/* 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.
 */

/*
 * Contains common USB functions shared between the old (i.e. usb_pd_protocol)
 * and the new (i.e. usb_sm_*) USB-C PD stacks.
 */

#include "common.h"
#include "charge_state.h"
#include "usb_pd.h"
#include "usb_pd_tcpm.h"
#include "util.h"

int usb_get_battery_soc(void)
{
#if defined(CONFIG_CHARGER)
	return charge_get_percent();
#elif defined(CONFIG_BATTERY)
	return board_get_battery_soc();
#else
	return 0;
#endif
}

/*
 * CC values for regular sources and Debug sources (aka DTS)
 *
 * Source type  Mode of Operation   CC1    CC2
 * ---------------------------------------------
 * Regular      Default USB Power   RpUSB  Open
 * Regular      USB-C @ 1.5 A       Rp1A5  Open
 * Regular      USB-C @ 3 A	    Rp3A0  Open
 * DTS		Default USB Power   Rp3A0  Rp1A5
 * DTS		USB-C @ 1.5 A       Rp1A5  RpUSB
 * DTS		USB-C @ 3 A	    Rp3A0  RpUSB
 */

typec_current_t usb_get_typec_current_limit(enum pd_cc_polarity_type polarity,
	enum tcpc_cc_voltage_status cc1, enum tcpc_cc_voltage_status cc2)
{
	typec_current_t charge = 0;
	enum tcpc_cc_voltage_status cc = polarity ? cc2 : cc1;
	enum tcpc_cc_voltage_status cc_alt = polarity ? cc1 : cc2;

	switch (cc) {
	case TYPEC_CC_VOLT_RP_3_0:
		if (!cc_is_rp(cc_alt) || cc_alt == TYPEC_CC_VOLT_RP_DEF)
			charge = 3000;
		else if (cc_alt == TYPEC_CC_VOLT_RP_1_5)
			charge = 500;
		break;
	case TYPEC_CC_VOLT_RP_1_5:
		charge = 1500;
		break;
	case TYPEC_CC_VOLT_RP_DEF:
		charge = 500;
		break;
	default:
		break;
	}

	if (IS_ENABLED(CONFIG_USBC_DISABLE_CHARGE_FROM_RP_DEF) && charge == 500)
		charge = 0;

	if (cc_is_rp(cc_alt))
		charge |= TYPEC_CURRENT_DTS_MASK;

	return charge;
}

enum pd_cc_polarity_type get_snk_polarity(enum tcpc_cc_voltage_status cc1,
	enum tcpc_cc_voltage_status cc2)
{
	/* The following assumes:
	 *
	 * TYPEC_CC_VOLT_RP_3_0 > TYPEC_CC_VOLT_RP_1_5
	 * TYPEC_CC_VOLT_RP_1_5 > TYPEC_CC_VOLT_RP_DEF
	 * TYPEC_CC_VOLT_RP_DEF > TYPEC_CC_VOLT_OPEN
	 */
	return cc2 > cc1;
}

/*
 * Zinger implements a board specific usb policy that does not define
 * PD_MAX_VOLTAGE_MV and PD_OPERATING_POWER_MW. And in turn, does not
 * use the following functions.
 */
#if defined(PD_MAX_VOLTAGE_MV) && defined(PD_OPERATING_POWER_MW)
int pd_find_pdo_index(uint32_t src_cap_cnt, const uint32_t * const src_caps,
					int max_mv, uint32_t *selected_pdo)
{
	int i, uw, mv;
	int ret = 0;
	int cur_uw = 0;
	int prefer_cur;

	int __attribute__((unused)) cur_mv = 0;

	/* max voltage is always limited by this boards max request */
	max_mv = MIN(max_mv, PD_MAX_VOLTAGE_MV);

	/* Get max power that is under our max voltage input */
	for (i = 0; i < src_cap_cnt; i++) {
		/* its an unsupported Augmented PDO (PD3.0) */
		if ((src_caps[i] & PDO_TYPE_MASK) == PDO_TYPE_AUGMENTED)
			continue;

		mv = ((src_caps[i] >> 10) & 0x3FF) * 50;
		/* Skip invalid voltage */
		if (!mv)
			continue;
		/* Skip any voltage not supported by this board */
		if (!pd_is_valid_input_voltage(mv))
			continue;

		if ((src_caps[i] & PDO_TYPE_MASK) == PDO_TYPE_BATTERY) {
			uw = 250000 * (src_caps[i] & 0x3FF);
		} else {
			int ma = (src_caps[i] & 0x3FF) * 10;

			ma = MIN(ma, PD_MAX_CURRENT_MA);
			uw = ma * mv;
		}

		if (mv > max_mv)
			continue;
		uw = MIN(uw, PD_MAX_POWER_MW * 1000);
		prefer_cur = 0;

		/* Apply special rules in case of 'tie' */
		if (IS_ENABLED(PD_PREFER_LOW_VOLTAGE)) {
			if (uw == cur_uw && mv < cur_mv)
				prefer_cur = 1;
		} else if (IS_ENABLED(PD_PREFER_HIGH_VOLTAGE)) {
			if (uw == cur_uw && mv > cur_mv)
				prefer_cur = 1;
		}

		/* Prefer higher power, except for tiebreaker */
		if (uw > cur_uw || prefer_cur) {
			ret = i;
			cur_uw = uw;
			cur_mv = mv;
		}
	}

	if (selected_pdo)
		*selected_pdo = src_caps[ret];

	return ret;
}

void pd_extract_pdo_power(uint32_t pdo, uint32_t *ma, uint32_t *mv)
{
	int max_ma, uw;

	*mv = ((pdo >> 10) & 0x3FF) * 50;

	if (*mv == 0) {
		*ma = 0;
		return;
	}

	if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_BATTERY) {
		uw = 250000 * (pdo & 0x3FF);
		max_ma = 1000 * MIN(1000 * uw, PD_MAX_POWER_MW) / *mv;
	} else {
		max_ma = 10 * (pdo & 0x3FF);
		max_ma = MIN(max_ma, PD_MAX_POWER_MW * 1000 / *mv);
	}

	*ma = MIN(max_ma, PD_MAX_CURRENT_MA);
}

void pd_build_request(uint32_t src_cap_cnt, const uint32_t * const src_caps,
			int32_t vpd_vdo, uint32_t *rdo, uint32_t *ma,
			uint32_t *mv, enum pd_request_type req_type,
			uint32_t max_request_mv)
{
	uint32_t pdo;
	int pdo_index, flags = 0;
	int uw;
	int max_or_min_ma;
	int max_or_min_mw;
	int max_vbus;
	int vpd_vbus_dcr;
	int vpd_gnd_dcr;

	if (req_type == PD_REQUEST_VSAFE5V) {
		/* src cap 0 should be vSafe5V */
		pdo_index = 0;
		pdo = src_caps[0];
	} else {
		/* find pdo index for max voltage we can request */
		pdo_index = pd_find_pdo_index(src_cap_cnt, src_caps,
						max_request_mv, &pdo);
	}

	pd_extract_pdo_power(pdo, ma, mv);

	/*
	 * Adjust VBUS current if CTVPD device was detected.
	 */
	if (vpd_vdo > 0) {
		max_vbus = VPD_VDO_MAX_VBUS(vpd_vdo);
		vpd_vbus_dcr = VPD_VDO_VBUS_IMP(vpd_vdo) << 1;
		vpd_gnd_dcr = VPD_VDO_GND_IMP(vpd_vdo);

		if (max_vbus > VPD_MAX_VBUS_50V)
			max_vbus = VPD_MAX_VBUS_20V;

		/*
		 * Valid max_vbus values:
		 *   20000 mV
		 *   30000 mV
		 *   40000 mV
		 *   50000 mV
		 */
		max_vbus = 20000 + max_vbus * 10000;
		if (*mv > max_vbus)
			*mv = max_vbus;

		/*
		 * 5000 mA cable: 150 = 750000 / 50000
		 * 3000 mA cable: 250 = 750000 / 30000
		 */
		if (*ma > 3000)
			*ma = 750000 / (150 + vpd_vbus_dcr + vpd_gnd_dcr);
		else
			*ma = 750000 / (250 + vpd_vbus_dcr + vpd_gnd_dcr);
	}

	uw = *ma * *mv;
	/* Mismatch bit set if less power offered than the operating power */
	if (uw < (1000 * PD_OPERATING_POWER_MW))
		flags |= RDO_CAP_MISMATCH;

#ifdef CONFIG_USB_PD_GIVE_BACK
		/* Tell source we are give back capable. */
		flags |= RDO_GIVE_BACK;

		/*
		 * BATTERY PDO: Inform the source that the sink will reduce
		 * power to this minimum level on receipt of a GotoMin Request.
		 */
		max_or_min_mw = PD_MIN_POWER_MW;

		/*
		 * FIXED or VARIABLE PDO: Inform the source that the sink will
		 * reduce current to this minimum level on receipt of a GotoMin
		 * Request.
		 */
		max_or_min_ma = PD_MIN_CURRENT_MA;
#else
		/*
		 * Can't give back, so set maximum current and power to
		 * operating level.
		 */
		max_or_min_ma = *ma;
		max_or_min_mw = uw / 1000;
#endif

	if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_BATTERY) {
		int mw = uw / 1000;
		*rdo = RDO_BATT(pdo_index + 1, mw, max_or_min_mw, flags);
	} else {
		*rdo = RDO_FIXED(pdo_index + 1, *ma, max_or_min_ma, flags);
	}
}
#endif