kernel/linux/Documentation/firmware_class/firmware_sample_firmware_class.c

   1 /*
   2  * firmware_sample_firmware_class.c -
   3  *
   4  * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
   5  *
   6  * NOTE: This is just a probe of concept, if you think that your driver would
   7  * be well served by this mechanism please contact me first.
   8  *
   9  * DON'T USE THIS CODE AS IS
  10  *
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/timer.h>
  17 #include <asm/hardirq.h>
  18
  19 #include "linux/firmware.h"
  20
  21 MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
  22 MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
  23 MODULE_LICENSE("GPL");
  24
  25 static inline struct class_device *to_class_dev(struct kobject *obj)
  26 {
  27         return container_of(obj,struct class_device,kobj);
  28 }
  29 static inline
  30 struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
  31 {
  32         return container_of(_attr,struct class_device_attribute,attr);
  33 }
  34
  35 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
  36 int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
  37
  38 struct firmware_priv {
  39         char fw_id[FIRMWARE_NAME_MAX];
  40         s32 loading:2;
  41         u32 abort:1;
  42 };
  43
  44 extern struct class firmware_class;
  45
  46 static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
  47 {
  48         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  49         return sprintf(buf, "%d\n", fw_priv->loading);
  50 }
  51 static ssize_t firmware_loading_store(struct class_device *class_dev,
  52                                       const char *buf, size_t count)
  53 {
  54         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  55         int prev_loading = fw_priv->loading;
  56
  57         fw_priv->loading = simple_strtol(buf, NULL, 10);
  58
  59         switch(fw_priv->loading){
  60         case -1:
  61                 /* abort load an panic */
  62                 break;
  63         case 1:
  64                 /* setup load */
  65                 break;
  66         case 0:
  67                 if(prev_loading==1){
  68                         /* finish load and get the device back to working
  69                          * state */
  70                 }
  71                 break;
  72         }
  73
  74         return count;
  75 }
  76 static CLASS_DEVICE_ATTR(loading, 0644,
  77                          firmware_loading_show, firmware_loading_store);
  78
  79 static ssize_t firmware_data_read(struct kobject *kobj,
  80                                   char *buffer, loff_t offset, size_t count)
  81 {
  82         struct class_device *class_dev = to_class_dev(kobj);
  83         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  84
  85         /* read from the devices firmware memory */
  86
  87         return count;
  88 }
  89 static ssize_t firmware_data_write(struct kobject *kobj,
  90                                    char *buffer, loff_t offset, size_t count)
  91 {
  92         struct class_device *class_dev = to_class_dev(kobj);
  93         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  94
  95         /* write to the devices firmware memory */
  96
  97         return count;
  98 }
  99 static struct bin_attribute firmware_attr_data = {
 100         .attr = {.name = "data", .mode = 0644},
 101         .size = 0,
 102         .read = firmware_data_read,
 103         .write = firmware_data_write,
 104 };
 105 static int fw_setup_class_device(struct class_device *class_dev,
 106                                  const char *fw_name,
 107                                  struct device *device)
 108 {
 109         int retval = 0;
 110         struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
 111                                                 GFP_KERNEL);
 112
 113         if(!fw_priv){
 114                 retval = -ENOMEM;
 115                 goto out;
 116         }
 117         memset(fw_priv, 0, sizeof(*fw_priv));
 118         memset(class_dev, 0, sizeof(*class_dev));
 119
 120         strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
 121         fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
 122
 123         strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
 124         class_dev->class_id[BUS_ID_SIZE-1] = '\0';
 125         class_dev->dev = device;
 126
 127         class_dev->class = &firmware_class,
 128         class_set_devdata(class_dev, fw_priv);
 129         retval = class_device_register(class_dev);
 130         if (retval){
 131                 printk(KERN_ERR "%s: class_device_register failed\n",
 132                        __FUNCTION__);
 133                 goto error_free_fw_priv;
 134         }
 135
 136         retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
 137         if (retval){
 138                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
 139                        __FUNCTION__);
 140                 goto error_unreg_class_dev;
 141         }
 142
 143         retval = class_device_create_file(class_dev,
 144                                           &class_device_attr_loading);
 145         if (retval){
 146                 printk(KERN_ERR "%s: class_device_create_file failed\n",
 147                        __FUNCTION__);
 148                 goto error_remove_data;
 149         }
 150
 151         goto out;
 152
 153 error_remove_data:
 154         sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
 155 error_unreg_class_dev:
 156         class_device_unregister(class_dev);
 157 error_free_fw_priv:
 158         kfree(fw_priv);
 159 out:
 160         return retval;
 161 }
 162 static void fw_remove_class_device(struct class_device *class_dev)
 163 {
 164         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
 165
 166         class_device_remove_file(class_dev, &class_device_attr_loading);
 167         sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
 168         class_device_unregister(class_dev);
 169 }
 170
 171 static struct class_device *class_dev;
 172
 173 static struct device my_device = {
 174         .name      = "Sample Device",
 175         .bus_id    = "my_dev0",
 176 };
 177
 178 static int __init firmware_sample_init(void)
 179 {
 180         int error;
 181
 182         device_initialize(&my_device);
 183         class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
 184         if(!class_dev)
 185                 return -ENOMEM;
 186
 187         error = fw_setup_class_device(class_dev, "my_firmware_image",
 188                                       &my_device);
 189         if(error){
 190                 kfree(class_dev);
 191                 return error;
 192         }
 193         return 0;
 194
 195 }
 196 static void __exit firmware_sample_exit(void)
 197 {
 198         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
 199         fw_remove_class_device(class_dev);
 200         kfree(fw_priv);
 201         kfree(class_dev);
 202 }
 203 module_init(firmware_sample_init);
 204 module_exit(firmware_sample_exit);
 205