1 files changed, 320 insertions, 45 deletions

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index ef326f243f36..05c6ae4b0b97 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -18,7 +18,31 @@
 #include <linux/gpio/consumer.h>
 #include <linux/of.h>
 #include <linux/slab.h>
-#include "nvmem.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;
+	nvmem_reg_read_t	reg_read;
+	nvmem_reg_write_t	reg_write;
+	struct gpio_desc	*wp_gpio;
+	void *priv;
+};
+
+#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
+
+#define FLAG_COMPAT		BIT(0)
 
 struct nvmem_cell {
 	const char		*name;
@@ -42,6 +66,250 @@ static LIST_HEAD(nvmem_lookup_list);
 
 static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
 
+#ifdef CONFIG_NVMEM_SYSFS
+static const char * const nvmem_type_str[] = {
+	[NVMEM_TYPE_UNKNOWN] = "Unknown",
+	[NVMEM_TYPE_EEPROM] = "EEPROM",
+	[NVMEM_TYPE_OTP] = "OTP",
+	[NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
+};
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key eeprom_lock_key;
+#endif
+
+static ssize_t type_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+
+	return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]);
+}
+
+static DEVICE_ATTR_RO(type);
+
+static struct attribute *nvmem_attrs[] = {
+	&dev_attr_type.attr,
+	NULL,
+};
+
+static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *attr, char *buf,
+				   loff_t pos, size_t count)
+{
+	struct device *dev;
+	struct nvmem_device *nvmem;
+	int rc;
+
+	if (attr->private)
+		dev = attr->private;
+	else
+		dev = container_of(kobj, struct device, kobj);
+	nvmem = to_nvmem_device(dev);
+
+	/* Stop the user from reading */
+	if (pos >= nvmem->size)
+		return 0;
+
+	if (count < nvmem->word_size)
+		return -EINVAL;
+
+	if (pos + count > nvmem->size)
+		count = nvmem->size - pos;
+
+	count = round_down(count, nvmem->word_size);
+
+	if (!nvmem->reg_read)
+		return -EPERM;
+
+	rc = nvmem->reg_read(nvmem->priv, pos, buf, count);
+
+	if (rc)
+		return rc;
+
+	return count;
+}
+
+static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
+				    struct bin_attribute *attr, char *buf,
+				    loff_t pos, size_t count)
+{
+	struct device *dev;
+	struct nvmem_device *nvmem;
+	int rc;
+
+	if (attr->private)
+		dev = attr->private;
+	else
+		dev = container_of(kobj, struct device, kobj);
+	nvmem = to_nvmem_device(dev);
+
+	/* Stop the user from writing */
+	if (pos >= nvmem->size)
+		return -EFBIG;
+
+	if (count < nvmem->word_size)
+		return -EINVAL;
+
+	if (pos + count > nvmem->size)
+		count = nvmem->size - pos;
+
+	count = round_down(count, nvmem->word_size);
+
+	if (!nvmem->reg_write)
+		return -EPERM;
+
+	rc = nvmem->reg_write(nvmem->priv, pos, buf, count);
+
+	if (rc)
+		return rc;
+
+	return count;
+}
+
+static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
+					 struct bin_attribute *attr, int i)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+	umode_t mode = 0400;
+
+	if (!nvmem->root_only)
+		mode |= 0044;
+
+	if (!nvmem->read_only)
+		mode |= 0200;
+
+	if (!nvmem->reg_write)
+		mode &= ~0200;
+
+	if (!nvmem->reg_read)
+		mode &= ~0444;
+
+	return mode;
+}
+
+/* default read/write permissions */
+static struct bin_attribute bin_attr_rw_nvmem = {
+	.attr	= {
+		.name	= "nvmem",
+		.mode	= 0644,
+	},
+	.read	= bin_attr_nvmem_read,
+	.write	= bin_attr_nvmem_write,
+};
+
+static struct bin_attribute *nvmem_bin_attributes[] = {
+	&bin_attr_rw_nvmem,
+	NULL,
+};
+
+static const struct attribute_group nvmem_bin_group = {
+	.bin_attrs	= nvmem_bin_attributes,
+	.attrs		= nvmem_attrs,
+	.is_bin_visible = nvmem_bin_attr_is_visible,
+};
+
+static const struct attribute_group *nvmem_dev_groups[] = {
+	&nvmem_bin_group,
+	NULL,
+};
+
+/* read only permission */
+static struct bin_attribute bin_attr_ro_nvmem = {
+	.attr	= {
+		.name	= "nvmem",
+		.mode	= 0444,
+	},
+	.read	= bin_attr_nvmem_read,
+};
+
+/* default read/write permissions, root only */
+static struct bin_attribute bin_attr_rw_root_nvmem = {
+	.attr	= {
+		.name	= "nvmem",
+		.mode	= 0600,
+	},
+	.read	= bin_attr_nvmem_read,
+	.write	= bin_attr_nvmem_write,
+};
+
+/* read only permission, root only */
+static struct bin_attribute bin_attr_ro_root_nvmem = {
+	.attr	= {
+		.name	= "nvmem",
+		.mode	= 0400,
+	},
+	.read	= bin_attr_nvmem_read,
+};
+
+/*
+ * nvmem_setup_compat() - Create an additional binary entry in
+ * drivers sys directory, to be backwards compatible with the older
+ * drivers/misc/eeprom drivers.
+ */
+static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
+				    const struct nvmem_config *config)
+{
+	int rval;
+
+	if (!config->compat)
+		return 0;
+
+	if (!config->base_dev)
+		return -EINVAL;
+
+	if (nvmem->read_only) {
+		if (config->root_only)
+			nvmem->eeprom = bin_attr_ro_root_nvmem;
+		else
+			nvmem->eeprom = bin_attr_ro_nvmem;
+	} else {
+		if (config->root_only)
+			nvmem->eeprom = bin_attr_rw_root_nvmem;
+		else
+			nvmem->eeprom = bin_attr_rw_nvmem;
+	}
+	nvmem->eeprom.attr.name = "eeprom";
+	nvmem->eeprom.size = nvmem->size;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	nvmem->eeprom.attr.key = &eeprom_lock_key;
+#endif
+	nvmem->eeprom.private = &nvmem->dev;
+	nvmem->base_dev = config->base_dev;
+
+	rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
+	if (rval) {
+		dev_err(&nvmem->dev,
+			"Failed to create eeprom binary file %d\n", rval);
+		return rval;
+	}
+
+	nvmem->flags |= FLAG_COMPAT;
+
+	return 0;
+}
+
+static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
+			      const struct nvmem_config *config)
+{
+	if (config->compat)
+		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
+}
+
+#else /* CONFIG_NVMEM_SYSFS */
+
+static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
+				    const struct nvmem_config *config)
+{
+	return -ENOSYS;
+}
+static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
+				      const struct nvmem_config *config)
+{
+}
+
+#endif /* CONFIG_NVMEM_SYSFS */
 
 static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
 			  void *val, size_t bytes)
@@ -72,6 +340,7 @@ static void nvmem_release(struct device *dev)
 	struct nvmem_device *nvmem = to_nvmem_device(dev);
 
 	ida_simple_remove(&nvmem_ida, nvmem->id);
+	gpiod_put(nvmem->wp_gpio);
 	kfree(nvmem);
 }
 
@@ -338,6 +607,9 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (!config->dev)
 		return ERR_PTR(-EINVAL);
 
+	if (!config->reg_read && !config->reg_write)
+		return ERR_PTR(-EINVAL);
+
 	nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
 	if (!nvmem)
 		return ERR_PTR(-ENOMEM);
@@ -347,14 +619,18 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 		kfree(nvmem);
 		return ERR_PTR(rval);
 	}
+
 	if (config->wp_gpio)
 		nvmem->wp_gpio = config->wp_gpio;
 	else
 		nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
 						    GPIOD_OUT_HIGH);
-	if (IS_ERR(nvmem->wp_gpio))
-		return ERR_CAST(nvmem->wp_gpio);
-
+	if (IS_ERR(nvmem->wp_gpio)) {
+		ida_simple_remove(&nvmem_ida, nvmem->id);
+		rval = PTR_ERR(nvmem->wp_gpio);
+		kfree(nvmem);
+		return ERR_PTR(rval);
+	}
 
 	kref_init(&nvmem->refcnt);
 	INIT_LIST_HEAD(&nvmem->cells);
@@ -369,6 +645,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	nvmem->dev.type = &nvmem_provider_type;
 	nvmem->dev.bus = &nvmem_bus_type;
 	nvmem->dev.parent = config->dev;
+	nvmem->root_only = config->root_only;
 	nvmem->priv = config->priv;
 	nvmem->type = config->type;
 	nvmem->reg_read = config->reg_read;
@@ -387,13 +664,13 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	nvmem->read_only = device_property_present(config->dev, "read-only") ||
 			   config->read_only || !nvmem->reg_write;
 
-	nvmem->dev.groups = nvmem_sysfs_get_groups(nvmem, config);
-
-	device_initialize(&nvmem->dev);
+#ifdef CONFIG_NVMEM_SYSFS
+	nvmem->dev.groups = nvmem_dev_groups;
+#endif
 
 	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
 
-	rval = device_add(&nvmem->dev);
+	rval = device_register(&nvmem->dev);
 	if (rval)
 		goto err_put_device;
 
@@ -447,8 +724,7 @@ static void nvmem_device_release(struct kref *kref)
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 
 	nvmem_device_remove_all_cells(nvmem);
-	device_del(&nvmem->dev);
-	put_device(&nvmem->dev);
+	device_unregister(&nvmem->dev);
 }
 
 /**
@@ -1088,16 +1364,8 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_write);
 
-/**
- * nvmem_cell_read_u16() - Read a cell value as an u16
- *
- * @dev: Device that requests the nvmem cell.
- * @cell_id: Name of nvmem cell to read.
- * @val: pointer to output value.
- *
- * Return: 0 on success or negative errno.
- */
-int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
+static int nvmem_cell_read_common(struct device *dev, const char *cell_id,
+				  void *val, size_t count)
 {
 	struct nvmem_cell *cell;
 	void *buf;
@@ -1112,17 +1380,31 @@ int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
 		nvmem_cell_put(cell);
 		return PTR_ERR(buf);
 	}
-	if (len != sizeof(*val)) {
+	if (len != count) {
 		kfree(buf);
 		nvmem_cell_put(cell);
 		return -EINVAL;
 	}
-	memcpy(val, buf, sizeof(*val));
+	memcpy(val, buf, count);
 	kfree(buf);
 	nvmem_cell_put(cell);
 
 	return 0;
 }
+
+/**
+ * nvmem_cell_read_u16() - Read a cell value as an u16
+ *
+ * @dev: Device that requests the nvmem cell.
+ * @cell_id: Name of nvmem cell to read.
+ * @val: pointer to output value.
+ *
+ * Return: 0 on success or negative errno.
+ */
+int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val)
+{
+	return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
+}
 EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
 
 /**
@@ -1136,33 +1418,26 @@ EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);
  */
 int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val)
 {
-	struct nvmem_cell *cell;
-	void *buf;
-	size_t len;
-
-	cell = nvmem_cell_get(dev, cell_id);
-	if (IS_ERR(cell))
-		return PTR_ERR(cell);
-
-	buf = nvmem_cell_read(cell, &len);
-	if (IS_ERR(buf)) {
-		nvmem_cell_put(cell);
-		return PTR_ERR(buf);
-	}
-	if (len != sizeof(*val)) {
-		kfree(buf);
-		nvmem_cell_put(cell);
-		return -EINVAL;
-	}
-	memcpy(val, buf, sizeof(*val));
-
-	kfree(buf);
-	nvmem_cell_put(cell);
-	return 0;
+	return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_read_u32);
 
 /**
+ * nvmem_cell_read_u64() - Read a cell value as an u64
+ *
+ * @dev: Device that requests the nvmem cell.
+ * @cell_id: Name of nvmem cell to read.
+ * @val: pointer to output value.
+ *
+ * Return: 0 on success or negative errno.
+ */
+int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val)
+{
+	return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_read_u64);
+
+/**
  * nvmem_device_cell_read() - Read a given nvmem device and cell
  *
  * @nvmem: nvmem device to read from.