2 * ACPI PCI Hot Plug IBM Extension
4 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
5 * Copyright (C) 2004 IBM Corp.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
17 * NON INFRINGEMENT. See the GNU General Public License for more
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * Send feedback to <vernux@us.ibm.com>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <acpi/acpi_bus.h>
33 #include <linux/sysfs.h>
34 #include <linux/kobject.h>
35 #include <asm/uaccess.h>
36 #include <linux/moduleparam.h>
37 #include <linux/pci.h>
42 #define DRIVER_VERSION "1.0.1"
43 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
44 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension"
48 MODULE_AUTHOR(DRIVER_AUTHOR);
49 MODULE_DESCRIPTION(DRIVER_DESC);
50 MODULE_LICENSE("GPL");
51 MODULE_VERSION(DRIVER_VERSION);
52 module_param(debug, bool, 0644);
53 MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
54 #define MY_NAME "acpiphp_ibm"
57 #define dbg(format, arg...) \
60 printk(KERN_DEBUG "%s: " format, \
64 #define FOUND_APCI 0x61504349
65 /* these are the names for the IBM ACPI pseudo-device */
66 #define IBM_HARDWARE_ID1 "IBM37D0"
67 #define IBM_HARDWARE_ID2 "IBM37D4"
69 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun)
71 /* union apci_descriptor - allows access to the
72 * various device descriptors that are embedded in the
75 union apci_descriptor {
99 /* struct notification - keeps info about the device
100 * that cause the ACPI notification event
102 struct notification {
103 struct acpi_device *device;
107 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
108 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
109 static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
110 static int ibm_get_table_from_acpi(char **bufp);
111 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
112 struct bin_attribute *bin_attr,
113 char *buffer, loff_t pos, size_t size);
114 static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
115 u32 lvl, void *context, void **rv);
116 static int __init ibm_acpiphp_init(void);
117 static void __exit ibm_acpiphp_exit(void);
119 static acpi_handle ibm_acpi_handle;
120 static struct notification ibm_note;
121 static struct bin_attribute ibm_apci_table_attr = {
123 .name = "apci_table",
126 .read = ibm_read_apci_table,
129 static struct acpiphp_attention_info ibm_attention_info =
131 .set_attn = ibm_set_attention_status,
132 .get_attn = ibm_get_attention_status,
133 .owner = THIS_MODULE,
137 * ibm_slot_from_id - workaround for bad ibm hardware
138 * @id: the slot number that linux refers to the slot by
140 * Description: This method returns the aCPI slot descriptor
141 * corresponding to the Linux slot number. This descriptor
142 * has info about the aPCI slot id and attention status.
143 * This descriptor must be freed using kfree when done.
145 static union apci_descriptor *ibm_slot_from_id(int id)
148 union apci_descriptor *ret = NULL, *des;
151 size = ibm_get_table_from_acpi(&table);
152 des = (union apci_descriptor *)table;
153 if (memcmp(des->header.sig, "aPCI", 4) != 0)
156 des = (union apci_descriptor *)&table[ind += des->header.len];
157 while (ind < size && (des->generic.type != 0x82 ||
158 des->slot.slot_num != id)) {
159 des = (union apci_descriptor *)&table[ind += des->generic.len];
162 if (ind < size && des->slot.slot_num == id)
167 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
168 memcpy(ret, des, sizeof(union apci_descriptor));
175 * ibm_set_attention_status - callback method to set the attention LED
176 * @slot: the hotplug_slot to work with
177 * @status: what to set the LED to (0 or 1)
179 * Description: This method is registered with the acpiphp module as a
180 * callback to do the device specific task of setting the LED status.
182 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
184 union acpi_object args[2];
185 struct acpi_object_list params = { .pointer = args, .count = 2 };
187 unsigned long long rc;
188 union apci_descriptor *ibm_slot;
190 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
192 dbg("%s: set slot %d (%d) attention status to %d\n", __func__,
193 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
196 args[0].type = ACPI_TYPE_INTEGER;
197 args[0].integer.value = ibm_slot->slot.slot_id;
198 args[1].type = ACPI_TYPE_INTEGER;
199 args[1].integer.value = (status) ? 1 : 0;
203 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc);
204 if (ACPI_FAILURE(stat)) {
205 err("APLS evaluation failed: 0x%08x\n", stat);
208 err("APLS method failed: 0x%08llx\n", rc);
215 * ibm_get_attention_status - callback method to get attention LED status
216 * @slot: the hotplug_slot to work with
217 * @status: returns what the LED is set to (0 or 1)
219 * Description: This method is registered with the acpiphp module as a
220 * callback to do the device specific task of getting the LED status.
222 * Because there is no direct method of getting the LED status directly
223 * from an ACPI call, we read the aPCI table and parse out our
224 * slot descriptor to read the status from that.
226 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
228 union apci_descriptor *ibm_slot;
230 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
232 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
237 dbg("%s: get slot %d (%d) attention status is %d\n", __func__,
238 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
246 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
247 * @handle: an ACPI handle to the device that caused the event
248 * @event: the event info (device specific)
249 * @context: passed context (our notification struct)
251 * Description: This method is registered as a callback with the ACPI
252 * subsystem it is called when this device has an event to notify the OS of.
254 * The events actually come from the device as two events that get
255 * synthesized into one event with data by this function. The event
256 * ID comes first and then the slot number that caused it. We report
257 * this as one event to the OS.
259 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
260 * only re-enable the interrupt that causes this event AFTER this method
261 * has returned, thereby enforcing serial access for the notification struct.
263 static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
265 u8 detail = event & 0x0f;
266 u8 subevent = event & 0xf0;
267 struct notification *note = context;
269 dbg("%s: Received notification %02x\n", __func__, event);
271 if (subevent == 0x80) {
272 dbg("%s: generationg bus event\n", __func__);
273 acpi_bus_generate_netlink_event(note->device->pnp.device_class,
274 dev_name(¬e->device->dev),
275 note->event, detail);
281 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
282 * @bufp: address to pointer to allocate for the table
284 * Description: This method reads the APLS buffer in from ACPI and
285 * stores the "stripped" table into a single buffer
286 * it allocates and passes the address back in bufp.
288 * If NULL is passed in as buffer, this method only calculates
289 * the size of the table and returns that without filling
292 * Returns < 0 on error or the size of the table on success.
294 static int ibm_get_table_from_acpi(char **bufp)
296 union acpi_object *package;
297 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
302 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
303 if (ACPI_FAILURE(status)) {
304 err("%s: APCI evaluation failed\n", __func__);
308 package = (union acpi_object *) buffer.pointer;
310 (package->type != ACPI_TYPE_PACKAGE) ||
311 !(package->package.elements)) {
312 err("%s: Invalid APCI object\n", __func__);
313 goto read_table_done;
316 for(size = 0, i = 0; i < package->package.count; i++) {
317 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
318 err("%s: Invalid APCI element %d\n", __func__, i);
319 goto read_table_done;
321 size += package->package.elements[i].buffer.length;
325 goto read_table_done;
327 lbuf = kzalloc(size, GFP_KERNEL);
328 dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
329 __func__, package->package.count, size, lbuf);
335 goto read_table_done;
339 for (i=0; i<package->package.count; i++) {
341 package->package.elements[i].buffer.pointer,
342 package->package.elements[i].buffer.length);
343 size += package->package.elements[i].buffer.length;
347 kfree(buffer.pointer);
352 * ibm_read_apci_table - callback for the sysfs apci_table file
353 * @filp: the open sysfs file
354 * @kobj: the kobject this binary attribute is a part of
355 * @bin_attr: struct bin_attribute for this file
356 * @buffer: the kernel space buffer to fill
357 * @pos: the offset into the file
358 * @size: the number of bytes requested
360 * Description: Gets registered with sysfs as the reader callback
361 * to be executed when /sys/bus/pci/slots/apci_table gets read.
363 * Since we don't get notified on open and close for this file,
364 * things get really tricky here...
365 * our solution is to only allow reading the table in all at once.
367 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
368 struct bin_attribute *bin_attr,
369 char *buffer, loff_t pos, size_t size)
371 int bytes_read = -EINVAL;
374 dbg("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
377 bytes_read = ibm_get_table_from_acpi(&table);
378 if (bytes_read > 0 && bytes_read <= size)
379 memcpy(buffer, table, bytes_read);
386 * ibm_find_acpi_device - callback to find our ACPI device
387 * @handle: the ACPI handle of the device we are inspecting
388 * @lvl: depth into the namespace tree
389 * @context: a pointer to our handle to fill when we find the device
390 * @rv: a return value to fill if desired
392 * Description: Used as a callback when calling acpi_walk_namespace
393 * to find our device. When this method returns non-zero
394 * acpi_walk_namespace quits its search and returns our value.
396 static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
397 u32 lvl, void *context, void **rv)
399 acpi_handle *phandle = (acpi_handle *)context;
401 struct acpi_device_info *info;
404 status = acpi_get_object_info(handle, &info);
405 if (ACPI_FAILURE(status)) {
406 err("%s: Failed to get device information status=0x%x\n",
411 if (info->current_status && (info->valid & ACPI_VALID_HID) &&
412 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
413 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
414 dbg("found hardware: %s, handle: %p\n",
415 info->hardware_id.string, handle);
417 /* returning non-zero causes the search to stop
418 * and returns this value to the caller of
419 * acpi_walk_namespace, but it also causes some warnings
420 * in the acpi debug code to print...
428 static int __init ibm_acpiphp_init(void)
432 struct acpi_device *device;
433 struct kobject *sysdir = &pci_slots_kset->kobj;
435 dbg("%s\n", __func__);
437 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
438 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
439 &ibm_acpi_handle, NULL) != FOUND_APCI) {
440 err("%s: acpi_walk_namespace failed\n", __func__);
444 dbg("%s: found IBM aPCI device\n", __func__);
445 if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
446 err("%s: acpi_bus_get_device failed\n", __func__);
450 if (acpiphp_register_attention(&ibm_attention_info)) {
455 ibm_note.device = device;
456 status = acpi_install_notify_handler(ibm_acpi_handle,
457 ACPI_DEVICE_NOTIFY, ibm_handle_events,
459 if (ACPI_FAILURE(status)) {
460 err("%s: Failed to register notification handler\n",
466 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
467 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
472 acpiphp_unregister_attention(&ibm_attention_info);
477 static void __exit ibm_acpiphp_exit(void)
480 struct kobject *sysdir = &pci_slots_kset->kobj;
482 dbg("%s\n", __func__);
484 if (acpiphp_unregister_attention(&ibm_attention_info))
485 err("%s: attention info deregistration failed", __func__);
487 status = acpi_remove_notify_handler(
491 if (ACPI_FAILURE(status))
492 err("%s: Notification handler removal failed\n", __func__);
493 /* remove the /sys entries */
494 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
497 module_init(ibm_acpiphp_init);
498 module_exit(ibm_acpiphp_exit);