Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
124
Documentation/firmware_class/README
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124
Documentation/firmware_class/README
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@@ -0,0 +1,124 @@
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request_firmware() hotplug interface:
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------------------------------------
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Copyright (C) 2003 Manuel Estrada Sainz <ranty@debian.org>
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Why:
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---
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Today, the most extended way to use firmware in the Linux kernel is linking
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it statically in a header file. Which has political and technical issues:
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1) Some firmware is not legal to redistribute.
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2) The firmware occupies memory permanently, even though it often is just
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used once.
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3) Some people, like the Debian crowd, don't consider some firmware free
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enough and remove entire drivers (e.g.: keyspan).
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High level behavior (mixed):
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============================
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kernel(driver): calls request_firmware(&fw_entry, $FIRMWARE, device)
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userspace:
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- /sys/class/firmware/xxx/{loading,data} appear.
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- hotplug gets called with a firmware identifier in $FIRMWARE
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and the usual hotplug environment.
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- hotplug: echo 1 > /sys/class/firmware/xxx/loading
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kernel: Discard any previous partial load.
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userspace:
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- hotplug: cat appropriate_firmware_image > \
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/sys/class/firmware/xxx/data
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kernel: grows a buffer in PAGE_SIZE increments to hold the image as it
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comes in.
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userspace:
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- hotplug: echo 0 > /sys/class/firmware/xxx/loading
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kernel: request_firmware() returns and the driver has the firmware
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image in fw_entry->{data,size}. If something went wrong
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request_firmware() returns non-zero and fw_entry is set to
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NULL.
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kernel(driver): Driver code calls release_firmware(fw_entry) releasing
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the firmware image and any related resource.
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High level behavior (driver code):
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==================================
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if(request_firmware(&fw_entry, $FIRMWARE, device) == 0)
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copy_fw_to_device(fw_entry->data, fw_entry->size);
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release(fw_entry);
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Sample/simple hotplug script:
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============================
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# Both $DEVPATH and $FIRMWARE are already provided in the environment.
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HOTPLUG_FW_DIR=/usr/lib/hotplug/firmware/
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echo 1 > /sys/$DEVPATH/loading
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cat $HOTPLUG_FW_DIR/$FIRMWARE > /sysfs/$DEVPATH/data
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echo 0 > /sys/$DEVPATH/loading
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Random notes:
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============
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- "echo -1 > /sys/class/firmware/xxx/loading" will cancel the load at
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once and make request_firmware() return with error.
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- firmware_data_read() and firmware_loading_show() are just provided
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for testing and completeness, they are not called in normal use.
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- There is also /sys/class/firmware/timeout which holds a timeout in
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seconds for the whole load operation.
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- request_firmware_nowait() is also provided for convenience in
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non-user contexts.
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about in-kernel persistence:
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---------------------------
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Under some circumstances, as explained below, it would be interesting to keep
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firmware images in non-swappable kernel memory or even in the kernel image
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(probably within initramfs).
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Note that this functionality has not been implemented.
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- Why OPTIONAL in-kernel persistence may be a good idea sometimes:
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- If the device that needs the firmware is needed to access the
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filesystem. When upon some error the device has to be reset and the
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firmware reloaded, it won't be possible to get it from userspace.
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e.g.:
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- A diskless client with a network card that needs firmware.
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- The filesystem is stored in a disk behind an scsi device
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that needs firmware.
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- Replacing buggy DSDT/SSDT ACPI tables on boot.
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Note: this would require the persistent objects to be included
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within the kernel image, probably within initramfs.
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And the same device can be needed to access the filesystem or not depending
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on the setup, so I think that the choice on what firmware to make
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persistent should be left to userspace.
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- Why register_firmware()+__init can be useful:
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- For boot devices needing firmware.
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- To make the transition easier:
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The firmware can be declared __init and register_firmware()
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called on module_init. Then the firmware is warranted to be
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there even if "firmware hotplug userspace" is not there yet or
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it doesn't yet provide the needed firmware.
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Once the firmware is widely available in userspace, it can be
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removed from the kernel. Or made optional (CONFIG_.*_FIRMWARE).
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In either case, if firmware hotplug support is there, it can move the
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firmware out of kernel memory into the real filesystem for later
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usage.
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Note: If persistence is implemented on top of initramfs,
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register_firmware() may not be appropriate.
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126
Documentation/firmware_class/firmware_sample_driver.c
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126
Documentation/firmware_class/firmware_sample_driver.c
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/*
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* firmware_sample_driver.c -
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*
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* Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
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*
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* Sample code on how to use request_firmware() from drivers.
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*
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* Note that register_firmware() is currently useless.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include "linux/firmware.h"
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#define WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
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#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
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char __init inkernel_firmware[] = "let's say that this is firmware\n";
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#endif
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static struct device ghost_device = {
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.name = "Ghost Device",
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.bus_id = "ghost0",
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};
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static void sample_firmware_load(char *firmware, int size)
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{
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u8 buf[size+1];
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memcpy(buf, firmware, size);
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buf[size] = '\0';
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printk("firmware_sample_driver: firmware: %s\n", buf);
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}
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static void sample_probe_default(void)
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{
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/* uses the default method to get the firmware */
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const struct firmware *fw_entry;
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printk("firmware_sample_driver: a ghost device got inserted :)\n");
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if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0)
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{
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printk(KERN_ERR
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"firmware_sample_driver: Firmware not available\n");
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return;
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}
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sample_firmware_load(fw_entry->data, fw_entry->size);
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release_firmware(fw_entry);
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/* finish setting up the device */
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}
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static void sample_probe_specific(void)
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{
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/* Uses some specific hotplug support to get the firmware from
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* userspace directly into the hardware, or via some sysfs file */
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/* NOTE: This currently doesn't work */
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printk("firmware_sample_driver: a ghost device got inserted :)\n");
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if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0)
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{
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printk(KERN_ERR
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"firmware_sample_driver: Firmware load failed\n");
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return;
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}
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/* request_firmware blocks until userspace finished, so at
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* this point the firmware should be already in the device */
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/* finish setting up the device */
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}
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static void sample_probe_async_cont(const struct firmware *fw, void *context)
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{
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if(!fw){
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printk(KERN_ERR
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"firmware_sample_driver: firmware load failed\n");
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return;
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}
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printk("firmware_sample_driver: device pointer \"%s\"\n",
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(char *)context);
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sample_firmware_load(fw->data, fw->size);
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}
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static void sample_probe_async(void)
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{
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/* Let's say that I can't sleep */
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int error;
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error = request_firmware_nowait (THIS_MODULE,
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"sample_driver_fw", &ghost_device,
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"my device pointer",
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sample_probe_async_cont);
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if(error){
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printk(KERN_ERR
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"firmware_sample_driver:"
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" request_firmware_nowait failed\n");
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}
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}
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static int sample_init(void)
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{
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#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
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register_firmware("sample_driver_fw", inkernel_firmware,
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sizeof(inkernel_firmware));
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#endif
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device_initialize(&ghost_device);
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/* since there is no real hardware insertion I just call the
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* sample probe functions here */
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sample_probe_specific();
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sample_probe_default();
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sample_probe_async();
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return 0;
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}
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static void __exit sample_exit(void)
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{
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}
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module_init (sample_init);
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module_exit (sample_exit);
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MODULE_LICENSE("GPL");
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204
Documentation/firmware_class/firmware_sample_firmware_class.c
Normal file
204
Documentation/firmware_class/firmware_sample_firmware_class.c
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@@ -0,0 +1,204 @@
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/*
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* firmware_sample_firmware_class.c -
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*
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* Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
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*
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* NOTE: This is just a probe of concept, if you think that your driver would
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* be well served by this mechanism please contact me first.
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*
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* DON'T USE THIS CODE AS IS
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*
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/timer.h>
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#include <linux/firmware.h>
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MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
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MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
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MODULE_LICENSE("GPL");
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static inline struct class_device *to_class_dev(struct kobject *obj)
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{
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return container_of(obj,struct class_device,kobj);
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}
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static inline
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struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
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{
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return container_of(_attr,struct class_device_attribute,attr);
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}
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int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
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int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
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struct firmware_priv {
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char fw_id[FIRMWARE_NAME_MAX];
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s32 loading:2;
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u32 abort:1;
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};
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extern struct class firmware_class;
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static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
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{
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struct firmware_priv *fw_priv = class_get_devdata(class_dev);
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return sprintf(buf, "%d\n", fw_priv->loading);
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}
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static ssize_t firmware_loading_store(struct class_device *class_dev,
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const char *buf, size_t count)
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{
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struct firmware_priv *fw_priv = class_get_devdata(class_dev);
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int prev_loading = fw_priv->loading;
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fw_priv->loading = simple_strtol(buf, NULL, 10);
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switch(fw_priv->loading){
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case -1:
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/* abort load an panic */
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break;
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case 1:
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/* setup load */
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break;
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case 0:
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if(prev_loading==1){
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/* finish load and get the device back to working
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* state */
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}
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break;
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}
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return count;
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}
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static CLASS_DEVICE_ATTR(loading, 0644,
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firmware_loading_show, firmware_loading_store);
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static ssize_t firmware_data_read(struct kobject *kobj,
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char *buffer, loff_t offset, size_t count)
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{
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struct class_device *class_dev = to_class_dev(kobj);
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struct firmware_priv *fw_priv = class_get_devdata(class_dev);
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/* read from the devices firmware memory */
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return count;
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}
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static ssize_t firmware_data_write(struct kobject *kobj,
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char *buffer, loff_t offset, size_t count)
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{
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struct class_device *class_dev = to_class_dev(kobj);
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struct firmware_priv *fw_priv = class_get_devdata(class_dev);
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/* write to the devices firmware memory */
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return count;
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}
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static struct bin_attribute firmware_attr_data = {
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.attr = {.name = "data", .mode = 0644},
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.size = 0,
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.read = firmware_data_read,
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.write = firmware_data_write,
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};
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static int fw_setup_class_device(struct class_device *class_dev,
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const char *fw_name,
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struct device *device)
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{
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int retval = 0;
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struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
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GFP_KERNEL);
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if(!fw_priv){
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retval = -ENOMEM;
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goto out;
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}
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memset(fw_priv, 0, sizeof(*fw_priv));
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memset(class_dev, 0, sizeof(*class_dev));
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strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
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fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
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strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
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class_dev->class_id[BUS_ID_SIZE-1] = '\0';
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class_dev->dev = device;
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class_dev->class = &firmware_class,
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class_set_devdata(class_dev, fw_priv);
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retval = class_device_register(class_dev);
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if (retval){
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printk(KERN_ERR "%s: class_device_register failed\n",
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__FUNCTION__);
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goto error_free_fw_priv;
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}
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retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
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if (retval){
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printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
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__FUNCTION__);
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goto error_unreg_class_dev;
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}
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retval = class_device_create_file(class_dev,
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&class_device_attr_loading);
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if (retval){
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printk(KERN_ERR "%s: class_device_create_file failed\n",
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__FUNCTION__);
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goto error_remove_data;
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}
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goto out;
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error_remove_data:
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sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
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error_unreg_class_dev:
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class_device_unregister(class_dev);
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error_free_fw_priv:
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kfree(fw_priv);
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out:
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return retval;
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}
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static void fw_remove_class_device(struct class_device *class_dev)
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{
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struct firmware_priv *fw_priv = class_get_devdata(class_dev);
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class_device_remove_file(class_dev, &class_device_attr_loading);
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sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
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class_device_unregister(class_dev);
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}
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static struct class_device *class_dev;
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static struct device my_device = {
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.name = "Sample Device",
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.bus_id = "my_dev0",
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};
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static int __init firmware_sample_init(void)
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{
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int error;
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device_initialize(&my_device);
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class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
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if(!class_dev)
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return -ENOMEM;
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error = fw_setup_class_device(class_dev, "my_firmware_image",
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&my_device);
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if(error){
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kfree(class_dev);
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return error;
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}
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return 0;
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}
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static void __exit firmware_sample_exit(void)
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{
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struct firmware_priv *fw_priv = class_get_devdata(class_dev);
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fw_remove_class_device(class_dev);
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kfree(fw_priv);
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kfree(class_dev);
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}
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module_init(firmware_sample_init);
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module_exit(firmware_sample_exit);
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|
16
Documentation/firmware_class/hotplug-script
Normal file
16
Documentation/firmware_class/hotplug-script
Normal file
@@ -0,0 +1,16 @@
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#!/bin/sh
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|
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# Simple hotplug script sample:
|
||||
#
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# Both $DEVPATH and $FIRMWARE are already provided in the environment.
|
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|
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HOTPLUG_FW_DIR=/usr/lib/hotplug/firmware/
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echo 1 > /sys/$DEVPATH/loading
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cat $HOTPLUG_FW_DIR/$FIRMWARE > /sys/$DEVPATH/data
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echo 0 > /sys/$DEVPATH/loading
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# To cancel the load in case of error:
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#
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# echo -1 > /sys/$DEVPATH/loading
|
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#
|
Reference in New Issue
Block a user