xref: /openbmc/linux/drivers/pci/hotplug/ibmphp_hpc.c (revision 930beb5a)
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 	struct list_head *pslotlist;
541 	u8 index, status;
542 	int rc = 0;
543 	int busindex;
544 
545 	debug_polling ("%s - Entry pslot[%p] cmd[%x] pstatus[%p]\n", __func__, pslot, cmd, pstatus);
546 
547 	if ((pslot == NULL)
548 	    || ((pstatus == NULL) && (cmd != READ_ALLSTAT) && (cmd != READ_BUSSTATUS))) {
549 		rc = -EINVAL;
550 		err ("%s - Error invalid pointer, rc[%d]\n", __func__, rc);
551 		return rc;
552 	}
553 
554 	if (cmd == READ_BUSSTATUS) {
555 		busindex = ibmphp_get_bus_index (pslot->bus);
556 		if (busindex < 0) {
557 			rc = -EINVAL;
558 			err ("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
559 			return rc;
560 		} else
561 			index = (u8) busindex;
562 	} else
563 		index = pslot->ctlr_index;
564 
565 	index = hpc_readcmdtoindex (cmd, index);
566 
567 	if (index == HPC_ERROR) {
568 		rc = -EINVAL;
569 		err ("%s - Exit Error:invalid index, rc[%d]\n", __func__, rc);
570 		return rc;
571 	}
572 
573 	ctlr_ptr = pslot->ctrl;
574 
575 	get_hpc_access ();
576 
577 	//--------------------------------------------------------------------
578 	// map physical address to logical address
579 	//--------------------------------------------------------------------
580 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
581 		wpg_bbar = ioremap (ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
582 
583 	//--------------------------------------------------------------------
584 	// check controller status before reading
585 	//--------------------------------------------------------------------
586 	rc = hpc_wait_ctlr_notworking (HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
587 	if (!rc) {
588 		switch (cmd) {
589 		case READ_ALLSTAT:
590 			// update the slot structure
591 			pslot->ctrl->status = status;
592 			pslot->status = ctrl_read (ctlr_ptr, wpg_bbar, index);
593 			rc = hpc_wait_ctlr_notworking (HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
594 						       &status);
595 			if (!rc)
596 				pslot->ext_status = ctrl_read (ctlr_ptr, wpg_bbar, index + WPG_1ST_EXTSLOT_INDEX);
597 
598 			break;
599 
600 		case READ_SLOTSTATUS:
601 			// DO NOT update the slot structure
602 			*pstatus = ctrl_read (ctlr_ptr, wpg_bbar, index);
603 			break;
604 
605 		case READ_EXTSLOTSTATUS:
606 			// DO NOT update the slot structure
607 			*pstatus = ctrl_read (ctlr_ptr, wpg_bbar, index);
608 			break;
609 
610 		case READ_CTLRSTATUS:
611 			// DO NOT update the slot structure
612 			*pstatus = status;
613 			break;
614 
615 		case READ_BUSSTATUS:
616 			pslot->busstatus = ctrl_read (ctlr_ptr, wpg_bbar, index);
617 			break;
618 		case READ_REVLEVEL:
619 			*pstatus = ctrl_read (ctlr_ptr, wpg_bbar, index);
620 			break;
621 		case READ_HPCOPTIONS:
622 			*pstatus = ctrl_read (ctlr_ptr, wpg_bbar, index);
623 			break;
624 		case READ_SLOTLATCHLOWREG:
625 			// DO NOT update the slot structure
626 			*pstatus = ctrl_read (ctlr_ptr, wpg_bbar, index);
627 			break;
628 
629 			// Not used
630 		case READ_ALLSLOT:
631 			list_for_each (pslotlist, &ibmphp_slot_head) {
632 				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
633 				index = pslot->ctlr_index;
634 				rc = hpc_wait_ctlr_notworking (HPC_CTLR_WORKING_TOUT, ctlr_ptr,
635 								wpg_bbar, &status);
636 				if (!rc) {
637 					pslot->status = ctrl_read (ctlr_ptr, wpg_bbar, index);
638 					rc = hpc_wait_ctlr_notworking (HPC_CTLR_WORKING_TOUT,
639 									ctlr_ptr, wpg_bbar, &status);
640 					if (!rc)
641 						pslot->ext_status =
642 						    ctrl_read (ctlr_ptr, wpg_bbar,
643 								index + WPG_1ST_EXTSLOT_INDEX);
644 				} else {
645 					err ("%s - Error ctrl_read failed\n", __func__);
646 					rc = -EINVAL;
647 					break;
648 				}
649 			}
650 			break;
651 		default:
652 			rc = -EINVAL;
653 			break;
654 		}
655 	}
656 	//--------------------------------------------------------------------
657 	// cleanup
658 	//--------------------------------------------------------------------
659 
660 	// remove physical to logical address mapping
661 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
662 		iounmap (wpg_bbar);
663 
664 	free_hpc_access ();
665 
666 	debug_polling ("%s - Exit rc[%d]\n", __func__, rc);
667 	return rc;
668 }
669 
670 /*----------------------------------------------------------------------
671 * Name:    ibmphp_hpc_writeslot()
672 *
673 * Action: issue a WRITE command to HPC
674 *---------------------------------------------------------------------*/
675 int ibmphp_hpc_writeslot (struct slot * pslot, u8 cmd)
676 {
677 	void __iomem *wpg_bbar = NULL;
678 	struct controller *ctlr_ptr;
679 	u8 index, status;
680 	int busindex;
681 	u8 done;
682 	int rc = 0;
683 	int timeout;
684 
685 	debug_polling ("%s - Entry pslot[%p] cmd[%x]\n", __func__, pslot, cmd);
686 	if (pslot == NULL) {
687 		rc = -EINVAL;
688 		err ("%s - Error Exit rc[%d]\n", __func__, rc);
689 		return rc;
690 	}
691 
692 	if ((cmd == HPC_BUS_33CONVMODE) || (cmd == HPC_BUS_66CONVMODE) ||
693 		(cmd == HPC_BUS_66PCIXMODE) || (cmd == HPC_BUS_100PCIXMODE) ||
694 		(cmd == HPC_BUS_133PCIXMODE)) {
695 		busindex = ibmphp_get_bus_index (pslot->bus);
696 		if (busindex < 0) {
697 			rc = -EINVAL;
698 			err ("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
699 			return rc;
700 		} else
701 			index = (u8) busindex;
702 	} else
703 		index = pslot->ctlr_index;
704 
705 	index = hpc_writecmdtoindex (cmd, index);
706 
707 	if (index == HPC_ERROR) {
708 		rc = -EINVAL;
709 		err ("%s - Error Exit rc[%d]\n", __func__, rc);
710 		return rc;
711 	}
712 
713 	ctlr_ptr = pslot->ctrl;
714 
715 	get_hpc_access ();
716 
717 	//--------------------------------------------------------------------
718 	// map physical address to logical address
719 	//--------------------------------------------------------------------
720 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4)) {
721 		wpg_bbar = ioremap (ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
722 
723 		debug ("%s - ctlr id[%x] physical[%lx] logical[%lx] i2c[%x]\n", __func__,
724 		ctlr_ptr->ctlr_id, (ulong) (ctlr_ptr->u.wpeg_ctlr.wpegbbar), (ulong) wpg_bbar,
725 		ctlr_ptr->u.wpeg_ctlr.i2c_addr);
726 	}
727 	//--------------------------------------------------------------------
728 	// check controller status before writing
729 	//--------------------------------------------------------------------
730 	rc = hpc_wait_ctlr_notworking (HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
731 	if (!rc) {
732 
733 		ctrl_write (ctlr_ptr, wpg_bbar, index, cmd);
734 
735 		//--------------------------------------------------------------------
736 		// check controller is still not working on the command
737 		//--------------------------------------------------------------------
738 		timeout = CMD_COMPLETE_TOUT_SEC;
739 		done = 0;
740 		while (!done) {
741 			rc = hpc_wait_ctlr_notworking (HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
742 							&status);
743 			if (!rc) {
744 				if (NEEDTOCHECK_CMDSTATUS (cmd)) {
745 					if (CTLR_FINISHED (status) == HPC_CTLR_FINISHED_YES)
746 						done = 1;
747 				} else
748 					done = 1;
749 			}
750 			if (!done) {
751 				msleep(1000);
752 				if (timeout < 1) {
753 					done = 1;
754 					err ("%s - Error command complete timeout\n", __func__);
755 					rc = -EFAULT;
756 				} else
757 					timeout--;
758 			}
759 		}
760 		ctlr_ptr->status = status;
761 	}
762 	// cleanup
763 
764 	// remove physical to logical address mapping
765 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
766 		iounmap (wpg_bbar);
767 	free_hpc_access ();
768 
769 	debug_polling ("%s - Exit rc[%d]\n", __func__, rc);
770 	return rc;
771 }
772 
773 /*----------------------------------------------------------------------
774 * Name:    get_hpc_access()
775 *
776 * Action: make sure only one process can access HPC at one time
777 *---------------------------------------------------------------------*/
778 static void get_hpc_access (void)
779 {
780 	mutex_lock(&sem_hpcaccess);
781 }
782 
783 /*----------------------------------------------------------------------
784 * Name:    free_hpc_access()
785 *---------------------------------------------------------------------*/
786 void free_hpc_access (void)
787 {
788 	mutex_unlock(&sem_hpcaccess);
789 }
790 
791 /*----------------------------------------------------------------------
792 * Name:    ibmphp_lock_operations()
793 *
794 * Action: make sure only one process can change the data structure
795 *---------------------------------------------------------------------*/
796 void ibmphp_lock_operations (void)
797 {
798 	down (&semOperations);
799 	to_debug = 1;
800 }
801 
802 /*----------------------------------------------------------------------
803 * Name:    ibmphp_unlock_operations()
804 *---------------------------------------------------------------------*/
805 void ibmphp_unlock_operations (void)
806 {
807 	debug ("%s - Entry\n", __func__);
808 	up (&semOperations);
809 	to_debug = 0;
810 	debug ("%s - Exit\n", __func__);
811 }
812 
813 /*----------------------------------------------------------------------
814 * Name:    poll_hpc()
815 *---------------------------------------------------------------------*/
816 #define POLL_LATCH_REGISTER	0
817 #define POLL_SLOTS		1
818 #define POLL_SLEEP		2
819 static int poll_hpc(void *data)
820 {
821 	struct slot myslot;
822 	struct slot *pslot = NULL;
823 	struct list_head *pslotlist;
824 	int rc;
825 	int poll_state = POLL_LATCH_REGISTER;
826 	u8 oldlatchlow = 0x00;
827 	u8 curlatchlow = 0x00;
828 	int poll_count = 0;
829 	u8 ctrl_count = 0x00;
830 
831 	debug ("%s - Entry\n", __func__);
832 
833 	while (!kthread_should_stop()) {
834 		/* try to get the lock to do some kind of hardware access */
835 		down (&semOperations);
836 
837 		switch (poll_state) {
838 		case POLL_LATCH_REGISTER:
839 			oldlatchlow = curlatchlow;
840 			ctrl_count = 0x00;
841 			list_for_each (pslotlist, &ibmphp_slot_head) {
842 				if (ctrl_count >= ibmphp_get_total_controllers())
843 					break;
844 				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
845 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
846 					ctrl_count++;
847 					if (READ_SLOT_LATCH (pslot->ctrl)) {
848 						rc = ibmphp_hpc_readslot (pslot,
849 									  READ_SLOTLATCHLOWREG,
850 									  &curlatchlow);
851 						if (oldlatchlow != curlatchlow)
852 							process_changeinlatch (oldlatchlow,
853 									       curlatchlow,
854 									       pslot->ctrl);
855 					}
856 				}
857 			}
858 			++poll_count;
859 			poll_state = POLL_SLEEP;
860 			break;
861 		case POLL_SLOTS:
862 			list_for_each (pslotlist, &ibmphp_slot_head) {
863 				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
864 				// make a copy of the old status
865 				memcpy ((void *) &myslot, (void *) pslot,
866 					sizeof (struct slot));
867 				rc = ibmphp_hpc_readslot (pslot, READ_ALLSTAT, NULL);
868 				if ((myslot.status != pslot->status)
869 				    || (myslot.ext_status != pslot->ext_status))
870 					process_changeinstatus (pslot, &myslot);
871 			}
872 			ctrl_count = 0x00;
873 			list_for_each (pslotlist, &ibmphp_slot_head) {
874 				if (ctrl_count >= ibmphp_get_total_controllers())
875 					break;
876 				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
877 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
878 					ctrl_count++;
879 					if (READ_SLOT_LATCH (pslot->ctrl))
880 						rc = ibmphp_hpc_readslot (pslot,
881 									  READ_SLOTLATCHLOWREG,
882 									  &curlatchlow);
883 				}
884 			}
885 			++poll_count;
886 			poll_state = POLL_SLEEP;
887 			break;
888 		case POLL_SLEEP:
889 			/* don't sleep with a lock on the hardware */
890 			up (&semOperations);
891 			msleep(POLL_INTERVAL_SEC * 1000);
892 
893 			if (kthread_should_stop())
894 				goto out_sleep;
895 
896 			down (&semOperations);
897 
898 			if (poll_count >= POLL_LATCH_CNT) {
899 				poll_count = 0;
900 				poll_state = POLL_SLOTS;
901 			} else
902 				poll_state = POLL_LATCH_REGISTER;
903 			break;
904 		}
905 		/* give up the hardware semaphore */
906 		up (&semOperations);
907 		/* sleep for a short time just for good measure */
908 out_sleep:
909 		msleep(100);
910 	}
911 	up (&sem_exit);
912 	debug ("%s - Exit\n", __func__);
913 	return 0;
914 }
915 
916 
917 /*----------------------------------------------------------------------
918 * Name:    process_changeinstatus
919 *
920 * Action:  compare old and new slot status, process the change in status
921 *
922 * Input:   pointer to slot struct, old slot struct
923 *
924 * Return   0 or error codes
925 * Value:
926 *
927 * Side
928 * Effects: None.
929 *
930 * Notes:
931 *---------------------------------------------------------------------*/
932 static int process_changeinstatus (struct slot *pslot, struct slot *poldslot)
933 {
934 	u8 status;
935 	int rc = 0;
936 	u8 disable = 0;
937 	u8 update = 0;
938 
939 	debug ("process_changeinstatus - Entry pslot[%p], poldslot[%p]\n", pslot, poldslot);
940 
941 	// bit 0 - HPC_SLOT_POWER
942 	if ((pslot->status & 0x01) != (poldslot->status & 0x01))
943 		update = 1;
944 
945 	// bit 1 - HPC_SLOT_CONNECT
946 	// ignore
947 
948 	// bit 2 - HPC_SLOT_ATTN
949 	if ((pslot->status & 0x04) != (poldslot->status & 0x04))
950 		update = 1;
951 
952 	// bit 3 - HPC_SLOT_PRSNT2
953 	// bit 4 - HPC_SLOT_PRSNT1
954 	if (((pslot->status & 0x08) != (poldslot->status & 0x08))
955 		|| ((pslot->status & 0x10) != (poldslot->status & 0x10)))
956 		update = 1;
957 
958 	// bit 5 - HPC_SLOT_PWRGD
959 	if ((pslot->status & 0x20) != (poldslot->status & 0x20))
960 		// OFF -> ON: ignore, ON -> OFF: disable slot
961 		if ((poldslot->status & 0x20) && (SLOT_CONNECT (poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT (poldslot->status)))
962 			disable = 1;
963 
964 	// bit 6 - HPC_SLOT_BUS_SPEED
965 	// ignore
966 
967 	// bit 7 - HPC_SLOT_LATCH
968 	if ((pslot->status & 0x80) != (poldslot->status & 0x80)) {
969 		update = 1;
970 		// OPEN -> CLOSE
971 		if (pslot->status & 0x80) {
972 			if (SLOT_PWRGD (pslot->status)) {
973 				// power goes on and off after closing latch
974 				// check again to make sure power is still ON
975 				msleep(1000);
976 				rc = ibmphp_hpc_readslot (pslot, READ_SLOTSTATUS, &status);
977 				if (SLOT_PWRGD (status))
978 					update = 1;
979 				else	// overwrite power in pslot to OFF
980 					pslot->status &= ~HPC_SLOT_POWER;
981 			}
982 		}
983 		// CLOSE -> OPEN
984 		else if ((SLOT_PWRGD (poldslot->status) == HPC_SLOT_PWRGD_GOOD)
985 			&& (SLOT_CONNECT (poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT (poldslot->status))) {
986 			disable = 1;
987 		}
988 		// else - ignore
989 	}
990 	// bit 4 - HPC_SLOT_BLINK_ATTN
991 	if ((pslot->ext_status & 0x08) != (poldslot->ext_status & 0x08))
992 		update = 1;
993 
994 	if (disable) {
995 		debug ("process_changeinstatus - disable slot\n");
996 		pslot->flag = 0;
997 		rc = ibmphp_do_disable_slot (pslot);
998 	}
999 
1000 	if (update || disable) {
1001 		ibmphp_update_slot_info (pslot);
1002 	}
1003 
1004 	debug ("%s - Exit rc[%d] disable[%x] update[%x]\n", __func__, rc, disable, update);
1005 
1006 	return rc;
1007 }
1008 
1009 /*----------------------------------------------------------------------
1010 * Name:    process_changeinlatch
1011 *
1012 * Action:  compare old and new latch reg status, process the change
1013 *
1014 * Input:   old and current latch register status
1015 *
1016 * Return   0 or error codes
1017 * Value:
1018 *---------------------------------------------------------------------*/
1019 static int process_changeinlatch (u8 old, u8 new, struct controller *ctrl)
1020 {
1021 	struct slot myslot, *pslot;
1022 	u8 i;
1023 	u8 mask;
1024 	int rc = 0;
1025 
1026 	debug ("%s - Entry old[%x], new[%x]\n", __func__, old, new);
1027 	// bit 0 reserved, 0 is LSB, check bit 1-6 for 6 slots
1028 
1029 	for (i = ctrl->starting_slot_num; i <= ctrl->ending_slot_num; i++) {
1030 		mask = 0x01 << i;
1031 		if ((mask & old) != (mask & new)) {
1032 			pslot = ibmphp_get_slot_from_physical_num (i);
1033 			if (pslot) {
1034 				memcpy ((void *) &myslot, (void *) pslot, sizeof (struct slot));
1035 				rc = ibmphp_hpc_readslot (pslot, READ_ALLSTAT, NULL);
1036 				debug ("%s - call process_changeinstatus for slot[%d]\n", __func__, i);
1037 				process_changeinstatus (pslot, &myslot);
1038 			} else {
1039 				rc = -EINVAL;
1040 				err ("%s - Error bad pointer for slot[%d]\n", __func__, i);
1041 			}
1042 		}
1043 	}
1044 	debug ("%s - Exit rc[%d]\n", __func__, rc);
1045 	return rc;
1046 }
1047 
1048 /*----------------------------------------------------------------------
1049 * Name:    ibmphp_hpc_start_poll_thread
1050 *
1051 * Action:  start polling thread
1052 *---------------------------------------------------------------------*/
1053 int __init ibmphp_hpc_start_poll_thread (void)
1054 {
1055 	debug ("%s - Entry\n", __func__);
1056 
1057 	ibmphp_poll_thread = kthread_run(poll_hpc, NULL, "hpc_poll");
1058 	if (IS_ERR(ibmphp_poll_thread)) {
1059 		err ("%s - Error, thread not started\n", __func__);
1060 		return PTR_ERR(ibmphp_poll_thread);
1061 	}
1062 	return 0;
1063 }
1064 
1065 /*----------------------------------------------------------------------
1066 * Name:    ibmphp_hpc_stop_poll_thread
1067 *
1068 * Action:  stop polling thread and cleanup
1069 *---------------------------------------------------------------------*/
1070 void __exit ibmphp_hpc_stop_poll_thread (void)
1071 {
1072 	debug ("%s - Entry\n", __func__);
1073 
1074 	kthread_stop(ibmphp_poll_thread);
1075 	debug ("before locking operations \n");
1076 	ibmphp_lock_operations ();
1077 	debug ("after locking operations \n");
1078 
1079 	// wait for poll thread to exit
1080 	debug ("before sem_exit down \n");
1081 	down (&sem_exit);
1082 	debug ("after sem_exit down \n");
1083 
1084 	// cleanup
1085 	debug ("before free_hpc_access \n");
1086 	free_hpc_access ();
1087 	debug ("after free_hpc_access \n");
1088 	ibmphp_unlock_operations ();
1089 	debug ("after unlock operations \n");
1090 	up (&sem_exit);
1091 	debug ("after sem exit up\n");
1092 
1093 	debug ("%s - Exit\n", __func__);
1094 }
1095 
1096 /*----------------------------------------------------------------------
1097 * Name:    hpc_wait_ctlr_notworking
1098 *
1099 * Action:  wait until the controller is in a not working state
1100 *
1101 * Return   0, HPC_ERROR
1102 * Value:
1103 *---------------------------------------------------------------------*/
1104 static int hpc_wait_ctlr_notworking (int timeout, struct controller *ctlr_ptr, void __iomem *wpg_bbar,
1105 				    u8 * pstatus)
1106 {
1107 	int rc = 0;
1108 	u8 done = 0;
1109 
1110 	debug_polling ("hpc_wait_ctlr_notworking - Entry timeout[%d]\n", timeout);
1111 
1112 	while (!done) {
1113 		*pstatus = ctrl_read (ctlr_ptr, wpg_bbar, WPG_CTLR_INDEX);
1114 		if (*pstatus == HPC_ERROR) {
1115 			rc = HPC_ERROR;
1116 			done = 1;
1117 		}
1118 		if (CTLR_WORKING (*pstatus) == HPC_CTLR_WORKING_NO)
1119 			done = 1;
1120 		if (!done) {
1121 			msleep(1000);
1122 			if (timeout < 1) {
1123 				done = 1;
1124 				err ("HPCreadslot - Error ctlr timeout\n");
1125 				rc = HPC_ERROR;
1126 			} else
1127 				timeout--;
1128 		}
1129 	}
1130 	debug_polling ("hpc_wait_ctlr_notworking - Exit rc[%x] status[%x]\n", rc, *pstatus);
1131 	return rc;
1132 }
1133