dell_rbu.c

对于那些带有区码限制的DVD光驱

	 * Re-initialize the rbu_data variables after a free
	 */
	rbu_data.image_update_ordernum = -1;
	rbu_data.image_update_buffer = NULL;
	rbu_data.image_update_buffer_size = 0;
	rbu_data.bios_image_size = 0;
	rbu_data.dma_alloc = 0;
}

/*
 * img_update_realloc: This function allocates the contiguous pages to
 * accommodate the requested size of data. The memory address and size
 * values are stored globally and on every call to this function the new
 * size is checked to see if more data is required than the existing size.
 * If true the previous memory is freed and new allocation is done to
 * accommodate the new size. If the incoming size is less then than the
 * already allocated size, then that memory is reused. This function is
 * called with lock held and returns with lock held.
 */
static int img_update_realloc(unsigned long size)
{
	unsigned char *image_update_buffer = NULL;
	unsigned long rc;
	unsigned long img_buf_phys_addr;
	int ordernum;
	int dma_alloc = 0;

	/*
	 * check if the buffer of sufficient size has been
	 * already allocated
	 */
	if (rbu_data.image_update_buffer_size >= size) {
		/*
		 * check for corruption
		 */
		if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
			printk(KERN_ERR "dell_rbu:%s: corruption "
				"check failed\n", __FUNCTION__);
			return -EINVAL;
		}
		/*
		 * we have a valid pre-allocated buffer with
		 * sufficient size
		 */
		return 0;
	}

	/*
	 * free any previously allocated buffer
	 */
	img_update_free();

	spin_unlock(&rbu_data.lock);

	ordernum = get_order(size);
	image_update_buffer =
		(unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);

	img_buf_phys_addr =
		(unsigned long) virt_to_phys(image_update_buffer);

	if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
		free_pages((unsigned long) image_update_buffer, ordernum);
		ordernum = -1;
		image_update_buffer = dma_alloc_coherent(NULL, size,
			&dell_rbu_dmaaddr, GFP_KERNEL);
		dma_alloc = 1;
	}

	spin_lock(&rbu_data.lock);

	if (image_update_buffer != NULL) {
		rbu_data.image_update_buffer = image_update_buffer;
		rbu_data.image_update_buffer_size = size;
		rbu_data.bios_image_size =
			rbu_data.image_update_buffer_size;
		rbu_data.image_update_ordernum = ordernum;
		rbu_data.dma_alloc = dma_alloc;
		rc = 0;
	} else {
		pr_debug("Not enough memory for image update:"
			"size = %ld\n", size);
		rc = -ENOMEM;
	}

	return rc;
}

static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
{
	int retval;
	size_t bytes_left;
	size_t data_length;
	char *ptempBuf = buffer;

	/* check to see if we have something to return */
	if (rbu_data.num_packets == 0) {
		pr_debug("read_packet_data: no packets written\n");
		retval = -ENOMEM;
		goto read_rbu_data_exit;
	}

	if (pos > rbu_data.imagesize) {
		retval = 0;
		printk(KERN_WARNING "dell_rbu:read_packet_data: "
			"data underrun\n");
		goto read_rbu_data_exit;
	}

	bytes_left = rbu_data.imagesize - pos;
	data_length = min(bytes_left, count);

	if ((retval = packet_read_list(ptempBuf, &data_length)) < 0)
		goto read_rbu_data_exit;

	if ((pos + count) > rbu_data.imagesize) {
		rbu_data.packet_read_count = 0;
		/* this was the last copy */
		retval = bytes_left;
	} else
		retval = count;

      read_rbu_data_exit:
	return retval;
}

static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
{
	unsigned char *ptemp = NULL;
	size_t bytes_left = 0;
	size_t data_length = 0;
	ssize_t ret_count = 0;

	/* check to see if we have something to return */
	if ((rbu_data.image_update_buffer == NULL) ||
		(rbu_data.bios_image_size == 0)) {
		pr_debug("read_rbu_data_mono: image_update_buffer %p ,"
			"bios_image_size %lu\n",
			rbu_data.image_update_buffer,
			rbu_data.bios_image_size);
		ret_count = -ENOMEM;
		goto read_rbu_data_exit;
	}

	if (pos > rbu_data.bios_image_size) {
		ret_count = 0;
		goto read_rbu_data_exit;
	}

	bytes_left = rbu_data.bios_image_size - pos;
	data_length = min(bytes_left, count);

	ptemp = rbu_data.image_update_buffer;
	memcpy(buffer, (ptemp + pos), data_length);

	if ((pos + count) > rbu_data.bios_image_size)
		/* this was the last copy */
		ret_count = bytes_left;
	else
		ret_count = count;
      read_rbu_data_exit:
	return ret_count;
}

static ssize_t read_rbu_data(struct kobject *kobj, char *buffer,
	loff_t pos, size_t count)
{
	ssize_t ret_count = 0;

	spin_lock(&rbu_data.lock);

	if (!strcmp(image_type, "mono"))
		ret_count = read_rbu_mono_data(buffer, pos, count);
	else if (!strcmp(image_type, "packet"))
		ret_count = read_packet_data(buffer, pos, count);
	else
		pr_debug("read_rbu_data: invalid image type specified\n");

	spin_unlock(&rbu_data.lock);
	return ret_count;
}

static void callbackfn_rbu(const struct firmware *fw, void *context)
{
	int rc = 0;

	if (!fw || !fw->size) {
		rbu_data.entry_created = 0;
		return;
	}

	spin_lock(&rbu_data.lock);
	if (!strcmp(image_type, "mono")) {
		if (!img_update_realloc(fw->size))
			memcpy(rbu_data.image_update_buffer,
				fw->data, fw->size);
	} else if (!strcmp(image_type, "packet")) {
		/*
		 * we need to free previous packets if a
		 * new hunk of packets needs to be downloaded
		 */
		packet_empty_list();
		if (packetize_data(fw->data, fw->size))
			/* Incase something goes wrong when we are
			 * in middle of packetizing the data, we
			 * need to free up whatever packets might
			 * have been created before we quit.
			 */
			packet_empty_list();
	} else
		pr_debug("invalid image type specified.\n");
	spin_unlock(&rbu_data.lock);

	rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
		"dell_rbu", &rbu_device->dev, &context, callbackfn_rbu);
	if (rc)
		printk(KERN_ERR
			"dell_rbu:%s request_firmware_nowait failed"
			" %d\n", __FUNCTION__, rc);
	else
		rbu_data.entry_created = 1;
}

static ssize_t read_rbu_image_type(struct kobject *kobj, char *buffer,
	loff_t pos, size_t count)
{
	int size = 0;
	if (!pos)
		size = sprintf(buffer, "%s\n", image_type);
	return size;
}

static ssize_t write_rbu_image_type(struct kobject *kobj, char *buffer,
	loff_t pos, size_t count)
{
	int rc = count;
	int req_firm_rc = 0;
	int i;
	spin_lock(&rbu_data.lock);
	/*
	 * Find the first newline or space
	 */
	for (i = 0; i < count; ++i)
		if (buffer[i] == '\n' || buffer[i] == ' ') {
			buffer[i] = '\0';
			break;
		}
	if (i == count)
		buffer[count] = '\0';

	if (strstr(buffer, "mono"))
		strcpy(image_type, "mono");
	else if (strstr(buffer, "packet"))
		strcpy(image_type, "packet");
	else if (strstr(buffer, "init")) {
		/*
		 * If due to the user error the driver gets in a bad
		 * state where even though it is loaded , the
		 * /sys/class/firmware/dell_rbu entries are missing.
		 * to cover this situation the user can recreate entries
		 * by writing init to image_type.
		 */
		if (!rbu_data.entry_created) {
			spin_unlock(&rbu_data.lock);
			req_firm_rc = request_firmware_nowait(THIS_MODULE,
				FW_ACTION_NOHOTPLUG, "dell_rbu",
				&rbu_device->dev, &context,
				callbackfn_rbu);
			if (req_firm_rc) {
				printk(KERN_ERR
					"dell_rbu:%s request_firmware_nowait"
					" failed %d\n", __FUNCTION__, rc);
				rc = -EIO;
			} else
				rbu_data.entry_created = 1;

			spin_lock(&rbu_data.lock);
		}
	} else {
		printk(KERN_WARNING "dell_rbu: image_type is invalid\n");
		spin_unlock(&rbu_data.lock);
		return -EINVAL;
	}

	/* we must free all previous allocations */
	packet_empty_list();
	img_update_free();
	spin_unlock(&rbu_data.lock);

	return rc;
}

static ssize_t read_rbu_packet_size(struct kobject *kobj, char *buffer,
	loff_t pos, size_t count)
{
	int size = 0;
	if (!pos) {
		spin_lock(&rbu_data.lock);
		size = sprintf(buffer, "%lu\n", rbu_data.packetsize);
		spin_unlock(&rbu_data.lock);
	}
	return size;
}

static ssize_t write_rbu_packet_size(struct kobject *kobj, char *buffer,
	loff_t pos, size_t count)
{
	unsigned long temp;
	spin_lock(&rbu_data.lock);
	packet_empty_list();
	sscanf(buffer, "%lu", &temp);
	if (temp < 0xffffffff)
		rbu_data.packetsize = temp;

	spin_unlock(&rbu_data.lock);
	return count;
}

static struct bin_attribute rbu_data_attr = {
	.attr = {.name = "data",.owner = THIS_MODULE,.mode = 0444},
	.read = read_rbu_data,
};

static struct bin_attribute rbu_image_type_attr = {
	.attr = {.name = "image_type",.owner = THIS_MODULE,.mode = 0644},
	.read = read_rbu_image_type,
	.write = write_rbu_image_type,
};

static struct bin_attribute rbu_packet_size_attr = {
	.attr = {.name = "packet_size",.owner = THIS_MODULE,.mode = 0644},
	.read = read_rbu_packet_size,
	.write = write_rbu_packet_size,
};

static int __init dcdrbu_init(void)
{
	int rc = 0;
	spin_lock_init(&rbu_data.lock);

	init_packet_head();
	rbu_device =
		platform_device_register_simple("dell_rbu", -1, NULL, 0);
	if (!rbu_device) {
		printk(KERN_ERR
			"dell_rbu:%s:platform_device_register_simple "
			"failed\n", __FUNCTION__);
		return -EIO;
	}

	sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
	sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
	sysfs_create_bin_file(&rbu_device->dev.kobj,
		&rbu_packet_size_attr);

	rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
		"dell_rbu", &rbu_device->dev, &context, callbackfn_rbu);
	if (rc)
		printk(KERN_ERR "dell_rbu:%s:request_firmware_nowait"
			" failed %d\n", __FUNCTION__, rc);
	else
		rbu_data.entry_created = 1;

	return rc;

}

static __exit void dcdrbu_exit(void)
{
	spin_lock(&rbu_data.lock);
	packet_empty_list();
	img_update_free();
	spin_unlock(&rbu_data.lock);
	platform_device_unregister(rbu_device);
}

module_exit(dcdrbu_exit);
module_init(dcdrbu_init);

/* vim:noet:ts=8:sw=8
*/