1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * ipmi_ssif.c
4 *
5 * The interface to the IPMI driver for SMBus access to a SMBus
6 * compliant device.  Called SSIF by the IPMI spec.
7 *
8 * Author: Intel Corporation
9 *         Todd Davis <todd.c.davis@intel.com>
10 *
11 * Rewritten by Corey Minyard <minyard@acm.org> to support the
12 * non-blocking I2C interface, add support for multi-part
13 * transactions, add PEC support, and general clenaup.
14 *
15 * Copyright 2003 Intel Corporation
16 * Copyright 2005 MontaVista Software
17 */
18
19/*
20 * This file holds the "policy" for the interface to the SSIF state
21 * machine.  It does the configuration, handles timers and interrupts,
22 * and drives the real SSIF state machine.
23 */
24
25#define pr_fmt(fmt) "ipmi_ssif: " fmt
26#define dev_fmt(fmt) "ipmi_ssif: " fmt
27
28#if defined(MODVERSIONS)
29#include <linux/modversions.h>
30#endif
31
32#include <linux/module.h>
33#include <linux/moduleparam.h>
34#include <linux/sched.h>
35#include <linux/seq_file.h>
36#include <linux/timer.h>
37#include <linux/delay.h>
38#include <linux/errno.h>
39#include <linux/spinlock.h>
40#include <linux/slab.h>
41#include <linux/list.h>
42#include <linux/i2c.h>
43#include <linux/ipmi_smi.h>
44#include <linux/init.h>
45#include <linux/dmi.h>
46#include <linux/kthread.h>
47#include <linux/acpi.h>
48#include <linux/ctype.h>
49#include <linux/time64.h>
50#include "ipmi_dmi.h"
51
52#define DEVICE_NAME "ipmi_ssif"
53
54#define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD	0x57
55
56#define	SSIF_IPMI_REQUEST			2
57#define	SSIF_IPMI_MULTI_PART_REQUEST_START	6
58#define	SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE	7
59#define	SSIF_IPMI_MULTI_PART_REQUEST_END	8
60#define	SSIF_IPMI_RESPONSE			3
61#define	SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE	9
62
63/* ssif_debug is a bit-field
64 *	SSIF_DEBUG_MSG -	commands and their responses
65 *	SSIF_DEBUG_STATES -	message states
66 *	SSIF_DEBUG_TIMING -	 Measure times between events in the driver
67 */
68#define SSIF_DEBUG_TIMING	4
69#define SSIF_DEBUG_STATE	2
70#define SSIF_DEBUG_MSG		1
71#define SSIF_NODEBUG		0
72#define SSIF_DEFAULT_DEBUG	(SSIF_NODEBUG)
73
74/*
75 * Timer values
76 */
77#define SSIF_MSG_USEC		60000	/* 60ms between message tries (T3). */
78#define SSIF_REQ_RETRY_USEC	60000	/* 60ms between send retries (T6). */
79#define SSIF_MSG_PART_USEC	5000	/* 5ms for a message part */
80
81/* How many times to we retry sending/receiving the message. */
82#define	SSIF_SEND_RETRIES	5
83#define	SSIF_RECV_RETRIES	250
84
85#define SSIF_MSG_MSEC		(SSIF_MSG_USEC / 1000)
86#define SSIF_REQ_RETRY_MSEC	(SSIF_REQ_RETRY_USEC / 1000)
87#define SSIF_MSG_JIFFIES	((SSIF_MSG_USEC * 1000) / TICK_NSEC)
88#define SSIF_REQ_RETRY_JIFFIES	((SSIF_REQ_RETRY_USEC * 1000) / TICK_NSEC)
89#define SSIF_MSG_PART_JIFFIES	((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
90
91/*
92 * Timeout for the watch, only used for get flag timer.
93 */
94#define SSIF_WATCH_MSG_TIMEOUT		msecs_to_jiffies(10)
95#define SSIF_WATCH_WATCHDOG_TIMEOUT	msecs_to_jiffies(250)
96
97enum ssif_intf_state {
98	SSIF_IDLE,
99	SSIF_GETTING_FLAGS,
100	SSIF_GETTING_EVENTS,
101	SSIF_CLEARING_FLAGS,
102	SSIF_GETTING_MESSAGES,
103	/* FIXME - add watchdog stuff. */
104};
105
106#define IS_SSIF_IDLE(ssif) ((ssif)->ssif_state == SSIF_IDLE \
107			    && (ssif)->curr_msg == NULL)
108
109/*
110 * Indexes into stats[] in ssif_info below.
111 */
112enum ssif_stat_indexes {
113	/* Number of total messages sent. */
114	SSIF_STAT_sent_messages = 0,
115
116	/*
117	 * Number of message parts sent.  Messages may be broken into
118	 * parts if they are long.
119	 */
120	SSIF_STAT_sent_messages_parts,
121
122	/*
123	 * Number of time a message was retried.
124	 */
125	SSIF_STAT_send_retries,
126
127	/*
128	 * Number of times the send of a message failed.
129	 */
130	SSIF_STAT_send_errors,
131
132	/*
133	 * Number of message responses received.
134	 */
135	SSIF_STAT_received_messages,
136
137	/*
138	 * Number of message fragments received.
139	 */
140	SSIF_STAT_received_message_parts,
141
142	/*
143	 * Number of times the receive of a message was retried.
144	 */
145	SSIF_STAT_receive_retries,
146
147	/*
148	 * Number of errors receiving messages.
149	 */
150	SSIF_STAT_receive_errors,
151
152	/*
153	 * Number of times a flag fetch was requested.
154	 */
155	SSIF_STAT_flag_fetches,
156
157	/*
158	 * Number of times the hardware didn't follow the state machine.
159	 */
160	SSIF_STAT_hosed,
161
162	/*
163	 * Number of received events.
164	 */
165	SSIF_STAT_events,
166
167	/* Number of asyncronous messages received. */
168	SSIF_STAT_incoming_messages,
169
170	/* Number of watchdog pretimeouts. */
171	SSIF_STAT_watchdog_pretimeouts,
172
173	/* Number of alers received. */
174	SSIF_STAT_alerts,
175
176	/* Always add statistics before this value, it must be last. */
177	SSIF_NUM_STATS
178};
179
180struct ssif_addr_info {
181	struct i2c_board_info binfo;
182	char *adapter_name;
183	int debug;
184	int slave_addr;
185	enum ipmi_addr_src addr_src;
186	union ipmi_smi_info_union addr_info;
187	struct device *dev;
188	struct i2c_client *client;
189
190	struct mutex clients_mutex;
191	struct list_head clients;
192
193	struct list_head link;
194};
195
196struct ssif_info;
197
198typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
199			     unsigned char *data, unsigned int len);
200
201struct ssif_info {
202	struct ipmi_smi     *intf;
203	spinlock_t	    lock;
204	struct ipmi_smi_msg *waiting_msg;
205	struct ipmi_smi_msg *curr_msg;
206	enum ssif_intf_state ssif_state;
207	unsigned long       ssif_debug;
208
209	struct ipmi_smi_handlers handlers;
210
211	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
212	union ipmi_smi_info_union addr_info;
213
214	/*
215	 * Flags from the last GET_MSG_FLAGS command, used when an ATTN
216	 * is set to hold the flags until we are done handling everything
217	 * from the flags.
218	 */
219#define RECEIVE_MSG_AVAIL	0x01
220#define EVENT_MSG_BUFFER_FULL	0x02
221#define WDT_PRE_TIMEOUT_INT	0x08
222	unsigned char       msg_flags;
223
224	u8		    global_enables;
225	bool		    has_event_buffer;
226	bool		    supports_alert;
227
228	/*
229	 * Used to tell what we should do with alerts.  If we are
230	 * waiting on a response, read the data immediately.
231	 */
232	bool		    got_alert;
233	bool		    waiting_alert;
234
235	/* Used to inform the timeout that it should do a resend. */
236	bool		    do_resend;
237
238	/*
239	 * If set to true, this will request events the next time the
240	 * state machine is idle.
241	 */
242	bool                req_events;
243
244	/*
245	 * If set to true, this will request flags the next time the
246	 * state machine is idle.
247	 */
248	bool                req_flags;
249
250	/*
251	 * Used to perform timer operations when run-to-completion
252	 * mode is on.  This is a countdown timer.
253	 */
254	int                 rtc_us_timer;
255
256	/* Used for sending/receiving data.  +1 for the length. */
257	unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
258	unsigned int  data_len;
259
260	/* Temp receive buffer, gets copied into data. */
261	unsigned char recv[I2C_SMBUS_BLOCK_MAX];
262
263	struct i2c_client *client;
264	ssif_i2c_done done_handler;
265
266	/* Thread interface handling */
267	struct task_struct *thread;
268	struct completion wake_thread;
269	bool stopping;
270	int i2c_read_write;
271	int i2c_command;
272	unsigned char *i2c_data;
273	unsigned int i2c_size;
274
275	struct timer_list retry_timer;
276	int retries_left;
277
278	long watch_timeout;		/* Timeout for flags check, 0 if off. */
279	struct timer_list watch_timer;	/* Flag fetch timer. */
280
281	/* Info from SSIF cmd */
282	unsigned char max_xmit_msg_size;
283	unsigned char max_recv_msg_size;
284	bool cmd8_works; /* See test_multipart_messages() for details. */
285	unsigned int  multi_support;
286	int           supports_pec;
287
288#define SSIF_NO_MULTI		0
289#define SSIF_MULTI_2_PART	1
290#define SSIF_MULTI_n_PART	2
291	unsigned char *multi_data;
292	unsigned int  multi_len;
293	unsigned int  multi_pos;
294
295	atomic_t stats[SSIF_NUM_STATS];
296};
297
298#define ssif_inc_stat(ssif, stat) \
299	atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
300#define ssif_get_stat(ssif, stat) \
301	((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
302
303static bool initialized;
304static bool platform_registered;
305
306static void return_hosed_msg(struct ssif_info *ssif_info,
307			     struct ipmi_smi_msg *msg);
308static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
309static int start_send(struct ssif_info *ssif_info,
310		      unsigned char   *data,
311		      unsigned int    len);
312
313static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
314					  unsigned long *flags)
315	__acquires(&ssif_info->lock)
316{
317	spin_lock_irqsave(&ssif_info->lock, *flags);
318	return flags;
319}
320
321static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
322				  unsigned long *flags)
323	__releases(&ssif_info->lock)
324{
325	spin_unlock_irqrestore(&ssif_info->lock, *flags);
326}
327
328static void deliver_recv_msg(struct ssif_info *ssif_info,
329			     struct ipmi_smi_msg *msg)
330{
331	if (msg->rsp_size < 0) {
332		return_hosed_msg(ssif_info, msg);
333		dev_err(&ssif_info->client->dev,
334			"%s: Malformed message: rsp_size = %d\n",
335		       __func__, msg->rsp_size);
336	} else {
337		ipmi_smi_msg_received(ssif_info->intf, msg);
338	}
339}
340
341static void return_hosed_msg(struct ssif_info *ssif_info,
342			     struct ipmi_smi_msg *msg)
343{
344	ssif_inc_stat(ssif_info, hosed);
345
346	/* Make it a response */
347	msg->rsp[0] = msg->data[0] | 4;
348	msg->rsp[1] = msg->data[1];
349	msg->rsp[2] = 0xFF; /* Unknown error. */
350	msg->rsp_size = 3;
351
352	deliver_recv_msg(ssif_info, msg);
353}
354
355/*
356 * Must be called with the message lock held.  This will release the
357 * message lock.  Note that the caller will check IS_SSIF_IDLE and
358 * start a new operation, so there is no need to check for new
359 * messages to start in here.
360 */
361static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
362{
363	unsigned char msg[3];
364
365	ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
366	ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
367	ipmi_ssif_unlock_cond(ssif_info, flags);
368
369	/* Make sure the watchdog pre-timeout flag is not set at startup. */
370	msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
371	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
372	msg[2] = WDT_PRE_TIMEOUT_INT;
373
374	if (start_send(ssif_info, msg, 3) != 0) {
375		/* Error, just go to normal state. */
376		ssif_info->ssif_state = SSIF_IDLE;
377	}
378}
379
380static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
381{
382	unsigned char mb[2];
383
384	ssif_info->req_flags = false;
385	ssif_info->ssif_state = SSIF_GETTING_FLAGS;
386	ipmi_ssif_unlock_cond(ssif_info, flags);
387
388	mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
389	mb[1] = IPMI_GET_MSG_FLAGS_CMD;
390	if (start_send(ssif_info, mb, 2) != 0)
391		ssif_info->ssif_state = SSIF_IDLE;
392}
393
394static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
395			     struct ipmi_smi_msg *msg)
396{
397	if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
398		unsigned long oflags;
399
400		flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
401		ssif_info->curr_msg = NULL;
402		ssif_info->ssif_state = SSIF_IDLE;
403		ipmi_ssif_unlock_cond(ssif_info, flags);
404		ipmi_free_smi_msg(msg);
405	}
406}
407
408static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
409{
410	struct ipmi_smi_msg *msg;
411
412	ssif_info->req_events = false;
413
414	msg = ipmi_alloc_smi_msg();
415	if (!msg) {
416		ssif_info->ssif_state = SSIF_IDLE;
417		ipmi_ssif_unlock_cond(ssif_info, flags);
418		return;
419	}
420
421	ssif_info->curr_msg = msg;
422	ssif_info->ssif_state = SSIF_GETTING_EVENTS;
423	ipmi_ssif_unlock_cond(ssif_info, flags);
424
425	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
426	msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
427	msg->data_size = 2;
428
429	check_start_send(ssif_info, flags, msg);
430}
431
432static void start_recv_msg_fetch(struct ssif_info *ssif_info,
433				 unsigned long *flags)
434{
435	struct ipmi_smi_msg *msg;
436
437	msg = ipmi_alloc_smi_msg();
438	if (!msg) {
439		ssif_info->ssif_state = SSIF_IDLE;
440		ipmi_ssif_unlock_cond(ssif_info, flags);
441		return;
442	}
443
444	ssif_info->curr_msg = msg;
445	ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
446	ipmi_ssif_unlock_cond(ssif_info, flags);
447
448	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
449	msg->data[1] = IPMI_GET_MSG_CMD;
450	msg->data_size = 2;
451
452	check_start_send(ssif_info, flags, msg);
453}
454
455/*
456 * Must be called with the message lock held.  This will release the
457 * message lock.  Note that the caller will check IS_SSIF_IDLE and
458 * start a new operation, so there is no need to check for new
459 * messages to start in here.
460 */
461static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
462{
463	if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
464		/* Watchdog pre-timeout */
465		ssif_inc_stat(ssif_info, watchdog_pretimeouts);
466		start_clear_flags(ssif_info, flags);
467		ipmi_smi_watchdog_pretimeout(ssif_info->intf);
468	} else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
469		/* Messages available. */
470		start_recv_msg_fetch(ssif_info, flags);
471	else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
472		/* Events available. */
473		start_event_fetch(ssif_info, flags);
474	else {
475		ssif_info->ssif_state = SSIF_IDLE;
476		ipmi_ssif_unlock_cond(ssif_info, flags);
477	}
478}
479
480static int ipmi_ssif_thread(void *data)
481{
482	struct ssif_info *ssif_info = data;
483
484	while (!kthread_should_stop()) {
485		int result;
486
487		/* Wait for something to do */
488		result = wait_for_completion_interruptible(
489						&ssif_info->wake_thread);
490		if (ssif_info->stopping)
491			break;
492		if (result == -ERESTARTSYS)
493			continue;
494		init_completion(&ssif_info->wake_thread);
495
496		if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
497			result = i2c_smbus_write_block_data(
498				ssif_info->client, ssif_info->i2c_command,
499				ssif_info->i2c_data[0],
500				ssif_info->i2c_data + 1);
501			ssif_info->done_handler(ssif_info, result, NULL, 0);
502		} else {
503			result = i2c_smbus_read_block_data(
504				ssif_info->client, ssif_info->i2c_command,
505				ssif_info->i2c_data);
506			if (result < 0)
507				ssif_info->done_handler(ssif_info, result,
508							NULL, 0);
509			else
510				ssif_info->done_handler(ssif_info, 0,
511							ssif_info->i2c_data,
512							result);
513		}
514	}
515
516	return 0;
517}
518
519static void ssif_i2c_send(struct ssif_info *ssif_info,
520			ssif_i2c_done handler,
521			int read_write, int command,
522			unsigned char *data, unsigned int size)
523{
524	ssif_info->done_handler = handler;
525
526	ssif_info->i2c_read_write = read_write;
527	ssif_info->i2c_command = command;
528	ssif_info->i2c_data = data;
529	ssif_info->i2c_size = size;
530	complete(&ssif_info->wake_thread);
531}
532
533
534static void msg_done_handler(struct ssif_info *ssif_info, int result,
535			     unsigned char *data, unsigned int len);
536
537static void start_get(struct ssif_info *ssif_info)
538{
539	ssif_info->rtc_us_timer = 0;
540	ssif_info->multi_pos = 0;
541
542	ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
543		  SSIF_IPMI_RESPONSE,
544		  ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
545}
546
547static void start_resend(struct ssif_info *ssif_info);
548
549static void retry_timeout(struct timer_list *t)
550{
551	struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
552	unsigned long oflags, *flags;
553	bool waiting, resend;
554
555	if (ssif_info->stopping)
556		return;
557
558	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
559	resend = ssif_info->do_resend;
560	ssif_info->do_resend = false;
561	waiting = ssif_info->waiting_alert;
562	ssif_info->waiting_alert = false;
563	ipmi_ssif_unlock_cond(ssif_info, flags);
564
565	if (waiting)
566		start_get(ssif_info);
567	if (resend) {
568		start_resend(ssif_info);
569		ssif_inc_stat(ssif_info, send_retries);
570	}
571}
572
573static void watch_timeout(struct timer_list *t)
574{
575	struct ssif_info *ssif_info = from_timer(ssif_info, t, watch_timer);
576	unsigned long oflags, *flags;
577
578	if (ssif_info->stopping)
579		return;
580
581	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
582	if (ssif_info->watch_timeout) {
583		mod_timer(&ssif_info->watch_timer,
584			  jiffies + ssif_info->watch_timeout);
585		if (IS_SSIF_IDLE(ssif_info)) {
586			start_flag_fetch(ssif_info, flags); /* Releases lock */
587			return;
588		}
589		ssif_info->req_flags = true;
590	}
591	ipmi_ssif_unlock_cond(ssif_info, flags);
592}
593
594static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
595		       unsigned int data)
596{
597	struct ssif_info *ssif_info = i2c_get_clientdata(client);
598	unsigned long oflags, *flags;
599	bool do_get = false;
600
601	if (type != I2C_PROTOCOL_SMBUS_ALERT)
602		return;
603
604	ssif_inc_stat(ssif_info, alerts);
605
606	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
607	if (ssif_info->waiting_alert) {
608		ssif_info->waiting_alert = false;
609		del_timer(&ssif_info->retry_timer);
610		do_get = true;
611	} else if (ssif_info->curr_msg) {
612		ssif_info->got_alert = true;
613	}
614	ipmi_ssif_unlock_cond(ssif_info, flags);
615	if (do_get)
616		start_get(ssif_info);
617}
618
619static void msg_done_handler(struct ssif_info *ssif_info, int result,
620			     unsigned char *data, unsigned int len)
621{
622	struct ipmi_smi_msg *msg;
623	unsigned long oflags, *flags;
624
625	/*
626	 * We are single-threaded here, so no need for a lock until we
627	 * start messing with driver states or the queues.
628	 */
629
630	if (result < 0) {
631		ssif_info->retries_left--;
632		if (ssif_info->retries_left > 0) {
633			ssif_inc_stat(ssif_info, receive_retries);
634
635			flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
636			ssif_info->waiting_alert = true;
637			ssif_info->rtc_us_timer = SSIF_MSG_USEC;
638			if (!ssif_info->stopping)
639				mod_timer(&ssif_info->retry_timer,
640					  jiffies + SSIF_MSG_JIFFIES);
641			ipmi_ssif_unlock_cond(ssif_info, flags);
642			return;
643		}
644
645		ssif_inc_stat(ssif_info, receive_errors);
646
647		if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
648			dev_dbg(&ssif_info->client->dev,
649				"%s: Error %d\n", __func__, result);
650		len = 0;
651		goto continue_op;
652	}
653
654	if ((len > 1) && (ssif_info->multi_pos == 0)
655				&& (data[0] == 0x00) && (data[1] == 0x01)) {
656		/* Start of multi-part read.  Start the next transaction. */
657		int i;
658
659		ssif_inc_stat(ssif_info, received_message_parts);
660
661		/* Remove the multi-part read marker. */
662		len -= 2;
663		data += 2;
664		for (i = 0; i < len; i++)
665			ssif_info->data[i] = data[i];
666		ssif_info->multi_len = len;
667		ssif_info->multi_pos = 1;
668
669		ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
670			 SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
671			 ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
672		return;
673	} else if (ssif_info->multi_pos) {
674		/* Middle of multi-part read.  Start the next transaction. */
675		int i;
676		unsigned char blocknum;
677
678		if (len == 0) {
679			result = -EIO;
680			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
681				dev_dbg(&ssif_info->client->dev,
682					"Middle message with no data\n");
683
684			goto continue_op;
685		}
686
687		blocknum = data[0];
688		len--;
689		data++;
690
691		if (blocknum != 0xff && len != 31) {
692		    /* All blocks but the last must have 31 data bytes. */
693			result = -EIO;
694			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
695				dev_dbg(&ssif_info->client->dev,
696					"Received middle message <31\n");
697
698			goto continue_op;
699		}
700
701		if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
702			/* Received message too big, abort the operation. */
703			result = -E2BIG;
704			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
705				dev_dbg(&ssif_info->client->dev,
706					"Received message too big\n");
707
708			goto continue_op;
709		}
710
711		for (i = 0; i < len; i++)
712			ssif_info->data[i + ssif_info->multi_len] = data[i];
713		ssif_info->multi_len += len;
714		if (blocknum == 0xff) {
715			/* End of read */
716			len = ssif_info->multi_len;
717			data = ssif_info->data;
718		} else if (blocknum + 1 != ssif_info->multi_pos) {
719			/*
720			 * Out of sequence block, just abort.  Block
721			 * numbers start at zero for the second block,
722			 * but multi_pos starts at one, so the +1.
723			 */
724			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
725				dev_dbg(&ssif_info->client->dev,
726					"Received message out of sequence, expected %u, got %u\n",
727					ssif_info->multi_pos - 1, blocknum);
728			result = -EIO;
729		} else {
730			ssif_inc_stat(ssif_info, received_message_parts);
731
732			ssif_info->multi_pos++;
733
734			ssif_i2c_send(ssif_info, msg_done_handler,
735				  I2C_SMBUS_READ,
736				  SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
737				  ssif_info->recv,
738				  I2C_SMBUS_BLOCK_DATA);
739			return;
740		}
741	}
742
743 continue_op:
744	if (result < 0) {
745		ssif_inc_stat(ssif_info, receive_errors);
746	} else {
747		ssif_inc_stat(ssif_info, received_messages);
748		ssif_inc_stat(ssif_info, received_message_parts);
749	}
750
751	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
752		dev_dbg(&ssif_info->client->dev,
753			"DONE 1: state = %d, result=%d\n",
754			ssif_info->ssif_state, result);
755
756	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
757	msg = ssif_info->curr_msg;
758	if (msg) {
759		if (data) {
760			if (len > IPMI_MAX_MSG_LENGTH)
761				len = IPMI_MAX_MSG_LENGTH;
762			memcpy(msg->rsp, data, len);
763		} else {
764			len = 0;
765		}
766		msg->rsp_size = len;
767		ssif_info->curr_msg = NULL;
768	}
769
770	switch (ssif_info->ssif_state) {
771	case SSIF_IDLE:
772		ipmi_ssif_unlock_cond(ssif_info, flags);
773		if (!msg)
774			break;
775
776		if (result < 0)
777			return_hosed_msg(ssif_info, msg);
778		else
779			deliver_recv_msg(ssif_info, msg);
780		break;
781
782	case SSIF_GETTING_FLAGS:
783		/* We got the flags from the SSIF, now handle them. */
784		if ((result < 0) || (len < 4) || (data[2] != 0)) {
785			/*
786			 * Error fetching flags, or invalid length,
787			 * just give up for now.
788			 */
789			ssif_info->ssif_state = SSIF_IDLE;
790			ipmi_ssif_unlock_cond(ssif_info, flags);
791			dev_warn(&ssif_info->client->dev,
792				 "Error getting flags: %d %d, %x\n",
793				 result, len, (len >= 3) ? data[2] : 0);
794		} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
795			   || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
796			/*
797			 * Recv error response, give up.
798			 */
799			ssif_info->ssif_state = SSIF_IDLE;
800			ipmi_ssif_unlock_cond(ssif_info, flags);
801			dev_warn(&ssif_info->client->dev,
802				 "Invalid response getting flags: %x %x\n",
803				 data[0], data[1]);
804		} else {
805			ssif_inc_stat(ssif_info, flag_fetches);
806			ssif_info->msg_flags = data[3];
807			handle_flags(ssif_info, flags);
808		}
809		break;
810
811	case SSIF_CLEARING_FLAGS:
812		/* We cleared the flags. */
813		if ((result < 0) || (len < 3) || (data[2] != 0)) {
814			/* Error clearing flags */
815			dev_warn(&ssif_info->client->dev,
816				 "Error clearing flags: %d %d, %x\n",
817				 result, len, (len >= 3) ? data[2] : 0);
818		} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
819			   || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
820			dev_warn(&ssif_info->client->dev,
821				 "Invalid response clearing flags: %x %x\n",
822				 data[0], data[1]);
823		}
824		ssif_info->ssif_state = SSIF_IDLE;
825		ipmi_ssif_unlock_cond(ssif_info, flags);
826		break;
827
828	case SSIF_GETTING_EVENTS:
829		if (!msg) {
830			/* Should never happen, but just in case. */
831			dev_warn(&ssif_info->client->dev,
832				 "No message set while getting events\n");
833			ipmi_ssif_unlock_cond(ssif_info, flags);
834			break;
835		}
836
837		if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
838			/* Error getting event, probably done. */
839			msg->done(msg);
840
841			/* Take off the event flag. */
842			ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
843			handle_flags(ssif_info, flags);
844		} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
845			   || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
846			dev_warn(&ssif_info->client->dev,
847				 "Invalid response getting events: %x %x\n",
848				 msg->rsp[0], msg->rsp[1]);
849			msg->done(msg);
850			/* Take off the event flag. */
851			ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
852			handle_flags(ssif_info, flags);
853		} else {
854			handle_flags(ssif_info, flags);
855			ssif_inc_stat(ssif_info, events);
856			deliver_recv_msg(ssif_info, msg);
857		}
858		break;
859
860	case SSIF_GETTING_MESSAGES:
861		if (!msg) {
862			/* Should never happen, but just in case. */
863			dev_warn(&ssif_info->client->dev,
864				 "No message set while getting messages\n");
865			ipmi_ssif_unlock_cond(ssif_info, flags);
866			break;
867		}
868
869		if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
870			/* Error getting event, probably done. */
871			msg->done(msg);
872
873			/* Take off the msg flag. */
874			ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
875			handle_flags(ssif_info, flags);
876		} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
877			   || msg->rsp[1] != IPMI_GET_MSG_CMD) {
878			dev_warn(&ssif_info->client->dev,
879				 "Invalid response clearing flags: %x %x\n",
880				 msg->rsp[0], msg->rsp[1]);
881			msg->done(msg);
882
883			/* Take off the msg flag. */
884			ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
885			handle_flags(ssif_info, flags);
886		} else {
887			ssif_inc_stat(ssif_info, incoming_messages);
888			handle_flags(ssif_info, flags);
889			deliver_recv_msg(ssif_info, msg);
890		}
891		break;
892
893	default:
894		/* Should never happen, but just in case. */
895		dev_warn(&ssif_info->client->dev,
896			 "Invalid state in message done handling: %d\n",
897			 ssif_info->ssif_state);
898		ipmi_ssif_unlock_cond(ssif_info, flags);
899	}
900
901	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
902	if (IS_SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
903		if (ssif_info->req_events)
904			start_event_fetch(ssif_info, flags);
905		else if (ssif_info->req_flags)
906			start_flag_fetch(ssif_info, flags);
907		else
908			start_next_msg(ssif_info, flags);
909	} else
910		ipmi_ssif_unlock_cond(ssif_info, flags);
911
912	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
913		dev_dbg(&ssif_info->client->dev,
914			"DONE 2: state = %d.\n", ssif_info->ssif_state);
915}
916
917static void msg_written_handler(struct ssif_info *ssif_info, int result,
918				unsigned char *data, unsigned int len)
919{
920	/* We are single-threaded here, so no need for a lock. */
921	if (result < 0) {
922		ssif_info->retries_left--;
923		if (ssif_info->retries_left > 0) {
924			/*
925			 * Wait the retry timeout time per the spec,
926			 * then redo the send.
927			 */
928			ssif_info->do_resend = true;
929			mod_timer(&ssif_info->retry_timer,
930				  jiffies + SSIF_REQ_RETRY_JIFFIES);
931			return;
932		}
933
934		ssif_inc_stat(ssif_info, send_errors);
935
936		if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
937			dev_dbg(&ssif_info->client->dev,
938				"%s: Out of retries\n", __func__);
939
940		msg_done_handler(ssif_info, -EIO, NULL, 0);
941		return;
942	}
943
944	if (ssif_info->multi_data) {
945		/*
946		 * In the middle of a multi-data write.  See the comment
947		 * in the SSIF_MULTI_n_PART case in the probe function
948		 * for details on the intricacies of this.
949		 */
950		int left, to_write;
951		unsigned char *data_to_send;
952		unsigned char cmd;
953
954		ssif_inc_stat(ssif_info, sent_messages_parts);
955
956		left = ssif_info->multi_len - ssif_info->multi_pos;
957		to_write = left;
958		if (to_write > 32)
959			to_write = 32;
960		/* Length byte. */
961		ssif_info->multi_data[ssif_info->multi_pos] = to_write;
962		data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
963		ssif_info->multi_pos += to_write;
964		cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
965		if (ssif_info->cmd8_works) {
966			if (left == to_write) {
967				cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
968				ssif_info->multi_data = NULL;
969			}
970		} else if (to_write < 32) {
971			ssif_info->multi_data = NULL;
972		}
973
974		ssif_i2c_send(ssif_info, msg_written_handler,
975			  I2C_SMBUS_WRITE, cmd,
976			  data_to_send, I2C_SMBUS_BLOCK_DATA);
977	} else {
978		/* Ready to request the result. */
979		unsigned long oflags, *flags;
980
981		ssif_inc_stat(ssif_info, sent_messages);
982		ssif_inc_stat(ssif_info, sent_messages_parts);
983
984		flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
985		if (ssif_info->got_alert) {
986			/* The result is already ready, just start it. */
987			ssif_info->got_alert = false;
988			ipmi_ssif_unlock_cond(ssif_info, flags);
989			start_get(ssif_info);
990		} else {
991			/* Wait a jiffie then request the next message */
992			ssif_info->waiting_alert = true;
993			ssif_info->retries_left = SSIF_RECV_RETRIES;
994			ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
995			if (!ssif_info->stopping)
996				mod_timer(&ssif_info->retry_timer,
997					  jiffies + SSIF_MSG_PART_JIFFIES);
998			ipmi_ssif_unlock_cond(ssif_info, flags);
999		}
1000	}
1001}
1002
1003static void start_resend(struct ssif_info *ssif_info)
1004{
1005	int command;
1006
1007	ssif_info->got_alert = false;
1008
1009	if (ssif_info->data_len > 32) {
1010		command = SSIF_IPMI_MULTI_PART_REQUEST_START;
1011		ssif_info->multi_data = ssif_info->data;
1012		ssif_info->multi_len = ssif_info->data_len;
1013		/*
1014		 * Subtle thing, this is 32, not 33, because we will
1015		 * overwrite the thing at position 32 (which was just
1016		 * transmitted) with the new length.
1017		 */
1018		ssif_info->multi_pos = 32;
1019		ssif_info->data[0] = 32;
1020	} else {
1021		ssif_info->multi_data = NULL;
1022		command = SSIF_IPMI_REQUEST;
1023		ssif_info->data[0] = ssif_info->data_len;
1024	}
1025
1026	ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
1027		   command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1028}
1029
1030static int start_send(struct ssif_info *ssif_info,
1031		      unsigned char   *data,
1032		      unsigned int    len)
1033{
1034	if (len > IPMI_MAX_MSG_LENGTH)
1035		return -E2BIG;
1036	if (len > ssif_info->max_xmit_msg_size)
1037		return -E2BIG;
1038
1039	ssif_info->retries_left = SSIF_SEND_RETRIES;
1040	memcpy(ssif_info->data + 1, data, len);
1041	ssif_info->data_len = len;
1042	start_resend(ssif_info);
1043	return 0;
1044}
1045
1046/* Must be called with the message lock held. */
1047static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1048{
1049	struct ipmi_smi_msg *msg;
1050	unsigned long oflags;
1051
1052 restart:
1053	if (!IS_SSIF_IDLE(ssif_info)) {
1054		ipmi_ssif_unlock_cond(ssif_info, flags);
1055		return;
1056	}
1057
1058	if (!ssif_info->waiting_msg) {
1059		ssif_info->curr_msg = NULL;
1060		ipmi_ssif_unlock_cond(ssif_info, flags);
1061	} else {
1062		int rv;
1063
1064		ssif_info->curr_msg = ssif_info->waiting_msg;
1065		ssif_info->waiting_msg = NULL;
1066		ipmi_ssif_unlock_cond(ssif_info, flags);
1067		rv = start_send(ssif_info,
1068				ssif_info->curr_msg->data,
1069				ssif_info->curr_msg->data_size);
1070		if (rv) {
1071			msg = ssif_info->curr_msg;
1072			ssif_info->curr_msg = NULL;
1073			return_hosed_msg(ssif_info, msg);
1074			flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1075			goto restart;
1076		}
1077	}
1078}
1079
1080static void sender(void                *send_info,
1081		   struct ipmi_smi_msg *msg)
1082{
1083	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1084	unsigned long oflags, *flags;
1085
1086	BUG_ON(ssif_info->waiting_msg);
1087	ssif_info->waiting_msg = msg;
1088
1089	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1090	start_next_msg(ssif_info, flags);
1091
1092	if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1093		struct timespec64 t;
1094
1095		ktime_get_real_ts64(&t);
1096		dev_dbg(&ssif_info->client->dev,
1097			"**Enqueue %02x %02x: %lld.%6.6ld\n",
1098			msg->data[0], msg->data[1],
1099			(long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1100	}
1101}
1102
1103static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1104{
1105	struct ssif_info *ssif_info = send_info;
1106
1107	data->addr_src = ssif_info->addr_source;
1108	data->dev = &ssif_info->client->dev;
1109	data->addr_info = ssif_info->addr_info;
1110	get_device(data->dev);
1111
1112	return 0;
1113}
1114
1115/*
1116 * Upper layer wants us to request events.
1117 */
1118static void request_events(void *send_info)
1119{
1120	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1121	unsigned long oflags, *flags;
1122
1123	if (!ssif_info->has_event_buffer)
1124		return;
1125
1126	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1127	ssif_info->req_events = true;
1128	ipmi_ssif_unlock_cond(ssif_info, flags);
1129}
1130
1131/*
1132 * Upper layer is changing the flag saying whether we need to request
1133 * flags periodically or not.
1134 */
1135static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
1136{
1137	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1138	unsigned long oflags, *flags;
1139	long timeout = 0;
1140
1141	if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
1142		timeout = SSIF_WATCH_MSG_TIMEOUT;
1143	else if (watch_mask)
1144		timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
1145
1146	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1147	if (timeout != ssif_info->watch_timeout) {
1148		ssif_info->watch_timeout = timeout;
1149		if (ssif_info->watch_timeout)
1150			mod_timer(&ssif_info->watch_timer,
1151				  jiffies + ssif_info->watch_timeout);
1152	}
1153	ipmi_ssif_unlock_cond(ssif_info, flags);
1154}
1155
1156static int ssif_start_processing(void            *send_info,
1157				 struct ipmi_smi *intf)
1158{
1159	struct ssif_info *ssif_info = send_info;
1160
1161	ssif_info->intf = intf;
1162
1163	return 0;
1164}
1165
1166#define MAX_SSIF_BMCS 4
1167
1168static unsigned short addr[MAX_SSIF_BMCS];
1169static int num_addrs;
1170module_param_array(addr, ushort, &num_addrs, 0);
1171MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1172
1173static char *adapter_name[MAX_SSIF_BMCS];
1174static int num_adapter_names;
1175module_param_array(adapter_name, charp, &num_adapter_names, 0);
1176MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1177
1178static int slave_addrs[MAX_SSIF_BMCS];
1179static int num_slave_addrs;
1180module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1181MODULE_PARM_DESC(slave_addrs,
1182		 "The default IPMB slave address for the controller.");
1183
1184static bool alerts_broken;
1185module_param(alerts_broken, bool, 0);
1186MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1187
1188/*
1189 * Bit 0 enables message debugging, bit 1 enables state debugging, and
1190 * bit 2 enables timing debugging.  This is an array indexed by
1191 * interface number"
1192 */
1193static int dbg[MAX_SSIF_BMCS];
1194static int num_dbg;
1195module_param_array(dbg, int, &num_dbg, 0);
1196MODULE_PARM_DESC(dbg, "Turn on debugging.");
1197
1198static bool ssif_dbg_probe;
1199module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1200MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1201
1202static bool ssif_tryacpi = true;
1203module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1204MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1205
1206static bool ssif_trydmi = true;
1207module_param_named(trydmi, ssif_trydmi, bool, 0);
1208MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1209
1210static DEFINE_MUTEX(ssif_infos_mutex);
1211static LIST_HEAD(ssif_infos);
1212
1213#define IPMI_SSIF_ATTR(name) \
1214static ssize_t ipmi_##name##_show(struct device *dev,			\
1215				  struct device_attribute *attr,	\
1216				  char *buf)				\
1217{									\
1218	struct ssif_info *ssif_info = dev_get_drvdata(dev);		\
1219									\
1220	return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1221}									\
1222static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1223
1224static ssize_t ipmi_type_show(struct device *dev,
1225			      struct device_attribute *attr,
1226			      char *buf)
1227{
1228	return snprintf(buf, 10, "ssif\n");
1229}
1230static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1231
1232IPMI_SSIF_ATTR(sent_messages);
1233IPMI_SSIF_ATTR(sent_messages_parts);
1234IPMI_SSIF_ATTR(send_retries);
1235IPMI_SSIF_ATTR(send_errors);
1236IPMI_SSIF_ATTR(received_messages);
1237IPMI_SSIF_ATTR(received_message_parts);
1238IPMI_SSIF_ATTR(receive_retries);
1239IPMI_SSIF_ATTR(receive_errors);
1240IPMI_SSIF_ATTR(flag_fetches);
1241IPMI_SSIF_ATTR(hosed);
1242IPMI_SSIF_ATTR(events);
1243IPMI_SSIF_ATTR(watchdog_pretimeouts);
1244IPMI_SSIF_ATTR(alerts);
1245
1246static struct attribute *ipmi_ssif_dev_attrs[] = {
1247	&dev_attr_type.attr,
1248	&dev_attr_sent_messages.attr,
1249	&dev_attr_sent_messages_parts.attr,
1250	&dev_attr_send_retries.attr,
1251	&dev_attr_send_errors.attr,
1252	&dev_attr_received_messages.attr,
1253	&dev_attr_received_message_parts.attr,
1254	&dev_attr_receive_retries.attr,
1255	&dev_attr_receive_errors.attr,
1256	&dev_attr_flag_fetches.attr,
1257	&dev_attr_hosed.attr,
1258	&dev_attr_events.attr,
1259	&dev_attr_watchdog_pretimeouts.attr,
1260	&dev_attr_alerts.attr,
1261	NULL
1262};
1263
1264static const struct attribute_group ipmi_ssif_dev_attr_group = {
1265	.attrs		= ipmi_ssif_dev_attrs,
1266};
1267
1268static void shutdown_ssif(void *send_info)
1269{
1270	struct ssif_info *ssif_info = send_info;
1271
1272	device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1273	dev_set_drvdata(&ssif_info->client->dev, NULL);
1274
1275	/* make sure the driver is not looking for flags any more. */
1276	while (ssif_info->ssif_state != SSIF_IDLE)
1277		schedule_timeout(1);
1278
1279	ssif_info->stopping = true;
1280	del_timer_sync(&ssif_info->watch_timer);
1281	del_timer_sync(&ssif_info->retry_timer);
1282	if (ssif_info->thread) {
1283		complete(&ssif_info->wake_thread);
1284		kthread_stop(ssif_info->thread);
1285	}
1286}
1287
1288static int ssif_remove(struct i2c_client *client)
1289{
1290	struct ssif_info *ssif_info = i2c_get_clientdata(client);
1291	struct ssif_addr_info *addr_info;
1292
1293	if (!ssif_info)
1294		return 0;
1295
1296	/*
1297	 * After this point, we won't deliver anything asychronously
1298	 * to the message handler.  We can unregister ourself.
1299	 */
1300	ipmi_unregister_smi(ssif_info->intf);
1301
1302	list_for_each_entry(addr_info, &ssif_infos, link) {
1303		if (addr_info->client == client) {
1304			addr_info->client = NULL;
1305			break;
1306		}
1307	}
1308
1309	kfree(ssif_info);
1310
1311	return 0;
1312}
1313
1314static int read_response(struct i2c_client *client, unsigned char *resp)
1315{
1316	int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1317
1318	while (retry_cnt > 0) {
1319		ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1320						resp);
1321		if (ret > 0)
1322			break;
1323		msleep(SSIF_MSG_MSEC);
1324		retry_cnt--;
1325		if (retry_cnt <= 0)
1326			break;
1327	}
1328
1329	return ret;
1330}
1331
1332static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1333		  int *resp_len, unsigned char *resp)
1334{
1335	int retry_cnt;
1336	int ret;
1337
1338	retry_cnt = SSIF_SEND_RETRIES;
1339 retry1:
1340	ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1341	if (ret) {
1342		retry_cnt--;
1343		if (retry_cnt > 0) {
1344			msleep(SSIF_REQ_RETRY_MSEC);
1345			goto retry1;
1346		}
1347		return -ENODEV;
1348	}
1349
1350	ret = read_response(client, resp);
1351	if (ret > 0) {
1352		/* Validate that the response is correct. */
1353		if (ret < 3 ||
1354		    (resp[0] != (msg[0] | (1 << 2))) ||
1355		    (resp[1] != msg[1]))
1356			ret = -EINVAL;
1357		else if (ret > IPMI_MAX_MSG_LENGTH) {
1358			ret = -E2BIG;
1359		} else {
1360			*resp_len = ret;
1361			ret = 0;
1362		}
1363	}
1364
1365	return ret;
1366}
1367
1368static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1369{
1370	unsigned char *resp;
1371	unsigned char msg[3];
1372	int           rv;
1373	int           len;
1374
1375	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1376	if (!resp)
1377		return -ENOMEM;
1378
1379	/* Do a Get Device ID command, since it is required. */
1380	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1381	msg[1] = IPMI_GET_DEVICE_ID_CMD;
1382	rv = do_cmd(client, 2, msg, &len, resp);
1383	if (rv)
1384		rv = -ENODEV;
1385	else
1386		strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1387	kfree(resp);
1388	return rv;
1389}
1390
1391static int strcmp_nospace(char *s1, char *s2)
1392{
1393	while (*s1 && *s2) {
1394		while (isspace(*s1))
1395			s1++;
1396		while (isspace(*s2))
1397			s2++;
1398		if (*s1 > *s2)
1399			return 1;
1400		if (*s1 < *s2)
1401			return -1;
1402		s1++;
1403		s2++;
1404	}
1405	return 0;
1406}
1407
1408static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1409					     char *adapter_name,
1410					     bool match_null_name)
1411{
1412	struct ssif_addr_info *info, *found = NULL;
1413
1414restart:
1415	list_for_each_entry(info, &ssif_infos, link) {
1416		if (info->binfo.addr == addr) {
1417			if (info->addr_src == SI_SMBIOS && !info->adapter_name)
1418				info->adapter_name = kstrdup(adapter_name,
1419							     GFP_KERNEL);
1420
1421			if (info->adapter_name || adapter_name) {
1422				if (!info->adapter_name != !adapter_name) {
1423					/* One is NULL and one is not */
1424					continue;
1425				}
1426				if (adapter_name &&
1427				    strcmp_nospace(info->adapter_name,
1428						   adapter_name))
1429					/* Names do not match */
1430					continue;
1431			}
1432			found = info;
1433			break;
1434		}
1435	}
1436
1437	if (!found && match_null_name) {
1438		/* Try to get an exact match first, then try with a NULL name */
1439		adapter_name = NULL;
1440		match_null_name = false;
1441		goto restart;
1442	}
1443
1444	return found;
1445}
1446
1447static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1448{
1449#ifdef CONFIG_ACPI
1450	acpi_handle acpi_handle;
1451
1452	acpi_handle = ACPI_HANDLE(dev);
1453	if (acpi_handle) {
1454		ssif_info->addr_source = SI_ACPI;
1455		ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1456		request_module("acpi_ipmi");
1457		return true;
1458	}
1459#endif
1460	return false;
1461}
1462
1463static int find_slave_address(struct i2c_client *client, int slave_addr)
1464{
1465#ifdef CONFIG_IPMI_DMI_DECODE
1466	if (!slave_addr)
1467		slave_addr = ipmi_dmi_get_slave_addr(
1468			SI_TYPE_INVALID,
1469			i2c_adapter_id(client->adapter),
1470			client->addr);
1471#endif
1472
1473	return slave_addr;
1474}
1475
1476static int start_multipart_test(struct i2c_client *client,
1477				unsigned char *msg, bool do_middle)
1478{
1479	int retry_cnt = SSIF_SEND_RETRIES, ret;
1480
1481retry_write:
1482	ret = i2c_smbus_write_block_data(client,
1483					 SSIF_IPMI_MULTI_PART_REQUEST_START,
1484					 32, msg);
1485	if (ret) {
1486		retry_cnt--;
1487		if (retry_cnt > 0) {
1488			msleep(SSIF_REQ_RETRY_MSEC);
1489			goto retry_write;
1490		}
1491		dev_err(&client->dev, "Could not write multi-part start, though the BMC said it could handle it.  Just limit sends to one part.\n");
1492		return ret;
1493	}
1494
1495	if (!do_middle)
1496		return 0;
1497
1498	ret = i2c_smbus_write_block_data(client,
1499					 SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1500					 32, msg + 32);
1501	if (ret) {
1502		dev_err(&client->dev, "Could not write multi-part middle, though the BMC said it could handle it.  Just limit sends to one part.\n");
1503		return ret;
1504	}
1505
1506	return 0;
1507}
1508
1509static void test_multipart_messages(struct i2c_client *client,
1510				    struct ssif_info *ssif_info,
1511				    unsigned char *resp)
1512{
1513	unsigned char msg[65];
1514	int ret;
1515	bool do_middle;
1516
1517	if (ssif_info->max_xmit_msg_size <= 32)
1518		return;
1519
1520	do_middle = ssif_info->max_xmit_msg_size > 63;
1521
1522	memset(msg, 0, sizeof(msg));
1523	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1524	msg[1] = IPMI_GET_DEVICE_ID_CMD;
1525
1526	/*
1527	 * The specification is all messed up dealing with sending
1528	 * multi-part messages.  Per what the specification says, it
1529	 * is impossible to send a message that is a multiple of 32
1530	 * bytes, except for 32 itself.  It talks about a "start"
1531	 * transaction (cmd=6) that must be 32 bytes, "middle"
1532	 * transaction (cmd=7) that must be 32 bytes, and an "end"
1533	 * transaction.  The "end" transaction is shown as cmd=7 in
1534	 * the text, but if that's the case there is no way to
1535	 * differentiate between a middle and end part except the
1536	 * length being less than 32.  But there is a table at the far
1537	 * end of the section (that I had never noticed until someone
1538	 * pointed it out to me) that mentions it as cmd=8.
1539	 *
1540	 * After some thought, I think the example is wrong and the
1541	 * end transaction should be cmd=8.  But some systems don't
1542	 * implement cmd=8, they use a zero-length end transaction,
1543	 * even though that violates the SMBus specification.
1544	 *
1545	 * So, to work around this, this code tests if cmd=8 works.
1546	 * If it does, then we use that.  If not, it tests zero-
1547	 * byte end transactions.  If that works, good.  If not,
1548	 * we only allow 63-byte transactions max.
1549	 */
1550
1551	ret = start_multipart_test(client, msg, do_middle);
1552	if (ret)
1553		goto out_no_multi_part;
1554
1555	ret = i2c_smbus_write_block_data(client,
1556					 SSIF_IPMI_MULTI_PART_REQUEST_END,
1557					 1, msg + 64);
1558
1559	if (!ret)
1560		ret = read_response(client, resp);
1561
1562	if (ret > 0) {
1563		/* End transactions work, we are good. */
1564		ssif_info->cmd8_works = true;
1565		return;
1566	}
1567
1568	ret = start_multipart_test(client, msg, do_middle);
1569	if (ret) {
1570		dev_err(&client->dev, "Second multipart test failed.\n");
1571		goto out_no_multi_part;
1572	}
1573
1574	ret = i2c_smbus_write_block_data(client,
1575					 SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1576					 0, msg + 64);
1577	if (!ret)
1578		ret = read_response(client, resp);
1579	if (ret > 0)
1580		/* Zero-size end parts work, use those. */
1581		return;
1582
1583	/* Limit to 63 bytes and use a short middle command to mark the end. */
1584	if (ssif_info->max_xmit_msg_size > 63)
1585		ssif_info->max_xmit_msg_size = 63;
1586	return;
1587
1588out_no_multi_part:
1589	ssif_info->max_xmit_msg_size = 32;
1590	return;
1591}
1592
1593/*
1594 * Global enables we care about.
1595 */
1596#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1597			     IPMI_BMC_EVT_MSG_INTR)
1598
1599static void ssif_remove_dup(struct i2c_client *client)
1600{
1601	struct ssif_info *ssif_info = i2c_get_clientdata(client);
1602
1603	ipmi_unregister_smi(ssif_info->intf);
1604	kfree(ssif_info);
1605}
1606
1607static int ssif_add_infos(struct i2c_client *client)
1608{
1609	struct ssif_addr_info *info;
1610
1611	info = kzalloc(sizeof(*info), GFP_KERNEL);
1612	if (!info)
1613		return -ENOMEM;
1614	info->addr_src = SI_ACPI;
1615	info->client = client;
1616	info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL);
1617	if (!info->adapter_name) {
1618		kfree(info);
1619		return -ENOMEM;
1620	}
1621
1622	info->binfo.addr = client->addr;
1623	list_add_tail(&info->link, &ssif_infos);
1624	return 0;
1625}
1626
1627/*
1628 * Prefer ACPI over SMBIOS, if both are available.
1629 * So if we get an ACPI interface and have already registered a SMBIOS
1630 * interface at the same address, remove the SMBIOS and add the ACPI one.
1631 */
1632static int ssif_check_and_remove(struct i2c_client *client,
1633			      struct ssif_info *ssif_info)
1634{
1635	struct ssif_addr_info *info;
1636
1637	list_for_each_entry(info, &ssif_infos, link) {
1638		if (!info->client)
1639			return 0;
1640		if (!strcmp(info->adapter_name, client->adapter->name) &&
1641		    info->binfo.addr == client->addr) {
1642			if (info->addr_src == SI_ACPI)
1643				return -EEXIST;
1644
1645			if (ssif_info->addr_source == SI_ACPI &&
1646			    info->addr_src == SI_SMBIOS) {
1647				dev_info(&client->dev,
1648					 "Removing %s-specified SSIF interface in favor of ACPI\n",
1649					 ipmi_addr_src_to_str(info->addr_src));
1650				ssif_remove_dup(info->client);
1651				return 0;
1652			}
1653		}
1654	}
1655	return 0;
1656}
1657
1658static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1659{
1660	unsigned char     msg[3];
1661	unsigned char     *resp;
1662	struct ssif_info   *ssif_info;
1663	int               rv = 0;
1664	int               len;
1665	int               i;
1666	u8		  slave_addr = 0;
1667	struct ssif_addr_info *addr_info = NULL;
1668
1669	mutex_lock(&ssif_infos_mutex);
1670	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1671	if (!resp) {
1672		mutex_unlock(&ssif_infos_mutex);
1673		return -ENOMEM;
1674	}
1675
1676	ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1677	if (!ssif_info) {
1678		kfree(resp);
1679		mutex_unlock(&ssif_infos_mutex);
1680		return -ENOMEM;
1681	}
1682
1683	if (!check_acpi(ssif_info, &client->dev)) {
1684		addr_info = ssif_info_find(client->addr, client->adapter->name,
1685					   true);
1686		if (!addr_info) {
1687			/* Must have come in through sysfs. */
1688			ssif_info->addr_source = SI_HOTMOD;
1689		} else {
1690			ssif_info->addr_source = addr_info->addr_src;
1691			ssif_info->ssif_debug = addr_info->debug;
1692			ssif_info->addr_info = addr_info->addr_info;
1693			addr_info->client = client;
1694			slave_addr = addr_info->slave_addr;
1695		}
1696	}
1697
1698	ssif_info->client = client;
1699	i2c_set_clientdata(client, ssif_info);
1700
1701	rv = ssif_check_and_remove(client, ssif_info);
1702	/* If rv is 0 and addr source is not SI_ACPI, continue probing */
1703	if (!rv && ssif_info->addr_source == SI_ACPI) {
1704		rv = ssif_add_infos(client);
1705		if (rv) {
1706			dev_err(&client->dev, "Out of memory!, exiting ..\n");
1707			goto out;
1708		}
1709	} else if (rv) {
1710		dev_err(&client->dev, "Not probing, Interface already present\n");
1711		goto out;
1712	}
1713
1714	slave_addr = find_slave_address(client, slave_addr);
1715
1716	dev_info(&client->dev,
1717		 "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1718		ipmi_addr_src_to_str(ssif_info->addr_source),
1719		client->addr, client->adapter->name, slave_addr);
1720
1721	/* Now check for system interface capabilities */
1722	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1723	msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1724	msg[2] = 0; /* SSIF */
1725	rv = do_cmd(client, 3, msg, &len, resp);
1726	if (!rv && (len >= 3) && (resp[2] == 0)) {
1727		if (len < 7) {
1728			if (ssif_dbg_probe)
1729				dev_dbg(&ssif_info->client->dev,
1730					"SSIF info too short: %d\n", len);
1731			goto no_support;
1732		}
1733
1734		/* Got a good SSIF response, handle it. */
1735		ssif_info->max_xmit_msg_size = resp[5];
1736		ssif_info->max_recv_msg_size = resp[6];
1737		ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1738		ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1739
1740		/* Sanitize the data */
1741		switch (ssif_info->multi_support) {
1742		case SSIF_NO_MULTI:
1743			if (ssif_info->max_xmit_msg_size > 32)
1744				ssif_info->max_xmit_msg_size = 32;
1745			if (ssif_info->max_recv_msg_size > 32)
1746				ssif_info->max_recv_msg_size = 32;
1747			break;
1748
1749		case SSIF_MULTI_2_PART:
1750			if (ssif_info->max_xmit_msg_size > 63)
1751				ssif_info->max_xmit_msg_size = 63;
1752			if (ssif_info->max_recv_msg_size > 62)
1753				ssif_info->max_recv_msg_size = 62;
1754			break;
1755
1756		case SSIF_MULTI_n_PART:
1757			/* We take whatever size given, but do some testing. */
1758			break;
1759
1760		default:
1761			/* Data is not sane, just give up. */
1762			goto no_support;
1763		}
1764	} else {
1765 no_support:
1766		/* Assume no multi-part or PEC support */
1767		dev_info(&ssif_info->client->dev,
1768			 "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1769			rv, len, resp[2]);
1770
1771		ssif_info->max_xmit_msg_size = 32;
1772		ssif_info->max_recv_msg_size = 32;
1773		ssif_info->multi_support = SSIF_NO_MULTI;
1774		ssif_info->supports_pec = 0;
1775	}
1776
1777	test_multipart_messages(client, ssif_info, resp);
1778
1779	/* Make sure the NMI timeout is cleared. */
1780	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1781	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1782	msg[2] = WDT_PRE_TIMEOUT_INT;
1783	rv = do_cmd(client, 3, msg, &len, resp);
1784	if (rv || (len < 3) || (resp[2] != 0))
1785		dev_warn(&ssif_info->client->dev,
1786			 "Unable to clear message flags: %d %d %2.2x\n",
1787			 rv, len, resp[2]);
1788
1789	/* Attempt to enable the event buffer. */
1790	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1791	msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1792	rv = do_cmd(client, 2, msg, &len, resp);
1793	if (rv || (len < 4) || (resp[2] != 0)) {
1794		dev_warn(&ssif_info->client->dev,
1795			 "Error getting global enables: %d %d %2.2x\n",
1796			 rv, len, resp[2]);
1797		rv = 0; /* Not fatal */
1798		goto found;
1799	}
1800
1801	ssif_info->global_enables = resp[3];
1802
1803	if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1804		ssif_info->has_event_buffer = true;
1805		/* buffer is already enabled, nothing to do. */
1806		goto found;
1807	}
1808
1809	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1810	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1811	msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1812	rv = do_cmd(client, 3, msg, &len, resp);
1813	if (rv || (len < 2)) {
1814		dev_warn(&ssif_info->client->dev,
1815			 "Error setting global enables: %d %d %2.2x\n",
1816			 rv, len, resp[2]);
1817		rv = 0; /* Not fatal */
1818		goto found;
1819	}
1820
1821	if (resp[2] == 0) {
1822		/* A successful return means the event buffer is supported. */
1823		ssif_info->has_event_buffer = true;
1824		ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1825	}
1826
1827	/* Some systems don't behave well if you enable alerts. */
1828	if (alerts_broken)
1829		goto found;
1830
1831	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1832	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1833	msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1834	rv = do_cmd(client, 3, msg, &len, resp);
1835	if (rv || (len < 2)) {
1836		dev_warn(&ssif_info->client->dev,
1837			 "Error setting global enables: %d %d %2.2x\n",
1838			 rv, len, resp[2]);
1839		rv = 0; /* Not fatal */
1840		goto found;
1841	}
1842
1843	if (resp[2] == 0) {
1844		/* A successful return means the alert is supported. */
1845		ssif_info->supports_alert = true;
1846		ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1847	}
1848
1849 found:
1850	if (ssif_dbg_probe) {
1851		dev_dbg(&ssif_info->client->dev,
1852		       "%s: i2c_probe found device at i2c address %x\n",
1853		       __func__, client->addr);
1854	}
1855
1856	spin_lock_init(&ssif_info->lock);
1857	ssif_info->ssif_state = SSIF_IDLE;
1858	timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1859	timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1860
1861	for (i = 0; i < SSIF_NUM_STATS; i++)
1862		atomic_set(&ssif_info->stats[i], 0);
1863
1864	if (ssif_info->supports_pec)
1865		ssif_info->client->flags |= I2C_CLIENT_PEC;
1866
1867	ssif_info->handlers.owner = THIS_MODULE;
1868	ssif_info->handlers.start_processing = ssif_start_processing;
1869	ssif_info->handlers.shutdown = shutdown_ssif;
1870	ssif_info->handlers.get_smi_info = get_smi_info;
1871	ssif_info->handlers.sender = sender;
1872	ssif_info->handlers.request_events = request_events;
1873	ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1874
1875	{
1876		unsigned int thread_num;
1877
1878		thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1879			       << 8) |
1880			      ssif_info->client->addr);
1881		init_completion(&ssif_info->wake_thread);
1882		ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1883					       "kssif%4.4x", thread_num);
1884		if (IS_ERR(ssif_info->thread)) {
1885			rv = PTR_ERR(ssif_info->thread);
1886			dev_notice(&ssif_info->client->dev,
1887				   "Could not start kernel thread: error %d\n",
1888				   rv);
1889			goto out;
1890		}
1891	}
1892
1893	dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1894	rv = device_add_group(&ssif_info->client->dev,
1895			      &ipmi_ssif_dev_attr_group);
1896	if (rv) {
1897		dev_err(&ssif_info->client->dev,
1898			"Unable to add device attributes: error %d\n",
1899			rv);
1900		goto out;
1901	}
1902
1903	rv = ipmi_register_smi(&ssif_info->handlers,
1904			       ssif_info,
1905			       &ssif_info->client->dev,
1906			       slave_addr);
1907	if (rv) {
1908		dev_err(&ssif_info->client->dev,
1909			"Unable to register device: error %d\n", rv);
1910		goto out_remove_attr;
1911	}
1912
1913 out:
1914	if (rv) {
1915		if (addr_info)
1916			addr_info->client = NULL;
1917
1918		dev_err(&ssif_info->client->dev,
1919			"Unable to start IPMI SSIF: %d\n", rv);
1920		i2c_set_clientdata(client, NULL);
1921		kfree(ssif_info);
1922	}
1923	kfree(resp);
1924	mutex_unlock(&ssif_infos_mutex);
1925	return rv;
1926
1927out_remove_attr:
1928	device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1929	dev_set_drvdata(&ssif_info->client->dev, NULL);
1930	goto out;
1931}
1932
1933static int new_ssif_client(int addr, char *adapter_name,
1934			   int debug, int slave_addr,
1935			   enum ipmi_addr_src addr_src,
1936			   struct device *dev)
1937{
1938	struct ssif_addr_info *addr_info;
1939	int rv = 0;
1940
1941	mutex_lock(&ssif_infos_mutex);
1942	if (ssif_info_find(addr, adapter_name, false)) {
1943		rv = -EEXIST;
1944		goto out_unlock;
1945	}
1946
1947	addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1948	if (!addr_info) {
1949		rv = -ENOMEM;
1950		goto out_unlock;
1951	}
1952
1953	if (adapter_name) {
1954		addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1955		if (!addr_info->adapter_name) {
1956			kfree(addr_info);
1957			rv = -ENOMEM;
1958			goto out_unlock;
1959		}
1960	}
1961
1962	strncpy(addr_info->binfo.type, DEVICE_NAME,
1963		sizeof(addr_info->binfo.type));
1964	addr_info->binfo.addr = addr;
1965	addr_info->binfo.platform_data = addr_info;
1966	addr_info->debug = debug;
1967	addr_info->slave_addr = slave_addr;
1968	addr_info->addr_src = addr_src;
1969	addr_info->dev = dev;
1970
1971	if (dev)
1972		dev_set_drvdata(dev, addr_info);
1973
1974	list_add_tail(&addr_info->link, &ssif_infos);
1975
1976	/* Address list will get it */
1977
1978out_unlock:
1979	mutex_unlock(&ssif_infos_mutex);
1980	return rv;
1981}
1982
1983static void free_ssif_clients(void)
1984{
1985	struct ssif_addr_info *info, *tmp;
1986
1987	mutex_lock(&ssif_infos_mutex);
1988	list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1989		list_del(&info->link);
1990		kfree(info->adapter_name);
1991		kfree(info);
1992	}
1993	mutex_unlock(&ssif_infos_mutex);
1994}
1995
1996static unsigned short *ssif_address_list(void)
1997{
1998	struct ssif_addr_info *info;
1999	unsigned int count = 0, i = 0;
2000	unsigned short *address_list;
2001
2002	list_for_each_entry(info, &ssif_infos, link)
2003		count++;
2004
2005	address_list = kcalloc(count + 1, sizeof(*address_list),
2006			       GFP_KERNEL);
2007	if (!address_list)
2008		return NULL;
2009
2010	list_for_each_entry(info, &ssif_infos, link) {
2011		unsigned short addr = info->binfo.addr;
2012		int j;
2013
2014		for (j = 0; j < i; j++) {
2015			if (address_list[j] == addr)
2016				/* Found a dup. */
2017				break;
2018		}
2019		if (j == i) /* Didn't find it in the list. */
2020			address_list[i++] = addr;
2021	}
2022	address_list[i] = I2C_CLIENT_END;
2023
2024	return address_list;
2025}
2026
2027#ifdef CONFIG_ACPI
2028static const struct acpi_device_id ssif_acpi_match[] = {
2029	{ "IPI0001", 0 },
2030	{ },
2031};
2032MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
2033#endif
2034
2035#ifdef CONFIG_DMI
2036static int dmi_ipmi_probe(struct platform_device *pdev)
2037{
2038	u8 slave_addr = 0;
2039	u16 i2c_addr;
2040	int rv;
2041
2042	if (!ssif_trydmi)
2043		return -ENODEV;
2044
2045	rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
2046	if (rv) {
2047		dev_warn(&pdev->dev, "No i2c-addr property\n");
2048		return -ENODEV;
2049	}
2050
2051	rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
2052	if (rv)
2053		slave_addr = 0x20;
2054
2055	return new_ssif_client(i2c_addr, NULL, 0,
2056			       slave_addr, SI_SMBIOS, &pdev->dev);
2057}
2058#else
2059static int dmi_ipmi_probe(struct platform_device *pdev)
2060{
2061	return -ENODEV;
2062}
2063#endif
2064
2065static const struct i2c_device_id ssif_id[] = {
2066	{ DEVICE_NAME, 0 },
2067	{ }
2068};
2069MODULE_DEVICE_TABLE(i2c, ssif_id);
2070
2071static struct i2c_driver ssif_i2c_driver = {
2072	.class		= I2C_CLASS_HWMON,
2073	.driver		= {
2074		.name			= DEVICE_NAME
2075	},
2076	.probe		= ssif_probe,
2077	.remove		= ssif_remove,
2078	.alert		= ssif_alert,
2079	.id_table	= ssif_id,
2080	.detect		= ssif_detect
2081};
2082
2083static int ssif_platform_probe(struct platform_device *dev)
2084{
2085	return dmi_ipmi_probe(dev);
2086}
2087
2088static int ssif_platform_remove(struct platform_device *dev)
2089{
2090	struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
2091
2092	if (!addr_info)
2093		return 0;
2094
2095	mutex_lock(&ssif_infos_mutex);
2096	list_del(&addr_info->link);
2097	kfree(addr_info);
2098	mutex_unlock(&ssif_infos_mutex);
2099	return 0;
2100}
2101
2102static const struct platform_device_id ssif_plat_ids[] = {
2103    { "dmi-ipmi-ssif", 0 },
2104    { }
2105};
2106
2107static struct platform_driver ipmi_driver = {
2108	.driver = {
2109		.name = DEVICE_NAME,
2110	},
2111	.probe		= ssif_platform_probe,
2112	.remove		= ssif_platform_remove,
2113	.id_table       = ssif_plat_ids
2114};
2115
2116static int init_ipmi_ssif(void)
2117{
2118	int i;
2119	int rv;
2120
2121	if (initialized)
2122		return 0;
2123
2124	pr_info("IPMI SSIF Interface driver\n");
2125
2126	/* build list for i2c from addr list */
2127	for (i = 0; i < num_addrs; i++) {
2128		rv = new_ssif_client(addr[i], adapter_name[i],
2129				     dbg[i], slave_addrs[i],
2130				     SI_HARDCODED, NULL);
2131		if (rv)
2132			pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2133			       addr[i]);
2134	}
2135
2136	if (ssif_tryacpi)
2137		ssif_i2c_driver.driver.acpi_match_table	=
2138			ACPI_PTR(ssif_acpi_match);
2139
2140	if (ssif_trydmi) {
2141		rv = platform_driver_register(&ipmi_driver);
2142		if (rv)
2143			pr_err("Unable to register driver: %d\n", rv);
2144		else
2145			platform_registered = true;
2146	}
2147
2148	ssif_i2c_driver.address_list = ssif_address_list();
2149
2150	rv = i2c_add_driver(&ssif_i2c_driver);
2151	if (!rv)
2152		initialized = true;
2153
2154	return rv;
2155}
2156module_init(init_ipmi_ssif);
2157
2158static void cleanup_ipmi_ssif(void)
2159{
2160	if (!initialized)
2161		return;
2162
2163	initialized = false;
2164
2165	i2c_del_driver(&ssif_i2c_driver);
2166
2167	kfree(ssif_i2c_driver.address_list);
2168
2169	if (ssif_trydmi && platform_registered)
2170		platform_driver_unregister(&ipmi_driver);
2171
2172	free_ssif_clients();
2173}
2174module_exit(cleanup_ipmi_ssif);
2175
2176MODULE_ALIAS("platform:dmi-ipmi-ssif");
2177MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2178MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2179MODULE_LICENSE("GPL");
2180