1 files changed, 207 insertions, 152 deletions

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 608b352a7d91..980123fb4dde 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -19,29 +19,7 @@
 #include <linux/of.h>
 #include <linux/slab.h>
 
-struct nvmem_device {
-	struct module		*owner;
-	struct device		dev;
-	int			stride;
-	int			word_size;
-	int			id;
-	struct kref		refcnt;
-	size_t			size;
-	bool			read_only;
-	bool			root_only;
-	int			flags;
-	enum nvmem_type		type;
-	struct bin_attribute	eeprom;
-	struct device		*base_dev;
-	struct list_head	cells;
-	const struct nvmem_keepout *keepout;
-	unsigned int		nkeepout;
-	nvmem_reg_read_t	reg_read;
-	nvmem_reg_write_t	reg_write;
-	struct gpio_desc	*wp_gpio;
-	struct nvmem_layout	*layout;
-	void *priv;
-};
+#include "internals.h"
 
 #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
 
@@ -77,9 +55,6 @@ static LIST_HEAD(nvmem_lookup_list);
 
 static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
 
-static DEFINE_SPINLOCK(nvmem_layout_lock);
-static LIST_HEAD(nvmem_layouts);
-
 static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
 			    void *val, size_t bytes)
 {
@@ -324,6 +299,43 @@ static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
 	return nvmem_bin_attr_get_umode(nvmem);
 }
 
+static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry,
+					    const char *id, int index);
+
+static ssize_t nvmem_cell_attr_read(struct file *filp, struct kobject *kobj,
+				    struct bin_attribute *attr, char *buf,
+				    loff_t pos, size_t count)
+{
+	struct nvmem_cell_entry *entry;
+	struct nvmem_cell *cell = NULL;
+	size_t cell_sz, read_len;
+	void *content;
+
+	entry = attr->private;
+	cell = nvmem_create_cell(entry, entry->name, 0);
+	if (IS_ERR(cell))
+		return PTR_ERR(cell);
+
+	if (!cell)
+		return -EINVAL;
+
+	content = nvmem_cell_read(cell, &cell_sz);
+	if (IS_ERR(content)) {
+		read_len = PTR_ERR(content);
+		goto destroy_cell;
+	}
+
+	read_len = min_t(unsigned int, cell_sz - pos, count);
+	memcpy(buf, content + pos, read_len);
+	kfree(content);
+
+destroy_cell:
+	kfree_const(cell->id);
+	kfree(cell);
+
+	return read_len;
+}
+
 /* default read/write permissions */
 static struct bin_attribute bin_attr_rw_nvmem = {
 	.attr	= {
@@ -345,11 +357,21 @@ static const struct attribute_group nvmem_bin_group = {
 	.is_bin_visible = nvmem_bin_attr_is_visible,
 };
 
+/* Cell attributes will be dynamically allocated */
+static struct attribute_group nvmem_cells_group = {
+	.name		= "cells",
+};
+
 static const struct attribute_group *nvmem_dev_groups[] = {
 	&nvmem_bin_group,
 	NULL,
 };
 
+static const struct attribute_group *nvmem_cells_groups[] = {
+	&nvmem_cells_group,
+	NULL,
+};
+
 static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
 	.attr	= {
 		.name	= "eeprom",
@@ -405,6 +427,68 @@ static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 }
 
+static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem)
+{
+	struct bin_attribute **cells_attrs, *attrs;
+	struct nvmem_cell_entry *entry;
+	unsigned int ncells = 0, i = 0;
+	int ret = 0;
+
+	mutex_lock(&nvmem_mutex);
+
+	if (list_empty(&nvmem->cells) || nvmem->sysfs_cells_populated) {
+		nvmem_cells_group.bin_attrs = NULL;
+		goto unlock_mutex;
+	}
+
+	/* Allocate an array of attributes with a sentinel */
+	ncells = list_count_nodes(&nvmem->cells);
+	cells_attrs = devm_kcalloc(&nvmem->dev, ncells + 1,
+				   sizeof(struct bin_attribute *), GFP_KERNEL);
+	if (!cells_attrs) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
+
+	attrs = devm_kcalloc(&nvmem->dev, ncells, sizeof(struct bin_attribute), GFP_KERNEL);
+	if (!attrs) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
+
+	/* Initialize each attribute to take the name and size of the cell */
+	list_for_each_entry(entry, &nvmem->cells, node) {
+		sysfs_bin_attr_init(&attrs[i]);
+		attrs[i].attr.name = devm_kasprintf(&nvmem->dev, GFP_KERNEL,
+						    "%s@%x", entry->name,
+						    entry->offset);
+		attrs[i].attr.mode = 0444;
+		attrs[i].size = entry->bytes;
+		attrs[i].read = &nvmem_cell_attr_read;
+		attrs[i].private = entry;
+		if (!attrs[i].attr.name) {
+			ret = -ENOMEM;
+			goto unlock_mutex;
+		}
+
+		cells_attrs[i] = &attrs[i];
+		i++;
+	}
+
+	nvmem_cells_group.bin_attrs = cells_attrs;
+
+	ret = devm_device_add_groups(&nvmem->dev, nvmem_cells_groups);
+	if (ret)
+		goto unlock_mutex;
+
+	nvmem->sysfs_cells_populated = true;
+
+unlock_mutex:
+	mutex_unlock(&nvmem_mutex);
+
+	return ret;
+}
+
 #else /* CONFIG_NVMEM_SYSFS */
 
 static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
@@ -697,7 +781,6 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
 
 static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np)
 {
-	struct nvmem_layout *layout = nvmem->layout;
 	struct device *dev = &nvmem->dev;
 	struct device_node *child;
 	const __be32 *addr;
@@ -727,8 +810,8 @@ static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_nod
 
 		info.np = of_node_get(child);
 
-		if (layout && layout->fixup_cell_info)
-			layout->fixup_cell_info(nvmem, layout, &info);
+		if (nvmem->fixup_dt_cell_info)
+			nvmem->fixup_dt_cell_info(nvmem, &info);
 
 		ret = nvmem_add_one_cell(nvmem, &info);
 		kfree(info.name);
@@ -763,117 +846,35 @@ static int nvmem_add_cells_from_fixed_layout(struct nvmem_device *nvmem)
 	return err;
 }
 
-int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner)
-{
-	layout->owner = owner;
-
-	spin_lock(&nvmem_layout_lock);
-	list_add(&layout->node, &nvmem_layouts);
-	spin_unlock(&nvmem_layout_lock);
-
-	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_LAYOUT_ADD, layout);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(__nvmem_layout_register);
-
-void nvmem_layout_unregister(struct nvmem_layout *layout)
-{
-	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_LAYOUT_REMOVE, layout);
-
-	spin_lock(&nvmem_layout_lock);
-	list_del(&layout->node);
-	spin_unlock(&nvmem_layout_lock);
-}
-EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
-
-static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem)
+int nvmem_layout_register(struct nvmem_layout *layout)
 {
-	struct device_node *layout_np;
-	struct nvmem_layout *l, *layout = ERR_PTR(-EPROBE_DEFER);
-
-	layout_np = of_nvmem_layout_get_container(nvmem);
-	if (!layout_np)
-		return NULL;
-
-	/* Fixed layouts don't have a matching driver */
-	if (of_device_is_compatible(layout_np, "fixed-layout")) {
-		of_node_put(layout_np);
-		return NULL;
-	}
-
-	/*
-	 * In case the nvmem device was built-in while the layout was built as a
-	 * module, we shall manually request the layout driver loading otherwise
-	 * we'll never have any match.
-	 */
-	of_request_module(layout_np);
-
-	spin_lock(&nvmem_layout_lock);
-
-	list_for_each_entry(l, &nvmem_layouts, node) {
-		if (of_match_node(l->of_match_table, layout_np)) {
-			if (try_module_get(l->owner))
-				layout = l;
-
-			break;
-		}
-	}
-
-	spin_unlock(&nvmem_layout_lock);
-	of_node_put(layout_np);
-
-	return layout;
-}
+	int ret;
 
-static void nvmem_layout_put(struct nvmem_layout *layout)
-{
-	if (layout)
-		module_put(layout->owner);
-}
+	if (!layout->add_cells)
+		return -EINVAL;
 
-static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem)
-{
-	struct nvmem_layout *layout = nvmem->layout;
-	int ret;
+	/* Populate the cells */
+	ret = layout->add_cells(layout);
+	if (ret)
+		return ret;
 
-	if (layout && layout->add_cells) {
-		ret = layout->add_cells(&nvmem->dev, nvmem, layout);
-		if (ret)
-			return ret;
+#ifdef CONFIG_NVMEM_SYSFS
+	ret = nvmem_populate_sysfs_cells(layout->nvmem);
+	if (ret) {
+		nvmem_device_remove_all_cells(layout->nvmem);
+		return ret;
 	}
+#endif
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(nvmem_layout_register);
 
-#if IS_ENABLED(CONFIG_OF)
-/**
- * of_nvmem_layout_get_container() - Get OF node to layout container.
- *
- * @nvmem: nvmem device.
- *
- * Return: a node pointer with refcount incremented or NULL if no
- * container exists. Use of_node_put() on it when done.
- */
-struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
-{
-	return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
-}
-EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
-#endif
-
-const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
-					struct nvmem_layout *layout)
+void nvmem_layout_unregister(struct nvmem_layout *layout)
 {
-	struct device_node __maybe_unused *layout_np;
-	const struct of_device_id *match;
-
-	layout_np = of_nvmem_layout_get_container(nvmem);
-	match = of_match_node(layout->of_match_table, layout_np);
-
-	return match ? match->data : NULL;
+	/* Keep the API even with an empty stub in case we need it later */
 }
-EXPORT_SYMBOL_GPL(nvmem_layout_get_match_data);
+EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
 
 /**
  * nvmem_register() - Register a nvmem device for given nvmem_config.
@@ -925,6 +926,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	kref_init(&nvmem->refcnt);
 	INIT_LIST_HEAD(&nvmem->cells);
+	nvmem->fixup_dt_cell_info = config->fixup_dt_cell_info;
 
 	nvmem->owner = config->owner;
 	if (!nvmem->owner && config->dev->driver)
@@ -980,19 +982,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 			goto err_put_device;
 	}
 
-	/*
-	 * If the driver supplied a layout by config->layout, the module
-	 * pointer will be NULL and nvmem_layout_put() will be a noop.
-	 */
-	nvmem->layout = config->layout ?: nvmem_layout_get(nvmem);
-	if (IS_ERR(nvmem->layout)) {
-		rval = PTR_ERR(nvmem->layout);
-		nvmem->layout = NULL;
-
-		if (rval == -EPROBE_DEFER)
-			goto err_teardown_compat;
-	}
-
 	if (config->cells) {
 		rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
 		if (rval)
@@ -1013,24 +1002,34 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (rval)
 		goto err_remove_cells;
 
-	rval = nvmem_add_cells_from_layout(nvmem);
-	if (rval)
-		goto err_remove_cells;
-
 	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
 
 	rval = device_add(&nvmem->dev);
 	if (rval)
 		goto err_remove_cells;
 
+	rval = nvmem_populate_layout(nvmem);
+	if (rval)
+		goto err_remove_dev;
+
+#ifdef CONFIG_NVMEM_SYSFS
+	rval = nvmem_populate_sysfs_cells(nvmem);
+	if (rval)
+		goto err_destroy_layout;
+#endif
+
 	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
 
 	return nvmem;
 
+#ifdef CONFIG_NVMEM_SYSFS
+err_destroy_layout:
+	nvmem_destroy_layout(nvmem);
+#endif
+err_remove_dev:
+	device_del(&nvmem->dev);
 err_remove_cells:
 	nvmem_device_remove_all_cells(nvmem);
-	nvmem_layout_put(nvmem->layout);
-err_teardown_compat:
 	if (config->compat)
 		nvmem_sysfs_remove_compat(nvmem, config);
 err_put_device:
@@ -1052,7 +1051,7 @@ static void nvmem_device_release(struct kref *kref)
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 
 	nvmem_device_remove_all_cells(nvmem);
-	nvmem_layout_put(nvmem->layout);
+	nvmem_destroy_layout(nvmem);
 	device_unregister(&nvmem->dev);
 }
 
@@ -1354,6 +1353,12 @@ nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
 	return cell;
 }
 
+static void nvmem_layout_module_put(struct nvmem_device *nvmem)
+{
+	if (nvmem->layout && nvmem->layout->dev.driver)
+		module_put(nvmem->layout->dev.driver->owner);
+}
+
 #if IS_ENABLED(CONFIG_OF)
 static struct nvmem_cell_entry *
 nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np)
@@ -1372,6 +1377,18 @@ nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np
 	return cell;
 }
 
+static int nvmem_layout_module_get_optional(struct nvmem_device *nvmem)
+{
+	if (!nvmem->layout)
+		return 0;
+
+	if (!nvmem->layout->dev.driver ||
+	    !try_module_get(nvmem->layout->dev.driver->owner))
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
 /**
  * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
  *
@@ -1434,16 +1451,29 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
 		return ERR_CAST(nvmem);
 	}
 
+	ret = nvmem_layout_module_get_optional(nvmem);
+	if (ret) {
+		of_node_put(cell_np);
+		__nvmem_device_put(nvmem);
+		return ERR_PTR(ret);
+	}
+
 	cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np);
 	of_node_put(cell_np);
 	if (!cell_entry) {
 		__nvmem_device_put(nvmem);
-		return ERR_PTR(-ENOENT);
+		nvmem_layout_module_put(nvmem);
+		if (nvmem->layout)
+			return ERR_PTR(-EPROBE_DEFER);
+		else
+			return ERR_PTR(-ENOENT);
 	}
 
 	cell = nvmem_create_cell(cell_entry, id, cell_index);
-	if (IS_ERR(cell))
+	if (IS_ERR(cell)) {
 		__nvmem_device_put(nvmem);
+		nvmem_layout_module_put(nvmem);
+	}
 
 	return cell;
 }
@@ -1557,6 +1587,7 @@ void nvmem_cell_put(struct nvmem_cell *cell)
 
 	kfree(cell);
 	__nvmem_device_put(nvmem);
+	nvmem_layout_module_put(nvmem);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_put);
 
@@ -2132,13 +2163,37 @@ const char *nvmem_dev_name(struct nvmem_device *nvmem)
 }
 EXPORT_SYMBOL_GPL(nvmem_dev_name);
 
+/**
+ * nvmem_dev_size() - Get the size of a given nvmem device.
+ *
+ * @nvmem: nvmem device.
+ *
+ * Return: size of the nvmem device.
+ */
+size_t nvmem_dev_size(struct nvmem_device *nvmem)
+{
+	return nvmem->size;
+}
+EXPORT_SYMBOL_GPL(nvmem_dev_size);
+
 static int __init nvmem_init(void)
 {
-	return bus_register(&nvmem_bus_type);
+	int ret;
+
+	ret = bus_register(&nvmem_bus_type);
+	if (ret)
+		return ret;
+
+	ret = nvmem_layout_bus_register();
+	if (ret)
+		bus_unregister(&nvmem_bus_type);
+
+	return ret;
 }
 
 static void __exit nvmem_exit(void)
 {
+	nvmem_layout_bus_unregister();
 	bus_unregister(&nvmem_bus_type);
 }