linux/drivers/base/firmware_class.c
Kay Sievers 312c004d36 [PATCH] driver core: replace "hotplug" by "uevent"
Leave the overloaded "hotplug" word to susbsystems which are handling
real devices. The driver core does not "plug" anything, it just exports
the state to userspace and generates events.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-04 16:18:08 -08:00

630 lines
15 KiB
C

/*
* 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,
FW_STATUS_READY_NOHOTPLUG,
};
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 - set number of seconds to wait for firmware
* @class: device class pointer
* @buf: buffer to scan for timeout value
* @count: number of bytes in @buf
*
* Sets the number of seconds to wait for the firmware. Once
* this expires an error will be returned to the driver and no
* firmware will be provided.
*
* Note: zero means 'wait forever'.
**/
static ssize_t
firmware_timeout_store(struct class *class, const char *buf, size_t count)
{
loading_timeout = simple_strtol(buf, NULL, 10);
if (loading_timeout < 0)
loading_timeout = 0;
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_uevent(struct class_device *dev, char **envp,
int num_envp, char *buffer, int buffer_size);
static struct class firmware_class = {
.name = "firmware",
.uevent = firmware_class_uevent,
.release = fw_class_dev_release,
};
int
firmware_class_uevent(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_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
"FIRMWARE=%s", fw_priv->fw_id))
return -ENOMEM;
if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
"TIMEOUT=%i", loading_timeout))
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 - set value in the 'loading' control file
* @class_dev: class_device pointer
* @buf: buffer to scan for loading control value
* @count: number of bytes in @buf
*
* The relevant values are:
*
* 1: Start a load, discarding any previous partial load.
* 0: Conclude the load and hand 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);
if (!fw_priv->fw) {
up(&fw_lock);
break;
}
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 (!fw || 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 - write method for firmware
* @kobj: kobject for the class_device
* @buffer: buffer being written
* @offset: buffer offset for write in total data store area
* @count: buffer size
*
* Data written to the 'data' attribute will be later handed 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 (!fw || 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 = kzalloc(sizeof(*fw_priv),
GFP_KERNEL);
struct class_device *class_dev = kzalloc(sizeof(*class_dev),
GFP_KERNEL);
*class_dev_p = NULL;
if (!fw_priv || !class_dev) {
printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__);
retval = -ENOMEM;
goto error_kfree;
}
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, int uevent)
{
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;
}
if (uevent)
set_bit(FW_STATUS_READY, &fw_priv->status);
else
set_bit(FW_STATUS_READY_NOHOTPLUG, &fw_priv->status);
*class_dev_p = class_dev;
goto out;
error_unreg:
class_device_unregister(class_dev);
out:
return retval;
}
static int
_request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device, int uevent)
{
struct class_device *class_dev;
struct firmware_priv *fw_priv;
struct firmware *firmware;
int retval;
if (!firmware_p)
return -EINVAL;
*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
if (!firmware) {
printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
__FUNCTION__);
retval = -ENOMEM;
goto out;
}
retval = fw_setup_class_device(firmware, &class_dev, name, device,
uevent);
if (retval)
goto error_kfree_fw;
fw_priv = class_get_devdata(class_dev);
if (uevent) {
if (loading_timeout > 0) {
fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
add_timer(&fw_priv->timeout);
}
kobject_uevent(&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);
} else
wait_for_completion(&fw_priv->completion);
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;
}
/**
* request_firmware: - send firmware request and wait for it
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* @firmware_p 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 used as $FIRMWARE in the uevent 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)
{
int uevent = 1;
return _request_firmware(firmware_p, name, device, uevent);
}
/**
* release_firmware: - release the resource associated with a firmware image
* @fw: firmware resource to release
**/
void
release_firmware(const struct firmware *fw)
{
if (fw) {
vfree(fw->data);
kfree(fw);
}
}
/**
* register_firmware: - provide a firmware image for later usage
* @name: name of firmware image file
* @data: buffer pointer for the firmware image
* @size: size of the data buffer area
*
* 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);
int uevent;
};
static int
request_firmware_work_func(void *arg)
{
struct firmware_work *fw_work = arg;
const struct firmware *fw;
int ret;
if (!arg) {
WARN_ON(1);
return 0;
}
daemonize("%s/%s", "firmware", fw_work->name);
ret = _request_firmware(&fw, fw_work->name, fw_work->device,
fw_work->uevent);
if (ret < 0)
fw_work->cont(NULL, fw_work->context);
else {
fw_work->cont(fw, fw_work->context);
release_firmware(fw);
}
module_put(fw_work->module);
kfree(fw_work);
return ret;
}
/**
* request_firmware_nowait: asynchronous version of request_firmware
* @module: module requesting the firmware
* @uevent: sends uevent to copy the firmware image if this flag
* is non-zero else the firmware copy must be done manually.
* @name: name of firmware file
* @device: device for which firmware is being loaded
* @context: will be passed over to @cont, and
* @fw may be %NULL if firmware request fails.
* @cont: function will be called asynchronously when the firmware
* request is over.
*
* Asynchronous variant of request_firmware() for contexts where
* it is not possible to sleep.
**/
int
request_firmware_nowait(
struct module *module, int uevent,
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,
.uevent = uevent,
};
ret = kernel_thread(request_firmware_work_func, fw_work,
CLONE_FS | CLONE_FILES);
if (ret < 0) {
fw_work->cont(NULL, fw_work->context);
module_put(fw_work->module);
kfree(fw_work);
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);