// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019 Intel Corporation
 */

#include "i915_drv.h"
#include "intel_display.h"
#include "intel_display_types.h"
#include "intel_dp_mst.h"
#include "intel_tc.h"

static const char *tc_port_mode_name(enum tc_port_mode mode)
{
        static const char * const names[] = {
                [TC_PORT_TBT_ALT] = "tbt-alt",
                [TC_PORT_DP_ALT] = "dp-alt",
                [TC_PORT_LEGACY] = "legacy",
        };

        if (WARN_ON(mode >= ARRAY_SIZE(names)))
                mode = TC_PORT_TBT_ALT;

        return names[mode];
}

static void
tc_port_load_fia_params(struct drm_i915_private *i915,
                        struct intel_digital_port *dig_port)
{
        enum port port = dig_port->base.port;
        enum tc_port tc_port = intel_port_to_tc(i915, port);
        u32 modular_fia;

        if (INTEL_INFO(i915)->display.has_modular_fia) {
                modular_fia = intel_uncore_read(&i915->uncore,
                                                PORT_TX_DFLEXDPSP(FIA1));
                drm_WARN_ON(&i915->drm, modular_fia == 0xffffffff);
                modular_fia &= MODULAR_FIA_MASK;
        } else {
                modular_fia = 0;
        }

        /*
         * Each Modular FIA instance houses 2 TC ports. In SOC that has more
         * than two TC ports, there are multiple instances of Modular FIA.
         */
        if (modular_fia) {
                dig_port->tc_phy_fia = tc_port / 2;
                dig_port->tc_phy_fia_idx = tc_port % 2;
        } else {
                dig_port->tc_phy_fia = FIA1;
                dig_port->tc_phy_fia_idx = tc_port;
        }
}

static enum intel_display_power_domain
tc_cold_get_power_domain(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);

        if (INTEL_GEN(i915) == 11)
                return intel_legacy_aux_to_power_domain(dig_port->aux_ch);
        else
                return POWER_DOMAIN_TC_COLD_OFF;
}

static intel_wakeref_t
tc_cold_block(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        enum intel_display_power_domain domain;

        if (INTEL_GEN(i915) == 11 && !dig_port->tc_legacy_port)
                return 0;

        domain = tc_cold_get_power_domain(dig_port);
        return intel_display_power_get(i915, domain);
}

static void
tc_cold_unblock(struct intel_digital_port *dig_port, intel_wakeref_t wakeref)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        enum intel_display_power_domain domain;

        /*
         * wakeref == -1, means some error happened saving save_depot_stack but
         * power should still be put down and 0 is a invalid save_depot_stack
         * id so can be used to skip it for non TC legacy ports.
         */
        if (wakeref == 0)
                return;

        domain = tc_cold_get_power_domain(dig_port);
        intel_display_power_put_async(i915, domain, wakeref);
}

static void
assert_tc_cold_blocked(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        bool enabled;

        if (INTEL_GEN(i915) == 11 && !dig_port->tc_legacy_port)
                return;

        enabled = intel_display_power_is_enabled(i915,
                                                 tc_cold_get_power_domain(dig_port));
        drm_WARN_ON(&i915->drm, !enabled);
}

u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        u32 lane_mask;

        lane_mask = intel_uncore_read(uncore,
                                      PORT_TX_DFLEXDPSP(dig_port->tc_phy_fia));

        drm_WARN_ON(&i915->drm, lane_mask == 0xffffffff);
        assert_tc_cold_blocked(dig_port);

        lane_mask &= DP_LANE_ASSIGNMENT_MASK(dig_port->tc_phy_fia_idx);
        return lane_mask >> DP_LANE_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
}

u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        u32 pin_mask;

        pin_mask = intel_uncore_read(uncore,
                                     PORT_TX_DFLEXPA1(dig_port->tc_phy_fia));

        drm_WARN_ON(&i915->drm, pin_mask == 0xffffffff);
        assert_tc_cold_blocked(dig_port);

        return (pin_mask & DP_PIN_ASSIGNMENT_MASK(dig_port->tc_phy_fia_idx)) >>
               DP_PIN_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
}

int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        intel_wakeref_t wakeref;
        u32 lane_mask;

        if (dig_port->tc_mode != TC_PORT_DP_ALT)
                return 4;

        assert_tc_cold_blocked(dig_port);

        lane_mask = 0;
        with_intel_display_power(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref)
                lane_mask = intel_tc_port_get_lane_mask(dig_port);

        switch (lane_mask) {
        default:
                MISSING_CASE(lane_mask);
                fallthrough;
        case 0x1:
        case 0x2:
        case 0x4:
        case 0x8:
                return 1;
        case 0x3:
        case 0xc:
                return 2;
        case 0xf:
                return 4;
        }
}

void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,
                                      int required_lanes)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        bool lane_reversal = dig_port->saved_port_bits & DDI_BUF_PORT_REVERSAL;
        struct intel_uncore *uncore = &i915->uncore;
        u32 val;

        drm_WARN_ON(&i915->drm,
                    lane_reversal && dig_port->tc_mode != TC_PORT_LEGACY);

        assert_tc_cold_blocked(dig_port);

        val = intel_uncore_read(uncore,
                                PORT_TX_DFLEXDPMLE1(dig_port->tc_phy_fia));
        val &= ~DFLEXDPMLE1_DPMLETC_MASK(dig_port->tc_phy_fia_idx);

        switch (required_lanes) {
        case 1:
                val |= lane_reversal ?
                        DFLEXDPMLE1_DPMLETC_ML3(dig_port->tc_phy_fia_idx) :
                        DFLEXDPMLE1_DPMLETC_ML0(dig_port->tc_phy_fia_idx);
                break;
        case 2:
                val |= lane_reversal ?
                        DFLEXDPMLE1_DPMLETC_ML3_2(dig_port->tc_phy_fia_idx) :
                        DFLEXDPMLE1_DPMLETC_ML1_0(dig_port->tc_phy_fia_idx);
                break;
        case 4:
                val |= DFLEXDPMLE1_DPMLETC_ML3_0(dig_port->tc_phy_fia_idx);
                break;
        default:
                MISSING_CASE(required_lanes);
        }

        intel_uncore_write(uncore,
                           PORT_TX_DFLEXDPMLE1(dig_port->tc_phy_fia), val);
}

static void tc_port_fixup_legacy_flag(struct intel_digital_port *dig_port,
                                      u32 live_status_mask)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        u32 valid_hpd_mask;

        if (dig_port->tc_legacy_port)
                valid_hpd_mask = BIT(TC_PORT_LEGACY);
        else
                valid_hpd_mask = BIT(TC_PORT_DP_ALT) |
                                 BIT(TC_PORT_TBT_ALT);

        if (!(live_status_mask & ~valid_hpd_mask))
                return;

        /* If live status mismatches the VBT flag, trust the live status. */
        drm_err(&i915->drm,
                "Port %s: live status %08x mismatches the legacy port flag, fix flag\n",
                dig_port->tc_port_name, live_status_mask);

        dig_port->tc_legacy_port = !dig_port->tc_legacy_port;
}

static u32 tc_port_live_status_mask(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        u32 isr_bit = i915->hotplug.pch_hpd[dig_port->base.hpd_pin];
        u32 mask = 0;
        u32 val;

        val = intel_uncore_read(uncore,
                                PORT_TX_DFLEXDPSP(dig_port->tc_phy_fia));

        if (val == 0xffffffff) {
                drm_dbg_kms(&i915->drm,
                            "Port %s: PHY in TCCOLD, nothing connected\n",
                            dig_port->tc_port_name);
                return mask;
        }

        if (val & TC_LIVE_STATE_TBT(dig_port->tc_phy_fia_idx))
                mask |= BIT(TC_PORT_TBT_ALT);
        if (val & TC_LIVE_STATE_TC(dig_port->tc_phy_fia_idx))
                mask |= BIT(TC_PORT_DP_ALT);

        if (intel_uncore_read(uncore, SDEISR) & isr_bit)
                mask |= BIT(TC_PORT_LEGACY);

        /* The sink can be connected only in a single mode. */
        if (!drm_WARN_ON(&i915->drm, hweight32(mask) > 1))
                tc_port_fixup_legacy_flag(dig_port, mask);

        return mask;
}

static bool icl_tc_phy_status_complete(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        u32 val;

        val = intel_uncore_read(uncore,
                                PORT_TX_DFLEXDPPMS(dig_port->tc_phy_fia));
        if (val == 0xffffffff) {
                drm_dbg_kms(&i915->drm,
                            "Port %s: PHY in TCCOLD, assuming not complete\n",
                            dig_port->tc_port_name);
                return false;
        }

        return val & DP_PHY_MODE_STATUS_COMPLETED(dig_port->tc_phy_fia_idx);
}

static bool icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port,
                                     bool enable)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        u32 val;

        val = intel_uncore_read(uncore,
                                PORT_TX_DFLEXDPCSSS(dig_port->tc_phy_fia));
        if (val == 0xffffffff) {
                drm_dbg_kms(&i915->drm,
                            "Port %s: PHY in TCCOLD, can't set safe-mode to %s\n",
                            dig_port->tc_port_name, enableddisabled(enable));

                return false;
        }

        val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(dig_port->tc_phy_fia_idx);
        if (!enable)
                val |= DP_PHY_MODE_STATUS_NOT_SAFE(dig_port->tc_phy_fia_idx);

        intel_uncore_write(uncore,
                           PORT_TX_DFLEXDPCSSS(dig_port->tc_phy_fia), val);

        if (enable && wait_for(!icl_tc_phy_status_complete(dig_port), 10))
                drm_dbg_kms(&i915->drm,
                            "Port %s: PHY complete clear timed out\n",
                            dig_port->tc_port_name);

        return true;
}

static bool icl_tc_phy_is_in_safe_mode(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        u32 val;

        val = intel_uncore_read(uncore,
                                PORT_TX_DFLEXDPCSSS(dig_port->tc_phy_fia));
        if (val == 0xffffffff) {
                drm_dbg_kms(&i915->drm,
                            "Port %s: PHY in TCCOLD, assume safe mode\n",
                            dig_port->tc_port_name);
                return true;
        }

        return !(val & DP_PHY_MODE_STATUS_NOT_SAFE(dig_port->tc_phy_fia_idx));
}

/*
 * This function implements the first part of the Connect Flow described by our
 * specification, Gen11 TypeC Programming chapter. The rest of the flow (reading
 * lanes, EDID, etc) is done as needed in the typical places.
 *
 * Unlike the other ports, type-C ports are not available to use as soon as we
 * get a hotplug. The type-C PHYs can be shared between multiple controllers:
 * display, USB, etc. As a result, handshaking through FIA is required around
 * connect and disconnect to cleanly transfer ownership with the controller and
 * set the type-C power state.
 */
static void icl_tc_phy_connect(struct intel_digital_port *dig_port,
                               int required_lanes)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        int max_lanes;

        if (!icl_tc_phy_status_complete(dig_port)) {
                drm_dbg_kms(&i915->drm, "Port %s: PHY not ready\n",
                            dig_port->tc_port_name);
                goto out_set_tbt_alt_mode;
        }

        if (!icl_tc_phy_set_safe_mode(dig_port, false) &&
            !drm_WARN_ON(&i915->drm, dig_port->tc_legacy_port))
                goto out_set_tbt_alt_mode;

        max_lanes = intel_tc_port_fia_max_lane_count(dig_port);
        if (dig_port->tc_legacy_port) {
                drm_WARN_ON(&i915->drm, max_lanes != 4);
                dig_port->tc_mode = TC_PORT_LEGACY;

                return;
        }

        /*
         * Now we have to re-check the live state, in case the port recently
         * became disconnected. Not necessary for legacy mode.
         */
        if (!(tc_port_live_status_mask(dig_port) & BIT(TC_PORT_DP_ALT))) {
                drm_dbg_kms(&i915->drm, "Port %s: PHY sudden disconnect\n",
                            dig_port->tc_port_name);
                goto out_set_safe_mode;
        }

        if (max_lanes < required_lanes) {
                drm_dbg_kms(&i915->drm,
                            "Port %s: PHY max lanes %d < required lanes %d\n",
                            dig_port->tc_port_name,
                            max_lanes, required_lanes);
                goto out_set_safe_mode;
        }

        dig_port->tc_mode = TC_PORT_DP_ALT;

        return;

out_set_safe_mode:
        icl_tc_phy_set_safe_mode(dig_port, true);
out_set_tbt_alt_mode:
        dig_port->tc_mode = TC_PORT_TBT_ALT;
}

/*
 * See the comment at the connect function. This implements the Disconnect
 * Flow.
 */
static void icl_tc_phy_disconnect(struct intel_digital_port *dig_port)
{
        switch (dig_port->tc_mode) {
        case TC_PORT_LEGACY:
                /* Nothing to do, we never disconnect from legacy mode */
                break;
        case TC_PORT_DP_ALT:
                icl_tc_phy_set_safe_mode(dig_port, true);
                dig_port->tc_mode = TC_PORT_TBT_ALT;
                break;
        case TC_PORT_TBT_ALT:
                /* Nothing to do, we stay in TBT-alt mode */
                break;
        default:
                MISSING_CASE(dig_port->tc_mode);
        }
}

static bool icl_tc_phy_is_connected(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);

        if (!icl_tc_phy_status_complete(dig_port)) {
                drm_dbg_kms(&i915->drm, "Port %s: PHY status not complete\n",
                            dig_port->tc_port_name);
                return dig_port->tc_mode == TC_PORT_TBT_ALT;
        }

        if (icl_tc_phy_is_in_safe_mode(dig_port)) {
                drm_dbg_kms(&i915->drm, "Port %s: PHY still in safe mode\n",
                            dig_port->tc_port_name);

                return false;
        }

        return dig_port->tc_mode == TC_PORT_DP_ALT ||
               dig_port->tc_mode == TC_PORT_LEGACY;
}

static enum tc_port_mode
intel_tc_port_get_current_mode(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        u32 live_status_mask = tc_port_live_status_mask(dig_port);
        bool in_safe_mode = icl_tc_phy_is_in_safe_mode(dig_port);
        enum tc_port_mode mode;

        if (in_safe_mode ||
            drm_WARN_ON(&i915->drm, !icl_tc_phy_status_complete(dig_port)))
                return TC_PORT_TBT_ALT;

        mode = dig_port->tc_legacy_port ? TC_PORT_LEGACY : TC_PORT_DP_ALT;
        if (live_status_mask) {
                enum tc_port_mode live_mode = fls(live_status_mask) - 1;

                if (!drm_WARN_ON(&i915->drm, live_mode == TC_PORT_TBT_ALT))
                        mode = live_mode;
        }

        return mode;
}

static enum tc_port_mode
intel_tc_port_get_target_mode(struct intel_digital_port *dig_port)
{
        u32 live_status_mask = tc_port_live_status_mask(dig_port);

        if (live_status_mask)
                return fls(live_status_mask) - 1;

        return icl_tc_phy_status_complete(dig_port) &&
               dig_port->tc_legacy_port ? TC_PORT_LEGACY :
                                          TC_PORT_TBT_ALT;
}

static void intel_tc_port_reset_mode(struct intel_digital_port *dig_port,
                                     int required_lanes)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        enum tc_port_mode old_tc_mode = dig_port->tc_mode;

        intel_display_power_flush_work(i915);
        if (INTEL_GEN(i915) != 11 || !dig_port->tc_legacy_port) {
                enum intel_display_power_domain aux_domain;
                bool aux_powered;

                aux_domain = intel_aux_power_domain(dig_port);
                aux_powered = intel_display_power_is_enabled(i915, aux_domain);
                drm_WARN_ON(&i915->drm, aux_powered);
        }

        icl_tc_phy_disconnect(dig_port);
        icl_tc_phy_connect(dig_port, required_lanes);

        drm_dbg_kms(&i915->drm, "Port %s: TC port mode reset (%s -> %s)\n",
                    dig_port->tc_port_name,
                    tc_port_mode_name(old_tc_mode),
                    tc_port_mode_name(dig_port->tc_mode));
}

static void
intel_tc_port_link_init_refcount(struct intel_digital_port *dig_port,
                                 int refcount)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);

        drm_WARN_ON(&i915->drm, dig_port->tc_link_refcount);
        dig_port->tc_link_refcount = refcount;
}

void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        struct intel_encoder *encoder = &dig_port->base;
        intel_wakeref_t tc_cold_wref;
        int active_links = 0;

        mutex_lock(&dig_port->tc_lock);
        tc_cold_wref = tc_cold_block(dig_port);

        dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
        if (dig_port->dp.is_mst)
                active_links = intel_dp_mst_encoder_active_links(dig_port);
        else if (encoder->base.crtc)
                active_links = to_intel_crtc(encoder->base.crtc)->active;

        if (active_links) {
                if (!icl_tc_phy_is_connected(dig_port))
                        drm_dbg_kms(&i915->drm,
                                    "Port %s: PHY disconnected with %d active link(s)\n",
                                    dig_port->tc_port_name, active_links);
                intel_tc_port_link_init_refcount(dig_port, active_links);

                goto out;
        }

        if (dig_port->tc_legacy_port)
                icl_tc_phy_connect(dig_port, 1);

out:
        drm_dbg_kms(&i915->drm, "Port %s: sanitize mode (%s)\n",
                    dig_port->tc_port_name,
                    tc_port_mode_name(dig_port->tc_mode));

        tc_cold_unblock(dig_port, tc_cold_wref);
        mutex_unlock(&dig_port->tc_lock);
}

static bool intel_tc_port_needs_reset(struct intel_digital_port *dig_port)
{
        return intel_tc_port_get_target_mode(dig_port) != dig_port->tc_mode;
}

/*
 * The type-C ports are different because even when they are connected, they may
 * not be available/usable by the graphics driver: see the comment on
 * icl_tc_phy_connect(). So in our driver instead of adding the additional
 * concept of "usable" and make everything check for "connected and usable" we
 * define a port as "connected" when it is not only connected, but also when it
 * is usable by the rest of the driver. That maintains the old assumption that
 * connected ports are usable, and avoids exposing to the users objects they
 * can't really use.
 */
bool intel_tc_port_connected(struct intel_encoder *encoder)
{
        struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
        bool is_connected;
        intel_wakeref_t tc_cold_wref;

        intel_tc_port_lock(dig_port);
        tc_cold_wref = tc_cold_block(dig_port);

        is_connected = tc_port_live_status_mask(dig_port) &
                       BIT(dig_port->tc_mode);

        tc_cold_unblock(dig_port, tc_cold_wref);
        intel_tc_port_unlock(dig_port);

        return is_connected;
}

static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
                                 int required_lanes)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        intel_wakeref_t wakeref;

        wakeref = intel_display_power_get(i915, POWER_DOMAIN_DISPLAY_CORE);

        mutex_lock(&dig_port->tc_lock);

        if (!dig_port->tc_link_refcount) {
                intel_wakeref_t tc_cold_wref;

                tc_cold_wref = tc_cold_block(dig_port);

                if (intel_tc_port_needs_reset(dig_port))
                        intel_tc_port_reset_mode(dig_port, required_lanes);

                tc_cold_unblock(dig_port, tc_cold_wref);
        }

        drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
        dig_port->tc_lock_wakeref = wakeref;
}

void intel_tc_port_lock(struct intel_digital_port *dig_port)
{
        __intel_tc_port_lock(dig_port, 1);
}

void intel_tc_port_unlock(struct intel_digital_port *dig_port)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);

        mutex_unlock(&dig_port->tc_lock);

        intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
                                      wakeref);
}

bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
{
        return mutex_is_locked(&dig_port->tc_lock) ||
               dig_port->tc_link_refcount;
}

void intel_tc_port_get_link(struct intel_digital_port *dig_port,
                            int required_lanes)
{
        __intel_tc_port_lock(dig_port, required_lanes);
        dig_port->tc_link_refcount++;
        intel_tc_port_unlock(dig_port);
}

void intel_tc_port_put_link(struct intel_digital_port *dig_port)
{
        mutex_lock(&dig_port->tc_lock);
        dig_port->tc_link_refcount--;
        mutex_unlock(&dig_port->tc_lock);
}

void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
{
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
        enum port port = dig_port->base.port;
        enum tc_port tc_port = intel_port_to_tc(i915, port);

        if (drm_WARN_ON(&i915->drm, tc_port == PORT_TC_NONE))
                return;

        snprintf(dig_port->tc_port_name, sizeof(dig_port->tc_port_name),
                 "%c/TC#%d", port_name(port), tc_port + 1);

        mutex_init(&dig_port->tc_lock);
        dig_port->tc_legacy_port = is_legacy;
        dig_port->tc_link_refcount = 0;
        tc_port_load_fia_params(i915, dig_port);
}