diff options
Diffstat (limited to 'drivers/nvmem/core.c')
-rw-r--r-- | drivers/nvmem/core.c | 360 |
1 files changed, 208 insertions, 152 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 608b352a7d..eb357ac2e5 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 +427,69 @@ 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,%x", entry->name, + entry->offset, + entry->bit_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 +782,6 @@ 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 +811,8 @@ 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 +847,35 @@ 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 +927,7 @@ 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 +983,6 @@ 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 +1003,34 @@ 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 +1052,7 @@ 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 +1354,12 @@ 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 +1378,18 @@ 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 +1452,29 @@ 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 +1588,7 @@ 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 +2164,37 @@ 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); } |