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 <linux/slab.h>
  18 #include <linux/string.h>
  19 #include <linux/firmware.h>
  20
  21
  22 MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
  23 MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
  24 MODULE_LICENSE("GPL");
  25
  26 static inline struct class_device *to_class_dev(struct kobject *obj)
  27 {
  28         return container_of(obj,struct class_device,kobj);
  29 }
  30 static inline
  31 struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
  32 {
  33         return container_of(_attr,struct class_device_attribute,attr);
  34 }
  35
  36 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
  37 int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
  38
  39 struct firmware_priv {
  40         char fw_id[FIRMWARE_NAME_MAX];
  41         s32 loading:2;
  42         u32 abort:1;
  43 };
  44
  45 extern struct class firmware_class;
  46
  47 static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
  48 {
  49         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  50         return sprintf(buf, "%d\n", fw_priv->loading);
  51 }
  52 static ssize_t firmware_loading_store(struct class_device *class_dev,
  53                                       const char *buf, size_t count)
  54 {
  55         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  56         int prev_loading = fw_priv->loading;
  57
  58         fw_priv->loading = simple_strtol(buf, NULL, 10);
  59
  60         switch(fw_priv->loading){
  61         case -1:
  62                 /* abort load an panic */
  63                 break;
  64         case 1:
  65                 /* setup load */
  66                 break;
  67         case 0:
  68                 if(prev_loading==1){
  69                         /* finish load and get the device back to working
  70                          * state */
  71                 }
  72                 break;
  73         }
  74
  75         return count;
  76 }
  77 static CLASS_DEVICE_ATTR(loading, 0644,
  78                          firmware_loading_show, firmware_loading_store);
  79
  80 static ssize_t firmware_data_read(struct kobject *kobj,
  81                                   char *buffer, loff_t offset, size_t count)
  82 {
  83         struct class_device *class_dev = to_class_dev(kobj);
  84         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  85
  86         /* read from the devices firmware memory */
  87
  88         return count;
  89 }
  90 static ssize_t firmware_data_write(struct kobject *kobj,
  91                                    char *buffer, loff_t offset, size_t count)
  92 {
  93         struct class_device *class_dev = to_class_dev(kobj);
  94         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  95
  96         /* write to the devices firmware memory */
  97
  98         return count;
  99 }
 100 static struct bin_attribute firmware_attr_data = {
 101         .attr = {.name = "data", .mode = 0644},
 102         .size = 0,
 103         .read = firmware_data_read,
 104         .write = firmware_data_write,
 105 };
 106 static int fw_setup_class_device(struct class_device *class_dev,
 107                                  const char *fw_name,
 108                                  struct device *device)
 109 {
 110         int retval = 0;
 111         struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
 112                                                 GFP_KERNEL);
 113
 114         if(!fw_priv){
 115                 retval = -ENOMEM;
 116                 goto out;
 117         }
 118         memset(fw_priv, 0, sizeof(*fw_priv));
 119         memset(class_dev, 0, sizeof(*class_dev));
 120
 121         strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
 122         fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
 123
 124         strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
 125         class_dev->class_id[BUS_ID_SIZE-1] = '\0';
 126         class_dev->dev = device;
 127
 128         class_dev->class = &firmware_class,
 129         class_set_devdata(class_dev, fw_priv);
 130         retval = class_device_register(class_dev);
 131         if (retval){
 132                 printk(KERN_ERR "%s: class_device_register failed\n",
 133                        __FUNCTION__);
 134                 goto error_free_fw_priv;
 135         }
 136
 137         retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
 138         if (retval){
 139                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
 140                        __FUNCTION__);
 141                 goto error_unreg_class_dev;
 142         }
 143
 144         retval = class_device_create_file(class_dev,
 145                                           &class_device_attr_loading);
 146         if (retval){
 147                 printk(KERN_ERR "%s: class_device_create_file failed\n",
 148                        __FUNCTION__);
 149                 goto error_remove_data;
 150         }
 151
 152         goto out;
 153
 154 error_remove_data:
 155         sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
 156 error_unreg_class_dev:
 157         class_device_unregister(class_dev);
 158 error_free_fw_priv:
 159         kfree(fw_priv);
 160 out:
 161         return retval;
 162 }
 163 static void fw_remove_class_device(struct class_device *class_dev)
 164 {
 165         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
 166
 167         class_device_remove_file(class_dev, &class_device_attr_loading);
 168         sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
 169         class_device_unregister(class_dev);
 170 }
 171
 172 static struct class_device *class_dev;
 173
 174 static struct device my_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