| /* |
| * nvmem framework core. |
| * |
| * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> |
| * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 and |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/export.h> |
| #include <linux/fs.h> |
| #include <linux/idr.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/nvmem-consumer.h> |
| #include <linux/nvmem-provider.h> |
| #include <linux/of.h> |
| #include <linux/slab.h> |
| |
| struct nvmem_device { |
| const char *name; |
| struct module *owner; |
| struct device dev; |
| int stride; |
| int word_size; |
| int id; |
| int users; |
| size_t size; |
| bool read_only; |
| int flags; |
| struct bin_attribute eeprom; |
| struct device *base_dev; |
| nvmem_reg_read_t reg_read; |
| nvmem_reg_write_t reg_write; |
| void *priv; |
| }; |
| |
| #define FLAG_COMPAT BIT(0) |
| |
| struct nvmem_cell { |
| const char *name; |
| int offset; |
| int bytes; |
| int bit_offset; |
| int nbits; |
| struct nvmem_device *nvmem; |
| struct list_head node; |
| }; |
| |
| static DEFINE_MUTEX(nvmem_mutex); |
| 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 int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
| void *val, size_t bytes) |
| { |
| if (nvmem->reg_read) |
| return nvmem->reg_read(nvmem->priv, offset, val, bytes); |
| |
| return -EINVAL; |
| } |
| |
| static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, |
| void *val, size_t bytes) |
| { |
| if (nvmem->reg_write) |
| return nvmem->reg_write(nvmem->priv, offset, val, bytes); |
| |
| return -EINVAL; |
| } |
| |
| 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); |
| |
| rc = nvmem_reg_read(nvmem, 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); |
| |
| rc = nvmem_reg_write(nvmem, pos, buf, count); |
| |
| if (rc) |
| return rc; |
| |
| return count; |
| } |
| |
| /* default read/write permissions */ |
| static struct bin_attribute bin_attr_rw_nvmem = { |
| .attr = { |
| .name = "nvmem", |
| .mode = S_IWUSR | S_IRUGO, |
| }, |
| .read = bin_attr_nvmem_read, |
| .write = bin_attr_nvmem_write, |
| }; |
| |
| static struct bin_attribute *nvmem_bin_rw_attributes[] = { |
| &bin_attr_rw_nvmem, |
| NULL, |
| }; |
| |
| static const struct attribute_group nvmem_bin_rw_group = { |
| .bin_attrs = nvmem_bin_rw_attributes, |
| }; |
| |
| static const struct attribute_group *nvmem_rw_dev_groups[] = { |
| &nvmem_bin_rw_group, |
| NULL, |
| }; |
| |
| /* read only permission */ |
| static struct bin_attribute bin_attr_ro_nvmem = { |
| .attr = { |
| .name = "nvmem", |
| .mode = S_IRUGO, |
| }, |
| .read = bin_attr_nvmem_read, |
| }; |
| |
| static struct bin_attribute *nvmem_bin_ro_attributes[] = { |
| &bin_attr_ro_nvmem, |
| NULL, |
| }; |
| |
| static const struct attribute_group nvmem_bin_ro_group = { |
| .bin_attrs = nvmem_bin_ro_attributes, |
| }; |
| |
| static const struct attribute_group *nvmem_ro_dev_groups[] = { |
| &nvmem_bin_ro_group, |
| NULL, |
| }; |
| |
| /* default read/write permissions, root only */ |
| static struct bin_attribute bin_attr_rw_root_nvmem = { |
| .attr = { |
| .name = "nvmem", |
| .mode = S_IWUSR | S_IRUSR, |
| }, |
| .read = bin_attr_nvmem_read, |
| .write = bin_attr_nvmem_write, |
| }; |
| |
| static struct bin_attribute *nvmem_bin_rw_root_attributes[] = { |
| &bin_attr_rw_root_nvmem, |
| NULL, |
| }; |
| |
| static const struct attribute_group nvmem_bin_rw_root_group = { |
| .bin_attrs = nvmem_bin_rw_root_attributes, |
| }; |
| |
| static const struct attribute_group *nvmem_rw_root_dev_groups[] = { |
| &nvmem_bin_rw_root_group, |
| NULL, |
| }; |
| |
| /* read only permission, root only */ |
| static struct bin_attribute bin_attr_ro_root_nvmem = { |
| .attr = { |
| .name = "nvmem", |
| .mode = S_IRUSR, |
| }, |
| .read = bin_attr_nvmem_read, |
| }; |
| |
| static struct bin_attribute *nvmem_bin_ro_root_attributes[] = { |
| &bin_attr_ro_root_nvmem, |
| NULL, |
| }; |
| |
| static const struct attribute_group nvmem_bin_ro_root_group = { |
| .bin_attrs = nvmem_bin_ro_root_attributes, |
| }; |
| |
| static const struct attribute_group *nvmem_ro_root_dev_groups[] = { |
| &nvmem_bin_ro_root_group, |
| NULL, |
| }; |
| |
| static void nvmem_release(struct device *dev) |
| { |
| struct nvmem_device *nvmem = to_nvmem_device(dev); |
| |
| ida_simple_remove(&nvmem_ida, nvmem->id); |
| kfree(nvmem); |
| } |
| |
| static const struct device_type nvmem_provider_type = { |
| .release = nvmem_release, |
| }; |
| |
| static struct bus_type nvmem_bus_type = { |
| .name = "nvmem", |
| }; |
| |
| static int of_nvmem_match(struct device *dev, void *nvmem_np) |
| { |
| return dev->of_node == nvmem_np; |
| } |
| |
| static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) |
| { |
| struct device *d; |
| |
| if (!nvmem_np) |
| return NULL; |
| |
| d = bus_find_device(&nvmem_bus_type, NULL, nvmem_np, of_nvmem_match); |
| |
| if (!d) |
| return NULL; |
| |
| return to_nvmem_device(d); |
| } |
| |
| static struct nvmem_cell *nvmem_find_cell(const char *cell_id) |
| { |
| struct nvmem_cell *p; |
| |
| mutex_lock(&nvmem_cells_mutex); |
| |
| list_for_each_entry(p, &nvmem_cells, node) |
| if (!strcmp(p->name, cell_id)) { |
| mutex_unlock(&nvmem_cells_mutex); |
| return p; |
| } |
| |
| mutex_unlock(&nvmem_cells_mutex); |
| |
| return NULL; |
| } |
| |
| static void nvmem_cell_drop(struct nvmem_cell *cell) |
| { |
| mutex_lock(&nvmem_cells_mutex); |
| list_del(&cell->node); |
| mutex_unlock(&nvmem_cells_mutex); |
| kfree(cell); |
| } |
| |
| static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) |
| { |
| struct nvmem_cell *cell; |
| struct list_head *p, *n; |
| |
| list_for_each_safe(p, n, &nvmem_cells) { |
| cell = list_entry(p, struct nvmem_cell, node); |
| if (cell->nvmem == nvmem) |
| nvmem_cell_drop(cell); |
| } |
| } |
| |
| static void nvmem_cell_add(struct nvmem_cell *cell) |
| { |
| mutex_lock(&nvmem_cells_mutex); |
| list_add_tail(&cell->node, &nvmem_cells); |
| mutex_unlock(&nvmem_cells_mutex); |
| } |
| |
| static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, |
| const struct nvmem_cell_info *info, |
| struct nvmem_cell *cell) |
| { |
| cell->nvmem = nvmem; |
| cell->offset = info->offset; |
| cell->bytes = info->bytes; |
| cell->name = info->name; |
| |
| cell->bit_offset = info->bit_offset; |
| cell->nbits = info->nbits; |
| |
| if (cell->nbits) |
| cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, |
| BITS_PER_BYTE); |
| |
| if (!IS_ALIGNED(cell->offset, nvmem->stride)) { |
| dev_err(&nvmem->dev, |
| "cell %s unaligned to nvmem stride %d\n", |
| cell->name, nvmem->stride); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * nvmem_add_cells() - Add cell information to an nvmem device |
| * |
| * @nvmem: nvmem device to add cells to. |
| * @info: nvmem cell info to add to the device |
| * @ncells: number of cells in info |
| * |
| * Return: 0 or negative error code on failure. |
| */ |
| int nvmem_add_cells(struct nvmem_device *nvmem, |
| const struct nvmem_cell_info *info, |
| int ncells) |
| { |
| struct nvmem_cell **cells; |
| int i, rval; |
| |
| cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL); |
| if (!cells) |
| return -ENOMEM; |
| |
| for (i = 0; i < ncells; i++) { |
| cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); |
| if (!cells[i]) { |
| rval = -ENOMEM; |
| goto err; |
| } |
| |
| rval = nvmem_cell_info_to_nvmem_cell(nvmem, &info[i], cells[i]); |
| if (rval) { |
| kfree(cells[i]); |
| goto err; |
| } |
| |
| nvmem_cell_add(cells[i]); |
| } |
| |
| /* remove tmp array */ |
| kfree(cells); |
| |
| return 0; |
| err: |
| while (i--) |
| nvmem_cell_drop(cells[i]); |
| |
| kfree(cells); |
| |
| return rval; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_add_cells); |
| |
| /* |
| * 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) { |
| 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; |
| } |
| |
| /** |
| * nvmem_register() - Register a nvmem device for given nvmem_config. |
| * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem |
| * |
| * @config: nvmem device configuration with which nvmem device is created. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device |
| * on success. |
| */ |
| |
| struct nvmem_device *nvmem_register(const struct nvmem_config *config) |
| { |
| struct nvmem_device *nvmem; |
| int rval; |
| |
| if (!config->dev) |
| return ERR_PTR(-EINVAL); |
| |
| nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); |
| if (!nvmem) |
| return ERR_PTR(-ENOMEM); |
| |
| rval = ida_simple_get(&nvmem_ida, 0, 0, GFP_KERNEL); |
| if (rval < 0) { |
| kfree(nvmem); |
| return ERR_PTR(rval); |
| } |
| |
| nvmem->id = rval; |
| nvmem->owner = config->owner; |
| if (!nvmem->owner && config->dev->driver) |
| nvmem->owner = config->dev->driver->owner; |
| nvmem->stride = config->stride ?: 1; |
| nvmem->word_size = config->word_size ?: 1; |
| nvmem->size = config->size; |
| nvmem->dev.type = &nvmem_provider_type; |
| nvmem->dev.bus = &nvmem_bus_type; |
| nvmem->dev.parent = config->dev; |
| nvmem->priv = config->priv; |
| nvmem->reg_read = config->reg_read; |
| nvmem->reg_write = config->reg_write; |
| nvmem->dev.of_node = config->dev->of_node; |
| |
| if (config->id == -1 && config->name) { |
| dev_set_name(&nvmem->dev, "%s", config->name); |
| } else { |
| dev_set_name(&nvmem->dev, "%s%d", |
| config->name ? : "nvmem", |
| config->name ? config->id : nvmem->id); |
| } |
| |
| nvmem->read_only = device_property_present(config->dev, "read-only") | |
| config->read_only; |
| |
| if (config->root_only) |
| nvmem->dev.groups = nvmem->read_only ? |
| nvmem_ro_root_dev_groups : |
| nvmem_rw_root_dev_groups; |
| else |
| nvmem->dev.groups = nvmem->read_only ? |
| nvmem_ro_dev_groups : |
| nvmem_rw_dev_groups; |
| |
| device_initialize(&nvmem->dev); |
| |
| dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); |
| |
| rval = device_add(&nvmem->dev); |
| if (rval) |
| goto err_put_device; |
| |
| if (config->compat) { |
| rval = nvmem_setup_compat(nvmem, config); |
| if (rval) |
| goto err_device_del; |
| } |
| |
| if (config->cells) { |
| rval = nvmem_add_cells(nvmem, config->cells, config->ncells); |
| if (rval) |
| goto err_teardown_compat; |
| } |
| |
| return nvmem; |
| |
| err_teardown_compat: |
| if (config->compat) |
| device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); |
| err_device_del: |
| device_del(&nvmem->dev); |
| err_put_device: |
| put_device(&nvmem->dev); |
| |
| return ERR_PTR(rval); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_register); |
| |
| /** |
| * nvmem_unregister() - Unregister previously registered nvmem device |
| * |
| * @nvmem: Pointer to previously registered nvmem device. |
| * |
| * Return: Will be an negative on error or a zero on success. |
| */ |
| int nvmem_unregister(struct nvmem_device *nvmem) |
| { |
| mutex_lock(&nvmem_mutex); |
| if (nvmem->users) { |
| mutex_unlock(&nvmem_mutex); |
| return -EBUSY; |
| } |
| 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); |
| put_device(&nvmem->dev); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_unregister); |
| |
| static void devm_nvmem_release(struct device *dev, void *res) |
| { |
| WARN_ON(nvmem_unregister(*(struct nvmem_device **)res)); |
| } |
| |
| /** |
| * devm_nvmem_register() - Register a managed nvmem device for given |
| * nvmem_config. |
| * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem |
| * |
| * @dev: Device that uses the nvmem device. |
| * @config: nvmem device configuration with which nvmem device is created. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *devm_nvmem_register(struct device *dev, |
| const struct nvmem_config *config) |
| { |
| struct nvmem_device **ptr, *nvmem; |
| |
| ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| nvmem = nvmem_register(config); |
| |
| if (!IS_ERR(nvmem)) { |
| *ptr = nvmem; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return nvmem; |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_register); |
| |
| static int devm_nvmem_match(struct device *dev, void *res, void *data) |
| { |
| struct nvmem_device **r = res; |
| |
| return *r == data; |
| } |
| |
| /** |
| * devm_nvmem_unregister() - Unregister previously registered managed nvmem |
| * device. |
| * |
| * @dev: Device that uses the nvmem device. |
| * @nvmem: Pointer to previously registered nvmem device. |
| * |
| * Return: Will be an negative on error or a zero on success. |
| */ |
| int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) |
| { |
| return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem); |
| } |
| EXPORT_SYMBOL(devm_nvmem_unregister); |
| |
| |
| static struct nvmem_device *__nvmem_device_get(struct device_node *np, |
| struct nvmem_cell **cellp, |
| const char *cell_id) |
| { |
| struct nvmem_device *nvmem = NULL; |
| |
| mutex_lock(&nvmem_mutex); |
| |
| if (np) { |
| nvmem = of_nvmem_find(np); |
| if (!nvmem) { |
| mutex_unlock(&nvmem_mutex); |
| return ERR_PTR(-EPROBE_DEFER); |
| } |
| } else { |
| struct nvmem_cell *cell = nvmem_find_cell(cell_id); |
| |
| if (cell) { |
| nvmem = cell->nvmem; |
| *cellp = cell; |
| } |
| |
| if (!nvmem) { |
| mutex_unlock(&nvmem_mutex); |
| return ERR_PTR(-ENOENT); |
| } |
| } |
| |
| nvmem->users++; |
| mutex_unlock(&nvmem_mutex); |
| |
| if (!try_module_get(nvmem->owner)) { |
| dev_err(&nvmem->dev, |
| "could not increase module refcount for cell %s\n", |
| nvmem->name); |
| |
| mutex_lock(&nvmem_mutex); |
| nvmem->users--; |
| mutex_unlock(&nvmem_mutex); |
| |
| return ERR_PTR(-EINVAL); |
| } |
| |
| return nvmem; |
| } |
| |
| static void __nvmem_device_put(struct nvmem_device *nvmem) |
| { |
| module_put(nvmem->owner); |
| mutex_lock(&nvmem_mutex); |
| nvmem->users--; |
| mutex_unlock(&nvmem_mutex); |
| } |
| |
| static struct nvmem_device *nvmem_find(const char *name) |
| { |
| struct device *d; |
| |
| d = bus_find_device_by_name(&nvmem_bus_type, NULL, name); |
| |
| if (!d) |
| return ERR_PTR(-ENOENT); |
| |
| return to_nvmem_device(d); |
| } |
| |
| #if IS_ENABLED(CONFIG_OF) |
| /** |
| * of_nvmem_device_get() - Get nvmem device from a given id |
| * |
| * @np: Device tree node that uses the nvmem device. |
| * @id: nvmem name from nvmem-names property. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) |
| { |
| |
| struct device_node *nvmem_np; |
| int index; |
| |
| index = of_property_match_string(np, "nvmem-names", id); |
| |
| nvmem_np = of_parse_phandle(np, "nvmem", index); |
| if (!nvmem_np) |
| return ERR_PTR(-EINVAL); |
| |
| return __nvmem_device_get(nvmem_np, NULL, NULL); |
| } |
| EXPORT_SYMBOL_GPL(of_nvmem_device_get); |
| #endif |
| |
| /** |
| * nvmem_device_get() - Get nvmem device from a given id |
| * |
| * @dev: Device that uses the nvmem device. |
| * @dev_name: name of the requested nvmem device. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) |
| { |
| if (dev->of_node) { /* try dt first */ |
| struct nvmem_device *nvmem; |
| |
| nvmem = of_nvmem_device_get(dev->of_node, dev_name); |
| |
| if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) |
| return nvmem; |
| |
| } |
| |
| return nvmem_find(dev_name); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_get); |
| |
| static int devm_nvmem_device_match(struct device *dev, void *res, void *data) |
| { |
| struct nvmem_device **nvmem = res; |
| |
| if (WARN_ON(!nvmem || !*nvmem)) |
| return 0; |
| |
| return *nvmem == data; |
| } |
| |
| static void devm_nvmem_device_release(struct device *dev, void *res) |
| { |
| nvmem_device_put(*(struct nvmem_device **)res); |
| } |
| |
| /** |
| * devm_nvmem_device_put() - put alredy got nvmem device |
| * |
| * @dev: Device that uses the nvmem device. |
| * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
| * that needs to be released. |
| */ |
| void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) |
| { |
| int ret; |
| |
| ret = devres_release(dev, devm_nvmem_device_release, |
| devm_nvmem_device_match, nvmem); |
| |
| WARN_ON(ret); |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_device_put); |
| |
| /** |
| * nvmem_device_put() - put alredy got nvmem device |
| * |
| * @nvmem: pointer to nvmem device that needs to be released. |
| */ |
| void nvmem_device_put(struct nvmem_device *nvmem) |
| { |
| __nvmem_device_put(nvmem); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_put); |
| |
| /** |
| * devm_nvmem_device_get() - Get nvmem cell of device form a given id |
| * |
| * @dev: Device that requests the nvmem device. |
| * @id: name id for the requested nvmem device. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell |
| * on success. The nvmem_cell will be freed by the automatically once the |
| * device is freed. |
| */ |
| struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) |
| { |
| struct nvmem_device **ptr, *nvmem; |
| |
| ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| nvmem = nvmem_device_get(dev, id); |
| if (!IS_ERR(nvmem)) { |
| *ptr = nvmem; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return nvmem; |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_device_get); |
| |
| static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) |
| { |
| struct nvmem_cell *cell = NULL; |
| struct nvmem_device *nvmem; |
| |
| nvmem = __nvmem_device_get(NULL, &cell, cell_id); |
| if (IS_ERR(nvmem)) |
| return ERR_CAST(nvmem); |
| |
| return cell; |
| } |
| |
| #if IS_ENABLED(CONFIG_OF) |
| /** |
| * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id |
| * |
| * @np: Device tree node that uses the nvmem cell. |
| * @name: nvmem cell name from nvmem-cell-names property, or NULL |
| * for the cell at index 0 (the lone cell with no accompanying |
| * nvmem-cell-names property). |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer |
| * to a struct nvmem_cell. The nvmem_cell will be freed by the |
| * nvmem_cell_put(). |
| */ |
| struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, |
| const char *name) |
| { |
| struct device_node *cell_np, *nvmem_np; |
| struct nvmem_cell *cell; |
| struct nvmem_device *nvmem; |
| const __be32 *addr; |
| int rval, len; |
| int index = 0; |
| |
| /* if cell name exists, find index to the name */ |
| if (name) |
| index = of_property_match_string(np, "nvmem-cell-names", name); |
| |
| cell_np = of_parse_phandle(np, "nvmem-cells", index); |
| if (!cell_np) |
| return ERR_PTR(-EINVAL); |
| |
| nvmem_np = of_get_next_parent(cell_np); |
| if (!nvmem_np) |
| return ERR_PTR(-EINVAL); |
| |
| nvmem = __nvmem_device_get(nvmem_np, NULL, NULL); |
| of_node_put(nvmem_np); |
| if (IS_ERR(nvmem)) |
| return ERR_CAST(nvmem); |
| |
| addr = of_get_property(cell_np, "reg", &len); |
| if (!addr || (len < 2 * sizeof(u32))) { |
| dev_err(&nvmem->dev, "nvmem: invalid reg on %pOF\n", |
| cell_np); |
| rval = -EINVAL; |
| goto err_mem; |
| } |
| |
| cell = kzalloc(sizeof(*cell), GFP_KERNEL); |
| if (!cell) { |
| rval = -ENOMEM; |
| goto err_mem; |
| } |
| |
| cell->nvmem = nvmem; |
| cell->offset = be32_to_cpup(addr++); |
| cell->bytes = be32_to_cpup(addr); |
| cell->name = cell_np->name; |
| |
| addr = of_get_property(cell_np, "bits", &len); |
| if (addr && len == (2 * sizeof(u32))) { |
| cell->bit_offset = be32_to_cpup(addr++); |
| cell->nbits = be32_to_cpup(addr); |
| } |
| |
| if (cell->nbits) |
| cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, |
| BITS_PER_BYTE); |
| |
| if (!IS_ALIGNED(cell->offset, nvmem->stride)) { |
| dev_err(&nvmem->dev, |
| "cell %s unaligned to nvmem stride %d\n", |
| cell->name, nvmem->stride); |
| rval = -EINVAL; |
| goto err_sanity; |
| } |
| |
| nvmem_cell_add(cell); |
| |
| return cell; |
| |
| err_sanity: |
| kfree(cell); |
| |
| err_mem: |
| __nvmem_device_put(nvmem); |
| |
| return ERR_PTR(rval); |
| } |
| EXPORT_SYMBOL_GPL(of_nvmem_cell_get); |
| #endif |
| |
| /** |
| * nvmem_cell_get() - Get nvmem cell of device form a given cell name |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: nvmem cell name to get. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer |
| * to a struct nvmem_cell. The nvmem_cell will be freed by the |
| * nvmem_cell_put(). |
| */ |
| struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id) |
| { |
| struct nvmem_cell *cell; |
| |
| if (dev->of_node) { /* try dt first */ |
| cell = of_nvmem_cell_get(dev->of_node, cell_id); |
| if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) |
| return cell; |
| } |
| |
| /* NULL cell_id only allowed for device tree; invalid otherwise */ |
| if (!cell_id) |
| return ERR_PTR(-EINVAL); |
| |
| return nvmem_cell_get_from_list(cell_id); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_get); |
| |
| static void devm_nvmem_cell_release(struct device *dev, void *res) |
| { |
| nvmem_cell_put(*(struct nvmem_cell **)res); |
| } |
| |
| /** |
| * devm_nvmem_cell_get() - Get nvmem cell of device form a given id |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @id: nvmem cell name id to get. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer |
| * to a struct nvmem_cell. The nvmem_cell will be freed by the |
| * automatically once the device is freed. |
| */ |
| struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) |
| { |
| struct nvmem_cell **ptr, *cell; |
| |
| ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| cell = nvmem_cell_get(dev, id); |
| if (!IS_ERR(cell)) { |
| *ptr = cell; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return cell; |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); |
| |
| static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) |
| { |
| struct nvmem_cell **c = res; |
| |
| if (WARN_ON(!c || !*c)) |
| return 0; |
| |
| return *c == data; |
| } |
| |
| /** |
| * devm_nvmem_cell_put() - Release previously allocated nvmem cell |
| * from devm_nvmem_cell_get. |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). |
| */ |
| void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) |
| { |
| int ret; |
| |
| ret = devres_release(dev, devm_nvmem_cell_release, |
| devm_nvmem_cell_match, cell); |
| |
| WARN_ON(ret); |
| } |
| EXPORT_SYMBOL(devm_nvmem_cell_put); |
| |
| /** |
| * nvmem_cell_put() - Release previously allocated nvmem cell. |
| * |
| * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
| */ |
| void nvmem_cell_put(struct nvmem_cell *cell) |
| { |
| struct nvmem_device *nvmem = cell->nvmem; |
| |
| __nvmem_device_put(nvmem); |
| nvmem_cell_drop(cell); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_put); |
| |
| static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) |
| { |
| u8 *p, *b; |
| int i, extra, bit_offset = cell->bit_offset; |
| |
| p = b = buf; |
| if (bit_offset) { |
| /* First shift */ |
| *b++ >>= bit_offset; |
| |
| /* setup rest of the bytes if any */ |
| for (i = 1; i < cell->bytes; i++) { |
| /* Get bits from next byte and shift them towards msb */ |
| *p |= *b << (BITS_PER_BYTE - bit_offset); |
| |
| p = b; |
| *b++ >>= bit_offset; |
| } |
| } else { |
| /* point to the msb */ |
| p += cell->bytes - 1; |
| } |
| |
| /* result fits in less bytes */ |
| extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE); |
| while (--extra >= 0) |
| *p-- = 0; |
| |
| /* clear msb bits if any leftover in the last byte */ |
| if (cell->nbits % BITS_PER_BYTE) |
| *p &= GENMASK((cell->nbits % BITS_PER_BYTE) - 1, 0); |
| } |
| |
| static int __nvmem_cell_read(struct nvmem_device *nvmem, |
| struct nvmem_cell *cell, |
| void *buf, size_t *len) |
| { |
| int rc; |
| |
| rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); |
| |
| if (rc) |
| return rc; |
| |
| /* shift bits in-place */ |
| if (cell->bit_offset || cell->nbits) |
| nvmem_shift_read_buffer_in_place(cell, buf); |
| |
| if (len) |
| *len = cell->bytes; |
| |
| return 0; |
| } |
| |
| /** |
| * nvmem_cell_read() - Read a given nvmem cell |
| * |
| * @cell: nvmem cell to be read. |
| * @len: pointer to length of cell which will be populated on successful read; |
| * can be NULL. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
| * buffer should be freed by the consumer with a kfree(). |
| */ |
| void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) |
| { |
| struct nvmem_device *nvmem = cell->nvmem; |
| u8 *buf; |
| int rc; |
| |
| if (!nvmem) |
| return ERR_PTR(-EINVAL); |
| |
| buf = kzalloc(cell->bytes, GFP_KERNEL); |
| if (!buf) |
| return ERR_PTR(-ENOMEM); |
| |
| rc = __nvmem_cell_read(nvmem, cell, buf, len); |
| if (rc) { |
| kfree(buf); |
| return ERR_PTR(rc); |
| } |
| |
| return buf; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read); |
| |
| static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell, |
| u8 *_buf, int len) |
| { |
| struct nvmem_device *nvmem = cell->nvmem; |
| int i, rc, nbits, bit_offset = cell->bit_offset; |
| u8 v, *p, *buf, *b, pbyte, pbits; |
| |
| nbits = cell->nbits; |
| buf = kzalloc(cell->bytes, GFP_KERNEL); |
| if (!buf) |
| return ERR_PTR(-ENOMEM); |
| |
| memcpy(buf, _buf, len); |
| p = b = buf; |
| |
| if (bit_offset) { |
| pbyte = *b; |
| *b <<= bit_offset; |
| |
| /* setup the first byte with lsb bits from nvmem */ |
| rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); |
| if (rc) |
| goto err; |
| *b++ |= GENMASK(bit_offset - 1, 0) & v; |
| |
| /* setup rest of the byte if any */ |
| for (i = 1; i < cell->bytes; i++) { |
| /* Get last byte bits and shift them towards lsb */ |
| pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); |
| pbyte = *b; |
| p = b; |
| *b <<= bit_offset; |
| *b++ |= pbits; |
| } |
| } |
| |
| /* if it's not end on byte boundary */ |
| if ((nbits + bit_offset) % BITS_PER_BYTE) { |
| /* setup the last byte with msb bits from nvmem */ |
| rc = nvmem_reg_read(nvmem, |
| cell->offset + cell->bytes - 1, &v, 1); |
| if (rc) |
| goto err; |
| *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; |
| |
| } |
| |
| return buf; |
| err: |
| kfree(buf); |
| return ERR_PTR(rc); |
| } |
| |
| /** |
| * nvmem_cell_write() - Write to a given nvmem cell |
| * |
| * @cell: nvmem cell to be written. |
| * @buf: Buffer to be written. |
| * @len: length of buffer to be written to nvmem cell. |
| * |
| * Return: length of bytes written or negative on failure. |
| */ |
| int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) |
| { |
| struct nvmem_device *nvmem = cell->nvmem; |
| int rc; |
| |
| if (!nvmem || nvmem->read_only || |
| (cell->bit_offset == 0 && len != cell->bytes)) |
| return -EINVAL; |
| |
| if (cell->bit_offset || cell->nbits) { |
| buf = nvmem_cell_prepare_write_buffer(cell, buf, len); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| } |
| |
| rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes); |
| |
| /* free the tmp buffer */ |
| if (cell->bit_offset || cell->nbits) |
| kfree(buf); |
| |
| if (rc) |
| return rc; |
| |
| return len; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_write); |
| |
| /** |
| * nvmem_cell_read_u32() - Read a cell value as an u32 |
| * |
| * @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_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; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); |
| |
| /** |
| * nvmem_device_cell_read() - Read a given nvmem device and cell |
| * |
| * @nvmem: nvmem device to read from. |
| * @info: nvmem cell info to be read. |
| * @buf: buffer pointer which will be populated on successful read. |
| * |
| * Return: length of successful bytes read on success and negative |
| * error code on error. |
| */ |
| ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, |
| struct nvmem_cell_info *info, void *buf) |
| { |
| struct nvmem_cell cell; |
| int rc; |
| ssize_t len; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); |
| if (rc) |
| return rc; |
| |
| rc = __nvmem_cell_read(nvmem, &cell, buf, &len); |
| if (rc) |
| return rc; |
| |
| return len; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_cell_read); |
| |
| /** |
| * nvmem_device_cell_write() - Write cell to a given nvmem device |
| * |
| * @nvmem: nvmem device to be written to. |
| * @info: nvmem cell info to be written. |
| * @buf: buffer to be written to cell. |
| * |
| * Return: length of bytes written or negative error code on failure. |
| * */ |
| int nvmem_device_cell_write(struct nvmem_device *nvmem, |
| struct nvmem_cell_info *info, void *buf) |
| { |
| struct nvmem_cell cell; |
| int rc; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell); |
| if (rc) |
| return rc; |
| |
| return nvmem_cell_write(&cell, buf, cell.bytes); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_cell_write); |
| |
| /** |
| * nvmem_device_read() - Read from a given nvmem device |
| * |
| * @nvmem: nvmem device to read from. |
| * @offset: offset in nvmem device. |
| * @bytes: number of bytes to read. |
| * @buf: buffer pointer which will be populated on successful read. |
| * |
| * Return: length of successful bytes read on success and negative |
| * error code on error. |
| */ |
| int nvmem_device_read(struct nvmem_device *nvmem, |
| unsigned int offset, |
| size_t bytes, void *buf) |
| { |
| int rc; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_reg_read(nvmem, offset, buf, bytes); |
| |
| if (rc) |
| return rc; |
| |
| return bytes; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_read); |
| |
| /** |
| * nvmem_device_write() - Write cell to a given nvmem device |
| * |
| * @nvmem: nvmem device to be written to. |
| * @offset: offset in nvmem device. |
| * @bytes: number of bytes to write. |
| * @buf: buffer to be written. |
| * |
| * Return: length of bytes written or negative error code on failure. |
| * */ |
| int nvmem_device_write(struct nvmem_device *nvmem, |
| unsigned int offset, |
| size_t bytes, void *buf) |
| { |
| int rc; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_reg_write(nvmem, offset, buf, bytes); |
| |
| if (rc) |
| return rc; |
| |
| |
| return bytes; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_write); |
| |
| static int __init nvmem_init(void) |
| { |
| return bus_register(&nvmem_bus_type); |
| } |
| |
| static void __exit nvmem_exit(void) |
| { |
| bus_unregister(&nvmem_bus_type); |
| } |
| |
| subsys_initcall(nvmem_init); |
| module_exit(nvmem_exit); |
| |
| MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); |
| MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); |
| MODULE_DESCRIPTION("nvmem Driver Core"); |
| MODULE_LICENSE("GPL v2"); |