// 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 <common.h>
#include <init.h>
#include <of_device.h>
#include <asm/unaligned.h>
#include <linux/crc-ccitt.h>
#include <linux/mfd/rave-sp.h>
#define DUMP_PREFIX_NONE 0
/*
* 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_SIZE 2 /* Worst case scenario on RDU2 */
/*
* 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)
#define RAVE_SP_IPADDR_INVALID U32_MAX
/**
* 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;
bool received;
};
/**
* struct rave_sp_checksum - Variant specific checksum implementation details
*
* @length: Caculated 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;
#define RAVE_SP_STATUS_GS_FIRMWARE_MODE BIT(1)
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 device_d dev;
struct serdev_device *serdev;
struct rave_sp_deframer deframer;
unsigned int ackid;
struct rave_sp_reply *reply;
const struct rave_sp_variant *variant;
const char *part_number_firmware;
const char *part_number_bootloader;
IPaddr_t ipaddr;
IPaddr_t netmask;
};
static bool rave_sp_id_is_event(u8 code)
{
return (code & 0xF0) == RAVE_SP_EVNT_BASE;
}
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;
if (IS_ENABLED(DEBUG))
print_hex_dump(0, "rave-sp tx: ", DUMP_PREFIX_NONE,
16, 1, frame, length, false);
return serdev_device_write(sp->serdev, frame, length, SECOND);
}
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 device_d *dev = sp->serdev->dev;
struct rave_sp_reply reply = {
.data = reply_data,
.length = reply_data_size,
.received = false,
};
unsigned char *data = __data;
int command, ret = 0;
u8 ackid;
command = sp->variant->cmd.translate(data[0]);
if (command < 0)
return command;
ackid = sp->ackid++;
reply.ackid = ackid;
reply.code = rave_sp_reply_code((u8)command),
sp->reply = &reply;
data[0] = command;
data[1] = ackid;
rave_sp_write(sp, data, data_size);
/*
* is_timeout will implicitly poll serdev via poller
* infrastructure
*/
ret = wait_on_timeout(SECOND, reply.received);
if (ret) {
dev_err(dev, "Command timeout\n");
sp->reply = NULL;
}
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],
};
/*
* The only thing we do for event, in case we get one, is to
* acknowledge it to prevent RAVE SP from spamming us
*/
rave_sp_write(sp, cmd, sizeof(cmd));
}
static void rave_sp_receive_reply(struct rave_sp *sp,
const unsigned char *data, size_t length)
{
struct device_d *dev = sp->serdev->dev;
struct rave_sp_reply *reply;
const size_t payload_length = length - 2;
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);
reply->received = true;
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);
}
}
}
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_d *dev = sp->serdev->dev;
u8 crc_calculated[checksum_length];
if (IS_ENABLED(DEBUG))
print_hex_dump(0, "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_d *dev = serdev->dev;
struct rave_sp *sp = dev->priv;
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_BOOTLOADER:
return 0x2A;
case RAVE_SP_CMD_RMB_EEPROM:
return 0x20;
default:
return -EINVAL;
}
}
static const char *devm_rave_sp_version(struct device_d *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 basprintf("%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_d *dev = sp->serdev->dev;
struct rave_sp_status status;
const char *mode;
int ret;
ret = sp->variant->cmd.get_status(sp, &status);
if (ret)
return ret;
if (status.general_status & RAVE_SP_STATUS_GS_FIRMWARE_MODE)
mode = "Application";
else
mode = "Bootloader";
dev_info(dev, "Device is in %s mode\n", mode);
sp->part_number_firmware = devm_rave_sp_version(dev,
&status.firmware_version);
sp->part_number_bootloader = devm_rave_sp_version(dev,
&status.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 __maybe_unused 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 int rave_sp_req_ip_addr(struct param_d *p, void *context)
{
struct rave_sp *sp = context;
u8 cmd[] = {
[0] = RAVE_SP_CMD_REQ_IP_ADDR,
[1] = 0,
[2] = 0, /* FIXME: Support for RJU? */
[3] = 0, /* Add support for IPs other than "self" */
};
struct {
__le32 ipaddr;
__le32 netmask;
} __packed rsp;
int ret;
/*
* We only query RAVE SP device for IP/Netmask once, after
* that we just "serve" cached data.
*/
if (sp->ipaddr != RAVE_SP_IPADDR_INVALID)
return 0;
ret = rave_sp_exec(sp, &cmd, sizeof(cmd), &rsp, sizeof(rsp));
if (ret < 0)
return ret;
sp->ipaddr = le32_to_cpu(rsp.ipaddr);
sp->netmask = le32_to_cpu(rsp.netmask);
return 0;
}
static int rave_sp_add_params(struct rave_sp *sp)
{
struct device_d *dev = &sp->dev;
struct param_d *p;
int ret;
dev->parent = sp->serdev->dev;
dev_set_name(dev, "sp");
dev->id = DEVICE_ID_SINGLE;
ret = register_device(dev);
if (ret)
return ret;
p = dev_add_param_ip(dev, "ipaddr", NULL, rave_sp_req_ip_addr,
&sp->ipaddr, sp);
if (IS_ERR(p))
return PTR_ERR(p);
p = dev_add_param_ip(dev, "netmask", NULL, rave_sp_req_ip_addr,
&sp->netmask, sp);
if (IS_ERR(p))
return PTR_ERR(p);
return 0;
}
static int rave_sp_probe(struct device_d *dev)
{
struct serdev_device *serdev = to_serdev_device(dev->parent);
struct rave_sp *sp;
u32 baud;
int ret;
if (of_property_read_u32(dev->device_node, "current-speed", &baud)) {
dev_err(dev,
"'current-speed' is not specified in device node\n");
return -EINVAL;
}
sp = xzalloc(sizeof(*sp));
sp->serdev = serdev;
sp->ipaddr = RAVE_SP_IPADDR_INVALID;
dev->priv = sp;
serdev->dev = dev;
serdev->receive_buf = rave_sp_receive_buf;
serdev->polling_interval = 500 * MSECOND;
/*
* We have to set polling window to 200ms initially in order
* to avoid timing out on get_status below when coming out of
* power-cycle induced reset. It's adjusted right after
*/
serdev->polling_window = 200 * MSECOND;
sp->variant = of_device_get_match_data(dev);
if (!sp->variant)
return -ENODEV;
ret = serdev_device_open(serdev);
if (ret)
return ret;
serdev_device_set_baudrate(serdev, baud);
ret = rave_sp_get_status(sp);
if (ret) {
dev_warn(dev, "Failed to get firmware status: %d\n", ret);
return ret;
}
/*
* 10ms is just a setting that was arrived at empirically when
* trying to make sure that EEPROM or MAC address access
* commnads to not time out.
*/
serdev->polling_window = 10 * MSECOND;
/*
* 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);
ret = rave_sp_add_params(sp);
if (ret) {
dev_err(dev, "Failed to add parameters to RAVE SP\n");
return ret;
}
return of_platform_populate(dev->device_node, NULL, dev);
}
static struct driver_d rave_sp_drv = {
.name = "rave-sp",
.probe = rave_sp_probe,
.of_compatible = DRV_OF_COMPAT(rave_sp_dt_ids),
};
console_platform_driver(rave_sp_drv);
