linux/samples/firmware_class/firmware_sample_driver.c
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   1/*
   2 * firmware_sample_driver.c -
   3 *
   4 * Copyright (c) 2003 Manuel Estrada Sainz
   5 *
   6 * Sample code on how to use request_firmware() from drivers.
   7 *
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/kernel.h>
  12#include <linux/init.h>
  13#include <linux/device.h>
  14#include <linux/string.h>
  15#include <linux/firmware.h>
  16
  17static struct device ghost_device = {
  18        .bus_id    = "ghost0",
  19};
  20
  21
  22static void sample_firmware_load(char *firmware, int size)
  23{
  24        u8 buf[size+1];
  25        memcpy(buf, firmware, size);
  26        buf[size] = '\0';
  27        printk(KERN_INFO "firmware_sample_driver: firmware: %s\n", buf);
  28}
  29
  30static void sample_probe_default(void)
  31{
  32        /* uses the default method to get the firmware */
  33        const struct firmware *fw_entry;
  34        int retval;
  35
  36        printk(KERN_INFO "firmware_sample_driver: "
  37                "a ghost device got inserted :)\n");
  38
  39        retval = request_firmware(&fw_entry, "sample_driver_fw", &ghost_device);
  40        if (retval) {
  41                printk(KERN_ERR
  42                       "firmware_sample_driver: Firmware not available\n");
  43                return;
  44        }
  45
  46        sample_firmware_load(fw_entry->data, fw_entry->size);
  47
  48        release_firmware(fw_entry);
  49
  50        /* finish setting up the device */
  51}
  52
  53static void sample_probe_specific(void)
  54{
  55        int retval;
  56        /* Uses some specific hotplug support to get the firmware from
  57         * userspace  directly into the hardware, or via some sysfs file */
  58
  59        /* NOTE: This currently doesn't work */
  60
  61        printk(KERN_INFO "firmware_sample_driver: "
  62                "a ghost device got inserted :)\n");
  63
  64        retval = request_firmware(NULL, "sample_driver_fw", &ghost_device);
  65        if (retval) {
  66                printk(KERN_ERR
  67                       "firmware_sample_driver: Firmware load failed\n");
  68                return;
  69        }
  70
  71        /* request_firmware blocks until userspace finished, so at
  72         * this point the firmware should be already in the device */
  73
  74        /* finish setting up the device */
  75}
  76
  77static void sample_probe_async_cont(const struct firmware *fw, void *context)
  78{
  79        if (!fw) {
  80                printk(KERN_ERR
  81                       "firmware_sample_driver: firmware load failed\n");
  82                return;
  83        }
  84
  85        printk(KERN_INFO "firmware_sample_driver: device pointer \"%s\"\n",
  86               (char *)context);
  87        sample_firmware_load(fw->data, fw->size);
  88}
  89
  90static void sample_probe_async(void)
  91{
  92        /* Let's say that I can't sleep */
  93        int error;
  94        error = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
  95                                        "sample_driver_fw", &ghost_device,
  96                                        "my device pointer",
  97                                        sample_probe_async_cont);
  98        if (error)
  99                printk(KERN_ERR "firmware_sample_driver:"
 100                       " request_firmware_nowait failed\n");
 101}
 102
 103static int sample_init(void)
 104{
 105        device_initialize(&ghost_device);
 106        /* since there is no real hardware insertion I just call the
 107         * sample probe functions here */
 108        sample_probe_specific();
 109        sample_probe_default();
 110        sample_probe_async();
 111        return 0;
 112}
 113
 114static void __exit sample_exit(void)
 115{
 116}
 117
 118module_init(sample_init);
 119module_exit(sample_exit);
 120
 121MODULE_LICENSE("GPL");
 122
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