xref: /openbmc/linux/drivers/pci/hotplug/ibmphp_hpc.c (revision 55fd7e02)
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 	u16 end_address;
329 	u8 data;
330 
331 	start_address = ctlr_ptr->u.isa_ctlr.io_start;
332 	end_address = ctlr_ptr->u.isa_ctlr.io_end;
333 	data = inb(start_address + offset);
334 	return data;
335 }
336 
337 //--------------------------------------------------------------
338 // Write to ISA type HPC
339 //--------------------------------------------------------------
340 static void isa_ctrl_write(struct controller *ctlr_ptr, u8 offset, u8 data)
341 {
342 	u16 start_address;
343 	u16 port_address;
344 
345 	start_address = ctlr_ptr->u.isa_ctlr.io_start;
346 	port_address = start_address + (u16) offset;
347 	outb(data, port_address);
348 }
349 
350 static u8 pci_ctrl_read(struct controller *ctrl, u8 offset)
351 {
352 	u8 data = 0x00;
353 	debug("inside pci_ctrl_read\n");
354 	if (ctrl->ctrl_dev)
355 		pci_read_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, &data);
356 	return data;
357 }
358 
359 static u8 pci_ctrl_write(struct controller *ctrl, u8 offset, u8 data)
360 {
361 	u8 rc = -ENODEV;
362 	debug("inside pci_ctrl_write\n");
363 	if (ctrl->ctrl_dev) {
364 		pci_write_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, data);
365 		rc = 0;
366 	}
367 	return rc;
368 }
369 
370 static u8 ctrl_read(struct controller *ctlr, void __iomem *base, u8 offset)
371 {
372 	u8 rc;
373 	switch (ctlr->ctlr_type) {
374 	case 0:
375 		rc = isa_ctrl_read(ctlr, offset);
376 		break;
377 	case 1:
378 		rc = pci_ctrl_read(ctlr, offset);
379 		break;
380 	case 2:
381 	case 4:
382 		rc = i2c_ctrl_read(ctlr, base, offset);
383 		break;
384 	default:
385 		return -ENODEV;
386 	}
387 	return rc;
388 }
389 
390 static u8 ctrl_write(struct controller *ctlr, void __iomem *base, u8 offset, u8 data)
391 {
392 	u8 rc = 0;
393 	switch (ctlr->ctlr_type) {
394 	case 0:
395 		isa_ctrl_write(ctlr, offset, data);
396 		break;
397 	case 1:
398 		rc = pci_ctrl_write(ctlr, offset, data);
399 		break;
400 	case 2:
401 	case 4:
402 		rc = i2c_ctrl_write(ctlr, base, offset, data);
403 		break;
404 	default:
405 		return -ENODEV;
406 	}
407 	return rc;
408 }
409 /*----------------------------------------------------------------------
410 * Name:    hpc_writecmdtoindex()
411 *
412 * Action:  convert a write command to proper index within a controller
413 *
414 * Return   index, HPC_ERROR
415 *---------------------------------------------------------------------*/
416 static u8 hpc_writecmdtoindex(u8 cmd, u8 index)
417 {
418 	u8 rc;
419 
420 	switch (cmd) {
421 	case HPC_CTLR_ENABLEIRQ:	// 0x00.N.15
422 	case HPC_CTLR_CLEARIRQ:	// 0x06.N.15
423 	case HPC_CTLR_RESET:	// 0x07.N.15
424 	case HPC_CTLR_IRQSTEER:	// 0x08.N.15
425 	case HPC_CTLR_DISABLEIRQ:	// 0x01.N.15
426 	case HPC_ALLSLOT_ON:	// 0x11.N.15
427 	case HPC_ALLSLOT_OFF:	// 0x12.N.15
428 		rc = 0x0F;
429 		break;
430 
431 	case HPC_SLOT_OFF:	// 0x02.Y.0-14
432 	case HPC_SLOT_ON:	// 0x03.Y.0-14
433 	case HPC_SLOT_ATTNOFF:	// 0x04.N.0-14
434 	case HPC_SLOT_ATTNON:	// 0x05.N.0-14
435 	case HPC_SLOT_BLINKLED:	// 0x13.N.0-14
436 		rc = index;
437 		break;
438 
439 	case HPC_BUS_33CONVMODE:
440 	case HPC_BUS_66CONVMODE:
441 	case HPC_BUS_66PCIXMODE:
442 	case HPC_BUS_100PCIXMODE:
443 	case HPC_BUS_133PCIXMODE:
444 		rc = index + WPG_1ST_BUS_INDEX - 1;
445 		break;
446 
447 	default:
448 		err("hpc_writecmdtoindex - Error invalid cmd[%x]\n", cmd);
449 		rc = HPC_ERROR;
450 	}
451 
452 	return rc;
453 }
454 
455 /*----------------------------------------------------------------------
456 * Name:    hpc_readcmdtoindex()
457 *
458 * Action:  convert a read command to proper index within a controller
459 *
460 * Return   index, HPC_ERROR
461 *---------------------------------------------------------------------*/
462 static u8 hpc_readcmdtoindex(u8 cmd, u8 index)
463 {
464 	u8 rc;
465 
466 	switch (cmd) {
467 	case READ_CTLRSTATUS:
468 		rc = 0x0F;
469 		break;
470 	case READ_SLOTSTATUS:
471 	case READ_ALLSTAT:
472 		rc = index;
473 		break;
474 	case READ_EXTSLOTSTATUS:
475 		rc = index + WPG_1ST_EXTSLOT_INDEX;
476 		break;
477 	case READ_BUSSTATUS:
478 		rc = index + WPG_1ST_BUS_INDEX - 1;
479 		break;
480 	case READ_SLOTLATCHLOWREG:
481 		rc = 0x28;
482 		break;
483 	case READ_REVLEVEL:
484 		rc = 0x25;
485 		break;
486 	case READ_HPCOPTIONS:
487 		rc = 0x27;
488 		break;
489 	default:
490 		rc = HPC_ERROR;
491 	}
492 	return rc;
493 }
494 
495 /*----------------------------------------------------------------------
496 * Name:    HPCreadslot()
497 *
498 * Action:  issue a READ command to HPC
499 *
500 * Input:   pslot   - cannot be NULL for READ_ALLSTAT
501 *          pstatus - can be NULL for READ_ALLSTAT
502 *
503 * Return   0 or error codes
504 *---------------------------------------------------------------------*/
505 int ibmphp_hpc_readslot(struct slot *pslot, u8 cmd, u8 *pstatus)
506 {
507 	void __iomem *wpg_bbar = NULL;
508 	struct controller *ctlr_ptr;
509 	u8 index, status;
510 	int rc = 0;
511 	int busindex;
512 
513 	debug_polling("%s - Entry pslot[%p] cmd[%x] pstatus[%p]\n", __func__, pslot, cmd, pstatus);
514 
515 	if ((pslot == NULL)
516 	    || ((pstatus == NULL) && (cmd != READ_ALLSTAT) && (cmd != READ_BUSSTATUS))) {
517 		rc = -EINVAL;
518 		err("%s - Error invalid pointer, rc[%d]\n", __func__, rc);
519 		return rc;
520 	}
521 
522 	if (cmd == READ_BUSSTATUS) {
523 		busindex = ibmphp_get_bus_index(pslot->bus);
524 		if (busindex < 0) {
525 			rc = -EINVAL;
526 			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
527 			return rc;
528 		} else
529 			index = (u8) busindex;
530 	} else
531 		index = pslot->ctlr_index;
532 
533 	index = hpc_readcmdtoindex(cmd, index);
534 
535 	if (index == HPC_ERROR) {
536 		rc = -EINVAL;
537 		err("%s - Exit Error:invalid index, rc[%d]\n", __func__, rc);
538 		return rc;
539 	}
540 
541 	ctlr_ptr = pslot->ctrl;
542 
543 	get_hpc_access();
544 
545 	//--------------------------------------------------------------------
546 	// map physical address to logical address
547 	//--------------------------------------------------------------------
548 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
549 		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
550 
551 	//--------------------------------------------------------------------
552 	// check controller status before reading
553 	//--------------------------------------------------------------------
554 	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
555 	if (!rc) {
556 		switch (cmd) {
557 		case READ_ALLSTAT:
558 			// update the slot structure
559 			pslot->ctrl->status = status;
560 			pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
561 			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
562 						       &status);
563 			if (!rc)
564 				pslot->ext_status = ctrl_read(ctlr_ptr, wpg_bbar, index + WPG_1ST_EXTSLOT_INDEX);
565 
566 			break;
567 
568 		case READ_SLOTSTATUS:
569 			// DO NOT update the slot structure
570 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
571 			break;
572 
573 		case READ_EXTSLOTSTATUS:
574 			// DO NOT update the slot structure
575 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
576 			break;
577 
578 		case READ_CTLRSTATUS:
579 			// DO NOT update the slot structure
580 			*pstatus = status;
581 			break;
582 
583 		case READ_BUSSTATUS:
584 			pslot->busstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
585 			break;
586 		case READ_REVLEVEL:
587 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
588 			break;
589 		case READ_HPCOPTIONS:
590 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
591 			break;
592 		case READ_SLOTLATCHLOWREG:
593 			// DO NOT update the slot structure
594 			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
595 			break;
596 
597 			// Not used
598 		case READ_ALLSLOT:
599 			list_for_each_entry(pslot, &ibmphp_slot_head,
600 					    ibm_slot_list) {
601 				index = pslot->ctlr_index;
602 				rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr,
603 								wpg_bbar, &status);
604 				if (!rc) {
605 					pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
606 					rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT,
607 									ctlr_ptr, wpg_bbar, &status);
608 					if (!rc)
609 						pslot->ext_status =
610 						    ctrl_read(ctlr_ptr, wpg_bbar,
611 								index + WPG_1ST_EXTSLOT_INDEX);
612 				} else {
613 					err("%s - Error ctrl_read failed\n", __func__);
614 					rc = -EINVAL;
615 					break;
616 				}
617 			}
618 			break;
619 		default:
620 			rc = -EINVAL;
621 			break;
622 		}
623 	}
624 	//--------------------------------------------------------------------
625 	// cleanup
626 	//--------------------------------------------------------------------
627 
628 	// remove physical to logical address mapping
629 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
630 		iounmap(wpg_bbar);
631 
632 	free_hpc_access();
633 
634 	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
635 	return rc;
636 }
637 
638 /*----------------------------------------------------------------------
639 * Name:    ibmphp_hpc_writeslot()
640 *
641 * Action: issue a WRITE command to HPC
642 *---------------------------------------------------------------------*/
643 int ibmphp_hpc_writeslot(struct slot *pslot, u8 cmd)
644 {
645 	void __iomem *wpg_bbar = NULL;
646 	struct controller *ctlr_ptr;
647 	u8 index, status;
648 	int busindex;
649 	u8 done;
650 	int rc = 0;
651 	int timeout;
652 
653 	debug_polling("%s - Entry pslot[%p] cmd[%x]\n", __func__, pslot, cmd);
654 	if (pslot == NULL) {
655 		rc = -EINVAL;
656 		err("%s - Error Exit rc[%d]\n", __func__, rc);
657 		return rc;
658 	}
659 
660 	if ((cmd == HPC_BUS_33CONVMODE) || (cmd == HPC_BUS_66CONVMODE) ||
661 		(cmd == HPC_BUS_66PCIXMODE) || (cmd == HPC_BUS_100PCIXMODE) ||
662 		(cmd == HPC_BUS_133PCIXMODE)) {
663 		busindex = ibmphp_get_bus_index(pslot->bus);
664 		if (busindex < 0) {
665 			rc = -EINVAL;
666 			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
667 			return rc;
668 		} else
669 			index = (u8) busindex;
670 	} else
671 		index = pslot->ctlr_index;
672 
673 	index = hpc_writecmdtoindex(cmd, index);
674 
675 	if (index == HPC_ERROR) {
676 		rc = -EINVAL;
677 		err("%s - Error Exit rc[%d]\n", __func__, rc);
678 		return rc;
679 	}
680 
681 	ctlr_ptr = pslot->ctrl;
682 
683 	get_hpc_access();
684 
685 	//--------------------------------------------------------------------
686 	// map physical address to logical address
687 	//--------------------------------------------------------------------
688 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4)) {
689 		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
690 
691 		debug("%s - ctlr id[%x] physical[%lx] logical[%lx] i2c[%x]\n", __func__,
692 		ctlr_ptr->ctlr_id, (ulong) (ctlr_ptr->u.wpeg_ctlr.wpegbbar), (ulong) wpg_bbar,
693 		ctlr_ptr->u.wpeg_ctlr.i2c_addr);
694 	}
695 	//--------------------------------------------------------------------
696 	// check controller status before writing
697 	//--------------------------------------------------------------------
698 	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
699 	if (!rc) {
700 
701 		ctrl_write(ctlr_ptr, wpg_bbar, index, cmd);
702 
703 		//--------------------------------------------------------------------
704 		// check controller is still not working on the command
705 		//--------------------------------------------------------------------
706 		timeout = CMD_COMPLETE_TOUT_SEC;
707 		done = 0;
708 		while (!done) {
709 			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
710 							&status);
711 			if (!rc) {
712 				if (NEEDTOCHECK_CMDSTATUS(cmd)) {
713 					if (CTLR_FINISHED(status) == HPC_CTLR_FINISHED_YES)
714 						done = 1;
715 				} else
716 					done = 1;
717 			}
718 			if (!done) {
719 				msleep(1000);
720 				if (timeout < 1) {
721 					done = 1;
722 					err("%s - Error command complete timeout\n", __func__);
723 					rc = -EFAULT;
724 				} else
725 					timeout--;
726 			}
727 		}
728 		ctlr_ptr->status = status;
729 	}
730 	// cleanup
731 
732 	// remove physical to logical address mapping
733 	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
734 		iounmap(wpg_bbar);
735 	free_hpc_access();
736 
737 	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
738 	return rc;
739 }
740 
741 /*----------------------------------------------------------------------
742 * Name:    get_hpc_access()
743 *
744 * Action: make sure only one process can access HPC at one time
745 *---------------------------------------------------------------------*/
746 static void get_hpc_access(void)
747 {
748 	mutex_lock(&sem_hpcaccess);
749 }
750 
751 /*----------------------------------------------------------------------
752 * Name:    free_hpc_access()
753 *---------------------------------------------------------------------*/
754 void free_hpc_access(void)
755 {
756 	mutex_unlock(&sem_hpcaccess);
757 }
758 
759 /*----------------------------------------------------------------------
760 * Name:    ibmphp_lock_operations()
761 *
762 * Action: make sure only one process can change the data structure
763 *---------------------------------------------------------------------*/
764 void ibmphp_lock_operations(void)
765 {
766 	mutex_lock(&operations_mutex);
767 	to_debug = 1;
768 }
769 
770 /*----------------------------------------------------------------------
771 * Name:    ibmphp_unlock_operations()
772 *---------------------------------------------------------------------*/
773 void ibmphp_unlock_operations(void)
774 {
775 	debug("%s - Entry\n", __func__);
776 	mutex_unlock(&operations_mutex);
777 	to_debug = 0;
778 	debug("%s - Exit\n", __func__);
779 }
780 
781 /*----------------------------------------------------------------------
782 * Name:    poll_hpc()
783 *---------------------------------------------------------------------*/
784 #define POLL_LATCH_REGISTER	0
785 #define POLL_SLOTS		1
786 #define POLL_SLEEP		2
787 static int poll_hpc(void *data)
788 {
789 	struct slot myslot;
790 	struct slot *pslot = NULL;
791 	int rc;
792 	int poll_state = POLL_LATCH_REGISTER;
793 	u8 oldlatchlow = 0x00;
794 	u8 curlatchlow = 0x00;
795 	int poll_count = 0;
796 	u8 ctrl_count = 0x00;
797 
798 	debug("%s - Entry\n", __func__);
799 
800 	while (!kthread_should_stop()) {
801 		/* try to get the lock to do some kind of hardware access */
802 		mutex_lock(&operations_mutex);
803 
804 		switch (poll_state) {
805 		case POLL_LATCH_REGISTER:
806 			oldlatchlow = curlatchlow;
807 			ctrl_count = 0x00;
808 			list_for_each_entry(pslot, &ibmphp_slot_head,
809 					    ibm_slot_list) {
810 				if (ctrl_count >= ibmphp_get_total_controllers())
811 					break;
812 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
813 					ctrl_count++;
814 					if (READ_SLOT_LATCH(pslot->ctrl)) {
815 						rc = ibmphp_hpc_readslot(pslot,
816 									  READ_SLOTLATCHLOWREG,
817 									  &curlatchlow);
818 						if (oldlatchlow != curlatchlow)
819 							process_changeinlatch(oldlatchlow,
820 									       curlatchlow,
821 									       pslot->ctrl);
822 					}
823 				}
824 			}
825 			++poll_count;
826 			poll_state = POLL_SLEEP;
827 			break;
828 		case POLL_SLOTS:
829 			list_for_each_entry(pslot, &ibmphp_slot_head,
830 					    ibm_slot_list) {
831 				// make a copy of the old status
832 				memcpy((void *) &myslot, (void *) pslot,
833 					sizeof(struct slot));
834 				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
835 				if ((myslot.status != pslot->status)
836 				    || (myslot.ext_status != pslot->ext_status))
837 					process_changeinstatus(pslot, &myslot);
838 			}
839 			ctrl_count = 0x00;
840 			list_for_each_entry(pslot, &ibmphp_slot_head,
841 					    ibm_slot_list) {
842 				if (ctrl_count >= ibmphp_get_total_controllers())
843 					break;
844 				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
845 					ctrl_count++;
846 					if (READ_SLOT_LATCH(pslot->ctrl))
847 						rc = ibmphp_hpc_readslot(pslot,
848 									  READ_SLOTLATCHLOWREG,
849 									  &curlatchlow);
850 				}
851 			}
852 			++poll_count;
853 			poll_state = POLL_SLEEP;
854 			break;
855 		case POLL_SLEEP:
856 			/* don't sleep with a lock on the hardware */
857 			mutex_unlock(&operations_mutex);
858 			msleep(POLL_INTERVAL_SEC * 1000);
859 
860 			if (kthread_should_stop())
861 				goto out_sleep;
862 
863 			mutex_lock(&operations_mutex);
864 
865 			if (poll_count >= POLL_LATCH_CNT) {
866 				poll_count = 0;
867 				poll_state = POLL_SLOTS;
868 			} else
869 				poll_state = POLL_LATCH_REGISTER;
870 			break;
871 		}
872 		/* give up the hardware semaphore */
873 		mutex_unlock(&operations_mutex);
874 		/* sleep for a short time just for good measure */
875 out_sleep:
876 		msleep(100);
877 	}
878 	complete(&exit_complete);
879 	debug("%s - Exit\n", __func__);
880 	return 0;
881 }
882 
883 
884 /*----------------------------------------------------------------------
885 * Name:    process_changeinstatus
886 *
887 * Action:  compare old and new slot status, process the change in status
888 *
889 * Input:   pointer to slot struct, old slot struct
890 *
891 * Return   0 or error codes
892 * Value:
893 *
894 * Side
895 * Effects: None.
896 *
897 * Notes:
898 *---------------------------------------------------------------------*/
899 static int process_changeinstatus(struct slot *pslot, struct slot *poldslot)
900 {
901 	u8 status;
902 	int rc = 0;
903 	u8 disable = 0;
904 	u8 update = 0;
905 
906 	debug("process_changeinstatus - Entry pslot[%p], poldslot[%p]\n", pslot, poldslot);
907 
908 	// bit 0 - HPC_SLOT_POWER
909 	if ((pslot->status & 0x01) != (poldslot->status & 0x01))
910 		update = 1;
911 
912 	// bit 1 - HPC_SLOT_CONNECT
913 	// ignore
914 
915 	// bit 2 - HPC_SLOT_ATTN
916 	if ((pslot->status & 0x04) != (poldslot->status & 0x04))
917 		update = 1;
918 
919 	// bit 3 - HPC_SLOT_PRSNT2
920 	// bit 4 - HPC_SLOT_PRSNT1
921 	if (((pslot->status & 0x08) != (poldslot->status & 0x08))
922 		|| ((pslot->status & 0x10) != (poldslot->status & 0x10)))
923 		update = 1;
924 
925 	// bit 5 - HPC_SLOT_PWRGD
926 	if ((pslot->status & 0x20) != (poldslot->status & 0x20))
927 		// OFF -> ON: ignore, ON -> OFF: disable slot
928 		if ((poldslot->status & 0x20) && (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status)))
929 			disable = 1;
930 
931 	// bit 6 - HPC_SLOT_BUS_SPEED
932 	// ignore
933 
934 	// bit 7 - HPC_SLOT_LATCH
935 	if ((pslot->status & 0x80) != (poldslot->status & 0x80)) {
936 		update = 1;
937 		// OPEN -> CLOSE
938 		if (pslot->status & 0x80) {
939 			if (SLOT_PWRGD(pslot->status)) {
940 				// power goes on and off after closing latch
941 				// check again to make sure power is still ON
942 				msleep(1000);
943 				rc = ibmphp_hpc_readslot(pslot, READ_SLOTSTATUS, &status);
944 				if (SLOT_PWRGD(status))
945 					update = 1;
946 				else	// overwrite power in pslot to OFF
947 					pslot->status &= ~HPC_SLOT_POWER;
948 			}
949 		}
950 		// CLOSE -> OPEN
951 		else if ((SLOT_PWRGD(poldslot->status) == HPC_SLOT_PWRGD_GOOD)
952 			&& (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status))) {
953 			disable = 1;
954 		}
955 		// else - ignore
956 	}
957 	// bit 4 - HPC_SLOT_BLINK_ATTN
958 	if ((pslot->ext_status & 0x08) != (poldslot->ext_status & 0x08))
959 		update = 1;
960 
961 	if (disable) {
962 		debug("process_changeinstatus - disable slot\n");
963 		pslot->flag = 0;
964 		rc = ibmphp_do_disable_slot(pslot);
965 	}
966 
967 	if (update || disable)
968 		ibmphp_update_slot_info(pslot);
969 
970 	debug("%s - Exit rc[%d] disable[%x] update[%x]\n", __func__, rc, disable, update);
971 
972 	return rc;
973 }
974 
975 /*----------------------------------------------------------------------
976 * Name:    process_changeinlatch
977 *
978 * Action:  compare old and new latch reg status, process the change
979 *
980 * Input:   old and current latch register status
981 *
982 * Return   0 or error codes
983 * Value:
984 *---------------------------------------------------------------------*/
985 static int process_changeinlatch(u8 old, u8 new, struct controller *ctrl)
986 {
987 	struct slot myslot, *pslot;
988 	u8 i;
989 	u8 mask;
990 	int rc = 0;
991 
992 	debug("%s - Entry old[%x], new[%x]\n", __func__, old, new);
993 	// bit 0 reserved, 0 is LSB, check bit 1-6 for 6 slots
994 
995 	for (i = ctrl->starting_slot_num; i <= ctrl->ending_slot_num; i++) {
996 		mask = 0x01 << i;
997 		if ((mask & old) != (mask & new)) {
998 			pslot = ibmphp_get_slot_from_physical_num(i);
999 			if (pslot) {
1000 				memcpy((void *) &myslot, (void *) pslot, sizeof(struct slot));
1001 				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
1002 				debug("%s - call process_changeinstatus for slot[%d]\n", __func__, i);
1003 				process_changeinstatus(pslot, &myslot);
1004 			} else {
1005 				rc = -EINVAL;
1006 				err("%s - Error bad pointer for slot[%d]\n", __func__, i);
1007 			}
1008 		}
1009 	}
1010 	debug("%s - Exit rc[%d]\n", __func__, rc);
1011 	return rc;
1012 }
1013 
1014 /*----------------------------------------------------------------------
1015 * Name:    ibmphp_hpc_start_poll_thread
1016 *
1017 * Action:  start polling thread
1018 *---------------------------------------------------------------------*/
1019 int __init ibmphp_hpc_start_poll_thread(void)
1020 {
1021 	debug("%s - Entry\n", __func__);
1022 
1023 	ibmphp_poll_thread = kthread_run(poll_hpc, NULL, "hpc_poll");
1024 	if (IS_ERR(ibmphp_poll_thread)) {
1025 		err("%s - Error, thread not started\n", __func__);
1026 		return PTR_ERR(ibmphp_poll_thread);
1027 	}
1028 	return 0;
1029 }
1030 
1031 /*----------------------------------------------------------------------
1032 * Name:    ibmphp_hpc_stop_poll_thread
1033 *
1034 * Action:  stop polling thread and cleanup
1035 *---------------------------------------------------------------------*/
1036 void __exit ibmphp_hpc_stop_poll_thread(void)
1037 {
1038 	debug("%s - Entry\n", __func__);
1039 
1040 	kthread_stop(ibmphp_poll_thread);
1041 	debug("before locking operations\n");
1042 	ibmphp_lock_operations();
1043 	debug("after locking operations\n");
1044 
1045 	// wait for poll thread to exit
1046 	debug("before exit_complete down\n");
1047 	wait_for_completion(&exit_complete);
1048 	debug("after exit_completion down\n");
1049 
1050 	// cleanup
1051 	debug("before free_hpc_access\n");
1052 	free_hpc_access();
1053 	debug("after free_hpc_access\n");
1054 	ibmphp_unlock_operations();
1055 	debug("after unlock operations\n");
1056 
1057 	debug("%s - Exit\n", __func__);
1058 }
1059 
1060 /*----------------------------------------------------------------------
1061 * Name:    hpc_wait_ctlr_notworking
1062 *
1063 * Action:  wait until the controller is in a not working state
1064 *
1065 * Return   0, HPC_ERROR
1066 * Value:
1067 *---------------------------------------------------------------------*/
1068 static int hpc_wait_ctlr_notworking(int timeout, struct controller *ctlr_ptr, void __iomem *wpg_bbar,
1069 				    u8 *pstatus)
1070 {
1071 	int rc = 0;
1072 	u8 done = 0;
1073 
1074 	debug_polling("hpc_wait_ctlr_notworking - Entry timeout[%d]\n", timeout);
1075 
1076 	while (!done) {
1077 		*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, WPG_CTLR_INDEX);
1078 		if (*pstatus == HPC_ERROR) {
1079 			rc = HPC_ERROR;
1080 			done = 1;
1081 		}
1082 		if (CTLR_WORKING(*pstatus) == HPC_CTLR_WORKING_NO)
1083 			done = 1;
1084 		if (!done) {
1085 			msleep(1000);
1086 			if (timeout < 1) {
1087 				done = 1;
1088 				err("HPCreadslot - Error ctlr timeout\n");
1089 				rc = HPC_ERROR;
1090 			} else
1091 				timeout--;
1092 		}
1093 	}
1094 	debug_polling("hpc_wait_ctlr_notworking - Exit rc[%x] status[%x]\n", rc, *pstatus);
1095 	return rc;
1096 }
1097