1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright 2008 ioogle, Inc. All rights reserved.
5 * Libata transport class.
7 * The ATA transport class contains common code to deal with ATA HBAs,
8 * an approximated representation of ATA topologies in the driver model,
9 * and various sysfs attributes to expose these topologies and management
10 * interfaces to user-space.
12 * There are 3 objects defined in this class:
16 * Each port has a link object. Each link can have up to two devices for PATA
17 * and generally one for SATA.
18 * If there is SATA port multiplier [PMP], 15 additional ata_link object are
21 * These objects are created when the ata host is initialized and when a PMP is
22 * found. They are removed only when the HBA is removed, cleaned before the
27 #include <linux/kernel.h>
28 #include <linux/blkdev.h>
29 #include <linux/spinlock.h>
30 #include <linux/slab.h>
31 #include <scsi/scsi_transport.h>
32 #include <linux/libata.h>
33 #include <linux/hdreg.h>
34 #include <linux/uaccess.h>
35 #include <linux/pm_runtime.h>
38 #include "libata-transport.h"
40 #define ATA_PORT_ATTRS 3
41 #define ATA_LINK_ATTRS 3
42 #define ATA_DEV_ATTRS 9
44 struct scsi_transport_template;
45 struct scsi_transport_template *ata_scsi_transport_template;
48 struct scsi_transport_template t;
50 struct device_attribute private_port_attrs[ATA_PORT_ATTRS];
51 struct device_attribute private_link_attrs[ATA_LINK_ATTRS];
52 struct device_attribute private_dev_attrs[ATA_DEV_ATTRS];
54 struct transport_container link_attr_cont;
55 struct transport_container dev_attr_cont;
58 * The array of null terminated pointers to attributes
59 * needed by scsi_sysfs.c
61 struct device_attribute *link_attrs[ATA_LINK_ATTRS + 1];
62 struct device_attribute *port_attrs[ATA_PORT_ATTRS + 1];
63 struct device_attribute *dev_attrs[ATA_DEV_ATTRS + 1];
65 #define to_ata_internal(tmpl) container_of(tmpl, struct ata_internal, t)
68 #define tdev_to_device(d) \
69 container_of((d), struct ata_device, tdev)
70 #define transport_class_to_dev(dev) \
71 tdev_to_device((dev)->parent)
73 #define tdev_to_link(d) \
74 container_of((d), struct ata_link, tdev)
75 #define transport_class_to_link(dev) \
76 tdev_to_link((dev)->parent)
78 #define tdev_to_port(d) \
79 container_of((d), struct ata_port, tdev)
80 #define transport_class_to_port(dev) \
81 tdev_to_port((dev)->parent)
84 /* Device objects are always created whit link objects */
85 static int ata_tdev_add(struct ata_device *dev);
86 static void ata_tdev_delete(struct ata_device *dev);
90 * Hack to allow attributes of the same name in different objects.
92 #define ATA_DEVICE_ATTR(_prefix,_name,_mode,_show,_store) \
93 struct device_attribute device_attr_##_prefix##_##_name = \
94 __ATTR(_name,_mode,_show,_store)
96 #define ata_bitfield_name_match(title, table) \
98 get_ata_##title##_names(u32 table_key, char *buf) \
104 for (i = 0; i < ARRAY_SIZE(table); i++) { \
105 if (table[i].value & table_key) { \
106 len += sprintf(buf + len, "%s%s", \
107 prefix, table[i].name); \
111 len += sprintf(buf + len, "\n"); \
115 #define ata_bitfield_name_search(title, table) \
117 get_ata_##title##_names(u32 table_key, char *buf) \
122 for (i = 0; i < ARRAY_SIZE(table); i++) { \
123 if (table[i].value == table_key) { \
124 len += sprintf(buf + len, "%s", \
129 len += sprintf(buf + len, "\n"); \
136 } ata_class_names[] = {
137 { ATA_DEV_UNKNOWN, "unknown" },
138 { ATA_DEV_ATA, "ata" },
139 { ATA_DEV_ATA_UNSUP, "ata" },
140 { ATA_DEV_ATAPI, "atapi" },
141 { ATA_DEV_ATAPI_UNSUP, "atapi" },
142 { ATA_DEV_PMP, "pmp" },
143 { ATA_DEV_PMP_UNSUP, "pmp" },
144 { ATA_DEV_SEMB, "semb" },
145 { ATA_DEV_SEMB_UNSUP, "semb" },
146 { ATA_DEV_ZAC, "zac" },
147 { ATA_DEV_NONE, "none" }
149 ata_bitfield_name_search(class, ata_class_names)
155 } ata_err_names[] = {
156 { AC_ERR_DEV, "DeviceError" },
157 { AC_ERR_HSM, "HostStateMachineError" },
158 { AC_ERR_TIMEOUT, "Timeout" },
159 { AC_ERR_MEDIA, "MediaError" },
160 { AC_ERR_ATA_BUS, "BusError" },
161 { AC_ERR_HOST_BUS, "HostBusError" },
162 { AC_ERR_SYSTEM, "SystemError" },
163 { AC_ERR_INVALID, "InvalidArg" },
164 { AC_ERR_OTHER, "Unknown" },
165 { AC_ERR_NODEV_HINT, "NoDeviceHint" },
166 { AC_ERR_NCQ, "NCQError" }
168 ata_bitfield_name_match(err, ata_err_names)
173 } ata_xfer_names[] = {
174 { XFER_UDMA_7, "XFER_UDMA_7" },
175 { XFER_UDMA_6, "XFER_UDMA_6" },
176 { XFER_UDMA_5, "XFER_UDMA_5" },
177 { XFER_UDMA_4, "XFER_UDMA_4" },
178 { XFER_UDMA_3, "XFER_UDMA_3" },
179 { XFER_UDMA_2, "XFER_UDMA_2" },
180 { XFER_UDMA_1, "XFER_UDMA_1" },
181 { XFER_UDMA_0, "XFER_UDMA_0" },
182 { XFER_MW_DMA_4, "XFER_MW_DMA_4" },
183 { XFER_MW_DMA_3, "XFER_MW_DMA_3" },
184 { XFER_MW_DMA_2, "XFER_MW_DMA_2" },
185 { XFER_MW_DMA_1, "XFER_MW_DMA_1" },
186 { XFER_MW_DMA_0, "XFER_MW_DMA_0" },
187 { XFER_SW_DMA_2, "XFER_SW_DMA_2" },
188 { XFER_SW_DMA_1, "XFER_SW_DMA_1" },
189 { XFER_SW_DMA_0, "XFER_SW_DMA_0" },
190 { XFER_PIO_6, "XFER_PIO_6" },
191 { XFER_PIO_5, "XFER_PIO_5" },
192 { XFER_PIO_4, "XFER_PIO_4" },
193 { XFER_PIO_3, "XFER_PIO_3" },
194 { XFER_PIO_2, "XFER_PIO_2" },
195 { XFER_PIO_1, "XFER_PIO_1" },
196 { XFER_PIO_0, "XFER_PIO_0" },
197 { XFER_PIO_SLOW, "XFER_PIO_SLOW" }
199 ata_bitfield_name_search(xfer, ata_xfer_names)
202 * ATA Port attributes
204 #define ata_port_show_simple(field, name, format_string, cast) \
206 show_ata_port_##name(struct device *dev, \
207 struct device_attribute *attr, char *buf) \
209 struct ata_port *ap = transport_class_to_port(dev); \
211 return scnprintf(buf, 20, format_string, cast ap->field); \
214 #define ata_port_simple_attr(field, name, format_string, type) \
215 ata_port_show_simple(field, name, format_string, (type)) \
216 static DEVICE_ATTR(name, S_IRUGO, show_ata_port_##name, NULL)
218 ata_port_simple_attr(nr_pmp_links, nr_pmp_links, "%d\n", int);
219 ata_port_simple_attr(stats.idle_irq, idle_irq, "%ld\n", unsigned long);
220 ata_port_simple_attr(local_port_no, port_no, "%u\n", unsigned int);
222 static DECLARE_TRANSPORT_CLASS(ata_port_class,
223 "ata_port", NULL, NULL, NULL);
225 static void ata_tport_release(struct device *dev)
227 struct ata_port *ap = tdev_to_port(dev);
228 ata_host_put(ap->host);
232 * ata_is_port -- check if a struct device represents a ATA port
233 * @dev: device to check
236 * %1 if the device represents a ATA Port, %0 else
238 static int ata_is_port(const struct device *dev)
240 return dev->release == ata_tport_release;
243 static int ata_tport_match(struct attribute_container *cont,
246 if (!ata_is_port(dev))
248 return &ata_scsi_transport_template->host_attrs.ac == cont;
252 * ata_tport_delete -- remove ATA PORT
253 * @ap: ATA PORT to remove
255 * Removes the specified ATA PORT. Remove the associated link as well.
257 void ata_tport_delete(struct ata_port *ap)
259 struct device *dev = &ap->tdev;
261 ata_tlink_delete(&ap->link);
263 transport_remove_device(dev);
265 transport_destroy_device(dev);
269 /** ata_tport_add - initialize a transport ATA port structure
271 * @parent: parent device
272 * @ap: existing ata_port structure
274 * Initialize a ATA port structure for sysfs. It will be added to the device
275 * tree below the device specified by @parent which could be a PCI device.
277 * Returns %0 on success
279 int ata_tport_add(struct device *parent,
283 struct device *dev = &ap->tdev;
285 device_initialize(dev);
286 dev->type = &ata_port_type;
288 dev->parent = parent;
289 ata_host_get(ap->host);
290 dev->release = ata_tport_release;
291 dev_set_name(dev, "ata%d", ap->print_id);
292 transport_setup_device(dev);
293 ata_acpi_bind_port(ap);
294 error = device_add(dev);
299 device_enable_async_suspend(dev);
300 pm_runtime_set_active(dev);
301 pm_runtime_enable(dev);
302 pm_runtime_forbid(dev);
304 transport_add_device(dev);
305 transport_configure_device(dev);
307 error = ata_tlink_add(&ap->link);
314 transport_remove_device(dev);
318 transport_destroy_device(dev);
320 ata_host_put(ap->host);
325 * ata_port_classify - determine device type based on ATA-spec signature
326 * @ap: ATA port device on which the classification should be run
327 * @tf: ATA taskfile register set for device to be identified
329 * A wrapper around ata_dev_classify() to provide additional logging
332 * Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP,
333 * %ATA_DEV_ZAC, or %ATA_DEV_UNKNOWN the event of failure.
335 unsigned int ata_port_classify(struct ata_port *ap,
336 const struct ata_taskfile *tf)
339 unsigned int class = ata_dev_classify(tf);
341 /* Start with index '1' to skip the 'unknown' entry */
342 for (i = 1; i < ARRAY_SIZE(ata_class_names); i++) {
343 if (ata_class_names[i].value == class) {
344 ata_port_dbg(ap, "found %s device by sig\n",
345 ata_class_names[i].name);
350 ata_port_info(ap, "found unknown device (class %u)\n", class);
353 EXPORT_SYMBOL_GPL(ata_port_classify);
356 * ATA link attributes
358 static int noop(int x) { return x; }
360 #define ata_link_show_linkspeed(field, format) \
362 show_ata_link_##field(struct device *dev, \
363 struct device_attribute *attr, char *buf) \
365 struct ata_link *link = transport_class_to_link(dev); \
367 return sprintf(buf, "%s\n", sata_spd_string(format(link->field))); \
370 #define ata_link_linkspeed_attr(field, format) \
371 ata_link_show_linkspeed(field, format) \
372 static DEVICE_ATTR(field, S_IRUGO, show_ata_link_##field, NULL)
374 ata_link_linkspeed_attr(hw_sata_spd_limit, fls);
375 ata_link_linkspeed_attr(sata_spd_limit, fls);
376 ata_link_linkspeed_attr(sata_spd, noop);
379 static DECLARE_TRANSPORT_CLASS(ata_link_class,
380 "ata_link", NULL, NULL, NULL);
382 static void ata_tlink_release(struct device *dev)
387 * ata_is_link -- check if a struct device represents a ATA link
388 * @dev: device to check
391 * %1 if the device represents a ATA link, %0 else
393 static int ata_is_link(const struct device *dev)
395 return dev->release == ata_tlink_release;
398 static int ata_tlink_match(struct attribute_container *cont,
401 struct ata_internal* i = to_ata_internal(ata_scsi_transport_template);
402 if (!ata_is_link(dev))
404 return &i->link_attr_cont.ac == cont;
408 * ata_tlink_delete -- remove ATA LINK
409 * @link: ATA LINK to remove
411 * Removes the specified ATA LINK. remove associated ATA device(s) as well.
413 void ata_tlink_delete(struct ata_link *link)
415 struct device *dev = &link->tdev;
416 struct ata_device *ata_dev;
418 ata_for_each_dev(ata_dev, link, ALL) {
419 ata_tdev_delete(ata_dev);
422 transport_remove_device(dev);
424 transport_destroy_device(dev);
429 * ata_tlink_add -- initialize a transport ATA link structure
430 * @link: allocated ata_link structure.
432 * Initialize an ATA LINK structure for sysfs. It will be added in the
433 * device tree below the ATA PORT it belongs to.
435 * Returns %0 on success
437 int ata_tlink_add(struct ata_link *link)
439 struct device *dev = &link->tdev;
440 struct ata_port *ap = link->ap;
441 struct ata_device *ata_dev;
444 device_initialize(dev);
445 dev->parent = &ap->tdev;
446 dev->release = ata_tlink_release;
447 if (ata_is_host_link(link))
448 dev_set_name(dev, "link%d", ap->print_id);
450 dev_set_name(dev, "link%d.%d", ap->print_id, link->pmp);
452 transport_setup_device(dev);
454 error = device_add(dev);
459 transport_add_device(dev);
460 transport_configure_device(dev);
462 ata_for_each_dev(ata_dev, link, ALL) {
463 error = ata_tdev_add(ata_dev);
470 while (--ata_dev >= link->device) {
471 ata_tdev_delete(ata_dev);
473 transport_remove_device(dev);
476 transport_destroy_device(dev);
482 * ATA device attributes
485 #define ata_dev_show_class(title, field) \
487 show_ata_dev_##field(struct device *dev, \
488 struct device_attribute *attr, char *buf) \
490 struct ata_device *ata_dev = transport_class_to_dev(dev); \
492 return get_ata_##title##_names(ata_dev->field, buf); \
495 #define ata_dev_attr(title, field) \
496 ata_dev_show_class(title, field) \
497 static DEVICE_ATTR(field, S_IRUGO, show_ata_dev_##field, NULL)
499 ata_dev_attr(class, class);
500 ata_dev_attr(xfer, pio_mode);
501 ata_dev_attr(xfer, dma_mode);
502 ata_dev_attr(xfer, xfer_mode);
505 #define ata_dev_show_simple(field, format_string, cast) \
507 show_ata_dev_##field(struct device *dev, \
508 struct device_attribute *attr, char *buf) \
510 struct ata_device *ata_dev = transport_class_to_dev(dev); \
512 return scnprintf(buf, 20, format_string, cast ata_dev->field); \
515 #define ata_dev_simple_attr(field, format_string, type) \
516 ata_dev_show_simple(field, format_string, (type)) \
517 static DEVICE_ATTR(field, S_IRUGO, \
518 show_ata_dev_##field, NULL)
520 ata_dev_simple_attr(spdn_cnt, "%d\n", int);
522 struct ata_show_ering_arg {
527 static int ata_show_ering(struct ata_ering_entry *ent, void *void_arg)
529 struct ata_show_ering_arg* arg = void_arg;
533 seconds = div_u64_rem(ent->timestamp, HZ, &rem);
534 arg->written += sprintf(arg->buf + arg->written,
535 "[%5llu.%09lu]", seconds,
536 rem * NSEC_PER_SEC / HZ);
537 arg->written += get_ata_err_names(ent->err_mask,
538 arg->buf + arg->written);
543 show_ata_dev_ering(struct device *dev,
544 struct device_attribute *attr, char *buf)
546 struct ata_device *ata_dev = transport_class_to_dev(dev);
547 struct ata_show_ering_arg arg = { buf, 0 };
549 ata_ering_map(&ata_dev->ering, ata_show_ering, &arg);
554 static DEVICE_ATTR(ering, S_IRUGO, show_ata_dev_ering, NULL);
557 show_ata_dev_id(struct device *dev,
558 struct device_attribute *attr, char *buf)
560 struct ata_device *ata_dev = transport_class_to_dev(dev);
561 int written = 0, i = 0;
563 if (ata_dev->class == ATA_DEV_PMP)
565 for(i=0;i<ATA_ID_WORDS;i++) {
566 written += scnprintf(buf+written, 20, "%04x%c",
568 ((i+1) & 7) ? ' ' : '\n');
573 static DEVICE_ATTR(id, S_IRUGO, show_ata_dev_id, NULL);
576 show_ata_dev_gscr(struct device *dev,
577 struct device_attribute *attr, char *buf)
579 struct ata_device *ata_dev = transport_class_to_dev(dev);
580 int written = 0, i = 0;
582 if (ata_dev->class != ATA_DEV_PMP)
584 for(i=0;i<SATA_PMP_GSCR_DWORDS;i++) {
585 written += scnprintf(buf+written, 20, "%08x%c",
587 ((i+1) & 3) ? ' ' : '\n');
589 if (SATA_PMP_GSCR_DWORDS & 3)
590 buf[written-1] = '\n';
594 static DEVICE_ATTR(gscr, S_IRUGO, show_ata_dev_gscr, NULL);
597 show_ata_dev_trim(struct device *dev,
598 struct device_attribute *attr, char *buf)
600 struct ata_device *ata_dev = transport_class_to_dev(dev);
603 if (!ata_id_has_trim(ata_dev->id))
604 mode = "unsupported";
605 else if (ata_dev->horkage & ATA_HORKAGE_NOTRIM)
606 mode = "forced_unsupported";
607 else if (ata_dev->horkage & ATA_HORKAGE_NO_NCQ_TRIM)
608 mode = "forced_unqueued";
609 else if (ata_fpdma_dsm_supported(ata_dev))
614 return scnprintf(buf, 20, "%s\n", mode);
617 static DEVICE_ATTR(trim, S_IRUGO, show_ata_dev_trim, NULL);
619 static DECLARE_TRANSPORT_CLASS(ata_dev_class,
620 "ata_device", NULL, NULL, NULL);
622 static void ata_tdev_release(struct device *dev)
627 * ata_is_ata_dev -- check if a struct device represents a ATA device
628 * @dev: device to check
631 * %1 if the device represents a ATA device, %0 else
633 static int ata_is_ata_dev(const struct device *dev)
635 return dev->release == ata_tdev_release;
638 static int ata_tdev_match(struct attribute_container *cont,
641 struct ata_internal* i = to_ata_internal(ata_scsi_transport_template);
642 if (!ata_is_ata_dev(dev))
644 return &i->dev_attr_cont.ac == cont;
648 * ata_tdev_free -- free a ATA LINK
649 * @dev: ATA PHY to free
651 * Frees the specified ATA PHY.
654 * This function must only be called on a PHY that has not
655 * successfully been added using ata_tdev_add().
657 static void ata_tdev_free(struct ata_device *dev)
659 transport_destroy_device(&dev->tdev);
660 put_device(&dev->tdev);
664 * ata_tdev_delete -- remove ATA device
665 * @ata_dev: ATA device to remove
667 * Removes the specified ATA device.
669 static void ata_tdev_delete(struct ata_device *ata_dev)
671 struct device *dev = &ata_dev->tdev;
673 transport_remove_device(dev);
675 ata_tdev_free(ata_dev);
680 * ata_tdev_add -- initialize a transport ATA device structure.
681 * @ata_dev: ata_dev structure.
683 * Initialize an ATA device structure for sysfs. It will be added in the
684 * device tree below the ATA LINK device it belongs to.
686 * Returns %0 on success
688 static int ata_tdev_add(struct ata_device *ata_dev)
690 struct device *dev = &ata_dev->tdev;
691 struct ata_link *link = ata_dev->link;
692 struct ata_port *ap = link->ap;
695 device_initialize(dev);
696 dev->parent = &link->tdev;
697 dev->release = ata_tdev_release;
698 if (ata_is_host_link(link))
699 dev_set_name(dev, "dev%d.%d", ap->print_id,ata_dev->devno);
701 dev_set_name(dev, "dev%d.%d.0", ap->print_id, link->pmp);
703 transport_setup_device(dev);
704 ata_acpi_bind_dev(ata_dev);
705 error = device_add(dev);
707 ata_tdev_free(ata_dev);
711 transport_add_device(dev);
712 transport_configure_device(dev);
718 * Setup / Teardown code
721 #define SETUP_TEMPLATE(attrb, field, perm, test) \
722 i->private_##attrb[count] = dev_attr_##field; \
723 i->private_##attrb[count].attr.mode = perm; \
724 i->attrb[count] = &i->private_##attrb[count]; \
728 #define SETUP_LINK_ATTRIBUTE(field) \
729 SETUP_TEMPLATE(link_attrs, field, S_IRUGO, 1)
731 #define SETUP_PORT_ATTRIBUTE(field) \
732 SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1)
734 #define SETUP_DEV_ATTRIBUTE(field) \
735 SETUP_TEMPLATE(dev_attrs, field, S_IRUGO, 1)
738 * ata_attach_transport -- instantiate ATA transport template
740 struct scsi_transport_template *ata_attach_transport(void)
742 struct ata_internal *i;
745 i = kzalloc(sizeof(struct ata_internal), GFP_KERNEL);
749 i->t.eh_strategy_handler = ata_scsi_error;
750 i->t.user_scan = ata_scsi_user_scan;
752 i->t.host_attrs.ac.attrs = &i->port_attrs[0];
753 i->t.host_attrs.ac.class = &ata_port_class.class;
754 i->t.host_attrs.ac.match = ata_tport_match;
755 transport_container_register(&i->t.host_attrs);
757 i->link_attr_cont.ac.class = &ata_link_class.class;
758 i->link_attr_cont.ac.attrs = &i->link_attrs[0];
759 i->link_attr_cont.ac.match = ata_tlink_match;
760 transport_container_register(&i->link_attr_cont);
762 i->dev_attr_cont.ac.class = &ata_dev_class.class;
763 i->dev_attr_cont.ac.attrs = &i->dev_attrs[0];
764 i->dev_attr_cont.ac.match = ata_tdev_match;
765 transport_container_register(&i->dev_attr_cont);
768 SETUP_PORT_ATTRIBUTE(nr_pmp_links);
769 SETUP_PORT_ATTRIBUTE(idle_irq);
770 SETUP_PORT_ATTRIBUTE(port_no);
771 BUG_ON(count > ATA_PORT_ATTRS);
772 i->port_attrs[count] = NULL;
775 SETUP_LINK_ATTRIBUTE(hw_sata_spd_limit);
776 SETUP_LINK_ATTRIBUTE(sata_spd_limit);
777 SETUP_LINK_ATTRIBUTE(sata_spd);
778 BUG_ON(count > ATA_LINK_ATTRS);
779 i->link_attrs[count] = NULL;
782 SETUP_DEV_ATTRIBUTE(class);
783 SETUP_DEV_ATTRIBUTE(pio_mode);
784 SETUP_DEV_ATTRIBUTE(dma_mode);
785 SETUP_DEV_ATTRIBUTE(xfer_mode);
786 SETUP_DEV_ATTRIBUTE(spdn_cnt);
787 SETUP_DEV_ATTRIBUTE(ering);
788 SETUP_DEV_ATTRIBUTE(id);
789 SETUP_DEV_ATTRIBUTE(gscr);
790 SETUP_DEV_ATTRIBUTE(trim);
791 BUG_ON(count > ATA_DEV_ATTRS);
792 i->dev_attrs[count] = NULL;
798 * ata_release_transport -- release ATA transport template instance
799 * @t: transport template instance
801 void ata_release_transport(struct scsi_transport_template *t)
803 struct ata_internal *i = to_ata_internal(t);
805 transport_container_unregister(&i->t.host_attrs);
806 transport_container_unregister(&i->link_attr_cont);
807 transport_container_unregister(&i->dev_attr_cont);
812 __init int libata_transport_init(void)
816 error = transport_class_register(&ata_link_class);
818 goto out_unregister_transport;
819 error = transport_class_register(&ata_port_class);
821 goto out_unregister_link;
822 error = transport_class_register(&ata_dev_class);
824 goto out_unregister_port;
828 transport_class_unregister(&ata_port_class);
830 transport_class_unregister(&ata_link_class);
831 out_unregister_transport:
836 void __exit libata_transport_exit(void)
838 transport_class_unregister(&ata_link_class);
839 transport_class_unregister(&ata_port_class);
840 transport_class_unregister(&ata_dev_class);