmp(info[1], "WIFI_ON", 7) == 0) {
-				bes2600_cdev.wifi_opened = true;
-			} else if (strncmp(info[1], "WIFI_OFF", 8) == 0) {
-				bes2600_cdev.wifi_opened = false;
-			} else if (strncmp(info[1], "BT_ON", 5) == 0) {
-				bes2600_cdev.bt_opened = true;
-				bes2600_cdev.bton_pending = true;
-			} else if (strncmp(info[1], "BT_OFF", 6) == 0) {
-				bes2600_cdev.bt_opened = false;
-				bes2600_cdev.bton_pending = false;
-			}
-		}
-		bes2600_recyle_cmd_and_ifname_mem(info);
-		spin_unlock(&bes2600_cdev.status_lock);
-
-		/* wait probe done event */
-		status = wait_event_timeout(bes2600_cdev.probe_done_wq,
-				bes2600_bootup_end(), HZ * 8);
-		WARN_ON(status <= 0);
-
-		return (status <= 0 || bes2600_chrdev_is_bus_error()) ? -EFAULT : 0;
-	}
-	spin_unlock(&bes2600_cdev.status_lock);
-
-	/* process wifi/bt on/off operation */
-	if (bes2600_get_cmd_and_ifname(str, info) == 0) {
-		if (strncmp(info[1], "WIFI_ON", 7) == 0) {
-			ret = bes2600_switch_wifi(1);
-		} else if (strncmp(info[1], "WIFI_OFF", 8) == 0) {
-			ret = bes2600_switch_wifi(0);
-		} else if (strncmp(info[1], "BT_ON", 5) == 0) {
-			ret = bes2600_switch_bt(1);
-		} else if (strncmp(info[1], "BT_OFF", 6) == 0) {
-			ret = bes2600_switch_bt(0);
-		}
-	}
-
-	if (!ret && bes2600_chrdev_check_system_close())
-		ret = bes2600_chrdev_do_system_close(bes2600_cdev.sbus_ops,
-						bes2600_cdev.sbus_priv);
-
-	bes2600_recyle_cmd_and_ifname_mem(info);
-
-	return ret ;
-}
 
 
-static int bes2600_op_change_fw_type(const char *str)
-{
-	int ret = 0;
-	int temp = 0;
-	long status = 0;
-	char *cmd_ptr = NULL;
-	char fw_type[5] = {0};
-	bool sys_closed = bes2600_chrdev_check_system_close();
-
-	bes_devel("%s is called, arg:%s\n", __func__, str);
-
-	if (!bes2600_cdev.sbus_ops->power_switch && !bes2600_cdev.sbus_ops->reboot)
-		return -EPERM;
-
-	/* check if user input is valid */
-	cmd_ptr = strstr(str, "CHANGE_FW_TYPE ");
-	if (strlen(str) < 16 || !cmd_ptr) {
-		bes_err("the format of \"%s\" is error\n", str);
-		return -EINVAL;
-	}
-
-	/* convert fw_type from string to int */
-	strncpy(fw_type, cmd_ptr + 14, 4);
-	fw_type[0] = '+';
-	ret = kstrtoint(fw_type, 10, &temp);
-	if (ret < 0) {
-		bes_err("%s parse error\n", __func__);
-		return -EINVAL;
-	}
-
-	/* no need to realod firmware if new fw_type is equal to the old */
-	if (temp == bes2600_cdev.fw_type ) {
-		bes_devel("fw type is equal\n");
-		return 0;
-	}
-
-	/* close wifi net device */
-	if (bes2600_cdev.sbus_priv
-	    && bes2600_is_net_dev_created(bes2600_cdev.sbus_priv)) {
-		bes2600_unregister_net_dev(bes2600_cdev.sbus_priv);
-	}
-
-	/* update firmware type */
-	bes2600_cdev.fw_type = temp;
-	bes2600_chrdev_update_signal_mode();
-
-	if (!sys_closed) {
-		/* close device to call disconnect function */
-		if (bes2600_cdev.sbus_ops->power_switch)
-			bes2600_cdev.sbus_ops->power_switch(bes2600_cdev.sbus_priv, 0);
-		else if (bes2600_cdev.sbus_ops->reboot)
-			bes2600_cdev.sbus_ops->reboot(bes2600_cdev.sbus_priv);
-	}
-
-	if (bes2600_cdev.sbus_ops->reboot)
-		bes2600_chrdev_start_bus_probe();
-
-	/* wait disconnect event */
-	status = wait_event_timeout(bes2600_cdev.probe_done_wq, (bes2600_cdev.sbus_priv == NULL), HZ * 10);
-	WARN_ON(status <= 0);
-
-	if (bes2600_cdev.dpd_calied
-	   && bes2600_chrdev_check_system_close()) {
-		bes_devel("no need to reload firmware\n");
-		return 0;
-	}
-
-	bes_devel("reload firmware...\n");
-	/* power on device to call probe function */
-	if (bes2600_cdev.sbus_ops->power_switch)
-		bes2600_cdev.sbus_ops->power_switch(NULL, 1);
-
-	/* wait probe done event */
-	status = wait_event_timeout(bes2600_cdev.probe_done_wq,
-			bes2600_bootup_end(), HZ * 10);
-	WARN_ON(status <= 0);
-
-	ret = (status <= 0 || bes2600_chrdev_is_bus_error()) ? -1 : 0;
 
 
-	return ret;
-}
 
-static int bes2600_op_bt_wakeup(const char *str)
-{
-	int ret = 0;
-	unsigned long status = 0;
 
-	spin_lock(&bes2600_cdev.status_lock);
-	if (!bes2600_cdev.bt_opened) {
-		spin_unlock(&bes2600_cdev.status_lock);
-		return -EFAULT;
-	}
-	spin_unlock(&bes2600_cdev.status_lock);
 
-	/* wait probe done event */
-	status = wait_event_timeout(bes2600_cdev.probe_done_wq,
-			bes2600_bootup_end(), HZ * 8);
-	if (status <= 0 || bes2600_chrdev_is_bus_error())
-		return -EFAULT;
 
-	bes_devel("bes2600 wakeup bt.\n");
-	ret = bes2600_chrdev_switch_subsys(GPIO_WAKE_FLAG_BT_LP_ON, SUBSYSTEM_BT_LP, true);
-
-	return ret;
-}
-
-static int bes2600_op_bt_sleep(const char *str)
-{
-	int ret = 0;
-	unsigned long status = 0;
-
-	spin_lock(&bes2600_cdev.status_lock);
-	if (!bes2600_cdev.bt_opened) {
-		spin_unlock(&bes2600_cdev.status_lock);
-		return -EFAULT;
-	}
-	spin_unlock(&bes2600_cdev.status_lock);
-
-	/* wait probe done event */
-	status = wait_event_timeout(bes2600_cdev.probe_done_wq,
-			bes2600_bootup_end(), HZ * 8);
-	if (status <= 0 || bes2600_chrdev_is_bus_error())
-		return -EFAULT;
-
-	bes_devel("bes2600 allow bt sleep.\n");
-	ret = bes2600_chrdev_switch_subsys(GPIO_WAKE_FLAG_BT_LP_OFF, SUBSYSTEM_BT_LP, false);
-
-	return ret;
-}
-
-static int bes2600_op_set_wakeup_read_flag(const char *str)
-{
-	bes_devel("%s is called, arg:%s\n", __func__, str);
-	spin_lock(&bes2600_cdev.status_lock);
-	bes2600_cdev.read_flag = BES_CDEV_READ_WAKEUP_STATE;
-	spin_unlock(&bes2600_cdev.status_lock);
-
-	return 0;
-}
 
 #ifdef FW_DOWNLOAD_UART_DAEMON
-int bes2600_load_uevent(char *env[])
-{
-	return kobject_uevent_env(&bes2600_cdev.device->kobj, KOBJ_CHANGE, env);
-}
 #endif
 
-static struct bes2600_op_map bes2600_op_map_tab[] ={
-	/*op			op_len	handler				*/
-	{"P2P_SET_NOA", 	11,	bes2600_op_default_handler},
-	{"P2P_SET_PS", 		10,	bes2600_op_default_handler},
-	{"SET_AP_WPS_P2P_IE",	17, 	bes2600_op_default_handler},
-	{"LINKSPEED", 		9,	bes2600_op_default_handler},
-	{"RSSI",		4,	bes2600_op_default_handler},
-	{"GETBAND", 		7,	bes2600_op_default_handler},
-	{"WLS_BATCHING", 	12,	bes2600_op_default_handler},
-	{"MACADDR",		7,	bes2600_op_default_handler},
-	{"RXFILTER-START",	14,	bes2600_op_default_handler},
-	{"RXFILTER-STOP",	13,	bes2600_op_default_handler},
-	{"RXFILTER-ADD",	12,	bes2600_op_default_handler},
-	{"RXFILTER-REMOVE",	15,	bes2600_op_default_handler},
-	{"BTCOEXMODE",		10,	bes2600_op_default_handler},
-	{"BTCOEXSCAN-START",	16,	bes2600_op_default_handler},
-	{"BTCOEXSCAN-STOP",	15,	bes2600_op_default_handler},
-	{"SETSUSPENDMODE",	14,	bes2600_op_default_handler},
-	{"COUNTRY",		7,	bes2600_op_default_handler},
-	{"WIFI_ON", 		7,	bes2600_op_wifi_bt_on_off},
-	{"WIFI_OFF", 		8,	bes2600_op_wifi_bt_on_off},
-	{"BT_ON", 		5,	bes2600_op_wifi_bt_on_off},
-	{"BT_OFF", 		6,	bes2600_op_wifi_bt_on_off},
-	{"CHANGE_FW_TYPE",	14,	bes2600_op_change_fw_type},
-	{"BT_WAKEUP",		9,	bes2600_op_bt_wakeup},
-	{"BT_SLEEP",		8,	bes2600_op_bt_sleep},
-	{"WAKEUP_STATE",	12,	bes2600_op_set_wakeup_read_flag},
-};
 
 static int bes2600_chrdev_check_system_close_internal(void)
 {
@@ -603,123 +264,10 @@ static int bes2600_chrdev_check_system_close_internal(void)
 		&& (bes2600_cdev.wifi_opened == false);
 }
 
-static int bes2600_chrdev_open(struct inode *inode, struct file *filp)
-{
-	if (atomic_read(&bes2600_cdev.num_proc) > 0) {
-		wait_event_timeout(bes2600_cdev.open_wq,
-			(atomic_read(&bes2600_cdev.num_proc) == 0),
-			MAX_SCHEDULE_TIMEOUT);
-	}
 
-	bes_devel("bes2600 char device is opened\n");
-	atomic_inc(&bes2600_cdev.num_proc);
 
-        return 0;
-}
 
-static ssize_t bes2600_chrdev_read(struct file *file, char __user *user_buf,
-			     size_t count, loff_t *ppos)
-{
-	char buf[64] = {0};
-	unsigned int len;
-	long status = 0;
 
-	switch (bes2600_cdev.read_flag) {
-	case BES_CDEV_READ_WAKEUP_STATE:
-		if (bes2600_chrdev_wakeup_by_event_get() > WAKEUP_EVENT_NONE) {
-			status = wait_event_timeout(bes2600_cdev.wakeup_reason_wq,
-				bes2600_chrdev_wakeup_by_event_get() ==  WAKEUP_EVENT_NONE, HZ * 2);
-			WARN_ON(status <= 0);
-		}
-		len = sprintf(buf, "wakeup_reason: %u, src_port: %u\n",
-		              bes2600_cdev.wakeup_state, bes2600_cdev.src_port);
-		break;
-	default:
-		len = sprintf(buf, "dpd_calied:%d wifi_opened:%d bt_opened:%d fw_type:%d\n",
-				bes2600_cdev.dpd_calied,
-				bes2600_cdev.wifi_opened,
-				bes2600_cdev.bt_opened,
-				bes2600_cdev.fw_type);
-		break;
-	}
-
-	len = sizeof(buf);
-	/* reset read flag */
-	spin_lock(&bes2600_cdev.status_lock);
-	bes2600_cdev.read_flag = BES_CDEV_READ_NUM_MAX;
-	spin_unlock(&bes2600_cdev.status_lock);
-
-	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
-}
-
-static ssize_t bes2600_chrdev_write(struct file *file,
-		 const char __user *user_buf, size_t count, loff_t *ppos)
-{
-	int i = 0;
-	int cmd_num = ARRAY_SIZE(bes2600_op_map_tab);
-	int cmd_len = 0;
-	int ret = 0;
-	char *info[2] = {0};
-	char *buf = NULL;
-
-	/* copy content from user space to kernel */
-	/* message format:"ifname:wlanx cmd:xxx arg1 arg2 ..." */
-	buf = kmalloc(count + 1, GFP_KERNEL);
-	if (copy_from_user(buf, user_buf, count))
-		return -EFAULT;
-
-	/* add terminal character */
-	buf[count] = '\0';
-
-	/* extract comand and interface */
-	if (bes2600_get_cmd_and_ifname(buf, info) != 0) {
-		bes_err("%s get command fail, the origin string is %s\n", __func__, buf);
-		kfree(buf);
-		return -EINVAL;
-	}
-
-	/* match operation item and execure its handler */
-	cmd_len = strlen(info[1]);
-	for (i = 0; i < cmd_num; i++) {
-		if (cmd_len < bes2600_op_map_tab[i].op_len)
-			continue;
-
-		if (strncasecmp(info[1], bes2600_op_map_tab[i].op, bes2600_op_map_tab[i].op_len) == 0) {
-			ret = bes2600_op_map_tab[i].handler(buf);
-			break;
-		}
-	}
-
-	/* operation item mismatch */
-	if (i == cmd_num) {
-		bes_err("cmd(%s) mismatch\n", info[1]);
-	}
-
-	bes2600_recyle_cmd_and_ifname_mem(info);
-	kfree(buf);
-
-	return (ret == 0) ? count : ret;
-}
-
-static int bes2600_chrdev_release (struct inode *inode, struct file *file)
-{
-	if (atomic_dec_and_test(&bes2600_cdev.num_proc)) {
-		wake_up(&bes2600_cdev.open_wq);
-	}
-
-	bes_devel("bes2600 char device is closed\n");
-
-	return 0;
-}
-
-static struct file_operations bes2600_chardev_fops =
-{
-	.owner = THIS_MODULE,
-	.open = bes2600_chrdev_open,
-	.read = bes2600_chrdev_read,
-	.write = bes2600_chrdev_write,
-	.release = bes2600_chrdev_release,
-};
 
 #ifdef BES2600_WRITE_DPD_TO_FILE
 static int bes2600_chrdev_write_dpd_data_to_file(const char *path, void *buffer, int size)
@@ -1124,12 +672,6 @@ void bes2600_chrdev_update_signal_mode(void)
 
 static void bes2600_chrdev_wifi_force_close_work(struct work_struct *work)
 {
-	char wifi_state[15];
-	char bt_state[15];
-	char fw_type[15];
-	char *env[] = { wifi_state, bt_state, fw_type, NULL };
-	int ret;
-
 	if (bes2600_chrdev_is_wifi_opened()) {
 		bes_devel("system exeception, force wifi down\n");
 
@@ -1146,14 +688,6 @@ static void bes2600_chrdev_wifi_force_close_work(struct work_struct *work)
 			bes2600_chrdev_do_system_close(bes2600_cdev.sbus_ops,
 						bes2600_cdev.sbus_priv);
 		}
-
-		/* notify userspace */
-		snprintf(wifi_state, sizeof(wifi_state), "WIFI_OPENED=%d", bes2600_cdev.wifi_opened);
-		snprintf(bt_state, sizeof(bt_state), "BT_OPENED=%d", bes2600_cdev.bt_opened);
-		snprintf(fw_type, sizeof(fw_type), "FW_TYPE=%d", bes2600_cdev.fw_type);
-		ret = kobject_uevent_env(&bes2600_cdev.device->kobj, KOBJ_CHANGE, env);
-		if (!ret)
-			bes_err("bes2600 notify userspace failed\n");
 	}
 }
 
@@ -1247,46 +781,6 @@ int bes2600_chrdev_wakeup_by_event_get(void)
 
 int bes2600_chrdev_init(struct sbus_ops *ops)
 {
-	int ret = 0;
-
-	/* allocate devide id */
-	ret = alloc_chrdev_region(&bes2600_cdev.dev_id, 0, 1, "bes2600_chrdev");
-	if (ret < 0){
-		bes_err("bes2600 alloc device id fail\n");
-		ret =  -EFAULT;
-		goto fail;
-	}
-
-	/* extract major and minor device id */
-	bes2600_cdev.major = MAJOR(bes2600_cdev.dev_id);
-	bes2600_cdev.minor = MINOR(bes2600_cdev.dev_id);
-
-	/* add char device and bind operation function */
-	bes2600_cdev.cdev.owner = THIS_MODULE;
-	cdev_init(&bes2600_cdev.cdev, &bes2600_chardev_fops);
-	ret = cdev_add(&bes2600_cdev.cdev, bes2600_cdev.dev_id, 1);
-	if (ret < 0){
-		bes_err("bes2600 char device add fail\n");
-		ret =  -EFAULT;
-		goto fail1;
-	}
-
-	/* create class for creating device node */
-	bes2600_cdev.class = class_create("bes2600_chrdev");
-	if (IS_ERR(bes2600_cdev.class)){
-		bes_err("bes2600 char device add fail\n");
-		ret = -EFAULT;
-		goto fail2;
-	}
-
-	/* get char device pointer */
-	bes2600_cdev.device = device_create(bes2600_cdev.class, NULL, bes2600_cdev.dev_id, NULL, "bes2600");
-	if (IS_ERR(bes2600_cdev.device)){
-		bes_err("bes2600 char device create fail\n");
-		ret =  -EFAULT;
-		goto fail3;
-	}
-
 	/* initialise global variable */
 	atomic_set(&bes2600_cdev.num_proc, 0);
 	init_waitqueue_head(&bes2600_cdev.open_wq);
@@ -1318,15 +812,6 @@ int bes2600_chrdev_init(struct sbus_ops *ops)
 	bes_devel("%s done\n", __func__);
 
 	return 0;
-
-fail3:
-	class_destroy(bes2600_cdev.class);
-fail2:
-	cdev_del(&bes2600_cdev.cdev);
-fail1:
-	unregister_chrdev_region(bes2600_cdev.dev_id, 1);
-fail:
-	return ret;
 }
 
 void bes2600_chrdev_free(void)
@@ -1336,9 +821,5 @@ void bes2600_chrdev_free(void)
 	bes2600_free_dpd_log_buffer();
 #endif
 	bes2600_chrdev_free_dpd_data();
-	cdev_del(&bes2600_cdev.cdev);
-	unregister_chrdev_region(bes2600_cdev.dev_id, 1);
-	device_destroy(bes2600_cdev.class, bes2600_cdev.dev_id);
-	class_destroy(bes2600_cdev.class);
 	bes_devel("%s done\n", __func__);
 }