xref: /openbmc/linux/drivers/pci/hotplug/pciehp_hpc.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * PCI Express PCI Hot Plug Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2003-2004 Intel Corporation
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com>
27  *
28  */
29 
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/types.h>
33 #include <linux/signal.h>
34 #include <linux/jiffies.h>
35 #include <linux/timer.h>
36 #include <linux/pci.h>
37 #include <linux/interrupt.h>
38 #include <linux/time.h>
39 
40 #include "../pci.h"
41 #include "pciehp.h"
42 
43 static atomic_t pciehp_num_controllers = ATOMIC_INIT(0);
44 
45 struct ctrl_reg {
46 	u8 cap_id;
47 	u8 nxt_ptr;
48 	u16 cap_reg;
49 	u32 dev_cap;
50 	u16 dev_ctrl;
51 	u16 dev_status;
52 	u32 lnk_cap;
53 	u16 lnk_ctrl;
54 	u16 lnk_status;
55 	u32 slot_cap;
56 	u16 slot_ctrl;
57 	u16 slot_status;
58 	u16 root_ctrl;
59 	u16 rsvp;
60 	u32 root_status;
61 } __attribute__ ((packed));
62 
63 /* offsets to the controller registers based on the above structure layout */
64 enum ctrl_offsets {
65 	PCIECAPID	=	offsetof(struct ctrl_reg, cap_id),
66 	NXTCAPPTR	=	offsetof(struct ctrl_reg, nxt_ptr),
67 	CAPREG		=	offsetof(struct ctrl_reg, cap_reg),
68 	DEVCAP		=	offsetof(struct ctrl_reg, dev_cap),
69 	DEVCTRL		=	offsetof(struct ctrl_reg, dev_ctrl),
70 	DEVSTATUS	=	offsetof(struct ctrl_reg, dev_status),
71 	LNKCAP		=	offsetof(struct ctrl_reg, lnk_cap),
72 	LNKCTRL		=	offsetof(struct ctrl_reg, lnk_ctrl),
73 	LNKSTATUS	=	offsetof(struct ctrl_reg, lnk_status),
74 	SLOTCAP		=	offsetof(struct ctrl_reg, slot_cap),
75 	SLOTCTRL	=	offsetof(struct ctrl_reg, slot_ctrl),
76 	SLOTSTATUS	=	offsetof(struct ctrl_reg, slot_status),
77 	ROOTCTRL	=	offsetof(struct ctrl_reg, root_ctrl),
78 	ROOTSTATUS	=	offsetof(struct ctrl_reg, root_status),
79 };
80 
81 static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
82 {
83 	struct pci_dev *dev = ctrl->pci_dev;
84 	return pci_read_config_word(dev, ctrl->cap_base + reg, value);
85 }
86 
87 static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
88 {
89 	struct pci_dev *dev = ctrl->pci_dev;
90 	return pci_read_config_dword(dev, ctrl->cap_base + reg, value);
91 }
92 
93 static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
94 {
95 	struct pci_dev *dev = ctrl->pci_dev;
96 	return pci_write_config_word(dev, ctrl->cap_base + reg, value);
97 }
98 
99 static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
100 {
101 	struct pci_dev *dev = ctrl->pci_dev;
102 	return pci_write_config_dword(dev, ctrl->cap_base + reg, value);
103 }
104 
105 /* Field definitions in PCI Express Capabilities Register */
106 #define CAP_VER			0x000F
107 #define DEV_PORT_TYPE		0x00F0
108 #define SLOT_IMPL		0x0100
109 #define MSG_NUM			0x3E00
110 
111 /* Device or Port Type */
112 #define NAT_ENDPT		0x00
113 #define LEG_ENDPT		0x01
114 #define ROOT_PORT		0x04
115 #define UP_STREAM		0x05
116 #define	DN_STREAM		0x06
117 #define PCIE_PCI_BRDG		0x07
118 #define PCI_PCIE_BRDG		0x10
119 
120 /* Field definitions in Device Capabilities Register */
121 #define DATTN_BUTTN_PRSN	0x1000
122 #define DATTN_LED_PRSN		0x2000
123 #define DPWR_LED_PRSN		0x4000
124 
125 /* Field definitions in Link Capabilities Register */
126 #define MAX_LNK_SPEED		0x000F
127 #define MAX_LNK_WIDTH		0x03F0
128 
129 /* Link Width Encoding */
130 #define LNK_X1		0x01
131 #define LNK_X2		0x02
132 #define LNK_X4		0x04
133 #define LNK_X8		0x08
134 #define LNK_X12		0x0C
135 #define LNK_X16		0x10
136 #define LNK_X32		0x20
137 
138 /*Field definitions of Link Status Register */
139 #define LNK_SPEED	0x000F
140 #define NEG_LINK_WD	0x03F0
141 #define LNK_TRN_ERR	0x0400
142 #define	LNK_TRN		0x0800
143 #define SLOT_CLK_CONF	0x1000
144 
145 /* Field definitions in Slot Capabilities Register */
146 #define ATTN_BUTTN_PRSN	0x00000001
147 #define	PWR_CTRL_PRSN	0x00000002
148 #define MRL_SENS_PRSN	0x00000004
149 #define ATTN_LED_PRSN	0x00000008
150 #define PWR_LED_PRSN	0x00000010
151 #define HP_SUPR_RM_SUP	0x00000020
152 #define HP_CAP		0x00000040
153 #define SLOT_PWR_VALUE	0x000003F8
154 #define SLOT_PWR_LIMIT	0x00000C00
155 #define PSN		0xFFF80000	/* PSN: Physical Slot Number */
156 
157 /* Field definitions in Slot Control Register */
158 #define ATTN_BUTTN_ENABLE		0x0001
159 #define PWR_FAULT_DETECT_ENABLE		0x0002
160 #define MRL_DETECT_ENABLE		0x0004
161 #define PRSN_DETECT_ENABLE		0x0008
162 #define CMD_CMPL_INTR_ENABLE		0x0010
163 #define HP_INTR_ENABLE			0x0020
164 #define ATTN_LED_CTRL			0x00C0
165 #define PWR_LED_CTRL			0x0300
166 #define PWR_CTRL			0x0400
167 #define EMI_CTRL			0x0800
168 
169 /* Attention indicator and Power indicator states */
170 #define LED_ON		0x01
171 #define LED_BLINK	0x10
172 #define LED_OFF		0x11
173 
174 /* Power Control Command */
175 #define POWER_ON	0
176 #define POWER_OFF	0x0400
177 
178 /* EMI Status defines */
179 #define EMI_DISENGAGED	0
180 #define EMI_ENGAGED	1
181 
182 /* Field definitions in Slot Status Register */
183 #define ATTN_BUTTN_PRESSED	0x0001
184 #define PWR_FAULT_DETECTED	0x0002
185 #define MRL_SENS_CHANGED	0x0004
186 #define PRSN_DETECT_CHANGED	0x0008
187 #define CMD_COMPLETED		0x0010
188 #define MRL_STATE		0x0020
189 #define PRSN_STATE		0x0040
190 #define EMI_STATE		0x0080
191 #define EMI_STATUS_BIT		7
192 
193 static irqreturn_t pcie_isr(int irq, void *dev_id);
194 static void start_int_poll_timer(struct controller *ctrl, int sec);
195 
196 /* This is the interrupt polling timeout function. */
197 static void int_poll_timeout(unsigned long data)
198 {
199 	struct controller *ctrl = (struct controller *)data;
200 
201 	/* Poll for interrupt events.  regs == NULL => polling */
202 	pcie_isr(0, ctrl);
203 
204 	init_timer(&ctrl->poll_timer);
205 	if (!pciehp_poll_time)
206 		pciehp_poll_time = 2; /* default polling interval is 2 sec */
207 
208 	start_int_poll_timer(ctrl, pciehp_poll_time);
209 }
210 
211 /* This function starts the interrupt polling timer. */
212 static void start_int_poll_timer(struct controller *ctrl, int sec)
213 {
214 	/* Clamp to sane value */
215 	if ((sec <= 0) || (sec > 60))
216         	sec = 2;
217 
218 	ctrl->poll_timer.function = &int_poll_timeout;
219 	ctrl->poll_timer.data = (unsigned long)ctrl;
220 	ctrl->poll_timer.expires = jiffies + sec * HZ;
221 	add_timer(&ctrl->poll_timer);
222 }
223 
224 static inline int pcie_wait_cmd(struct controller *ctrl)
225 {
226 	int retval = 0;
227 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
228 	unsigned long timeout = msecs_to_jiffies(msecs);
229 	int rc;
230 
231 	rc = wait_event_interruptible_timeout(ctrl->queue,
232 					      !ctrl->cmd_busy, timeout);
233 	if (!rc)
234 		dbg("Command not completed in 1000 msec\n");
235 	else if (rc < 0) {
236 		retval = -EINTR;
237 		info("Command was interrupted by a signal\n");
238 	}
239 
240 	return retval;
241 }
242 
243 /**
244  * pcie_write_cmd - Issue controller command
245  * @slot: slot to which the command is issued
246  * @cmd:  command value written to slot control register
247  * @mask: bitmask of slot control register to be modified
248  */
249 static int pcie_write_cmd(struct slot *slot, u16 cmd, u16 mask)
250 {
251 	struct controller *ctrl = slot->ctrl;
252 	int retval = 0;
253 	u16 slot_status;
254 	u16 slot_ctrl;
255 	unsigned long flags;
256 
257 	mutex_lock(&ctrl->ctrl_lock);
258 
259 	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
260 	if (retval) {
261 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
262 		goto out;
263 	}
264 
265 	if ((slot_status & CMD_COMPLETED) == CMD_COMPLETED ) {
266 		/* After 1 sec and CMD_COMPLETED still not set, just
267 		   proceed forward to issue the next command according
268 		   to spec.  Just print out the error message */
269 		dbg("%s: CMD_COMPLETED not clear after 1 sec.\n",
270 		    __FUNCTION__);
271 	}
272 
273 	spin_lock_irqsave(&ctrl->lock, flags);
274 	retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
275 	if (retval) {
276 		err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
277 		goto out_spin_unlock;
278 	}
279 
280 	slot_ctrl &= ~mask;
281 	slot_ctrl |= ((cmd & mask) | CMD_CMPL_INTR_ENABLE);
282 
283 	ctrl->cmd_busy = 1;
284 	retval = pciehp_writew(ctrl, SLOTCTRL, slot_ctrl);
285 	if (retval)
286 		err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__);
287 
288  out_spin_unlock:
289 	spin_unlock_irqrestore(&ctrl->lock, flags);
290 
291 	/*
292 	 * Wait for command completion.
293 	 */
294 	if (!retval)
295 		retval = pcie_wait_cmd(ctrl);
296  out:
297 	mutex_unlock(&ctrl->ctrl_lock);
298 	return retval;
299 }
300 
301 static int hpc_check_lnk_status(struct controller *ctrl)
302 {
303 	u16 lnk_status;
304 	int retval = 0;
305 
306 	retval = pciehp_readw(ctrl, LNKSTATUS, &lnk_status);
307 	if (retval) {
308 		err("%s: Cannot read LNKSTATUS register\n", __FUNCTION__);
309 		return retval;
310 	}
311 
312 	dbg("%s: lnk_status = %x\n", __FUNCTION__, lnk_status);
313 	if ( (lnk_status & LNK_TRN) || (lnk_status & LNK_TRN_ERR) ||
314 		!(lnk_status & NEG_LINK_WD)) {
315 		err("%s : Link Training Error occurs \n", __FUNCTION__);
316 		retval = -1;
317 		return retval;
318 	}
319 
320 	return retval;
321 }
322 
323 static int hpc_get_attention_status(struct slot *slot, u8 *status)
324 {
325 	struct controller *ctrl = slot->ctrl;
326 	u16 slot_ctrl;
327 	u8 atten_led_state;
328 	int retval = 0;
329 
330 	retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
331 	if (retval) {
332 		err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
333 		return retval;
334 	}
335 
336 	dbg("%s: SLOTCTRL %x, value read %x\n",
337 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_ctrl);
338 
339 	atten_led_state = (slot_ctrl & ATTN_LED_CTRL) >> 6;
340 
341 	switch (atten_led_state) {
342 	case 0:
343 		*status = 0xFF;	/* Reserved */
344 		break;
345 	case 1:
346 		*status = 1;	/* On */
347 		break;
348 	case 2:
349 		*status = 2;	/* Blink */
350 		break;
351 	case 3:
352 		*status = 0;	/* Off */
353 		break;
354 	default:
355 		*status = 0xFF;
356 		break;
357 	}
358 
359 	return 0;
360 }
361 
362 static int hpc_get_power_status(struct slot *slot, u8 *status)
363 {
364 	struct controller *ctrl = slot->ctrl;
365 	u16 slot_ctrl;
366 	u8 pwr_state;
367 	int	retval = 0;
368 
369 	retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
370 	if (retval) {
371 		err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
372 		return retval;
373 	}
374 	dbg("%s: SLOTCTRL %x value read %x\n",
375 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_ctrl);
376 
377 	pwr_state = (slot_ctrl & PWR_CTRL) >> 10;
378 
379 	switch (pwr_state) {
380 	case 0:
381 		*status = 1;
382 		break;
383 	case 1:
384 		*status = 0;
385 		break;
386 	default:
387 		*status = 0xFF;
388 		break;
389 	}
390 
391 	return retval;
392 }
393 
394 static int hpc_get_latch_status(struct slot *slot, u8 *status)
395 {
396 	struct controller *ctrl = slot->ctrl;
397 	u16 slot_status;
398 	int retval = 0;
399 
400 	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
401 	if (retval) {
402 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
403 		return retval;
404 	}
405 
406 	*status = (((slot_status & MRL_STATE) >> 5) == 0) ? 0 : 1;
407 
408 	return 0;
409 }
410 
411 static int hpc_get_adapter_status(struct slot *slot, u8 *status)
412 {
413 	struct controller *ctrl = slot->ctrl;
414 	u16 slot_status;
415 	u8 card_state;
416 	int retval = 0;
417 
418 	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
419 	if (retval) {
420 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
421 		return retval;
422 	}
423 	card_state = (u8)((slot_status & PRSN_STATE) >> 6);
424 	*status = (card_state == 1) ? 1 : 0;
425 
426 	return 0;
427 }
428 
429 static int hpc_query_power_fault(struct slot *slot)
430 {
431 	struct controller *ctrl = slot->ctrl;
432 	u16 slot_status;
433 	u8 pwr_fault;
434 	int retval = 0;
435 
436 	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
437 	if (retval) {
438 		err("%s: Cannot check for power fault\n", __FUNCTION__);
439 		return retval;
440 	}
441 	pwr_fault = (u8)((slot_status & PWR_FAULT_DETECTED) >> 1);
442 
443 	return pwr_fault;
444 }
445 
446 static int hpc_get_emi_status(struct slot *slot, u8 *status)
447 {
448 	struct controller *ctrl = slot->ctrl;
449 	u16 slot_status;
450 	int retval = 0;
451 
452 	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
453 	if (retval) {
454 		err("%s : Cannot check EMI status\n", __FUNCTION__);
455 		return retval;
456 	}
457 	*status = (slot_status & EMI_STATE) >> EMI_STATUS_BIT;
458 
459 	return retval;
460 }
461 
462 static int hpc_toggle_emi(struct slot *slot)
463 {
464 	u16 slot_cmd;
465 	u16 cmd_mask;
466 	int rc;
467 
468 	slot_cmd = EMI_CTRL;
469 	cmd_mask = EMI_CTRL;
470 	if (!pciehp_poll_mode) {
471 		slot_cmd = slot_cmd | HP_INTR_ENABLE;
472 		cmd_mask = cmd_mask | HP_INTR_ENABLE;
473 	}
474 
475 	rc = pcie_write_cmd(slot, slot_cmd, cmd_mask);
476 	slot->last_emi_toggle = get_seconds();
477 
478 	return rc;
479 }
480 
481 static int hpc_set_attention_status(struct slot *slot, u8 value)
482 {
483 	struct controller *ctrl = slot->ctrl;
484 	u16 slot_cmd;
485 	u16 cmd_mask;
486 	int rc;
487 
488 	cmd_mask = ATTN_LED_CTRL;
489 	switch (value) {
490 		case 0 :	/* turn off */
491 			slot_cmd = 0x00C0;
492 			break;
493 		case 1:		/* turn on */
494 			slot_cmd = 0x0040;
495 			break;
496 		case 2:		/* turn blink */
497 			slot_cmd = 0x0080;
498 			break;
499 		default:
500 			return -1;
501 	}
502 	if (!pciehp_poll_mode) {
503 		slot_cmd = slot_cmd | HP_INTR_ENABLE;
504 		cmd_mask = cmd_mask | HP_INTR_ENABLE;
505 	}
506 
507 	rc = pcie_write_cmd(slot, slot_cmd, cmd_mask);
508 	dbg("%s: SLOTCTRL %x write cmd %x\n",
509 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_cmd);
510 
511 	return rc;
512 }
513 
514 static void hpc_set_green_led_on(struct slot *slot)
515 {
516 	struct controller *ctrl = slot->ctrl;
517 	u16 slot_cmd;
518 	u16 cmd_mask;
519 
520 	slot_cmd = 0x0100;
521 	cmd_mask = PWR_LED_CTRL;
522 	if (!pciehp_poll_mode) {
523 		slot_cmd = slot_cmd | HP_INTR_ENABLE;
524 		cmd_mask = cmd_mask | HP_INTR_ENABLE;
525 	}
526 
527 	pcie_write_cmd(slot, slot_cmd, cmd_mask);
528 
529 	dbg("%s: SLOTCTRL %x write cmd %x\n",
530 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_cmd);
531 }
532 
533 static void hpc_set_green_led_off(struct slot *slot)
534 {
535 	struct controller *ctrl = slot->ctrl;
536 	u16 slot_cmd;
537 	u16 cmd_mask;
538 
539 	slot_cmd = 0x0300;
540 	cmd_mask = PWR_LED_CTRL;
541 	if (!pciehp_poll_mode) {
542 		slot_cmd = slot_cmd | HP_INTR_ENABLE;
543 		cmd_mask = cmd_mask | HP_INTR_ENABLE;
544 	}
545 
546 	pcie_write_cmd(slot, slot_cmd, cmd_mask);
547 	dbg("%s: SLOTCTRL %x write cmd %x\n",
548 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_cmd);
549 }
550 
551 static void hpc_set_green_led_blink(struct slot *slot)
552 {
553 	struct controller *ctrl = slot->ctrl;
554 	u16 slot_cmd;
555 	u16 cmd_mask;
556 
557 	slot_cmd = 0x0200;
558 	cmd_mask = PWR_LED_CTRL;
559 	if (!pciehp_poll_mode) {
560 		slot_cmd = slot_cmd | HP_INTR_ENABLE;
561 		cmd_mask = cmd_mask | HP_INTR_ENABLE;
562 	}
563 
564 	pcie_write_cmd(slot, slot_cmd, cmd_mask);
565 
566 	dbg("%s: SLOTCTRL %x write cmd %x\n",
567 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_cmd);
568 }
569 
570 static void hpc_release_ctlr(struct controller *ctrl)
571 {
572 	if (pciehp_poll_mode)
573 		del_timer(&ctrl->poll_timer);
574 	else
575 		free_irq(ctrl->pci_dev->irq, ctrl);
576 
577 	/*
578 	 * If this is the last controller to be released, destroy the
579 	 * pciehp work queue
580 	 */
581 	if (atomic_dec_and_test(&pciehp_num_controllers))
582 		destroy_workqueue(pciehp_wq);
583 }
584 
585 static int hpc_power_on_slot(struct slot * slot)
586 {
587 	struct controller *ctrl = slot->ctrl;
588 	u16 slot_cmd;
589 	u16 cmd_mask;
590 	u16 slot_status;
591 	int retval = 0;
592 
593 	dbg("%s: slot->hp_slot %x\n", __FUNCTION__, slot->hp_slot);
594 
595 	/* Clear sticky power-fault bit from previous power failures */
596 	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
597 	if (retval) {
598 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
599 		return retval;
600 	}
601 	slot_status &= PWR_FAULT_DETECTED;
602 	if (slot_status) {
603 		retval = pciehp_writew(ctrl, SLOTSTATUS, slot_status);
604 		if (retval) {
605 			err("%s: Cannot write to SLOTSTATUS register\n",
606 			    __FUNCTION__);
607 			return retval;
608 		}
609 	}
610 
611 	slot_cmd = POWER_ON;
612 	cmd_mask = PWR_CTRL;
613 	/* Enable detection that we turned off at slot power-off time */
614 	if (!pciehp_poll_mode) {
615 		slot_cmd = slot_cmd |
616 		           PWR_FAULT_DETECT_ENABLE |
617 		           MRL_DETECT_ENABLE |
618 		           PRSN_DETECT_ENABLE |
619 		           HP_INTR_ENABLE;
620 		cmd_mask = cmd_mask |
621 		           PWR_FAULT_DETECT_ENABLE |
622 		           MRL_DETECT_ENABLE |
623 		           PRSN_DETECT_ENABLE |
624 		           HP_INTR_ENABLE;
625 	}
626 
627 	retval = pcie_write_cmd(slot, slot_cmd, cmd_mask);
628 
629 	if (retval) {
630 		err("%s: Write %x command failed!\n", __FUNCTION__, slot_cmd);
631 		return -1;
632 	}
633 	dbg("%s: SLOTCTRL %x write cmd %x\n",
634 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_cmd);
635 
636 	return retval;
637 }
638 
639 static int hpc_power_off_slot(struct slot * slot)
640 {
641 	struct controller *ctrl = slot->ctrl;
642 	u16 slot_cmd;
643 	u16 cmd_mask;
644 	int retval = 0;
645 
646 	dbg("%s: slot->hp_slot %x\n", __FUNCTION__, slot->hp_slot);
647 
648 	slot_cmd = POWER_OFF;
649 	cmd_mask = PWR_CTRL;
650 	/*
651 	 * If we get MRL or presence detect interrupts now, the isr
652 	 * will notice the sticky power-fault bit too and issue power
653 	 * indicator change commands. This will lead to an endless loop
654 	 * of command completions, since the power-fault bit remains on
655 	 * till the slot is powered on again.
656 	 */
657 	if (!pciehp_poll_mode) {
658 		slot_cmd = (slot_cmd &
659 		            ~PWR_FAULT_DETECT_ENABLE &
660 		            ~MRL_DETECT_ENABLE &
661 		            ~PRSN_DETECT_ENABLE) | HP_INTR_ENABLE;
662 		cmd_mask = cmd_mask |
663 			   PWR_FAULT_DETECT_ENABLE |
664 			   MRL_DETECT_ENABLE |
665 			   PRSN_DETECT_ENABLE |
666 			   HP_INTR_ENABLE;
667 	}
668 
669 	retval = pcie_write_cmd(slot, slot_cmd, cmd_mask);
670 	if (retval) {
671 		err("%s: Write command failed!\n", __FUNCTION__);
672 		return -1;
673 	}
674 	dbg("%s: SLOTCTRL %x write cmd %x\n",
675 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_cmd);
676 
677 	return retval;
678 }
679 
680 static irqreturn_t pcie_isr(int irq, void *dev_id)
681 {
682 	struct controller *ctrl = (struct controller *)dev_id;
683 	u16 slot_status, intr_detect, intr_loc;
684 	u16 temp_word;
685 	int hp_slot = 0;	/* only 1 slot per PCI Express port */
686 	int rc = 0;
687 	unsigned long flags;
688 
689 	rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
690 	if (rc) {
691 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
692 		return IRQ_NONE;
693 	}
694 
695 	intr_detect = (ATTN_BUTTN_PRESSED | PWR_FAULT_DETECTED |
696 		       MRL_SENS_CHANGED | PRSN_DETECT_CHANGED | CMD_COMPLETED);
697 
698 	intr_loc = slot_status & intr_detect;
699 
700 	/* Check to see if it was our interrupt */
701 	if ( !intr_loc )
702 		return IRQ_NONE;
703 
704 	dbg("%s: intr_loc %x\n", __FUNCTION__, intr_loc);
705 	/* Mask Hot-plug Interrupt Enable */
706 	if (!pciehp_poll_mode) {
707 		spin_lock_irqsave(&ctrl->lock, flags);
708 		rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
709 		if (rc) {
710 			err("%s: Cannot read SLOT_CTRL register\n",
711 			    __FUNCTION__);
712 			spin_unlock_irqrestore(&ctrl->lock, flags);
713 			return IRQ_NONE;
714 		}
715 
716 		dbg("%s: pciehp_readw(SLOTCTRL) with value %x\n",
717 		    __FUNCTION__, temp_word);
718 		temp_word = (temp_word & ~HP_INTR_ENABLE &
719 			     ~CMD_CMPL_INTR_ENABLE) | 0x00;
720 		rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
721 		if (rc) {
722 			err("%s: Cannot write to SLOTCTRL register\n",
723 			    __FUNCTION__);
724 			spin_unlock_irqrestore(&ctrl->lock, flags);
725 			return IRQ_NONE;
726 		}
727 		spin_unlock_irqrestore(&ctrl->lock, flags);
728 
729 		rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
730 		if (rc) {
731 			err("%s: Cannot read SLOT_STATUS register\n",
732 			    __FUNCTION__);
733 			return IRQ_NONE;
734 		}
735 		dbg("%s: pciehp_readw(SLOTSTATUS) with value %x\n",
736 		    __FUNCTION__, slot_status);
737 
738 		/* Clear command complete interrupt caused by this write */
739 		temp_word = 0x1f;
740 		rc = pciehp_writew(ctrl, SLOTSTATUS, temp_word);
741 		if (rc) {
742 			err("%s: Cannot write to SLOTSTATUS register\n",
743 			    __FUNCTION__);
744 			return IRQ_NONE;
745 		}
746 	}
747 
748 	if (intr_loc & CMD_COMPLETED) {
749 		/*
750 		 * Command Complete Interrupt Pending
751 		 */
752 		ctrl->cmd_busy = 0;
753 		wake_up_interruptible(&ctrl->queue);
754 	}
755 
756 	if (intr_loc & MRL_SENS_CHANGED)
757 		pciehp_handle_switch_change(hp_slot, ctrl);
758 
759 	if (intr_loc & ATTN_BUTTN_PRESSED)
760 		pciehp_handle_attention_button(hp_slot, ctrl);
761 
762 	if (intr_loc & PRSN_DETECT_CHANGED)
763 		pciehp_handle_presence_change(hp_slot, ctrl);
764 
765 	if (intr_loc & PWR_FAULT_DETECTED)
766 		pciehp_handle_power_fault(hp_slot, ctrl);
767 
768 	/* Clear all events after serving them */
769 	temp_word = 0x1F;
770 	rc = pciehp_writew(ctrl, SLOTSTATUS, temp_word);
771 	if (rc) {
772 		err("%s: Cannot write to SLOTSTATUS register\n", __FUNCTION__);
773 		return IRQ_NONE;
774 	}
775 	/* Unmask Hot-plug Interrupt Enable */
776 	if (!pciehp_poll_mode) {
777 		spin_lock_irqsave(&ctrl->lock, flags);
778 		rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
779 		if (rc) {
780 			err("%s: Cannot read SLOTCTRL register\n",
781 			    __FUNCTION__);
782 			spin_unlock_irqrestore(&ctrl->lock, flags);
783 			return IRQ_NONE;
784 		}
785 
786 		dbg("%s: Unmask Hot-plug Interrupt Enable\n", __FUNCTION__);
787 		temp_word = (temp_word & ~HP_INTR_ENABLE) | HP_INTR_ENABLE;
788 
789 		rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
790 		if (rc) {
791 			err("%s: Cannot write to SLOTCTRL register\n",
792 			    __FUNCTION__);
793 			spin_unlock_irqrestore(&ctrl->lock, flags);
794 			return IRQ_NONE;
795 		}
796 		spin_unlock_irqrestore(&ctrl->lock, flags);
797 
798 		rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
799 		if (rc) {
800 			err("%s: Cannot read SLOT_STATUS register\n",
801 			    __FUNCTION__);
802 			return IRQ_NONE;
803 		}
804 
805 		/* Clear command complete interrupt caused by this write */
806 		temp_word = 0x1F;
807 		rc = pciehp_writew(ctrl, SLOTSTATUS, temp_word);
808 		if (rc) {
809 			err("%s: Cannot write to SLOTSTATUS failed\n",
810 			    __FUNCTION__);
811 			return IRQ_NONE;
812 		}
813 		dbg("%s: pciehp_writew(SLOTSTATUS) with value %x\n",
814 		    __FUNCTION__, temp_word);
815 	}
816 
817 	return IRQ_HANDLED;
818 }
819 
820 static int hpc_get_max_lnk_speed(struct slot *slot, enum pci_bus_speed *value)
821 {
822 	struct controller *ctrl = slot->ctrl;
823 	enum pcie_link_speed lnk_speed;
824 	u32	lnk_cap;
825 	int retval = 0;
826 
827 	retval = pciehp_readl(ctrl, LNKCAP, &lnk_cap);
828 	if (retval) {
829 		err("%s: Cannot read LNKCAP register\n", __FUNCTION__);
830 		return retval;
831 	}
832 
833 	switch (lnk_cap & 0x000F) {
834 	case 1:
835 		lnk_speed = PCIE_2PT5GB;
836 		break;
837 	default:
838 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
839 		break;
840 	}
841 
842 	*value = lnk_speed;
843 	dbg("Max link speed = %d\n", lnk_speed);
844 
845 	return retval;
846 }
847 
848 static int hpc_get_max_lnk_width(struct slot *slot,
849 				 enum pcie_link_width *value)
850 {
851 	struct controller *ctrl = slot->ctrl;
852 	enum pcie_link_width lnk_wdth;
853 	u32	lnk_cap;
854 	int retval = 0;
855 
856 	retval = pciehp_readl(ctrl, LNKCAP, &lnk_cap);
857 	if (retval) {
858 		err("%s: Cannot read LNKCAP register\n", __FUNCTION__);
859 		return retval;
860 	}
861 
862 	switch ((lnk_cap & 0x03F0) >> 4){
863 	case 0:
864 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
865 		break;
866 	case 1:
867 		lnk_wdth = PCIE_LNK_X1;
868 		break;
869 	case 2:
870 		lnk_wdth = PCIE_LNK_X2;
871 		break;
872 	case 4:
873 		lnk_wdth = PCIE_LNK_X4;
874 		break;
875 	case 8:
876 		lnk_wdth = PCIE_LNK_X8;
877 		break;
878 	case 12:
879 		lnk_wdth = PCIE_LNK_X12;
880 		break;
881 	case 16:
882 		lnk_wdth = PCIE_LNK_X16;
883 		break;
884 	case 32:
885 		lnk_wdth = PCIE_LNK_X32;
886 		break;
887 	default:
888 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
889 		break;
890 	}
891 
892 	*value = lnk_wdth;
893 	dbg("Max link width = %d\n", lnk_wdth);
894 
895 	return retval;
896 }
897 
898 static int hpc_get_cur_lnk_speed(struct slot *slot, enum pci_bus_speed *value)
899 {
900 	struct controller *ctrl = slot->ctrl;
901 	enum pcie_link_speed lnk_speed = PCI_SPEED_UNKNOWN;
902 	int retval = 0;
903 	u16 lnk_status;
904 
905 	retval = pciehp_readw(ctrl, LNKSTATUS, &lnk_status);
906 	if (retval) {
907 		err("%s: Cannot read LNKSTATUS register\n", __FUNCTION__);
908 		return retval;
909 	}
910 
911 	switch (lnk_status & 0x0F) {
912 	case 1:
913 		lnk_speed = PCIE_2PT5GB;
914 		break;
915 	default:
916 		lnk_speed = PCIE_LNK_SPEED_UNKNOWN;
917 		break;
918 	}
919 
920 	*value = lnk_speed;
921 	dbg("Current link speed = %d\n", lnk_speed);
922 
923 	return retval;
924 }
925 
926 static int hpc_get_cur_lnk_width(struct slot *slot,
927 				 enum pcie_link_width *value)
928 {
929 	struct controller *ctrl = slot->ctrl;
930 	enum pcie_link_width lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
931 	int retval = 0;
932 	u16 lnk_status;
933 
934 	retval = pciehp_readw(ctrl, LNKSTATUS, &lnk_status);
935 	if (retval) {
936 		err("%s: Cannot read LNKSTATUS register\n", __FUNCTION__);
937 		return retval;
938 	}
939 
940 	switch ((lnk_status & 0x03F0) >> 4){
941 	case 0:
942 		lnk_wdth = PCIE_LNK_WIDTH_RESRV;
943 		break;
944 	case 1:
945 		lnk_wdth = PCIE_LNK_X1;
946 		break;
947 	case 2:
948 		lnk_wdth = PCIE_LNK_X2;
949 		break;
950 	case 4:
951 		lnk_wdth = PCIE_LNK_X4;
952 		break;
953 	case 8:
954 		lnk_wdth = PCIE_LNK_X8;
955 		break;
956 	case 12:
957 		lnk_wdth = PCIE_LNK_X12;
958 		break;
959 	case 16:
960 		lnk_wdth = PCIE_LNK_X16;
961 		break;
962 	case 32:
963 		lnk_wdth = PCIE_LNK_X32;
964 		break;
965 	default:
966 		lnk_wdth = PCIE_LNK_WIDTH_UNKNOWN;
967 		break;
968 	}
969 
970 	*value = lnk_wdth;
971 	dbg("Current link width = %d\n", lnk_wdth);
972 
973 	return retval;
974 }
975 
976 static struct hpc_ops pciehp_hpc_ops = {
977 	.power_on_slot			= hpc_power_on_slot,
978 	.power_off_slot			= hpc_power_off_slot,
979 	.set_attention_status		= hpc_set_attention_status,
980 	.get_power_status		= hpc_get_power_status,
981 	.get_attention_status		= hpc_get_attention_status,
982 	.get_latch_status		= hpc_get_latch_status,
983 	.get_adapter_status		= hpc_get_adapter_status,
984 	.get_emi_status			= hpc_get_emi_status,
985 	.toggle_emi			= hpc_toggle_emi,
986 
987 	.get_max_bus_speed		= hpc_get_max_lnk_speed,
988 	.get_cur_bus_speed		= hpc_get_cur_lnk_speed,
989 	.get_max_lnk_width		= hpc_get_max_lnk_width,
990 	.get_cur_lnk_width		= hpc_get_cur_lnk_width,
991 
992 	.query_power_fault		= hpc_query_power_fault,
993 	.green_led_on			= hpc_set_green_led_on,
994 	.green_led_off			= hpc_set_green_led_off,
995 	.green_led_blink		= hpc_set_green_led_blink,
996 
997 	.release_ctlr			= hpc_release_ctlr,
998 	.check_lnk_status		= hpc_check_lnk_status,
999 };
1000 
1001 #ifdef CONFIG_ACPI
1002 int pciehp_acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev)
1003 {
1004 	acpi_status status;
1005 	acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
1006 	struct pci_dev *pdev = dev;
1007 	struct pci_bus *parent;
1008 	struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
1009 
1010 	/*
1011 	 * Per PCI firmware specification, we should run the ACPI _OSC
1012 	 * method to get control of hotplug hardware before using it.
1013 	 * If an _OSC is missing, we look for an OSHP to do the same thing.
1014 	 * To handle different BIOS behavior, we look for _OSC and OSHP
1015 	 * within the scope of the hotplug controller and its parents, upto
1016 	 * the host bridge under which this controller exists.
1017 	 */
1018 	while (!handle) {
1019 		/*
1020 		 * This hotplug controller was not listed in the ACPI name
1021 		 * space at all. Try to get acpi handle of parent pci bus.
1022 		 */
1023 		if (!pdev || !pdev->bus->parent)
1024 			break;
1025 		parent = pdev->bus->parent;
1026 		dbg("Could not find %s in acpi namespace, trying parent\n",
1027 				pci_name(pdev));
1028 		if (!parent->self)
1029 			/* Parent must be a host bridge */
1030 			handle = acpi_get_pci_rootbridge_handle(
1031 					pci_domain_nr(parent),
1032 					parent->number);
1033 		else
1034 			handle = DEVICE_ACPI_HANDLE(
1035 					&(parent->self->dev));
1036 		pdev = parent->self;
1037 	}
1038 
1039 	while (handle) {
1040 		acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
1041 		dbg("Trying to get hotplug control for %s \n",
1042 			(char *)string.pointer);
1043 		status = pci_osc_control_set(handle,
1044 				OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL |
1045 				OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
1046 		if (status == AE_NOT_FOUND)
1047 			status = acpi_run_oshp(handle);
1048 		if (ACPI_SUCCESS(status)) {
1049 			dbg("Gained control for hotplug HW for pci %s (%s)\n",
1050 				pci_name(dev), (char *)string.pointer);
1051 			kfree(string.pointer);
1052 			return 0;
1053 		}
1054 		if (acpi_root_bridge(handle))
1055 			break;
1056 		chandle = handle;
1057 		status = acpi_get_parent(chandle, &handle);
1058 		if (ACPI_FAILURE(status))
1059 			break;
1060 	}
1061 
1062 	err("Cannot get control of hotplug hardware for pci %s\n",
1063 			pci_name(dev));
1064 
1065 	kfree(string.pointer);
1066 	return -1;
1067 }
1068 #endif
1069 
1070 int pcie_init(struct controller * ctrl, struct pcie_device *dev)
1071 {
1072 	int rc;
1073 	u16 temp_word;
1074 	u16 cap_reg;
1075 	u16 intr_enable = 0;
1076 	u32 slot_cap;
1077 	int cap_base;
1078 	u16 slot_status, slot_ctrl;
1079 	struct pci_dev *pdev;
1080 
1081 	pdev = dev->port;
1082 	ctrl->pci_dev = pdev;	/* save pci_dev in context */
1083 
1084 	dbg("%s: hotplug controller vendor id 0x%x device id 0x%x\n",
1085 			__FUNCTION__, pdev->vendor, pdev->device);
1086 
1087 	if ((cap_base = pci_find_capability(pdev, PCI_CAP_ID_EXP)) == 0) {
1088 		dbg("%s: Can't find PCI_CAP_ID_EXP (0x10)\n", __FUNCTION__);
1089 		goto abort_free_ctlr;
1090 	}
1091 
1092 	ctrl->cap_base = cap_base;
1093 
1094 	dbg("%s: pcie_cap_base %x\n", __FUNCTION__, cap_base);
1095 
1096 	rc = pciehp_readw(ctrl, CAPREG, &cap_reg);
1097 	if (rc) {
1098 		err("%s: Cannot read CAPREG register\n", __FUNCTION__);
1099 		goto abort_free_ctlr;
1100 	}
1101 	dbg("%s: CAPREG offset %x cap_reg %x\n",
1102 	    __FUNCTION__, ctrl->cap_base + CAPREG, cap_reg);
1103 
1104 	if (((cap_reg & SLOT_IMPL) == 0) ||
1105 	    (((cap_reg & DEV_PORT_TYPE) != 0x0040)
1106 		&& ((cap_reg & DEV_PORT_TYPE) != 0x0060))) {
1107 		dbg("%s : This is not a root port or the port is not "
1108 		    "connected to a slot\n", __FUNCTION__);
1109 		goto abort_free_ctlr;
1110 	}
1111 
1112 	rc = pciehp_readl(ctrl, SLOTCAP, &slot_cap);
1113 	if (rc) {
1114 		err("%s: Cannot read SLOTCAP register\n", __FUNCTION__);
1115 		goto abort_free_ctlr;
1116 	}
1117 	dbg("%s: SLOTCAP offset %x slot_cap %x\n",
1118 	    __FUNCTION__, ctrl->cap_base + SLOTCAP, slot_cap);
1119 
1120 	if (!(slot_cap & HP_CAP)) {
1121 		dbg("%s : This slot is not hot-plug capable\n", __FUNCTION__);
1122 		goto abort_free_ctlr;
1123 	}
1124 	/* For debugging purpose */
1125 	rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
1126 	if (rc) {
1127 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
1128 		goto abort_free_ctlr;
1129 	}
1130 	dbg("%s: SLOTSTATUS offset %x slot_status %x\n",
1131 	    __FUNCTION__, ctrl->cap_base + SLOTSTATUS, slot_status);
1132 
1133 	rc = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
1134 	if (rc) {
1135 		err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
1136 		goto abort_free_ctlr;
1137 	}
1138 	dbg("%s: SLOTCTRL offset %x slot_ctrl %x\n",
1139 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_ctrl);
1140 
1141 	for (rc = 0; rc < DEVICE_COUNT_RESOURCE; rc++)
1142 		if (pci_resource_len(pdev, rc) > 0)
1143 			dbg("pci resource[%d] start=0x%llx(len=0x%llx)\n", rc,
1144 			    (unsigned long long)pci_resource_start(pdev, rc),
1145 			    (unsigned long long)pci_resource_len(pdev, rc));
1146 
1147 	info("HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
1148 	     pdev->vendor, pdev->device,
1149 	     pdev->subsystem_vendor, pdev->subsystem_device);
1150 
1151 	mutex_init(&ctrl->crit_sect);
1152 	mutex_init(&ctrl->ctrl_lock);
1153 	spin_lock_init(&ctrl->lock);
1154 
1155 	/* setup wait queue */
1156 	init_waitqueue_head(&ctrl->queue);
1157 
1158 	/* return PCI Controller Info */
1159 	ctrl->slot_device_offset = 0;
1160 	ctrl->num_slots = 1;
1161 	ctrl->first_slot = slot_cap >> 19;
1162 	ctrl->ctrlcap = slot_cap & 0x0000007f;
1163 
1164 	/* Mask Hot-plug Interrupt Enable */
1165 	rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
1166 	if (rc) {
1167 		err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
1168 		goto abort_free_ctlr;
1169 	}
1170 
1171 	dbg("%s: SLOTCTRL %x value read %x\n",
1172 	    __FUNCTION__, ctrl->cap_base + SLOTCTRL, temp_word);
1173 	temp_word = (temp_word & ~HP_INTR_ENABLE & ~CMD_CMPL_INTR_ENABLE) |
1174 		0x00;
1175 
1176 	rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
1177 	if (rc) {
1178 		err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__);
1179 		goto abort_free_ctlr;
1180 	}
1181 
1182 	rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
1183 	if (rc) {
1184 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
1185 		goto abort_free_ctlr;
1186 	}
1187 
1188 	temp_word = 0x1F; /* Clear all events */
1189 	rc = pciehp_writew(ctrl, SLOTSTATUS, temp_word);
1190 	if (rc) {
1191 		err("%s: Cannot write to SLOTSTATUS register\n", __FUNCTION__);
1192 		goto abort_free_ctlr;
1193 	}
1194 
1195 	if (pciehp_poll_mode) {
1196 		/* Install interrupt polling timer. Start with 10 sec delay */
1197 		init_timer(&ctrl->poll_timer);
1198 		start_int_poll_timer(ctrl, 10);
1199 	} else {
1200 		/* Installs the interrupt handler */
1201 		rc = request_irq(ctrl->pci_dev->irq, pcie_isr, IRQF_SHARED,
1202 				 MY_NAME, (void *)ctrl);
1203 		dbg("%s: request_irq %d for hpc%d (returns %d)\n",
1204 		    __FUNCTION__, ctrl->pci_dev->irq,
1205 		    atomic_read(&pciehp_num_controllers), rc);
1206 		if (rc) {
1207 			err("Can't get irq %d for the hotplug controller\n",
1208 			    ctrl->pci_dev->irq);
1209 			goto abort_free_ctlr;
1210 		}
1211 	}
1212 	dbg("pciehp ctrl b:d:f:irq=0x%x:%x:%x:%x\n", pdev->bus->number,
1213 		PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn), dev->irq);
1214 
1215 	/*
1216 	 * If this is the first controller to be initialized,
1217 	 * initialize the pciehp work queue
1218 	 */
1219 	if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
1220 		pciehp_wq = create_singlethread_workqueue("pciehpd");
1221 		if (!pciehp_wq) {
1222 			rc = -ENOMEM;
1223 			goto abort_free_irq;
1224 		}
1225 	}
1226 
1227 	rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
1228 	if (rc) {
1229 		err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
1230 		goto abort_free_irq;
1231 	}
1232 
1233 	intr_enable = intr_enable | PRSN_DETECT_ENABLE;
1234 
1235 	if (ATTN_BUTTN(slot_cap))
1236 		intr_enable = intr_enable | ATTN_BUTTN_ENABLE;
1237 
1238 	if (POWER_CTRL(slot_cap))
1239 		intr_enable = intr_enable | PWR_FAULT_DETECT_ENABLE;
1240 
1241 	if (MRL_SENS(slot_cap))
1242 		intr_enable = intr_enable | MRL_DETECT_ENABLE;
1243 
1244 	temp_word = (temp_word & ~intr_enable) | intr_enable;
1245 
1246 	if (pciehp_poll_mode) {
1247 		temp_word = (temp_word & ~HP_INTR_ENABLE) | 0x0;
1248 	} else {
1249 		temp_word = (temp_word & ~HP_INTR_ENABLE) | HP_INTR_ENABLE;
1250 	}
1251 
1252 	/*
1253 	 * Unmask Hot-plug Interrupt Enable for the interrupt
1254 	 * notification mechanism case.
1255 	 */
1256 	rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
1257 	if (rc) {
1258 		err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__);
1259 		goto abort_free_irq;
1260 	}
1261 	rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
1262 	if (rc) {
1263 		err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
1264 		goto abort_disable_intr;
1265 	}
1266 
1267 	temp_word =  0x1F; /* Clear all events */
1268 	rc = pciehp_writew(ctrl, SLOTSTATUS, temp_word);
1269 	if (rc) {
1270 		err("%s: Cannot write to SLOTSTATUS register\n", __FUNCTION__);
1271 		goto abort_disable_intr;
1272 	}
1273 
1274 	if (pciehp_force) {
1275 		dbg("Bypassing BIOS check for pciehp use on %s\n",
1276 				pci_name(ctrl->pci_dev));
1277 	} else {
1278 		rc = pciehp_get_hp_hw_control_from_firmware(ctrl->pci_dev);
1279 		if (rc)
1280 			goto abort_disable_intr;
1281 	}
1282 
1283 	ctrl->hpc_ops = &pciehp_hpc_ops;
1284 
1285 	return 0;
1286 
1287 	/* We end up here for the many possible ways to fail this API. */
1288 abort_disable_intr:
1289 	rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
1290 	if (!rc) {
1291 		temp_word &= ~(intr_enable | HP_INTR_ENABLE);
1292 		rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
1293 	}
1294 	if (rc)
1295 		err("%s : disabling interrupts failed\n", __FUNCTION__);
1296 
1297 abort_free_irq:
1298 	if (pciehp_poll_mode)
1299 		del_timer_sync(&ctrl->poll_timer);
1300 	else
1301 		free_irq(ctrl->pci_dev->irq, ctrl);
1302 
1303 abort_free_ctlr:
1304 	return -1;
1305 }
1306