root/samples/firmware_class/firmware_sample_firmware_class.c

DEFINITIONS

1. to_class_dev
2. to_class_dev_attr
3. firmware_loading_show
4. firmware_loading_store
5. firmware_data_read
6. firmware_data_write
7. fw_setup_class_device
8. fw_remove_class_device
9. firmware_sample_init
10. firmware_sample_exit

/*
 * firmware_sample_firmware_class.c -
 *
 * Copyright (c) 2003 Manuel Estrada Sainz
 *
 * NOTE: This is just a probe of concept, if you think that your driver would
 * be well served by this mechanism please contact me first.
 *
 * DON'T USE THIS CODE AS IS
 *
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/firmware.h>


MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
MODULE_LICENSE("GPL");

static inline struct class_device *to_class_dev(struct kobject *obj)
{
        return container_of(obj, struct class_device, kobj);
}

static inline
struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
{
        return container_of(_attr, struct class_device_attribute, attr);
}

struct firmware_priv {
        char fw_id[FIRMWARE_NAME_MAX];
        s32 loading:2;
        u32 abort:1;
};

static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
{
        struct firmware_priv *fw_priv = class_get_devdata(class_dev);
        return sprintf(buf, "%d\n", fw_priv->loading);
}

static ssize_t firmware_loading_store(struct class_device *class_dev,
                                      const char *buf, size_t count)
{
        struct firmware_priv *fw_priv = class_get_devdata(class_dev);
        int prev_loading = fw_priv->loading;

        fw_priv->loading = simple_strtol(buf, NULL, 10);

        switch (fw_priv->loading) {
        case -1:
                /* abort load an panic */
                break;
        case 1:
                /* setup load */
                break;
        case 0:
                if (prev_loading == 1) {
                        /* finish load and get the device back to working
                         * state */
                }
                break;
        }

        return count;
}
static CLASS_DEVICE_ATTR(loading, 0644,
                         firmware_loading_show, firmware_loading_store);

static ssize_t firmware_data_read(struct kobject *kobj,
                                  struct bin_attribute *bin_attr,
                                  char *buffer, loff_t offset, size_t count)
{
        struct class_device *class_dev = to_class_dev(kobj);
        struct firmware_priv *fw_priv = class_get_devdata(class_dev);

        /* read from the devices firmware memory */

        return count;
}
static ssize_t firmware_data_write(struct kobject *kobj,
                                   struct bin_attribute *bin_attr,
                                   char *buffer, loff_t offset, size_t count)
{
        struct class_device *class_dev = to_class_dev(kobj);
        struct firmware_priv *fw_priv = class_get_devdata(class_dev);

        /* write to the devices firmware memory */

        return count;
}
static struct bin_attribute firmware_attr_data = {
        .attr = {.name = "data", .mode = 0644},
        .size = 0,
        .read = firmware_data_read,
        .write = firmware_data_write,
};
static int fw_setup_class_device(struct class_device *class_dev,
                                 const char *fw_name,
                                 struct device *device)
{
        int retval;
        struct firmware_priv *fw_priv;

        fw_priv = kzalloc(sizeof(struct firmware_priv), GFP_KERNEL);
        if (!fw_priv) {
                retval = -ENOMEM;
                goto out;
        }

        memset(class_dev, 0, sizeof(*class_dev));

        strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
        fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';

        strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
        class_dev->class_id[BUS_ID_SIZE-1] = '\0';
        class_dev->dev = device;

        class_dev->class = &firmware_class;
        class_set_devdata(class_dev, fw_priv);
        retval = class_device_register(class_dev);
        if (retval) {
                printk(KERN_ERR "%s: class_device_register failed\n",
                       __func__);
                goto error_free_fw_priv;
        }

        retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
        if (retval) {
                printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
                       __func__);
                goto error_unreg_class_dev;
        }

        retval = class_device_create_file(class_dev,
                                          &class_device_attr_loading);
        if (retval) {
                printk(KERN_ERR "%s: class_device_create_file failed\n",
                       __func__);
                goto error_remove_data;
        }

        goto out;

error_remove_data:
        sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
error_unreg_class_dev:
        class_device_unregister(class_dev);
error_free_fw_priv:
        kfree(fw_priv);
out:
        return retval;
}
static void fw_remove_class_device(struct class_device *class_dev)
{
        struct firmware_priv *fw_priv = class_get_devdata(class_dev);

        class_device_remove_file(class_dev, &class_device_attr_loading);
        sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
        class_device_unregister(class_dev);
}

static struct class_device *class_dev;

static struct device my_device = {
        .bus_id    = "my_dev0",
};

static int __init firmware_sample_init(void)
{
        int error;

        device_initialize(&my_device);
        class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
        if (!class_dev)
                return -ENOMEM;

        error = fw_setup_class_device(class_dev, "my_firmware_image",
                                      &my_device);
        if (error) {
                kfree(class_dev);
                return error;
        }
        return 0;

}
static void __exit firmware_sample_exit(void)
{
        struct firmware_priv *fw_priv = class_get_devdata(class_dev);
        fw_remove_class_device(class_dev);
        kfree(fw_priv);
        kfree(class_dev);
}

module_init(firmware_sample_init);
module_exit(firmware_sample_exit);