UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity
OpenCloudOS-Kernel/drivers/mfd/rave-sp.c

844 lines
21 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0+
/*
* Multifunction core driver for Zodiac Inflight Innovations RAVE
* Supervisory Processor(SP) MCU that is connected via dedicated UART
* port
*
* Copyright (C) 2017 Zodiac Inflight Innovations
*/
#include <linux/atomic.h>
#include <linux/crc-ccitt.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/mfd/rave-sp.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/sched.h>
#include <linux/serdev.h>
#include <asm/unaligned.h>
/*
* UART protocol using following entities:
* - message to MCU => ACK response
* - event from MCU => event ACK
*
* Frame structure:
* <STX> <DATA> <CHECKSUM> <ETX>
* Where:
* - STX - is start of transmission character
* - ETX - end of transmission
* - DATA - payload
* - CHECKSUM - checksum calculated on <DATA>
*
* If <DATA> or <CHECKSUM> contain one of control characters, then it is
* escaped using <DLE> control code. Added <DLE> does not participate in
* checksum calculation.
*/
#define RAVE_SP_STX 0x02
#define RAVE_SP_ETX 0x03
#define RAVE_SP_DLE 0x10
#define RAVE_SP_MAX_DATA_SIZE 64
#define RAVE_SP_CHECKSUM_8B2C 1
#define RAVE_SP_CHECKSUM_CCITT 2
#define RAVE_SP_CHECKSUM_SIZE RAVE_SP_CHECKSUM_CCITT
/*
* We don't store STX, ETX and unescaped bytes, so Rx is only
* DATA + CSUM
*/
#define RAVE_SP_RX_BUFFER_SIZE \
(RAVE_SP_MAX_DATA_SIZE + RAVE_SP_CHECKSUM_SIZE)
#define RAVE_SP_STX_ETX_SIZE 2
/*
* For Tx we have to have space for everything, STX, EXT and
* potentially stuffed DATA + CSUM data + csum
*/
#define RAVE_SP_TX_BUFFER_SIZE \
(RAVE_SP_STX_ETX_SIZE + 2 * RAVE_SP_RX_BUFFER_SIZE)
/**
* enum rave_sp_deframer_state - Possible state for de-framer
*
* @RAVE_SP_EXPECT_SOF: Scanning input for start-of-frame marker
* @RAVE_SP_EXPECT_DATA: Got start of frame marker, collecting frame
* @RAVE_SP_EXPECT_ESCAPED_DATA: Got escape character, collecting escaped byte
*/
enum rave_sp_deframer_state {
RAVE_SP_EXPECT_SOF,
RAVE_SP_EXPECT_DATA,
RAVE_SP_EXPECT_ESCAPED_DATA,
};
/**
* struct rave_sp_deframer - Device protocol deframer
*
* @state: Current state of the deframer
* @data: Buffer used to collect deframed data
* @length: Number of bytes de-framed so far
*/
struct rave_sp_deframer {
enum rave_sp_deframer_state state;
unsigned char data[RAVE_SP_RX_BUFFER_SIZE];
size_t length;
};
/**
* struct rave_sp_reply - Reply as per RAVE device protocol
*
* @length: Expected reply length
* @data: Buffer to store reply payload in
* @code: Expected reply code
* @ackid: Expected reply ACK ID
* @completion: Successful reply reception completion
*/
struct rave_sp_reply {
size_t length;
void *data;
u8 code;
u8 ackid;
struct completion received;
};
/**
* struct rave_sp_checksum - Variant specific checksum implementation details
*
* @length: Calculated checksum length
* @subroutine: Utilized checksum algorithm implementation
*/
struct rave_sp_checksum {
size_t length;
void (*subroutine)(const u8 *, size_t, u8 *);
};
struct rave_sp_version {
u8 hardware;
__le16 major;
u8 minor;
u8 letter[2];
} __packed;
struct rave_sp_status {
struct rave_sp_version bootloader_version;
struct rave_sp_version firmware_version;
u16 rdu_eeprom_flag;
u16 dds_eeprom_flag;
u8 pic_flag;
u8 orientation;
u32 etc;
s16 temp[2];
u8 backlight_current[3];
u8 dip_switch;
u8 host_interrupt;
u16 voltage_28;
u8 i2c_device_status;
u8 power_status;
u8 general_status;
u8 deprecated1;
u8 power_led_status;
u8 deprecated2;
u8 periph_power_shutoff;
} __packed;
/**
* struct rave_sp_variant_cmds - Variant specific command routines
*
* @translate: Generic to variant specific command mapping routine
* @get_status: Variant specific implementation of CMD_GET_STATUS
*/
struct rave_sp_variant_cmds {
int (*translate)(enum rave_sp_command);
int (*get_status)(struct rave_sp *sp, struct rave_sp_status *);
};
/**
* struct rave_sp_variant - RAVE supervisory processor core variant
*
* @checksum: Variant specific checksum implementation
* @cmd: Variant specific command pointer table
*
*/
struct rave_sp_variant {
const struct rave_sp_checksum *checksum;
struct rave_sp_variant_cmds cmd;
};
/**
* struct rave_sp - RAVE supervisory processor core
*
* @serdev: Pointer to underlying serdev
* @deframer: Stored state of the protocol deframer
* @ackid: ACK ID used in last reply sent to the device
* @bus_lock: Lock to serialize access to the device
* @reply_lock: Lock protecting @reply
* @reply: Pointer to memory to store reply payload
*
* @variant: Device variant specific information
* @event_notifier_list: Input event notification chain
*
* @part_number_firmware: Firmware version
* @part_number_bootloader: Bootloader version
*/
struct rave_sp {
struct serdev_device *serdev;
struct rave_sp_deframer deframer;
atomic_t ackid;
struct mutex bus_lock;
struct mutex reply_lock;
struct rave_sp_reply *reply;
const struct rave_sp_variant *variant;
struct blocking_notifier_head event_notifier_list;
const char *part_number_firmware;
const char *part_number_bootloader;
};
static bool rave_sp_id_is_event(u8 code)
{
return (code & 0xF0) == RAVE_SP_EVNT_BASE;
}
static void rave_sp_unregister_event_notifier(struct device *dev, void *res)
{
struct rave_sp *sp = dev_get_drvdata(dev->parent);
struct notifier_block *nb = *(struct notifier_block **)res;
struct blocking_notifier_head *bnh = &sp->event_notifier_list;
WARN_ON(blocking_notifier_chain_unregister(bnh, nb));
}
int devm_rave_sp_register_event_notifier(struct device *dev,
struct notifier_block *nb)
{
struct rave_sp *sp = dev_get_drvdata(dev->parent);
struct notifier_block **rcnb;
int ret;
rcnb = devres_alloc(rave_sp_unregister_event_notifier,
sizeof(*rcnb), GFP_KERNEL);
if (!rcnb)
return -ENOMEM;
ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
if (!ret) {
*rcnb = nb;
devres_add(dev, rcnb);
} else {
devres_free(rcnb);
}
return ret;
}
EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);
static void csum_8b2c(const u8 *buf, size_t size, u8 *crc)
{
*crc = *buf++;
size--;
while (size--)
*crc += *buf++;
*crc = 1 + ~(*crc);
}
static void csum_ccitt(const u8 *buf, size_t size, u8 *crc)
{
const u16 calculated = crc_ccitt_false(0xffff, buf, size);
/*
* While the rest of the wire protocol is little-endian,
* CCITT-16 CRC in RDU2 device is sent out in big-endian order.
*/
put_unaligned_be16(calculated, crc);
}
static void *stuff(unsigned char *dest, const unsigned char *src, size_t n)
{
while (n--) {
const unsigned char byte = *src++;
switch (byte) {
case RAVE_SP_STX:
case RAVE_SP_ETX:
case RAVE_SP_DLE:
*dest++ = RAVE_SP_DLE;
/* FALLTHROUGH */
default:
*dest++ = byte;
}
}
return dest;
}
static int rave_sp_write(struct rave_sp *sp, const u8 *data, u8 data_size)
{
const size_t checksum_length = sp->variant->checksum->length;
unsigned char frame[RAVE_SP_TX_BUFFER_SIZE];
unsigned char crc[RAVE_SP_CHECKSUM_SIZE];
unsigned char *dest = frame;
size_t length;
if (WARN_ON(checksum_length > sizeof(crc)))
return -ENOMEM;
if (WARN_ON(data_size > sizeof(frame)))
return -ENOMEM;
sp->variant->checksum->subroutine(data, data_size, crc);
*dest++ = RAVE_SP_STX;
dest = stuff(dest, data, data_size);
dest = stuff(dest, crc, checksum_length);
*dest++ = RAVE_SP_ETX;
length = dest - frame;
print_hex_dump_debug("rave-sp tx: ", DUMP_PREFIX_NONE,
16, 1, frame, length, false);
return serdev_device_write(sp->serdev, frame, length, HZ);
}
static u8 rave_sp_reply_code(u8 command)
{
/*
* There isn't a single rule that describes command code ->
* ACK code transformation, but, going through various
* versions of ICDs, there appear to be three distinct groups
* that can be described by simple transformation.
*/
switch (command) {
case 0xA0 ... 0xBE:
/*
* Commands implemented by firmware found in RDU1 and
* older devices all seem to obey the following rule
*/
return command + 0x20;
case 0xE0 ... 0xEF:
/*
* Events emitted by all versions of the firmare use
* least significant bit to get an ACK code
*/
return command | 0x01;
default:
/*
* Commands implemented by firmware found in RDU2 are
* similar to "old" commands, but they use slightly
* different offset
*/
return command + 0x40;
}
}
int rave_sp_exec(struct rave_sp *sp,
void *__data, size_t data_size,
void *reply_data, size_t reply_data_size)
{
struct rave_sp_reply reply = {
.data = reply_data,
.length = reply_data_size,
.received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
};
unsigned char *data = __data;
int command, ret = 0;
u8 ackid;
command = sp->variant->cmd.translate(data[0]);
if (command < 0)
return command;
ackid = atomic_inc_return(&sp->ackid);
reply.ackid = ackid;
reply.code = rave_sp_reply_code((u8)command),
mutex_lock(&sp->bus_lock);
mutex_lock(&sp->reply_lock);
sp->reply = &reply;
mutex_unlock(&sp->reply_lock);
data[0] = command;
data[1] = ackid;
rave_sp_write(sp, data, data_size);
if (!wait_for_completion_timeout(&reply.received, HZ)) {
dev_err(&sp->serdev->dev, "Command timeout\n");
ret = -ETIMEDOUT;
mutex_lock(&sp->reply_lock);
sp->reply = NULL;
mutex_unlock(&sp->reply_lock);
}
mutex_unlock(&sp->bus_lock);
return ret;
}
EXPORT_SYMBOL_GPL(rave_sp_exec);
static void rave_sp_receive_event(struct rave_sp *sp,
const unsigned char *data, size_t length)
{
u8 cmd[] = {
[0] = rave_sp_reply_code(data[0]),
[1] = data[1],
};
rave_sp_write(sp, cmd, sizeof(cmd));
blocking_notifier_call_chain(&sp->event_notifier_list,
rave_sp_action_pack(data[0], data[2]),
NULL);
}
static void rave_sp_receive_reply(struct rave_sp *sp,
const unsigned char *data, size_t length)
{
struct device *dev = &sp->serdev->dev;
struct rave_sp_reply *reply;
const size_t payload_length = length - 2;
mutex_lock(&sp->reply_lock);
reply = sp->reply;
if (reply) {
if (reply->code == data[0] && reply->ackid == data[1] &&
payload_length >= reply->length) {
/*
* We are relying on memcpy(dst, src, 0) to be a no-op
* when handling commands that have a no-payload reply
*/
memcpy(reply->data, &data[2], reply->length);
complete(&reply->received);
sp->reply = NULL;
} else {
dev_err(dev, "Ignoring incorrect reply\n");
dev_dbg(dev, "Code: expected = 0x%08x received = 0x%08x\n",
reply->code, data[0]);
dev_dbg(dev, "ACK ID: expected = 0x%08x received = 0x%08x\n",
reply->ackid, data[1]);
dev_dbg(dev, "Length: expected = %zu received = %zu\n",
reply->length, payload_length);
}
}
mutex_unlock(&sp->reply_lock);
}
static void rave_sp_receive_frame(struct rave_sp *sp,
const unsigned char *data,
size_t length)
{
const size_t checksum_length = sp->variant->checksum->length;
const size_t payload_length = length - checksum_length;
const u8 *crc_reported = &data[payload_length];
struct device *dev = &sp->serdev->dev;
u8 crc_calculated[RAVE_SP_CHECKSUM_SIZE];
if (unlikely(checksum_length > sizeof(crc_calculated))) {
dev_warn(dev, "Checksum too long, dropping\n");
return;
}
print_hex_dump_debug("rave-sp rx: ", DUMP_PREFIX_NONE,
16, 1, data, length, false);
if (unlikely(length <= checksum_length)) {
dev_warn(dev, "Dropping short frame\n");
return;
}
sp->variant->checksum->subroutine(data, payload_length,
crc_calculated);
if (memcmp(crc_calculated, crc_reported, checksum_length)) {
dev_warn(dev, "Dropping bad frame\n");
return;
}
if (rave_sp_id_is_event(data[0]))
rave_sp_receive_event(sp, data, length);
else
rave_sp_receive_reply(sp, data, length);
}
static int rave_sp_receive_buf(struct serdev_device *serdev,
const unsigned char *buf, size_t size)
{
struct device *dev = &serdev->dev;
struct rave_sp *sp = dev_get_drvdata(dev);
struct rave_sp_deframer *deframer = &sp->deframer;
const unsigned char *src = buf;
const unsigned char *end = buf + size;
while (src < end) {
const unsigned char byte = *src++;
switch (deframer->state) {
case RAVE_SP_EXPECT_SOF:
if (byte == RAVE_SP_STX)
deframer->state = RAVE_SP_EXPECT_DATA;
break;
case RAVE_SP_EXPECT_DATA:
/*
* Treat special byte values first
*/
switch (byte) {
case RAVE_SP_ETX:
rave_sp_receive_frame(sp,
deframer->data,
deframer->length);
/*
* Once we extracted a complete frame
* out of a stream, we call it done
* and proceed to bailing out while
* resetting the framer to initial
* state, regardless if we've consumed
* all of the stream or not.
*/
goto reset_framer;
case RAVE_SP_STX:
dev_warn(dev, "Bad frame: STX before ETX\n");
/*
* If we encounter second "start of
* the frame" marker before seeing
* corresponding "end of frame", we
* reset the framer and ignore both:
* frame started by first SOF and
* frame started by current SOF.
*
* NOTE: The above means that only the
* frame started by third SOF, sent
* after this one will have a chance
* to get throught.
*/
goto reset_framer;
case RAVE_SP_DLE:
deframer->state = RAVE_SP_EXPECT_ESCAPED_DATA;
/*
* If we encounter escape sequence we
* need to skip it and collect the
* byte that follows. We do it by
* forcing the next iteration of the
* encompassing while loop.
*/
continue;
}
/*
* For the rest of the bytes, that are not
* speical snoflakes, we do the same thing
* that we do to escaped data - collect it in
* deframer buffer
*/
/* FALLTHROUGH */
case RAVE_SP_EXPECT_ESCAPED_DATA:
if (deframer->length == sizeof(deframer->data)) {
dev_warn(dev, "Bad frame: Too long\n");
/*
* If the amount of data we've
* accumulated for current frame so
* far starts to exceed the capacity
* of deframer's buffer, there's
* nothing else we can do but to
* discard that data and start
* assemblying a new frame again
*/
goto reset_framer;
}
deframer->data[deframer->length++] = byte;
/*
* We've extracted out special byte, now we
* can go back to regular data collecting
*/
deframer->state = RAVE_SP_EXPECT_DATA;
break;
}
}
/*
* The only way to get out of the above loop and end up here
* is throught consuming all of the supplied data, so here we
* report that we processed it all.
*/
return size;
reset_framer:
/*
* NOTE: A number of codepaths that will drop us here will do
* so before consuming all 'size' bytes of the data passed by
* serdev layer. We rely on the fact that serdev layer will
* re-execute this handler with the remainder of the Rx bytes
* once we report actual number of bytes that we processed.
*/
deframer->state = RAVE_SP_EXPECT_SOF;
deframer->length = 0;
return src - buf;
}
static int rave_sp_rdu1_cmd_translate(enum rave_sp_command command)
{
if (command >= RAVE_SP_CMD_STATUS &&
command <= RAVE_SP_CMD_CONTROL_EVENTS)
return command;
return -EINVAL;
}
static int rave_sp_rdu2_cmd_translate(enum rave_sp_command command)
{
if (command >= RAVE_SP_CMD_GET_FIRMWARE_VERSION &&
command <= RAVE_SP_CMD_GET_GPIO_STATE)
return command;
if (command == RAVE_SP_CMD_REQ_COPPER_REV) {
/*
* As per RDU2 ICD 3.4.47 CMD_GET_COPPER_REV code is
* different from that for RDU1 and it is set to 0x28.
*/
return 0x28;
}
return rave_sp_rdu1_cmd_translate(command);
}
static int rave_sp_default_cmd_translate(enum rave_sp_command command)
{
/*
* All of the following command codes were taken from "Table :
* Communications Protocol Message Types" in section 3.3
* "MESSAGE TYPES" of Rave PIC24 ICD.
*/
switch (command) {
case RAVE_SP_CMD_GET_FIRMWARE_VERSION:
return 0x11;
case RAVE_SP_CMD_GET_BOOTLOADER_VERSION:
return 0x12;
case RAVE_SP_CMD_BOOT_SOURCE:
return 0x14;
case RAVE_SP_CMD_SW_WDT:
return 0x1C;
case RAVE_SP_CMD_PET_WDT:
return 0x1D;
case RAVE_SP_CMD_RESET:
return 0x1E;
case RAVE_SP_CMD_RESET_REASON:
return 0x1F;
case RAVE_SP_CMD_RMB_EEPROM:
return 0x20;
default:
return -EINVAL;
}
}
static const char *devm_rave_sp_version(struct device *dev,
struct rave_sp_version *version)
{
/*
* NOTE: The format string below uses %02d to display u16
* intentionally for the sake of backwards compatibility with
* legacy software.
*/
return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
version->hardware,
le16_to_cpu(version->major),
version->minor,
version->letter[0],
version->letter[1]);
}
static int rave_sp_rdu1_get_status(struct rave_sp *sp,
struct rave_sp_status *status)
{
u8 cmd[] = {
[0] = RAVE_SP_CMD_STATUS,
[1] = 0
};
return rave_sp_exec(sp, cmd, sizeof(cmd), status, sizeof(*status));
}
static int rave_sp_emulated_get_status(struct rave_sp *sp,
struct rave_sp_status *status)
{
u8 cmd[] = {
[0] = RAVE_SP_CMD_GET_FIRMWARE_VERSION,
[1] = 0,
};
int ret;
ret = rave_sp_exec(sp, cmd, sizeof(cmd), &status->firmware_version,
sizeof(status->firmware_version));
if (ret)
return ret;
cmd[0] = RAVE_SP_CMD_GET_BOOTLOADER_VERSION;
return rave_sp_exec(sp, cmd, sizeof(cmd), &status->bootloader_version,
sizeof(status->bootloader_version));
}
static int rave_sp_get_status(struct rave_sp *sp)
{
struct device *dev = &sp->serdev->dev;
struct rave_sp_status status;
const char *version;
int ret;
ret = sp->variant->cmd.get_status(sp, &status);
if (ret)
return ret;
version = devm_rave_sp_version(dev, &status.firmware_version);
if (!version)
return -ENOMEM;
sp->part_number_firmware = version;
version = devm_rave_sp_version(dev, &status.bootloader_version);
if (!version)
return -ENOMEM;
sp->part_number_bootloader = version;
return 0;
}
static const struct rave_sp_checksum rave_sp_checksum_8b2c = {
.length = 1,
.subroutine = csum_8b2c,
};
static const struct rave_sp_checksum rave_sp_checksum_ccitt = {
.length = 2,
.subroutine = csum_ccitt,
};
static const struct rave_sp_variant rave_sp_legacy = {
.checksum = &rave_sp_checksum_ccitt,
.cmd = {
.translate = rave_sp_default_cmd_translate,
.get_status = rave_sp_emulated_get_status,
},
};
static const struct rave_sp_variant rave_sp_rdu1 = {
.checksum = &rave_sp_checksum_8b2c,
.cmd = {
.translate = rave_sp_rdu1_cmd_translate,
.get_status = rave_sp_rdu1_get_status,
},
};
static const struct rave_sp_variant rave_sp_rdu2 = {
.checksum = &rave_sp_checksum_ccitt,
.cmd = {
.translate = rave_sp_rdu2_cmd_translate,
.get_status = rave_sp_emulated_get_status,
},
};
static const struct of_device_id rave_sp_dt_ids[] = {
{ .compatible = "zii,rave-sp-niu", .data = &rave_sp_legacy },
{ .compatible = "zii,rave-sp-mezz", .data = &rave_sp_legacy },
{ .compatible = "zii,rave-sp-esb", .data = &rave_sp_legacy },
{ .compatible = "zii,rave-sp-rdu1", .data = &rave_sp_rdu1 },
{ .compatible = "zii,rave-sp-rdu2", .data = &rave_sp_rdu2 },
{ /* sentinel */ }
};
static const struct serdev_device_ops rave_sp_serdev_device_ops = {
.receive_buf = rave_sp_receive_buf,
.write_wakeup = serdev_device_write_wakeup,
};
static int rave_sp_probe(struct serdev_device *serdev)
{
struct device *dev = &serdev->dev;
const char *unknown = "unknown\n";
struct rave_sp *sp;
u32 baud;
int ret;
if (of_property_read_u32(dev->of_node, "current-speed", &baud)) {
dev_err(dev,
"'current-speed' is not specified in device node\n");
return -EINVAL;
}
sp = devm_kzalloc(dev, sizeof(*sp), GFP_KERNEL);
if (!sp)
return -ENOMEM;
sp->serdev = serdev;
dev_set_drvdata(dev, sp);
sp->variant = of_device_get_match_data(dev);
if (!sp->variant)
return -ENODEV;
mutex_init(&sp->bus_lock);
mutex_init(&sp->reply_lock);
BLOCKING_INIT_NOTIFIER_HEAD(&sp->event_notifier_list);
serdev_device_set_client_ops(serdev, &rave_sp_serdev_device_ops);
ret = devm_serdev_device_open(dev, serdev);
if (ret)
return ret;
serdev_device_set_baudrate(serdev, baud);
serdev_device_set_flow_control(serdev, false);
ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
if (ret) {
dev_err(dev, "Failed to set parity\n");
return ret;
}
ret = rave_sp_get_status(sp);
if (ret) {
dev_warn(dev, "Failed to get firmware status: %d\n", ret);
sp->part_number_firmware = unknown;
sp->part_number_bootloader = unknown;
}
/*
* Those strings already have a \n embedded, so there's no
* need to have one in format string.
*/
dev_info(dev, "Firmware version: %s", sp->part_number_firmware);
dev_info(dev, "Bootloader version: %s", sp->part_number_bootloader);
return devm_of_platform_populate(dev);
}
MODULE_DEVICE_TABLE(of, rave_sp_dt_ids);
static struct serdev_device_driver rave_sp_drv = {
.probe = rave_sp_probe,
.driver = {
.name = "rave-sp",
.of_match_table = rave_sp_dt_ids,
},
};
module_serdev_device_driver(rave_sp_drv);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
MODULE_DESCRIPTION("RAVE SP core driver");
Reference in New Issue View Git Blame Copy Permalink