diff options
| -rw-r--r-- | drivers/nvmem/core.c | 84 | ||||
| -rw-r--r-- | include/linux/nvmem-provider.h | 4 |
2 files changed, 79 insertions, 9 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index b03690bc8f09..0de3d878c439 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -38,8 +38,13 @@ struct nvmem_device { int users; size_t size; bool read_only; + int flags; + struct bin_attribute eeprom; + struct device *base_dev; }; +#define FLAG_COMPAT BIT(0) + struct nvmem_cell { const char *name; int offset; @@ -56,16 +61,26 @@ static DEFINE_IDA(nvmem_ida); static LIST_HEAD(nvmem_cells); static DEFINE_MUTEX(nvmem_cells_mutex); +#ifdef CONFIG_DEBUG_LOCK_ALLOC +static struct lock_class_key eeprom_lock_key; +#endif + #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) 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 = container_of(kobj, struct device, kobj); - struct nvmem_device *nvmem = to_nvmem_device(dev); + 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; @@ -90,10 +105,16 @@ 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 = container_of(kobj, struct device, kobj); - struct nvmem_device *nvmem = to_nvmem_device(dev); + 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 0; @@ -349,6 +370,43 @@ err: return rval; } +/* + * 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_setup_compat(struct nvmem_device *nvmem, + const struct nvmem_config *config) +{ + int rval; + + if (!config->base_dev) + return -EINVAL; + + if (nvmem->read_only) + nvmem->eeprom = bin_attr_ro_root_nvmem; + else + nvmem->eeprom = bin_attr_rw_root_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; +} + /** * nvmem_register() - Register a nvmem device for given nvmem_config. * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem @@ -416,16 +474,23 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); rval = device_add(&nvmem->dev); - if (rval) { - ida_simple_remove(&nvmem_ida, nvmem->id); - kfree(nvmem); - return ERR_PTR(rval); + if (rval) + goto out; + + if (config->compat) { + rval = nvmem_setup_compat(nvmem, config); + if (rval) + goto out; } if (config->cells) nvmem_add_cells(nvmem, config); return nvmem; +out: + ida_simple_remove(&nvmem_ida, nvmem->id); + kfree(nvmem); + return ERR_PTR(rval); } EXPORT_SYMBOL_GPL(nvmem_register); @@ -445,6 +510,9 @@ int nvmem_unregister(struct nvmem_device *nvmem) } mutex_unlock(&nvmem_mutex); + if (nvmem->flags & FLAG_COMPAT) + device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); + nvmem_device_remove_all_cells(nvmem); device_del(&nvmem->dev); diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index d24fefa0c11d..a4fcc90b0f20 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -24,6 +24,9 @@ struct nvmem_config { int ncells; bool read_only; bool root_only; + /* To be only used by old driver/misc/eeprom drivers */ + bool compat; + struct device *base_dev; }; #if IS_ENABLED(CONFIG_NVMEM) @@ -44,5 +47,4 @@ static inline int nvmem_unregister(struct nvmem_device *nvmem) } #endif /* CONFIG_NVMEM */ - #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ |