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path: root/drivers/base/firmware_class.c
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Diffstat (limited to 'drivers/base/firmware_class.c')
-rw-r--r--drivers/base/firmware_class.c583
1 files changed, 583 insertions, 0 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
new file mode 100644
index 000000000000..26c9464af80a
--- /dev/null
+++ b/drivers/base/firmware_class.c
@@ -0,0 +1,583 @@
+/*
+ * firmware_class.c - Multi purpose firmware loading support
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ *
+ * Please see Documentation/firmware_class/ for more information.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/vmalloc.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <asm/semaphore.h>
+
+#include <linux/firmware.h>
+#include "base.h"
+
+MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
+MODULE_DESCRIPTION("Multi purpose firmware loading support");
+MODULE_LICENSE("GPL");
+
+enum {
+ FW_STATUS_LOADING,
+ FW_STATUS_DONE,
+ FW_STATUS_ABORT,
+ FW_STATUS_READY,
+};
+
+static int loading_timeout = 10; /* In seconds */
+
+/* fw_lock could be moved to 'struct firmware_priv' but since it is just
+ * guarding for corner cases a global lock should be OK */
+static DECLARE_MUTEX(fw_lock);
+
+struct firmware_priv {
+ char fw_id[FIRMWARE_NAME_MAX];
+ struct completion completion;
+ struct bin_attribute attr_data;
+ struct firmware *fw;
+ unsigned long status;
+ int alloc_size;
+ struct timer_list timeout;
+};
+
+static inline void
+fw_load_abort(struct firmware_priv *fw_priv)
+{
+ set_bit(FW_STATUS_ABORT, &fw_priv->status);
+ wmb();
+ complete(&fw_priv->completion);
+}
+
+static ssize_t
+firmware_timeout_show(struct class *class, char *buf)
+{
+ return sprintf(buf, "%d\n", loading_timeout);
+}
+
+/**
+ * firmware_timeout_store:
+ * Description:
+ * Sets the number of seconds to wait for the firmware. Once
+ * this expires an error will be return to the driver and no
+ * firmware will be provided.
+ *
+ * Note: zero means 'wait for ever'
+ *
+ **/
+static ssize_t
+firmware_timeout_store(struct class *class, const char *buf, size_t count)
+{
+ loading_timeout = simple_strtol(buf, NULL, 10);
+ return count;
+}
+
+static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
+
+static void fw_class_dev_release(struct class_device *class_dev);
+int firmware_class_hotplug(struct class_device *dev, char **envp,
+ int num_envp, char *buffer, int buffer_size);
+
+static struct class firmware_class = {
+ .name = "firmware",
+ .hotplug = firmware_class_hotplug,
+ .release = fw_class_dev_release,
+};
+
+int
+firmware_class_hotplug(struct class_device *class_dev, char **envp,
+ int num_envp, char *buffer, int buffer_size)
+{
+ struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+ int i = 0, len = 0;
+
+ if (!test_bit(FW_STATUS_READY, &fw_priv->status))
+ return -ENODEV;
+
+ if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len,
+ "FIRMWARE=%s", fw_priv->fw_id))
+ return -ENOMEM;
+
+ envp[i] = NULL;
+
+ return 0;
+}
+
+static ssize_t
+firmware_loading_show(struct class_device *class_dev, char *buf)
+{
+ struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+ int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
+ return sprintf(buf, "%d\n", loading);
+}
+
+/**
+ * firmware_loading_store: - loading control file
+ * Description:
+ * The relevant values are:
+ *
+ * 1: Start a load, discarding any previous partial load.
+ * 0: Conclude the load and handle the data to the driver code.
+ * -1: Conclude the load with an error and discard any written data.
+ **/
+static ssize_t
+firmware_loading_store(struct class_device *class_dev,
+ const char *buf, size_t count)
+{
+ struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+ int loading = simple_strtol(buf, NULL, 10);
+
+ switch (loading) {
+ case 1:
+ down(&fw_lock);
+ vfree(fw_priv->fw->data);
+ fw_priv->fw->data = NULL;
+ fw_priv->fw->size = 0;
+ fw_priv->alloc_size = 0;
+ set_bit(FW_STATUS_LOADING, &fw_priv->status);
+ up(&fw_lock);
+ break;
+ case 0:
+ if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
+ complete(&fw_priv->completion);
+ clear_bit(FW_STATUS_LOADING, &fw_priv->status);
+ break;
+ }
+ /* fallthrough */
+ default:
+ printk(KERN_ERR "%s: unexpected value (%d)\n", __FUNCTION__,
+ loading);
+ /* fallthrough */
+ case -1:
+ fw_load_abort(fw_priv);
+ break;
+ }
+
+ return count;
+}
+
+static CLASS_DEVICE_ATTR(loading, 0644,
+ firmware_loading_show, firmware_loading_store);
+
+static ssize_t
+firmware_data_read(struct kobject *kobj,
+ char *buffer, loff_t offset, size_t count)
+{
+ struct class_device *class_dev = to_class_dev(kobj);
+ struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+ struct firmware *fw;
+ ssize_t ret_count = count;
+
+ down(&fw_lock);
+ fw = fw_priv->fw;
+ if (test_bit(FW_STATUS_DONE, &fw_priv->status)) {
+ ret_count = -ENODEV;
+ goto out;
+ }
+ if (offset > fw->size) {
+ ret_count = 0;
+ goto out;
+ }
+ if (offset + ret_count > fw->size)
+ ret_count = fw->size - offset;
+
+ memcpy(buffer, fw->data + offset, ret_count);
+out:
+ up(&fw_lock);
+ return ret_count;
+}
+static int
+fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
+{
+ u8 *new_data;
+
+ if (min_size <= fw_priv->alloc_size)
+ return 0;
+
+ new_data = vmalloc(fw_priv->alloc_size + PAGE_SIZE);
+ if (!new_data) {
+ printk(KERN_ERR "%s: unable to alloc buffer\n", __FUNCTION__);
+ /* Make sure that we don't keep incomplete data */
+ fw_load_abort(fw_priv);
+ return -ENOMEM;
+ }
+ fw_priv->alloc_size += PAGE_SIZE;
+ if (fw_priv->fw->data) {
+ memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
+ vfree(fw_priv->fw->data);
+ }
+ fw_priv->fw->data = new_data;
+ BUG_ON(min_size > fw_priv->alloc_size);
+ return 0;
+}
+
+/**
+ * firmware_data_write:
+ *
+ * Description:
+ *
+ * Data written to the 'data' attribute will be later handled to
+ * the driver as a firmware image.
+ **/
+static ssize_t
+firmware_data_write(struct kobject *kobj,
+ char *buffer, loff_t offset, size_t count)
+{
+ struct class_device *class_dev = to_class_dev(kobj);
+ struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+ struct firmware *fw;
+ ssize_t retval;
+
+ if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;
+ down(&fw_lock);
+ fw = fw_priv->fw;
+ if (test_bit(FW_STATUS_DONE, &fw_priv->status)) {
+ retval = -ENODEV;
+ goto out;
+ }
+ retval = fw_realloc_buffer(fw_priv, offset + count);
+ if (retval)
+ goto out;
+
+ memcpy(fw->data + offset, buffer, count);
+
+ fw->size = max_t(size_t, offset + count, fw->size);
+ retval = count;
+out:
+ up(&fw_lock);
+ return retval;
+}
+static struct bin_attribute firmware_attr_data_tmpl = {
+ .attr = {.name = "data", .mode = 0644, .owner = THIS_MODULE},
+ .size = 0,
+ .read = firmware_data_read,
+ .write = firmware_data_write,
+};
+
+static void
+fw_class_dev_release(struct class_device *class_dev)
+{
+ struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+ kfree(fw_priv);
+ kfree(class_dev);
+
+ module_put(THIS_MODULE);
+}
+
+static void
+firmware_class_timeout(u_long data)
+{
+ struct firmware_priv *fw_priv = (struct firmware_priv *) data;
+ fw_load_abort(fw_priv);
+}
+
+static inline void
+fw_setup_class_device_id(struct class_device *class_dev, struct device *dev)
+{
+ /* XXX warning we should watch out for name collisions */
+ strlcpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE);
+}
+
+static int
+fw_register_class_device(struct class_device **class_dev_p,
+ const char *fw_name, struct device *device)
+{
+ int retval;
+ struct firmware_priv *fw_priv = kmalloc(sizeof (struct firmware_priv),
+ GFP_KERNEL);
+ struct class_device *class_dev = kmalloc(sizeof (struct class_device),
+ GFP_KERNEL);
+
+ *class_dev_p = NULL;
+
+ if (!fw_priv || !class_dev) {
+ printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__);
+ retval = -ENOMEM;
+ goto error_kfree;
+ }
+ memset(fw_priv, 0, sizeof (*fw_priv));
+ memset(class_dev, 0, sizeof (*class_dev));
+
+ init_completion(&fw_priv->completion);
+ fw_priv->attr_data = firmware_attr_data_tmpl;
+ strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
+
+ fw_priv->timeout.function = firmware_class_timeout;
+ fw_priv->timeout.data = (u_long) fw_priv;
+ init_timer(&fw_priv->timeout);
+
+ fw_setup_class_device_id(class_dev, device);
+ class_dev->dev = device;
+ class_dev->class = &firmware_class;
+ class_set_devdata(class_dev, fw_priv);
+ retval = class_device_register(class_dev);
+ if (retval) {
+ printk(KERN_ERR "%s: class_device_register failed\n",
+ __FUNCTION__);
+ goto error_kfree;
+ }
+ *class_dev_p = class_dev;
+ return 0;
+
+error_kfree:
+ kfree(fw_priv);
+ kfree(class_dev);
+ return retval;
+}
+
+static int
+fw_setup_class_device(struct firmware *fw, struct class_device **class_dev_p,
+ const char *fw_name, struct device *device)
+{
+ struct class_device *class_dev;
+ struct firmware_priv *fw_priv;
+ int retval;
+
+ *class_dev_p = NULL;
+ retval = fw_register_class_device(&class_dev, fw_name, device);
+ if (retval)
+ goto out;
+
+ /* Need to pin this module until class device is destroyed */
+ __module_get(THIS_MODULE);
+
+ fw_priv = class_get_devdata(class_dev);
+
+ fw_priv->fw = fw;
+ retval = sysfs_create_bin_file(&class_dev->kobj, &fw_priv->attr_data);
+ if (retval) {
+ printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
+ __FUNCTION__);
+ goto error_unreg;
+ }
+
+ retval = class_device_create_file(class_dev,
+ &class_device_attr_loading);
+ if (retval) {
+ printk(KERN_ERR "%s: class_device_create_file failed\n",
+ __FUNCTION__);
+ goto error_unreg;
+ }
+
+ set_bit(FW_STATUS_READY, &fw_priv->status);
+ *class_dev_p = class_dev;
+ goto out;
+
+error_unreg:
+ class_device_unregister(class_dev);
+out:
+ return retval;
+}
+
+/**
+ * request_firmware: - request firmware to hotplug and wait for it
+ * Description:
+ * @firmware will be used to return a firmware image by the name
+ * of @name for device @device.
+ *
+ * Should be called from user context where sleeping is allowed.
+ *
+ * @name will be use as $FIRMWARE in the hotplug environment and
+ * should be distinctive enough not to be confused with any other
+ * firmware image for this or any other device.
+ **/
+int
+request_firmware(const struct firmware **firmware_p, const char *name,
+ struct device *device)
+{
+ struct class_device *class_dev;
+ struct firmware_priv *fw_priv;
+ struct firmware *firmware;
+ int retval;
+
+ if (!firmware_p)
+ return -EINVAL;
+
+ *firmware_p = firmware = kmalloc(sizeof (struct firmware), GFP_KERNEL);
+ if (!firmware) {
+ printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
+ __FUNCTION__);
+ retval = -ENOMEM;
+ goto out;
+ }
+ memset(firmware, 0, sizeof (*firmware));
+
+ retval = fw_setup_class_device(firmware, &class_dev, name, device);
+ if (retval)
+ goto error_kfree_fw;
+
+ fw_priv = class_get_devdata(class_dev);
+
+ if (loading_timeout) {
+ fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
+ add_timer(&fw_priv->timeout);
+ }
+
+ kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
+ wait_for_completion(&fw_priv->completion);
+ set_bit(FW_STATUS_DONE, &fw_priv->status);
+
+ del_timer_sync(&fw_priv->timeout);
+
+ down(&fw_lock);
+ if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
+ retval = -ENOENT;
+ release_firmware(fw_priv->fw);
+ *firmware_p = NULL;
+ }
+ fw_priv->fw = NULL;
+ up(&fw_lock);
+ class_device_unregister(class_dev);
+ goto out;
+
+error_kfree_fw:
+ kfree(firmware);
+ *firmware_p = NULL;
+out:
+ return retval;
+}
+
+/**
+ * release_firmware: - release the resource associated with a firmware image
+ **/
+void
+release_firmware(const struct firmware *fw)
+{
+ if (fw) {
+ vfree(fw->data);
+ kfree(fw);
+ }
+}
+
+/**
+ * register_firmware: - provide a firmware image for later usage
+ *
+ * Description:
+ * Make sure that @data will be available by requesting firmware @name.
+ *
+ * Note: This will not be possible until some kind of persistence
+ * is available.
+ **/
+void
+register_firmware(const char *name, const u8 *data, size_t size)
+{
+ /* This is meaningless without firmware caching, so until we
+ * decide if firmware caching is reasonable just leave it as a
+ * noop */
+}
+
+/* Async support */
+struct firmware_work {
+ struct work_struct work;
+ struct module *module;
+ const char *name;
+ struct device *device;
+ void *context;
+ void (*cont)(const struct firmware *fw, void *context);
+};
+
+static int
+request_firmware_work_func(void *arg)
+{
+ struct firmware_work *fw_work = arg;
+ const struct firmware *fw;
+ if (!arg) {
+ WARN_ON(1);
+ return 0;
+ }
+ daemonize("%s/%s", "firmware", fw_work->name);
+ request_firmware(&fw, fw_work->name, fw_work->device);
+ fw_work->cont(fw, fw_work->context);
+ release_firmware(fw);
+ module_put(fw_work->module);
+ kfree(fw_work);
+ return 0;
+}
+
+/**
+ * request_firmware_nowait:
+ *
+ * Description:
+ * Asynchronous variant of request_firmware() for contexts where
+ * it is not possible to sleep.
+ *
+ * @cont will be called asynchronously when the firmware request is over.
+ *
+ * @context will be passed over to @cont.
+ *
+ * @fw may be %NULL if firmware request fails.
+ *
+ **/
+int
+request_firmware_nowait(
+ struct module *module,
+ const char *name, struct device *device, void *context,
+ void (*cont)(const struct firmware *fw, void *context))
+{
+ struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
+ GFP_ATOMIC);
+ int ret;
+
+ if (!fw_work)
+ return -ENOMEM;
+ if (!try_module_get(module)) {
+ kfree(fw_work);
+ return -EFAULT;
+ }
+
+ *fw_work = (struct firmware_work) {
+ .module = module,
+ .name = name,
+ .device = device,
+ .context = context,
+ .cont = cont,
+ };
+
+ ret = kernel_thread(request_firmware_work_func, fw_work,
+ CLONE_FS | CLONE_FILES);
+
+ if (ret < 0) {
+ fw_work->cont(NULL, fw_work->context);
+ return ret;
+ }
+ return 0;
+}
+
+static int __init
+firmware_class_init(void)
+{
+ int error;
+ error = class_register(&firmware_class);
+ if (error) {
+ printk(KERN_ERR "%s: class_register failed\n", __FUNCTION__);
+ return error;
+ }
+ error = class_create_file(&firmware_class, &class_attr_timeout);
+ if (error) {
+ printk(KERN_ERR "%s: class_create_file failed\n",
+ __FUNCTION__);
+ class_unregister(&firmware_class);
+ }
+ return error;
+
+}
+static void __exit
+firmware_class_exit(void)
+{
+ class_unregister(&firmware_class);
+}
+
+module_init(firmware_class_init);
+module_exit(firmware_class_exit);
+
+EXPORT_SYMBOL(release_firmware);
+EXPORT_SYMBOL(request_firmware);
+EXPORT_SYMBOL(request_firmware_nowait);
+EXPORT_SYMBOL(register_firmware);