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/firmware.h>
  18
  19
  20 MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
  21 MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
  22 MODULE_LICENSE("GPL");
  23
  24 static inline struct class_device *to_class_dev(struct kobject *obj)
  25 {
  26         return container_of(obj,struct class_device,kobj);
  27 }
  28 static inline
  29 struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
  30 {
  31         return container_of(_attr,struct class_device_attribute,attr);
  32 }
  33
  34 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
  35 int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
  36
  37 struct firmware_priv {
  38         char fw_id[FIRMWARE_NAME_MAX];
  39         s32 loading:2;
  40         u32 abort:1;
  41 };
  42
  43 extern struct class firmware_class;
  44
  45 static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
  46 {
  47         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  48         return sprintf(buf, "%d\n", fw_priv->loading);
  49 }
  50 static ssize_t firmware_loading_store(struct class_device *class_dev,
  51                                       const char *buf, size_t count)
  52 {
  53         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  54         int prev_loading = fw_priv->loading;
  55
  56         fw_priv->loading = simple_strtol(buf, NULL, 10);
  57
  58         switch(fw_priv->loading){
  59         case -1:
  60                 /* abort load an panic */
  61                 break;
  62         case 1:
  63                 /* setup load */
  64                 break;
  65         case 0:
  66                 if(prev_loading==1){
  67                         /* finish load and get the device back to working
  68                          * state */
  69                 }
  70                 break;
  71         }
  72
  73         return count;
  74 }
  75 static CLASS_DEVICE_ATTR(loading, 0644,
  76                          firmware_loading_show, firmware_loading_store);
  77
  78 static ssize_t firmware_data_read(struct kobject *kobj,
  79                                   char *buffer, loff_t offset, size_t count)
  80 {
  81         struct class_device *class_dev = to_class_dev(kobj);
  82         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  83
  84         /* read from the devices firmware memory */
  85
  86         return count;
  87 }
  88 static ssize_t firmware_data_write(struct kobject *kobj,
  89                                    char *buffer, loff_t offset, size_t count)
  90 {
  91         struct class_device *class_dev = to_class_dev(kobj);
  92         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
  93
  94         /* write to the devices firmware memory */
  95
  96         return count;
  97 }
  98 static struct bin_attribute firmware_attr_data = {
  99         .attr = {.name = "data", .mode = 0644},
 100         .size = 0,
 101         .read = firmware_data_read,
 102         .write = firmware_data_write,
 103 };
 104 static int fw_setup_class_device(struct class_device *class_dev,
 105                                  const char *fw_name,
 106                                  struct device *device)
 107 {
 108         int retval = 0;
 109         struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
 110                                                 GFP_KERNEL);
 111
 112         if(!fw_priv){
 113                 retval = -ENOMEM;
 114                 goto out;
 115         }
 116         memset(fw_priv, 0, sizeof(*fw_priv));
 117         memset(class_dev, 0, sizeof(*class_dev));
 118
 119         strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
 120         fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
 121
 122         strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
 123         class_dev->class_id[BUS_ID_SIZE-1] = '\0';
 124         class_dev->dev = device;
 125
 126         class_dev->class = &firmware_class,
 127         class_set_devdata(class_dev, fw_priv);
 128         retval = class_device_register(class_dev);
 129         if (retval){
 130                 printk(KERN_ERR "%s: class_device_register failed\n",
 131                        __FUNCTION__);
 132                 goto error_free_fw_priv;
 133         }
 134
 135         retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
 136         if (retval){
 137                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
 138                        __FUNCTION__);
 139                 goto error_unreg_class_dev;
 140         }
 141
 142         retval = class_device_create_file(class_dev,
 143                                           &class_device_attr_loading);
 144         if (retval){
 145                 printk(KERN_ERR "%s: class_device_create_file failed\n",
 146                        __FUNCTION__);
 147                 goto error_remove_data;
 148         }
 149
 150         goto out;
 151
 152 error_remove_data:
 153         sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
 154 error_unreg_class_dev:
 155         class_device_unregister(class_dev);
 156 error_free_fw_priv:
 157         kfree(fw_priv);
 158 out:
 159         return retval;
 160 }
 161 static void fw_remove_class_device(struct class_device *class_dev)
 162 {
 163         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
 164
 165         class_device_remove_file(class_dev, &class_device_attr_loading);
 166         sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
 167         class_device_unregister(class_dev);
 168 }
 169
 170 static struct class_device *class_dev;
 171
 172 static struct device my_device = {
 173         .name      = "Sample Device",
 174         .bus_id    = "my_dev0",
 175 };
 176
 177 static int __init firmware_sample_init(void)
 178 {
 179         int error;
 180
 181         device_initialize(&my_device);
 182         class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
 183         if(!class_dev)
 184                 return -ENOMEM;
 185
 186         error = fw_setup_class_device(class_dev, "my_firmware_image",
 187                                       &my_device);
 188         if(error){
 189                 kfree(class_dev);
 190                 return error;
 191         }
 192         return 0;
 193
 194 }
 195 static void __exit firmware_sample_exit(void)
 196 {
 197         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
 198         fw_remove_class_device(class_dev);
 199         kfree(fw_priv);
 200         kfree(class_dev);
 201 }
 202 module_init(firmware_sample_init);
 203 module_exit(firmware_sample_exit);
 204