xref: /openbmc/linux/drivers/pci/hotplug/ibmphp_hpc.c (revision f3539c12)
1 /*
2  * IBM Hot Plug Controller Driver
3  *
4  * Written By: Jyoti Shah, IBM Corporation
5  *
6  * Copyright (C) 2001-2003 IBM Corp.
7  *
8  * All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or (at
13  * your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18  * NON INFRINGEMENT.  See the GNU General Public License for more
19  * details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24  *
25  * Send feedback to <gregkh@us.ibm.com>
26  *                  <jshah@us.ibm.com>
27  *
28  */
29 
30 #include <linux/wait.h>
31 #include <linux/time.h>
32 #include <linux/delay.h>
33 #include <linux/module.h>
34 #include <linux/pci.h>
35 #include <linux/init.h>
36 #include <linux/mutex.h>
37 #include <linux/sched.h>
38 #include <linux/semaphore.h>
39 #include <linux/kthread.h>
40 #include "ibmphp.h"
41 
42 static int to_debug = 0;
43 #define debug_polling(fmt, arg...)	do { if (to_debug) debug(fmt, arg); } while (0)
44 
45 //----------------------------------------------------------------------------
46 // timeout values
47 //----------------------------------------------------------------------------
48 #define CMD_COMPLETE_TOUT_SEC	60	// give HPC 60 sec to finish cmd
49 #define HPC_CTLR_WORKING_TOUT	60	// give HPC 60 sec to finish cmd
50 #define HPC_GETACCESS_TIMEOUT	60	// seconds
51 #define POLL_INTERVAL_SEC	2	// poll HPC every 2 seconds
52 #define POLL_LATCH_CNT		5	// poll latch 5 times, then poll slots
53 
54 //----------------------------------------------------------------------------
55 // Winnipeg Architected Register Offsets
56 //----------------------------------------------------------------------------
57 #define WPG_I2CMBUFL_OFFSET	0x08	// I2C Message Buffer Low
58 #define WPG_I2CMOSUP_OFFSET	0x10	// I2C Master Operation Setup Reg
59 #define WPG_I2CMCNTL_OFFSET	0x20	// I2C Master Control Register
60 #define WPG_I2CPARM_OFFSET	0x40	// I2C Parameter Register
61 #define WPG_I2CSTAT_OFFSET	0x70	// I2C Status Register
62 
63 //----------------------------------------------------------------------------
64 // Winnipeg Store Type commands (Add this commands to the register offset)
65 //----------------------------------------------------------------------------
66 #define WPG_I2C_AND		0x1000	// I2C AND operation
67 #define WPG_I2C_OR		0x2000	// I2C OR operation
68 
69 //----------------------------------------------------------------------------
70 // Command set for I2C Master Operation Setup Register
71 //----------------------------------------------------------------------------
72 #define WPG_READATADDR_MASK	0x00010000	// read,bytes,I2C shifted,index
73 #define WPG_WRITEATADDR_MASK	0x40010000	// write,bytes,I2C shifted,index
74 #define WPG_READDIRECT_MASK	0x10010000
75 #define WPG_WRITEDIRECT_MASK	0x60010000
76 
77 
78 //----------------------------------------------------------------------------
79 // bit masks for I2C Master Control Register
80 //----------------------------------------------------------------------------
81 #define WPG_I2CMCNTL_STARTOP_MASK	0x00000002	// Start the Operation
82 
83 //----------------------------------------------------------------------------
84 //
85 //----------------------------------------------------------------------------
86 #define WPG_I2C_IOREMAP_SIZE	0x2044	// size of linear address interval
87 
88 //----------------------------------------------------------------------------
89 // command index
90 //----------------------------------------------------------------------------
91 #define WPG_1ST_SLOT_INDEX	0x01	// index - 1st slot for ctlr
92 #define WPG_CTLR_INDEX		0x0F	// index - ctlr
93 #define WPG_1ST_EXTSLOT_INDEX	0x10	// index - 1st ext slot for ctlr
94 #define WPG_1ST_BUS_INDEX	0x1F	// index - 1st bus for ctlr
95 
96 //----------------------------------------------------------------------------
97 // macro utilities
98 //----------------------------------------------------------------------------
99 // if bits 20,22,25,26,27,29,30 are OFF return 1
100 #define HPC_I2CSTATUS_CHECK(s)	((u8)((s & 0x00000A76) ? 0 : 1))
101 
102 //----------------------------------------------------------------------------
103 // global variables
104 //----------------------------------------------------------------------------
105 static struct mutex sem_hpcaccess;	// lock access to HPC
106 static struct semaphore semOperations;	// lock all operations and
107 					// access to data structures
108 static struct semaphore sem_exit;	// make sure polling thread goes away
109 static struct task_struct *ibmphp_poll_thread;
110 //----------------------------------------------------------------------------
111 // local function prototypes
112 //----------------------------------------------------------------------------
113 static u8 i2c_ctrl_read(struct controller *, void __iomem *, u8);
114 static u8 i2c_ctrl_write(struct controller *, void __iomem *, u8, u8);
115 static u8 hpc_writecmdtoindex(u8, u8);
116 static u8 hpc_readcmdtoindex(u8, u8);
117 static void get_hpc_access(void);
118 static void free_hpc_access(void);
119 static int poll_hpc(void *data);
120 static int process_changeinstatus(struct slot *, struct slot *);
121 static int process_changeinlatch(u8, u8, struct controller *);
122 static int hpc_wait_ctlr_notworking(int, struct controller *, void __iomem *, u8 *);
123 //----------------------------------------------------------------------------
124 
125 
126 /*----------------------------------------------------------------------
127 * Name:    ibmphp_hpc_initvars
128 *
129 * Action:  initialize semaphores and variables
130 *---------------------------------------------------------------------*/
131 void __init ibmphp_hpc_initvars(void)
132 {
133 	debug("%s - Entry\n", __func__);
134 
135 	mutex_init(&sem_hpcaccess);
136 	sema_init(&semOperations, 1);
137 	sema_init(&sem_exit, 0);
138 	to_debug = 0;
139 
140 	debug("%s - Exit\n", __func__);
141 }
142 
143 /*----------------------------------------------------------------------
144 * Name:    i2c_ctrl_read
145 *
146 * Action:  read from HPC over I2C
147 *
148 *---------------------------------------------------------------------*/
149 static u8 i2c_ctrl_read(struct controller *ctlr_ptr, void __iomem *WPGBbar, u8 index)
150 {
151 	u8 status;
152 	int i;
153 	void __iomem *wpg_addr;	// base addr + offset
154 	unsigned long wpg_data;	// data to/from WPG LOHI format
155 	unsigned long ultemp;
156 	unsigned long data;	// actual data HILO format
157 
158 	debug_polling("%s - Entry WPGBbar[%p] index[%x] \n", __func__, WPGBbar, index);
159 
160 	//--------------------------------------------------------------------
161 	// READ - step 1
162 	// read at address, byte length, I2C address (shifted), index
163 	// or read direct, byte length, index
164 	if (ctlr_ptr->ctlr_type == 0x02) {
165 		data = WPG_READATADDR_MASK;
166 		// fill in I2C address
167 		ultemp = (unsigned long)ctlr_ptr->u.wpeg_ctlr.i2c_addr;
168 		ultemp = ultemp >> 1;
169 		data |= (ultemp << 8);
170 
171 		// fill in index
172 		data |= (unsigned long)index;
173 	} else if (ctlr_ptr->ctlr_type == 0x04) {
174 		data = WPG_READDIRECT_MASK;
175 
176 		// fill in index
177 		ultemp = (unsigned long)index;
178 		ultemp = ultemp << 8;
179 		data |= ultemp;
180 	} else {
181 		err("this controller type is not supported \n");
182 		return HPC_ERROR;
183 	}
184 
185 	wpg_data = swab32(data);	// swap data before writing
186 	wpg_addr = WPGBbar + WPG_I2CMOSUP_OFFSET;
187 	writel(wpg_data, wpg_addr);
188 
189 	//--------------------------------------------------------------------
190 	// READ - step 2 : clear the message buffer
191 	data = 0x00000000;
192 	wpg_data = swab32(data);
193 	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
194 	writel(wpg_data, wpg_addr);
195 
196 	//--------------------------------------------------------------------
197 	// READ - step 3 : issue start operation, I2C master control bit 30:ON
198 	//                 2020 : [20] OR operation at [20] offset 0x20
199 	data = WPG_I2CMCNTL_STARTOP_MASK;
200 	wpg_data = swab32(data);
201 	wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET + WPG_I2C_OR;
202 	writel(wpg_data, wpg_addr);
203 
204 	//--------------------------------------------------------------------
205 	// READ - step 4 : wait until start operation bit clears
206 	i = CMD_COMPLETE_TOUT_SEC;
207 	while (i) {
208 		msleep(10);
209 		wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET;
210 		wpg_data = readl(wpg_addr);
211 		data = swab32(wpg_data);
212 		if (!(data & WPG_I2CMCNTL_STARTOP_MASK))
213 			break;
214 		i--;
215 	}
216 	if (i == 0) {
217 		debug("%s - Error : WPG timeout\n", __func__);
218 		return HPC_ERROR;
219 	}
220 	//--------------------------------------------------------------------
221 	// READ - step 5 : read I2C status register
222 	i = CMD_COMPLETE_TOUT_SEC;
223 	while (i) {
224 		msleep(10);
225 		wpg_addr = WPGBbar + WPG_I2CSTAT_OFFSET;
226 		wpg_data = readl(wpg_addr);
227 		data = swab32(wpg_data);
228 		if (HPC_I2CSTATUS_CHECK(data))
229 			break;
230 		i--;
231 	}
232 	if (i == 0) {
233 		debug("ctrl_read - Exit Error:I2C timeout\n");
234 		return HPC_ERROR;
235 	}
236 
237 	//--------------------------------------------------------------------
238 	// READ - step 6 : get DATA
239 	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
240 	wpg_data = readl(wpg_addr);
241 	data = swab32(wpg_data);
242 
243 	status = (u8) data;
244 
245 	debug_polling("%s - Exit index[%x] status[%x]\n", __func__, index, status);
246 
247 	return (status);
248 }
249 
250 /*----------------------------------------------------------------------
251 * Name:    i2c_ctrl_write
252 *
253 * Action:  write to HPC over I2C
254 *
255 * Return   0 or error codes
256 *---------------------------------------------------------------------*/
257 static u8 i2c_ctrl_write(struct controller *ctlr_ptr, void __iomem *WPGBbar, u8 index, u8 cmd)
258 {
259 	u8 rc;
260 	void __iomem *wpg_addr;	// base addr + offset
261 	unsigned long wpg_data;	// data to/from WPG LOHI format
262 	unsigned long ultemp;
263 	unsigned long data;	// actual data HILO format
264 	int i;
265 
266 	debug_polling("%s - Entry WPGBbar[%p] index[%x] cmd[%x]\n", __func__, WPGBbar, index, cmd);
267 
268 	rc = 0;
269 	//--------------------------------------------------------------------
270 	// WRITE - step 1
271 	// write at address, byte length, I2C address (shifted), index
272 	// or write direct, byte length, index
273 	data = 0x00000000;
274 
275 	if (ctlr_ptr->ctlr_type == 0x02) {
276 		data = WPG_WRITEATADDR_MASK;
277 		// fill in I2C address
278 		ultemp = (unsigned long)ctlr_ptr->u.wpeg_ctlr.i2c_addr;
279 		ultemp = ultemp >> 1;
280 		data |= (ultemp << 8);
281 
282 		// fill in index
283 		data |= (unsigned long)index;
284 	} else if (ctlr_ptr->ctlr_type == 0x04) {
285 		data = WPG_WRITEDIRECT_MASK;
286 
287 		// fill in index
288 		ultemp = (unsigned long)index;
289 		ultemp = ultemp << 8;
290 		data |= ultemp;
291 	} else {
292 		err("this controller type is not supported \n");
293 		return HPC_ERROR;
294 	}
295 
296 	wpg_data = swab32(data);	// swap data before writing
297 	wpg_addr = WPGBbar + WPG_I2CMOSUP_OFFSET;
298 	writel(wpg_data, wpg_addr);
299 
300 	//--------------------------------------------------------------------
301 	// WRITE - step 2 : clear the message buffer
302 	data = 0x00000000 | (unsigned long)cmd;
303 	wpg_data = swab32(data);
304 	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
305 	writel(wpg_data, wpg_addr);
306 
307 	//--------------------------------------------------------------------
308 	// WRITE - step 3 : issue start operation,I2C master control bit 30:ON
309 	//                 2020 : [20] OR operation at [20] offset 0x20
310 	data = WPG_I2CMCNTL_STARTOP_MASK;
311 	wpg_data = swab32(data);
312 	wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET + WPG_I2C_OR;
313 	writel(wpg_data, wpg_addr);
314 
315 	//--------------------------------------------------------------------
316 	// WRITE - step 4 : wait until start operation bit clears
317 	i = CMD_COMPLETE_TOUT_SEC;
318 	while (i) {
319 		msleep(10);
320 		wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET;
321 		wpg_data = readl(wpg_addr);
322 		data = swab32(wpg_data);
323 		if (!(data & WPG_I2CMCNTL_STARTOP_MASK))
324 			break;
325 		i--;
326 	}
327 	if (i == 0) {
328 		debug("%s - Exit Error:WPG timeout\n", __func__);
329 		rc = HPC_ERROR;
330 	}
331 
332 	//--------------------------------------------------------------------
333 	// WRITE - step 5 : read I2C status register
334 	i = CMD_COMPLETE_TOUT_SEC;
335 	while (i) {
336 		msleep(10);
337 		wpg_addr = WPGBbar + WPG_I2CSTAT_OFFSET;
338 		wpg_data = readl(wpg_addr);
339 		data = swab32(wpg_data);
340 		if (HPC_I2CSTATUS_CHECK(data))
341 			break;
342 		i--;
343 	}
344 	if (i == 0) {
345 		debug("ctrl_read - Error : I2C timeout\n");
346 		rc = HPC_ERROR;
347 	}
348 
349 	debug_polling("%s Exit rc[%x]\n", __func__, rc);
350 	return (rc);
351 }
352 
353 //------------------------------------------------------------
354 //  Read from ISA type HPC
355 //------------------------------------------------------------
356 static u8 isa_ctrl_read(struct controller *ctlr_ptr, u8 offset)
357 {
358 	u16 start_address;
359 	u16 end_address;
360 	u8 data;
361 
362 	start_address = ctlr_ptr->u.isa_ctlr.io_start;
363 	end_address = ctlr_ptr->u.isa_ctlr.io_end;
364 	data = inb(start_address + offset);
365 	return data;
366 }
367 
368 //--------------------------------------------------------------
369 // Write to ISA type HPC
370 //--------------------------------------------------------------
371 static void isa_ctrl_write(struct controller *ctlr_ptr, u8 offset, u8 data)
372 {
373 	u16 start_address;
374 	u16 port_address;
375 
376 	start_address = ctlr_ptr->u.isa_ctlr.io_start;
377 	port_address = start_address + (u16) offset;
378 	outb(data, port_address);
379 }
380 
381 static u8 pci_ctrl_read(struct controller *ctrl, u8 offset)
382 {
383 	u8 data = 0x00;
384 	debug("inside pci_ctrl_read\n");
385 	if (ctrl->ctrl_dev)
386 		pci_read_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, &data);
387 	return data;
388 }
389 
390 static u8 pci_ctrl_write(struct controller *ctrl, u8 offset, u8 data)
391 {
392 	u8 rc = -ENODEV;
393 	debug("inside pci_ctrl_write\n");
394 	if (ctrl->ctrl_dev) {
395 		pci_write_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, data);
396 		rc = 0;
397 	}
398 	return rc;
399 }
400 
401 static u8 ctrl_read(struct controller *ctlr, void __iomem *base, u8 offset)
402 {
403 	u8 rc;
404 	switch (ctlr->ctlr_type) {
405 	case 0:
406 		rc = isa_ctrl_read(ctlr, offset);
407 		break;
408 	case 1:
409 		rc = pci_ctrl_read(ctlr, offset);
410 		break;
411 	case 2:
412 	case 4:
413 		rc = i2c_ctrl_read(ctlr, base, offset);
414 		break;
415 	default:
416 		return -ENODEV;
417 	}
418 	return rc;
419 }
420 
421 static u8 ctrl_write(struct controller *ctlr, void __iomem *base, u8 offset, u8 data)
422 {
423 	u8 rc = 0;
424 	switch (ctlr->ctlr_type) {
425 	case 0:
426 		isa_ctrl_write(ctlr, offset, data);
427 		break;
428 	case 1:
429 		rc = pci_ctrl_write(ctlr, offset, data);
430 		break;
431 	case 2:
432 	case 4:
433 		rc = i2c_ctrl_write(ctlr, base, offset, data);
434 		break;
435 	default:
436 		return -ENODEV;
437 	}
438 	return rc;
439 }
440 /*----------------------------------------------------------------------
441 * Name:    hpc_writecmdtoindex()
442 *
443 * Action:  convert a write command to proper index within a controller
444 *
445 * Return   index, HPC_ERROR
446 *---------------------------------------------------------------------*/
447 static u8 hpc_writecmdtoindex(u8 cmd, u8 index)
448 {
449 	u8 rc;
450 
451 	switch (cmd) {
452 	case HPC_CTLR_ENABLEIRQ:	// 0x00.N.15
453 	case HPC_CTLR_CLEARIRQ:	// 0x06.N.15
454 	case HPC_CTLR_RESET:	// 0x07.N.15
455 	case HPC_CTLR_IRQSTEER:	// 0x08.N.15
456 	case HPC_CTLR_DISABLEIRQ:	// 0x01.N.15
457 	case HPC_ALLSLOT_ON:	// 0x11.N.15
458 	case HPC_ALLSLOT_OFF:	// 0x12.N.15
459 		rc = 0x0F;
460 		break;
461 
462 	case HPC_SLOT_OFF:	// 0x02.Y.0-14
463 	case HPC_SLOT_ON:	// 0x03.Y.0-14
464 	case HPC_SLOT_ATTNOFF:	// 0x04.N.0-14
465 	case HPC_SLOT_ATTNON:	// 0x05.N.0-14
466 	case HPC_SLOT_BLINKLED:	// 0x13.N.0-14
467 		rc = index;
468 		break;
469 
470 	case HPC_BUS_33CONVMODE:
471 	case HPC_BUS_66CONVMODE:
472 	case HPC_BUS_66PCIXMODE:
473 	case HPC_BUS_100PCIXMODE:
474 	case HPC_BUS_133PCIXMODE:
475 		rc = index + WPG_1ST_BUS_INDEX - 1;
476 		break;
477 
478 	default:
479 		err("hpc_writecmdtoindex - Error invalid cmd[%x]\n", cmd);
480 		rc = HPC_ERROR;
481 	}
482 
483 	return rc;
484 }
485 
486 /*----------------------------------------------------------------------
487 * Name:    hpc_readcmdtoindex()
488 *
489 * Action:  convert a read command to proper index within a controller
490 *
491 * Return   index, HPC_ERROR
492 *---------------------------------------------------------------------*/
493 static u8 hpc_readcmdtoindex(u8 cmd, u8 index)
494 {
495 	u8 rc;
496 
497 	switch (cmd) {
498 	case READ_CTLRSTATUS:
499 		rc = 0x0F;
500 		break;
501 	case READ_SLOTSTATUS:
502 	case READ_ALLSTAT:
503 		rc = index;
504 		break;
505 	case READ_EXTSLOTSTATUS:
506 		rc = index + WPG_1ST_EXTSLOT_INDEX;
507 		break;
508 	case READ_BUSSTATUS:
509 		rc = index + WPG_1ST_BUS_INDEX - 1;
510 		break;
511 	case READ_SLOTLATCHLOWREG:
512 		rc = 0x28;
513 		break;
514 	case READ_REVLEVEL:
515 		rc = 0x25;
516 		break;
517 	case READ_HPCOPTIONS:
518 		rc = 0x27;
519 		break;
520 	default:
521 		rc = HPC_ERROR;
522 	}
523 	return rc;
524 }
525 
526 /*----------------------------------------------------------------------
527 * Name:    HPCreadslot()
528 *
529 * Action:  issue a READ command to HPC
530 *
531 * Input:   pslot   - cannot be NULL for READ_ALLSTAT
532 *          pstatus - can be NULL for READ_ALLSTAT
533 *
534 * Return   0 or error codes
535 *---------------------------------------------------------------------*/
536 int ibmphp_hpc_readslot(struct slot *pslot, u8 cmd, u8 *pstatus)
537 {
538 	void __iomem *wpg_bbar = NULL;
539 	struct controller *ctlr_ptr;
540 	u8 index, status;
541 	int rc = 0;
542 	int busindex;
543 
544 	debug_polling("%s - Entry pslot[%p] cmd[%x] pstatus[%p]\n", __func__, pslot, cmd, pstatus);
545 
546 	if ((pslot == NULL)
547 	    || ((pstatus == NULL) && (cmd != READ_ALLSTAT) && (cmd != READ_BUSSTATUS))) {
548 		rc = -EINVAL;
549 		err("%s - Error invalid pointer, rc[%d]\n", __func__, rc);
550 		return rc;
551 	}
552 
553 	if (cmd == READ_BUSSTATUS) {
554 		busindex = ibmphp_get_bus_index(pslot->bus);
555 		if (busindex < 0) {
556 			rc = -EINVAL;
557 			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
558 			return rc;
559 		} else
560 			index = (u8) busindex;
561 	} else
562 		index = pslot->ctlr_index;
563 
564 	index = hpc_readcmdtoindex(cmd, index);
565 
566 	if (index == HPC_ERROR) {
567 		rc = -EINVAL;
568 		err("%s - Exit Error:invalid index, rc[%d]\n", __func__, rc);
569 		return rc;
570 	}
571 
572 	ctlr_ptr = pslot->ctrl;
573 
574 	get_hpc_access();
575 
576 	//--------------------------------------------------------------------
577 	// map physical address to logical address
578 	//--------------------------------------------------------------------
579 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
580 		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
581 
582 	//--------------------------------------------------------------------
583 	// check controller status before reading
584 	//--------------------------------------------------------------------
585 	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
586 	if (!rc) {
587 		switch (cmd) {
588 		case READ_ALLSTAT:
589 			// update the slot structure
590 			pslot->ctrl->status = status;
591 			pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
592 			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
593 						       &status);
594 			if (!rc)
595 				pslot->ext_status = ctrl_read(ctlr_ptr, wpg_bbar, index + WPG_1ST_EXTSLOT_INDEX);
596 
597 			break;
598 
599 		case READ_SLOTSTATUS:
600 			// DO NOT update the slot structure
601 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
602 			break;
603 
604 		case READ_EXTSLOTSTATUS:
605 			// DO NOT update the slot structure
606 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
607 			break;
608 
609 		case READ_CTLRSTATUS:
610 			// DO NOT update the slot structure
611 			*pstatus = status;
612 			break;
613 
614 		case READ_BUSSTATUS:
615 			pslot->busstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
616 			break;
617 		case READ_REVLEVEL:
618 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
619 			break;
620 		case READ_HPCOPTIONS:
621 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
622 			break;
623 		case READ_SLOTLATCHLOWREG:
624 			// DO NOT update the slot structure
625 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
626 			break;
627 
628 			// Not used
629 		case READ_ALLSLOT:
630 			list_for_each_entry(pslot, &ibmphp_slot_head,
631 					    ibm_slot_list) {
632 				index = pslot->ctlr_index;
633 				rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr,
634 								wpg_bbar, &status);
635 				if (!rc) {
636 					pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
637 					rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT,
638 									ctlr_ptr, wpg_bbar, &status);
639 					if (!rc)
640 						pslot->ext_status =
641 						    ctrl_read(ctlr_ptr, wpg_bbar,
642 								index + WPG_1ST_EXTSLOT_INDEX);
643 				} else {
644 					err("%s - Error ctrl_read failed\n", __func__);
645 					rc = -EINVAL;
646 					break;
647 				}
648 			}
649 			break;
650 		default:
651 			rc = -EINVAL;
652 			break;
653 		}
654 	}
655 	//--------------------------------------------------------------------
656 	// cleanup
657 	//--------------------------------------------------------------------
658 
659 	// remove physical to logical address mapping
660 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
661 		iounmap(wpg_bbar);
662 
663 	free_hpc_access();
664 
665 	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
666 	return rc;
667 }
668 
669 /*----------------------------------------------------------------------
670 * Name:    ibmphp_hpc_writeslot()
671 *
672 * Action: issue a WRITE command to HPC
673 *---------------------------------------------------------------------*/
674 int ibmphp_hpc_writeslot(struct slot *pslot, u8 cmd)
675 {
676 	void __iomem *wpg_bbar = NULL;
677 	struct controller *ctlr_ptr;
678 	u8 index, status;
679 	int busindex;
680 	u8 done;
681 	int rc = 0;
682 	int timeout;
683 
684 	debug_polling("%s - Entry pslot[%p] cmd[%x]\n", __func__, pslot, cmd);
685 	if (pslot == NULL) {
686 		rc = -EINVAL;
687 		err("%s - Error Exit rc[%d]\n", __func__, rc);
688 		return rc;
689 	}
690 
691 	if ((cmd == HPC_BUS_33CONVMODE) || (cmd == HPC_BUS_66CONVMODE) ||
692 		(cmd == HPC_BUS_66PCIXMODE) || (cmd == HPC_BUS_100PCIXMODE) ||
693 		(cmd == HPC_BUS_133PCIXMODE)) {
694 		busindex = ibmphp_get_bus_index(pslot->bus);
695 		if (busindex < 0) {
696 			rc = -EINVAL;
697 			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
698 			return rc;
699 		} else
700 			index = (u8) busindex;
701 	} else
702 		index = pslot->ctlr_index;
703 
704 	index = hpc_writecmdtoindex(cmd, index);
705 
706 	if (index == HPC_ERROR) {
707 		rc = -EINVAL;
708 		err("%s - Error Exit rc[%d]\n", __func__, rc);
709 		return rc;
710 	}
711 
712 	ctlr_ptr = pslot->ctrl;
713 
714 	get_hpc_access();
715 
716 	//--------------------------------------------------------------------
717 	// map physical address to logical address
718 	//--------------------------------------------------------------------
719 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4)) {
720 		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
721 
722 		debug("%s - ctlr id[%x] physical[%lx] logical[%lx] i2c[%x]\n", __func__,
723 		ctlr_ptr->ctlr_id, (ulong) (ctlr_ptr->u.wpeg_ctlr.wpegbbar), (ulong) wpg_bbar,
724 		ctlr_ptr->u.wpeg_ctlr.i2c_addr);
725 	}
726 	//--------------------------------------------------------------------
727 	// check controller status before writing
728 	//--------------------------------------------------------------------
729 	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
730 	if (!rc) {
731 
732 		ctrl_write(ctlr_ptr, wpg_bbar, index, cmd);
733 
734 		//--------------------------------------------------------------------
735 		// check controller is still not working on the command
736 		//--------------------------------------------------------------------
737 		timeout = CMD_COMPLETE_TOUT_SEC;
738 		done = 0;
739 		while (!done) {
740 			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
741 							&status);
742 			if (!rc) {
743 				if (NEEDTOCHECK_CMDSTATUS(cmd)) {
744 					if (CTLR_FINISHED(status) == HPC_CTLR_FINISHED_YES)
745 						done = 1;
746 				} else
747 					done = 1;
748 			}
749 			if (!done) {
750 				msleep(1000);
751 				if (timeout < 1) {
752 					done = 1;
753 					err("%s - Error command complete timeout\n", __func__);
754 					rc = -EFAULT;
755 				} else
756 					timeout--;
757 			}
758 		}
759 		ctlr_ptr->status = status;
760 	}
761 	// cleanup
762 
763 	// remove physical to logical address mapping
764 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
765 		iounmap(wpg_bbar);
766 	free_hpc_access();
767 
768 	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
769 	return rc;
770 }
771 
772 /*----------------------------------------------------------------------
773 * Name:    get_hpc_access()
774 *
775 * Action: make sure only one process can access HPC at one time
776 *---------------------------------------------------------------------*/
777 static void get_hpc_access(void)
778 {
779 	mutex_lock(&sem_hpcaccess);
780 }
781 
782 /*----------------------------------------------------------------------
783 * Name:    free_hpc_access()
784 *---------------------------------------------------------------------*/
785 void free_hpc_access(void)
786 {
787 	mutex_unlock(&sem_hpcaccess);
788 }
789 
790 /*----------------------------------------------------------------------
791 * Name:    ibmphp_lock_operations()
792 *
793 * Action: make sure only one process can change the data structure
794 *---------------------------------------------------------------------*/
795 void ibmphp_lock_operations(void)
796 {
797 	down(&semOperations);
798 	to_debug = 1;
799 }
800 
801 /*----------------------------------------------------------------------
802 * Name:    ibmphp_unlock_operations()
803 *---------------------------------------------------------------------*/
804 void ibmphp_unlock_operations(void)
805 {
806 	debug("%s - Entry\n", __func__);
807 	up(&semOperations);
808 	to_debug = 0;
809 	debug("%s - Exit\n", __func__);
810 }
811 
812 /*----------------------------------------------------------------------
813 * Name:    poll_hpc()
814 *---------------------------------------------------------------------*/
815 #define POLL_LATCH_REGISTER	0
816 #define POLL_SLOTS		1
817 #define POLL_SLEEP		2
818 static int poll_hpc(void *data)
819 {
820 	struct slot myslot;
821 	struct slot *pslot = NULL;
822 	int rc;
823 	int poll_state = POLL_LATCH_REGISTER;
824 	u8 oldlatchlow = 0x00;
825 	u8 curlatchlow = 0x00;
826 	int poll_count = 0;
827 	u8 ctrl_count = 0x00;
828 
829 	debug("%s - Entry\n", __func__);
830 
831 	while (!kthread_should_stop()) {
832 		/* try to get the lock to do some kind of hardware access */
833 		down(&semOperations);
834 
835 		switch (poll_state) {
836 		case POLL_LATCH_REGISTER:
837 			oldlatchlow = curlatchlow;
838 			ctrl_count = 0x00;
839 			list_for_each_entry(pslot, &ibmphp_slot_head,
840 					    ibm_slot_list) {
841 				if (ctrl_count >= ibmphp_get_total_controllers())
842 					break;
843 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
844 					ctrl_count++;
845 					if (READ_SLOT_LATCH(pslot->ctrl)) {
846 						rc = ibmphp_hpc_readslot(pslot,
847 									  READ_SLOTLATCHLOWREG,
848 									  &curlatchlow);
849 						if (oldlatchlow != curlatchlow)
850 							process_changeinlatch(oldlatchlow,
851 									       curlatchlow,
852 									       pslot->ctrl);
853 					}
854 				}
855 			}
856 			++poll_count;
857 			poll_state = POLL_SLEEP;
858 			break;
859 		case POLL_SLOTS:
860 			list_for_each_entry(pslot, &ibmphp_slot_head,
861 					    ibm_slot_list) {
862 				// make a copy of the old status
863 				memcpy((void *) &myslot, (void *) pslot,
864 					sizeof(struct slot));
865 				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
866 				if ((myslot.status != pslot->status)
867 				    || (myslot.ext_status != pslot->ext_status))
868 					process_changeinstatus(pslot, &myslot);
869 			}
870 			ctrl_count = 0x00;
871 			list_for_each_entry(pslot, &ibmphp_slot_head,
872 					    ibm_slot_list) {
873 				if (ctrl_count >= ibmphp_get_total_controllers())
874 					break;
875 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
876 					ctrl_count++;
877 					if (READ_SLOT_LATCH(pslot->ctrl))
878 						rc = ibmphp_hpc_readslot(pslot,
879 									  READ_SLOTLATCHLOWREG,
880 									  &curlatchlow);
881 				}
882 			}
883 			++poll_count;
884 			poll_state = POLL_SLEEP;
885 			break;
886 		case POLL_SLEEP:
887 			/* don't sleep with a lock on the hardware */
888 			up(&semOperations);
889 			msleep(POLL_INTERVAL_SEC * 1000);
890 
891 			if (kthread_should_stop())
892 				goto out_sleep;
893 
894 			down(&semOperations);
895 
896 			if (poll_count >= POLL_LATCH_CNT) {
897 				poll_count = 0;
898 				poll_state = POLL_SLOTS;
899 			} else
900 				poll_state = POLL_LATCH_REGISTER;
901 			break;
902 		}
903 		/* give up the hardware semaphore */
904 		up(&semOperations);
905 		/* sleep for a short time just for good measure */
906 out_sleep:
907 		msleep(100);
908 	}
909 	up(&sem_exit);
910 	debug("%s - Exit\n", __func__);
911 	return 0;
912 }
913 
914 
915 /*----------------------------------------------------------------------
916 * Name:    process_changeinstatus
917 *
918 * Action:  compare old and new slot status, process the change in status
919 *
920 * Input:   pointer to slot struct, old slot struct
921 *
922 * Return   0 or error codes
923 * Value:
924 *
925 * Side
926 * Effects: None.
927 *
928 * Notes:
929 *---------------------------------------------------------------------*/
930 static int process_changeinstatus(struct slot *pslot, struct slot *poldslot)
931 {
932 	u8 status;
933 	int rc = 0;
934 	u8 disable = 0;
935 	u8 update = 0;
936 
937 	debug("process_changeinstatus - Entry pslot[%p], poldslot[%p]\n", pslot, poldslot);
938 
939 	// bit 0 - HPC_SLOT_POWER
940 	if ((pslot->status & 0x01) != (poldslot->status & 0x01))
941 		update = 1;
942 
943 	// bit 1 - HPC_SLOT_CONNECT
944 	// ignore
945 
946 	// bit 2 - HPC_SLOT_ATTN
947 	if ((pslot->status & 0x04) != (poldslot->status & 0x04))
948 		update = 1;
949 
950 	// bit 3 - HPC_SLOT_PRSNT2
951 	// bit 4 - HPC_SLOT_PRSNT1
952 	if (((pslot->status & 0x08) != (poldslot->status & 0x08))
953 		|| ((pslot->status & 0x10) != (poldslot->status & 0x10)))
954 		update = 1;
955 
956 	// bit 5 - HPC_SLOT_PWRGD
957 	if ((pslot->status & 0x20) != (poldslot->status & 0x20))
958 		// OFF -> ON: ignore, ON -> OFF: disable slot
959 		if ((poldslot->status & 0x20) && (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status)))
960 			disable = 1;
961 
962 	// bit 6 - HPC_SLOT_BUS_SPEED
963 	// ignore
964 
965 	// bit 7 - HPC_SLOT_LATCH
966 	if ((pslot->status & 0x80) != (poldslot->status & 0x80)) {
967 		update = 1;
968 		// OPEN -> CLOSE
969 		if (pslot->status & 0x80) {
970 			if (SLOT_PWRGD(pslot->status)) {
971 				// power goes on and off after closing latch
972 				// check again to make sure power is still ON
973 				msleep(1000);
974 				rc = ibmphp_hpc_readslot(pslot, READ_SLOTSTATUS, &status);
975 				if (SLOT_PWRGD(status))
976 					update = 1;
977 				else	// overwrite power in pslot to OFF
978 					pslot->status &= ~HPC_SLOT_POWER;
979 			}
980 		}
981 		// CLOSE -> OPEN
982 		else if ((SLOT_PWRGD(poldslot->status) == HPC_SLOT_PWRGD_GOOD)
983 			&& (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status))) {
984 			disable = 1;
985 		}
986 		// else - ignore
987 	}
988 	// bit 4 - HPC_SLOT_BLINK_ATTN
989 	if ((pslot->ext_status & 0x08) != (poldslot->ext_status & 0x08))
990 		update = 1;
991 
992 	if (disable) {
993 		debug("process_changeinstatus - disable slot\n");
994 		pslot->flag = 0;
995 		rc = ibmphp_do_disable_slot(pslot);
996 	}
997 
998 	if (update || disable)
999 		ibmphp_update_slot_info(pslot);
1000 
1001 	debug("%s - Exit rc[%d] disable[%x] update[%x]\n", __func__, rc, disable, update);
1002 
1003 	return rc;
1004 }
1005 
1006 /*----------------------------------------------------------------------
1007 * Name:    process_changeinlatch
1008 *
1009 * Action:  compare old and new latch reg status, process the change
1010 *
1011 * Input:   old and current latch register status
1012 *
1013 * Return   0 or error codes
1014 * Value:
1015 *---------------------------------------------------------------------*/
1016 static int process_changeinlatch(u8 old, u8 new, struct controller *ctrl)
1017 {
1018 	struct slot myslot, *pslot;
1019 	u8 i;
1020 	u8 mask;
1021 	int rc = 0;
1022 
1023 	debug("%s - Entry old[%x], new[%x]\n", __func__, old, new);
1024 	// bit 0 reserved, 0 is LSB, check bit 1-6 for 6 slots
1025 
1026 	for (i = ctrl->starting_slot_num; i <= ctrl->ending_slot_num; i++) {
1027 		mask = 0x01 << i;
1028 		if ((mask & old) != (mask & new)) {
1029 			pslot = ibmphp_get_slot_from_physical_num(i);
1030 			if (pslot) {
1031 				memcpy((void *) &myslot, (void *) pslot, sizeof(struct slot));
1032 				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
1033 				debug("%s - call process_changeinstatus for slot[%d]\n", __func__, i);
1034 				process_changeinstatus(pslot, &myslot);
1035 			} else {
1036 				rc = -EINVAL;
1037 				err("%s - Error bad pointer for slot[%d]\n", __func__, i);
1038 			}
1039 		}
1040 	}
1041 	debug("%s - Exit rc[%d]\n", __func__, rc);
1042 	return rc;
1043 }
1044 
1045 /*----------------------------------------------------------------------
1046 * Name:    ibmphp_hpc_start_poll_thread
1047 *
1048 * Action:  start polling thread
1049 *---------------------------------------------------------------------*/
1050 int __init ibmphp_hpc_start_poll_thread(void)
1051 {
1052 	debug("%s - Entry\n", __func__);
1053 
1054 	ibmphp_poll_thread = kthread_run(poll_hpc, NULL, "hpc_poll");
1055 	if (IS_ERR(ibmphp_poll_thread)) {
1056 		err("%s - Error, thread not started\n", __func__);
1057 		return PTR_ERR(ibmphp_poll_thread);
1058 	}
1059 	return 0;
1060 }
1061 
1062 /*----------------------------------------------------------------------
1063 * Name:    ibmphp_hpc_stop_poll_thread
1064 *
1065 * Action:  stop polling thread and cleanup
1066 *---------------------------------------------------------------------*/
1067 void __exit ibmphp_hpc_stop_poll_thread(void)
1068 {
1069 	debug("%s - Entry\n", __func__);
1070 
1071 	kthread_stop(ibmphp_poll_thread);
1072 	debug("before locking operations\n");
1073 	ibmphp_lock_operations();
1074 	debug("after locking operations\n");
1075 
1076 	// wait for poll thread to exit
1077 	debug("before sem_exit down\n");
1078 	down(&sem_exit);
1079 	debug("after sem_exit down\n");
1080 
1081 	// cleanup
1082 	debug("before free_hpc_access\n");
1083 	free_hpc_access();
1084 	debug("after free_hpc_access\n");
1085 	ibmphp_unlock_operations();
1086 	debug("after unlock operations\n");
1087 	up(&sem_exit);
1088 	debug("after sem exit up\n");
1089 
1090 	debug("%s - Exit\n", __func__);
1091 }
1092 
1093 /*----------------------------------------------------------------------
1094 * Name:    hpc_wait_ctlr_notworking
1095 *
1096 * Action:  wait until the controller is in a not working state
1097 *
1098 * Return   0, HPC_ERROR
1099 * Value:
1100 *---------------------------------------------------------------------*/
1101 static int hpc_wait_ctlr_notworking(int timeout, struct controller *ctlr_ptr, void __iomem *wpg_bbar,
1102 				    u8 *pstatus)
1103 {
1104 	int rc = 0;
1105 	u8 done = 0;
1106 
1107 	debug_polling("hpc_wait_ctlr_notworking - Entry timeout[%d]\n", timeout);
1108 
1109 	while (!done) {
1110 		*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, WPG_CTLR_INDEX);
1111 		if (*pstatus == HPC_ERROR) {
1112 			rc = HPC_ERROR;
1113 			done = 1;
1114 		}
1115 		if (CTLR_WORKING(*pstatus) == HPC_CTLR_WORKING_NO)
1116 			done = 1;
1117 		if (!done) {
1118 			msleep(1000);
1119 			if (timeout < 1) {
1120 				done = 1;
1121 				err("HPCreadslot - Error ctlr timeout\n");
1122 				rc = HPC_ERROR;
1123 			} else
1124 				timeout--;
1125 		}
1126 	}
1127 	debug_polling("hpc_wait_ctlr_notworking - Exit rc[%x] status[%x]\n", rc, *pstatus);
1128 	return rc;
1129 }
1130