[ALSA] als4000 - Add PM support
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / Documentation / firmware_class / firmware_sample_driver.c
blobd3ad2c24490aa4361ad83d841aca57607f83e5db
1 /*
2 * firmware_sample_driver.c -
4 * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
6 * Sample code on how to use request_firmware() from drivers.
8 * Note that register_firmware() is currently useless.
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/device.h>
16 #include <linux/string.h>
18 #include "linux/firmware.h"
20 #define WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
21 #ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
22 char __init inkernel_firmware[] = "let's say that this is firmware\n";
23 #endif
25 static struct device ghost_device = {
26 .name = "Ghost Device",
27 .bus_id = "ghost0",
31 static void sample_firmware_load(char *firmware, int size)
33 u8 buf[size+1];
34 memcpy(buf, firmware, size);
35 buf[size] = '\0';
36 printk(KERN_INFO "firmware_sample_driver: firmware: %s\n", buf);
39 static void sample_probe_default(void)
41 /* uses the default method to get the firmware */
42 const struct firmware *fw_entry;
43 printk(KERN_INFO "firmware_sample_driver: a ghost device got inserted :)\n");
45 if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0)
47 printk(KERN_ERR
48 "firmware_sample_driver: Firmware not available\n");
49 return;
52 sample_firmware_load(fw_entry->data, fw_entry->size);
54 release_firmware(fw_entry);
56 /* finish setting up the device */
58 static void sample_probe_specific(void)
60 /* Uses some specific hotplug support to get the firmware from
61 * userspace directly into the hardware, or via some sysfs file */
63 /* NOTE: This currently doesn't work */
65 printk(KERN_INFO "firmware_sample_driver: a ghost device got inserted :)\n");
67 if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0)
69 printk(KERN_ERR
70 "firmware_sample_driver: Firmware load failed\n");
71 return;
74 /* request_firmware blocks until userspace finished, so at
75 * this point the firmware should be already in the device */
77 /* finish setting up the device */
79 static void sample_probe_async_cont(const struct firmware *fw, void *context)
81 if(!fw){
82 printk(KERN_ERR
83 "firmware_sample_driver: firmware load failed\n");
84 return;
87 printk(KERN_INFO "firmware_sample_driver: device pointer \"%s\"\n",
88 (char *)context);
89 sample_firmware_load(fw->data, fw->size);
91 static void sample_probe_async(void)
93 /* Let's say that I can't sleep */
94 int error;
95 error = request_firmware_nowait (THIS_MODULE,
96 "sample_driver_fw", &ghost_device,
97 "my device pointer",
98 sample_probe_async_cont);
99 if(error){
100 printk(KERN_ERR
101 "firmware_sample_driver:"
102 " request_firmware_nowait failed\n");
106 static int sample_init(void)
108 #ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
109 register_firmware("sample_driver_fw", inkernel_firmware,
110 sizeof(inkernel_firmware));
111 #endif
112 device_initialize(&ghost_device);
113 /* since there is no real hardware insertion I just call the
114 * sample probe functions here */
115 sample_probe_specific();
116 sample_probe_default();
117 sample_probe_async();
118 return 0;
120 static void __exit sample_exit(void)
124 module_init (sample_init);
125 module_exit (sample_exit);
127 MODULE_LICENSE("GPL");