tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
33extern 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 */
57enum 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 */
68enum 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
78const char *mei_dev_state_str(int state);
79
80enum 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
88enum 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 */
107enum 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 */
120struct 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 */
137struct 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 */
153struct 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
164struct 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 */
179struct 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 */
217struct 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 */
271struct 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*/
306void mei_cl_bus_rescan(struct mei_device *bus);
307void mei_cl_bus_rescan_work(struct work_struct *work);
308void mei_cl_bus_dev_fixup(struct mei_cl_device *dev);
309ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
310 bool blocking);
311ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length);
312bool mei_cl_bus_rx_event(struct mei_cl *cl);
313bool mei_cl_bus_notify_event(struct mei_cl *cl);
314void mei_cl_bus_remove_devices(struct mei_device *bus);
315int mei_cl_bus_init(void);
316void 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 */
327enum 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 */
341enum mei_pg_state {
342 MEI_PG_OFF = 0,
343 MEI_PG_ON = 1,
344};
345
346const 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 */
422struct 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
512static 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 */
525static 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 */
537static inline u32 mei_slots2data(int slots)
538{
539 return slots * 4;
540}
541
542/*
543 * mei init function prototypes
544 */
545void mei_device_init(struct mei_device *dev,
546 struct device *device,
547 const struct mei_hw_ops *hw_ops);
548int mei_reset(struct mei_device *dev);
549int mei_start(struct mei_device *dev);
550int mei_restart(struct mei_device *dev);
551void mei_stop(struct mei_device *dev);
552void mei_cancel_work(struct mei_device *dev);
553
554/*
555 * MEI interrupt functions prototype
556 */
557
558void mei_timer(struct work_struct *work);
559int mei_irq_read_handler(struct mei_device *dev,
560 struct mei_cl_cb *cmpl_list, s32 *slots);
561
562int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list);
563void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list);
564
565/*
566 * AMTHIF - AMT Host Interface Functions
567 */
568void mei_amthif_reset_params(struct mei_device *dev);
569
570int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl);
571
572int mei_amthif_read(struct mei_device *dev, struct file *file,
573 char __user *ubuf, size_t length, loff_t *offset);
574
575unsigned int mei_amthif_poll(struct mei_device *dev,
576 struct file *file, poll_table *wait);
577
578int mei_amthif_release(struct mei_device *dev, struct file *file);
579
580int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb);
581int mei_amthif_run_next_cmd(struct mei_device *dev);
582int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
583 struct mei_cl_cb *cmpl_list);
584
585void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb);
586int mei_amthif_irq_read_msg(struct mei_cl *cl,
587 struct mei_msg_hdr *mei_hdr,
588 struct mei_cl_cb *complete_list);
589int mei_amthif_irq_read(struct mei_device *dev, s32 *slots);
590
591/*
592 * Register Access Function
593 */
594
595
596static inline void mei_hw_config(struct mei_device *dev)
597{
598 dev->ops->hw_config(dev);
599}
600
601static inline enum mei_pg_state mei_pg_state(struct mei_device *dev)
602{
603 return dev->ops->pg_state(dev);
604}
605
606static inline bool mei_pg_in_transition(struct mei_device *dev)
607{
608 return dev->ops->pg_in_transition(dev);
609}
610
611static inline bool mei_pg_is_enabled(struct mei_device *dev)
612{
613 return dev->ops->pg_is_enabled(dev);
614}
615
616static inline int mei_hw_reset(struct mei_device *dev, bool enable)
617{
618 return dev->ops->hw_reset(dev, enable);
619}
620
621static inline int mei_hw_start(struct mei_device *dev)
622{
623 return dev->ops->hw_start(dev);
624}
625
626static inline void mei_clear_interrupts(struct mei_device *dev)
627{
628 dev->ops->intr_clear(dev);
629}
630
631static inline void mei_enable_interrupts(struct mei_device *dev)
632{
633 dev->ops->intr_enable(dev);
634}
635
636static inline void mei_disable_interrupts(struct mei_device *dev)
637{
638 dev->ops->intr_disable(dev);
639}
640
641static inline bool mei_host_is_ready(struct mei_device *dev)
642{
643 return dev->ops->host_is_ready(dev);
644}
645static inline bool mei_hw_is_ready(struct mei_device *dev)
646{
647 return dev->ops->hw_is_ready(dev);
648}
649
650static inline bool mei_hbuf_is_ready(struct mei_device *dev)
651{
652 return dev->ops->hbuf_is_ready(dev);
653}
654
655static inline int mei_hbuf_empty_slots(struct mei_device *dev)
656{
657 return dev->ops->hbuf_free_slots(dev);
658}
659
660static inline size_t mei_hbuf_max_len(const struct mei_device *dev)
661{
662 return dev->ops->hbuf_max_len(dev);
663}
664
665static 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
671static inline u32 mei_read_hdr(const struct mei_device *dev)
672{
673 return dev->ops->read_hdr(dev);
674}
675
676static 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
682static inline int mei_count_full_read_slots(struct mei_device *dev)
683{
684 return dev->ops->rdbuf_full_slots(dev);
685}
686
687static 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
693bool mei_hbuf_acquire(struct mei_device *dev);
694
695bool mei_write_is_idle(struct mei_device *dev);
696
697void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr);
698
699#if IS_ENABLED(CONFIG_DEBUG_FS)
700int mei_dbgfs_register(struct mei_device *dev, const char *name);
701void mei_dbgfs_deregister(struct mei_device *dev);
702#else
703static inline int mei_dbgfs_register(struct mei_device *dev, const char *name)
704{
705 return 0;
706}
707static inline void mei_dbgfs_deregister(struct mei_device *dev) {}
708#endif /* CONFIG_DEBUG_FS */
709
710int mei_register(struct mei_device *dev, struct device *parent);
711void 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
718ssize_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 */
728static 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