xref: /linux/drivers/pci/hotplug/ibmphp_hpc.c (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * IBM Hot Plug Controller Driver
4  *
5  * Written By: Jyoti Shah, IBM Corporation
6  *
7  * Copyright (C) 2001-2003 IBM Corp.
8  *
9  * All rights reserved.
10  *
11  * Send feedback to <gregkh@us.ibm.com>
12  *                  <jshah@us.ibm.com>
13  *
14  */
15 
16 #include <linux/wait.h>
17 #include <linux/time.h>
18 #include <linux/completion.h>
19 #include <linux/delay.h>
20 #include <linux/module.h>
21 #include <linux/pci.h>
22 #include <linux/init.h>
23 #include <linux/mutex.h>
24 #include <linux/sched.h>
25 #include <linux/kthread.h>
26 #include "ibmphp.h"
27 
28 static int to_debug = 0;
29 #define debug_polling(fmt, arg...)	do { if (to_debug) debug(fmt, arg); } while (0)
30 
31 //----------------------------------------------------------------------------
32 // timeout values
33 //----------------------------------------------------------------------------
34 #define CMD_COMPLETE_TOUT_SEC	60	// give HPC 60 sec to finish cmd
35 #define HPC_CTLR_WORKING_TOUT	60	// give HPC 60 sec to finish cmd
36 #define HPC_GETACCESS_TIMEOUT	60	// seconds
37 #define POLL_INTERVAL_SEC	2	// poll HPC every 2 seconds
38 #define POLL_LATCH_CNT		5	// poll latch 5 times, then poll slots
39 
40 //----------------------------------------------------------------------------
41 // Winnipeg Architected Register Offsets
42 //----------------------------------------------------------------------------
43 #define WPG_I2CMBUFL_OFFSET	0x08	// I2C Message Buffer Low
44 #define WPG_I2CMOSUP_OFFSET	0x10	// I2C Master Operation Setup Reg
45 #define WPG_I2CMCNTL_OFFSET	0x20	// I2C Master Control Register
46 #define WPG_I2CPARM_OFFSET	0x40	// I2C Parameter Register
47 #define WPG_I2CSTAT_OFFSET	0x70	// I2C Status Register
48 
49 //----------------------------------------------------------------------------
50 // Winnipeg Store Type commands (Add this commands to the register offset)
51 //----------------------------------------------------------------------------
52 #define WPG_I2C_AND		0x1000	// I2C AND operation
53 #define WPG_I2C_OR		0x2000	// I2C OR operation
54 
55 //----------------------------------------------------------------------------
56 // Command set for I2C Master Operation Setup Register
57 //----------------------------------------------------------------------------
58 #define WPG_READATADDR_MASK	0x00010000	// read,bytes,I2C shifted,index
59 #define WPG_WRITEATADDR_MASK	0x40010000	// write,bytes,I2C shifted,index
60 #define WPG_READDIRECT_MASK	0x10010000
61 #define WPG_WRITEDIRECT_MASK	0x60010000
62 
63 
64 //----------------------------------------------------------------------------
65 // bit masks for I2C Master Control Register
66 //----------------------------------------------------------------------------
67 #define WPG_I2CMCNTL_STARTOP_MASK	0x00000002	// Start the Operation
68 
69 //----------------------------------------------------------------------------
70 //
71 //----------------------------------------------------------------------------
72 #define WPG_I2C_IOREMAP_SIZE	0x2044	// size of linear address interval
73 
74 //----------------------------------------------------------------------------
75 // command index
76 //----------------------------------------------------------------------------
77 #define WPG_1ST_SLOT_INDEX	0x01	// index - 1st slot for ctlr
78 #define WPG_CTLR_INDEX		0x0F	// index - ctlr
79 #define WPG_1ST_EXTSLOT_INDEX	0x10	// index - 1st ext slot for ctlr
80 #define WPG_1ST_BUS_INDEX	0x1F	// index - 1st bus for ctlr
81 
82 //----------------------------------------------------------------------------
83 // macro utilities
84 //----------------------------------------------------------------------------
85 // if bits 20,22,25,26,27,29,30 are OFF return 1
86 #define HPC_I2CSTATUS_CHECK(s)	((u8)((s & 0x00000A76) ? 0 : 1))
87 
88 //----------------------------------------------------------------------------
89 // global variables
90 //----------------------------------------------------------------------------
91 static DEFINE_MUTEX(sem_hpcaccess);	// lock access to HPC
92 static DEFINE_MUTEX(operations_mutex);	// lock all operations and
93 					// access to data structures
94 static DECLARE_COMPLETION(exit_complete); // make sure polling thread goes away
95 static struct task_struct *ibmphp_poll_thread;
96 //----------------------------------------------------------------------------
97 // local function prototypes
98 //----------------------------------------------------------------------------
99 static u8 i2c_ctrl_read(struct controller *, void __iomem *, u8);
100 static u8 i2c_ctrl_write(struct controller *, void __iomem *, u8, u8);
101 static u8 hpc_writecmdtoindex(u8, u8);
102 static u8 hpc_readcmdtoindex(u8, u8);
103 static void get_hpc_access(void);
104 static void free_hpc_access(void);
105 static int poll_hpc(void *data);
106 static int process_changeinstatus(struct slot *, struct slot *);
107 static int process_changeinlatch(u8, u8, struct controller *);
108 static int hpc_wait_ctlr_notworking(int, struct controller *, void __iomem *, u8 *);
109 //----------------------------------------------------------------------------
110 
111 
112 /*----------------------------------------------------------------------
113 * Name:    i2c_ctrl_read
114 *
115 * Action:  read from HPC over I2C
116 *
117 *---------------------------------------------------------------------*/
118 static u8 i2c_ctrl_read(struct controller *ctlr_ptr, void __iomem *WPGBbar, u8 index)
119 {
120 	u8 status;
121 	int i;
122 	void __iomem *wpg_addr;	// base addr + offset
123 	unsigned long wpg_data;	// data to/from WPG LOHI format
124 	unsigned long ultemp;
125 	unsigned long data;	// actual data HILO format
126 
127 	debug_polling("%s - Entry WPGBbar[%p] index[%x] \n", __func__, WPGBbar, index);
128 
129 	//--------------------------------------------------------------------
130 	// READ - step 1
131 	// read at address, byte length, I2C address (shifted), index
132 	// or read direct, byte length, index
133 	if (ctlr_ptr->ctlr_type == 0x02) {
134 		data = WPG_READATADDR_MASK;
135 		// fill in I2C address
136 		ultemp = (unsigned long)ctlr_ptr->u.wpeg_ctlr.i2c_addr;
137 		ultemp = ultemp >> 1;
138 		data |= (ultemp << 8);
139 
140 		// fill in index
141 		data |= (unsigned long)index;
142 	} else if (ctlr_ptr->ctlr_type == 0x04) {
143 		data = WPG_READDIRECT_MASK;
144 
145 		// fill in index
146 		ultemp = (unsigned long)index;
147 		ultemp = ultemp << 8;
148 		data |= ultemp;
149 	} else {
150 		err("this controller type is not supported \n");
151 		return HPC_ERROR;
152 	}
153 
154 	wpg_data = swab32(data);	// swap data before writing
155 	wpg_addr = WPGBbar + WPG_I2CMOSUP_OFFSET;
156 	writel(wpg_data, wpg_addr);
157 
158 	//--------------------------------------------------------------------
159 	// READ - step 2 : clear the message buffer
160 	data = 0x00000000;
161 	wpg_data = swab32(data);
162 	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
163 	writel(wpg_data, wpg_addr);
164 
165 	//--------------------------------------------------------------------
166 	// READ - step 3 : issue start operation, I2C master control bit 30:ON
167 	//                 2020 : [20] OR operation at [20] offset 0x20
168 	data = WPG_I2CMCNTL_STARTOP_MASK;
169 	wpg_data = swab32(data);
170 	wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET + WPG_I2C_OR;
171 	writel(wpg_data, wpg_addr);
172 
173 	//--------------------------------------------------------------------
174 	// READ - step 4 : wait until start operation bit clears
175 	i = CMD_COMPLETE_TOUT_SEC;
176 	while (i) {
177 		msleep(10);
178 		wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET;
179 		wpg_data = readl(wpg_addr);
180 		data = swab32(wpg_data);
181 		if (!(data & WPG_I2CMCNTL_STARTOP_MASK))
182 			break;
183 		i--;
184 	}
185 	if (i == 0) {
186 		debug("%s - Error : WPG timeout\n", __func__);
187 		return HPC_ERROR;
188 	}
189 	//--------------------------------------------------------------------
190 	// READ - step 5 : read I2C status register
191 	i = CMD_COMPLETE_TOUT_SEC;
192 	while (i) {
193 		msleep(10);
194 		wpg_addr = WPGBbar + WPG_I2CSTAT_OFFSET;
195 		wpg_data = readl(wpg_addr);
196 		data = swab32(wpg_data);
197 		if (HPC_I2CSTATUS_CHECK(data))
198 			break;
199 		i--;
200 	}
201 	if (i == 0) {
202 		debug("ctrl_read - Exit Error:I2C timeout\n");
203 		return HPC_ERROR;
204 	}
205 
206 	//--------------------------------------------------------------------
207 	// READ - step 6 : get DATA
208 	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
209 	wpg_data = readl(wpg_addr);
210 	data = swab32(wpg_data);
211 
212 	status = (u8) data;
213 
214 	debug_polling("%s - Exit index[%x] status[%x]\n", __func__, index, status);
215 
216 	return (status);
217 }
218 
219 /*----------------------------------------------------------------------
220 * Name:    i2c_ctrl_write
221 *
222 * Action:  write to HPC over I2C
223 *
224 * Return   0 or error codes
225 *---------------------------------------------------------------------*/
226 static u8 i2c_ctrl_write(struct controller *ctlr_ptr, void __iomem *WPGBbar, u8 index, u8 cmd)
227 {
228 	u8 rc;
229 	void __iomem *wpg_addr;	// base addr + offset
230 	unsigned long wpg_data;	// data to/from WPG LOHI format
231 	unsigned long ultemp;
232 	unsigned long data;	// actual data HILO format
233 	int i;
234 
235 	debug_polling("%s - Entry WPGBbar[%p] index[%x] cmd[%x]\n", __func__, WPGBbar, index, cmd);
236 
237 	rc = 0;
238 	//--------------------------------------------------------------------
239 	// WRITE - step 1
240 	// write at address, byte length, I2C address (shifted), index
241 	// or write direct, byte length, index
242 	data = 0x00000000;
243 
244 	if (ctlr_ptr->ctlr_type == 0x02) {
245 		data = WPG_WRITEATADDR_MASK;
246 		// fill in I2C address
247 		ultemp = (unsigned long)ctlr_ptr->u.wpeg_ctlr.i2c_addr;
248 		ultemp = ultemp >> 1;
249 		data |= (ultemp << 8);
250 
251 		// fill in index
252 		data |= (unsigned long)index;
253 	} else if (ctlr_ptr->ctlr_type == 0x04) {
254 		data = WPG_WRITEDIRECT_MASK;
255 
256 		// fill in index
257 		ultemp = (unsigned long)index;
258 		ultemp = ultemp << 8;
259 		data |= ultemp;
260 	} else {
261 		err("this controller type is not supported \n");
262 		return HPC_ERROR;
263 	}
264 
265 	wpg_data = swab32(data);	// swap data before writing
266 	wpg_addr = WPGBbar + WPG_I2CMOSUP_OFFSET;
267 	writel(wpg_data, wpg_addr);
268 
269 	//--------------------------------------------------------------------
270 	// WRITE - step 2 : clear the message buffer
271 	data = 0x00000000 | (unsigned long)cmd;
272 	wpg_data = swab32(data);
273 	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
274 	writel(wpg_data, wpg_addr);
275 
276 	//--------------------------------------------------------------------
277 	// WRITE - step 3 : issue start operation,I2C master control bit 30:ON
278 	//                 2020 : [20] OR operation at [20] offset 0x20
279 	data = WPG_I2CMCNTL_STARTOP_MASK;
280 	wpg_data = swab32(data);
281 	wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET + WPG_I2C_OR;
282 	writel(wpg_data, wpg_addr);
283 
284 	//--------------------------------------------------------------------
285 	// WRITE - step 4 : wait until start operation bit clears
286 	i = CMD_COMPLETE_TOUT_SEC;
287 	while (i) {
288 		msleep(10);
289 		wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET;
290 		wpg_data = readl(wpg_addr);
291 		data = swab32(wpg_data);
292 		if (!(data & WPG_I2CMCNTL_STARTOP_MASK))
293 			break;
294 		i--;
295 	}
296 	if (i == 0) {
297 		debug("%s - Exit Error:WPG timeout\n", __func__);
298 		rc = HPC_ERROR;
299 	}
300 
301 	//--------------------------------------------------------------------
302 	// WRITE - step 5 : read I2C status register
303 	i = CMD_COMPLETE_TOUT_SEC;
304 	while (i) {
305 		msleep(10);
306 		wpg_addr = WPGBbar + WPG_I2CSTAT_OFFSET;
307 		wpg_data = readl(wpg_addr);
308 		data = swab32(wpg_data);
309 		if (HPC_I2CSTATUS_CHECK(data))
310 			break;
311 		i--;
312 	}
313 	if (i == 0) {
314 		debug("ctrl_read - Error : I2C timeout\n");
315 		rc = HPC_ERROR;
316 	}
317 
318 	debug_polling("%s Exit rc[%x]\n", __func__, rc);
319 	return (rc);
320 }
321 
322 //------------------------------------------------------------
323 //  Read from ISA type HPC
324 //------------------------------------------------------------
325 static u8 isa_ctrl_read(struct controller *ctlr_ptr, u8 offset)
326 {
327 	u16 start_address;
328 	u8 data;
329 
330 	start_address = ctlr_ptr->u.isa_ctlr.io_start;
331 	data = inb(start_address + offset);
332 	return data;
333 }
334 
335 //--------------------------------------------------------------
336 // Write to ISA type HPC
337 //--------------------------------------------------------------
338 static void isa_ctrl_write(struct controller *ctlr_ptr, u8 offset, u8 data)
339 {
340 	u16 start_address;
341 	u16 port_address;
342 
343 	start_address = ctlr_ptr->u.isa_ctlr.io_start;
344 	port_address = start_address + (u16) offset;
345 	outb(data, port_address);
346 }
347 
348 static u8 pci_ctrl_read(struct controller *ctrl, u8 offset)
349 {
350 	u8 data = 0x00;
351 	debug("inside pci_ctrl_read\n");
352 	if (ctrl->ctrl_dev)
353 		pci_read_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, &data);
354 	return data;
355 }
356 
357 static u8 pci_ctrl_write(struct controller *ctrl, u8 offset, u8 data)
358 {
359 	u8 rc = -ENODEV;
360 	debug("inside pci_ctrl_write\n");
361 	if (ctrl->ctrl_dev) {
362 		pci_write_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, data);
363 		rc = 0;
364 	}
365 	return rc;
366 }
367 
368 static u8 ctrl_read(struct controller *ctlr, void __iomem *base, u8 offset)
369 {
370 	u8 rc;
371 	switch (ctlr->ctlr_type) {
372 	case 0:
373 		rc = isa_ctrl_read(ctlr, offset);
374 		break;
375 	case 1:
376 		rc = pci_ctrl_read(ctlr, offset);
377 		break;
378 	case 2:
379 	case 4:
380 		rc = i2c_ctrl_read(ctlr, base, offset);
381 		break;
382 	default:
383 		return -ENODEV;
384 	}
385 	return rc;
386 }
387 
388 static u8 ctrl_write(struct controller *ctlr, void __iomem *base, u8 offset, u8 data)
389 {
390 	u8 rc = 0;
391 	switch (ctlr->ctlr_type) {
392 	case 0:
393 		isa_ctrl_write(ctlr, offset, data);
394 		break;
395 	case 1:
396 		rc = pci_ctrl_write(ctlr, offset, data);
397 		break;
398 	case 2:
399 	case 4:
400 		rc = i2c_ctrl_write(ctlr, base, offset, data);
401 		break;
402 	default:
403 		return -ENODEV;
404 	}
405 	return rc;
406 }
407 /*----------------------------------------------------------------------
408 * Name:    hpc_writecmdtoindex()
409 *
410 * Action:  convert a write command to proper index within a controller
411 *
412 * Return   index, HPC_ERROR
413 *---------------------------------------------------------------------*/
414 static u8 hpc_writecmdtoindex(u8 cmd, u8 index)
415 {
416 	u8 rc;
417 
418 	switch (cmd) {
419 	case HPC_CTLR_ENABLEIRQ:	// 0x00.N.15
420 	case HPC_CTLR_CLEARIRQ:	// 0x06.N.15
421 	case HPC_CTLR_RESET:	// 0x07.N.15
422 	case HPC_CTLR_IRQSTEER:	// 0x08.N.15
423 	case HPC_CTLR_DISABLEIRQ:	// 0x01.N.15
424 	case HPC_ALLSLOT_ON:	// 0x11.N.15
425 	case HPC_ALLSLOT_OFF:	// 0x12.N.15
426 		rc = 0x0F;
427 		break;
428 
429 	case HPC_SLOT_OFF:	// 0x02.Y.0-14
430 	case HPC_SLOT_ON:	// 0x03.Y.0-14
431 	case HPC_SLOT_ATTNOFF:	// 0x04.N.0-14
432 	case HPC_SLOT_ATTNON:	// 0x05.N.0-14
433 	case HPC_SLOT_BLINKLED:	// 0x13.N.0-14
434 		rc = index;
435 		break;
436 
437 	case HPC_BUS_33CONVMODE:
438 	case HPC_BUS_66CONVMODE:
439 	case HPC_BUS_66PCIXMODE:
440 	case HPC_BUS_100PCIXMODE:
441 	case HPC_BUS_133PCIXMODE:
442 		rc = index + WPG_1ST_BUS_INDEX - 1;
443 		break;
444 
445 	default:
446 		err("hpc_writecmdtoindex - Error invalid cmd[%x]\n", cmd);
447 		rc = HPC_ERROR;
448 	}
449 
450 	return rc;
451 }
452 
453 /*----------------------------------------------------------------------
454 * Name:    hpc_readcmdtoindex()
455 *
456 * Action:  convert a read command to proper index within a controller
457 *
458 * Return   index, HPC_ERROR
459 *---------------------------------------------------------------------*/
460 static u8 hpc_readcmdtoindex(u8 cmd, u8 index)
461 {
462 	u8 rc;
463 
464 	switch (cmd) {
465 	case READ_CTLRSTATUS:
466 		rc = 0x0F;
467 		break;
468 	case READ_SLOTSTATUS:
469 	case READ_ALLSTAT:
470 		rc = index;
471 		break;
472 	case READ_EXTSLOTSTATUS:
473 		rc = index + WPG_1ST_EXTSLOT_INDEX;
474 		break;
475 	case READ_BUSSTATUS:
476 		rc = index + WPG_1ST_BUS_INDEX - 1;
477 		break;
478 	case READ_SLOTLATCHLOWREG:
479 		rc = 0x28;
480 		break;
481 	case READ_REVLEVEL:
482 		rc = 0x25;
483 		break;
484 	case READ_HPCOPTIONS:
485 		rc = 0x27;
486 		break;
487 	default:
488 		rc = HPC_ERROR;
489 	}
490 	return rc;
491 }
492 
493 /*----------------------------------------------------------------------
494 * Name:    HPCreadslot()
495 *
496 * Action:  issue a READ command to HPC
497 *
498 * Input:   pslot   - cannot be NULL for READ_ALLSTAT
499 *          pstatus - can be NULL for READ_ALLSTAT
500 *
501 * Return   0 or error codes
502 *---------------------------------------------------------------------*/
503 int ibmphp_hpc_readslot(struct slot *pslot, u8 cmd, u8 *pstatus)
504 {
505 	void __iomem *wpg_bbar = NULL;
506 	struct controller *ctlr_ptr;
507 	u8 index, status;
508 	int rc = 0;
509 	int busindex;
510 
511 	debug_polling("%s - Entry pslot[%p] cmd[%x] pstatus[%p]\n", __func__, pslot, cmd, pstatus);
512 
513 	if ((pslot == NULL)
514 	    || ((pstatus == NULL) && (cmd != READ_ALLSTAT) && (cmd != READ_BUSSTATUS))) {
515 		rc = -EINVAL;
516 		err("%s - Error invalid pointer, rc[%d]\n", __func__, rc);
517 		return rc;
518 	}
519 
520 	if (cmd == READ_BUSSTATUS) {
521 		busindex = ibmphp_get_bus_index(pslot->bus);
522 		if (busindex < 0) {
523 			rc = -EINVAL;
524 			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
525 			return rc;
526 		} else
527 			index = (u8) busindex;
528 	} else
529 		index = pslot->ctlr_index;
530 
531 	index = hpc_readcmdtoindex(cmd, index);
532 
533 	if (index == HPC_ERROR) {
534 		rc = -EINVAL;
535 		err("%s - Exit Error:invalid index, rc[%d]\n", __func__, rc);
536 		return rc;
537 	}
538 
539 	ctlr_ptr = pslot->ctrl;
540 
541 	get_hpc_access();
542 
543 	//--------------------------------------------------------------------
544 	// map physical address to logical address
545 	//--------------------------------------------------------------------
546 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
547 		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
548 
549 	//--------------------------------------------------------------------
550 	// check controller status before reading
551 	//--------------------------------------------------------------------
552 	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
553 	if (!rc) {
554 		switch (cmd) {
555 		case READ_ALLSTAT:
556 			// update the slot structure
557 			pslot->ctrl->status = status;
558 			pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
559 			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
560 						       &status);
561 			if (!rc)
562 				pslot->ext_status = ctrl_read(ctlr_ptr, wpg_bbar, index + WPG_1ST_EXTSLOT_INDEX);
563 
564 			break;
565 
566 		case READ_SLOTSTATUS:
567 			// DO NOT update the slot structure
568 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
569 			break;
570 
571 		case READ_EXTSLOTSTATUS:
572 			// DO NOT update the slot structure
573 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
574 			break;
575 
576 		case READ_CTLRSTATUS:
577 			// DO NOT update the slot structure
578 			*pstatus = status;
579 			break;
580 
581 		case READ_BUSSTATUS:
582 			pslot->busstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
583 			break;
584 		case READ_REVLEVEL:
585 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
586 			break;
587 		case READ_HPCOPTIONS:
588 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
589 			break;
590 		case READ_SLOTLATCHLOWREG:
591 			// DO NOT update the slot structure
592 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
593 			break;
594 
595 			// Not used
596 		case READ_ALLSLOT:
597 			list_for_each_entry(pslot, &ibmphp_slot_head,
598 					    ibm_slot_list) {
599 				index = pslot->ctlr_index;
600 				rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr,
601 								wpg_bbar, &status);
602 				if (!rc) {
603 					pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
604 					rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT,
605 									ctlr_ptr, wpg_bbar, &status);
606 					if (!rc)
607 						pslot->ext_status =
608 						    ctrl_read(ctlr_ptr, wpg_bbar,
609 								index + WPG_1ST_EXTSLOT_INDEX);
610 				} else {
611 					err("%s - Error ctrl_read failed\n", __func__);
612 					rc = -EINVAL;
613 					break;
614 				}
615 			}
616 			break;
617 		default:
618 			rc = -EINVAL;
619 			break;
620 		}
621 	}
622 	//--------------------------------------------------------------------
623 	// cleanup
624 	//--------------------------------------------------------------------
625 
626 	// remove physical to logical address mapping
627 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
628 		iounmap(wpg_bbar);
629 
630 	free_hpc_access();
631 
632 	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
633 	return rc;
634 }
635 
636 /*----------------------------------------------------------------------
637 * Name:    ibmphp_hpc_writeslot()
638 *
639 * Action: issue a WRITE command to HPC
640 *---------------------------------------------------------------------*/
641 int ibmphp_hpc_writeslot(struct slot *pslot, u8 cmd)
642 {
643 	void __iomem *wpg_bbar = NULL;
644 	struct controller *ctlr_ptr;
645 	u8 index, status;
646 	int busindex;
647 	u8 done;
648 	int rc = 0;
649 	int timeout;
650 
651 	debug_polling("%s - Entry pslot[%p] cmd[%x]\n", __func__, pslot, cmd);
652 	if (pslot == NULL) {
653 		rc = -EINVAL;
654 		err("%s - Error Exit rc[%d]\n", __func__, rc);
655 		return rc;
656 	}
657 
658 	if ((cmd == HPC_BUS_33CONVMODE) || (cmd == HPC_BUS_66CONVMODE) ||
659 		(cmd == HPC_BUS_66PCIXMODE) || (cmd == HPC_BUS_100PCIXMODE) ||
660 		(cmd == HPC_BUS_133PCIXMODE)) {
661 		busindex = ibmphp_get_bus_index(pslot->bus);
662 		if (busindex < 0) {
663 			rc = -EINVAL;
664 			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
665 			return rc;
666 		} else
667 			index = (u8) busindex;
668 	} else
669 		index = pslot->ctlr_index;
670 
671 	index = hpc_writecmdtoindex(cmd, index);
672 
673 	if (index == HPC_ERROR) {
674 		rc = -EINVAL;
675 		err("%s - Error Exit rc[%d]\n", __func__, rc);
676 		return rc;
677 	}
678 
679 	ctlr_ptr = pslot->ctrl;
680 
681 	get_hpc_access();
682 
683 	//--------------------------------------------------------------------
684 	// map physical address to logical address
685 	//--------------------------------------------------------------------
686 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4)) {
687 		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
688 
689 		debug("%s - ctlr id[%x] physical[%lx] logical[%lx] i2c[%x]\n", __func__,
690 		ctlr_ptr->ctlr_id, (ulong) (ctlr_ptr->u.wpeg_ctlr.wpegbbar), (ulong) wpg_bbar,
691 		ctlr_ptr->u.wpeg_ctlr.i2c_addr);
692 	}
693 	//--------------------------------------------------------------------
694 	// check controller status before writing
695 	//--------------------------------------------------------------------
696 	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
697 	if (!rc) {
698 
699 		ctrl_write(ctlr_ptr, wpg_bbar, index, cmd);
700 
701 		//--------------------------------------------------------------------
702 		// check controller is still not working on the command
703 		//--------------------------------------------------------------------
704 		timeout = CMD_COMPLETE_TOUT_SEC;
705 		done = 0;
706 		while (!done) {
707 			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
708 							&status);
709 			if (!rc) {
710 				if (NEEDTOCHECK_CMDSTATUS(cmd)) {
711 					if (CTLR_FINISHED(status) == HPC_CTLR_FINISHED_YES)
712 						done = 1;
713 				} else
714 					done = 1;
715 			}
716 			if (!done) {
717 				msleep(1000);
718 				if (timeout < 1) {
719 					done = 1;
720 					err("%s - Error command complete timeout\n", __func__);
721 					rc = -EFAULT;
722 				} else
723 					timeout--;
724 			}
725 		}
726 		ctlr_ptr->status = status;
727 	}
728 	// cleanup
729 
730 	// remove physical to logical address mapping
731 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
732 		iounmap(wpg_bbar);
733 	free_hpc_access();
734 
735 	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
736 	return rc;
737 }
738 
739 /*----------------------------------------------------------------------
740 * Name:    get_hpc_access()
741 *
742 * Action: make sure only one process can access HPC at one time
743 *---------------------------------------------------------------------*/
744 static void get_hpc_access(void)
745 {
746 	mutex_lock(&sem_hpcaccess);
747 }
748 
749 /*----------------------------------------------------------------------
750 * Name:    free_hpc_access()
751 *---------------------------------------------------------------------*/
752 void free_hpc_access(void)
753 {
754 	mutex_unlock(&sem_hpcaccess);
755 }
756 
757 /*----------------------------------------------------------------------
758 * Name:    ibmphp_lock_operations()
759 *
760 * Action: make sure only one process can change the data structure
761 *---------------------------------------------------------------------*/
762 void ibmphp_lock_operations(void)
763 {
764 	mutex_lock(&operations_mutex);
765 	to_debug = 1;
766 }
767 
768 /*----------------------------------------------------------------------
769 * Name:    ibmphp_unlock_operations()
770 *---------------------------------------------------------------------*/
771 void ibmphp_unlock_operations(void)
772 {
773 	debug("%s - Entry\n", __func__);
774 	mutex_unlock(&operations_mutex);
775 	to_debug = 0;
776 	debug("%s - Exit\n", __func__);
777 }
778 
779 /*----------------------------------------------------------------------
780 * Name:    poll_hpc()
781 *---------------------------------------------------------------------*/
782 #define POLL_LATCH_REGISTER	0
783 #define POLL_SLOTS		1
784 #define POLL_SLEEP		2
785 static int poll_hpc(void *data)
786 {
787 	struct slot myslot;
788 	struct slot *pslot = NULL;
789 	int rc;
790 	int poll_state = POLL_LATCH_REGISTER;
791 	u8 oldlatchlow = 0x00;
792 	u8 curlatchlow = 0x00;
793 	int poll_count = 0;
794 	u8 ctrl_count = 0x00;
795 
796 	debug("%s - Entry\n", __func__);
797 
798 	while (!kthread_should_stop()) {
799 		/* try to get the lock to do some kind of hardware access */
800 		mutex_lock(&operations_mutex);
801 
802 		switch (poll_state) {
803 		case POLL_LATCH_REGISTER:
804 			oldlatchlow = curlatchlow;
805 			ctrl_count = 0x00;
806 			list_for_each_entry(pslot, &ibmphp_slot_head,
807 					    ibm_slot_list) {
808 				if (ctrl_count >= ibmphp_get_total_controllers())
809 					break;
810 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
811 					ctrl_count++;
812 					if (READ_SLOT_LATCH(pslot->ctrl)) {
813 						rc = ibmphp_hpc_readslot(pslot,
814 									  READ_SLOTLATCHLOWREG,
815 									  &curlatchlow);
816 						if (oldlatchlow != curlatchlow)
817 							process_changeinlatch(oldlatchlow,
818 									       curlatchlow,
819 									       pslot->ctrl);
820 					}
821 				}
822 			}
823 			++poll_count;
824 			poll_state = POLL_SLEEP;
825 			break;
826 		case POLL_SLOTS:
827 			list_for_each_entry(pslot, &ibmphp_slot_head,
828 					    ibm_slot_list) {
829 				// make a copy of the old status
830 				memcpy((void *) &myslot, (void *) pslot,
831 					sizeof(struct slot));
832 				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
833 				if ((myslot.status != pslot->status)
834 				    || (myslot.ext_status != pslot->ext_status))
835 					process_changeinstatus(pslot, &myslot);
836 			}
837 			ctrl_count = 0x00;
838 			list_for_each_entry(pslot, &ibmphp_slot_head,
839 					    ibm_slot_list) {
840 				if (ctrl_count >= ibmphp_get_total_controllers())
841 					break;
842 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
843 					ctrl_count++;
844 					if (READ_SLOT_LATCH(pslot->ctrl))
845 						rc = ibmphp_hpc_readslot(pslot,
846 									  READ_SLOTLATCHLOWREG,
847 									  &curlatchlow);
848 				}
849 			}
850 			++poll_count;
851 			poll_state = POLL_SLEEP;
852 			break;
853 		case POLL_SLEEP:
854 			/* don't sleep with a lock on the hardware */
855 			mutex_unlock(&operations_mutex);
856 			msleep(POLL_INTERVAL_SEC * 1000);
857 
858 			if (kthread_should_stop())
859 				goto out_sleep;
860 
861 			mutex_lock(&operations_mutex);
862 
863 			if (poll_count >= POLL_LATCH_CNT) {
864 				poll_count = 0;
865 				poll_state = POLL_SLOTS;
866 			} else
867 				poll_state = POLL_LATCH_REGISTER;
868 			break;
869 		}
870 		/* give up the hardware semaphore */
871 		mutex_unlock(&operations_mutex);
872 		/* sleep for a short time just for good measure */
873 out_sleep:
874 		msleep(100);
875 	}
876 	complete(&exit_complete);
877 	debug("%s - Exit\n", __func__);
878 	return 0;
879 }
880 
881 
882 /*----------------------------------------------------------------------
883 * Name:    process_changeinstatus
884 *
885 * Action:  compare old and new slot status, process the change in status
886 *
887 * Input:   pointer to slot struct, old slot struct
888 *
889 * Return   0 or error codes
890 * Value:
891 *
892 * Side
893 * Effects: None.
894 *
895 * Notes:
896 *---------------------------------------------------------------------*/
897 static int process_changeinstatus(struct slot *pslot, struct slot *poldslot)
898 {
899 	u8 status;
900 	int rc = 0;
901 	u8 disable = 0;
902 	u8 update = 0;
903 
904 	debug("process_changeinstatus - Entry pslot[%p], poldslot[%p]\n", pslot, poldslot);
905 
906 	// bit 0 - HPC_SLOT_POWER
907 	if ((pslot->status & 0x01) != (poldslot->status & 0x01))
908 		update = 1;
909 
910 	// bit 1 - HPC_SLOT_CONNECT
911 	// ignore
912 
913 	// bit 2 - HPC_SLOT_ATTN
914 	if ((pslot->status & 0x04) != (poldslot->status & 0x04))
915 		update = 1;
916 
917 	// bit 3 - HPC_SLOT_PRSNT2
918 	// bit 4 - HPC_SLOT_PRSNT1
919 	if (((pslot->status & 0x08) != (poldslot->status & 0x08))
920 		|| ((pslot->status & 0x10) != (poldslot->status & 0x10)))
921 		update = 1;
922 
923 	// bit 5 - HPC_SLOT_PWRGD
924 	if ((pslot->status & 0x20) != (poldslot->status & 0x20))
925 		// OFF -> ON: ignore, ON -> OFF: disable slot
926 		if ((poldslot->status & 0x20) && (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status)))
927 			disable = 1;
928 
929 	// bit 6 - HPC_SLOT_BUS_SPEED
930 	// ignore
931 
932 	// bit 7 - HPC_SLOT_LATCH
933 	if ((pslot->status & 0x80) != (poldslot->status & 0x80)) {
934 		update = 1;
935 		// OPEN -> CLOSE
936 		if (pslot->status & 0x80) {
937 			if (SLOT_PWRGD(pslot->status)) {
938 				// power goes on and off after closing latch
939 				// check again to make sure power is still ON
940 				msleep(1000);
941 				rc = ibmphp_hpc_readslot(pslot, READ_SLOTSTATUS, &status);
942 				if (SLOT_PWRGD(status))
943 					update = 1;
944 				else	// overwrite power in pslot to OFF
945 					pslot->status &= ~HPC_SLOT_POWER;
946 			}
947 		}
948 		// CLOSE -> OPEN
949 		else if ((SLOT_PWRGD(poldslot->status) == HPC_SLOT_PWRGD_GOOD)
950 			&& (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status))) {
951 			disable = 1;
952 		}
953 		// else - ignore
954 	}
955 	// bit 4 - HPC_SLOT_BLINK_ATTN
956 	if ((pslot->ext_status & 0x08) != (poldslot->ext_status & 0x08))
957 		update = 1;
958 
959 	if (disable) {
960 		debug("process_changeinstatus - disable slot\n");
961 		pslot->flag = 0;
962 		rc = ibmphp_do_disable_slot(pslot);
963 	}
964 
965 	if (update || disable)
966 		ibmphp_update_slot_info(pslot);
967 
968 	debug("%s - Exit rc[%d] disable[%x] update[%x]\n", __func__, rc, disable, update);
969 
970 	return rc;
971 }
972 
973 /*----------------------------------------------------------------------
974 * Name:    process_changeinlatch
975 *
976 * Action:  compare old and new latch reg status, process the change
977 *
978 * Input:   old and current latch register status
979 *
980 * Return   0 or error codes
981 * Value:
982 *---------------------------------------------------------------------*/
983 static int process_changeinlatch(u8 old, u8 new, struct controller *ctrl)
984 {
985 	struct slot myslot, *pslot;
986 	u8 i;
987 	u8 mask;
988 	int rc = 0;
989 
990 	debug("%s - Entry old[%x], new[%x]\n", __func__, old, new);
991 	// bit 0 reserved, 0 is LSB, check bit 1-6 for 6 slots
992 
993 	for (i = ctrl->starting_slot_num; i <= ctrl->ending_slot_num; i++) {
994 		mask = 0x01 << i;
995 		if ((mask & old) != (mask & new)) {
996 			pslot = ibmphp_get_slot_from_physical_num(i);
997 			if (pslot) {
998 				memcpy((void *) &myslot, (void *) pslot, sizeof(struct slot));
999 				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
1000 				debug("%s - call process_changeinstatus for slot[%d]\n", __func__, i);
1001 				process_changeinstatus(pslot, &myslot);
1002 			} else {
1003 				rc = -EINVAL;
1004 				err("%s - Error bad pointer for slot[%d]\n", __func__, i);
1005 			}
1006 		}
1007 	}
1008 	debug("%s - Exit rc[%d]\n", __func__, rc);
1009 	return rc;
1010 }
1011 
1012 /*----------------------------------------------------------------------
1013 * Name:    ibmphp_hpc_start_poll_thread
1014 *
1015 * Action:  start polling thread
1016 *---------------------------------------------------------------------*/
1017 int __init ibmphp_hpc_start_poll_thread(void)
1018 {
1019 	debug("%s - Entry\n", __func__);
1020 
1021 	ibmphp_poll_thread = kthread_run(poll_hpc, NULL, "hpc_poll");
1022 	if (IS_ERR(ibmphp_poll_thread)) {
1023 		err("%s - Error, thread not started\n", __func__);
1024 		return PTR_ERR(ibmphp_poll_thread);
1025 	}
1026 	return 0;
1027 }
1028 
1029 /*----------------------------------------------------------------------
1030 * Name:    ibmphp_hpc_stop_poll_thread
1031 *
1032 * Action:  stop polling thread and cleanup
1033 *---------------------------------------------------------------------*/
1034 void __exit ibmphp_hpc_stop_poll_thread(void)
1035 {
1036 	debug("%s - Entry\n", __func__);
1037 
1038 	kthread_stop(ibmphp_poll_thread);
1039 	debug("before locking operations\n");
1040 	ibmphp_lock_operations();
1041 	debug("after locking operations\n");
1042 
1043 	// wait for poll thread to exit
1044 	debug("before exit_complete down\n");
1045 	wait_for_completion(&exit_complete);
1046 	debug("after exit_completion down\n");
1047 
1048 	// cleanup
1049 	debug("before free_hpc_access\n");
1050 	free_hpc_access();
1051 	debug("after free_hpc_access\n");
1052 	ibmphp_unlock_operations();
1053 	debug("after unlock operations\n");
1054 
1055 	debug("%s - Exit\n", __func__);
1056 }
1057 
1058 /*----------------------------------------------------------------------
1059 * Name:    hpc_wait_ctlr_notworking
1060 *
1061 * Action:  wait until the controller is in a not working state
1062 *
1063 * Return   0, HPC_ERROR
1064 * Value:
1065 *---------------------------------------------------------------------*/
1066 static int hpc_wait_ctlr_notworking(int timeout, struct controller *ctlr_ptr, void __iomem *wpg_bbar,
1067 				    u8 *pstatus)
1068 {
1069 	int rc = 0;
1070 	u8 done = 0;
1071 
1072 	debug_polling("hpc_wait_ctlr_notworking - Entry timeout[%d]\n", timeout);
1073 
1074 	while (!done) {
1075 		*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, WPG_CTLR_INDEX);
1076 		if (*pstatus == HPC_ERROR) {
1077 			rc = HPC_ERROR;
1078 			done = 1;
1079 		}
1080 		if (CTLR_WORKING(*pstatus) == HPC_CTLR_WORKING_NO)
1081 			done = 1;
1082 		if (!done) {
1083 			msleep(1000);
1084 			if (timeout < 1) {
1085 				done = 1;
1086 				err("HPCreadslot - Error ctlr timeout\n");
1087 				rc = HPC_ERROR;
1088 			} else
1089 				timeout--;
1090 		}
1091 	}
1092 	debug_polling("hpc_wait_ctlr_notworking - Exit rc[%x] status[%x]\n", rc, *pstatus);
1093 	return rc;
1094 }
1095