1 files changed, 281 insertions, 167 deletions

diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index 271db3639a78..a83f5238427c 100644
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -7,11 +7,13 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/array_size.h>
 #include <linux/bitmap.h>
 #include <linux/cleanup.h>
-#include <linux/completion.h>
 #include <linux/configfs.h>
 #include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 #include <linux/gpio/machine.h>
 #include <linux/idr.h>
@@ -19,27 +21,33 @@
 #include <linux/irq.h>
 #include <linux/irq_sim.h>
 #include <linux/list.h>
+#include <linux/lockdep.h>
+#include <linux/minmax.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/notifier.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/string_helpers.h>
 #include <linux/sysfs.h>
+#include <linux/types.h>
 
-#include "gpiolib.h"
+#include "dev-sync-probe.h"
 
 #define GPIO_SIM_NGPIO_MAX	1024
-#define GPIO_SIM_PROP_MAX	4 /* Max 3 properties + sentinel. */
+#define GPIO_SIM_PROP_MAX	5 /* Max 4 properties + sentinel. */
 #define GPIO_SIM_NUM_ATTRS	3 /* value, pull and sentinel */
 
 static DEFINE_IDA(gpio_sim_ida);
 
 struct gpio_sim_chip {
 	struct gpio_chip gc;
+	struct device *dev;
+	unsigned long *request_map;
 	unsigned long *direction_map;
 	unsigned long *value_map;
 	unsigned long *pull_map;
@@ -63,16 +71,11 @@ static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
 			       unsigned int offset, int value)
 {
 	int irq, irq_type, ret;
-	struct gpio_desc *desc;
-	struct gpio_chip *gc;
-
-	gc = &chip->gc;
-	desc = &gc->gpiodev->descs[offset];
 
 	guard(mutex)(&chip->lock);
 
-	if (test_bit(FLAG_REQUESTED, &desc->flags) &&
-	    !test_bit(FLAG_IS_OUT, &desc->flags)) {
+	if (test_bit(offset, chip->request_map) &&
+	    test_bit(offset, chip->direction_map)) {
 		if (value == !!test_bit(offset, chip->value_map))
 			goto set_pull;
 
@@ -99,8 +102,8 @@ static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
 
 set_value:
 	/* Change the value unless we're actively driving the line. */
-	if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
-	    !test_bit(FLAG_IS_OUT, &desc->flags))
+	if (!test_bit(offset, chip->request_map) ||
+	    test_bit(offset, chip->direction_map))
 		__assign_bit(offset, chip->value_map, value);
 
 set_pull:
@@ -117,12 +120,14 @@ static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset)
 	return !!test_bit(offset, chip->value_map);
 }
 
-static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
+static int gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
 
 	scoped_guard(mutex, &chip->lock)
 		__assign_bit(offset, chip->value_map, value);
+
+	return 0;
 }
 
 static int gpio_sim_get_multiple(struct gpio_chip *gc,
@@ -136,14 +141,16 @@ static int gpio_sim_get_multiple(struct gpio_chip *gc,
 	return 0;
 }
 
-static void gpio_sim_set_multiple(struct gpio_chip *gc,
-				  unsigned long *mask, unsigned long *bits)
+static int gpio_sim_set_multiple(struct gpio_chip *gc,
+				 unsigned long *mask, unsigned long *bits)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
 
 	scoped_guard(mutex, &chip->lock)
 		bitmap_replace(chip->value_map, chip->value_map, bits, mask,
 			       gc->ngpio);
+
+	return 0;
 }
 
 static int gpio_sim_direction_output(struct gpio_chip *gc,
@@ -180,8 +187,8 @@ static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset)
 	return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
 }
 
-static int gpio_sim_set_config(struct gpio_chip *gc,
-				  unsigned int offset, unsigned long config)
+static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset,
+			       unsigned long config)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
 
@@ -204,13 +211,64 @@ static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset)
 	return irq_create_mapping(chip->irq_sim, offset);
 }
 
-static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
+static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
 
 	scoped_guard(mutex, &chip->lock)
+		__set_bit(offset, chip->request_map);
+
+	return 0;
+}
+
+static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
+{
+	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+	scoped_guard(mutex, &chip->lock) {
 		__assign_bit(offset, chip->value_map,
 			     !!test_bit(offset, chip->pull_map));
+		__clear_bit(offset, chip->request_map);
+	}
+}
+
+static int gpio_sim_irq_requested(struct irq_domain *domain,
+				  irq_hw_number_t hwirq, void *data)
+{
+	struct gpio_sim_chip *chip = data;
+
+	return gpiochip_lock_as_irq(&chip->gc, hwirq);
+}
+
+static void gpio_sim_irq_released(struct irq_domain *domain,
+				  irq_hw_number_t hwirq, void *data)
+{
+	struct gpio_sim_chip *chip = data;
+
+	gpiochip_unlock_as_irq(&chip->gc, hwirq);
+}
+
+static const struct irq_sim_ops gpio_sim_irq_sim_ops = {
+	.irq_sim_irq_requested = gpio_sim_irq_requested,
+	.irq_sim_irq_released = gpio_sim_irq_released,
+};
+
+static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
+{
+	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+	const char *label;
+	int i;
+
+	guard(mutex)(&chip->lock);
+
+	for_each_hwgpio(gc, i, label)
+		seq_printf(seq, " gpio-%-3d (%s) %s,%s\n", i,
+			   label ?: "<unused>",
+			   test_bit(i, chip->direction_map) ? "input" :
+				test_bit(i, chip->value_map) ? "output-high" :
+							       "output-low",
+			   test_bit(i, chip->pull_map) ? "pull-up" :
+							 "pull-down");
 }
 
 static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
@@ -275,11 +333,11 @@ static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
 	return len;
 }
 
-static void gpio_sim_mutex_destroy(void *data)
+static void gpio_sim_put_device(void *data)
 {
-	struct mutex *lock = data;
+	struct device *dev = data;
 
-	mutex_destroy(lock);
+	put_device(dev);
 }
 
 static void gpio_sim_dispose_mappings(void *data)
@@ -295,7 +353,7 @@ static void gpio_sim_sysfs_remove(void *data)
 {
 	struct gpio_sim_chip *chip = data;
 
-	sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups);
+	sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups);
 }
 
 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
@@ -352,8 +410,7 @@ static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
 		chip->attr_groups[i] = attr_group;
 	}
 
-	ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj,
-				  chip->attr_groups);
+	ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups);
 	if (ret)
 		return ret;
 
@@ -377,7 +434,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 
 	ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
 	if (ret) {
-		label = devm_kasprintf(dev, GFP_KERNEL, "%s-%pfwP",
+		label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP",
 				       dev_name(dev), swnode);
 		if (!label)
 			return -ENOMEM;
@@ -387,6 +444,10 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	if (!chip)
 		return -ENOMEM;
 
+	chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
+	if (!chip->request_map)
+		return -ENOMEM;
+
 	chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
 	if (!chip->direction_map)
 		return -ENOMEM;
@@ -402,7 +463,9 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	if (!chip->pull_map)
 		return -ENOMEM;
 
-	chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines);
+	chip->irq_sim = devm_irq_domain_create_sim_full(dev, swnode, num_lines,
+							&gpio_sim_irq_sim_ops,
+							chip);
 	if (IS_ERR(chip->irq_sim))
 		return PTR_ERR(chip->irq_sim);
 
@@ -410,9 +473,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	if (ret)
 		return ret;
 
-	mutex_init(&chip->lock);
-	ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy,
-				       &chip->lock);
+	ret = devm_mutex_init(dev, &chip->lock);
 	if (ret)
 		return ret;
 
@@ -432,15 +493,25 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 	gc->get_direction = gpio_sim_get_direction;
 	gc->set_config = gpio_sim_set_config;
 	gc->to_irq = gpio_sim_to_irq;
+	gc->request = gpio_sim_request;
 	gc->free = gpio_sim_free;
+	gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show);
 	gc->can_sleep = true;
 
 	ret = devm_gpiochip_add_data(dev, gc, chip);
 	if (ret)
 		return ret;
 
-	/* Used by sysfs and configfs callbacks. */
-	dev_set_drvdata(&gc->gpiodev->dev, chip);
+	chip->dev = device_find_child(dev, swnode, device_match_fwnode);
+	if (!chip->dev)
+		return -ENODEV;
+
+	ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev);
+	if (ret)
+		return ret;
+
+	/* Used by sysfs callbacks. */
+	dev_set_drvdata(chip->dev, chip);
 
 	return gpio_sim_setup_sysfs(chip);
 }
@@ -448,15 +519,12 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
 static int gpio_sim_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct fwnode_handle *swnode;
 	int ret;
 
-	device_for_each_child_node(dev, swnode) {
+	device_for_each_child_node_scoped(dev, swnode) {
 		ret = gpio_sim_add_bank(swnode, dev);
-		if (ret) {
-			fwnode_handle_put(swnode);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;
@@ -477,14 +545,9 @@ static struct platform_driver gpio_sim_driver = {
 };
 
 struct gpio_sim_device {
+	struct dev_sync_probe_data probe_data;
 	struct config_group group;
 
-	/*
-	 * If pdev is NULL, the device is 'pending' (waiting for configuration).
-	 * Once the pointer is assigned, the device has been created and the
-	 * item is 'live'.
-	 */
-	struct platform_device *pdev;
 	int id;
 
 	/*
@@ -498,46 +561,11 @@ struct gpio_sim_device {
 	 */
 	struct mutex lock;
 
-	/*
-	 * This is used to synchronously wait for the driver's probe to complete
-	 * and notify the user-space about any errors.
-	 */
-	struct notifier_block bus_notifier;
-	struct completion probe_completion;
-	bool driver_bound;
-
 	struct gpiod_hog *hogs;
 
 	struct list_head bank_list;
 };
 
-/* This is called with dev->lock already taken. */
-static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
-				      unsigned long action, void *data)
-{
-	struct gpio_sim_device *simdev = container_of(nb,
-						      struct gpio_sim_device,
-						      bus_notifier);
-	struct device *dev = data;
-	char devname[32];
-
-	snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
-
-	if (strcmp(dev_name(dev), devname) == 0) {
-		if (action == BUS_NOTIFY_BOUND_DRIVER)
-			simdev->driver_bound = true;
-		else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND)
-			simdev->driver_bound = false;
-		else
-			return NOTIFY_DONE;
-
-		complete(&simdev->probe_completion);
-		return NOTIFY_OK;
-	}
-
-	return NOTIFY_DONE;
-}
-
 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
 {
 	struct config_group *group = to_config_group(item);
@@ -600,6 +628,7 @@ struct gpio_sim_line {
 
 	unsigned int offset;
 	char *name;
+	bool valid;
 
 	/* There can only be one hog per line. */
 	struct gpio_sim_hog *hog;
@@ -640,9 +669,11 @@ static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
 	return gpio_sim_line_get_device(line);
 }
 
-static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev)
+static bool gpio_sim_device_is_live(struct gpio_sim_device *dev)
 {
-	return !!dev->pdev;
+	lockdep_assert_held(&dev->lock);
+
+	return !!dev->probe_data.pdev;
 }
 
 static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
@@ -664,7 +695,7 @@ static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	pdev = dev->pdev;
+	pdev = dev->probe_data.pdev;
 	if (pdev)
 		return sprintf(page, "%s\n", dev_name(&pdev->dev));
 
@@ -680,57 +711,67 @@ gpio_sim_device_config_live_show(struct config_item *item, char *page)
 	bool live;
 
 	scoped_guard(mutex, &dev->lock)
-		live = gpio_sim_device_is_live_unlocked(dev);
+		live = gpio_sim_device_is_live(dev);
 
 	return sprintf(page, "%c\n", live ? '1' : '0');
 }
 
-static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank,
-				       unsigned int *line_names_size)
+static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank)
 {
-	unsigned int max_offset = 0;
-	bool has_line_names = false;
 	struct gpio_sim_line *line;
-	char **line_names;
+	unsigned int size = 0;
 
 	list_for_each_entry(line, &bank->line_list, siblings) {
-		if (line->offset >= bank->num_lines)
+		if (!line->name || (line->offset >= bank->num_lines))
 			continue;
 
-		if (line->name) {
-			if (line->offset > max_offset)
-				max_offset = line->offset;
-
-			/*
-			 * max_offset can stay at 0 so it's not an indicator
-			 * of whether line names were configured at all.
-			 */
-			has_line_names = true;
-		}
+		size = max(size, line->offset + 1);
 	}
 
-	if (!has_line_names)
-		/*
-		 * This is not an error - NULL means, there are no line
-		 * names configured.
-		 */
-		return NULL;
+	return size;
+}
 
-	*line_names_size = max_offset + 1;
+static void
+gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names)
+{
+	struct gpio_sim_line *line;
 
-	line_names = kcalloc(*line_names_size, sizeof(*line_names), GFP_KERNEL);
-	if (!line_names)
-		return ERR_PTR(-ENOMEM);
+	list_for_each_entry(line, &bank->line_list, siblings) {
+		if (!line->name || (line->offset >= bank->num_lines))
+			continue;
+
+		line_names[line->offset] = line->name;
+	}
+}
+
+static unsigned int gpio_sim_get_reserved_ranges_size(struct gpio_sim_bank *bank)
+{
+	struct gpio_sim_line *line;
+	unsigned int size = 0;
 
 	list_for_each_entry(line, &bank->line_list, siblings) {
-		if (line->offset >= bank->num_lines)
+		if (line->valid)
 			continue;
 
-		if (line->name && (line->offset <= max_offset))
-			line_names[line->offset] = line->name;
+		size += 2;
 	}
 
-	return line_names;
+	return size;
+}
+
+static void gpio_sim_set_reserved_ranges(struct gpio_sim_bank *bank,
+					 u32 *ranges)
+{
+	struct gpio_sim_line *line;
+	int i = 0;
+
+	list_for_each_entry(line, &bank->line_list, siblings) {
+		if (line->valid)
+			continue;
+
+		ranges[i++] = line->offset;
+		ranges[i++] = 1;
+	}
 }
 
 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
@@ -796,7 +837,7 @@ static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
 							  GFP_KERNEL);
 			else
 				hog->chip_label = kasprintf(GFP_KERNEL,
-							"gpio-sim.%u-%pfwP",
+							"gpio-sim.%u:%pfwP",
 							dev->id,
 							bank->swnode);
 			if (!hog->chip_label) {
@@ -833,9 +874,10 @@ static struct fwnode_handle *
 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
 			  struct fwnode_handle *parent)
 {
+	unsigned int prop_idx = 0, line_names_size, ranges_size;
 	struct property_entry properties[GPIO_SIM_PROP_MAX];
-	unsigned int prop_idx = 0, line_names_size = 0;
 	char **line_names __free(kfree) = NULL;
+	u32 *ranges __free(kfree) = NULL;
 
 	memset(properties, 0, sizeof(properties));
 
@@ -845,14 +887,32 @@ gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
 		properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
 							       bank->label);
 
-	line_names = gpio_sim_make_line_names(bank, &line_names_size);
-	if (IS_ERR(line_names))
-		return ERR_CAST(line_names);
+	line_names_size = gpio_sim_get_line_names_size(bank);
+	if (line_names_size) {
+		line_names = kcalloc(line_names_size, sizeof(*line_names),
+				     GFP_KERNEL);
+		if (!line_names)
+			return ERR_PTR(-ENOMEM);
+
+		gpio_sim_set_line_names(bank, line_names);
 
-	if (line_names)
 		properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
 						"gpio-line-names",
 						line_names, line_names_size);
+	}
+
+	ranges_size = gpio_sim_get_reserved_ranges_size(bank);
+	if (ranges_size) {
+		ranges = kcalloc(ranges_size, sizeof(u32), GFP_KERNEL);
+		if (!ranges)
+			return ERR_PTR(-ENOMEM);
+
+		gpio_sim_set_reserved_ranges(bank, ranges);
+
+		properties[prop_idx++] = PROPERTY_ENTRY_U32_ARRAY_LEN(
+						"gpio-reserved-ranges",
+						ranges, ranges_size);
+	}
 
 	return fwnode_create_software_node(properties, parent);
 }
@@ -884,14 +944,15 @@ static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
 	return false;
 }
 
-static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
+static int gpio_sim_device_activate(struct gpio_sim_device *dev)
 {
 	struct platform_device_info pdevinfo;
 	struct fwnode_handle *swnode;
-	struct platform_device *pdev;
 	struct gpio_sim_bank *bank;
 	int ret;
 
+	lockdep_assert_held(&dev->lock);
+
 	if (list_empty(&dev->bank_list))
 		return -ENODATA;
 
@@ -928,43 +989,53 @@ static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
 	pdevinfo.fwnode = swnode;
 	pdevinfo.id = dev->id;
 
-	reinit_completion(&dev->probe_completion);
-	dev->driver_bound = false;
-	bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
-
-	pdev = platform_device_register_full(&pdevinfo);
-	if (IS_ERR(pdev)) {
-		bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
-		gpio_sim_remove_hogs(dev);
-		gpio_sim_remove_swnode_recursive(swnode);
-		return PTR_ERR(pdev);
-	}
-
-	wait_for_completion(&dev->probe_completion);
-	bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
-
-	if (!dev->driver_bound) {
-		/* Probe failed, check kernel log. */
-		platform_device_unregister(pdev);
+	ret = dev_sync_probe_register(&dev->probe_data, &pdevinfo);
+	if (ret) {
 		gpio_sim_remove_hogs(dev);
 		gpio_sim_remove_swnode_recursive(swnode);
-		return -ENXIO;
+		return ret;
 	}
 
-	dev->pdev = pdev;
-
 	return 0;
 }
 
-static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev)
+static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
 {
 	struct fwnode_handle *swnode;
 
-	swnode = dev_fwnode(&dev->pdev->dev);
-	platform_device_unregister(dev->pdev);
+	lockdep_assert_held(&dev->lock);
+
+	swnode = dev_fwnode(&dev->probe_data.pdev->dev);
+	dev_sync_probe_unregister(&dev->probe_data);
 	gpio_sim_remove_hogs(dev);
 	gpio_sim_remove_swnode_recursive(swnode);
-	dev->pdev = NULL;
+}
+
+static void
+gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock)
+{
+	struct configfs_subsystem *subsys = dev->group.cg_subsys;
+	struct gpio_sim_bank *bank;
+	struct gpio_sim_line *line;
+	struct config_item *item;
+
+	/*
+	 * The device only needs to depend on leaf entries. This is
+	 * sufficient to lock up all the configfs entries that the
+	 * instantiated, alive device depends on.
+	 */
+	list_for_each_entry(bank, &dev->bank_list, siblings) {
+		list_for_each_entry(line, &bank->line_list, siblings) {
+			item = line->hog ? &line->hog->item
+					 : &line->group.cg_item;
+
+			if (lock)
+				WARN_ON(configfs_depend_item_unlocked(subsys,
+								      item));
+			else
+				configfs_undepend_item_unlocked(item);
+		}
+	}
 }
 
 static ssize_t
@@ -979,14 +1050,24 @@ gpio_sim_device_config_live_store(struct config_item *item,
 	if (ret)
 		return ret;
 
-	guard(mutex)(&dev->lock);
+	if (live)
+		gpio_sim_device_lockup_configfs(dev, true);
 
-	if (live == gpio_sim_device_is_live_unlocked(dev))
-		ret = -EPERM;
-	else if (live)
-		ret = gpio_sim_device_activate_unlocked(dev);
-	else
-		gpio_sim_device_deactivate_unlocked(dev);
+	scoped_guard(mutex, &dev->lock) {
+		if (live == gpio_sim_device_is_live(dev))
+			ret = -EPERM;
+		else if (live)
+			ret = gpio_sim_device_activate(dev);
+		else
+			gpio_sim_device_deactivate(dev);
+	}
+
+	/*
+	 * Undepend is required only if device disablement (live == 0)
+	 * succeeds or if device enablement (live == 1) fails.
+	 */
+	if (live == !!ret)
+		gpio_sim_device_lockup_configfs(dev, false);
 
 	return ret ?: count;
 }
@@ -1027,8 +1108,8 @@ static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
-		return device_for_each_child(&dev->pdev->dev, &ctx,
+	if (gpio_sim_device_is_live(dev))
+		return device_for_each_child(&dev->probe_data.pdev->dev, &ctx,
 					     gpio_sim_emit_chip_name);
 
 	return sprintf(page, "none\n");
@@ -1056,7 +1137,7 @@ static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	trimmed = gpio_sim_strdup_trimmed(page, count);
@@ -1100,7 +1181,7 @@ gpio_sim_bank_config_num_lines_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	bank->num_lines = num_lines;
@@ -1137,7 +1218,7 @@ static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	trimmed = gpio_sim_strdup_trimmed(page, count);
@@ -1152,8 +1233,41 @@ static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
 
 CONFIGFS_ATTR(gpio_sim_line_config_, name);
 
+static ssize_t
+gpio_sim_line_config_valid_show(struct config_item *item, char *page)
+{
+	struct gpio_sim_line *line = to_gpio_sim_line(item);
+	struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
+
+	guard(mutex)(&dev->lock);
+
+	return sprintf(page, "%c\n", line->valid ? '1' : '0');
+}
+
+static ssize_t gpio_sim_line_config_valid_store(struct config_item *item,
+						const char *page, size_t count)
+{
+	struct gpio_sim_line *line = to_gpio_sim_line(item);
+	struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
+	bool valid;
+	int ret;
+
+	ret = kstrtobool(page, &valid);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&dev->lock);
+
+	line->valid = valid;
+
+	return count;
+}
+
+CONFIGFS_ATTR(gpio_sim_line_config_, valid);
+
 static struct configfs_attribute *gpio_sim_line_config_attrs[] = {
 	&gpio_sim_line_config_attr_name,
+	&gpio_sim_line_config_attr_valid,
 	NULL
 };
 
@@ -1177,7 +1291,7 @@ static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	trimmed = gpio_sim_strdup_trimmed(page, count);
@@ -1232,7 +1346,7 @@ gpio_sim_hog_config_direction_store(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return -EBUSY;
 
 	if (sysfs_streq(page, "input"))
@@ -1350,7 +1464,7 @@ gpio_sim_bank_config_make_line_group(struct config_group *group,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return ERR_PTR(-EBUSY);
 
 	line = kzalloc(sizeof(*line), GFP_KERNEL);
@@ -1362,6 +1476,7 @@ gpio_sim_bank_config_make_line_group(struct config_group *group,
 
 	line->parent = bank;
 	line->offset = offset;
+	line->valid = true;
 	list_add_tail(&line->siblings, &bank->line_list);
 
 	return &line->group;
@@ -1403,7 +1518,7 @@ gpio_sim_device_config_make_bank_group(struct config_group *group,
 
 	guard(mutex)(&dev->lock);
 
-	if (gpio_sim_device_is_live_unlocked(dev))
+	if (gpio_sim_device_is_live(dev))
 		return ERR_PTR(-EBUSY);
 
 	bank = kzalloc(sizeof(*bank), GFP_KERNEL);
@@ -1425,8 +1540,8 @@ static void gpio_sim_device_config_group_release(struct config_item *item)
 	struct gpio_sim_device *dev = to_gpio_sim_device(item);
 
 	scoped_guard(mutex, &dev->lock) {
-		if (gpio_sim_device_is_live_unlocked(dev))
-			gpio_sim_device_deactivate_unlocked(dev);
+		if (gpio_sim_device_is_live(dev))
+			gpio_sim_device_deactivate(dev);
 	}
 
 	mutex_destroy(&dev->lock);
@@ -1452,10 +1567,10 @@ static const struct config_item_type gpio_sim_device_config_group_type = {
 static struct config_group *
 gpio_sim_config_make_device_group(struct config_group *group, const char *name)
 {
-	struct gpio_sim_device *dev __free(kfree) = NULL;
 	int id;
 
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev),
+							    GFP_KERNEL);
 	if (!dev)
 		return ERR_PTR(-ENOMEM);
 
@@ -1469,8 +1584,7 @@ gpio_sim_config_make_device_group(struct config_group *group, const char *name)
 	mutex_init(&dev->lock);
 	INIT_LIST_HEAD(&dev->bank_list);
 
-	dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
-	init_completion(&dev->probe_completion);
+	dev_sync_probe_init(&dev->probe_data);
 
 	return &no_free_ptr(dev)->group;
 }
@@ -1526,6 +1640,6 @@ static void __exit gpio_sim_exit(void)
 }
 module_exit(gpio_sim_exit);
 
-MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl");
+MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
 MODULE_DESCRIPTION("GPIO Simulator Module");
 MODULE_LICENSE("GPL");