usb: typec: ucsi: ccg: add firmware flashing support

CCGx has two copies of the firmware in addition to the bootloader.
If the device is running FW1, FW2 can be updated with the new version.
Dual firmware mode allows the CCG device to stay in a PD contract and
support USB PD and Type-C functionality while a firmware update is in
progress.

First we read the currently flashed firmware version of both
primary and secondary firmware and then compare it with
version of firmware file to determine if flashing is required.

Command framework is added to support sending commands to CCGx
controller. We wait for response after sending the command and then
read the response from RAB_RESPONSE register.

Below commands are supported,
- ENTER_FLASHING
- RESET
- PDPORT_ENABLE
- JUMP_TO_BOOT
- FLASH_ROW_RW
- VALIDATE_FW

Command specific mutex lock is also added to sync between driver
and user threads.

PD port number information is added which is required while sending
PD_PORT_ENABLE command

Signed-off-by: Ajay Gupta <[e-mail]>
[ heikki: Added ABI documentation. ]
Signed-off-by: Heikki Krogerus <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/ABI/testing/sysfs-driver-ucsi-ccg

···
+What:		/sys/bus/i2c/drivers/ucsi_ccg/.../do_flash
+Date:		May 2019
+Contact:	Ajay Gupta <[e-mail]>
+Description:
+		Tell the driver for Cypress CCGx Type-C controller to attempt
+		firmware upgrade by writing [Yy1] to the file.

drivers/usb/typec/ucsi/ucsi_ccg.c

···
  */
 #include <linux/acpi.h>
 #include <linux/delay.h>
+#include <linux/firmware.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/pci.h>
···
 	FW1,    /* FW partition-1 (contains secondary fw) */
 	FW2,    /* FW partition-2 (contains primary fw) */
 	FW_INVALID,
+};
+
+#define CCGX_RAB_DEVICE_MODE			0x0000
+#define CCGX_RAB_INTR_REG			0x0006
+#define  DEV_INT				BIT(0)
+#define  PORT0_INT				BIT(1)
+#define  PORT1_INT				BIT(2)
+#define  UCSI_READ_INT				BIT(7)
+#define CCGX_RAB_JUMP_TO_BOOT			0x0007
+#define  TO_BOOT				'J'
+#define  TO_ALT_FW				'A'
+#define CCGX_RAB_RESET_REQ			0x0008
+#define  RESET_SIG				'R'
+#define  CMD_RESET_I2C				0x0
+#define  CMD_RESET_DEV				0x1
+#define CCGX_RAB_ENTER_FLASHING			0x000A
+#define  FLASH_ENTER_SIG			'P'
+#define CCGX_RAB_VALIDATE_FW			0x000B
+#define CCGX_RAB_FLASH_ROW_RW			0x000C
+#define  FLASH_SIG				'F'
+#define  FLASH_RD_CMD				0x0
+#define  FLASH_WR_CMD				0x1
+#define  FLASH_FWCT1_WR_CMD			0x2
+#define  FLASH_FWCT2_WR_CMD			0x3
+#define  FLASH_FWCT_SIG_WR_CMD			0x4
+#define CCGX_RAB_READ_ALL_VER			0x0010
+#define CCGX_RAB_READ_FW2_VER			0x0020
+#define CCGX_RAB_UCSI_CONTROL			0x0039
+#define CCGX_RAB_UCSI_CONTROL_START		BIT(0)
+#define CCGX_RAB_UCSI_CONTROL_STOP		BIT(1)
+#define CCGX_RAB_UCSI_DATA_BLOCK(offset)	(0xf000 | ((offset) & 0xff))
+#define REG_FLASH_RW_MEM        0x0200
+#define DEV_REG_IDX				CCGX_RAB_DEVICE_MODE
+#define CCGX_RAB_PDPORT_ENABLE			0x002C
+#define  PDPORT_1		BIT(0)
+#define  PDPORT_2		BIT(1)
+#define CCGX_RAB_RESPONSE			0x007E
+#define  ASYNC_EVENT				BIT(7)
+
+/* CCGx events & async msg codes */
+#define RESET_COMPLETE		0x80
+#define EVENT_INDEX		RESET_COMPLETE
+#define PORT_CONNECT_DET	0x84
+#define PORT_DISCONNECT_DET	0x85
+#define ROLE_SWAP_COMPELETE	0x87
+
+/* ccg firmware */
+#define CYACD_LINE_SIZE         527
+#define CCG4_ROW_SIZE           256
+#define FW1_METADATA_ROW        0x1FF
+#define FW2_METADATA_ROW        0x1FE
+#define FW_CFG_TABLE_SIG_SIZE	256
+
+static int secondary_fw_min_ver = 41;
+
+enum enum_flash_mode {
+	SECONDARY_BL,	/* update secondary using bootloader */
+	PRIMARY,	/* update primary using secondary */
+	SECONDARY,	/* update secondary using primary */
+	FLASH_NOT_NEEDED,	/* update not required */
+	FLASH_INVALID,
+};
+
+static const char * const ccg_fw_names[] = {
+	"ccg_boot.cyacd",
+	"ccg_primary.cyacd",
+	"ccg_secondary.cyacd"
 };
 
 struct ccg_dev_info {
···
 	struct version_format app;
 };
 
+struct fw_config_table {
+	u32 identity;
+	u16 table_size;
+	u8 fwct_version;
+	u8 is_key_change;
+	u8 guid[16];
+	struct version_format base;
+	struct version_format app;
+	u8 primary_fw_digest[32];
+	u32 key_exp_length;
+	u8 key_modulus[256];
+	u8 key_exp[4];
+};
+
+/* CCGx response codes */
+enum ccg_resp_code {
+	CMD_NO_RESP             = 0x00,
+	CMD_SUCCESS             = 0x02,
+	FLASH_DATA_AVAILABLE    = 0x03,
+	CMD_INVALID             = 0x05,
+	FLASH_UPDATE_FAIL       = 0x07,
+	INVALID_FW              = 0x08,
+	INVALID_ARG             = 0x09,
+	CMD_NOT_SUPPORT         = 0x0A,
+	TRANSACTION_FAIL        = 0x0C,
+	PD_CMD_FAIL             = 0x0D,
+	UNDEF_ERROR             = 0x0F,
+	INVALID_RESP		= 0x10,
+};
+
+#define CCG_EVENT_MAX	(EVENT_INDEX + 43)
+
+struct ccg_cmd {
+	u16 reg;
+	u32 data;
+	int len;
+	u32 delay; /* ms delay for cmd timeout  */
+};
+
+struct ccg_resp {
+	u8 code;
+	u8 length;
+};
+
 struct ucsi_ccg {
 	struct device *dev;
 	struct ucsi *ucsi;
···
 	struct ccg_dev_info info;
 	/* version info for boot, primary and secondary */
 	struct version_info version[FW2 + 1];
-};
+	/* CCG HPI communication flags */
+	unsigned long flags;
+#define RESET_PENDING	0
+#define DEV_CMD_PENDING	1
+	struct ccg_resp dev_resp;
+	u8 cmd_resp;
+	int port_num;
+	int irq;
+	struct work_struct work;
+	struct mutex lock; /* to sync between user and driver thread */
 
-#define CCGX_RAB_DEVICE_MODE			0x0000
-#define CCGX_RAB_INTR_REG			0x0006
-#define CCGX_RAB_READ_ALL_VER			0x0010
-#define CCGX_RAB_READ_FW2_VER			0x0020
-#define CCGX_RAB_UCSI_CONTROL			0x0039
-#define CCGX_RAB_UCSI_CONTROL_START		BIT(0)
-#define CCGX_RAB_UCSI_CONTROL_STOP		BIT(1)
-#define CCGX_RAB_UCSI_DATA_BLOCK(offset)	(0xf000 | ((offset) & 0xff))
+	/* fw build with vendor information */
+	u16 fw_build;
+};
 
 static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
 {
···
 	return 0;
 }
 
+static inline bool invalid_async_evt(int code)
+{
+	return (code >= CCG_EVENT_MAX) || (code < EVENT_INDEX);
+}
+
+static void ccg_process_response(struct ucsi_ccg *uc)
+{
+	struct device *dev = uc->dev;
+
+	if (uc->dev_resp.code & ASYNC_EVENT) {
+		if (uc->dev_resp.code == RESET_COMPLETE) {
+			if (test_bit(RESET_PENDING, &uc->flags))
+				uc->cmd_resp = uc->dev_resp.code;
+			get_fw_info(uc);
+		}
+		if (invalid_async_evt(uc->dev_resp.code))
+			dev_err(dev, "invalid async evt %d\n",
+				uc->dev_resp.code);
+	} else {
+		if (test_bit(DEV_CMD_PENDING, &uc->flags)) {
+			uc->cmd_resp = uc->dev_resp.code;
+			clear_bit(DEV_CMD_PENDING, &uc->flags);
+		} else {
+			dev_err(dev, "dev resp 0x%04x but no cmd pending\n",
+				uc->dev_resp.code);
+		}
+	}
+}
+
+static int ccg_read_response(struct ucsi_ccg *uc)
+{
+	unsigned long target = jiffies + msecs_to_jiffies(1000);
+	struct device *dev = uc->dev;
+	u8 intval;
+	int status;
+
+	/* wait for interrupt status to get updated */
+	do {
+		status = ccg_read(uc, CCGX_RAB_INTR_REG, &intval,
+				  sizeof(intval));
+		if (status < 0)
+			return status;
+
+		if (intval & DEV_INT)
+			break;
+		usleep_range(500, 600);
+	} while (time_is_after_jiffies(target));
+
+	if (time_is_before_jiffies(target)) {
+		dev_err(dev, "response timeout error\n");
+		return -ETIME;
+	}
+
+	status = ccg_read(uc, CCGX_RAB_RESPONSE, (u8 *)&uc->dev_resp,
+			  sizeof(uc->dev_resp));
+	if (status < 0)
+		return status;
+
+	status = ccg_write(uc, CCGX_RAB_INTR_REG, &intval, sizeof(intval));
+	if (status < 0)
+		return status;
+
+	return 0;
+}
+
+/* Caller must hold uc->lock */
+static int ccg_send_command(struct ucsi_ccg *uc, struct ccg_cmd *cmd)
+{
+	struct device *dev = uc->dev;
+	int ret;
+
+	switch (cmd->reg & 0xF000) {
+	case DEV_REG_IDX:
+		set_bit(DEV_CMD_PENDING, &uc->flags);
+		break;
+	default:
+		dev_err(dev, "invalid cmd register\n");
+		break;
+	}
+
+	ret = ccg_write(uc, cmd->reg, (u8 *)&cmd->data, cmd->len);
+	if (ret < 0)
+		return ret;
+
+	msleep(cmd->delay);
+
+	ret = ccg_read_response(uc);
+	if (ret < 0) {
+		dev_err(dev, "response read error\n");
+		switch (cmd->reg & 0xF000) {
+		case DEV_REG_IDX:
+			clear_bit(DEV_CMD_PENDING, &uc->flags);
+			break;
+		default:
+			dev_err(dev, "invalid cmd register\n");
+			break;
+		}
+		return -EIO;
+	}
+	ccg_process_response(uc);
+
+	return uc->cmd_resp;
+}
+
+static int ccg_cmd_enter_flashing(struct ucsi_ccg *uc)
+{
+	struct ccg_cmd cmd;
+	int ret;
+
+	cmd.reg = CCGX_RAB_ENTER_FLASHING;
+	cmd.data = FLASH_ENTER_SIG;
+	cmd.len = 1;
+	cmd.delay = 50;
+
+	mutex_lock(&uc->lock);
+
+	ret = ccg_send_command(uc, &cmd);
+
+	mutex_unlock(&uc->lock);
+
+	if (ret != CMD_SUCCESS) {
+		dev_err(uc->dev, "enter flashing failed ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ccg_cmd_reset(struct ucsi_ccg *uc)
+{
+	struct ccg_cmd cmd;
+	u8 *p;
+	int ret;
+
+	p = (u8 *)&cmd.data;
+	cmd.reg = CCGX_RAB_RESET_REQ;
+	p[0] = RESET_SIG;
+	p[1] = CMD_RESET_DEV;
+	cmd.len = 2;
+	cmd.delay = 5000;
+
+	mutex_lock(&uc->lock);
+
+	set_bit(RESET_PENDING, &uc->flags);
+
+	ret = ccg_send_command(uc, &cmd);
+	if (ret != RESET_COMPLETE)
+		goto err_clear_flag;
+
+	ret = 0;
+
+err_clear_flag:
+	clear_bit(RESET_PENDING, &uc->flags);
+
+	mutex_unlock(&uc->lock);
+
+	return ret;
+}
+
+static int ccg_cmd_port_control(struct ucsi_ccg *uc, bool enable)
+{
+	struct ccg_cmd cmd;
+	int ret;
+
+	cmd.reg = CCGX_RAB_PDPORT_ENABLE;
+	if (enable)
+		cmd.data = (uc->port_num == 1) ?
+			    PDPORT_1 : (PDPORT_1 | PDPORT_2);
+	else
+		cmd.data = 0x0;
+	cmd.len = 1;
+	cmd.delay = 10;
+
+	mutex_lock(&uc->lock);
+
+	ret = ccg_send_command(uc, &cmd);
+
+	mutex_unlock(&uc->lock);
+
+	if (ret != CMD_SUCCESS) {
+		dev_err(uc->dev, "port control failed ret=%d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int ccg_cmd_jump_boot_mode(struct ucsi_ccg *uc, int bl_mode)
+{
+	struct ccg_cmd cmd;
+	int ret;
+
+	cmd.reg = CCGX_RAB_JUMP_TO_BOOT;
+
+	if (bl_mode)
+		cmd.data = TO_BOOT;
+	else
+		cmd.data = TO_ALT_FW;
+
+	cmd.len = 1;
+	cmd.delay = 100;
+
+	mutex_lock(&uc->lock);
+
+	set_bit(RESET_PENDING, &uc->flags);
+
+	ret = ccg_send_command(uc, &cmd);
+	if (ret != RESET_COMPLETE)
+		goto err_clear_flag;
+
+	ret = 0;
+
+err_clear_flag:
+	clear_bit(RESET_PENDING, &uc->flags);
+
+	mutex_unlock(&uc->lock);
+
+	return ret;
+}
+
+static int
+ccg_cmd_write_flash_row(struct ucsi_ccg *uc, u16 row,
+			const void *data, u8 fcmd)
+{
+	struct i2c_client *client = uc->client;
+	struct ccg_cmd cmd;
+	u8 buf[CCG4_ROW_SIZE + 2];
+	u8 *p;
+	int ret;
+
+	/* Copy the data into the flash read/write memory. */
+	put_unaligned_le16(REG_FLASH_RW_MEM, buf);
+
+	memcpy(buf + 2, data, CCG4_ROW_SIZE);
+
+	mutex_lock(&uc->lock);
+
+	ret = i2c_master_send(client, buf, CCG4_ROW_SIZE + 2);
+	if (ret != CCG4_ROW_SIZE + 2) {
+		dev_err(uc->dev, "REG_FLASH_RW_MEM write fail %d\n", ret);
+		return ret < 0 ? ret : -EIO;
+	}
+
+	/* Use the FLASH_ROW_READ_WRITE register to trigger */
+	/* writing of data to the desired flash row */
+	p = (u8 *)&cmd.data;
+	cmd.reg = CCGX_RAB_FLASH_ROW_RW;
+	p[0] = FLASH_SIG;
+	p[1] = fcmd;
+	put_unaligned_le16(row, &p[2]);
+	cmd.len = 4;
+	cmd.delay = 50;
+	if (fcmd == FLASH_FWCT_SIG_WR_CMD)
+		cmd.delay += 400;
+	if (row == 510)
+		cmd.delay += 220;
+	ret = ccg_send_command(uc, &cmd);
+
+	mutex_unlock(&uc->lock);
+
+	if (ret != CMD_SUCCESS) {
+		dev_err(uc->dev, "write flash row failed ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ccg_cmd_validate_fw(struct ucsi_ccg *uc, unsigned int fwid)
+{
+	struct ccg_cmd cmd;
+	int ret;
+
+	cmd.reg = CCGX_RAB_VALIDATE_FW;
+	cmd.data = fwid;
+	cmd.len = 1;
+	cmd.delay = 500;
+
+	mutex_lock(&uc->lock);
+
+	ret = ccg_send_command(uc, &cmd);
+
+	mutex_unlock(&uc->lock);
+
+	if (ret != CMD_SUCCESS)
+		return ret;
+
+	return 0;
+}
+
+static bool ccg_check_vendor_version(struct ucsi_ccg *uc,
+				     struct version_format *app,
+				     struct fw_config_table *fw_cfg)
+{
+	struct device *dev = uc->dev;
+
+	/* Check if the fw build is for supported vendors */
+	if (le16_to_cpu(app->build) != uc->fw_build) {
+		dev_info(dev, "current fw is not from supported vendor\n");
+		return false;
+	}
+
+	/* Check if the new fw build is for supported vendors */
+	if (le16_to_cpu(fw_cfg->app.build) != uc->fw_build) {
+		dev_info(dev, "new fw is not from supported vendor\n");
+		return false;
+	}
+	return true;
+}
+
+static bool ccg_check_fw_version(struct ucsi_ccg *uc, const char *fw_name,
+				 struct version_format *app)
+{
+	const struct firmware *fw = NULL;
+	struct device *dev = uc->dev;
+	struct fw_config_table fw_cfg;
+	u32 cur_version, new_version;
+	bool is_later = false;
+
+	if (request_firmware(&fw, fw_name, dev) != 0) {
+		dev_err(dev, "error: Failed to open cyacd file %s\n", fw_name);
+		return false;
+	}
+
+	/*
+	 * check if signed fw
+	 * last part of fw image is fw cfg table and signature
+	 */
+	if (fw->size < sizeof(fw_cfg) + FW_CFG_TABLE_SIG_SIZE)
+		goto out_release_firmware;
+
+	memcpy((uint8_t *)&fw_cfg, fw->data + fw->size -
+	       sizeof(fw_cfg) - FW_CFG_TABLE_SIG_SIZE, sizeof(fw_cfg));
+
+	if (fw_cfg.identity != ('F' | 'W' << 8 | 'C' << 16 | 'T' << 24)) {
+		dev_info(dev, "not a signed image\n");
+		goto out_release_firmware;
+	}
+
+	/* compare input version with FWCT version */
+	cur_version = le16_to_cpu(app->build) | app->patch << 16 |
+			app->ver << 24;
+
+	new_version = le16_to_cpu(fw_cfg.app.build) | fw_cfg.app.patch << 16 |
+			fw_cfg.app.ver << 24;
+
+	if (!ccg_check_vendor_version(uc, app, &fw_cfg))
+		goto out_release_firmware;
+
+	if (new_version > cur_version)
+		is_later = true;
+
+out_release_firmware:
+	release_firmware(fw);
+	return is_later;
+}
+
+static int ccg_fw_update_needed(struct ucsi_ccg *uc,
+				enum enum_flash_mode *mode)
+{
+	struct device *dev = uc->dev;
+	int err;
+	struct version_info version[3];
+
+	err = ccg_read(uc, CCGX_RAB_DEVICE_MODE, (u8 *)(&uc->info),
+		       sizeof(uc->info));
+	if (err) {
+		dev_err(dev, "read device mode failed\n");
+		return err;
+	}
+
+	err = ccg_read(uc, CCGX_RAB_READ_ALL_VER, (u8 *)version,
+		       sizeof(version));
+	if (err) {
+		dev_err(dev, "read device mode failed\n");
+		return err;
+	}
+
+	if (memcmp(&version[FW1], "\0\0\0\0\0\0\0\0",
+		   sizeof(struct version_info)) == 0) {
+		dev_info(dev, "secondary fw is not flashed\n");
+		*mode = SECONDARY_BL;
+	} else if (le16_to_cpu(version[FW1].base.build) <
+		secondary_fw_min_ver) {
+		dev_info(dev, "secondary fw version is too low (< %d)\n",
+			 secondary_fw_min_ver);
+		*mode = SECONDARY;
+	} else if (memcmp(&version[FW2], "\0\0\0\0\0\0\0\0",
+		   sizeof(struct version_info)) == 0) {
+		dev_info(dev, "primary fw is not flashed\n");
+		*mode = PRIMARY;
+	} else if (ccg_check_fw_version(uc, ccg_fw_names[PRIMARY],
+		   &version[FW2].app)) {
+		dev_info(dev, "found primary fw with later version\n");
+		*mode = PRIMARY;
+	} else {
+		dev_info(dev, "secondary and primary fw are the latest\n");
+		*mode = FLASH_NOT_NEEDED;
+	}
+	return 0;
+}
+
+static int do_flash(struct ucsi_ccg *uc, enum enum_flash_mode mode)
+{
+	struct device *dev = uc->dev;
+	const struct firmware *fw = NULL;
+	const char *p, *s;
+	const char *eof;
+	int err, row, len, line_sz, line_cnt = 0;
+	unsigned long start_time = jiffies;
+	struct fw_config_table  fw_cfg;
+	u8 fw_cfg_sig[FW_CFG_TABLE_SIG_SIZE];
+	u8 *wr_buf;
+
+	err = request_firmware(&fw, ccg_fw_names[mode], dev);
+	if (err) {
+		dev_err(dev, "request %s failed err=%d\n",
+			ccg_fw_names[mode], err);
+		return err;
+	}
+
+	if (((uc->info.mode & CCG_DEVINFO_FWMODE_MASK) >>
+			CCG_DEVINFO_FWMODE_SHIFT) == FW2) {
+		err = ccg_cmd_port_control(uc, false);
+		if (err < 0)
+			goto release_fw;
+		err = ccg_cmd_jump_boot_mode(uc, 0);
+		if (err < 0)
+			goto release_fw;
+	}
+
+	eof = fw->data + fw->size;
+
+	/*
+	 * check if signed fw
+	 * last part of fw image is fw cfg table and signature
+	 */
+	if (fw->size < sizeof(fw_cfg) + sizeof(fw_cfg_sig))
+		goto not_signed_fw;
+
+	memcpy((uint8_t *)&fw_cfg, fw->data + fw->size -
+	       sizeof(fw_cfg) - sizeof(fw_cfg_sig), sizeof(fw_cfg));
+
+	if (fw_cfg.identity != ('F' | ('W' << 8) | ('C' << 16) | ('T' << 24))) {
+		dev_info(dev, "not a signed image\n");
+		goto not_signed_fw;
+	}
+	eof = fw->data + fw->size - sizeof(fw_cfg) - sizeof(fw_cfg_sig);
+
+	memcpy((uint8_t *)&fw_cfg_sig,
+	       fw->data + fw->size - sizeof(fw_cfg_sig), sizeof(fw_cfg_sig));
+
+	/* flash fw config table and signature first */
+	err = ccg_cmd_write_flash_row(uc, 0, (u8 *)&fw_cfg,
+				      FLASH_FWCT1_WR_CMD);
+	if (err)
+		goto release_fw;
+
+	err = ccg_cmd_write_flash_row(uc, 0, (u8 *)&fw_cfg + CCG4_ROW_SIZE,
+				      FLASH_FWCT2_WR_CMD);
+	if (err)
+		goto release_fw;
+
+	err = ccg_cmd_write_flash_row(uc, 0, &fw_cfg_sig,
+				      FLASH_FWCT_SIG_WR_CMD);
+	if (err)
+		goto release_fw;
+
+not_signed_fw:
+	wr_buf = kzalloc(CCG4_ROW_SIZE + 4, GFP_KERNEL);
+	if (!wr_buf)
+		return -ENOMEM;
+
+	err = ccg_cmd_enter_flashing(uc);
+	if (err)
+		goto release_mem;
+
+	/*****************************************************************
+	 * CCG firmware image (.cyacd) file line format
+	 *
+	 * :00rrrrllll[dd....]cc/r/n
+	 *
+	 * :00   header
+	 * rrrr is row number to flash				(4 char)
+	 * llll is data len to flash				(4 char)
+	 * dd   is a data field represents one byte of data	(512 char)
+	 * cc   is checksum					(2 char)
+	 * \r\n newline
+	 *
+	 * Total length: 3 + 4 + 4 + 512 + 2 + 2 = 527
+	 *
+	 *****************************************************************/
+
+	p = strnchr(fw->data, fw->size, ':');
+	while (p < eof) {
+		s = strnchr(p + 1, eof - p - 1, ':');
+
+		if (!s)
+			s = eof;
+
+		line_sz = s - p;
+
+		if (line_sz != CYACD_LINE_SIZE) {
+			dev_err(dev, "Bad FW format line_sz=%d\n", line_sz);
+			err =  -EINVAL;
+			goto release_mem;
+		}
+
+		if (hex2bin(wr_buf, p + 3, CCG4_ROW_SIZE + 4)) {
+			err =  -EINVAL;
+			goto release_mem;
+		}
+
+		row = get_unaligned_be16(wr_buf);
+		len = get_unaligned_be16(&wr_buf[2]);
+
+		if (len != CCG4_ROW_SIZE) {
+			err =  -EINVAL;
+			goto release_mem;
+		}
+
+		err = ccg_cmd_write_flash_row(uc, row, wr_buf + 4,
+					      FLASH_WR_CMD);
+		if (err)
+			goto release_mem;
+
+		line_cnt++;
+		p = s;
+	}
+
+	dev_info(dev, "total %d row flashed. time: %dms\n",
+		 line_cnt, jiffies_to_msecs(jiffies - start_time));
+
+	err = ccg_cmd_validate_fw(uc, (mode == PRIMARY) ? FW2 :  FW1);
+	if (err)
+		dev_err(dev, "%s validation failed err=%d\n",
+			(mode == PRIMARY) ? "FW2" :  "FW1", err);
+	else
+		dev_info(dev, "%s validated\n",
+			 (mode == PRIMARY) ? "FW2" :  "FW1");
+
+	err = ccg_cmd_port_control(uc, false);
+	if (err < 0)
+		goto release_mem;
+
+	err = ccg_cmd_reset(uc);
+	if (err < 0)
+		goto release_mem;
+
+	err = ccg_cmd_port_control(uc, true);
+	if (err < 0)
+		goto release_mem;
+
+release_mem:
+	kfree(wr_buf);
+
+release_fw:
+	release_firmware(fw);
+	return err;
+}
+
+/*******************************************************************************
+ * CCG4 has two copies of the firmware in addition to the bootloader.
+ * If the device is running FW1, FW2 can be updated with the new version.
+ * Dual firmware mode allows the CCG device to stay in a PD contract and support
+ * USB PD and Type-C functionality while a firmware update is in progress.
+ ******************************************************************************/
+static int ccg_fw_update(struct ucsi_ccg *uc, enum enum_flash_mode flash_mode)
+{
+	int err;
+
+	while (flash_mode != FLASH_NOT_NEEDED) {
+		err = do_flash(uc, flash_mode);
+		if (err < 0)
+			return err;
+		err = ccg_fw_update_needed(uc, &flash_mode);
+		if (err < 0)
+			return err;
+	}
+	dev_info(uc->dev, "CCG FW update successful\n");
+
+	return err;
+}
+
+static int ccg_restart(struct ucsi_ccg *uc)
+{
+	struct device *dev = uc->dev;
+	int status;
+
+	status = ucsi_ccg_init(uc);
+	if (status < 0) {
+		dev_err(dev, "ucsi_ccg_start fail, err=%d\n", status);
+		return status;
+	}
+
+	status = request_threaded_irq(uc->irq, NULL, ccg_irq_handler,
+				      IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
+				      dev_name(dev), uc);
+	if (status < 0) {
+		dev_err(dev, "request_threaded_irq failed - %d\n", status);
+		return status;
+	}
+
+	uc->ucsi = ucsi_register_ppm(dev, &uc->ppm);
+	if (IS_ERR(uc->ucsi)) {
+		dev_err(uc->dev, "ucsi_register_ppm failed\n");
+		return PTR_ERR(uc->ucsi);
+	}
+
+	return 0;
+}
+
+static void ccg_update_firmware(struct work_struct *work)
+{
+	struct ucsi_ccg *uc = container_of(work, struct ucsi_ccg, work);
+	enum enum_flash_mode flash_mode;
+	int status;
+
+	status = ccg_fw_update_needed(uc, &flash_mode);
+	if (status < 0)
+		return;
+
+	if (flash_mode != FLASH_NOT_NEEDED) {
+		ucsi_unregister_ppm(uc->ucsi);
+		free_irq(uc->irq, uc);
+
+		ccg_fw_update(uc, flash_mode);
+		ccg_restart(uc);
+	}
+}
+
+static ssize_t do_flash_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t n)
+{
+	struct ucsi_ccg *uc = i2c_get_clientdata(to_i2c_client(dev));
+	bool flash;
+
+	if (kstrtobool(buf, &flash))
+		return -EINVAL;
+
+	if (!flash)
+		return n;
+
+	if (uc->fw_build == 0x0) {
+		dev_err(dev, "fail to flash FW due to missing FW build info\n");
+		return -EINVAL;
+	}
+
+	schedule_work(&uc->work);
+	return n;
+}
+
+static DEVICE_ATTR_WO(do_flash);
+
+static struct attribute *ucsi_ccg_sysfs_attrs[] = {
+	&dev_attr_do_flash.attr,
+	NULL,
+};
+
+static struct attribute_group ucsi_ccg_attr_group = {
+	.attrs = ucsi_ccg_sysfs_attrs,
+};
+
 static int ucsi_ccg_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
···
 	uc->ppm.sync = ucsi_ccg_sync;
 	uc->dev = dev;
 	uc->client = client;
+	mutex_init(&uc->lock);
+	INIT_WORK(&uc->work, ccg_update_firmware);
+
+	/* Only fail FW flashing when FW build information is not provided */
+	status = device_property_read_u16(dev, "ccgx,firmware-build",
+					  &uc->fw_build);
+	if (status)
+		dev_err(uc->dev, "failed to get FW build information\n");
 
 	/* reset ccg device and initialize ucsi */
 	status = ucsi_ccg_init(uc);
···
 		return status;
 	}
 
-	status = devm_request_threaded_irq(dev, client->irq, NULL,
-					   ccg_irq_handler,
-					   IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
-					   dev_name(dev), uc);
+	uc->port_num = 1;
+
+	if (uc->info.mode & CCG_DEVINFO_PDPORTS_MASK)
+		uc->port_num++;
+
+	status = request_threaded_irq(client->irq, NULL, ccg_irq_handler,
+				      IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
+				      dev_name(dev), uc);
 	if (status < 0) {
 		dev_err(uc->dev, "request_threaded_irq failed - %d\n", status);
 		return status;
 	}
+
+	uc->irq = client->irq;
 
 	uc->ucsi = ucsi_register_ppm(dev, &uc->ppm);
 	if (IS_ERR(uc->ucsi)) {
···
 	}
 
 	i2c_set_clientdata(client, uc);
+
+	status = sysfs_create_group(&uc->dev->kobj, &ucsi_ccg_attr_group);
+	if (status)
+		dev_err(uc->dev, "cannot create sysfs group: %d\n", status);
+
 	return 0;
 }
 
···
 {
 	struct ucsi_ccg *uc = i2c_get_clientdata(client);
 
+	cancel_work_sync(&uc->work);
 	ucsi_unregister_ppm(uc->ucsi);
+	free_irq(uc->irq, uc);
+	sysfs_remove_group(&uc->dev->kobj, &ucsi_ccg_attr_group);
 
 	return 0;
 }