Merge tag 'gpio-updates-for-v6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "We have three new drivers, some refactoring in the GPIO core, lots of
  various changes across many drivers, new configfs interface for the
  virtual gpio-aggregator module and DT-bindings updates.

  The treewide conversion of GPIO drivers to using the new value setter
  callbacks is ongoing with another round of GPIO drivers updated. You
  will also see these commits coming in from other subsystems as with
  the relevant changes merged into mainline last cycle, I've started
  converting GPIO providers located elsewhere than drivers/gpio/.

  GPIO core:
   - use more lock guards where applicable
   - refactor GPIO ACPI code and shrink it in the process by 8%
   - move GPIO ACPI quirks into a separate file
   - remove unneeded #ifdef
   - convert GPIO devres helpers to using devm_add_action() where
     applicable which shrinks and simplifies the code
   - refactor GPIO descriptor validation in GPIO consumer interfaces
   - don't allow setting values on input lines in the GPIO core which
     will take off the burden from GPIO drivers of checking this down
     the line
   - provide gpiod_is_equal() as a way of safely comparing two GPIO
     descriptors (the only current user is in regulator core)

  New drivers:
   - add the GPIO module for the max77759 multifunction device
   - add the GPIO driver for the VeriSilicon BLZP1600 GPIO controller
   - add the GPIO driver for the Spacemit K1 SoC

  Driver improvements:
   - convert more drivers to using the new GPIO line value setter
     callbacks
   - convert more drivers to making the irq_chip immutable as is
     recommended by the interrupt subsystem
   - extend build testing coverage by enabling more modules to be built
     with COMPILE_TEST=y
   - extend the gpio-aggregator module with a configfs interface that
     makes the setup easier for user-space than the existing
     driver-level sysfs attributes and also adds more advanced
     configuration features (such as referring to aggregated lines by
     their original names or modifying their names as exposed by the
     aggregated chip)
   - add a missing mutex_destroy() in gpio-imx-scu
   - add an OF polarity quirk for s5m8767
   - allow building gpio-vf610 as a loadable module
   - make gpio-mxc not hardcode its GPIO base number with GPIO SYSFS
     interface disabled (another small step towards getting rid of the
     global GPIO numberspace)
   - add support for level-triggered interrupts to gpio-pca953x
   - don't double-check the ngpios property in gpio-ds4520 as GPIO core
     already does it
   - don't double-check the number of GPIOs in gpio-imx-scu as GPIO core
     already does it
   - remove unused callbacks from gpio-max3191x

  DT bindings:
   - add device-tree bindings for max77759, spacemit,k1 and blzp1600
     (new drivers added this cycle)
   - document more properties for gpio-vf610 and gpio-tegra186
   - document a new pca95xx variant
   - fix style of examples in several GPIO DT-binding documents

  Misc:
   - TODO list updates"

* tag 'gpio-updates-for-v6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (123 commits)
  gpio: timberdale: select GPIOLIB_IRQCHIP
  gpio: lpc18xx: select GPIOLIB_IRQCHIP
  gpio: grgpio: select GPIOLIB_IRQCHIP
  gpio: bcm-kona: select GPIOLIB_IRQCHIP
  dt-bindings: gpio: vf610: add ngpios and gpio-reserved-ranges
  gpio: davinci: select GPIOLIB_IRQCHIP
  gpiolib-acpi: Update file references in the Documentation and MAINTAINERS
  gpiolib: acpi: Move quirks to a separate file
  gpiolib: acpi: Add acpi_gpio_need_run_edge_events_on_boot() getter
  gpiolib: acpi: Handle deferred list via new API
  gpiolib: acpi: Make sure we fill struct acpi_gpio_info
  gpiolib: acpi: Switch to use enum in acpi_gpio_in_ignore_list()
  gpiolib: acpi: Use temporary variable for struct acpi_gpio_info
  gpiolib: remove unneeded #ifdef
  gpio: mpc8xxx: select GPIOLIB_IRQCHIP
  gpio: pxa: select GPIOLIB_IRQCHIP
  gpio: pxa: Make irq_chip immutable
  gpio: timberdale: Make irq_chip immutable
  gpio: xgene-sb: Make irq_chip immutable
  gpio: davinci: Make irq_chip immutable
  ...

1 files changed, 939 insertions, 165 deletions

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index d232ea865356..6f941db02c04 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -9,10 +9,13 @@
 
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
+#include <linux/configfs.h>
 #include <linux/ctype.h>
 #include <linux/delay.h>
 #include <linux/idr.h>
 #include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/lockdep.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -27,226 +30,200 @@
 #include <linux/gpio/driver.h>
 #include <linux/gpio/machine.h>
 
+#include "dev-sync-probe.h"
+
 #define AGGREGATOR_MAX_GPIOS 512
+#define AGGREGATOR_LEGACY_PREFIX "_sysfs"
 
 /*
  * GPIO Aggregator sysfs interface
  */
 
 struct gpio_aggregator {
+	struct dev_sync_probe_data probe_data;
+	struct config_group group;
 	struct gpiod_lookup_table *lookups;
-	struct platform_device *pdev;
+	struct mutex lock;
+	int id;
+
+	/* List of gpio_aggregator_line. Always added in order */
+	struct list_head list_head;
+
+	/* used by legacy sysfs interface only */
+	bool init_via_sysfs;
 	char args[];
 };
 
+struct gpio_aggregator_line {
+	struct config_group group;
+	struct gpio_aggregator *parent;
+	struct list_head entry;
+
+	/* Line index within the aggregator device */
+	unsigned int idx;
+
+	/* Custom name for the virtual line */
+	const char *name;
+	/* GPIO chip label or line name */
+	const char *key;
+	/* Can be negative to indicate lookup by line name */
+	int offset;
+
+	enum gpio_lookup_flags flags;
+};
+
+struct gpio_aggregator_pdev_meta {
+	bool init_via_sysfs;
+};
+
 static DEFINE_MUTEX(gpio_aggregator_lock);	/* protects idr */
 static DEFINE_IDR(gpio_aggregator_idr);
 
-static int aggr_add_gpio(struct gpio_aggregator *aggr, const char *key,
-			 int hwnum, unsigned int *n)
+static int gpio_aggregator_alloc(struct gpio_aggregator **aggr, size_t arg_size)
 {
-	struct gpiod_lookup_table *lookups;
+	int ret;
 
-	lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2),
-			   GFP_KERNEL);
-	if (!lookups)
+	struct gpio_aggregator *new __free(kfree) = kzalloc(
+					sizeof(*new) + arg_size, GFP_KERNEL);
+	if (!new)
 		return -ENOMEM;
 
-	lookups->table[*n] = GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0);
+	scoped_guard(mutex, &gpio_aggregator_lock)
+		ret = idr_alloc(&gpio_aggregator_idr, new, 0, 0, GFP_KERNEL);
 
-	(*n)++;
-	memset(&lookups->table[*n], 0, sizeof(lookups->table[*n]));
+	if (ret < 0)
+		return ret;
 
-	aggr->lookups = lookups;
+	new->id = ret;
+	INIT_LIST_HEAD(&new->list_head);
+	mutex_init(&new->lock);
+	*aggr = no_free_ptr(new);
 	return 0;
 }
 
-static int aggr_parse(struct gpio_aggregator *aggr)
+static void gpio_aggregator_free(struct gpio_aggregator *aggr)
 {
-	char *args = skip_spaces(aggr->args);
-	char *name, *offsets, *p;
-	unsigned int i, n = 0;
-	int error = 0;
-
-	unsigned long *bitmap __free(bitmap) =
-			bitmap_alloc(AGGREGATOR_MAX_GPIOS, GFP_KERNEL);
-	if (!bitmap)
-		return -ENOMEM;
-
-	args = next_arg(args, &name, &p);
-	while (*args) {
-		args = next_arg(args, &offsets, &p);
-
-		p = get_options(offsets, 0, &error);
-		if (error == 0 || *p) {
-			/* Named GPIO line */
-			error = aggr_add_gpio(aggr, name, U16_MAX, &n);
-			if (error)
-				return error;
+	scoped_guard(mutex, &gpio_aggregator_lock)
+		idr_remove(&gpio_aggregator_idr, aggr->id);
 
-			name = offsets;
-			continue;
-		}
+	mutex_destroy(&aggr->lock);
+	kfree(aggr);
+}
 
-		/* GPIO chip + offset(s) */
-		error = bitmap_parselist(offsets, bitmap, AGGREGATOR_MAX_GPIOS);
-		if (error) {
-			pr_err("Cannot parse %s: %d\n", offsets, error);
-			return error;
-		}
+static int gpio_aggregator_add_gpio(struct gpio_aggregator *aggr,
+				    const char *key, int hwnum, unsigned int *n)
+{
+	struct gpiod_lookup_table *lookups;
 
-		for_each_set_bit(i, bitmap, AGGREGATOR_MAX_GPIOS) {
-			error = aggr_add_gpio(aggr, name, i, &n);
-			if (error)
-				return error;
-		}
+	lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2),
+			   GFP_KERNEL);
+	if (!lookups)
+		return -ENOMEM;
 
-		args = next_arg(args, &name, &p);
-	}
+	lookups->table[*n] = GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0);
 
-	if (!n) {
-		pr_err("No GPIOs specified\n");
-		return -EINVAL;
-	}
+	(*n)++;
+	memset(&lookups->table[*n], 0, sizeof(lookups->table[*n]));
 
+	aggr->lookups = lookups;
 	return 0;
 }
 
-static ssize_t new_device_store(struct device_driver *driver, const char *buf,
-				size_t count)
+static bool gpio_aggregator_is_active(struct gpio_aggregator *aggr)
 {
-	struct gpio_aggregator *aggr;
-	struct platform_device *pdev;
-	int res, id;
+	lockdep_assert_held(&aggr->lock);
 
-	if (!try_module_get(THIS_MODULE))
-		return -ENOENT;
-
-	/* kernfs guarantees string termination, so count + 1 is safe */
-	aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL);
-	if (!aggr) {
-		res = -ENOMEM;
-		goto put_module;
-	}
-
-	memcpy(aggr->args, buf, count + 1);
+	return aggr->probe_data.pdev && platform_get_drvdata(aggr->probe_data.pdev);
+}
 
-	aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
-				GFP_KERNEL);
-	if (!aggr->lookups) {
-		res = -ENOMEM;
-		goto free_ga;
-	}
+/* Only aggregators created via legacy sysfs can be "activating". */
+static bool gpio_aggregator_is_activating(struct gpio_aggregator *aggr)
+{
+	lockdep_assert_held(&aggr->lock);
 
-	mutex_lock(&gpio_aggregator_lock);
-	id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
-	mutex_unlock(&gpio_aggregator_lock);
+	return aggr->probe_data.pdev && !platform_get_drvdata(aggr->probe_data.pdev);
+}
 
-	if (id < 0) {
-		res = id;
-		goto free_table;
-	}
+static size_t gpio_aggregator_count_lines(struct gpio_aggregator *aggr)
+{
+	lockdep_assert_held(&aggr->lock);
 
-	aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id);
-	if (!aggr->lookups->dev_id) {
-		res = -ENOMEM;
-		goto remove_idr;
-	}
+	return list_count_nodes(&aggr->list_head);
+}
 
-	res = aggr_parse(aggr);
-	if (res)
-		goto free_dev_id;
+static struct gpio_aggregator_line *
+gpio_aggregator_line_alloc(struct gpio_aggregator *parent, unsigned int idx,
+			   char *key, int offset)
+{
+	struct gpio_aggregator_line *line;
 
-	gpiod_add_lookup_table(aggr->lookups);
+	line = kzalloc(sizeof(*line), GFP_KERNEL);
+	if (!line)
+		return ERR_PTR(-ENOMEM);
 
-	pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0);
-	if (IS_ERR(pdev)) {
-		res = PTR_ERR(pdev);
-		goto remove_table;
+	if (key) {
+		line->key = kstrdup(key, GFP_KERNEL);
+		if (!line->key) {
+			kfree(line);
+			return ERR_PTR(-ENOMEM);
+		}
 	}
 
-	aggr->pdev = pdev;
-	module_put(THIS_MODULE);
-	return count;
+	line->flags = GPIO_LOOKUP_FLAGS_DEFAULT;
+	line->parent = parent;
+	line->idx = idx;
+	line->offset = offset;
+	INIT_LIST_HEAD(&line->entry);
 
-remove_table:
-	gpiod_remove_lookup_table(aggr->lookups);
-free_dev_id:
-	kfree(aggr->lookups->dev_id);
-remove_idr:
-	mutex_lock(&gpio_aggregator_lock);
-	idr_remove(&gpio_aggregator_idr, id);
-	mutex_unlock(&gpio_aggregator_lock);
-free_table:
-	kfree(aggr->lookups);
-free_ga:
-	kfree(aggr);
-put_module:
-	module_put(THIS_MODULE);
-	return res;
-}
-
-static DRIVER_ATTR_WO(new_device);
-
-static void gpio_aggregator_free(struct gpio_aggregator *aggr)
-{
-	platform_device_unregister(aggr->pdev);
-	gpiod_remove_lookup_table(aggr->lookups);
-	kfree(aggr->lookups->dev_id);
-	kfree(aggr->lookups);
-	kfree(aggr);
+	return line;
 }
 
-static ssize_t delete_device_store(struct device_driver *driver,
-				   const char *buf, size_t count)
+static void gpio_aggregator_line_add(struct gpio_aggregator *aggr,
+				     struct gpio_aggregator_line *line)
 {
-	struct gpio_aggregator *aggr;
-	unsigned int id;
-	int error;
+	struct gpio_aggregator_line *tmp;
 
-	if (!str_has_prefix(buf, DRV_NAME "."))
-		return -EINVAL;
+	lockdep_assert_held(&aggr->lock);
 
-	error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id);
-	if (error)
-		return error;
-
-	if (!try_module_get(THIS_MODULE))
-		return -ENOENT;
-
-	mutex_lock(&gpio_aggregator_lock);
-	aggr = idr_remove(&gpio_aggregator_idr, id);
-	mutex_unlock(&gpio_aggregator_lock);
-	if (!aggr) {
-		module_put(THIS_MODULE);
-		return -ENOENT;
+	list_for_each_entry(tmp, &aggr->list_head, entry) {
+		if (tmp->idx > line->idx) {
+			list_add_tail(&line->entry, &tmp->entry);
+			return;
+		}
 	}
-
-	gpio_aggregator_free(aggr);
-	module_put(THIS_MODULE);
-	return count;
+	list_add_tail(&line->entry, &aggr->list_head);
 }
-static DRIVER_ATTR_WO(delete_device);
-
-static struct attribute *gpio_aggregator_attrs[] = {
-	&driver_attr_new_device.attr,
-	&driver_attr_delete_device.attr,
-	NULL
-};
-ATTRIBUTE_GROUPS(gpio_aggregator);
 
-static int __exit gpio_aggregator_idr_remove(int id, void *p, void *data)
+static void gpio_aggregator_line_del(struct gpio_aggregator *aggr,
+				     struct gpio_aggregator_line *line)
 {
-	gpio_aggregator_free(p);
-	return 0;
+	lockdep_assert_held(&aggr->lock);
+
+	list_del(&line->entry);
 }
 
-static void __exit gpio_aggregator_remove_all(void)
+static void gpio_aggregator_free_lines(struct gpio_aggregator *aggr)
 {
-	mutex_lock(&gpio_aggregator_lock);
-	idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL);
-	idr_destroy(&gpio_aggregator_idr);
-	mutex_unlock(&gpio_aggregator_lock);
+	struct gpio_aggregator_line *line, *tmp;
+
+	list_for_each_entry_safe(line, tmp, &aggr->list_head, entry) {
+		configfs_unregister_group(&line->group);
+		/*
+		 * Normally, we acquire aggr->lock within the configfs
+		 * callback. However, in the legacy sysfs interface case,
+		 * calling configfs_(un)register_group while holding
+		 * aggr->lock could cause a deadlock. Fortunately, this is
+		 * unnecessary because the new_device/delete_device path
+		 * and the module unload path are mutually exclusive,
+		 * thanks to an explicit try_module_get. That's why this
+		 * minimal scoped_guard suffices.
+		 */
+		scoped_guard(mutex, &aggr->lock)
+			gpio_aggregator_line_del(aggr, line);
+		kfree(line->key);
+		kfree(line->name);
+		kfree(line);
+	}
 }
 
 
@@ -582,6 +559,728 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 	return fwd;
 }
 
+/*
+ * Configfs interface
+ */
+
+static struct gpio_aggregator *
+to_gpio_aggregator(struct config_item *item)
+{
+	struct config_group *group = to_config_group(item);
+
+	return container_of(group, struct gpio_aggregator, group);
+}
+
+static struct gpio_aggregator_line *
+to_gpio_aggregator_line(struct config_item *item)
+{
+	struct config_group *group = to_config_group(item);
+
+	return container_of(group, struct gpio_aggregator_line, group);
+}
+
+static struct fwnode_handle *
+gpio_aggregator_make_device_sw_node(struct gpio_aggregator *aggr)
+{
+	struct property_entry properties[2];
+	struct gpio_aggregator_line *line;
+	size_t num_lines;
+	int n = 0;
+
+	memset(properties, 0, sizeof(properties));
+
+	num_lines = gpio_aggregator_count_lines(aggr);
+	if (num_lines == 0)
+		return NULL;
+
+	const char **line_names __free(kfree) = kcalloc(
+				num_lines, sizeof(*line_names), GFP_KERNEL);
+	if (!line_names)
+		return ERR_PTR(-ENOMEM);
+
+	/* The list is always sorted as new elements are inserted in order. */
+	list_for_each_entry(line, &aggr->list_head, entry)
+		line_names[n++] = line->name ?: "";
+
+	properties[0] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
+					"gpio-line-names",
+					line_names, num_lines);
+
+	return fwnode_create_software_node(properties, NULL);
+}
+
+static int gpio_aggregator_activate(struct gpio_aggregator *aggr)
+{
+	struct platform_device_info pdevinfo;
+	struct gpio_aggregator_line *line;
+	struct fwnode_handle *swnode;
+	unsigned int n = 0;
+	int ret = 0;
+
+	if (gpio_aggregator_count_lines(aggr) == 0)
+		return -EINVAL;
+
+	aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
+				GFP_KERNEL);
+	if (!aggr->lookups)
+		return -ENOMEM;
+
+	swnode = gpio_aggregator_make_device_sw_node(aggr);
+	if (IS_ERR(swnode)) {
+		ret = PTR_ERR(swnode);
+		goto err_remove_lookups;
+	}
+
+	memset(&pdevinfo, 0, sizeof(pdevinfo));
+	pdevinfo.name = DRV_NAME;
+	pdevinfo.id = aggr->id;
+	pdevinfo.fwnode = swnode;
+
+	/* The list is always sorted as new elements are inserted in order. */
+	list_for_each_entry(line, &aggr->list_head, entry) {
+		/*
+		 * - Either GPIO chip label or line name must be configured
+		 *   (i.e. line->key must be non-NULL)
+		 * - Line directories must be named with sequential numeric
+		 *   suffixes starting from 0. (i.e. ./line0, ./line1, ...)
+		 */
+		if (!line->key || line->idx != n) {
+			ret = -EINVAL;
+			goto err_remove_swnode;
+		}
+
+		if (line->offset < 0)
+			ret = gpio_aggregator_add_gpio(aggr, line->key,
+						       U16_MAX, &n);
+		else
+			ret = gpio_aggregator_add_gpio(aggr, line->key,
+						       line->offset, &n);
+		if (ret)
+			goto err_remove_swnode;
+	}
+
+	aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, aggr->id);
+	if (!aggr->lookups->dev_id) {
+		ret = -ENOMEM;
+		goto err_remove_swnode;
+	}
+
+	gpiod_add_lookup_table(aggr->lookups);
+
+	ret = dev_sync_probe_register(&aggr->probe_data, &pdevinfo);
+	if (ret)
+		goto err_remove_lookup_table;
+
+	return 0;
+
+err_remove_lookup_table:
+	kfree(aggr->lookups->dev_id);
+	gpiod_remove_lookup_table(aggr->lookups);
+err_remove_swnode:
+	fwnode_remove_software_node(swnode);
+err_remove_lookups:
+	kfree(aggr->lookups);
+
+	return ret;
+}
+
+static void gpio_aggregator_deactivate(struct gpio_aggregator *aggr)
+{
+	dev_sync_probe_unregister(&aggr->probe_data);
+	gpiod_remove_lookup_table(aggr->lookups);
+	kfree(aggr->lookups->dev_id);
+	kfree(aggr->lookups);
+}
+
+static void gpio_aggregator_lockup_configfs(struct gpio_aggregator *aggr,
+					    bool lock)
+{
+	struct configfs_subsystem *subsys = aggr->group.cg_subsys;
+	struct gpio_aggregator_line *line;
+
+	/*
+	 * The device only needs to depend on leaf lines. This is
+	 * sufficient to lock up all the configfs entries that the
+	 * instantiated, alive device depends on.
+	 */
+	list_for_each_entry(line, &aggr->list_head, entry) {
+		if (lock)
+			configfs_depend_item_unlocked(
+					subsys, &line->group.cg_item);
+		else
+			configfs_undepend_item_unlocked(
+					&line->group.cg_item);
+	}
+}
+
+static ssize_t
+gpio_aggregator_line_key_show(struct config_item *item, char *page)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+
+	guard(mutex)(&aggr->lock);
+
+	return sysfs_emit(page, "%s\n", line->key ?: "");
+}
+
+static ssize_t
+gpio_aggregator_line_key_store(struct config_item *item, const char *page,
+			       size_t count)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+
+	char *key __free(kfree) = kstrndup(skip_spaces(page), count,
+					   GFP_KERNEL);
+	if (!key)
+		return -ENOMEM;
+
+	strim(key);
+
+	guard(mutex)(&aggr->lock);
+
+	if (gpio_aggregator_is_activating(aggr) ||
+	    gpio_aggregator_is_active(aggr))
+		return -EBUSY;
+
+	kfree(line->key);
+	line->key = no_free_ptr(key);
+
+	return count;
+}
+CONFIGFS_ATTR(gpio_aggregator_line_, key);
+
+static ssize_t
+gpio_aggregator_line_name_show(struct config_item *item, char *page)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+
+	guard(mutex)(&aggr->lock);
+
+	return sysfs_emit(page, "%s\n", line->name ?: "");
+}
+
+static ssize_t
+gpio_aggregator_line_name_store(struct config_item *item, const char *page,
+				size_t count)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+
+	char *name __free(kfree) = kstrndup(skip_spaces(page), count,
+					    GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	strim(name);
+
+	guard(mutex)(&aggr->lock);
+
+	if (gpio_aggregator_is_activating(aggr) ||
+	    gpio_aggregator_is_active(aggr))
+		return -EBUSY;
+
+	kfree(line->name);
+	line->name = no_free_ptr(name);
+
+	return count;
+}
+CONFIGFS_ATTR(gpio_aggregator_line_, name);
+
+static ssize_t
+gpio_aggregator_line_offset_show(struct config_item *item, char *page)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+
+	guard(mutex)(&aggr->lock);
+
+	return sysfs_emit(page, "%d\n", line->offset);
+}
+
+static ssize_t
+gpio_aggregator_line_offset_store(struct config_item *item, const char *page,
+				  size_t count)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+	int offset, ret;
+
+	ret = kstrtoint(page, 0, &offset);
+	if (ret)
+		return ret;
+
+	/*
+	 * When offset == -1, 'key' represents a line name to lookup.
+	 * When 0 <= offset < 65535, 'key' represents the label of the chip with
+	 * the 'offset' value representing the line within that chip.
+	 *
+	 * GPIOLIB uses the U16_MAX value to indicate lookup by line name so
+	 * the greatest offset we can accept is (U16_MAX - 1).
+	 */
+	if (offset > (U16_MAX - 1) || offset < -1)
+		return -EINVAL;
+
+	guard(mutex)(&aggr->lock);
+
+	if (gpio_aggregator_is_activating(aggr) ||
+	    gpio_aggregator_is_active(aggr))
+		return -EBUSY;
+
+	line->offset = offset;
+
+	return count;
+}
+CONFIGFS_ATTR(gpio_aggregator_line_, offset);
+
+static struct configfs_attribute *gpio_aggregator_line_attrs[] = {
+	&gpio_aggregator_line_attr_key,
+	&gpio_aggregator_line_attr_name,
+	&gpio_aggregator_line_attr_offset,
+	NULL
+};
+
+static ssize_t
+gpio_aggregator_device_dev_name_show(struct config_item *item, char *page)
+{
+	struct gpio_aggregator *aggr = to_gpio_aggregator(item);
+	struct platform_device *pdev;
+
+	guard(mutex)(&aggr->lock);
+
+	pdev = aggr->probe_data.pdev;
+	if (pdev)
+		return sysfs_emit(page, "%s\n", dev_name(&pdev->dev));
+
+	return sysfs_emit(page, "%s.%d\n", DRV_NAME, aggr->id);
+}
+CONFIGFS_ATTR_RO(gpio_aggregator_device_, dev_name);
+
+static ssize_t
+gpio_aggregator_device_live_show(struct config_item *item, char *page)
+{
+	struct gpio_aggregator *aggr = to_gpio_aggregator(item);
+
+	guard(mutex)(&aggr->lock);
+
+	return sysfs_emit(page, "%c\n",
+			  gpio_aggregator_is_active(aggr) ? '1' : '0');
+}
+
+static ssize_t
+gpio_aggregator_device_live_store(struct config_item *item, const char *page,
+				  size_t count)
+{
+	struct gpio_aggregator *aggr = to_gpio_aggregator(item);
+	int ret = 0;
+	bool live;
+
+	ret = kstrtobool(page, &live);
+	if (ret)
+		return ret;
+
+	if (!try_module_get(THIS_MODULE))
+		return -ENOENT;
+
+	if (live && !aggr->init_via_sysfs)
+		gpio_aggregator_lockup_configfs(aggr, true);
+
+	scoped_guard(mutex, &aggr->lock) {
+		if (gpio_aggregator_is_activating(aggr) ||
+		    (live == gpio_aggregator_is_active(aggr)))
+			ret = -EPERM;
+		else if (live)
+			ret = gpio_aggregator_activate(aggr);
+		else
+			gpio_aggregator_deactivate(aggr);
+	}
+
+	/*
+	 * Undepend is required only if device disablement (live == 0)
+	 * succeeds or if device enablement (live == 1) fails.
+	 */
+	if (live == !!ret && !aggr->init_via_sysfs)
+		gpio_aggregator_lockup_configfs(aggr, false);
+
+	module_put(THIS_MODULE);
+
+	return ret ?: count;
+}
+CONFIGFS_ATTR(gpio_aggregator_device_, live);
+
+static struct configfs_attribute *gpio_aggregator_device_attrs[] = {
+	&gpio_aggregator_device_attr_dev_name,
+	&gpio_aggregator_device_attr_live,
+	NULL
+};
+
+static void
+gpio_aggregator_line_release(struct config_item *item)
+{
+	struct gpio_aggregator_line *line = to_gpio_aggregator_line(item);
+	struct gpio_aggregator *aggr = line->parent;
+
+	guard(mutex)(&aggr->lock);
+
+	gpio_aggregator_line_del(aggr, line);
+	kfree(line->key);
+	kfree(line->name);
+	kfree(line);
+}
+
+static struct configfs_item_operations gpio_aggregator_line_item_ops = {
+	.release	= gpio_aggregator_line_release,
+};
+
+static const struct config_item_type gpio_aggregator_line_type = {
+	.ct_item_ops	= &gpio_aggregator_line_item_ops,
+	.ct_attrs	= gpio_aggregator_line_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static void gpio_aggregator_device_release(struct config_item *item)
+{
+	struct gpio_aggregator *aggr = to_gpio_aggregator(item);
+
+	/*
+	 * At this point, aggr is neither active nor activating,
+	 * so calling gpio_aggregator_deactivate() is always unnecessary.
+	 */
+	gpio_aggregator_free(aggr);
+}
+
+static struct configfs_item_operations gpio_aggregator_device_item_ops = {
+	.release	= gpio_aggregator_device_release,
+};
+
+static struct config_group *
+gpio_aggregator_device_make_group(struct config_group *group, const char *name)
+{
+	struct gpio_aggregator *aggr = to_gpio_aggregator(&group->cg_item);
+	struct gpio_aggregator_line *line;
+	unsigned int idx;
+	int ret, nchar;
+
+	ret = sscanf(name, "line%u%n", &idx, &nchar);
+	if (ret != 1 || nchar != strlen(name))
+		return ERR_PTR(-EINVAL);
+
+	if (aggr->init_via_sysfs)
+		/*
+		 * Aggregators created via legacy sysfs interface are exposed as
+		 * default groups, which means rmdir(2) is prohibited for them.
+		 * For simplicity, and to avoid confusion, we also prohibit
+		 * mkdir(2).
+		 */
+		return ERR_PTR(-EPERM);
+
+	guard(mutex)(&aggr->lock);
+
+	if (gpio_aggregator_is_active(aggr))
+		return ERR_PTR(-EBUSY);
+
+	list_for_each_entry(line, &aggr->list_head, entry)
+		if (line->idx == idx)
+			return ERR_PTR(-EINVAL);
+
+	line = gpio_aggregator_line_alloc(aggr, idx, NULL, -1);
+	if (IS_ERR(line))
+		return ERR_CAST(line);
+
+	config_group_init_type_name(&line->group, name, &gpio_aggregator_line_type);
+
+	gpio_aggregator_line_add(aggr, line);
+
+	return &line->group;
+}
+
+static struct configfs_group_operations gpio_aggregator_device_group_ops = {
+	.make_group	= gpio_aggregator_device_make_group,
+};
+
+static const struct config_item_type gpio_aggregator_device_type = {
+	.ct_group_ops	= &gpio_aggregator_device_group_ops,
+	.ct_item_ops	= &gpio_aggregator_device_item_ops,
+	.ct_attrs	= gpio_aggregator_device_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct config_group *
+gpio_aggregator_make_group(struct config_group *group, const char *name)
+{
+	struct gpio_aggregator *aggr;
+	int ret;
+
+	/*
+	 * "_sysfs" prefix is reserved for auto-generated config group
+	 * for devices create via legacy sysfs interface.
+	 */
+	if (strncmp(name, AGGREGATOR_LEGACY_PREFIX,
+		    sizeof(AGGREGATOR_LEGACY_PREFIX) - 1) == 0)
+		return ERR_PTR(-EINVAL);
+
+	/* arg space is unneeded */
+	ret = gpio_aggregator_alloc(&aggr, 0);
+	if (ret)
+		return ERR_PTR(ret);
+
+	config_group_init_type_name(&aggr->group, name, &gpio_aggregator_device_type);
+	dev_sync_probe_init(&aggr->probe_data);
+
+	return &aggr->group;
+}
+
+static struct configfs_group_operations gpio_aggregator_group_ops = {
+	.make_group	= gpio_aggregator_make_group,
+};
+
+static const struct config_item_type gpio_aggregator_type = {
+	.ct_group_ops	= &gpio_aggregator_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct configfs_subsystem gpio_aggregator_subsys = {
+	.su_group = {
+		.cg_item = {
+			.ci_namebuf	= DRV_NAME,
+			.ci_type	= &gpio_aggregator_type,
+		},
+	},
+};
+
+/*
+ * Sysfs interface
+ */
+static int gpio_aggregator_parse(struct gpio_aggregator *aggr)
+{
+	char *args = skip_spaces(aggr->args);
+	struct gpio_aggregator_line *line;
+	char name[CONFIGFS_ITEM_NAME_LEN];
+	char *key, *offsets, *p;
+	unsigned int i, n = 0;
+	int error = 0;
+
+	unsigned long *bitmap __free(bitmap) =
+			bitmap_alloc(AGGREGATOR_MAX_GPIOS, GFP_KERNEL);
+	if (!bitmap)
+		return -ENOMEM;
+
+	args = next_arg(args, &key, &p);
+	while (*args) {
+		args = next_arg(args, &offsets, &p);
+
+		p = get_options(offsets, 0, &error);
+		if (error == 0 || *p) {
+			/* Named GPIO line */
+			scnprintf(name, sizeof(name), "line%u", n);
+			line = gpio_aggregator_line_alloc(aggr, n, key, -1);
+			if (IS_ERR(line)) {
+				error = PTR_ERR(line);
+				goto err;
+			}
+			config_group_init_type_name(&line->group, name,
+						    &gpio_aggregator_line_type);
+			error = configfs_register_group(&aggr->group,
+							&line->group);
+			if (error)
+				goto err;
+			scoped_guard(mutex, &aggr->lock)
+				gpio_aggregator_line_add(aggr, line);
+
+			error = gpio_aggregator_add_gpio(aggr, key, U16_MAX, &n);
+			if (error)
+				goto err;
+
+			key = offsets;
+			continue;
+		}
+
+		/* GPIO chip + offset(s) */
+		error = bitmap_parselist(offsets, bitmap, AGGREGATOR_MAX_GPIOS);
+		if (error) {
+			pr_err("Cannot parse %s: %d\n", offsets, error);
+			goto err;
+		}
+
+		for_each_set_bit(i, bitmap, AGGREGATOR_MAX_GPIOS) {
+			scnprintf(name, sizeof(name), "line%u", n);
+			line = gpio_aggregator_line_alloc(aggr, n, key, i);
+			if (IS_ERR(line)) {
+				error = PTR_ERR(line);
+				goto err;
+			}
+			config_group_init_type_name(&line->group, name,
+						    &gpio_aggregator_line_type);
+			error = configfs_register_group(&aggr->group,
+							&line->group);
+			if (error)
+				goto err;
+			scoped_guard(mutex, &aggr->lock)
+				gpio_aggregator_line_add(aggr, line);
+
+			error = gpio_aggregator_add_gpio(aggr, key, i, &n);
+			if (error)
+				goto err;
+		}
+
+		args = next_arg(args, &key, &p);
+	}
+
+	if (!n) {
+		pr_err("No GPIOs specified\n");
+		error = -EINVAL;
+		goto err;
+	}
+
+	return 0;
+
+err:
+	gpio_aggregator_free_lines(aggr);
+	return error;
+}
+
+static ssize_t gpio_aggregator_new_device_store(struct device_driver *driver,
+						const char *buf, size_t count)
+{
+	struct gpio_aggregator_pdev_meta meta = { .init_via_sysfs = true };
+	char name[CONFIGFS_ITEM_NAME_LEN];
+	struct gpio_aggregator *aggr;
+	struct platform_device *pdev;
+	int res;
+
+	if (!try_module_get(THIS_MODULE))
+		return -ENOENT;
+
+	/* kernfs guarantees string termination, so count + 1 is safe */
+	res = gpio_aggregator_alloc(&aggr, count + 1);
+	if (res)
+		goto put_module;
+
+	memcpy(aggr->args, buf, count + 1);
+
+	aggr->init_via_sysfs = true;
+	aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
+				GFP_KERNEL);
+	if (!aggr->lookups) {
+		res = -ENOMEM;
+		goto free_ga;
+	}
+
+	aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, aggr->id);
+	if (!aggr->lookups->dev_id) {
+		res = -ENOMEM;
+		goto free_table;
+	}
+
+	scnprintf(name, sizeof(name), "%s.%d", AGGREGATOR_LEGACY_PREFIX, aggr->id);
+	config_group_init_type_name(&aggr->group, name, &gpio_aggregator_device_type);
+
+	/*
+	 * Since the device created by sysfs might be toggled via configfs
+	 * 'live' attribute later, this initialization is needed.
+	 */
+	dev_sync_probe_init(&aggr->probe_data);
+
+	/* Expose to configfs */
+	res = configfs_register_group(&gpio_aggregator_subsys.su_group,
+				      &aggr->group);
+	if (res)
+		goto free_dev_id;
+
+	res = gpio_aggregator_parse(aggr);
+	if (res)
+		goto unregister_group;
+
+	gpiod_add_lookup_table(aggr->lookups);
+
+	pdev = platform_device_register_data(NULL, DRV_NAME, aggr->id, &meta, sizeof(meta));
+	if (IS_ERR(pdev)) {
+		res = PTR_ERR(pdev);
+		goto remove_table;
+	}
+
+	aggr->probe_data.pdev = pdev;
+	module_put(THIS_MODULE);
+	return count;
+
+remove_table:
+	gpiod_remove_lookup_table(aggr->lookups);
+unregister_group:
+	configfs_unregister_group(&aggr->group);
+free_dev_id:
+	kfree(aggr->lookups->dev_id);
+free_table:
+	kfree(aggr->lookups);
+free_ga:
+	gpio_aggregator_free(aggr);
+put_module:
+	module_put(THIS_MODULE);
+	return res;
+}
+
+static struct driver_attribute driver_attr_gpio_aggregator_new_device =
+	__ATTR(new_device, 0200, NULL, gpio_aggregator_new_device_store);
+
+static void gpio_aggregator_destroy(struct gpio_aggregator *aggr)
+{
+	scoped_guard(mutex, &aggr->lock) {
+		if (gpio_aggregator_is_activating(aggr) ||
+		    gpio_aggregator_is_active(aggr))
+			gpio_aggregator_deactivate(aggr);
+	}
+	gpio_aggregator_free_lines(aggr);
+	configfs_unregister_group(&aggr->group);
+	kfree(aggr);
+}
+
+static ssize_t gpio_aggregator_delete_device_store(struct device_driver *driver,
+						   const char *buf, size_t count)
+{
+	struct gpio_aggregator *aggr;
+	unsigned int id;
+	int error;
+
+	if (!str_has_prefix(buf, DRV_NAME "."))
+		return -EINVAL;
+
+	error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id);
+	if (error)
+		return error;
+
+	if (!try_module_get(THIS_MODULE))
+		return -ENOENT;
+
+	mutex_lock(&gpio_aggregator_lock);
+	aggr = idr_find(&gpio_aggregator_idr, id);
+	/*
+	 * For simplicity, devices created via configfs cannot be deleted
+	 * via sysfs.
+	 */
+	if (aggr && aggr->init_via_sysfs)
+		idr_remove(&gpio_aggregator_idr, id);
+	else {
+		mutex_unlock(&gpio_aggregator_lock);
+		module_put(THIS_MODULE);
+		return -ENOENT;
+	}
+	mutex_unlock(&gpio_aggregator_lock);
+
+	gpio_aggregator_destroy(aggr);
+	module_put(THIS_MODULE);
+	return count;
+}
+
+static struct driver_attribute driver_attr_gpio_aggregator_delete_device =
+	__ATTR(delete_device, 0200, NULL, gpio_aggregator_delete_device_store);
+
+static struct attribute *gpio_aggregator_attrs[] = {
+	&driver_attr_gpio_aggregator_new_device.attr,
+	&driver_attr_gpio_aggregator_delete_device.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(gpio_aggregator);
 
 /*
  *  GPIO Aggregator platform device
@@ -589,7 +1288,9 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 
 static int gpio_aggregator_probe(struct platform_device *pdev)
 {
+	struct gpio_aggregator_pdev_meta *meta;
 	struct device *dev = &pdev->dev;
+	bool init_via_sysfs = false;
 	struct gpio_desc **descs;
 	struct gpiochip_fwd *fwd;
 	unsigned long features;
@@ -603,10 +1304,28 @@ static int gpio_aggregator_probe(struct platform_device *pdev)
 	if (!descs)
 		return -ENOMEM;
 
+	meta = dev_get_platdata(&pdev->dev);
+	if (meta && meta->init_via_sysfs)
+		init_via_sysfs = true;
+
 	for (i = 0; i < n; i++) {
 		descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
-		if (IS_ERR(descs[i]))
+		if (IS_ERR(descs[i])) {
+			/*
+			 * Deferred probing is not suitable when the aggregator
+			 * is created via configfs. They should just retry later
+			 * whenever they like. For device creation via sysfs,
+			 * error is propagated without overriding for backward
+			 * compatibility. .prevent_deferred_probe is kept unset
+			 * for other cases.
+			 */
+			if (!init_via_sysfs && !dev_of_node(dev) &&
+			    descs[i] == ERR_PTR(-EPROBE_DEFER)) {
+				pr_warn("Deferred probe canceled for creation via configfs.\n");
+				return -ENODEV;
+			}
 			return PTR_ERR(descs[i]);
+		}
 	}
 
 	features = (uintptr_t)device_get_match_data(dev);
@@ -640,9 +1359,63 @@ static struct platform_driver gpio_aggregator_driver = {
 	},
 };
 
+static int __exit gpio_aggregator_idr_remove(int id, void *p, void *data)
+{
+	/*
+	 * There should be no aggregator created via configfs, as their
+	 * presence would prevent module unloading.
+	 */
+	gpio_aggregator_destroy(p);
+	return 0;
+}
+
+static void __exit gpio_aggregator_remove_all(void)
+{
+	/*
+	 * Configfs callbacks acquire gpio_aggregator_lock when accessing
+	 * gpio_aggregator_idr, so to prevent lock inversion deadlock, we
+	 * cannot protect idr_for_each invocation here with
+	 * gpio_aggregator_lock, as gpio_aggregator_idr_remove() accesses
+	 * configfs groups. Fortunately, the new_device/delete_device path
+	 * and the module unload path are mutually exclusive, thanks to an
+	 * explicit try_module_get inside of those driver attr handlers.
+	 * Also, when we reach here, no configfs entries present or being
+	 * created. Therefore, no need to protect with gpio_aggregator_lock
+	 * below.
+	 */
+	idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL);
+	idr_destroy(&gpio_aggregator_idr);
+}
+
 static int __init gpio_aggregator_init(void)
 {
-	return platform_driver_register(&gpio_aggregator_driver);
+	int ret = 0;
+
+	config_group_init(&gpio_aggregator_subsys.su_group);
+	mutex_init(&gpio_aggregator_subsys.su_mutex);
+	ret = configfs_register_subsystem(&gpio_aggregator_subsys);
+	if (ret) {
+		pr_err("Failed to register the '%s' configfs subsystem: %d\n",
+		       gpio_aggregator_subsys.su_group.cg_item.ci_namebuf, ret);
+		mutex_destroy(&gpio_aggregator_subsys.su_mutex);
+		return ret;
+	}
+
+	/*
+	 * CAVEAT: This must occur after configfs registration. Otherwise,
+	 * a race condition could arise: driver attribute groups might be
+	 * exposed and accessed by users before configfs registration
+	 * completes. new_device_store() does not expect a partially
+	 * initialized configfs state.
+	 */
+	ret = platform_driver_register(&gpio_aggregator_driver);
+	if (ret) {
+		pr_err("Failed to register the platform driver: %d\n", ret);
+		mutex_destroy(&gpio_aggregator_subsys.su_mutex);
+		configfs_unregister_subsystem(&gpio_aggregator_subsys);
+	}
+
+	return ret;
 }
 module_init(gpio_aggregator_init);
 
@@ -650,6 +1423,7 @@ static void __exit gpio_aggregator_exit(void)
 {
 	gpio_aggregator_remove_all();
 	platform_driver_unregister(&gpio_aggregator_driver);
+	configfs_unregister_subsystem(&gpio_aggregator_subsys);
 }
 module_exit(gpio_aggregator_exit);