path: root/driver/tcpm/nct38xx.c

/*
 * Copyright 2019 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/* Type-C port manager for Nuvoton NCT38XX. */

#include "common.h"
#include "console.h"
#include "hooks.h"
#include "nct38xx.h"
#include "task.h"
#include "tcpm/tcpci.h"
#include "usb_common.h"

#if !defined(CONFIG_USB_PD_TCPM_TCPCI)
#error "NCT38XX is using part of standard TCPCI control"
#error "Please upgrade your board configuration"
#endif

#define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)
#define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)

static enum nct38xx_boot_type boot_type[CONFIG_USB_PD_PORT_MAX_COUNT];

enum nct38xx_boot_type nct38xx_get_boot_type(int port)
{
	return boot_type[port];
}

void nct38xx_reset_notify(int port)
{
	/* A full reset also resets the chip's dead battery boot status */
	boot_type[port] = NCT38XX_BOOT_UNKNOWN;
}

static int nct38xx_init(int port)
{
	int rv;
	int reg;

	/*
	 * Detect dead battery boot by the default role control value of 0x0A
	 * once per EC run
	 */
	if (boot_type[port] == NCT38XX_BOOT_UNKNOWN) {
		RETURN_ERROR(tcpc_read(port, TCPC_REG_ROLE_CTRL, &reg));

		if (reg == NCT38XX_ROLE_CTRL_DEAD_BATTERY)
			boot_type[port] = NCT38XX_BOOT_DEAD_BATTERY;
		else
			boot_type[port] = NCT38XX_BOOT_NORMAL;
	}

	RETURN_ERROR(tcpc_read(port, TCPC_REG_POWER_STATUS, &reg));

	/*
	 * Set TCPC_CONTROL.DebugAccessoryControl = 1 to control by TCPM,
	 * not TCPC in most cases.  This must be left alone if we're on a
	 * dead battery boot with a debug accessory.  CC line detection will
	 * be delayed if we have booted from a dead battery with a debug
	 * accessory and change this bit (see b/186799392).
	 */
	if ((boot_type[port] == NCT38XX_BOOT_DEAD_BATTERY) &&
				(reg & TCPC_REG_POWER_STATUS_DEBUG_ACC_CON))
		CPRINTS("C%d: Booted in dead battery mode, not changing debug"
			" control", port);
	else if (tcpc_config[port].flags & TCPC_FLAGS_NO_DEBUG_ACC_CONTROL)
		CPRINTS("C%d: NO_DEBUG_ACC_CONTROL", port);
	else
		RETURN_ERROR(tcpc_update8(port, TCPC_REG_TCPC_CTRL,
					  TCPC_REG_TCPC_CTRL_DEBUG_ACC_CONTROL,
					  MASK_SET));

	/*
	 * Write to the CONTROL_OUT_EN register to enable:
	 * [6] - CONNDIREN : Connector direction indication output enable
	 * [2] - SNKEN     : VBUS sink enable output enable
	 * [0] - SRCEN     : VBUS source voltage enable output enable
	 */
	reg = NCT38XX_REG_CTRL_OUT_EN_SRCEN |
	      NCT38XX_REG_CTRL_OUT_EN_SNKEN |
	      NCT38XX_REG_CTRL_OUT_EN_CONNDIREN;

	rv = tcpc_write(port, NCT38XX_REG_CTRL_OUT_EN, reg);
	if (rv)
		return rv;

	/* Disable OVP */
	rv = tcpc_update8(port,
			  TCPC_REG_FAULT_CTRL,
			  TCPC_REG_FAULT_CTRL_VBUS_OVP_FAULT_DIS,
			  MASK_SET);
	if (rv)
		return rv;

	/* Enable VBus monitor and Disable FRS */
	rv = tcpc_update8(port,
			  TCPC_REG_POWER_CTRL,
			  (TCPC_REG_POWER_CTRL_VBUS_VOL_MONITOR_DIS |
			   TCPC_REG_POWER_CTRL_FRS_ENABLE),
			  MASK_CLR);
	if (rv)
		return rv;

	/* Set FRS direction for SNK detect, if FRS is enabled */
	if (IS_ENABLED(CONFIG_USB_PD_FRS_TCPC)) {
		reg = TCPC_REG_DEV_CAP_2_SNK_FR_SWAP;
		rv = tcpc_write(port, TCPC_REG_DEV_CAP_2, reg);
		if (rv)
			return rv;

		reg = TCPC_REG_CONFIG_EXT_1_FR_SWAP_SNK_DIR;
		rv = tcpc_write(port, TCPC_REG_CONFIG_EXT_1, reg);
		if (rv)
			return rv;
	}

	/* Start VBus monitor */
	rv = tcpc_write(port, TCPC_REG_COMMAND,
			TCPC_REG_COMMAND_ENABLE_VBUS_DETECT);
	if (rv)
		return rv;

	/**
	 * Set driver specific ALERT mask bits
	 *
	 * Wake up on faults
	 */
	reg = TCPC_REG_ALERT_FAULT;

	/*
	 * Enable the Vendor Define alert event only when the IO expander
	 * feature is defined
	 */
	if (IS_ENABLED(CONFIG_IO_EXPANDER_NCT38XX))
		reg |= TCPC_REG_ALERT_VENDOR_DEF;

	rv = tcpc_update16(port,
			   TCPC_REG_ALERT_MASK,
			   reg,
			   MASK_SET);

	if (rv)
		return rv;

	/* Enable full VCONN protection (Over-Current and Short-Circuit) */
	reg = NCT38XX_REG_VBC_FAULT_CTL_VC_OCP_EN |
	      NCT38XX_REG_VBC_FAULT_CTL_VC_SCP_EN |
	      NCT38XX_REG_VBC_FAULT_CTL_FAULT_VC_OFF;

	rv = tcpc_update8(port,
			  NCT38XX_REG_VBC_FAULT_CTL,
			  reg,
			  MASK_SET);

	return rv;
}

static int nct38xx_tcpm_init(int port)
{
	int rv;

	rv = tcpci_tcpm_init(port);
	if (rv)
		return rv;

	return nct38xx_init(port);
}

static int nct38xx_tcpm_set_cc(int port, int pull)
{
	/*
	 * Setting the CC lines to open/open requires that the NCT CTRL_OUT
	 * register has sink disabled. Otherwise, when no battery is connected:
	 *
	 * 1. You set CC lines to Open/Open. This is physically happening on
	 *    the CC line.
	 * 2. Since CC is now Open/Open, the internal TCPC HW state machine
	 *    is no longer in Attached.Snk and therefore our TCPC HW
	 *    automatically opens the sink switch (de-assert the VBSNK_EN pin)
	 * 3. Since sink switch is open, the TCPC VCC voltage starts to drop.
	 * 4. When TCPC VCC gets below ~2.7V the TCPC will reset and therefore
	 *    it will present Rd/Rd on the CC lines. Also the VBSNK_EN pin
	 *    after reset is Hi-Z, so the sink switch will get closed again.
	 *
	 * Disabling SNKEN makes the VBSNK_EN pin Hi-Z, so
	 * USB_Cx_TCPC_VBSNK_EN_L will be asserted by external
	 * pull-down, so only do so if already sinking, otherwise
	 * both source and sink switches can be closed, which should
	 * never happen (b/166850036).
	 *
	 * SNKEN will be re-enabled in nct38xx_init above (from tcpm_init), or
	 * when CC lines are set again, or when sinking is disabled.
	 */
	int rv;
	enum mask_update_action action =
			pull == TYPEC_CC_OPEN && tcpm_get_snk_ctrl(port) ?
				MASK_CLR : MASK_SET;

	rv = tcpc_update8(port,
			  NCT38XX_REG_CTRL_OUT_EN,
			  NCT38XX_REG_CTRL_OUT_EN_SNKEN,
			  action);
	if (rv)
		return rv;

	return tcpci_tcpm_set_cc(port, pull);
}

#ifdef CONFIG_USB_PD_PPC
static int nct38xx_tcpm_set_snk_ctrl(int port, int enable)
{
	int rv;

	/*
	 * To disable sinking, SNKEN must be enabled so that
	 * USB_Cx_TCPC_VBSNK_EN_L will be driven high.
	 */
	if (!enable) {
		rv = tcpc_update8(port,
				  NCT38XX_REG_CTRL_OUT_EN,
				  NCT38XX_REG_CTRL_OUT_EN_SNKEN,
				  MASK_SET);
		if (rv)
			return rv;
	}

	return tcpci_tcpm_set_snk_ctrl(port, enable);
}
#endif

static inline int tcpc_read_alert_no_lpm_exit(int port, int *val)
{
	return tcpc_addr_read16_no_lpm_exit(port,
					tcpc_config[port].i2c_info.addr_flags,
					TCPC_REG_ALERT, val);
}

/* Map Type-C port to IOEX port */
__overridable int board_map_nct38xx_tcpc_port_to_ioex(int port)
{
	return port;
}

static void nct38xx_tcpc_alert(int port)
{
	int alert, rv;

	/*
	 * The nct3808 is a dual port chip with a shared ALERT
	 * pin. Avoid taking a port out of LPM if it is not alerting.
	 *
	 * The nct38xx exits Idle mode when ALERT is signaled, so there
	 * is no need to run the TCPM LPM exit code to check the ALERT
	 * register bits (Ref. NCT38n7/8 Datasheet S 2.3.4 "Setting the
	 * I2C to * Idle"). In fact, running the TCPM LPM exit code
	 * causes a new CC Status ALERT which has the effect of creating
	 * a new ALERT as a side-effect of handing an ALERT.
	 */
	rv = tcpc_read_alert_no_lpm_exit(port, &alert);
	if (rv == EC_SUCCESS && alert == TCPC_REG_ALERT_NONE) {
		/* No ALERT on this port, return early. */
		return;
	}

	/* Process normal TCPC ALERT event and clear status. */
	tcpci_tcpc_alert(port);

	/*
	 * If the IO expander feature is enabled, use the ALERT register
	 * value read before it was cleared by calling
	 * tcpci_tcpc_alert().  Check the Vendor Defined Alert bit to
	 * handle the IOEX IO's interrupt event.
	 */
	if (IS_ENABLED(CONFIG_IO_EXPANDER_NCT38XX) &&
		rv == EC_SUCCESS && (alert & TCPC_REG_ALERT_VENDOR_DEF)) {
		int ioexport;

		ioexport = board_map_nct38xx_tcpc_port_to_ioex(port);
		nct38xx_ioex_event_handler(ioexport);
	}
}

static int nct3807_handle_fault(int port, int fault)
{
	int rv = EC_SUCCESS;

	/* Registers are set to default, initialize for our use */
	if (fault & TCPC_REG_FAULT_STATUS_ALL_REGS_RESET) {
		rv = nct38xx_init(port);
	} else {
		/* We don't use TCPC OVP, so just disable it */
		if (fault & TCPC_REG_FAULT_STATUS_VBUS_OVER_VOLTAGE) {
			/* Disable OVP */
			rv = tcpc_update8(port,
				  TCPC_REG_FAULT_CTRL,
				  TCPC_REG_FAULT_CTRL_VBUS_OVP_FAULT_DIS,
				  MASK_SET);
			if (rv)
				return rv;
		}
		/* Failing AutoDischargeDisconnect should disable it */
		if (fault & TCPC_REG_FAULT_STATUS_AUTO_DISCHARGE_FAIL)
			tcpm_enable_auto_discharge_disconnect(port, 0);
	}
	return rv;
}

__maybe_unused static int nct38xx_set_frs_enable(int port, int enable)
{
	/*
	 * From b/192012189: Enabling FRS for this chip should:
	 *
	 * 1.  Make sure that the sink will not disconnect if Vbus will drop
	 * due to the Fast Role Swap by setting VBUS_SINK_DISCONNECT_THRESHOLD
	 * to 0
	 * 2. Enable the FRS interrupt (already done in TCPCI alert init)
	 * 3. Set POWER_CONTORL.FastRoleSwapEnable to 1
	 */
	RETURN_ERROR(tcpc_write16(port,
				TCPC_REG_VBUS_SINK_DISCONNECT_THRESH,
				enable ? 0x0000 :
				TCPC_REG_VBUS_SINK_DISCONNECT_THRESH_DEFAULT));

	return tcpc_update8(port,
			    TCPC_REG_POWER_CTRL,
			    TCPC_REG_POWER_CTRL_FRS_ENABLE,
			    enable ? MASK_SET : MASK_CLR);
}

const struct tcpm_drv nct38xx_tcpm_drv = {
	.init			= &nct38xx_tcpm_init,
	.release		= &tcpci_tcpm_release,
	.get_cc			= &tcpci_tcpm_get_cc,
#ifdef CONFIG_USB_PD_VBUS_DETECT_TCPC
	.check_vbus_level	= &tcpci_tcpm_check_vbus_level,
#endif
	.select_rp_value	= &tcpci_tcpm_select_rp_value,
	.set_cc			= &nct38xx_tcpm_set_cc,
	.set_polarity		= &tcpci_tcpm_set_polarity,
#ifdef CONFIG_USB_PD_DECODE_SOP
	.sop_prime_enable	= &tcpci_tcpm_sop_prime_enable,
#endif
	.set_vconn		= &tcpci_tcpm_set_vconn,
	.set_msg_header		= &tcpci_tcpm_set_msg_header,
	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
	.get_message_raw	= &tcpci_tcpm_get_message_raw,
	.transmit		= &tcpci_tcpm_transmit,
	.tcpc_alert		= &nct38xx_tcpc_alert,
#ifdef CONFIG_USB_PD_DISCHARGE_TCPC
	.tcpc_discharge_vbus	= &tcpci_tcpc_discharge_vbus,
#endif
	.tcpc_enable_auto_discharge_disconnect =
				  &tcpci_tcpc_enable_auto_discharge_disconnect,
	.debug_accessory	= &tcpci_tcpc_debug_accessory,

#ifdef CONFIG_USB_PD_DUAL_ROLE_AUTO_TOGGLE
	.drp_toggle		= &tcpci_tcpc_drp_toggle,
#endif
#ifdef CONFIG_USB_PD_PPC
	.get_snk_ctrl		= &tcpci_tcpm_get_snk_ctrl,
	.set_snk_ctrl		= &nct38xx_tcpm_set_snk_ctrl,
	.get_src_ctrl		= &tcpci_tcpm_get_src_ctrl,
	.set_src_ctrl		= &tcpci_tcpm_set_src_ctrl,
#endif
	.get_chip_info		= &tcpci_get_chip_info,
#ifdef CONFIG_USB_PD_TCPC_LOW_POWER
	.enter_low_power_mode	= &tcpci_enter_low_power_mode,
#endif
	.set_bist_test_mode	= &tcpci_set_bist_test_mode,
#ifdef CONFIG_USB_PD_FRS_TCPC
	.set_frs_enable         = &nct38xx_set_frs_enable,
#endif
	.handle_fault		= &nct3807_handle_fault,
};