s390utils/s390utils-lcs-revert.patch

From a424411c8dfc944d31c2813d0845f6fa32a4eb36 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=20Hor=C3=A1k?= <dan@danny.cz>
Date: Thu, 18 Jun 2026 09:55:59 +0200
Subject: [PATCH 1/2] Revert "lsznet: Remove support for lcs device type"

This reverts commit 69c89416b0dda98df7ab1651cfa34aab4ead7433.
---
 zconf/lsznet.raw | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/zconf/lsznet.raw b/zconf/lsznet.raw
index fee8636e..5c0e3c22 100755
--- a/zconf/lsznet.raw
+++ b/zconf/lsznet.raw
@@ -35,6 +35,7 @@ readonly -a CU_CARDTYPE=(
 	"CTC adapter"
 	"escon channel"
 	"ficon channel"
+	"LCS OSA"
 	"OSX"
 	"OSM"
 )
@@ -47,6 +48,7 @@ readonly -a CU_DEVNAME=(
 	ctc
 	eth
 	eth
+	eth
 )
 
 readonly -a CU_DEVDRV=(
@@ -55,6 +57,7 @@ readonly -a CU_DEVDRV=(
 	ctcm
 	ctcm
 	ctcm
+	lcs
 	qeth
 	qeth
 )
@@ -65,11 +68,13 @@ readonly -a CU_GROUPCHANNELS=(
 	2
 	2
 	2
+	2
 	3
 	3
 )
 
 readonly -a CHPIDTYPES=(
+	[0x10]=OSE
 	[0x11]=OSD
 	[0x24]=IQD
 	[0x30]=OSX
@@ -84,6 +89,7 @@ readonly -a CU_TCPIP=(
 	3088/08
 	3088/1f
 	3088/1e
+	3088/60
 	1731/02
 	1731/02
 )
-- 
2.54.0


From 763a3ac7e2e3bb3e4ba15026b8fde55f2c0d2c83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=20Hor=C3=A1k?= <dan@danny.cz>
Date: Thu, 18 Jun 2026 09:57:30 +0200
Subject: [PATCH 2/2] Revert "zdev: Remove support for lcs device type"

This reverts commit b6bb87f377bb829e470fb643c18ce732f58cbf51.
---
 zdev/dracut/95zdev-kdump/module-setup.sh |   2 +-
 zdev/dracut/95zdev/module-setup.sh       |   2 +-
 zdev/include/lcs.h                       |  25 ++
 zdev/include/lcs_auto.h                  |  24 ++
 zdev/initramfs/hooks/s390-tools-zdev     |   2 +-
 zdev/man/chzdev.8                        |   2 +-
 zdev/man/lszdev.8                        |   2 +-
 zdev/src/Makefile                        |   6 +
 zdev/src/ctc_auto.c                      |  13 +-
 zdev/src/devtype.c                       |   2 +
 zdev/src/lcs.c                           | 429 +++++++++++++++++++++++
 zdev/src/lcs_auto.c                      | 348 ++++++++++++++++++
 zdev/src/namespace.c                     |   2 +
 13 files changed, 852 insertions(+), 7 deletions(-)
 create mode 100644 zdev/include/lcs.h
 create mode 100644 zdev/include/lcs_auto.h
 create mode 100644 zdev/src/lcs.c
 create mode 100644 zdev/src/lcs_auto.c

diff --git a/zdev/dracut/95zdev-kdump/module-setup.sh b/zdev/dracut/95zdev-kdump/module-setup.sh
index 1052190f..71855bc6 100755
--- a/zdev/dracut/95zdev-kdump/module-setup.sh
+++ b/zdev/dracut/95zdev-kdump/module-setup.sh
@@ -55,7 +55,7 @@ cmdline() {
 installkernel() {
     # Add modules for all device types supported by chzdev (required for
     # auto-configuration)
-    instmods ctcm qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod \
+    instmods ctcm lcs qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod \
              dasd_diag_mod zfcp
 }
 
diff --git a/zdev/dracut/95zdev/module-setup.sh b/zdev/dracut/95zdev/module-setup.sh
index d4ba2ed8..ae5c9811 100644
--- a/zdev/dracut/95zdev/module-setup.sh
+++ b/zdev/dracut/95zdev/module-setup.sh
@@ -61,7 +61,7 @@ installkernel() {
     # Add modules for all device types supported by chzdev (required for
     # auto-configuration)
     hostonly="$(optional_hostonly)" \
-    instmods ctcm qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod \
+    instmods ctcm lcs qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod \
 	     dasd_diag_mod zfcp
 }
 
diff --git a/zdev/include/lcs.h b/zdev/include/lcs.h
new file mode 100644
index 00000000..4b9a01b4
--- /dev/null
+++ b/zdev/include/lcs.h
@@ -0,0 +1,25 @@
+/*
+ * zdev - Modify and display the persistent configuration of devices
+ *
+ * Copyright IBM Corp. 2016, 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef LCS_H
+#define LCS_H
+
+#define	LCS_MOD_NAME		"lcs"
+#define LCS_CCWGROUPDRV_NAME	"lcs"
+#define LCS_CCWDRV_NAME		"lcs"
+#define LCS_ROOTDRV_NAME	"lcs"
+#define	LCS_NUM_DEVS		2
+
+struct devtype;
+struct namespace;
+
+extern struct devtype lcs_devtype;
+extern struct namespace lcs_namespace;
+
+#endif /* LCS_H */
diff --git a/zdev/include/lcs_auto.h b/zdev/include/lcs_auto.h
new file mode 100644
index 00000000..31b9c367
--- /dev/null
+++ b/zdev/include/lcs_auto.h
@@ -0,0 +1,24 @@
+/*
+ * zdev - Modify and display the persistent configuration of devices
+ *
+ * Copyright IBM Corp. 2016, 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef LCS_AUTO_H
+#define LCS_AUTO_H
+
+#include "misc.h"
+
+struct util_list;
+struct ccwgroup_devid;
+struct ccw_devid;
+
+void lcs_auto_add_ids(struct util_list *);
+exit_code_t lcs_auto_get_devid(struct ccwgroup_devid *, struct ccw_devid *,
+			       err_t);
+exit_code_t lcs_auto_is_possible(struct ccwgroup_devid *, err_t);
+
+#endif /* LCS_AUTO_H */
diff --git a/zdev/initramfs/hooks/s390-tools-zdev b/zdev/initramfs/hooks/s390-tools-zdev
index 9ac5a6b6..06351995 100644
--- a/zdev/initramfs/hooks/s390-tools-zdev
+++ b/zdev/initramfs/hooks/s390-tools-zdev
@@ -29,7 +29,7 @@ esac
 
 # Add modules for all device types supported by chzdev (required for
 # auto-configuration)
-zdev_modules="qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod dasd_diag_mod zfcp"
+zdev_modules="lcs qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod dasd_diag_mod zfcp"
 
 for x in $zdev_modules ; do
 	manual_add_modules ${x}
diff --git a/zdev/man/chzdev.8 b/zdev/man/chzdev.8
index 6e402719..91dddc35 100644
--- a/zdev/man/chzdev.8
+++ b/zdev/man/chzdev.8
@@ -61,7 +61,7 @@ chzdev - Configure z Systems specific devices
 .B chzdev
 is a tool for configuring devices and device drivers which are specific to the
 IBM z Systems platform. Supported device types include storage devices (DASD
-and zFCP) and networking devices (QETH and CTC).
+and zFCP) and networking devices (QETH, CTC and LCS).
 .PP
 .
 .SS "Configurations"
diff --git a/zdev/man/lszdev.8 b/zdev/man/lszdev.8
index 03b80c30..3aa1b941 100644
--- a/zdev/man/lszdev.8
+++ b/zdev/man/lszdev.8
@@ -60,7 +60,7 @@ lszdev - Display configuration of z Systems specific devices
 .B lszdev
 displays the configuration of devices and device drivers that
 are specific to IBM z Systems. Supported device types include
-storage devices (DASD and zFCP) and networking devices (QETH and CTC).
+storage devices (DASD and zFCP) and networking devices (QETH, CTC and LCS).
 .PP
 .
 .PP
diff --git a/zdev/src/Makefile b/zdev/src/Makefile
index 57e28015..07943073 100644
--- a/zdev/src/Makefile
+++ b/zdev/src/Makefile
@@ -36,6 +36,9 @@ chzdev_objects += nic.o qeth.o qeth_auto.o
 # CTC devtype
 chzdev_objects += ctc.o ctc_auto.o
 
+# LCS devtype
+chzdev_objects += lcs.o lcs_auto.o
+
 # AP devtype
 chzdev_objects += ap.o
 
@@ -69,6 +72,9 @@ lszdev_objects += nic.o qeth.o qeth_auto.o
 # CTC devtype
 lszdev_objects += ctc.o ctc_auto.o
 
+# LCS devtype
+lszdev_objects += lcs.o lcs_auto.o
+
 # AP devtype
 lszdev_objects += ap.o
 
diff --git a/zdev/src/ctc_auto.c b/zdev/src/ctc_auto.c
index 11c0a5e0..e2b7701b 100644
--- a/zdev/src/ctc_auto.c
+++ b/zdev/src/ctc_auto.c
@@ -15,6 +15,7 @@
 #include "ccwgroup.h"
 #include "ctc.h"
 #include "ctc_auto.h"
+#include "lcs.h"
 #include "module.h"
 #include "path.h"
 
@@ -38,7 +39,9 @@ static struct cutype ctc_cutypes[] = {
  * 1. A CTC device can be grouped from 2 CCW devices
  *    a) Read device
  *    b) Write device
- * 2. All CCW devices must be bound to the CTC CCW device driver.
+ * 2. All CCW devices must be bound to the CTC CCW device driver. Note that
+ *    due to an overlap in CU-Types, CCW device could also be bound to
+ *    the LCS device driver.
  * 3. The subchannel of all CCW devices must be defined with the same CHPID
  * 4. None of the CCW devices is part of an existing CCWGROUP device
  */
@@ -110,7 +113,7 @@ static exit_code_t add_cb(const char *path, const char *filename, void *data)
 }
 
 /* Return a sorted ptrlist of struct ccw_devinfos for all CCW devices
- * bound to the ctc CCW device driver with matching CUTYPE.
+ * bound to the ctc or lcs CCW device driver with matching CUTYPE.
  * The result must be freed using ptrlist_free(,1); */
 static struct util_list *read_sorted_ctc_devinfos(void)
 {
@@ -127,6 +130,12 @@ static struct util_list *read_sorted_ctc_devinfos(void)
 		path_for_each(path, add_cb, infos);
 	free(path);
 
+	/* Add CCW devices bound to the LCS CCW device driver. */
+	path = path_get_sys_bus_drv(CCW_BUS_NAME, LCS_CCWDRV_NAME);
+	if (util_path_is_dir(path))
+		path_for_each(path, add_cb, infos);
+	free(path);
+
 	/* For each CHPID: Find groups. Add to result list. */
 	util_list_sort(infos, info_cmp, NULL);
 
diff --git a/zdev/src/devtype.c b/zdev/src/devtype.c
index fd34bb5a..3085fdd6 100644
--- a/zdev/src/devtype.c
+++ b/zdev/src/devtype.c
@@ -18,6 +18,7 @@
 #include "devnode.h"
 #include "devtype.h"
 #include "generic_ccw.h"
+#include "lcs.h"
 #include "misc.h"
 #include "module.h"
 #include "namespace.h"
@@ -35,6 +36,7 @@ struct devtype *devtypes[] = {
 	&zfcp_devtype,
 	&qeth_devtype,
 	&ctc_devtype,
+	&lcs_devtype,
 	&ap_devtype,
 	&virtio_devtype,
 	&generic_ccw_devtype,	/* Generic types should come last. */
diff --git a/zdev/src/lcs.c b/zdev/src/lcs.c
new file mode 100644
index 00000000..861d030d
--- /dev/null
+++ b/zdev/src/lcs.c
@@ -0,0 +1,429 @@
+/*
+ * zdev - Modify and display the persistent configuration of devices
+ *
+ * Copyright IBM Corp. 2016, 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "attrib.h"
+#include "ccw.h"
+#include "ccwgroup.h"
+#include "device.h"
+#include "devtype.h"
+#include "internal.h"
+#include "lcs.h"
+#include "lcs_auto.h"
+#include "misc.h"
+#include "namespace.h"
+#include "setting.h"
+
+#define DEVNAME	"LCS device"
+
+/*
+ * LCS device ID namespace methods.
+ */
+static exit_code_t lcs_parse_devid(struct ccwgroup_devid *devid_ptr,
+				   const char *id, err_t err)
+{
+	struct ccwgroup_devid devid;
+	const char *reason = NULL;
+	exit_code_t rc;
+
+	rc = ccwgroup_parse_devid(&devid, id, err);
+	if (rc)
+		return rc;
+
+	if (devid.num > LCS_NUM_DEVS) {
+		reason = "Too many CCW device IDs specified";
+		rc = EXIT_INVALID_ID;
+	} else if (devid_ptr)
+		*devid_ptr = devid;
+
+	if (reason) {
+		err_t_print(err, "Error in %s ID format: %s: %s\n", DEVNAME,
+			    reason, id);
+	}
+
+	return rc;
+}
+
+static exit_code_t lcs_parse_devid_range(struct ccwgroup_devid *from_ptr,
+					 struct ccwgroup_devid *to_ptr,
+					 const char *range, err_t err)
+{
+	char *from_str, *to_str;
+	struct ccwgroup_devid from, to;
+	exit_code_t rc;
+	const char *reason = NULL;
+
+	/* Split range. */
+	from_str = misc_strdup(range);
+	to_str = strchr(from_str, '-');
+	if (!to_str) {
+		rc = EXIT_INVALID_ID;
+		reason = "Missing hyphen";
+		goto out;
+	}
+	*to_str = 0;
+	to_str++;
+
+	/* Parse range start end end ID. */
+	rc = lcs_parse_devid(&from, from_str, err);
+	if (rc)
+		goto out;
+
+	rc = lcs_parse_devid(&to, to_str, err);
+	if (rc)
+		goto out;
+
+	/* Only allow ranges on CCWGROUP devices specified as single ID. */
+	if (from.num != 1 || to.num != 1) {
+		rc = EXIT_INVALID_ID;
+		reason = "Ranges only supported on single CCW device IDs";
+		goto out;
+	}
+
+	rc = EXIT_OK;
+	if (from_ptr)
+		*from_ptr = from;
+	if (to_ptr)
+		*to_ptr = to;
+
+out:
+	free(from_str);
+
+	if (reason) {
+		err_t_print(err, "Error in %s ID range format: %s: %s\n",
+			    DEVNAME, reason, range);
+	}
+
+	return rc;
+}
+
+static bool lcs_parse_devid_range_simple(struct ccwgroup_devid *from,
+					 struct ccwgroup_devid *to,
+					 const char *range)
+{
+	if (lcs_parse_devid_range(from, to, range, err_ignore) == EXIT_OK)
+		return true;
+
+	return false;
+}
+
+static exit_code_t lcs_ns_is_id_valid(const char *id, err_t err)
+{
+	return lcs_parse_devid(NULL, id, err);
+}
+
+static char *lcs_ns_normalize_id(const char *id)
+{
+	struct ccwgroup_devid devid;
+
+	if (lcs_parse_devid(&devid, id, err_ignore) != EXIT_OK)
+		return NULL;
+
+	return ccwgroup_devid_to_str(&devid);
+}
+
+static void *lcs_ns_parse_id(const char *id, err_t err)
+{
+	struct ccwgroup_devid *devid;
+
+	devid = misc_malloc(sizeof(struct ccwgroup_devid));
+	if (lcs_parse_devid(devid, id, err) != EXIT_OK) {
+		free(devid);
+		return NULL;
+	}
+
+	return devid;
+}
+
+static exit_code_t lcs_ns_is_id_range_valid(const char *range, err_t err)
+{
+	return lcs_parse_devid_range(NULL, NULL, range, err);
+}
+
+static unsigned long lcs_ns_num_ids_in_range(const char *range)
+{
+	struct ccwgroup_devid f, t;
+
+	if (!lcs_parse_devid_range_simple(&f, &t, range))
+		return 0;
+
+	if (f.devid[0].cssid != t.devid[0].cssid ||
+	    f.devid[0].ssid != t.devid[0].ssid)
+		return 0;
+
+	if (f.devid[0].devno > t.devid[0].devno)
+		return 0;
+
+	return t.devid[0].devno - f.devid[0].devno + 1;
+}
+
+static void lcs_ns_range_start(struct ns_range_iterator *it, const char *range)
+{
+	struct ccwgroup_devid from, to;
+
+	if (!lcs_parse_devid_range_simple(&from, &to, range)) {
+		memset(it, 0, sizeof(struct ns_range_iterator));
+		return;
+	}
+
+	it->devid = ccwgroup_copy_devid(&from);
+	it->devid_last = ccwgroup_copy_devid(&to);
+	it->id = ccwgroup_devid_to_str(it->devid);
+}
+
+static bool lcs_ns_is_id_blacklisted(const char *id)
+{
+	struct ccwgroup_devid devid;
+	char *ccw_id;
+	unsigned int i;
+	bool result = false;
+
+	if (lcs_parse_devid(&devid, id, err_ignore) != EXIT_OK)
+		return false;
+	for (i = 0; i < devid.num; i++) {
+		ccw_id = ccw_devid_to_str(&devid.devid[i]);
+		result = ccw_is_id_blacklisted(ccw_id);
+		free(ccw_id);
+		if (result)
+			break;
+	}
+
+	return result;
+}
+
+static void lcs_ns_unblacklist_id(const char *id)
+{
+	struct ccwgroup_devid devid;
+	char *ccw_id;
+	unsigned int i;
+
+	if (lcs_parse_devid(&devid, id, err_ignore) != EXIT_OK)
+		return;
+	for (i = 0; i < devid.num; i++) {
+		ccw_id = ccw_devid_to_str(&devid.devid[i]);
+		if (ccw_is_id_blacklisted(ccw_id))
+			ccw_unblacklist_id(ccw_id);
+		free(ccw_id);
+	}
+}
+
+/*
+ * LCS device ID namespace.
+ */
+
+struct namespace lcs_namespace = {
+	.devname		= DEVNAME,
+	.is_id_valid		= lcs_ns_is_id_valid,
+	.is_id_similar		= ccwgroup_is_id_similar,
+	.cmp_ids		= ccwgroup_cmp_ids,
+	.normalize_id		= lcs_ns_normalize_id,
+	.parse_id		= lcs_ns_parse_id,
+	.cmp_parsed_ids		= ccwgroup_cmp_parsed_ids,
+	.qsort_cmp		= ccwgroup_qsort_cmp,
+	.is_id_range_valid	= lcs_ns_is_id_range_valid,
+	.num_ids_in_range	= lcs_ns_num_ids_in_range,
+	.is_id_in_range		= ccwgroup_is_id_in_range,
+	.range_start		= lcs_ns_range_start,
+	.range_next		= ccwgroup_range_next,
+
+	/* Blacklist handling. */
+	.is_blacklist_active	= ccw_is_blacklist_active,
+	.is_id_blacklisted	= lcs_ns_is_id_blacklisted,
+	.is_id_range_blacklisted = ccw_is_id_range_blacklisted,
+	.unblacklist_id		= lcs_ns_unblacklist_id,
+	.unblacklist_id_range	= ccw_unblacklist_id_range,
+	.blacklist_persist	= ccw_blacklist_persist,
+};
+
+/*
+ * LCS device attributes.
+ */
+
+static struct attrib lcs_attr_lancmd_timeout = {
+	.name = "lancmd_timeout",
+	.title = "Modify LAN command timeout",
+	.desc =
+	"Specify the time in seconds that the LCS driver waits for a reply\n"
+	"after issuing a LAN command to the LAN adapter.\n",
+	.defval = "5",
+	.accept = ACCEPT_ARRAY(ACCEPT_NUM_GE(1)),
+};
+
+static struct attrib lcs_attr_recover = {
+	.name = "recover",
+	.title = "Trigger device recovery",
+	.desc =
+	"Write '1' to this attribute to restart the recovery process for the\n"
+	"QETH device.\n",
+	.accept = ACCEPT_ARRAY(ACCEPT_NUM(1)),
+	.writeonly = 1,
+	.activeonly = 1,
+};
+
+/*
+ * LCS subtype methods.
+ */
+
+static exit_code_t lcs_st_is_definable(struct subtype *st, const char *id,
+				       err_t err)
+{
+	struct ccwgroup_subtype_data *data = st->data;
+	struct ccwgroup_devid devid;
+	exit_code_t rc;
+
+	rc = ccwgroup_parse_devid(&devid, id, err);
+	if (rc)
+		return rc;
+
+	if (subtype_device_exists_active(st, id))
+		return EXIT_OK;
+
+	if (devid.num == data->num_devs)
+		return lcs_auto_is_possible(&devid, err);
+
+	if (devid.num == 1)
+		return lcs_auto_get_devid(NULL, &devid.devid[0], err);
+
+	err_t_print(err, "Invalid number of CCW device IDs\n");
+
+	return EXIT_INVALID_ID;
+}
+
+/**
+ * device_detect_definable - Detect configuration of definable device
+ * @st: Device subtype
+ * @dev: Device
+ *
+ * Detect the full ID and default parameters for non-existing but definable
+ * device @dev and update active.definable. Return %EXIT_OK on success, or an
+ * error code otherwise.
+ */
+static exit_code_t lcs_st_detect_definable(struct subtype *st,
+					   struct device *dev)
+{
+	struct ccwgroup_devid *devid;
+	exit_code_t rc;
+
+	devid = dev->devid;
+	if (devid->num == 1) {
+		/* Detect possible group for this device. */
+		rc = lcs_auto_get_devid(devid, &devid->devid[0],
+					err_delayed_print);
+		if (rc) {
+			error("Auto-detection failed for %s %s\n"
+			      "Please be sure to specify full CCWGROUP ID!\n",
+			      st->devname, dev->id);
+			return rc;
+		}
+		free(dev->id);
+		dev->id = ccwgroup_devid_to_str(dev->devid);
+	}
+
+	dev->active.definable = 1;
+
+	return EXIT_OK;
+}
+
+static void lcs_st_add_definable_ids(struct subtype *st, struct util_list *ids)
+{
+	lcs_auto_add_ids(ids);
+}
+
+/*
+ * LCS subtype.
+ */
+
+static struct ccwgroup_subtype_data lcs_data = {
+	.ccwgroupdrv	= LCS_CCWGROUPDRV_NAME,
+	.ccwdrv		= LCS_CCWDRV_NAME,
+	.rootdrv	= LCS_ROOTDRV_NAME,
+	.mod		= LCS_MOD_NAME,
+	.num_devs	= LCS_NUM_DEVS,
+};
+
+static struct subtype lcs_subtype = {
+	.super		= &ccwgroup_subtype,
+	.devtype	= &lcs_devtype,
+	.name		= "lcs",
+	.title		= "LAN-Channel-Station (LCS) network devices",
+	.devname	= DEVNAME,
+	.modules	= STRING_ARRAY(LCS_MOD_NAME),
+	.namespace	= &lcs_namespace,
+	.data		= &lcs_data,
+
+	.dev_attribs = ATTRIB_ARRAY(
+		&ccw_attr_online,
+		&lcs_attr_lancmd_timeout,
+		&lcs_attr_recover,
+		&internal_attr_early,
+	),
+	.unknown_dev_attribs	= 1,
+	.support_definable	= 1,
+
+	.is_definable		= &lcs_st_is_definable,
+	.detect_definable	= &lcs_st_detect_definable,
+	.add_definable_ids	= &lcs_st_add_definable_ids,
+};
+
+/*
+ * LCS devtype methods.
+ */
+
+/* Clean up all resources used by devtype object. */
+static void lcs_devtype_exit(struct devtype *dt)
+{
+	setting_list_free(dt->active_settings);
+	setting_list_free(dt->persistent_settings);
+}
+
+static exit_code_t lcs_devtype_read_settings(struct devtype *dt,
+					     config_t config)
+{
+	/* No kernel or module parameters exist for the lcs device driver,
+	 * but at least determine module loaded state. */
+	dt->active_settings = setting_list_new();
+	dt->persistent_settings = setting_list_new();
+
+	if (SCOPE_ACTIVE(config))
+		dt->active_exists = devtype_is_module_loaded(dt);
+
+	return EXIT_OK;
+}
+
+static exit_code_t lcs_devtype_write_settings(struct devtype *dt,
+					      config_t config)
+{
+	/* No kernel or module parameters exist for the lcs device driver. */
+
+	return EXIT_OK;
+}
+
+/*
+ * LCS devtype.
+ */
+
+struct devtype lcs_devtype = {
+	.name		= "lcs",
+	.title		= "", /* Only use subtypes. */
+	.devname	= "LCS",
+
+	.subtypes = SUBTYPE_ARRAY(
+		&lcs_subtype,
+	),
+
+	.type_attribs = ATTRIB_ARRAY(
+	),
+
+	.exit			= &lcs_devtype_exit,
+
+	.read_settings		= &lcs_devtype_read_settings,
+	.write_settings		= &lcs_devtype_write_settings,
+};
diff --git a/zdev/src/lcs_auto.c b/zdev/src/lcs_auto.c
new file mode 100644
index 00000000..848897cb
--- /dev/null
+++ b/zdev/src/lcs_auto.c
@@ -0,0 +1,348 @@
+/*
+ * zdev - Modify and display the persistent configuration of devices
+ *
+ * Copyright IBM Corp. 2016, 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <string.h>
+
+#include "lib/util_path.h"
+
+#include "ccw.h"
+#include "ccwgroup.h"
+#include "ctc.h"
+#include "lcs.h"
+#include "lcs_auto.h"
+#include "module.h"
+#include "path.h"
+
+struct cutype {
+	unsigned int cutype:16;
+	unsigned int cumodel:8;
+};
+
+static struct cutype lcs_cutypes[] = {
+	{ .cutype = 0x3088, .cumodel = 0x08, },
+	{ .cutype = 0x3088, .cumodel = 0x1f, },
+	{ .cutype = 0x3088, .cumodel = 0x60, },
+};
+
+/*
+ * LCS autodetection
+ *
+ * A LCS device must be grouped before it can be used. The following
+ * rules apply to grouping:
+ *
+ * 1. A LCS device can be grouped from 2 CCW devices
+ *    a) Read device
+ *    b) Write device
+ * 2. All CCW devices must be bound to the LCS CCW device driver. Note that
+ *    due to an overlap in CU-Types, CCW device could also be bound to
+ *    the LCS device driver.
+ * 3. The subchannel of all CCW devices must be defined with the same CHPID
+ * 4. None of the CCW devices is part of an existing CCWGROUP device
+ */
+
+/* Compare by: 1. CHPID, 2. CUTYPE, 3. DEVTYPE, 4. CCW device ID
+ * -1 = a < b    1 = a > b    0 = a == b. */
+static int info_cmp(void *a, void *b, void *data)
+{
+	struct ptrlist_node *pa = a, *pb = b;
+	struct ccw_devinfo *ia = pa->ptr, *ib = pb->ptr;
+	int r;
+
+	r = ccw_devinfo_chpids_cmp(ia, ib);
+	if (r)
+		return r;
+
+	r = ccw_devinfo_cutype_cmp(ia, ib);
+	if (r)
+		return r;
+
+	r = ccw_devinfo_devtype_cmp(ia, ib);
+	if (r)
+		return r;
+
+	return ccw_cmp_devids(&ia->devid, &ib->devid);
+}
+
+static bool is_compatible(struct ccw_devinfo *a, struct ccw_devinfo *b)
+{
+	if (ccw_devinfo_chpids_cmp(a, b) == 0 &&
+	    ccw_devinfo_cutype_cmp(a, b) == 0 &&
+	    ccw_devinfo_devtype_cmp(a, b) == 0)
+		return true;
+
+	return false;
+}
+
+static bool is_lcs(struct ccw_devinfo *info)
+{
+	unsigned int i;
+
+	/* Rule out devices which can be confirmed to be CTC devices. */
+	if (ctc_confirm(&info->devid))
+		return false;
+
+	for (i = 0; i < ARRAY_SIZE(lcs_cutypes); i++) {
+		if (info->cutype == lcs_cutypes[i].cutype &&
+		    info->cumodel == lcs_cutypes[i].cumodel)
+			return true;
+	}
+
+	return false;
+}
+
+/* Add device info for all LCS CCW devices to ptrlist in data. */
+static exit_code_t add_cb(const char *path, const char *filename, void *data)
+{
+	struct ccw_devid devid;
+	struct util_list *infos = data;
+	struct ccw_devinfo *devinfo;
+
+	if (!strchr(filename, '.'))
+		return EXIT_OK;
+	if (!ccw_parse_devid_simple(&devid, filename))
+		return EXIT_OK;
+	devinfo = ccw_devinfo_get(&devid, 0);
+	if (devinfo->exists && is_lcs(devinfo))
+		ptrlist_add(infos, devinfo);
+	else
+		free(devinfo);
+
+	return EXIT_OK;
+}
+
+/* Return a sorted ptrlist of struct ccw_devinfos for all CCW devices
+ * bound to the lcs or ctc CCW device driver with matching CUTYPE.
+ * The result must be freed using ptrlist_free(,1); */
+static struct util_list *read_sorted_lcs_devinfos(void)
+{
+	struct util_list *infos;
+	char *path;
+
+	/* Get CHPID information for all devices handled by the LCS driver. */
+	infos = ptrlist_new();
+
+	/* Add CCW devices bound to the LCS CCW device driver. */
+	module_try_load_once(LCS_MOD_NAME, NULL);
+	path = path_get_sys_bus_drv(CCW_BUS_NAME, LCS_CCWDRV_NAME);
+	if (util_path_is_dir(path))
+		path_for_each(path, add_cb, infos);
+	free(path);
+
+	/* Add CCW devices bound to the CTC CCW device driver. */
+	path = path_get_sys_bus_drv(CCW_BUS_NAME, CTC_CCWDRV_NAME);
+	if (util_path_is_dir(path))
+		path_for_each(path, add_cb, infos);
+	free(path);
+
+	/* For each CHPID: Find groups. Add to result list. */
+	util_list_sort(infos, info_cmp, NULL);
+
+	return infos;
+}
+
+static void add_ccwgroup_devid(struct util_list *devids, struct ccw_devid *read,
+			       struct ccw_devid *write)
+{
+	struct ccwgroup_devid devid;
+
+	devid.devid[0] = *read;
+	devid.devid[1] = *write;
+	devid.num = LCS_NUM_DEVS;
+
+	ptrlist_add(devids, ccwgroup_copy_devid(&devid));
+}
+
+static void add_groupable_devids(struct util_list *devids,
+				 struct util_list *infos)
+{
+	struct ptrlist_node *curr, *next;
+	struct ccw_devinfo *r, *w;
+
+	/* For each CHPID: Find groups. Add to result list. */
+	curr = util_list_start(infos);
+	while (curr) {
+		next = util_list_next(infos, curr);
+		if (!next)
+			break;
+		r = curr->ptr;
+		w = next->ptr;
+		if (is_compatible(r, w) && EVEN(r->devid.devno) &&
+		    ccw_devid_distance(&r->devid, &w->devid) == 1) {
+			add_ccwgroup_devid(devids, &r->devid, &w->devid);
+			curr = util_list_next(infos, next);
+		} else
+			curr = next;
+	}
+}
+
+/* Add CCWGROUP IDs of lcs devices that can be grouped to strlist @ids. */
+void lcs_auto_add_ids(struct util_list *ids)
+{
+	struct util_list *infos, *devids;
+	struct ptrlist_node *p;
+	char *id;
+
+	infos = read_sorted_lcs_devinfos();
+	devids = ptrlist_new();
+	add_groupable_devids(devids, infos);
+
+	util_list_iterate(devids, p) {
+		id = ccwgroup_devid_to_str(p->ptr);
+		strlist_add(ids, id);
+		free(id);
+	}
+
+	ptrlist_free(devids, 1);
+	ptrlist_free(infos, 1);
+}
+
+exit_code_t lcs_auto_get_devid(struct ccwgroup_devid *devid_ptr,
+			       struct ccw_devid *ccw_devid, err_t err)
+{
+	struct util_list *devids, *infos;
+	struct ptrlist_node *p, *read, *write;
+	struct ccw_devinfo *r, *w;
+	struct ccwgroup_devid *devid;
+	exit_code_t rc;
+
+	infos = read_sorted_lcs_devinfos();
+
+	/* Try to find an ID from the canonical auto-generated list. */
+	devids = ptrlist_new();
+	add_groupable_devids(devids, infos);
+
+	util_list_iterate(devids, p) {
+		devid = p->ptr;
+		if (ccw_cmp_devids(ccw_devid, &devid->devid[0]) != 0)
+			continue;
+		rc = EXIT_OK;
+		if (devid_ptr)
+			*devid_ptr = *devid;
+		goto out;
+	}
+
+	/* Try to create a CCWGROUP ID with the specified ID as read device. */
+
+	/* Get CCW device info for read device. */
+	read = NULL;
+	util_list_iterate(infos, read) {
+		r = read->ptr;
+		if (ccw_cmp_devids(&r->devid, ccw_devid) == 0)
+			break;
+	}
+	if (!read) {
+		err_t_print(err, "Read CCW device not found\n");
+		rc = EXIT_GROUP_NOT_FOUND;
+		goto out;
+	}
+	if (!EVEN(r->devid.devno)) {
+		err_t_print(err, "Read CCW device number not even\n");
+		rc = EXIT_GROUP_INVALID;
+		goto out;
+	}
+
+	/* Get CCW device ID for write device. */
+	write = util_list_next(infos, read);
+	if (!write) {
+		err_t_print(err, "Write CCW device not found\n");
+		rc = EXIT_GROUP_NOT_FOUND;
+		goto out;
+	}
+	w = write->ptr;
+	if (!is_compatible(r, w)) {
+		err_t_print(err, "No compatible write CCW device found\n");
+		rc = EXIT_GROUP_INVALID;
+		goto out;
+	}
+	if (ccw_devid_distance(&r->devid, &w->devid) != 1) {
+		err_t_print(err, "Write CCW device ID must be read plus one\n");
+		rc = EXIT_GROUP_INVALID;
+		goto out;
+	}
+
+	rc = EXIT_OK;
+	if (devid_ptr) {
+		devid_ptr->devid[0] = r->devid;
+		devid_ptr->devid[1] = w->devid;
+		devid_ptr->num = LCS_NUM_DEVS;
+	}
+
+out:
+	ptrlist_free(devids, 1);
+	ptrlist_free(infos, 1);
+
+	return rc;
+}
+
+exit_code_t lcs_auto_is_possible(struct ccwgroup_devid *devid, err_t err)
+{
+	struct ccw_devinfo *info[LCS_NUM_DEVS];
+	unsigned int i;
+	char *ccwid;
+	const char *msg;
+	exit_code_t rc;
+
+	if (devid->num < LCS_NUM_DEVS) {
+		err_t_print(err, "Not enough CCW device IDs in LCS device "
+			    "ID\n");
+		return EXIT_INCOMPLETE_ID;
+	}
+	if (devid->num > LCS_NUM_DEVS) {
+		err_t_print(err, "LCS device ID contains too many CCW device "
+			    "IDs\n");
+		return EXIT_INVALID_ID;
+	}
+	if (ccw_devid_distance(&devid->devid[0], &devid->devid[1]) != 1) {
+		err_t_print(err, "Write device ID must be read plus one\n");
+		return EXIT_GROUP_INVALID;
+	}
+	if (!EVEN(devid->devid[0].devno)) {
+		err_t_print(err, "Device number of read device ID must be "
+			    "even\n");
+		return EXIT_GROUP_INVALID;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(info); i++)
+		info[i] = ccw_devinfo_get(&devid->devid[i], 1);
+
+	rc = EXIT_OK;
+	msg = NULL;
+	for (i = 0; i < ARRAY_SIZE(info); i++) {
+		if (!info[i]->exists) {
+			msg = "CCW device %s does not exist\n";
+			rc = EXIT_GROUP_NOT_FOUND;
+		} else if (info[i]->grouped) {
+			msg = "CCW device %s already grouped\n";
+			rc = EXIT_GROUP_ALREADY;
+		} else if (i > 0 &&
+			   ccw_devinfo_chpids_cmp(info[i - 1], info[i]) != 0) {
+			msg = "CCW device %s is not on the same CHPID\n";
+			rc = EXIT_GROUP_INVALID;
+		} else if (i > 0 &&
+			   ccw_devinfo_cutype_cmp(info[i - 1], info[i]) != 0) {
+			msg = "CUTYPE of CCW device %s differs\n";
+			rc = EXIT_GROUP_INVALID;
+		} else if (i > 0 &&
+			   ccw_devinfo_devtype_cmp(info[i - 1], info[i]) != 0) {
+			msg = "DEVTYPE of CCW device %s differs\n";
+			rc = EXIT_GROUP_INVALID;
+		}
+		if (!msg)
+			continue;
+		ccwid = ccw_devid_to_str(&devid->devid[i]);
+		err_t_print(err, msg, ccwid);
+		free(ccwid);
+		break;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(info); i++)
+		free(info[i]);
+
+	return rc;
+}
diff --git a/zdev/src/namespace.c b/zdev/src/namespace.c
index b4c3d754..f0ed3c97 100644
--- a/zdev/src/namespace.c
+++ b/zdev/src/namespace.c
@@ -13,6 +13,7 @@
 #include "ccw.h"
 #include "ctc.h"
 #include "devtype.h"
+#include "lcs.h"
 #include "namespace.h"
 #include "qeth.h"
 #include "zfcp_lun.h"
@@ -23,6 +24,7 @@ struct namespace *namespaces[] = {
 	&zfcp_lun_namespace,
 	&qeth_namespace,
 	&ctc_namespace,
+	&lcs_namespace,
 	&ap_namespace,
 	NULL,
 };
-- 
2.54.0