1 // SPDX-License-Identifier: GPL-2.0+
4 * Multifunction core driver for Zodiac Inflight Innovations RAVE
5 * Supervisory Processor(SP) MCU that is connected via dedicated UART
8 * Copyright (C) 2017 Zodiac Inflight Innovations
11 #include <linux/atomic.h>
12 #include <linux/crc-ccitt.h>
13 #include <linux/delay.h>
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/kernel.h>
18 #include <linux/mfd/rave-sp.h>
19 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/sched.h>
23 #include <linux/serdev.h>
24 #include <asm/unaligned.h>
27 * UART protocol using following entities:
28 * - message to MCU => ACK response
29 * - event from MCU => event ACK
32 * <STX> <DATA> <CHECKSUM> <ETX>
34 * - STX - is start of transmission character
35 * - ETX - end of transmission
37 * - CHECKSUM - checksum calculated on <DATA>
39 * If <DATA> or <CHECKSUM> contain one of control characters, then it is
40 * escaped using <DLE> control code. Added <DLE> does not participate in
41 * checksum calculation.
43 #define RAVE_SP_STX 0x02
44 #define RAVE_SP_ETX 0x03
45 #define RAVE_SP_DLE 0x10
47 #define RAVE_SP_MAX_DATA_SIZE 64
48 #define RAVE_SP_CHECKSUM_8B2C 1
49 #define RAVE_SP_CHECKSUM_CCITT 2
50 #define RAVE_SP_CHECKSUM_SIZE RAVE_SP_CHECKSUM_CCITT
52 * We don't store STX, ETX and unescaped bytes, so Rx is only
55 #define RAVE_SP_RX_BUFFER_SIZE \
56 (RAVE_SP_MAX_DATA_SIZE + RAVE_SP_CHECKSUM_SIZE)
58 #define RAVE_SP_STX_ETX_SIZE 2
60 * For Tx we have to have space for everything, STX, EXT and
61 * potentially stuffed DATA + CSUM data + csum
63 #define RAVE_SP_TX_BUFFER_SIZE \
64 (RAVE_SP_STX_ETX_SIZE + 2 * RAVE_SP_RX_BUFFER_SIZE)
67 * enum rave_sp_deframer_state - Possible state for de-framer
69 * @RAVE_SP_EXPECT_SOF: Scanning input for start-of-frame marker
70 * @RAVE_SP_EXPECT_DATA: Got start of frame marker, collecting frame
71 * @RAVE_SP_EXPECT_ESCAPED_DATA: Got escape character, collecting escaped byte
73 enum rave_sp_deframer_state
{
76 RAVE_SP_EXPECT_ESCAPED_DATA
,
80 * struct rave_sp_deframer - Device protocol deframer
82 * @state: Current state of the deframer
83 * @data: Buffer used to collect deframed data
84 * @length: Number of bytes de-framed so far
86 struct rave_sp_deframer
{
87 enum rave_sp_deframer_state state
;
88 unsigned char data
[RAVE_SP_RX_BUFFER_SIZE
];
93 * struct rave_sp_reply - Reply as per RAVE device protocol
95 * @length: Expected reply length
96 * @data: Buffer to store reply payload in
97 * @code: Expected reply code
98 * @ackid: Expected reply ACK ID
99 * @completion: Successful reply reception completion
101 struct rave_sp_reply
{
106 struct completion received
;
110 * struct rave_sp_checksum - Variant specific checksum implementation details
112 * @length: Calculated checksum length
113 * @subroutine: Utilized checksum algorithm implementation
115 struct rave_sp_checksum
{
117 void (*subroutine
)(const u8
*, size_t, u8
*);
120 struct rave_sp_version
{
127 struct rave_sp_status
{
128 struct rave_sp_version bootloader_version
;
129 struct rave_sp_version firmware_version
;
136 u8 backlight_current
[3];
140 u8 i2c_device_status
;
146 u8 periph_power_shutoff
;
150 * struct rave_sp_variant_cmds - Variant specific command routines
152 * @translate: Generic to variant specific command mapping routine
153 * @get_status: Variant specific implementation of CMD_GET_STATUS
155 struct rave_sp_variant_cmds
{
156 int (*translate
)(enum rave_sp_command
);
157 int (*get_status
)(struct rave_sp
*sp
, struct rave_sp_status
*);
161 * struct rave_sp_variant - RAVE supervisory processor core variant
163 * @checksum: Variant specific checksum implementation
164 * @cmd: Variant specific command pointer table
167 struct rave_sp_variant
{
168 const struct rave_sp_checksum
*checksum
;
169 struct rave_sp_variant_cmds cmd
;
173 * struct rave_sp - RAVE supervisory processor core
175 * @serdev: Pointer to underlying serdev
176 * @deframer: Stored state of the protocol deframer
177 * @ackid: ACK ID used in last reply sent to the device
178 * @bus_lock: Lock to serialize access to the device
179 * @reply_lock: Lock protecting @reply
180 * @reply: Pointer to memory to store reply payload
182 * @variant: Device variant specific information
183 * @event_notifier_list: Input event notification chain
185 * @part_number_firmware: Firmware version
186 * @part_number_bootloader: Bootloader version
189 struct serdev_device
*serdev
;
190 struct rave_sp_deframer deframer
;
192 struct mutex bus_lock
;
193 struct mutex reply_lock
;
194 struct rave_sp_reply
*reply
;
196 const struct rave_sp_variant
*variant
;
197 struct blocking_notifier_head event_notifier_list
;
199 const char *part_number_firmware
;
200 const char *part_number_bootloader
;
203 static bool rave_sp_id_is_event(u8 code
)
205 return (code
& 0xF0) == RAVE_SP_EVNT_BASE
;
208 static void rave_sp_unregister_event_notifier(struct device
*dev
, void *res
)
210 struct rave_sp
*sp
= dev_get_drvdata(dev
->parent
);
211 struct notifier_block
*nb
= *(struct notifier_block
**)res
;
212 struct blocking_notifier_head
*bnh
= &sp
->event_notifier_list
;
214 WARN_ON(blocking_notifier_chain_unregister(bnh
, nb
));
217 int devm_rave_sp_register_event_notifier(struct device
*dev
,
218 struct notifier_block
*nb
)
220 struct rave_sp
*sp
= dev_get_drvdata(dev
->parent
);
221 struct notifier_block
**rcnb
;
224 rcnb
= devres_alloc(rave_sp_unregister_event_notifier
,
225 sizeof(*rcnb
), GFP_KERNEL
);
229 ret
= blocking_notifier_chain_register(&sp
->event_notifier_list
, nb
);
232 devres_add(dev
, rcnb
);
239 EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier
);
241 static void csum_8b2c(const u8
*buf
, size_t size
, u8
*crc
)
252 static void csum_ccitt(const u8
*buf
, size_t size
, u8
*crc
)
254 const u16 calculated
= crc_ccitt_false(0xffff, buf
, size
);
257 * While the rest of the wire protocol is little-endian,
258 * CCITT-16 CRC in RDU2 device is sent out in big-endian order.
260 put_unaligned_be16(calculated
, crc
);
263 static void *stuff(unsigned char *dest
, const unsigned char *src
, size_t n
)
266 const unsigned char byte
= *src
++;
272 *dest
++ = RAVE_SP_DLE
;
282 static int rave_sp_write(struct rave_sp
*sp
, const u8
*data
, u8 data_size
)
284 const size_t checksum_length
= sp
->variant
->checksum
->length
;
285 unsigned char frame
[RAVE_SP_TX_BUFFER_SIZE
];
286 unsigned char crc
[RAVE_SP_CHECKSUM_SIZE
];
287 unsigned char *dest
= frame
;
290 if (WARN_ON(checksum_length
> sizeof(crc
)))
293 if (WARN_ON(data_size
> sizeof(frame
)))
296 sp
->variant
->checksum
->subroutine(data
, data_size
, crc
);
298 *dest
++ = RAVE_SP_STX
;
299 dest
= stuff(dest
, data
, data_size
);
300 dest
= stuff(dest
, crc
, checksum_length
);
301 *dest
++ = RAVE_SP_ETX
;
303 length
= dest
- frame
;
305 print_hex_dump_debug("rave-sp tx: ", DUMP_PREFIX_NONE
,
306 16, 1, frame
, length
, false);
308 return serdev_device_write(sp
->serdev
, frame
, length
, HZ
);
311 static u8
rave_sp_reply_code(u8 command
)
314 * There isn't a single rule that describes command code ->
315 * ACK code transformation, but, going through various
316 * versions of ICDs, there appear to be three distinct groups
317 * that can be described by simple transformation.
322 * Commands implemented by firmware found in RDU1 and
323 * older devices all seem to obey the following rule
325 return command
+ 0x20;
328 * Events emitted by all versions of the firmare use
329 * least significant bit to get an ACK code
331 return command
| 0x01;
334 * Commands implemented by firmware found in RDU2 are
335 * similar to "old" commands, but they use slightly
338 return command
+ 0x40;
342 int rave_sp_exec(struct rave_sp
*sp
,
343 void *__data
, size_t data_size
,
344 void *reply_data
, size_t reply_data_size
)
346 struct rave_sp_reply reply
= {
348 .length
= reply_data_size
,
349 .received
= COMPLETION_INITIALIZER_ONSTACK(reply
.received
),
351 unsigned char *data
= __data
;
352 int command
, ret
= 0;
355 command
= sp
->variant
->cmd
.translate(data
[0]);
359 ackid
= atomic_inc_return(&sp
->ackid
);
361 reply
.code
= rave_sp_reply_code((u8
)command
),
363 mutex_lock(&sp
->bus_lock
);
365 mutex_lock(&sp
->reply_lock
);
367 mutex_unlock(&sp
->reply_lock
);
372 rave_sp_write(sp
, data
, data_size
);
374 if (!wait_for_completion_timeout(&reply
.received
, HZ
)) {
375 dev_err(&sp
->serdev
->dev
, "Command timeout\n");
378 mutex_lock(&sp
->reply_lock
);
380 mutex_unlock(&sp
->reply_lock
);
383 mutex_unlock(&sp
->bus_lock
);
386 EXPORT_SYMBOL_GPL(rave_sp_exec
);
388 static void rave_sp_receive_event(struct rave_sp
*sp
,
389 const unsigned char *data
, size_t length
)
392 [0] = rave_sp_reply_code(data
[0]),
396 rave_sp_write(sp
, cmd
, sizeof(cmd
));
398 blocking_notifier_call_chain(&sp
->event_notifier_list
,
399 rave_sp_action_pack(data
[0], data
[2]),
403 static void rave_sp_receive_reply(struct rave_sp
*sp
,
404 const unsigned char *data
, size_t length
)
406 struct device
*dev
= &sp
->serdev
->dev
;
407 struct rave_sp_reply
*reply
;
408 const size_t payload_length
= length
- 2;
410 mutex_lock(&sp
->reply_lock
);
414 if (reply
->code
== data
[0] && reply
->ackid
== data
[1] &&
415 payload_length
>= reply
->length
) {
417 * We are relying on memcpy(dst, src, 0) to be a no-op
418 * when handling commands that have a no-payload reply
420 memcpy(reply
->data
, &data
[2], reply
->length
);
421 complete(&reply
->received
);
424 dev_err(dev
, "Ignoring incorrect reply\n");
425 dev_dbg(dev
, "Code: expected = 0x%08x received = 0x%08x\n",
426 reply
->code
, data
[0]);
427 dev_dbg(dev
, "ACK ID: expected = 0x%08x received = 0x%08x\n",
428 reply
->ackid
, data
[1]);
429 dev_dbg(dev
, "Length: expected = %zu received = %zu\n",
430 reply
->length
, payload_length
);
434 mutex_unlock(&sp
->reply_lock
);
437 static void rave_sp_receive_frame(struct rave_sp
*sp
,
438 const unsigned char *data
,
441 const size_t checksum_length
= sp
->variant
->checksum
->length
;
442 const size_t payload_length
= length
- checksum_length
;
443 const u8
*crc_reported
= &data
[payload_length
];
444 struct device
*dev
= &sp
->serdev
->dev
;
445 u8 crc_calculated
[RAVE_SP_CHECKSUM_SIZE
];
447 if (unlikely(checksum_length
> sizeof(crc_calculated
))) {
448 dev_warn(dev
, "Checksum too long, dropping\n");
452 print_hex_dump_debug("rave-sp rx: ", DUMP_PREFIX_NONE
,
453 16, 1, data
, length
, false);
455 if (unlikely(length
<= checksum_length
)) {
456 dev_warn(dev
, "Dropping short frame\n");
460 sp
->variant
->checksum
->subroutine(data
, payload_length
,
463 if (memcmp(crc_calculated
, crc_reported
, checksum_length
)) {
464 dev_warn(dev
, "Dropping bad frame\n");
468 if (rave_sp_id_is_event(data
[0]))
469 rave_sp_receive_event(sp
, data
, length
);
471 rave_sp_receive_reply(sp
, data
, length
);
474 static int rave_sp_receive_buf(struct serdev_device
*serdev
,
475 const unsigned char *buf
, size_t size
)
477 struct device
*dev
= &serdev
->dev
;
478 struct rave_sp
*sp
= dev_get_drvdata(dev
);
479 struct rave_sp_deframer
*deframer
= &sp
->deframer
;
480 const unsigned char *src
= buf
;
481 const unsigned char *end
= buf
+ size
;
484 const unsigned char byte
= *src
++;
486 switch (deframer
->state
) {
487 case RAVE_SP_EXPECT_SOF
:
488 if (byte
== RAVE_SP_STX
)
489 deframer
->state
= RAVE_SP_EXPECT_DATA
;
492 case RAVE_SP_EXPECT_DATA
:
494 * Treat special byte values first
498 rave_sp_receive_frame(sp
,
502 * Once we extracted a complete frame
503 * out of a stream, we call it done
504 * and proceed to bailing out while
505 * resetting the framer to initial
506 * state, regardless if we've consumed
507 * all of the stream or not.
511 dev_warn(dev
, "Bad frame: STX before ETX\n");
513 * If we encounter second "start of
514 * the frame" marker before seeing
515 * corresponding "end of frame", we
516 * reset the framer and ignore both:
517 * frame started by first SOF and
518 * frame started by current SOF.
520 * NOTE: The above means that only the
521 * frame started by third SOF, sent
522 * after this one will have a chance
527 deframer
->state
= RAVE_SP_EXPECT_ESCAPED_DATA
;
529 * If we encounter escape sequence we
530 * need to skip it and collect the
531 * byte that follows. We do it by
532 * forcing the next iteration of the
533 * encompassing while loop.
538 * For the rest of the bytes, that are not
539 * speical snoflakes, we do the same thing
540 * that we do to escaped data - collect it in
546 case RAVE_SP_EXPECT_ESCAPED_DATA
:
547 if (deframer
->length
== sizeof(deframer
->data
)) {
548 dev_warn(dev
, "Bad frame: Too long\n");
550 * If the amount of data we've
551 * accumulated for current frame so
552 * far starts to exceed the capacity
553 * of deframer's buffer, there's
554 * nothing else we can do but to
555 * discard that data and start
556 * assemblying a new frame again
561 deframer
->data
[deframer
->length
++] = byte
;
564 * We've extracted out special byte, now we
565 * can go back to regular data collecting
567 deframer
->state
= RAVE_SP_EXPECT_DATA
;
573 * The only way to get out of the above loop and end up here
574 * is throught consuming all of the supplied data, so here we
575 * report that we processed it all.
581 * NOTE: A number of codepaths that will drop us here will do
582 * so before consuming all 'size' bytes of the data passed by
583 * serdev layer. We rely on the fact that serdev layer will
584 * re-execute this handler with the remainder of the Rx bytes
585 * once we report actual number of bytes that we processed.
587 deframer
->state
= RAVE_SP_EXPECT_SOF
;
588 deframer
->length
= 0;
593 static int rave_sp_rdu1_cmd_translate(enum rave_sp_command command
)
595 if (command
>= RAVE_SP_CMD_STATUS
&&
596 command
<= RAVE_SP_CMD_CONTROL_EVENTS
)
602 static int rave_sp_rdu2_cmd_translate(enum rave_sp_command command
)
604 if (command
>= RAVE_SP_CMD_GET_FIRMWARE_VERSION
&&
605 command
<= RAVE_SP_CMD_GET_GPIO_STATE
)
608 if (command
== RAVE_SP_CMD_REQ_COPPER_REV
) {
610 * As per RDU2 ICD 3.4.47 CMD_GET_COPPER_REV code is
611 * different from that for RDU1 and it is set to 0x28.
616 return rave_sp_rdu1_cmd_translate(command
);
619 static int rave_sp_default_cmd_translate(enum rave_sp_command command
)
622 * All of the following command codes were taken from "Table :
623 * Communications Protocol Message Types" in section 3.3
624 * "MESSAGE TYPES" of Rave PIC24 ICD.
627 case RAVE_SP_CMD_GET_FIRMWARE_VERSION
:
629 case RAVE_SP_CMD_GET_BOOTLOADER_VERSION
:
631 case RAVE_SP_CMD_BOOT_SOURCE
:
633 case RAVE_SP_CMD_SW_WDT
:
635 case RAVE_SP_CMD_PET_WDT
:
637 case RAVE_SP_CMD_RESET
:
639 case RAVE_SP_CMD_RESET_REASON
:
641 case RAVE_SP_CMD_RMB_EEPROM
:
648 static const char *devm_rave_sp_version(struct device
*dev
,
649 struct rave_sp_version
*version
)
652 * NOTE: The format string below uses %02d to display u16
653 * intentionally for the sake of backwards compatibility with
656 return devm_kasprintf(dev
, GFP_KERNEL
, "%02d%02d%02d.%c%c\n",
658 le16_to_cpu(version
->major
),
664 static int rave_sp_rdu1_get_status(struct rave_sp
*sp
,
665 struct rave_sp_status
*status
)
668 [0] = RAVE_SP_CMD_STATUS
,
672 return rave_sp_exec(sp
, cmd
, sizeof(cmd
), status
, sizeof(*status
));
675 static int rave_sp_emulated_get_status(struct rave_sp
*sp
,
676 struct rave_sp_status
*status
)
679 [0] = RAVE_SP_CMD_GET_FIRMWARE_VERSION
,
684 ret
= rave_sp_exec(sp
, cmd
, sizeof(cmd
), &status
->firmware_version
,
685 sizeof(status
->firmware_version
));
689 cmd
[0] = RAVE_SP_CMD_GET_BOOTLOADER_VERSION
;
690 return rave_sp_exec(sp
, cmd
, sizeof(cmd
), &status
->bootloader_version
,
691 sizeof(status
->bootloader_version
));
694 static int rave_sp_get_status(struct rave_sp
*sp
)
696 struct device
*dev
= &sp
->serdev
->dev
;
697 struct rave_sp_status status
;
701 ret
= sp
->variant
->cmd
.get_status(sp
, &status
);
705 version
= devm_rave_sp_version(dev
, &status
.firmware_version
);
709 sp
->part_number_firmware
= version
;
711 version
= devm_rave_sp_version(dev
, &status
.bootloader_version
);
715 sp
->part_number_bootloader
= version
;
720 static const struct rave_sp_checksum rave_sp_checksum_8b2c
= {
722 .subroutine
= csum_8b2c
,
725 static const struct rave_sp_checksum rave_sp_checksum_ccitt
= {
727 .subroutine
= csum_ccitt
,
730 static const struct rave_sp_variant rave_sp_legacy
= {
731 .checksum
= &rave_sp_checksum_ccitt
,
733 .translate
= rave_sp_default_cmd_translate
,
734 .get_status
= rave_sp_emulated_get_status
,
738 static const struct rave_sp_variant rave_sp_rdu1
= {
739 .checksum
= &rave_sp_checksum_8b2c
,
741 .translate
= rave_sp_rdu1_cmd_translate
,
742 .get_status
= rave_sp_rdu1_get_status
,
746 static const struct rave_sp_variant rave_sp_rdu2
= {
747 .checksum
= &rave_sp_checksum_ccitt
,
749 .translate
= rave_sp_rdu2_cmd_translate
,
750 .get_status
= rave_sp_emulated_get_status
,
754 static const struct of_device_id rave_sp_dt_ids
[] = {
755 { .compatible
= "zii,rave-sp-niu", .data
= &rave_sp_legacy
},
756 { .compatible
= "zii,rave-sp-mezz", .data
= &rave_sp_legacy
},
757 { .compatible
= "zii,rave-sp-esb", .data
= &rave_sp_legacy
},
758 { .compatible
= "zii,rave-sp-rdu1", .data
= &rave_sp_rdu1
},
759 { .compatible
= "zii,rave-sp-rdu2", .data
= &rave_sp_rdu2
},
763 static const struct serdev_device_ops rave_sp_serdev_device_ops
= {
764 .receive_buf
= rave_sp_receive_buf
,
765 .write_wakeup
= serdev_device_write_wakeup
,
768 static int rave_sp_probe(struct serdev_device
*serdev
)
770 struct device
*dev
= &serdev
->dev
;
771 const char *unknown
= "unknown\n";
776 if (of_property_read_u32(dev
->of_node
, "current-speed", &baud
)) {
778 "'current-speed' is not specified in device node\n");
782 sp
= devm_kzalloc(dev
, sizeof(*sp
), GFP_KERNEL
);
787 dev_set_drvdata(dev
, sp
);
789 sp
->variant
= of_device_get_match_data(dev
);
793 mutex_init(&sp
->bus_lock
);
794 mutex_init(&sp
->reply_lock
);
795 BLOCKING_INIT_NOTIFIER_HEAD(&sp
->event_notifier_list
);
797 serdev_device_set_client_ops(serdev
, &rave_sp_serdev_device_ops
);
798 ret
= devm_serdev_device_open(dev
, serdev
);
802 serdev_device_set_baudrate(serdev
, baud
);
803 serdev_device_set_flow_control(serdev
, false);
805 ret
= serdev_device_set_parity(serdev
, SERDEV_PARITY_NONE
);
807 dev_err(dev
, "Failed to set parity\n");
811 ret
= rave_sp_get_status(sp
);
813 dev_warn(dev
, "Failed to get firmware status: %d\n", ret
);
814 sp
->part_number_firmware
= unknown
;
815 sp
->part_number_bootloader
= unknown
;
819 * Those strings already have a \n embedded, so there's no
820 * need to have one in format string.
822 dev_info(dev
, "Firmware version: %s", sp
->part_number_firmware
);
823 dev_info(dev
, "Bootloader version: %s", sp
->part_number_bootloader
);
825 return devm_of_platform_populate(dev
);
828 MODULE_DEVICE_TABLE(of
, rave_sp_dt_ids
);
830 static struct serdev_device_driver rave_sp_drv
= {
831 .probe
= rave_sp_probe
,
834 .of_match_table
= rave_sp_dt_ids
,
837 module_serdev_device_driver(rave_sp_drv
);
839 MODULE_LICENSE("GPL");
840 MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
841 MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
842 MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
843 MODULE_DESCRIPTION("RAVE SP core driver");