xref: /openbmc/linux/drivers/misc/mei/mei_dev.h (revision bc5aa3a0)
1 /*
2  *
3  * Intel Management Engine Interface (Intel MEI) Linux driver
4  * Copyright (c) 2003-2012, Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  */
16 
17 #ifndef _MEI_DEV_H_
18 #define _MEI_DEV_H_
19 
20 #include <linux/types.h>
21 #include <linux/cdev.h>
22 #include <linux/poll.h>
23 #include <linux/mei.h>
24 #include <linux/mei_cl_bus.h>
25 
26 #include "hw.h"
27 #include "hbm.h"
28 
29 
30 /*
31  * AMTHI Client UUID
32  */
33 extern const uuid_le mei_amthif_guid;
34 
35 #define MEI_RD_MSG_BUF_SIZE           (128 * sizeof(u32))
36 
37 /*
38  * Number of Maximum MEI Clients
39  */
40 #define MEI_CLIENTS_MAX 256
41 
42 /*
43  * maximum number of consecutive resets
44  */
45 #define MEI_MAX_CONSEC_RESET  3
46 
47 /*
48  * Number of File descriptors/handles
49  * that can be opened to the driver.
50  *
51  * Limit to 255: 256 Total Clients
52  * minus internal client for MEI Bus Messages
53  */
54 #define  MEI_MAX_OPEN_HANDLE_COUNT (MEI_CLIENTS_MAX - 1)
55 
56 /* File state */
57 enum file_state {
58 	MEI_FILE_INITIALIZING = 0,
59 	MEI_FILE_CONNECTING,
60 	MEI_FILE_CONNECTED,
61 	MEI_FILE_DISCONNECTING,
62 	MEI_FILE_DISCONNECT_REPLY,
63 	MEI_FILE_DISCONNECT_REQUIRED,
64 	MEI_FILE_DISCONNECTED,
65 };
66 
67 /* MEI device states */
68 enum mei_dev_state {
69 	MEI_DEV_INITIALIZING = 0,
70 	MEI_DEV_INIT_CLIENTS,
71 	MEI_DEV_ENABLED,
72 	MEI_DEV_RESETTING,
73 	MEI_DEV_DISABLED,
74 	MEI_DEV_POWER_DOWN,
75 	MEI_DEV_POWER_UP
76 };
77 
78 const char *mei_dev_state_str(int state);
79 
80 enum iamthif_states {
81 	MEI_IAMTHIF_IDLE,
82 	MEI_IAMTHIF_WRITING,
83 	MEI_IAMTHIF_FLOW_CONTROL,
84 	MEI_IAMTHIF_READING,
85 	MEI_IAMTHIF_READ_COMPLETE
86 };
87 
88 enum mei_file_transaction_states {
89 	MEI_IDLE,
90 	MEI_WRITING,
91 	MEI_WRITE_COMPLETE,
92 	MEI_FLOW_CONTROL,
93 	MEI_READING,
94 	MEI_READ_COMPLETE
95 };
96 
97 /**
98  * enum mei_cb_file_ops  - file operation associated with the callback
99  * @MEI_FOP_READ:       read
100  * @MEI_FOP_WRITE:      write
101  * @MEI_FOP_CONNECT:    connect
102  * @MEI_FOP_DISCONNECT: disconnect
103  * @MEI_FOP_DISCONNECT_RSP: disconnect response
104  * @MEI_FOP_NOTIFY_START:   start notification
105  * @MEI_FOP_NOTIFY_STOP:    stop notification
106  */
107 enum mei_cb_file_ops {
108 	MEI_FOP_READ = 0,
109 	MEI_FOP_WRITE,
110 	MEI_FOP_CONNECT,
111 	MEI_FOP_DISCONNECT,
112 	MEI_FOP_DISCONNECT_RSP,
113 	MEI_FOP_NOTIFY_START,
114 	MEI_FOP_NOTIFY_STOP,
115 };
116 
117 /*
118  * Intel MEI message data struct
119  */
120 struct mei_msg_data {
121 	size_t size;
122 	unsigned char *data;
123 };
124 
125 /* Maximum number of processed FW status registers */
126 #define MEI_FW_STATUS_MAX 6
127 /* Minimal  buffer for FW status string (8 bytes in dw + space or '\0') */
128 #define MEI_FW_STATUS_STR_SZ (MEI_FW_STATUS_MAX * (8 + 1))
129 
130 
131 /*
132  * struct mei_fw_status - storage of FW status data
133  *
134  * @count: number of actually available elements in array
135  * @status: FW status registers
136  */
137 struct mei_fw_status {
138 	int count;
139 	u32 status[MEI_FW_STATUS_MAX];
140 };
141 
142 /**
143  * struct mei_me_client - representation of me (fw) client
144  *
145  * @list: link in me client list
146  * @refcnt: struct reference count
147  * @props: client properties
148  * @client_id: me client id
149  * @mei_flow_ctrl_creds: flow control credits
150  * @connect_count: number connections to this client
151  * @bus_added: added to bus
152  */
153 struct mei_me_client {
154 	struct list_head list;
155 	struct kref refcnt;
156 	struct mei_client_properties props;
157 	u8 client_id;
158 	u8 mei_flow_ctrl_creds;
159 	u8 connect_count;
160 	u8 bus_added;
161 };
162 
163 
164 struct mei_cl;
165 
166 /**
167  * struct mei_cl_cb - file operation callback structure
168  *
169  * @list: link in callback queue
170  * @cl: file client who is running this operation
171  * @fop_type: file operation type
172  * @buf: buffer for data associated with the callback
173  * @buf_idx: last read index
174  * @fp: pointer to file structure
175  * @status: io status of the cb
176  * @internal: communication between driver and FW flag
177  * @completed: the transfer or reception has completed
178  */
179 struct mei_cl_cb {
180 	struct list_head list;
181 	struct mei_cl *cl;
182 	enum mei_cb_file_ops fop_type;
183 	struct mei_msg_data buf;
184 	size_t buf_idx;
185 	const struct file *fp;
186 	int status;
187 	u32 internal:1;
188 	u32 completed:1;
189 };
190 
191 /**
192  * struct mei_cl - me client host representation
193  *    carried in file->private_data
194  *
195  * @link: link in the clients list
196  * @dev: mei parent device
197  * @state: file operation state
198  * @tx_wait: wait queue for tx completion
199  * @rx_wait: wait queue for rx completion
200  * @wait:  wait queue for management operation
201  * @ev_wait: notification wait queue
202  * @ev_async: event async notification
203  * @status: connection status
204  * @me_cl: fw client connected
205  * @host_client_id: host id
206  * @mei_flow_ctrl_creds: transmit flow credentials
207  * @timer_count:  watchdog timer for operation completion
208  * @reserved: reserved for alignment
209  * @notify_en: notification - enabled/disabled
210  * @notify_ev: pending notification event
211  * @writing_state: state of the tx
212  * @rd_pending: pending read credits
213  * @rd_completed: completed read
214  *
215  * @cldev: device on the mei client bus
216  */
217 struct mei_cl {
218 	struct list_head link;
219 	struct mei_device *dev;
220 	enum file_state state;
221 	wait_queue_head_t tx_wait;
222 	wait_queue_head_t rx_wait;
223 	wait_queue_head_t wait;
224 	wait_queue_head_t ev_wait;
225 	struct fasync_struct *ev_async;
226 	int status;
227 	struct mei_me_client *me_cl;
228 	u8 host_client_id;
229 	u8 mei_flow_ctrl_creds;
230 	u8 timer_count;
231 	u8 reserved;
232 	u8 notify_en;
233 	u8 notify_ev;
234 	enum mei_file_transaction_states writing_state;
235 	struct list_head rd_pending;
236 	struct list_head rd_completed;
237 
238 	struct mei_cl_device *cldev;
239 };
240 
241 /**
242  * struct mei_hw_ops - hw specific ops
243  *
244  * @host_is_ready    : query for host readiness
245  *
246  * @hw_is_ready      : query if hw is ready
247  * @hw_reset         : reset hw
248  * @hw_start         : start hw after reset
249  * @hw_config        : configure hw
250  *
251  * @fw_status        : get fw status registers
252  * @pg_state         : power gating state of the device
253  * @pg_in_transition : is device now in pg transition
254  * @pg_is_enabled    : is power gating enabled
255  *
256  * @intr_clear       : clear pending interrupts
257  * @intr_enable      : enable interrupts
258  * @intr_disable     : disable interrupts
259  *
260  * @hbuf_free_slots  : query for write buffer empty slots
261  * @hbuf_is_ready    : query if write buffer is empty
262  * @hbuf_max_len     : query for write buffer max len
263  *
264  * @write            : write a message to FW
265  *
266  * @rdbuf_full_slots : query how many slots are filled
267  *
268  * @read_hdr         : get first 4 bytes (header)
269  * @read             : read a buffer from the FW
270  */
271 struct mei_hw_ops {
272 
273 	bool (*host_is_ready)(struct mei_device *dev);
274 
275 	bool (*hw_is_ready)(struct mei_device *dev);
276 	int (*hw_reset)(struct mei_device *dev, bool enable);
277 	int (*hw_start)(struct mei_device *dev);
278 	void (*hw_config)(struct mei_device *dev);
279 
280 
281 	int (*fw_status)(struct mei_device *dev, struct mei_fw_status *fw_sts);
282 	enum mei_pg_state (*pg_state)(struct mei_device *dev);
283 	bool (*pg_in_transition)(struct mei_device *dev);
284 	bool (*pg_is_enabled)(struct mei_device *dev);
285 
286 	void (*intr_clear)(struct mei_device *dev);
287 	void (*intr_enable)(struct mei_device *dev);
288 	void (*intr_disable)(struct mei_device *dev);
289 
290 	int (*hbuf_free_slots)(struct mei_device *dev);
291 	bool (*hbuf_is_ready)(struct mei_device *dev);
292 	size_t (*hbuf_max_len)(const struct mei_device *dev);
293 
294 	int (*write)(struct mei_device *dev,
295 		     struct mei_msg_hdr *hdr,
296 		     unsigned char *buf);
297 
298 	int (*rdbuf_full_slots)(struct mei_device *dev);
299 
300 	u32 (*read_hdr)(const struct mei_device *dev);
301 	int (*read)(struct mei_device *dev,
302 		     unsigned char *buf, unsigned long len);
303 };
304 
305 /* MEI bus API*/
306 void mei_cl_bus_rescan(struct mei_device *bus);
307 void mei_cl_bus_rescan_work(struct work_struct *work);
308 void mei_cl_bus_dev_fixup(struct mei_cl_device *dev);
309 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
310 			bool blocking);
311 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length);
312 bool mei_cl_bus_rx_event(struct mei_cl *cl);
313 bool mei_cl_bus_notify_event(struct mei_cl *cl);
314 void mei_cl_bus_remove_devices(struct mei_device *bus);
315 int mei_cl_bus_init(void);
316 void mei_cl_bus_exit(void);
317 
318 /**
319  * enum mei_pg_event - power gating transition events
320  *
321  * @MEI_PG_EVENT_IDLE: the driver is not in power gating transition
322  * @MEI_PG_EVENT_WAIT: the driver is waiting for a pg event to complete
323  * @MEI_PG_EVENT_RECEIVED: the driver received pg event
324  * @MEI_PG_EVENT_INTR_WAIT: the driver is waiting for a pg event interrupt
325  * @MEI_PG_EVENT_INTR_RECEIVED: the driver received pg event interrupt
326  */
327 enum mei_pg_event {
328 	MEI_PG_EVENT_IDLE,
329 	MEI_PG_EVENT_WAIT,
330 	MEI_PG_EVENT_RECEIVED,
331 	MEI_PG_EVENT_INTR_WAIT,
332 	MEI_PG_EVENT_INTR_RECEIVED,
333 };
334 
335 /**
336  * enum mei_pg_state - device internal power gating state
337  *
338  * @MEI_PG_OFF: device is not power gated - it is active
339  * @MEI_PG_ON:  device is power gated - it is in lower power state
340  */
341 enum mei_pg_state {
342 	MEI_PG_OFF = 0,
343 	MEI_PG_ON =  1,
344 };
345 
346 const char *mei_pg_state_str(enum mei_pg_state state);
347 
348 /**
349  * struct mei_device -  MEI private device struct
350  *
351  * @dev         : device on a bus
352  * @cdev        : character device
353  * @minor       : minor number allocated for device
354  *
355  * @write_list  : write pending list
356  * @write_waiting_list : write completion list
357  * @ctrl_wr_list : pending control write list
358  * @ctrl_rd_list : pending control read list
359  *
360  * @file_list   : list of opened handles
361  * @open_handle_count: number of opened handles
362  *
363  * @device_lock : big device lock
364  * @timer_work  : MEI timer delayed work (timeouts)
365  *
366  * @recvd_hw_ready : hw ready message received flag
367  *
368  * @wait_hw_ready : wait queue for receive HW ready message form FW
369  * @wait_pg     : wait queue for receive PG message from FW
370  * @wait_hbm_start : wait queue for receive HBM start message from FW
371  *
372  * @reset_count : number of consecutive resets
373  * @dev_state   : device state
374  * @hbm_state   : state of host bus message protocol
375  * @init_clients_timer : HBM init handshake timeout
376  *
377  * @pg_event    : power gating event
378  * @pg_domain   : runtime PM domain
379  *
380  * @rd_msg_buf  : control messages buffer
381  * @rd_msg_hdr  : read message header storage
382  *
383  * @hbuf_depth  : depth of hardware host/write buffer is slots
384  * @hbuf_is_ready : query if the host host/write buffer is ready
385  *
386  * @version     : HBM protocol version in use
387  * @hbm_f_pg_supported  : hbm feature pgi protocol
388  * @hbm_f_dc_supported  : hbm feature dynamic clients
389  * @hbm_f_dot_supported : hbm feature disconnect on timeout
390  * @hbm_f_ev_supported  : hbm feature event notification
391  * @hbm_f_fa_supported  : hbm feature fixed address client
392  * @hbm_f_ie_supported  : hbm feature immediate reply to enum request
393  *
394  * @me_clients_rwsem: rw lock over me_clients list
395  * @me_clients  : list of FW clients
396  * @me_clients_map : FW clients bit map
397  * @host_clients_map : host clients id pool
398  *
399  * @allow_fixed_address: allow user space to connect a fixed client
400  * @override_fixed_address: force allow fixed address behavior
401  *
402  * @amthif_cmd_list : amthif list for cmd waiting
403  * @iamthif_fp : file for current amthif operation
404  * @iamthif_cl  : amthif host client
405  * @iamthif_current_cb : amthif current operation callback
406  * @iamthif_open_count : number of opened amthif connections
407  * @iamthif_stall_timer : timer to detect amthif hang
408  * @iamthif_state : amthif processor state
409  * @iamthif_canceled : current amthif command is canceled
410  *
411  * @reset_work  : work item for the device reset
412  * @bus_rescan_work : work item for the bus rescan
413  *
414  * @device_list : mei client bus list
415  * @cl_bus_lock : client bus list lock
416  *
417  * @dbgfs_dir   : debugfs mei root directory
418  *
419  * @ops:        : hw specific operations
420  * @hw          : hw specific data
421  */
422 struct mei_device {
423 	struct device *dev;
424 	struct cdev cdev;
425 	int minor;
426 
427 	struct mei_cl_cb write_list;
428 	struct mei_cl_cb write_waiting_list;
429 	struct mei_cl_cb ctrl_wr_list;
430 	struct mei_cl_cb ctrl_rd_list;
431 
432 	struct list_head file_list;
433 	long open_handle_count;
434 
435 	struct mutex device_lock;
436 	struct delayed_work timer_work;
437 
438 	bool recvd_hw_ready;
439 	/*
440 	 * waiting queue for receive message from FW
441 	 */
442 	wait_queue_head_t wait_hw_ready;
443 	wait_queue_head_t wait_pg;
444 	wait_queue_head_t wait_hbm_start;
445 
446 	/*
447 	 * mei device  states
448 	 */
449 	unsigned long reset_count;
450 	enum mei_dev_state dev_state;
451 	enum mei_hbm_state hbm_state;
452 	u16 init_clients_timer;
453 
454 	/*
455 	 * Power Gating support
456 	 */
457 	enum mei_pg_event pg_event;
458 #ifdef CONFIG_PM
459 	struct dev_pm_domain pg_domain;
460 #endif /* CONFIG_PM */
461 
462 	unsigned char rd_msg_buf[MEI_RD_MSG_BUF_SIZE];
463 	u32 rd_msg_hdr;
464 
465 	/* write buffer */
466 	u8 hbuf_depth;
467 	bool hbuf_is_ready;
468 
469 	struct hbm_version version;
470 	unsigned int hbm_f_pg_supported:1;
471 	unsigned int hbm_f_dc_supported:1;
472 	unsigned int hbm_f_dot_supported:1;
473 	unsigned int hbm_f_ev_supported:1;
474 	unsigned int hbm_f_fa_supported:1;
475 	unsigned int hbm_f_ie_supported:1;
476 
477 	struct rw_semaphore me_clients_rwsem;
478 	struct list_head me_clients;
479 	DECLARE_BITMAP(me_clients_map, MEI_CLIENTS_MAX);
480 	DECLARE_BITMAP(host_clients_map, MEI_CLIENTS_MAX);
481 
482 	bool allow_fixed_address;
483 	bool override_fixed_address;
484 
485 	/* amthif list for cmd waiting */
486 	struct mei_cl_cb amthif_cmd_list;
487 	/* driver managed amthif list for reading completed amthif cmd data */
488 	const struct file *iamthif_fp;
489 	struct mei_cl iamthif_cl;
490 	struct mei_cl_cb *iamthif_current_cb;
491 	long iamthif_open_count;
492 	u32 iamthif_stall_timer;
493 	enum iamthif_states iamthif_state;
494 	bool iamthif_canceled;
495 
496 	struct work_struct reset_work;
497 	struct work_struct bus_rescan_work;
498 
499 	/* List of bus devices */
500 	struct list_head device_list;
501 	struct mutex cl_bus_lock;
502 
503 #if IS_ENABLED(CONFIG_DEBUG_FS)
504 	struct dentry *dbgfs_dir;
505 #endif /* CONFIG_DEBUG_FS */
506 
507 
508 	const struct mei_hw_ops *ops;
509 	char hw[0] __aligned(sizeof(void *));
510 };
511 
512 static inline unsigned long mei_secs_to_jiffies(unsigned long sec)
513 {
514 	return msecs_to_jiffies(sec * MSEC_PER_SEC);
515 }
516 
517 /**
518  * mei_data2slots - get slots - number of (dwords) from a message length
519  *	+ size of the mei header
520  *
521  * @length: size of the messages in bytes
522  *
523  * Return: number of slots
524  */
525 static inline u32 mei_data2slots(size_t length)
526 {
527 	return DIV_ROUND_UP(sizeof(struct mei_msg_hdr) + length, 4);
528 }
529 
530 /**
531  * mei_slots2data - get data in slots - bytes from slots
532  *
533  * @slots: number of available slots
534  *
535  * Return: number of bytes in slots
536  */
537 static inline u32 mei_slots2data(int slots)
538 {
539 	return slots * 4;
540 }
541 
542 /*
543  * mei init function prototypes
544  */
545 void mei_device_init(struct mei_device *dev,
546 		     struct device *device,
547 		     const struct mei_hw_ops *hw_ops);
548 int mei_reset(struct mei_device *dev);
549 int mei_start(struct mei_device *dev);
550 int mei_restart(struct mei_device *dev);
551 void mei_stop(struct mei_device *dev);
552 void mei_cancel_work(struct mei_device *dev);
553 
554 /*
555  *  MEI interrupt functions prototype
556  */
557 
558 void mei_timer(struct work_struct *work);
559 int mei_irq_read_handler(struct mei_device *dev,
560 		struct mei_cl_cb *cmpl_list, s32 *slots);
561 
562 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list);
563 void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list);
564 
565 /*
566  * AMTHIF - AMT Host Interface Functions
567  */
568 void mei_amthif_reset_params(struct mei_device *dev);
569 
570 int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl);
571 
572 int mei_amthif_read(struct mei_device *dev, struct file *file,
573 		char __user *ubuf, size_t length, loff_t *offset);
574 
575 unsigned int mei_amthif_poll(struct mei_device *dev,
576 		struct file *file, poll_table *wait);
577 
578 int mei_amthif_release(struct mei_device *dev, struct file *file);
579 
580 int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb);
581 int mei_amthif_run_next_cmd(struct mei_device *dev);
582 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
583 			struct mei_cl_cb *cmpl_list);
584 
585 void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb);
586 int mei_amthif_irq_read_msg(struct mei_cl *cl,
587 			    struct mei_msg_hdr *mei_hdr,
588 			    struct mei_cl_cb *complete_list);
589 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots);
590 
591 /*
592  * Register Access Function
593  */
594 
595 
596 static inline void mei_hw_config(struct mei_device *dev)
597 {
598 	dev->ops->hw_config(dev);
599 }
600 
601 static inline enum mei_pg_state mei_pg_state(struct mei_device *dev)
602 {
603 	return dev->ops->pg_state(dev);
604 }
605 
606 static inline bool mei_pg_in_transition(struct mei_device *dev)
607 {
608 	return dev->ops->pg_in_transition(dev);
609 }
610 
611 static inline bool mei_pg_is_enabled(struct mei_device *dev)
612 {
613 	return dev->ops->pg_is_enabled(dev);
614 }
615 
616 static inline int mei_hw_reset(struct mei_device *dev, bool enable)
617 {
618 	return dev->ops->hw_reset(dev, enable);
619 }
620 
621 static inline int mei_hw_start(struct mei_device *dev)
622 {
623 	return dev->ops->hw_start(dev);
624 }
625 
626 static inline void mei_clear_interrupts(struct mei_device *dev)
627 {
628 	dev->ops->intr_clear(dev);
629 }
630 
631 static inline void mei_enable_interrupts(struct mei_device *dev)
632 {
633 	dev->ops->intr_enable(dev);
634 }
635 
636 static inline void mei_disable_interrupts(struct mei_device *dev)
637 {
638 	dev->ops->intr_disable(dev);
639 }
640 
641 static inline bool mei_host_is_ready(struct mei_device *dev)
642 {
643 	return dev->ops->host_is_ready(dev);
644 }
645 static inline bool mei_hw_is_ready(struct mei_device *dev)
646 {
647 	return dev->ops->hw_is_ready(dev);
648 }
649 
650 static inline bool mei_hbuf_is_ready(struct mei_device *dev)
651 {
652 	return dev->ops->hbuf_is_ready(dev);
653 }
654 
655 static inline int mei_hbuf_empty_slots(struct mei_device *dev)
656 {
657 	return dev->ops->hbuf_free_slots(dev);
658 }
659 
660 static inline size_t mei_hbuf_max_len(const struct mei_device *dev)
661 {
662 	return dev->ops->hbuf_max_len(dev);
663 }
664 
665 static inline int mei_write_message(struct mei_device *dev,
666 			struct mei_msg_hdr *hdr, void *buf)
667 {
668 	return dev->ops->write(dev, hdr, buf);
669 }
670 
671 static inline u32 mei_read_hdr(const struct mei_device *dev)
672 {
673 	return dev->ops->read_hdr(dev);
674 }
675 
676 static inline void mei_read_slots(struct mei_device *dev,
677 		     unsigned char *buf, unsigned long len)
678 {
679 	dev->ops->read(dev, buf, len);
680 }
681 
682 static inline int mei_count_full_read_slots(struct mei_device *dev)
683 {
684 	return dev->ops->rdbuf_full_slots(dev);
685 }
686 
687 static inline int mei_fw_status(struct mei_device *dev,
688 				struct mei_fw_status *fw_status)
689 {
690 	return dev->ops->fw_status(dev, fw_status);
691 }
692 
693 bool mei_hbuf_acquire(struct mei_device *dev);
694 
695 bool mei_write_is_idle(struct mei_device *dev);
696 
697 void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr);
698 
699 #if IS_ENABLED(CONFIG_DEBUG_FS)
700 int mei_dbgfs_register(struct mei_device *dev, const char *name);
701 void mei_dbgfs_deregister(struct mei_device *dev);
702 #else
703 static inline int mei_dbgfs_register(struct mei_device *dev, const char *name)
704 {
705 	return 0;
706 }
707 static inline void mei_dbgfs_deregister(struct mei_device *dev) {}
708 #endif /* CONFIG_DEBUG_FS */
709 
710 int mei_register(struct mei_device *dev, struct device *parent);
711 void mei_deregister(struct mei_device *dev);
712 
713 #define MEI_HDR_FMT "hdr:host=%02d me=%02d len=%d internal=%1d comp=%1d"
714 #define MEI_HDR_PRM(hdr)                  \
715 	(hdr)->host_addr, (hdr)->me_addr, \
716 	(hdr)->length, (hdr)->internal, (hdr)->msg_complete
717 
718 ssize_t mei_fw_status2str(struct mei_fw_status *fw_sts, char *buf, size_t len);
719 /**
720  * mei_fw_status_str - fetch and convert fw status registers to printable string
721  *
722  * @dev: the device structure
723  * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
724  * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
725  *
726  * Return: number of bytes written or < 0 on failure
727  */
728 static inline ssize_t mei_fw_status_str(struct mei_device *dev,
729 					char *buf, size_t len)
730 {
731 	struct mei_fw_status fw_status;
732 	int ret;
733 
734 	buf[0] = '\0';
735 
736 	ret = mei_fw_status(dev, &fw_status);
737 	if (ret)
738 		return ret;
739 
740 	ret = mei_fw_status2str(&fw_status, buf, MEI_FW_STATUS_STR_SZ);
741 
742 	return ret;
743 }
744 
745 
746 #endif
747