text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * Copyright 2015-2017 Google, Inc
   *
   * USB Type-C Port Controller Interface.
   */
  
  #include <linux/delay.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/i2c.h>
  #include <linux/interrupt.h>
  #include <linux/property.h>
  #include <linux/regmap.h>
  #include <linux/usb/pd.h>
  #include <linux/usb/tcpm.h>
  #include <linux/usb/typec.h>
  
  #include "tcpci.h"
  
  #define	PD_RETRY_COUNT_DEFAULT			3
  #define	PD_RETRY_COUNT_3_0_OR_HIGHER		2
  #define	AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV	3500
  #define	VSINKPD_MIN_IR_DROP_MV			750
  #define	VSRC_NEW_MIN_PERCENT			95
  #define	VSRC_VALID_MIN_MV			500
  #define	VPPS_NEW_MIN_PERCENT			95
  #define	VPPS_VALID_MIN_MV			100
  #define	VSINKDISCONNECT_PD_MIN_PERCENT		90
  
  #define tcpc_presenting_rd(reg, cc) \
  	(!(TCPC_ROLE_CTRL_DRP & (reg)) && \
  	 (((reg) & (TCPC_ROLE_CTRL_## cc ##_MASK << TCPC_ROLE_CTRL_## cc ##_SHIFT)) == \
  	  (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_## cc ##_SHIFT)))
  
  struct tcpci {
  	struct device *dev;
  
  	struct tcpm_port *port;
  
  	struct regmap *regmap;
  
  	bool controls_vbus;
  
  	struct tcpc_dev tcpc;
  	struct tcpci_data *data;
  };
  
  struct tcpci_chip {
  	struct tcpci *tcpci;
  	struct tcpci_data data;
  };
  
  struct tcpm_port *tcpci_get_tcpm_port(struct tcpci *tcpci)
  {
  	return tcpci->port;
  }
  EXPORT_SYMBOL_GPL(tcpci_get_tcpm_port);
  
  static inline struct tcpci *tcpc_to_tcpci(struct tcpc_dev *tcpc)
  {
  	return container_of(tcpc, struct tcpci, tcpc);
  }
  
  static int tcpci_read16(struct tcpci *tcpci, unsigned int reg, u16 *val)
  {
  	return regmap_raw_read(tcpci->regmap, reg, val, sizeof(u16));
  }
  
  static int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val)
  {
  	return regmap_raw_write(tcpci->regmap, reg, &val, sizeof(u16));
  }
  
  static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg;
  	int ret;
  
  	switch (cc) {
  	case TYPEC_CC_RA:
  		reg = (TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			(TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC2_SHIFT);
  		break;
  	case TYPEC_CC_RD:
  		reg = (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			(TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
  		break;
  	case TYPEC_CC_RP_DEF:
  		reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			(TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
  			(TCPC_ROLE_CTRL_RP_VAL_DEF <<
  			 TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  		break;
  	case TYPEC_CC_RP_1_5:
  		reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			(TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
  			(TCPC_ROLE_CTRL_RP_VAL_1_5 <<
  			 TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  		break;
  	case TYPEC_CC_RP_3_0:
  		reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			(TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
  			(TCPC_ROLE_CTRL_RP_VAL_3_0 <<
  			 TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  		break;
  	case TYPEC_CC_OPEN:
  	default:
  		reg = (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			(TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC2_SHIFT);
  		break;
  	}
  
  	ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  static int tcpci_apply_rc(struct tcpc_dev *tcpc, enum typec_cc_status cc,
  			  enum typec_cc_polarity polarity)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg;
  	int ret;
  
  	ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * APPLY_RC state is when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and vbus autodischarge on
  	 * disconnect is disabled. Bail out when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2.
  	 */
  	if (((reg & (TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT)) >>
  	     TCPC_ROLE_CTRL_CC2_SHIFT) !=
  	    ((reg & (TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT)) >>
  	     TCPC_ROLE_CTRL_CC1_SHIFT))
  		return 0;
  
  	return regmap_update_bits(tcpci->regmap, TCPC_ROLE_CTRL, polarity == TYPEC_POLARITY_CC1 ?
  				  TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT :
  				  TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT,
  				  TCPC_ROLE_CTRL_CC_OPEN);
  }
  
  static int tcpci_start_toggling(struct tcpc_dev *tcpc,
  				enum typec_port_type port_type,
  				enum typec_cc_status cc)
  {
  	int ret;
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg = TCPC_ROLE_CTRL_DRP;
  
  	if (port_type != TYPEC_PORT_DRP)
  		return -EOPNOTSUPP;
  
  	/* Handle vendor drp toggling */
  	if (tcpci->data->start_drp_toggling) {
  		ret = tcpci->data->start_drp_toggling(tcpci, tcpci->data, cc);
  		if (ret < 0)
  			return ret;
  	}
  
  	switch (cc) {
  	default:
  	case TYPEC_CC_RP_DEF:
  		reg |= (TCPC_ROLE_CTRL_RP_VAL_DEF <<
  			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  		break;
  	case TYPEC_CC_RP_1_5:
  		reg |= (TCPC_ROLE_CTRL_RP_VAL_1_5 <<
  			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  		break;
  	case TYPEC_CC_RP_3_0:
  		reg |= (TCPC_ROLE_CTRL_RP_VAL_3_0 <<
  			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
  		break;
  	}
  
  	if (cc == TYPEC_CC_RD)
  		reg |= (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			   (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
  	else
  		reg |= (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
  			   (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT);
  	ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
  	if (ret < 0)
  		return ret;
  	return regmap_write(tcpci->regmap, TCPC_COMMAND,
  			    TCPC_CMD_LOOK4CONNECTION);
  }
  
  static enum typec_cc_status tcpci_to_typec_cc(unsigned int cc, bool sink)
  {
  	switch (cc) {
  	case 0x1:
  		return sink ? TYPEC_CC_RP_DEF : TYPEC_CC_RA;
  	case 0x2:
  		return sink ? TYPEC_CC_RP_1_5 : TYPEC_CC_RD;
  	case 0x3:
  		if (sink)
  			return TYPEC_CC_RP_3_0;
  		fallthrough;
  	case 0x0:
  	default:
  		return TYPEC_CC_OPEN;
  	}
  }
  
  static int tcpci_get_cc(struct tcpc_dev *tcpc,
  			enum typec_cc_status *cc1, enum typec_cc_status *cc2)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg, role_control;
  	int ret;
  
  	ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &role_control);
  	if (ret < 0)
  		return ret;
  
  	ret = regmap_read(tcpci->regmap, TCPC_CC_STATUS, &reg);
  	if (ret < 0)
  		return ret;
  
  	*cc1 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC1_SHIFT) &
  				 TCPC_CC_STATUS_CC1_MASK,
  				 reg & TCPC_CC_STATUS_TERM ||
  				 tcpc_presenting_rd(role_control, CC1));
  	*cc2 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC2_SHIFT) &
  				 TCPC_CC_STATUS_CC2_MASK,
  				 reg & TCPC_CC_STATUS_TERM ||
  				 tcpc_presenting_rd(role_control, CC2));
  
  	return 0;
  }
  
  static int tcpci_set_polarity(struct tcpc_dev *tcpc,
  			      enum typec_cc_polarity polarity)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg;
  	int ret;
  	enum typec_cc_status cc1, cc2;
  
  	/* Obtain Rp setting from role control */
  	ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
  	if (ret < 0)
  		return ret;
  
  	ret = tcpci_get_cc(tcpc, &cc1, &cc2);
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * When port has drp toggling enabled, ROLE_CONTROL would only have the initial
  	 * terminations for the toggling and does not indicate the final cc
  	 * terminations when ConnectionResult is 0 i.e. drp toggling stops and
  	 * the connection is resolved. Infer port role from TCPC_CC_STATUS based on the
  	 * terminations seen. The port role is then used to set the cc terminations.
  	 */
  	if (reg & TCPC_ROLE_CTRL_DRP) {
  		/* Disable DRP for the OPEN setting to take effect */
  		reg = reg & ~TCPC_ROLE_CTRL_DRP;
  
  		if (polarity == TYPEC_POLARITY_CC2) {
  			reg &= ~(TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT);
  			/* Local port is source */
  			if (cc2 == TYPEC_CC_RD)
  				/* Role control would have the Rp setting when DRP was enabled */
  				reg |= TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT;
  			else
  				reg |= TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT;
  		} else {
  			reg &= ~(TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT);
  			/* Local port is source */
  			if (cc1 == TYPEC_CC_RD)
  				/* Role control would have the Rp setting when DRP was enabled */
  				reg |= TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT;
  			else
  				reg |= TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT;
  		}
  	}
  
  	if (polarity == TYPEC_POLARITY_CC2)
  		reg |= TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT;
  	else
  		reg |= TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC2_SHIFT;
  	ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
  	if (ret < 0)
  		return ret;
  
  	return regmap_write(tcpci->regmap, TCPC_TCPC_CTRL,
  			   (polarity == TYPEC_POLARITY_CC2) ?
  			   TCPC_TCPC_CTRL_ORIENTATION : 0);
  }
  
  static void tcpci_set_partner_usb_comm_capable(struct tcpc_dev *tcpc, bool capable)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  
  	if (tcpci->data->set_partner_usb_comm_capable)
  		tcpci->data->set_partner_usb_comm_capable(tcpci, tcpci->data, capable);
  }
  
  static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	int ret;
  
  	/* Handle vendor set vconn */
  	if (tcpci->data->set_vconn) {
  		ret = tcpci->data->set_vconn(tcpci, tcpci->data, enable);
  		if (ret < 0)
  			return ret;
  	}
  
  	return regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL,
  				TCPC_POWER_CTRL_VCONN_ENABLE,
  				enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
  }
  
  static int tcpci_enable_auto_vbus_discharge(struct tcpc_dev *dev, bool enable)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(dev);
  	int ret;
  
  	ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_POWER_CTRL_AUTO_DISCHARGE,
  				 enable ? TCPC_POWER_CTRL_AUTO_DISCHARGE : 0);
  	return ret;
  }
  
  static int tcpci_set_auto_vbus_discharge_threshold(struct tcpc_dev *dev, enum typec_pwr_opmode mode,
  						   bool pps_active, u32 requested_vbus_voltage_mv)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(dev);
  	unsigned int pwr_ctrl, threshold = 0;
  	int ret;
  
  	/*
  	 * Indicates that vbus is going to go away due PR_SWAP, hard reset etc.
  	 * Do not discharge vbus here.
  	 */
  	if (requested_vbus_voltage_mv == 0)
  		goto write_thresh;
  
  	ret = regmap_read(tcpci->regmap, TCPC_POWER_CTRL, &pwr_ctrl);
  	if (ret < 0)
  		return ret;
  
  	if (pwr_ctrl & TCPC_FAST_ROLE_SWAP_EN) {
  		/* To prevent disconnect when the source is fast role swap is capable. */
  		threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;
  	} else if (mode == TYPEC_PWR_MODE_PD) {
  		if (pps_active)
  			threshold = ((VPPS_NEW_MIN_PERCENT * requested_vbus_voltage_mv / 100) -
  				     VSINKPD_MIN_IR_DROP_MV - VPPS_VALID_MIN_MV) *
  				     VSINKDISCONNECT_PD_MIN_PERCENT / 100;
  		else
  			threshold = ((VSRC_NEW_MIN_PERCENT * requested_vbus_voltage_mv / 100) -
  				     VSINKPD_MIN_IR_DROP_MV - VSRC_VALID_MIN_MV) *
  				     VSINKDISCONNECT_PD_MIN_PERCENT / 100;
  	} else {
  		/* 3.5V for non-pd sink */
  		threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;
  	}
  
  	threshold = threshold / TCPC_VBUS_SINK_DISCONNECT_THRESH_LSB_MV;
  
  	if (threshold > TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX)
  		return -EINVAL;
  
  write_thresh:
  	return tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, threshold);
  }
  
  static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(dev);
  	int ret;
  
  	/* To prevent disconnect during FRS, set disconnect threshold to 3.5V */
  	ret = tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, enable ? 0 : 0x8c);
  	if (ret < 0)
  		return ret;
  
  	ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_FAST_ROLE_SWAP_EN, enable ?
  				 TCPC_FAST_ROLE_SWAP_EN : 0);
  
  	return ret;
  }
  
  static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(dev);
  
  	if (tcpci->data->frs_sourcing_vbus)
  		tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
  }
  
  static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  
  	return regmap_update_bits(tcpci->regmap, TCPC_TCPC_CTRL, TCPC_TCPC_CTRL_BIST_TM,
  				 enable ? TCPC_TCPC_CTRL_BIST_TM : 0);
  }
  
  static int tcpci_set_roles(struct tcpc_dev *tcpc, bool attached,
  			   enum typec_role role, enum typec_data_role data)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg;
  	int ret;
  
  	reg = PD_REV20 << TCPC_MSG_HDR_INFO_REV_SHIFT;
  	if (role == TYPEC_SOURCE)
  		reg |= TCPC_MSG_HDR_INFO_PWR_ROLE;
  	if (data == TYPEC_HOST)
  		reg |= TCPC_MSG_HDR_INFO_DATA_ROLE;
  	ret = regmap_write(tcpci->regmap, TCPC_MSG_HDR_INFO, reg);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  static int tcpci_set_pd_rx(struct tcpc_dev *tcpc, bool enable)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg = 0;
  	int ret;
  
  	if (enable)
  		reg = TCPC_RX_DETECT_SOP | TCPC_RX_DETECT_HARD_RESET;
  	ret = regmap_write(tcpci->regmap, TCPC_RX_DETECT, reg);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  static int tcpci_get_vbus(struct tcpc_dev *tcpc)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg;
  	int ret;
  
  	ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg);
  	if (ret < 0)
  		return ret;
  
  	return !!(reg & TCPC_POWER_STATUS_VBUS_PRES);
  }
  
  static bool tcpci_is_vbus_vsafe0v(struct tcpc_dev *tcpc)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned int reg;
  	int ret;
  
  	ret = regmap_read(tcpci->regmap, TCPC_EXTENDED_STATUS, &reg);
  	if (ret < 0)
  		return false;
  
  	return !!(reg & TCPC_EXTENDED_STATUS_VSAFE0V);
  }
  
  static int tcpci_set_vbus(struct tcpc_dev *tcpc, bool source, bool sink)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	int ret;
  
  	if (tcpci->data->set_vbus) {
  		ret = tcpci->data->set_vbus(tcpci, tcpci->data, source, sink);
  		/* Bypass when ret > 0 */
  		if (ret != 0)
  			return ret < 0 ? ret : 0;
  	}
  
  	/* Disable both source and sink first before enabling anything */
  
  	if (!source) {
  		ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
  				   TCPC_CMD_DISABLE_SRC_VBUS);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (!sink) {
  		ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
  				   TCPC_CMD_DISABLE_SINK_VBUS);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (source) {
  		ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
  				   TCPC_CMD_SRC_VBUS_DEFAULT);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (sink) {
  		ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
  				   TCPC_CMD_SINK_VBUS);
  		if (ret < 0)
  			return ret;
  	}
  
  	return 0;
  }
  
  static int tcpci_pd_transmit(struct tcpc_dev *tcpc, enum tcpm_transmit_type type,
  			     const struct pd_message *msg, unsigned int negotiated_rev)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	u16 header = msg ? le16_to_cpu(msg->header) : 0;
  	unsigned int reg, cnt;
  	int ret;
  
  	cnt = msg ? pd_header_cnt(header) * 4 : 0;
  	/**
  	 * TCPCI spec forbids direct access of TCPC_TX_DATA.
  	 * But, since some of the chipsets offer this capability,
  	 * it's fair to support both.
  	 */
  	if (tcpci->data->TX_BUF_BYTE_x_hidden) {
  		u8 buf[TCPC_TRANSMIT_BUFFER_MAX_LEN] = {0,};
  		u8 pos = 0;
  
  		/* Payload + header + TCPC_TX_BYTE_CNT */
  		buf[pos++] = cnt + 2;
  
  		if (msg)
  			memcpy(&buf[pos], &msg->header, sizeof(msg->header));
  
  		pos += sizeof(header);
  
  		if (cnt > 0)
  			memcpy(&buf[pos], msg->payload, cnt);
  
  		pos += cnt;
  		ret = regmap_raw_write(tcpci->regmap, TCPC_TX_BYTE_CNT, buf, pos);
  		if (ret < 0)
  			return ret;
  	} else {
  		ret = regmap_write(tcpci->regmap, TCPC_TX_BYTE_CNT, cnt + 2);
  		if (ret < 0)
  			return ret;
  
  		ret = tcpci_write16(tcpci, TCPC_TX_HDR, header);
  		if (ret < 0)
  			return ret;
  
  		if (cnt > 0) {
  			ret = regmap_raw_write(tcpci->regmap, TCPC_TX_DATA, &msg->payload, cnt);
  			if (ret < 0)
  				return ret;
  		}
  	}
  
  	/* nRetryCount is 3 in PD2.0 spec where 2 in PD3.0 spec */
  	reg = ((negotiated_rev > PD_REV20 ? PD_RETRY_COUNT_3_0_OR_HIGHER : PD_RETRY_COUNT_DEFAULT)
  	       << TCPC_TRANSMIT_RETRY_SHIFT) | (type << TCPC_TRANSMIT_TYPE_SHIFT);
  	ret = regmap_write(tcpci->regmap, TCPC_TRANSMIT, reg);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  static int tcpci_init(struct tcpc_dev *tcpc)
  {
  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
  	unsigned long timeout = jiffies + msecs_to_jiffies(2000); /* XXX */
  	unsigned int reg;
  	int ret;
  
  	while (time_before_eq(jiffies, timeout)) {
  		ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg);
  		if (ret < 0)
  			return ret;
  		if (!(reg & TCPC_POWER_STATUS_UNINIT))
  			break;
  		usleep_range(10000, 20000);
  	}
  	if (time_after(jiffies, timeout))
  		return -ETIMEDOUT;
  
  	/* Handle vendor init */
  	if (tcpci->data->init) {
  		ret = tcpci->data->init(tcpci, tcpci->data);
  		if (ret < 0)
  			return ret;
  	}
  
  	/* Clear all events */
  	ret = tcpci_write16(tcpci, TCPC_ALERT, 0xffff);
  	if (ret < 0)
  		return ret;
  
  	if (tcpci->controls_vbus)
  		reg = TCPC_POWER_STATUS_VBUS_PRES;
  	else
  		reg = 0;
  	ret = regmap_write(tcpci->regmap, TCPC_POWER_STATUS_MASK, reg);
  	if (ret < 0)
  		return ret;
  
  	/* Enable Vbus detection */
  	ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
  			   TCPC_CMD_ENABLE_VBUS_DETECT);
  	if (ret < 0)
  		return ret;
  
  	reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
  		TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
  		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
  	if (tcpci->controls_vbus)
  		reg |= TCPC_ALERT_POWER_STATUS;
  	/* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
  	if (tcpci->data->vbus_vsafe0v) {
  		reg |= TCPC_ALERT_EXTENDED_STATUS;
  		ret = regmap_write(tcpci->regmap, TCPC_EXTENDED_STATUS_MASK,
  				   TCPC_EXTENDED_STATUS_VSAFE0V);
  		if (ret < 0)
  			return ret;
  	}
  	return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg);
  }
  
  irqreturn_t tcpci_irq(struct tcpci *tcpci)
  {
  	u16 status;
  	int ret;
  	unsigned int raw;
  
  	tcpci_read16(tcpci, TCPC_ALERT, &status);
  
  	/*
  	 * Clear alert status for everything except RX_STATUS, which shouldn't
  	 * be cleared until we have successfully retrieved message.
  	 */
  	if (status & ~TCPC_ALERT_RX_STATUS)
  		tcpci_write16(tcpci, TCPC_ALERT,
  			      status & ~TCPC_ALERT_RX_STATUS);
  
  	if (status & TCPC_ALERT_CC_STATUS)
  		tcpm_cc_change(tcpci->port);
  
  	if (status & TCPC_ALERT_POWER_STATUS) {
  		regmap_read(tcpci->regmap, TCPC_POWER_STATUS_MASK, &raw);
  		/*
  		 * If power status mask has been reset, then the TCPC
  		 * has reset.
  		 */
  		if (raw == 0xff)
  			tcpm_tcpc_reset(tcpci->port);
  		else
  			tcpm_vbus_change(tcpci->port);
  	}
  
  	if (status & TCPC_ALERT_RX_STATUS) {
  		struct pd_message msg;
  		unsigned int cnt, payload_cnt;
  		u16 header;
  
  		regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt);
  		/*
  		 * 'cnt' corresponds to READABLE_BYTE_COUNT in section 4.4.14
  		 * of the TCPCI spec [Rev 2.0 Ver 1.0 October 2017] and is
  		 * defined in table 4-36 as one greater than the number of
  		 * bytes received. And that number includes the header. So:
  		 */
  		if (cnt > 3)
  			payload_cnt = cnt - (1 + sizeof(msg.header));
  		else
  			payload_cnt = 0;
  
  		tcpci_read16(tcpci, TCPC_RX_HDR, &header);
  		msg.header = cpu_to_le16(header);
  
  		if (WARN_ON(payload_cnt > sizeof(msg.payload)))
  			payload_cnt = sizeof(msg.payload);
  
  		if (payload_cnt > 0)
  			regmap_raw_read(tcpci->regmap, TCPC_RX_DATA,
  					&msg.payload, payload_cnt);
  
  		/* Read complete, clear RX status alert bit */
  		tcpci_write16(tcpci, TCPC_ALERT, TCPC_ALERT_RX_STATUS);
  
  		tcpm_pd_receive(tcpci->port, &msg);
  	}
  
  	if (tcpci->data->vbus_vsafe0v && (status & TCPC_ALERT_EXTENDED_STATUS)) {
  		ret = regmap_read(tcpci->regmap, TCPC_EXTENDED_STATUS, &raw);
  		if (!ret && (raw & TCPC_EXTENDED_STATUS_VSAFE0V))
  			tcpm_vbus_change(tcpci->port);
  	}
  
  	if (status & TCPC_ALERT_RX_HARD_RST)
  		tcpm_pd_hard_reset(tcpci->port);
  
  	if (status & TCPC_ALERT_TX_SUCCESS)
  		tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_SUCCESS);
  	else if (status & TCPC_ALERT_TX_DISCARDED)
  		tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_DISCARDED);
  	else if (status & TCPC_ALERT_TX_FAILED)
  		tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_FAILED);
  
  	return IRQ_HANDLED;
  }
  EXPORT_SYMBOL_GPL(tcpci_irq);
  
  static irqreturn_t _tcpci_irq(int irq, void *dev_id)
  {
  	struct tcpci_chip *chip = dev_id;
  
  	return tcpci_irq(chip->tcpci);
  }
  
  static const struct regmap_config tcpci_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  
  	.max_register = 0x7F, /* 0x80 .. 0xFF are vendor defined */
  };
  
  static int tcpci_parse_config(struct tcpci *tcpci)
  {
  	tcpci->controls_vbus = true; /* XXX */
  
  	tcpci->tcpc.fwnode = device_get_named_child_node(tcpci->dev,
  							 "connector");
  	if (!tcpci->tcpc.fwnode) {
  		dev_err(tcpci->dev, "Can't find connector node.\n");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
  {
  	struct tcpci *tcpci;
  	int err;
  
  	tcpci = devm_kzalloc(dev, sizeof(*tcpci), GFP_KERNEL);
  	if (!tcpci)
  		return ERR_PTR(-ENOMEM);
  
  	tcpci->dev = dev;
  	tcpci->data = data;
  	tcpci->regmap = data->regmap;
  
  	tcpci->tcpc.init = tcpci_init;
  	tcpci->tcpc.get_vbus = tcpci_get_vbus;
  	tcpci->tcpc.set_vbus = tcpci_set_vbus;
  	tcpci->tcpc.set_cc = tcpci_set_cc;
  	tcpci->tcpc.apply_rc = tcpci_apply_rc;
  	tcpci->tcpc.get_cc = tcpci_get_cc;
  	tcpci->tcpc.set_polarity = tcpci_set_polarity;
  	tcpci->tcpc.set_vconn = tcpci_set_vconn;
  	tcpci->tcpc.start_toggling = tcpci_start_toggling;
  
  	tcpci->tcpc.set_pd_rx = tcpci_set_pd_rx;
  	tcpci->tcpc.set_roles = tcpci_set_roles;
  	tcpci->tcpc.pd_transmit = tcpci_pd_transmit;
  	tcpci->tcpc.set_bist_data = tcpci_set_bist_data;
  	tcpci->tcpc.enable_frs = tcpci_enable_frs;
  	tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
  	tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;
  
  	if (tcpci->data->auto_discharge_disconnect) {
  		tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
  		tcpci->tcpc.set_auto_vbus_discharge_threshold =
  			tcpci_set_auto_vbus_discharge_threshold;
  		regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_POWER_CTRL_BLEED_DISCHARGE,
  				   TCPC_POWER_CTRL_BLEED_DISCHARGE);
  	}
  
  	if (tcpci->data->vbus_vsafe0v)
  		tcpci->tcpc.is_vbus_vsafe0v = tcpci_is_vbus_vsafe0v;
  
  	err = tcpci_parse_config(tcpci);
  	if (err < 0)
  		return ERR_PTR(err);
  
  	tcpci->port = tcpm_register_port(tcpci->dev, &tcpci->tcpc);
  	if (IS_ERR(tcpci->port))
  		return ERR_CAST(tcpci->port);
  
  	return tcpci;
  }
  EXPORT_SYMBOL_GPL(tcpci_register_port);
  
  void tcpci_unregister_port(struct tcpci *tcpci)
  {
  	tcpm_unregister_port(tcpci->port);
  }
  EXPORT_SYMBOL_GPL(tcpci_unregister_port);
  
  static int tcpci_probe(struct i2c_client *client,
  		       const struct i2c_device_id *i2c_id)
  {
  	struct tcpci_chip *chip;
  	int err;
  	u16 val = 0;
  
  	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
  	if (!chip)
  		return -ENOMEM;
  
  	chip->data.regmap = devm_regmap_init_i2c(client, &tcpci_regmap_config);
  	if (IS_ERR(chip->data.regmap))
  		return PTR_ERR(chip->data.regmap);
  
  	i2c_set_clientdata(client, chip);
  
  	/* Disable chip interrupts before requesting irq */
  	err = regmap_raw_write(chip->data.regmap, TCPC_ALERT_MASK, &val,
  			       sizeof(u16));
  	if (err < 0)
  		return err;
  
  	chip->tcpci = tcpci_register_port(&client->dev, &chip->data);
  	if (IS_ERR(chip->tcpci))
  		return PTR_ERR(chip->tcpci);
  
  	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
  					_tcpci_irq,
  					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
  					dev_name(&client->dev), chip);
  	if (err < 0) {
  		tcpci_unregister_port(chip->tcpci);
  		return err;
  	}
  
  	return 0;
  }
  
  static int tcpci_remove(struct i2c_client *client)
  {
  	struct tcpci_chip *chip = i2c_get_clientdata(client);
  	int err;
  
  	/* Disable chip interrupts before unregistering port */
  	err = tcpci_write16(chip->tcpci, TCPC_ALERT_MASK, 0);
  	if (err < 0)
  		return err;
  
  	tcpci_unregister_port(chip->tcpci);
  
  	return 0;
  }
  
  static const struct i2c_device_id tcpci_id[] = {
  	{ "tcpci", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, tcpci_id);
  
  #ifdef CONFIG_OF
  static const struct of_device_id tcpci_of_match[] = {
  	{ .compatible = "nxp,ptn5110", },
  	{},
  };
  MODULE_DEVICE_TABLE(of, tcpci_of_match);
  #endif
  
  static struct i2c_driver tcpci_i2c_driver = {
  	.driver = {
  		.name = "tcpci",
  		.of_match_table = of_match_ptr(tcpci_of_match),
  	},
  	.probe = tcpci_probe,
  	.remove = tcpci_remove,
  	.id_table = tcpci_id,
  };
  module_i2c_driver(tcpci_i2c_driver);
  
  MODULE_DESCRIPTION("USB Type-C Port Controller Interface driver");
  MODULE_LICENSE("GPL");
  