mirror of https://github.com/hak5/openwrt.git
182 lines
4.7 KiB
Diff
182 lines
4.7 KiB
Diff
From b6c217ab9be6895384cf0b284ace84ad79e5c53b Mon Sep 17 00:00:00 2001
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From: Andrew Lunn <andrew@lunn.ch>
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Date: Fri, 26 Feb 2016 20:59:19 +0100
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Subject: nvmem: Add backwards compatibility support for older EEPROM drivers.
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Older drivers made an 'eeprom' file available in the /sys device
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directory. Have the NVMEM core provide this to retain backwards
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compatibility.
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Signed-off-by: Andrew Lunn <andrew@lunn.ch>
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Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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drivers/nvmem/core.c | 84 ++++++++++++++++++++++++++++++++++++++----
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include/linux/nvmem-provider.h | 4 +-
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2 files changed, 79 insertions(+), 9 deletions(-)
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--- a/drivers/nvmem/core.c
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+++ b/drivers/nvmem/core.c
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@@ -38,8 +38,13 @@ struct nvmem_device {
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int users;
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size_t size;
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bool read_only;
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+ int flags;
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+ struct bin_attribute eeprom;
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+ struct device *base_dev;
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};
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+#define FLAG_COMPAT BIT(0)
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+
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struct nvmem_cell {
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const char *name;
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int offset;
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@@ -56,16 +61,26 @@ static DEFINE_IDA(nvmem_ida);
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static LIST_HEAD(nvmem_cells);
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static DEFINE_MUTEX(nvmem_cells_mutex);
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+#ifdef CONFIG_DEBUG_LOCK_ALLOC
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+static struct lock_class_key eeprom_lock_key;
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+#endif
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+
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#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
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static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *attr,
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char *buf, loff_t pos, size_t count)
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{
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- struct device *dev = container_of(kobj, struct device, kobj);
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- struct nvmem_device *nvmem = to_nvmem_device(dev);
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+ struct device *dev;
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+ struct nvmem_device *nvmem;
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int rc;
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+ if (attr->private)
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+ dev = attr->private;
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+ else
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+ dev = container_of(kobj, struct device, kobj);
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+ nvmem = to_nvmem_device(dev);
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+
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/* Stop the user from reading */
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if (pos >= nvmem->size)
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return 0;
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@@ -90,10 +105,16 @@ static ssize_t bin_attr_nvmem_write(stru
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struct bin_attribute *attr,
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char *buf, loff_t pos, size_t count)
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{
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- struct device *dev = container_of(kobj, struct device, kobj);
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- struct nvmem_device *nvmem = to_nvmem_device(dev);
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+ struct device *dev;
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+ struct nvmem_device *nvmem;
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int rc;
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+ if (attr->private)
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+ dev = attr->private;
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+ else
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+ dev = container_of(kobj, struct device, kobj);
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+ nvmem = to_nvmem_device(dev);
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+
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/* Stop the user from writing */
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if (pos >= nvmem->size)
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return 0;
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@@ -349,6 +370,43 @@ err:
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return rval;
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}
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+/*
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+ * nvmem_setup_compat() - Create an additional binary entry in
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+ * drivers sys directory, to be backwards compatible with the older
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+ * drivers/misc/eeprom drivers.
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+ */
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+static int nvmem_setup_compat(struct nvmem_device *nvmem,
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+ const struct nvmem_config *config)
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+{
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+ int rval;
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+
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+ if (!config->base_dev)
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+ return -EINVAL;
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+
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+ if (nvmem->read_only)
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+ nvmem->eeprom = bin_attr_ro_root_nvmem;
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+ else
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+ nvmem->eeprom = bin_attr_rw_root_nvmem;
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+ nvmem->eeprom.attr.name = "eeprom";
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+ nvmem->eeprom.size = nvmem->size;
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+#ifdef CONFIG_DEBUG_LOCK_ALLOC
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+ nvmem->eeprom.attr.key = &eeprom_lock_key;
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+#endif
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+ nvmem->eeprom.private = &nvmem->dev;
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+ nvmem->base_dev = config->base_dev;
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+
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+ rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);
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+ if (rval) {
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+ dev_err(&nvmem->dev,
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+ "Failed to create eeprom binary file %d\n", rval);
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+ return rval;
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+ }
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+
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+ nvmem->flags |= FLAG_COMPAT;
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+
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+ return 0;
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+}
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+
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/**
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* nvmem_register() - Register a nvmem device for given nvmem_config.
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* Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
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@@ -416,16 +474,23 @@ struct nvmem_device *nvmem_register(cons
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dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
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rval = device_add(&nvmem->dev);
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- if (rval) {
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- ida_simple_remove(&nvmem_ida, nvmem->id);
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- kfree(nvmem);
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- return ERR_PTR(rval);
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+ if (rval)
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+ goto out;
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+
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+ if (config->compat) {
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+ rval = nvmem_setup_compat(nvmem, config);
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+ if (rval)
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+ goto out;
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}
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if (config->cells)
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nvmem_add_cells(nvmem, config);
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return nvmem;
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+out:
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+ ida_simple_remove(&nvmem_ida, nvmem->id);
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+ kfree(nvmem);
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+ return ERR_PTR(rval);
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}
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EXPORT_SYMBOL_GPL(nvmem_register);
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@@ -445,6 +510,9 @@ int nvmem_unregister(struct nvmem_device
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}
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mutex_unlock(&nvmem_mutex);
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+ if (nvmem->flags & FLAG_COMPAT)
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+ device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
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+
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nvmem_device_remove_all_cells(nvmem);
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device_del(&nvmem->dev);
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--- a/include/linux/nvmem-provider.h
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+++ b/include/linux/nvmem-provider.h
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@@ -24,6 +24,9 @@ struct nvmem_config {
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int ncells;
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bool read_only;
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bool root_only;
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+ /* To be only used by old driver/misc/eeprom drivers */
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+ bool compat;
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+ struct device *base_dev;
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};
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#if IS_ENABLED(CONFIG_NVMEM)
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@@ -44,5 +47,4 @@ static inline int nvmem_unregister(struc
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}
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#endif /* CONFIG_NVMEM */
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-
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#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */
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