samples/firmware_class/firmware_sample_driver.c

   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
  17 static struct device ghost_device = {
  18         .bus_id    = "ghost0",
  19 };
  20
  21
  22 static 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
  30 static 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
  53 static 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
  77 static 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
  90 static 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
 103 static 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
 114 static void __exit sample_exit(void)
 115 {
 116 }
 117
 118 module_init(sample_init);
 119 module_exit(sample_exit);
 120
 121 MODULE_LICENSE("GPL");