[PATCH] Use of the new attribute modifiers on the 53c700

The attached patch illustrates how the new attribute functions can be
used.

The 53c700 modifies the queue_depth attribute so it can be set by the
root user, and also adds a new active_tags attribute which may be used
to obtain the information it currently puts out via its proc interface.

This achieves all I think we really need, which is the ability to have
LLDs provide their own routines for setting the default attributes.

drivers/scsi/53c700.c

@@ -173,6 +173,8 @@ STATIC void NCR_700_chip_reset(struct Scsi_Host *host);
 STATIC int NCR_700_slave_configure(Scsi_Device *SDpnt);
 STATIC void NCR_700_slave_destroy(Scsi_Device *SDpnt);
 
+static struct device_attribute **NCR_700_dev_attrs = NULL;
+
 static char *NCR_700_phase[] = {
 	"",
 	"after selection",
@@ -247,6 +249,9 @@ NCR_700_detect(Scsi_Host_Template *tpnt,
 	static int banner = 0;
 	int j;
 
+	if(tpnt->sdev_attrs == NULL)
+		tpnt->sdev_attrs = NCR_700_dev_attrs;
+
 	memory = dma_alloc_noncoherent(hostdata->dev, TOTAL_MEM_SIZE,
 				       &pScript, GFP_KERNEL);
 	if(memory == NULL) {
@@ -2015,6 +2020,55 @@ NCR_700_slave_destroy(Scsi_Device *SDp)
 	/* to do here: deallocate memory */
 }
 
+static ssize_t
+NCR_700_store_queue_depth(struct device *dev, const char *buf, size_t count)
+{
+	int depth;
+
+	struct scsi_device *SDp = to_scsi_device(dev);
+	depth = simple_strtoul(buf, NULL, 0);
+	if(depth > NCR_700_MAX_TAGS)
+		return -EINVAL;
+	scsi_adjust_queue_depth(SDp, MSG_ORDERED_TAG, depth);
+
+	return count;
+}
+
+static ssize_t
+NCR_700_show_active_tags(struct device *dev, char *buf)
+{
+	struct scsi_device *SDp = to_scsi_device(dev);
+
+	return snprintf(buf, 20, "%d\n", NCR_700_get_depth(SDp));
+}
+
+static struct device_attribute NCR_700_queue_depth_attr = {
+	.attr = {
+		.name = 	"queue_depth",
+		.mode =		S_IWUSR,
+	},
+	.store = NCR_700_store_queue_depth,
+};
+
+static struct device_attribute NCR_700_active_tags_attr = {
+	.attr = {
+		.name =		"active_tags",
+		.mode =		S_IRUGO,
+	},
+	.show = NCR_700_show_active_tags,
+};
+
+STATIC int __init NCR_700_init(void)
+{
+	scsi_sysfs_modify_sdev_attribute(&NCR_700_dev_attrs,
+					 &NCR_700_queue_depth_attr);
+	scsi_sysfs_modify_sdev_attribute(&NCR_700_dev_attrs,
+					 &NCR_700_active_tags_attr);
+	return 0;
+}
+
 EXPORT_SYMBOL(NCR_700_detect);
 EXPORT_SYMBOL(NCR_700_release);
 EXPORT_SYMBOL(NCR_700_intr);
+
+module_init(NCR_700_init);