Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 843 insertions, 0 deletions

diff --git a/drivers/mfd/rave-sp.c b/drivers/mfd/rave-sp.c
new file mode 100644
index 0000000000..da50eba100
--- /dev/null
+++ b/drivers/mfd/rave-sp.c
@@ -0,0 +1,843 @@
+// 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_platform.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
+ * @received:   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");