Merge bk://kernel.bkbits.net/gregkh/linux/firmware-2.5

into osdl.org:/home/mochel/src/kernel/devel/linux-2.5-core

Documentation/firmware_class/README

+
+ request_firmware() hotplug interface:
+ ------------------------------------
+	Copyright (C) 2003 Manuel Estrada Sainz <ranty@debian.org>
+
+ Why:
+ ---
+
+ Today, the most extended way to use firmware in the Linux kernel is linking
+ it statically in a header file. Which has political and technical issues:
+
+  1) Some firmware is not legal to redistribute.
+  2) The firmware occupies memory permanently, even though it often is just
+     used once.
+  3) Some people, like the Debian crowd, don't consider some firmware free
+     enough and remove entire drivers (e.g.: keyspan).
+
+ about in-kernel persistence:
+ ---------------------------
+ Under some circumstances, as explained below, it would be interesting to keep
+ firmware images in non-swappable kernel memory or even in the kernel image
+ (probably within initramfs).
+
+ Note that this functionality has not been implemented.
+
+ - Why OPTIONAL in-kernel persistence may be a good idea sometimes:
+ 
+	- If the device that needs the firmware is needed to access the
+	  filesystem. When upon some error the device has to be reset and the
+	  firmware reloaded, it won't be possible to get it from userspace.
+	  e.g.:
+		- A diskless client with a network card that needs firmware.
+		- The filesystem is stored in a disk behind an scsi device
+		  that needs firmware.
+	- Replacing buggy DSDT/SSDT ACPI tables on boot.
+	  Note: this would require the persistent objects to be included
+	  within the kernel image, probably within initramfs.
+	  
+   And the same device can be needed to access the filesystem or not depending
+   on the setup, so I think that the choice on what firmware to make
+   persistent should be left to userspace.
+
+ - Why register_firmware()+__init can be useful:
+ 	- For boot devices needing firmware.
+	- To make the transition easier:
+		The firmware can be declared __init and register_firmware()
+		called on module_init. Then the firmware is warranted to be
+		there even if "firmware hotplug userspace" is not there yet or
+		it doesn't yet provide the needed firmware.
+		Once the firmware is widely available in userspace, it can be
+		removed from the kernel. Or made optional (CONFIG_.*_FIRMWARE).
+
+	In either case, if firmware hotplug support is there, it can move the
+	firmware out of kernel memory into the real filesystem for later
+	usage.
+
+	Note: If persistence is implemented on top of initramfs,
+	register_firmware() may not be appropriate.

Documentation/firmware_class/firmware_sample_driver.c

+/*
+ * firmware_sample_driver.c -
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ *
+ * Sample code on how to use request_firmware() from drivers.
+ *
+ * Note that register_firmware() is currently useless.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+
+#include "linux/firmware.h"
+
+#define WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+char __init inkernel_firmware[] = "let's say that this is firmware\n";
+#endif
+
+static struct device ghost_device = {
+	.name      = "Ghost Device",
+	.bus_id    = "ghost0",
+};
+
+
+static void sample_firmware_load(char *firmware, int size)
+{
+	u8 buf[size+1];
+	memcpy(buf, firmware, size);
+	buf[size] = '\0';
+	printk("firmware_sample_driver: firmware: %s\n", buf);
+}
+
+static void sample_probe_default(void)
+{
+	/* uses the default method to get the firmware */
+        const struct firmware *fw_entry;
+	printk("firmware_sample_driver: a ghost device got inserted :)\n");
+
+        if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0)
+	{
+		printk(KERN_ERR
+		       "firmware_sample_driver: Firmware not available\n");
+		return;
+	}
+	
+	sample_firmware_load(fw_entry->data, fw_entry->size);
+
+	release_firmware(fw_entry);
+
+	/* finish setting up the device */
+}
+static void sample_probe_specific(void)
+{
+	/* Uses some specific hotplug support to get the firmware from
+	 * userspace  directly into the hardware, or via some sysfs file */
+
+	/* NOTE: This currently doesn't work */
+
+	printk("firmware_sample_driver: a ghost device got inserted :)\n");
+
+        if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0)
+	{
+		printk(KERN_ERR
+		       "firmware_sample_driver: Firmware load failed\n");
+		return;
+	}
+	
+	/* request_firmware blocks until userspace finished, so at
+	 * this point the firmware should be already in the device */
+
+	/* finish setting up the device */
+}
+static void sample_probe_async_cont(const struct firmware *fw, void *context)
+{
+	if(!fw){
+		printk(KERN_ERR
+		       "firmware_sample_driver: firmware load failed\n");
+		return;
+	}
+
+	printk("firmware_sample_driver: device pointer \"%s\"\n",
+	       (char *)context);
+	sample_firmware_load(fw->data, fw->size);
+}
+static void sample_probe_async(void)
+{
+	/* Let's say that I can't sleep */
+	int error;
+	error = request_firmware_nowait (THIS_MODULE,
+					 "sample_driver_fw", &ghost_device,
+					 "my device pointer",
+					 sample_probe_async_cont);
+	if(error){
+		printk(KERN_ERR 
+		       "firmware_sample_driver:"
+		       " request_firmware_nowait failed\n");
+	}
+}
+
+static int sample_init(void)
+{
+#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+	register_firmware("sample_driver_fw", inkernel_firmware,
+			  sizeof(inkernel_firmware));
+#endif
+	device_initialize(&ghost_device);
+	/* since there is no real hardware insertion I just call the
+	 * sample probe functions here */
+	sample_probe_specific();
+	sample_probe_default();
+	sample_probe_async();
+	return 0;
+}
+static void __exit sample_exit(void)
+{
+}
+
+module_init (sample_init);
+module_exit (sample_exit);
+
+MODULE_LICENSE("GPL");

Documentation/firmware_class/firmware_sample_firmware_class.c

+/*
+ * firmware_sample_firmware_class.c -
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ *
+ * NOTE: This is just a probe of concept, if you think that your driver would
+ * be well served by this mechanism please contact me first.
+ *
+ * DON'T USE THIS CODE AS IS
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <asm/hardirq.h>
+
+#include "linux/firmware.h"
+
+MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
+MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
+MODULE_LICENSE("GPL");
+
+static inline struct class_device *to_class_dev(struct kobject *obj)
+{
+	return container_of(obj,struct class_device,kobj);
+}
+static inline
+struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
+{
+	return container_of(_attr,struct class_device_attribute,attr);
+}
+
+int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+
+struct firmware_priv {
+	char fw_id[FIRMWARE_NAME_MAX];
+	s32 loading:2;
+	u32 abort:1;
+};
+
+extern struct class firmware_class;
+
+static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	return sprintf(buf, "%d\n", fw_priv->loading);
+}
+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 prev_loading = fw_priv->loading;
+
+	fw_priv->loading = simple_strtol(buf, NULL, 10);
+	
+	switch(fw_priv->loading){
+	case -1:
+		/* abort load an panic */
+		break;
+	case 1:
+		/* setup load */
+		break;
+	case 0:
+		if(prev_loading==1){
+			/* finish load and get the device back to working
+			 * state */
+		}
+		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);
+
+	/* read from the devices firmware memory */
+
+	return count;
+}
+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);
+
+	/* write to the devices firmware memory */
+
+	return count;
+}
+static struct bin_attribute firmware_attr_data = {
+	.attr = {.name = "data", .mode = 0644},
+	.size = 0,
+	.read = firmware_data_read,
+	.write = firmware_data_write,
+};
+static int fw_setup_class_device(struct class_device *class_dev,
+				 const char *fw_name,
+				 struct device *device)
+{
+	int retval = 0;
+	struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
+						GFP_KERNEL);
+
+	if(!fw_priv){
+		retval = -ENOMEM;
+		goto out;
+	}
+	memset(fw_priv, 0, sizeof(*fw_priv));
+	memset(class_dev, 0, sizeof(*class_dev));
+
+	strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
+	fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
+
+	strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
+	class_dev->class_id[BUS_ID_SIZE-1] = '\0';
+	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_free_fw_priv;
+	}
+
+	retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
+	if (retval){
+		printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
+		       __FUNCTION__);
+		goto error_unreg_class_dev;
+	}
+
+	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_remove_data;
+	}
+
+	goto out;
+	
+error_remove_data:
+	sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
+error_unreg_class_dev:
+	class_device_unregister(class_dev);
+error_free_fw_priv:
+	kfree(fw_priv);
+out:
+	return retval;
+}
+static void fw_remove_class_device(struct class_device *class_dev)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+	class_device_remove_file(class_dev, &class_device_attr_loading);
+	sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
+	class_device_unregister(class_dev);
+}
+
+static struct class_device *class_dev;
+
+static struct device my_device = {
+	.name      = "Sample Device",
+	.bus_id    = "my_dev0",
+};
+
+static int __init firmware_sample_init(void)
+{
+	int error;
+
+	device_initialize(&my_device);
+	class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
+	if(!class_dev)
+		return -ENOMEM;
+
+	error = fw_setup_class_device(class_dev, "my_firmware_image",
+				      &my_device);
+	if(error){
+		kfree(class_dev);
+		return error;
+	}
+        return 0;
+
+}
+static void __exit firmware_sample_exit(void)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	fw_remove_class_device(class_dev);
+	kfree(fw_priv);
+	kfree(class_dev);
+}
+module_init(firmware_sample_init);
+module_exit(firmware_sample_exit);
+

Documentation/firmware_class/hotplug-script

+#!/bin/sh
+
+# Simple hotplug script sample:
+# 
+# Both $DEVPATH and $FIRMWARE are already provided in the environment.
+
+HOTPLUG_FW_DIR=/usr/lib/hotplug/firmware/
+
+echo 1 > /sysfs/$DEVPATH/loading
+cat $HOTPLUG_FW_DIR/$FIRMWARE > /sysfs/$DEVPATH/data
+echo 0 > /sysfs/$DEVPATH/loading
+
+# To cancel the load in case of error:
+#
+#	echo -1 > /sysfs/$DEVPATH/loading
+#

arch/alpha/Kconfig

@@ -653,6 +653,8 @@ source "drivers/parport/Kconfig"
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/pnp/Kconfig"

arch/arm/Kconfig

@@ -703,6 +703,8 @@ endchoice
 
 source "fs/Kconfig.binfmt"
 
+source "drivers/base/Kconfig"
+
 config PM
 	bool "Power Management support"
 	---help---

arch/arm26/Kconfig

@@ -297,6 +297,8 @@ config CMDLINE
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/parport/Kconfig"
 
 source "drivers/pnp/Kconfig"

arch/cris/Kconfig

@@ -515,6 +515,8 @@ config ETRAX_POWERBUTTON_BIT
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 # bring in Etrax built-in drivers
 source "arch/cris/drivers/Kconfig"
 

arch/h8300/Kconfig

@@ -145,6 +145,8 @@ source "fs/Kconfig.binfmt"
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/block/Kconfig"
 
 source "drivers/ide/Kconfig"

arch/i386/Kconfig

@@ -1194,6 +1194,8 @@ source "fs/Kconfig.binfmt"
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/ia64/Kconfig

@@ -534,6 +534,8 @@ endif
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 if !IA64_HP_SIM
 
 source "drivers/mtd/Kconfig"

arch/m68k/Kconfig

@@ -573,6 +573,8 @@ endif
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/block/Kconfig"

arch/m68knommu/Kconfig

@@ -515,6 +515,8 @@ config PM
 endmenu
 
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/mips/Kconfig

@@ -744,6 +744,8 @@ if ISA
 source "drivers/pnp/Kconfig"
 endif
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/mips64/Kconfig

@@ -361,6 +361,8 @@ endmenu
 
 source "drivers/pci/Kconfig"
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/parisc/Kconfig

@@ -170,6 +170,8 @@ source "fs/Kconfig.binfmt"
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 # source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/ppc/Kconfig

@@ -1163,6 +1163,8 @@ config PIN_TLB
 	depends on ADVANCED_OPTIONS && 8xx
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/pnp/Kconfig"

arch/ppc64/Kconfig

@@ -241,6 +241,8 @@ config CMDLINE
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/s390/Kconfig

@@ -229,6 +229,8 @@ config PCMCIA
 	bool
 	default n
 
+source "drivers/base/Kconfig"
+
 menu "SCSI support"
 
 config SCSI

arch/sh/Kconfig

@@ -767,6 +767,8 @@ source "fs/Kconfig.binfmt"
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

arch/sparc/Kconfig

@@ -319,6 +319,8 @@ config PRINTER
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/video/Kconfig"
 
 source "drivers/mtd/Kconfig"

arch/sparc64/Kconfig

@@ -521,6 +521,8 @@ config WATCHDOG_RIO
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/video/Kconfig"
 
 source "drivers/serial/Kconfig"

arch/um/Kconfig

@@ -171,6 +171,8 @@ endmenu
 
 source "init/Kconfig"
 
+source "drivers/base/Kconfig"
+
 source "arch/um/Kconfig_char"
 
 source "arch/um/Kconfig_block"

arch/v850/Kconfig

@@ -249,6 +249,8 @@ endmenu
 
 #############################################################################
 
+source "drivers/base/Kconfig"
+
 source drivers/mtd/Kconfig
 
 source drivers/parport/Kconfig

arch/x86_64/Kconfig

@@ -397,6 +397,8 @@ config UID16
 
 endmenu
 
+source "drivers/base/Kconfig"
+
 source "drivers/mtd/Kconfig"
 
 source "drivers/parport/Kconfig"

drivers/base/Kconfig

+menu "Generic Driver Options"
+
+config FW_LOADER
+	tristate "Hotplug firmware loading support"
+	---help---
+	  This option is provided for the case where no in-kernel-tree modules
+	  require hotplug firmware loading support, but a module built outside
+	  the kernel tree does.
+
+endmenu

drivers/base/Makefile

@@ -3,4 +3,5 @@
 obj-y			:= core.o sys.o interface.o power.o bus.o \
 			   driver.o class.o platform.o \
 			   cpu.o firmware.o init.o map.o
+obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
 obj-$(CONFIG_NUMA)	+= node.o  memblk.o

drivers/base/firmware_class.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 <asm/hardirq.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");
+
+static int loading_timeout = 10;	/* In seconds */
+
+struct firmware_priv {
+	char fw_id[FIRMWARE_NAME_MAX];
+	struct completion completion;
+	struct bin_attribute attr_data;
+	struct firmware *fw;
+	int loading;
+	int abort;
+	int alloc_size;
+	struct timer_list timeout;
+};
+
+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;
+	char *scratch = buffer;
+
+	if (buffer_size < (FIRMWARE_NAME_MAX + 10))
+		return -ENOMEM;
+	if (num_envp < 1)
+		return -ENOMEM;
+
+	envp[i++] = scratch;
+	scratch += sprintf(scratch, "FIRMWARE=%s", fw_priv->fw_id) + 1;
+	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);
+	return sprintf(buf, "%d\n", fw_priv->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 prev_loading = fw_priv->loading;
+
+	fw_priv->loading = simple_strtol(buf, NULL, 10);
+
+	switch (fw_priv->loading) {
+	case -1:
+		fw_priv->abort = 1;
+		wmb();
+		complete(&fw_priv->completion);
+		break;
+	case 1:
+		kfree(fw_priv->fw->data);
+		fw_priv->fw->data = NULL;
+		fw_priv->fw->size = 0;
+		fw_priv->alloc_size = 0;
+		break;
+	case 0:
+		if (prev_loading == 1)
+			complete(&fw_priv->completion);
+		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 = fw_priv->fw;
+
+	if (offset > fw->size)
+		return 0;
+	if (offset + count > fw->size)
+		count = fw->size - offset;
+
+	memcpy(buffer, fw->data + offset, count);
+	return 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_priv->abort = 1;
+		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 = fw_priv->fw;
+	int retval;
+
+	retval = fw_realloc_buffer(fw_priv, offset + count);
+	if (retval)
+		return retval;
+
+	memcpy(fw->data + offset, buffer, count);
+
+	fw->size = max_t(size_t, offset + count, fw->size);
+
+	return count;
+}
+static struct bin_attribute firmware_attr_data_tmpl = {
+	.attr = {.name = "data", .mode = 0644},
+	.size = 0,
+	.read = firmware_data_read,
+	.write = firmware_data_write,
+};
+
+static void
+fw_class_dev_release(struct class_device *class_dev)
+{
+	kfree(class_dev);
+}
+
+static void
+firmware_class_timeout(u_long data)
+{
+	struct firmware_priv *fw_priv = (struct firmware_priv *) data;
+	fw_priv->abort = 1;
+	wmb();
+	complete(&fw_priv->completion);
+}
+
+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 */
+	strncpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE);
+	class_dev->class_id[BUS_ID_SIZE - 1] = '\0';
+}
+static int
+fw_setup_class_device(struct class_device **class_dev_p,
+		      const char *fw_name, struct device *device)
+{
+	int retval = 0;
+	struct firmware_priv *fw_priv = kmalloc(sizeof (struct firmware_priv),
+						GFP_KERNEL);
+	struct class_device *class_dev = kmalloc(sizeof (struct class_device),
+						 GFP_KERNEL);
+
+	if (!fw_priv || !class_dev) {
+		retval = -ENOMEM;
+		goto error_kfree;
+	}
+	memset(fw_priv, 0, sizeof (*fw_priv));
+	memset(class_dev, 0, sizeof (*class_dev));
+
+	init_completion(&fw_priv->completion);
+	memcpy(&fw_priv->attr_data, &firmware_attr_data_tmpl,
+	       sizeof (firmware_attr_data_tmpl));
+
+	strncpy(&fw_priv->fw_id[0], fw_name, FIRMWARE_NAME_MAX);
+	fw_priv->fw_id[FIRMWARE_NAME_MAX - 1] = '\0';
+
+	fw_setup_class_device_id(class_dev, device);
+	class_dev->dev = device;
+
+	fw_priv->timeout.function = firmware_class_timeout;
+	fw_priv->timeout.data = (u_long) fw_priv;
+	init_timer(&fw_priv->timeout);
+
+	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;
+	}
+
+	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_class_dev;
+	}
+
+	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_remove_data;
+	}
+
+	fw_priv->fw = kmalloc(sizeof (struct firmware), GFP_KERNEL);
+	if (!fw_priv->fw) {
+		printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
+		       __FUNCTION__);
+		retval = -ENOMEM;
+		goto error_remove_loading;
+	}
+	memset(fw_priv->fw, 0, sizeof (*fw_priv->fw));
+
+	goto out;
+
+error_remove_loading:
+	class_device_remove_file(class_dev, &class_device_attr_loading);
+error_remove_data:
+	sysfs_remove_bin_file(&class_dev->kobj, &fw_priv->attr_data);
+error_unreg_class_dev:
+	class_device_unregister(class_dev);
+error_kfree:
+	kfree(fw_priv);
+	kfree(class_dev);
+	*class_dev_p = NULL;
+out:
+	*class_dev_p = class_dev;
+	return retval;
+}
+static void
+fw_remove_class_device(struct class_device *class_dev)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+	class_device_remove_file(class_dev, &class_device_attr_loading);
+	sysfs_remove_bin_file(&class_dev->kobj, &fw_priv->attr_data);
+	class_device_unregister(class_dev);
+}
+
+/** 
+ * 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, const char *name,
+		 struct device *device)
+{
+	struct class_device *class_dev;
+	struct firmware_priv *fw_priv;
+	int retval;
+
+	if (!firmware)
+		return -EINVAL;
+
+	*firmware = NULL;
+
+	retval = fw_setup_class_device(&class_dev, name, device);
+	if (retval)
+		goto out;
+
+	fw_priv = class_get_devdata(class_dev);
+
+	if (loading_timeout) {
+		fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
+		add_timer(&fw_priv->timeout);
+	}
+
+	wait_for_completion(&fw_priv->completion);
+
+	del_timer(&fw_priv->timeout);
+	fw_remove_class_device(class_dev);
+
+	if (fw_priv->fw->size && !fw_priv->abort) {
+		*firmware = fw_priv->fw;
+	} else {
+		retval = -ENOENT;
+		vfree(fw_priv->fw->data);
+		kfree(fw_priv->fw);
+	}
+	kfree(fw_priv);
+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 void
+request_firmware_work_func(void *arg)
+{
+	struct firmware_work *fw_work = arg;
+	const struct firmware *fw;
+	if (!arg)
+		return;
+	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);
+}
+
+/**
+ * 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);
+	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,
+	};
+	INIT_WORK(&fw_work->work, request_firmware_work_func, fw_work);
+
+	schedule_work(&fw_work->work);
+	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__);
+	}
+	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_remove_file(&firmware_class, &class_attr_timeout);
+	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);
+EXPORT_SYMBOL(firmware_class);

include/linux/firmware.h

+#ifndef _LINUX_FIRMWARE_H
+#define _LINUX_FIRMWARE_H
+#include <linux/module.h>
+#include <linux/types.h>
+#define FIRMWARE_NAME_MAX 30 
+struct firmware {
+	size_t size;
+	u8 *data;
+};
+int request_firmware(const struct firmware **fw, const char *name,
+		     struct device *device);
+int request_firmware_nowait(
+	struct module *module,
+	const char *name, struct device *device, void *context,
+	void (*cont)(const struct firmware *fw, void *context));
+
+void release_firmware(const struct firmware *fw);
+void register_firmware(const char *name, const u8 *data, size_t size);
+#endif