/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

/**
 * DOC: Panel Self Refresh (PSR/SRD)
 *
 * Since Haswell Display controller supports Panel Self-Refresh on display
 * panels witch have a remote frame buffer (RFB) implemented according to PSR
 * spec in eDP1.3. PSR feature allows the display to go to lower standby states
 * when system is idle but display is on as it eliminates display refresh
 * request to DDR memory completely as long as the frame buffer for that
 * display is unchanged.
 *
 * Panel Self Refresh must be supported by both Hardware (source) and
 * Panel (sink).
 *
 * PSR saves power by caching the framebuffer in the panel RFB, which allows us
 * to power down the link and memory controller. For DSI panels the same idea
 * is called "manual mode".
 *
 * The implementation uses the hardware-based PSR support which automatically
 * enters/exits self-refresh mode. The hardware takes care of sending the
 * required DP aux message and could even retrain the link (that part isn't
 * enabled yet though). The hardware also keeps track of any frontbuffer
 * changes to know when to exit self-refresh mode again. Unfortunately that
 * part doesn't work too well, hence why the i915 PSR support uses the
 * software frontbuffer tracking to make sure it doesn't miss a screen
 * update. For this integration intel_psr_invalidate() and intel_psr_flush()
 * get called by the frontbuffer tracking code. Note that because of locking
 * issues the self-refresh re-enable code is done from a work queue, which
 * must be correctly synchronized/cancelled when shutting down the pipe."
 */

#include <drm/drmP.h>

#include "intel_drv.h"
#include "i915_drv.h"

static bool psr_global_enabled(u32 debug)
{
        switch (debug & I915_PSR_DEBUG_MODE_MASK) {
        case I915_PSR_DEBUG_DEFAULT:
                return i915_modparams.enable_psr;
        case I915_PSR_DEBUG_DISABLE:
                return false;
        default:
                return true;
        }
}

static bool intel_psr2_enabled(struct drm_i915_private *dev_priv,
                               const struct intel_crtc_state *crtc_state)
{
        switch (dev_priv->psr.debug & I915_PSR_DEBUG_MODE_MASK) {
        case I915_PSR_DEBUG_FORCE_PSR1:
                return false;
        default:
                return crtc_state->has_psr2;
        }
}

void intel_psr_irq_control(struct drm_i915_private *dev_priv, u32 debug)
{
        u32 debug_mask, mask;

        mask = EDP_PSR_ERROR(TRANSCODER_EDP);
        debug_mask = EDP_PSR_POST_EXIT(TRANSCODER_EDP) |
                     EDP_PSR_PRE_ENTRY(TRANSCODER_EDP);

        if (INTEL_GEN(dev_priv) >= 8) {
                mask |= EDP_PSR_ERROR(TRANSCODER_A) |
                        EDP_PSR_ERROR(TRANSCODER_B) |
                        EDP_PSR_ERROR(TRANSCODER_C);

                debug_mask |= EDP_PSR_POST_EXIT(TRANSCODER_A) |
                              EDP_PSR_PRE_ENTRY(TRANSCODER_A) |
                              EDP_PSR_POST_EXIT(TRANSCODER_B) |
                              EDP_PSR_PRE_ENTRY(TRANSCODER_B) |
                              EDP_PSR_POST_EXIT(TRANSCODER_C) |
                              EDP_PSR_PRE_ENTRY(TRANSCODER_C);
        }

        if (debug & I915_PSR_DEBUG_IRQ)
                mask |= debug_mask;

        I915_WRITE(EDP_PSR_IMR, ~mask);
}

static void psr_event_print(u32 val, bool psr2_enabled)
{
        DRM_DEBUG_KMS("PSR exit events: 0x%x\n", val);
        if (val & PSR_EVENT_PSR2_WD_TIMER_EXPIRE)
                DRM_DEBUG_KMS("\tPSR2 watchdog timer expired\n");
        if ((val & PSR_EVENT_PSR2_DISABLED) && psr2_enabled)
                DRM_DEBUG_KMS("\tPSR2 disabled\n");
        if (val & PSR_EVENT_SU_DIRTY_FIFO_UNDERRUN)
                DRM_DEBUG_KMS("\tSU dirty FIFO underrun\n");
        if (val & PSR_EVENT_SU_CRC_FIFO_UNDERRUN)
                DRM_DEBUG_KMS("\tSU CRC FIFO underrun\n");
        if (val & PSR_EVENT_GRAPHICS_RESET)
                DRM_DEBUG_KMS("\tGraphics reset\n");
        if (val & PSR_EVENT_PCH_INTERRUPT)
                DRM_DEBUG_KMS("\tPCH interrupt\n");
        if (val & PSR_EVENT_MEMORY_UP)
                DRM_DEBUG_KMS("\tMemory up\n");
        if (val & PSR_EVENT_FRONT_BUFFER_MODIFY)
                DRM_DEBUG_KMS("\tFront buffer modification\n");
        if (val & PSR_EVENT_WD_TIMER_EXPIRE)
                DRM_DEBUG_KMS("\tPSR watchdog timer expired\n");
        if (val & PSR_EVENT_PIPE_REGISTERS_UPDATE)
                DRM_DEBUG_KMS("\tPIPE registers updated\n");
        if (val & PSR_EVENT_REGISTER_UPDATE)
                DRM_DEBUG_KMS("\tRegister updated\n");
        if (val & PSR_EVENT_HDCP_ENABLE)
                DRM_DEBUG_KMS("\tHDCP enabled\n");
        if (val & PSR_EVENT_KVMR_SESSION_ENABLE)
                DRM_DEBUG_KMS("\tKVMR session enabled\n");
        if (val & PSR_EVENT_VBI_ENABLE)
                DRM_DEBUG_KMS("\tVBI enabled\n");
        if (val & PSR_EVENT_LPSP_MODE_EXIT)
                DRM_DEBUG_KMS("\tLPSP mode exited\n");
        if ((val & PSR_EVENT_PSR_DISABLE) && !psr2_enabled)
                DRM_DEBUG_KMS("\tPSR disabled\n");
}

void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
{
        u32 transcoders = BIT(TRANSCODER_EDP);
        enum transcoder cpu_transcoder;
        ktime_t time_ns =  ktime_get();

        if (INTEL_GEN(dev_priv) >= 8)
                transcoders |= BIT(TRANSCODER_A) |
                               BIT(TRANSCODER_B) |
                               BIT(TRANSCODER_C);

        for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders) {
                /* FIXME: Exit PSR and link train manually when this happens. */
                if (psr_iir & EDP_PSR_ERROR(cpu_transcoder))
                        DRM_DEBUG_KMS("[transcoder %s] PSR aux error\n",
                                      transcoder_name(cpu_transcoder));

                if (psr_iir & EDP_PSR_PRE_ENTRY(cpu_transcoder)) {
                        dev_priv->psr.last_entry_attempt = time_ns;
                        DRM_DEBUG_KMS("[transcoder %s] PSR entry attempt in 2 vblanks\n",
                                      transcoder_name(cpu_transcoder));
                }

                if (psr_iir & EDP_PSR_POST_EXIT(cpu_transcoder)) {
                        dev_priv->psr.last_exit = time_ns;
                        DRM_DEBUG_KMS("[transcoder %s] PSR exit completed\n",
                                      transcoder_name(cpu_transcoder));

                        if (INTEL_GEN(dev_priv) >= 9) {
                                u32 val = I915_READ(PSR_EVENT(cpu_transcoder));
                                bool psr2_enabled = dev_priv->psr.psr2_enabled;

                                I915_WRITE(PSR_EVENT(cpu_transcoder), val);
                                psr_event_print(val, psr2_enabled);
                        }
                }
        }
}

static bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
{
        uint8_t dprx = 0;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_DPRX_FEATURE_ENUMERATION_LIST,
                              &dprx) != 1)
                return false;
        return dprx & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED;
}

static bool intel_dp_get_alpm_status(struct intel_dp *intel_dp)
{
        uint8_t alpm_caps = 0;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP,
                              &alpm_caps) != 1)
                return false;
        return alpm_caps & DP_ALPM_CAP;
}

static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
{
        u8 val = 8; /* assume the worst if we can't read the value */

        if (drm_dp_dpcd_readb(&intel_dp->aux,
                              DP_SYNCHRONIZATION_LATENCY_IN_SINK, &val) == 1)
                val &= DP_MAX_RESYNC_FRAME_COUNT_MASK;
        else
                DRM_DEBUG_KMS("Unable to get sink synchronization latency, assuming 8 frames\n");
        return val;
}

void intel_psr_init_dpcd(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv =
                to_i915(dp_to_dig_port(intel_dp)->base.base.dev);

        drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT, intel_dp->psr_dpcd,
                         sizeof(intel_dp->psr_dpcd));

        if (!intel_dp->psr_dpcd[0])
                return;
        DRM_DEBUG_KMS("eDP panel supports PSR version %x\n",
                      intel_dp->psr_dpcd[0]);

        if (!(intel_dp->edp_dpcd[1] & DP_EDP_SET_POWER_CAP)) {
                DRM_DEBUG_KMS("Panel lacks power state control, PSR cannot be enabled\n");
                return;
        }
        dev_priv->psr.sink_support = true;
        dev_priv->psr.sink_sync_latency =
                intel_dp_get_sink_sync_latency(intel_dp);

        WARN_ON(dev_priv->psr.dp);
        dev_priv->psr.dp = intel_dp;

        if (INTEL_GEN(dev_priv) >= 9 &&
            (intel_dp->psr_dpcd[0] == DP_PSR2_WITH_Y_COORD_IS_SUPPORTED)) {
                bool y_req = intel_dp->psr_dpcd[1] &
                             DP_PSR2_SU_Y_COORDINATE_REQUIRED;
                bool alpm = intel_dp_get_alpm_status(intel_dp);

                /*
                 * All panels that supports PSR version 03h (PSR2 +
                 * Y-coordinate) can handle Y-coordinates in VSC but we are
                 * only sure that it is going to be used when required by the
                 * panel. This way panel is capable to do selective update
                 * without a aux frame sync.
                 *
                 * To support PSR version 02h and PSR version 03h without
                 * Y-coordinate requirement panels we would need to enable
                 * GTC first.
                 */
                dev_priv->psr.sink_psr2_support = y_req && alpm;
                DRM_DEBUG_KMS("PSR2 %ssupported\n",
                              dev_priv->psr.sink_psr2_support ? "" : "not ");

                if (dev_priv->psr.sink_psr2_support) {
                        dev_priv->psr.colorimetry_support =
                                intel_dp_get_colorimetry_status(intel_dp);
                }
        }
}

static void intel_psr_setup_vsc(struct intel_dp *intel_dp,
                                const struct intel_crtc_state *crtc_state)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct edp_vsc_psr psr_vsc;

        if (dev_priv->psr.psr2_enabled) {
                /* Prepare VSC Header for SU as per EDP 1.4 spec, Table 6.11 */
                memset(&psr_vsc, 0, sizeof(psr_vsc));
                psr_vsc.sdp_header.HB0 = 0;
                psr_vsc.sdp_header.HB1 = 0x7;
                if (dev_priv->psr.colorimetry_support) {
                        psr_vsc.sdp_header.HB2 = 0x5;
                        psr_vsc.sdp_header.HB3 = 0x13;
                } else {
                        psr_vsc.sdp_header.HB2 = 0x4;
                        psr_vsc.sdp_header.HB3 = 0xe;
                }
        } else {
                /* Prepare VSC packet as per EDP 1.3 spec, Table 3.10 */
                memset(&psr_vsc, 0, sizeof(psr_vsc));
                psr_vsc.sdp_header.HB0 = 0;
                psr_vsc.sdp_header.HB1 = 0x7;
                psr_vsc.sdp_header.HB2 = 0x2;
                psr_vsc.sdp_header.HB3 = 0x8;
        }

        intel_dig_port->write_infoframe(&intel_dig_port->base.base, crtc_state,
                                        DP_SDP_VSC, &psr_vsc, sizeof(psr_vsc));
}

static void hsw_psr_setup_aux(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 aux_clock_divider, aux_ctl;
        int i;
        static const uint8_t aux_msg[] = {
                [0] = DP_AUX_NATIVE_WRITE << 4,
                [1] = DP_SET_POWER >> 8,
                [2] = DP_SET_POWER & 0xff,
                [3] = 1 - 1,
                [4] = DP_SET_POWER_D0,
        };
        u32 psr_aux_mask = EDP_PSR_AUX_CTL_TIME_OUT_MASK |
                           EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK |
                           EDP_PSR_AUX_CTL_PRECHARGE_2US_MASK |
                           EDP_PSR_AUX_CTL_BIT_CLOCK_2X_MASK;

        BUILD_BUG_ON(sizeof(aux_msg) > 20);
        for (i = 0; i < sizeof(aux_msg); i += 4)
                I915_WRITE(EDP_PSR_AUX_DATA(i >> 2),
                           intel_dp_pack_aux(&aux_msg[i], sizeof(aux_msg) - i));

        aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, 0);

        /* Start with bits set for DDI_AUX_CTL register */
        aux_ctl = intel_dp->get_aux_send_ctl(intel_dp, sizeof(aux_msg),
                                             aux_clock_divider);

        /* Select only valid bits for SRD_AUX_CTL */
        aux_ctl &= psr_aux_mask;
        I915_WRITE(EDP_PSR_AUX_CTL, aux_ctl);
}

static void intel_psr_enable_sink(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u8 dpcd_val = DP_PSR_ENABLE;

        /* Enable ALPM at sink for psr2 */
        if (dev_priv->psr.psr2_enabled) {
                drm_dp_dpcd_writeb(&intel_dp->aux, DP_RECEIVER_ALPM_CONFIG,
                                   DP_ALPM_ENABLE);
                dpcd_val |= DP_PSR_ENABLE_PSR2;
        }

        if (dev_priv->psr.link_standby)
                dpcd_val |= DP_PSR_MAIN_LINK_ACTIVE;
        if (!dev_priv->psr.psr2_enabled && INTEL_GEN(dev_priv) >= 8)
                dpcd_val |= DP_PSR_CRC_VERIFICATION;
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, dpcd_val);

        drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
}

static void hsw_activate_psr1(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 max_sleep_time = 0x1f;
        u32 val = EDP_PSR_ENABLE;

        /* Let's use 6 as the minimum to cover all known cases including the
         * off-by-one issue that HW has in some cases.
         */
        int idle_frames = max(6, dev_priv->vbt.psr.idle_frames);

        /* sink_sync_latency of 8 means source has to wait for more than 8
         * frames, we'll go with 9 frames for now
         */
        idle_frames = max(idle_frames, dev_priv->psr.sink_sync_latency + 1);
        val |= idle_frames << EDP_PSR_IDLE_FRAME_SHIFT;

        val |= max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT;
        if (IS_HASWELL(dev_priv))
                val |= EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES;

        if (dev_priv->psr.link_standby)
                val |= EDP_PSR_LINK_STANDBY;

        if (dev_priv->vbt.psr.tp1_wakeup_time_us == 0)
                val |=  EDP_PSR_TP1_TIME_0us;
        else if (dev_priv->vbt.psr.tp1_wakeup_time_us <= 100)
                val |= EDP_PSR_TP1_TIME_100us;
        else if (dev_priv->vbt.psr.tp1_wakeup_time_us <= 500)
                val |= EDP_PSR_TP1_TIME_500us;
        else
                val |= EDP_PSR_TP1_TIME_2500us;

        if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us == 0)
                val |=  EDP_PSR_TP2_TP3_TIME_0us;
        else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 100)
                val |= EDP_PSR_TP2_TP3_TIME_100us;
        else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 500)
                val |= EDP_PSR_TP2_TP3_TIME_500us;
        else
                val |= EDP_PSR_TP2_TP3_TIME_2500us;

        if (intel_dp_source_supports_hbr2(intel_dp) &&
            drm_dp_tps3_supported(intel_dp->dpcd))
                val |= EDP_PSR_TP1_TP3_SEL;
        else
                val |= EDP_PSR_TP1_TP2_SEL;

        if (INTEL_GEN(dev_priv) >= 8)
                val |= EDP_PSR_CRC_ENABLE;

        val |= I915_READ(EDP_PSR_CTL) & EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK;
        I915_WRITE(EDP_PSR_CTL, val);
}

static void hsw_activate_psr2(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 val;

        /* Let's use 6 as the minimum to cover all known cases including the
         * off-by-one issue that HW has in some cases.
         */
        int idle_frames = max(6, dev_priv->vbt.psr.idle_frames);

        idle_frames = max(idle_frames, dev_priv->psr.sink_sync_latency + 1);
        val = idle_frames << EDP_PSR2_IDLE_FRAME_SHIFT;

        /* FIXME: selective update is probably totally broken because it doesn't
         * mesh at all with our frontbuffer tracking. And the hw alone isn't
         * good enough. */
        val |= EDP_PSR2_ENABLE | EDP_SU_TRACK_ENABLE;
        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
                val |= EDP_Y_COORDINATE_ENABLE;

        val |= EDP_PSR2_FRAME_BEFORE_SU(dev_priv->psr.sink_sync_latency + 1);

        if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us >= 0 &&
            dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 50)
                val |= EDP_PSR2_TP2_TIME_50us;
        else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 100)
                val |= EDP_PSR2_TP2_TIME_100us;
        else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 500)
                val |= EDP_PSR2_TP2_TIME_500us;
        else
                val |= EDP_PSR2_TP2_TIME_2500us;

        I915_WRITE(EDP_PSR2_CTL, val);
}

static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
                                    struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        int crtc_hdisplay = crtc_state->base.adjusted_mode.crtc_hdisplay;
        int crtc_vdisplay = crtc_state->base.adjusted_mode.crtc_vdisplay;
        int psr_max_h = 0, psr_max_v = 0;

        /*
         * FIXME psr2_support is messed up. It's both computed
         * dynamically during PSR enable, and extracted from sink
         * caps during eDP detection.
         */
        if (!dev_priv->psr.sink_psr2_support)
                return false;

        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
                psr_max_h = 4096;
                psr_max_v = 2304;
        } else if (IS_GEN9(dev_priv)) {
                psr_max_h = 3640;
                psr_max_v = 2304;
        }

        if (crtc_hdisplay > psr_max_h || crtc_vdisplay > psr_max_v) {
                DRM_DEBUG_KMS("PSR2 not enabled, resolution %dx%d > max supported %dx%d\n",
                              crtc_hdisplay, crtc_vdisplay,
                              psr_max_h, psr_max_v);
                return false;
        }

        return true;
}

void intel_psr_compute_config(struct intel_dp *intel_dp,
                              struct intel_crtc_state *crtc_state)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        const struct drm_display_mode *adjusted_mode =
                &crtc_state->base.adjusted_mode;
        int psr_setup_time;

        if (!CAN_PSR(dev_priv))
                return;

        if (intel_dp != dev_priv->psr.dp)
                return;

        /*
         * HSW spec explicitly says PSR is tied to port A.
         * BDW+ platforms with DDI implementation of PSR have different
         * PSR registers per transcoder and we only implement transcoder EDP
         * ones. Since by Display design transcoder EDP is tied to port A
         * we can safely escape based on the port A.
         */
        if (dig_port->base.port != PORT_A) {
                DRM_DEBUG_KMS("PSR condition failed: Port not supported\n");
                return;
        }

        if (IS_HASWELL(dev_priv) &&
            I915_READ(HSW_STEREO_3D_CTL(crtc_state->cpu_transcoder)) &
                      S3D_ENABLE) {
                DRM_DEBUG_KMS("PSR condition failed: Stereo 3D is Enabled\n");
                return;
        }

        if (IS_HASWELL(dev_priv) &&
            adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) {
                DRM_DEBUG_KMS("PSR condition failed: Interlaced is Enabled\n");
                return;
        }

        psr_setup_time = drm_dp_psr_setup_time(intel_dp->psr_dpcd);
        if (psr_setup_time < 0) {
                DRM_DEBUG_KMS("PSR condition failed: Invalid PSR setup time (0x%02x)\n",
                              intel_dp->psr_dpcd[1]);
                return;
        }

        if (intel_usecs_to_scanlines(adjusted_mode, psr_setup_time) >
            adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay - 1) {
                DRM_DEBUG_KMS("PSR condition failed: PSR setup time (%d us) too long\n",
                              psr_setup_time);
                return;
        }

        crtc_state->has_psr = true;
        crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp, crtc_state);
}

static void intel_psr_activate(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (INTEL_GEN(dev_priv) >= 9)
                WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
        WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE);
        WARN_ON(dev_priv->psr.active);
        lockdep_assert_held(&dev_priv->psr.lock);

        /* psr1 and psr2 are mutually exclusive.*/
        if (dev_priv->psr.psr2_enabled)
                hsw_activate_psr2(intel_dp);
        else
                hsw_activate_psr1(intel_dp);

        dev_priv->psr.active = true;
}

static void intel_psr_enable_source(struct intel_dp *intel_dp,
                                    const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;

        /* Only HSW and BDW have PSR AUX registers that need to be setup. SKL+
         * use hardcoded values PSR AUX transactions
         */
        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                hsw_psr_setup_aux(intel_dp);

        if (dev_priv->psr.psr2_enabled) {
                u32 chicken = I915_READ(CHICKEN_TRANS(cpu_transcoder));

                if (INTEL_GEN(dev_priv) == 9 && !IS_GEMINILAKE(dev_priv))
                        chicken |= (PSR2_VSC_ENABLE_PROG_HEADER
                                   | PSR2_ADD_VERTICAL_LINE_COUNT);

                else
                        chicken &= ~VSC_DATA_SEL_SOFTWARE_CONTROL;
                I915_WRITE(CHICKEN_TRANS(cpu_transcoder), chicken);

                I915_WRITE(EDP_PSR_DEBUG,
                           EDP_PSR_DEBUG_MASK_MEMUP |
                           EDP_PSR_DEBUG_MASK_HPD |
                           EDP_PSR_DEBUG_MASK_LPSP |
                           EDP_PSR_DEBUG_MASK_MAX_SLEEP |
                           EDP_PSR_DEBUG_MASK_DISP_REG_WRITE);
        } else {
                /*
                 * Per Spec: Avoid continuous PSR exit by masking MEMUP
                 * and HPD. also mask LPSP to avoid dependency on other
                 * drivers that might block runtime_pm besides
                 * preventing  other hw tracking issues now we can rely
                 * on frontbuffer tracking.
                 */
                I915_WRITE(EDP_PSR_DEBUG,
                           EDP_PSR_DEBUG_MASK_MEMUP |
                           EDP_PSR_DEBUG_MASK_HPD |
                           EDP_PSR_DEBUG_MASK_LPSP |
                           EDP_PSR_DEBUG_MASK_DISP_REG_WRITE |
                           EDP_PSR_DEBUG_MASK_MAX_SLEEP);
        }
}

static void intel_psr_enable_locked(struct drm_i915_private *dev_priv,
                                    const struct intel_crtc_state *crtc_state)
{
        struct intel_dp *intel_dp = dev_priv->psr.dp;

        if (dev_priv->psr.enabled)
                return;

        DRM_DEBUG_KMS("Enabling PSR%s\n",
                      dev_priv->psr.psr2_enabled ? "2" : "1");
        intel_psr_setup_vsc(intel_dp, crtc_state);
        intel_psr_enable_sink(intel_dp);
        intel_psr_enable_source(intel_dp, crtc_state);
        dev_priv->psr.enabled = true;

        intel_psr_activate(intel_dp);
}

/**
 * intel_psr_enable - Enable PSR
 * @intel_dp: Intel DP
 * @crtc_state: new CRTC state
 *
 * This function can only be called after the pipe is fully trained and enabled.
 */
void intel_psr_enable(struct intel_dp *intel_dp,
                      const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (!crtc_state->has_psr)
                return;

        if (WARN_ON(!CAN_PSR(dev_priv)))
                return;

        WARN_ON(dev_priv->drrs.dp);

        mutex_lock(&dev_priv->psr.lock);
        if (dev_priv->psr.prepared) {
                DRM_DEBUG_KMS("PSR already in use\n");
                goto unlock;
        }

        dev_priv->psr.psr2_enabled = intel_psr2_enabled(dev_priv, crtc_state);
        dev_priv->psr.busy_frontbuffer_bits = 0;
        dev_priv->psr.prepared = true;

        if (psr_global_enabled(dev_priv->psr.debug))
                intel_psr_enable_locked(dev_priv, crtc_state);
        else
                DRM_DEBUG_KMS("PSR disabled by flag\n");

unlock:
        mutex_unlock(&dev_priv->psr.lock);
}

static void
intel_psr_disable_source(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (dev_priv->psr.active) {
                i915_reg_t psr_status;
                u32 psr_status_mask;

                if (dev_priv->psr.psr2_enabled) {
                        psr_status = EDP_PSR2_STATUS;
                        psr_status_mask = EDP_PSR2_STATUS_STATE_MASK;

                        I915_WRITE(EDP_PSR2_CTL,
                                   I915_READ(EDP_PSR2_CTL) &
                                   ~(EDP_PSR2_ENABLE | EDP_SU_TRACK_ENABLE));

                } else {
                        psr_status = EDP_PSR_STATUS;
                        psr_status_mask = EDP_PSR_STATUS_STATE_MASK;

                        I915_WRITE(EDP_PSR_CTL,
                                   I915_READ(EDP_PSR_CTL) & ~EDP_PSR_ENABLE);
                }

                /* Wait till PSR is idle */
                if (intel_wait_for_register(dev_priv,
                                            psr_status, psr_status_mask, 0,
                                            2000))
                        DRM_ERROR("Timed out waiting for PSR Idle State\n");

                dev_priv->psr.active = false;
        } else {
                if (dev_priv->psr.psr2_enabled)
                        WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
                else
                        WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE);
        }
}

static void intel_psr_disable_locked(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        lockdep_assert_held(&dev_priv->psr.lock);

        if (!dev_priv->psr.enabled)
                return;

        DRM_DEBUG_KMS("Disabling PSR%s\n",
                      dev_priv->psr.psr2_enabled ? "2" : "1");
        intel_psr_disable_source(intel_dp);

        /* Disable PSR on Sink */
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);

        dev_priv->psr.enabled = false;
}

/**
 * intel_psr_disable - Disable PSR
 * @intel_dp: Intel DP
 * @old_crtc_state: old CRTC state
 *
 * This function needs to be called before disabling pipe.
 */
void intel_psr_disable(struct intel_dp *intel_dp,
                       const struct intel_crtc_state *old_crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (!old_crtc_state->has_psr)
                return;

        if (WARN_ON(!CAN_PSR(dev_priv)))
                return;

        mutex_lock(&dev_priv->psr.lock);
        if (!dev_priv->psr.prepared) {
                mutex_unlock(&dev_priv->psr.lock);
                return;
        }

        intel_psr_disable_locked(intel_dp);

        dev_priv->psr.prepared = false;
        mutex_unlock(&dev_priv->psr.lock);
        cancel_work_sync(&dev_priv->psr.work);
}

/**
 * intel_psr_wait_for_idle - wait for PSR1 to idle
 * @new_crtc_state: new CRTC state
 * @out_value: PSR status in case of failure
 *
 * This function is expected to be called from pipe_update_start() where it is
 * not expected to race with PSR enable or disable.
 *
 * Returns: 0 on success or -ETIMEOUT if PSR status does not idle.
 */
int intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state,
                            u32 *out_value)
{
        struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->base.crtc);
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

        if (!dev_priv->psr.enabled || !new_crtc_state->has_psr)
                return 0;

        /* FIXME: Update this for PSR2 if we need to wait for idle */
        if (READ_ONCE(dev_priv->psr.psr2_enabled))
                return 0;

        /*
         * From bspec: Panel Self Refresh (BDW+)
         * Max. time for PSR to idle = Inverse of the refresh rate + 6 ms of
         * exit training time + 1.5 ms of aux channel handshake. 50 ms is
         * defensive enough to cover everything.
         */

        return __intel_wait_for_register(dev_priv, EDP_PSR_STATUS,
                                         EDP_PSR_STATUS_STATE_MASK,
                                         EDP_PSR_STATUS_STATE_IDLE, 2, 50,
                                         out_value);
}

static bool __psr_wait_for_idle_locked(struct drm_i915_private *dev_priv)
{
        i915_reg_t reg;
        u32 mask;
        int err;

        if (!dev_priv->psr.enabled)
                return false;

        if (dev_priv->psr.psr2_enabled) {
                reg = EDP_PSR2_STATUS;
                mask = EDP_PSR2_STATUS_STATE_MASK;
        } else {
                reg = EDP_PSR_STATUS;
                mask = EDP_PSR_STATUS_STATE_MASK;
        }

        mutex_unlock(&dev_priv->psr.lock);

        err = intel_wait_for_register(dev_priv, reg, mask, 0, 50);
        if (err)
                DRM_ERROR("Timed out waiting for PSR Idle for re-enable\n");

        /* After the unlocked wait, verify that PSR is still wanted! */
        mutex_lock(&dev_priv->psr.lock);
        return err == 0 && dev_priv->psr.enabled;
}

static bool switching_psr(struct drm_i915_private *dev_priv,
                          struct intel_crtc_state *crtc_state,
                          u32 mode)
{
        /* Can't switch psr state anyway if PSR2 is not supported. */
        if (!crtc_state || !crtc_state->has_psr2)
                return false;

        if (dev_priv->psr.psr2_enabled && mode == I915_PSR_DEBUG_FORCE_PSR1)
                return true;

        if (!dev_priv->psr.psr2_enabled && mode != I915_PSR_DEBUG_FORCE_PSR1)
                return true;

        return false;
}

int intel_psr_set_debugfs_mode(struct drm_i915_private *dev_priv,
                               struct drm_modeset_acquire_ctx *ctx,
                               u64 val)
{
        struct drm_device *dev = &dev_priv->drm;
        struct drm_connector_state *conn_state;
        struct intel_crtc_state *crtc_state = NULL;
        struct drm_crtc_commit *commit;
        struct drm_crtc *crtc;
        struct intel_dp *dp;
        int ret;
        bool enable;
        u32 mode = val & I915_PSR_DEBUG_MODE_MASK;

        if (val & ~(I915_PSR_DEBUG_IRQ | I915_PSR_DEBUG_MODE_MASK) ||
            mode > I915_PSR_DEBUG_FORCE_PSR1) {
                DRM_DEBUG_KMS("Invalid debug mask %llx\n", val);
                return -EINVAL;
        }

        ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
        if (ret)
                return ret;

        /* dev_priv->psr.dp should be set once and then never touched again. */
        dp = READ_ONCE(dev_priv->psr.dp);
        conn_state = dp->attached_connector->base.state;
        crtc = conn_state->crtc;
        if (crtc) {
                ret = drm_modeset_lock(&crtc->mutex, ctx);
                if (ret)
                        return ret;

                crtc_state = to_intel_crtc_state(crtc->state);
                commit = crtc_state->base.commit;
        } else {
                commit = conn_state->commit;
        }
        if (commit) {
                ret = wait_for_completion_interruptible(&commit->hw_done);
                if (ret)
                        return ret;
        }

        ret = mutex_lock_interruptible(&dev_priv->psr.lock);
        if (ret)
                return ret;

        enable = psr_global_enabled(val);

        if (!enable || switching_psr(dev_priv, crtc_state, mode))
                intel_psr_disable_locked(dev_priv->psr.dp);

        dev_priv->psr.debug = val;
        if (crtc)
                dev_priv->psr.psr2_enabled = intel_psr2_enabled(dev_priv, crtc_state);

        intel_psr_irq_control(dev_priv, dev_priv->psr.debug);

        if (dev_priv->psr.prepared && enable)
                intel_psr_enable_locked(dev_priv, crtc_state);

        mutex_unlock(&dev_priv->psr.lock);
        return ret;
}

static void intel_psr_work(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, typeof(*dev_priv), psr.work);

        mutex_lock(&dev_priv->psr.lock);

        if (!dev_priv->psr.enabled)
                goto unlock;

        /*
         * We have to make sure PSR is ready for re-enable
         * otherwise it keeps disabled until next full enable/disable cycle.
         * PSR might take some time to get fully disabled
         * and be ready for re-enable.
         */
        if (!__psr_wait_for_idle_locked(dev_priv))
                goto unlock;

        /*
         * The delayed work can race with an invalidate hence we need to
         * recheck. Since psr_flush first clears this and then reschedules we
         * won't ever miss a flush when bailing out here.
         */
        if (dev_priv->psr.busy_frontbuffer_bits || dev_priv->psr.active)
                goto unlock;

        intel_psr_activate(dev_priv->psr.dp);
unlock:
        mutex_unlock(&dev_priv->psr.lock);
}

static void intel_psr_exit(struct drm_i915_private *dev_priv)
{
        u32 val;

        if (!dev_priv->psr.active)
                return;

        if (dev_priv->psr.psr2_enabled) {
                val = I915_READ(EDP_PSR2_CTL);
                WARN_ON(!(val & EDP_PSR2_ENABLE));
                I915_WRITE(EDP_PSR2_CTL, val & ~EDP_PSR2_ENABLE);
        } else {
                val = I915_READ(EDP_PSR_CTL);
                WARN_ON(!(val & EDP_PSR_ENABLE));
                I915_WRITE(EDP_PSR_CTL, val & ~EDP_PSR_ENABLE);
        }
        dev_priv->psr.active = false;
}

/**
 * intel_psr_invalidate - Invalidade PSR
 * @dev_priv: i915 device
 * @frontbuffer_bits: frontbuffer plane tracking bits
 * @origin: which operation caused the invalidate
 *
 * Since the hardware frontbuffer tracking has gaps we need to integrate
 * with the software frontbuffer tracking. This function gets called every
 * time frontbuffer rendering starts and a buffer gets dirtied. PSR must be
 * disabled if the frontbuffer mask contains a buffer relevant to PSR.
 *
 * Dirty frontbuffers relevant to PSR are tracked in busy_frontbuffer_bits."
 */
void intel_psr_invalidate(struct drm_i915_private *dev_priv,
                          unsigned frontbuffer_bits, enum fb_op_origin origin)
{
        struct drm_crtc *crtc;
        enum pipe pipe;

        if (!CAN_PSR(dev_priv))
                return;

        if (origin == ORIGIN_FLIP)
                return;

        mutex_lock(&dev_priv->psr.lock);
        if (!dev_priv->psr.enabled) {
                mutex_unlock(&dev_priv->psr.lock);
                return;
        }

        crtc = dp_to_dig_port(dev_priv->psr.dp)->base.base.crtc;
        pipe = to_intel_crtc(crtc)->pipe;

        frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
        dev_priv->psr.busy_frontbuffer_bits |= frontbuffer_bits;

        if (frontbuffer_bits)
                intel_psr_exit(dev_priv);

        mutex_unlock(&dev_priv->psr.lock);
}

/**
 * intel_psr_flush - Flush PSR
 * @dev_priv: i915 device
 * @frontbuffer_bits: frontbuffer plane tracking bits
 * @origin: which operation caused the flush
 *
 * Since the hardware frontbuffer tracking has gaps we need to integrate
 * with the software frontbuffer tracking. This function gets called every
 * time frontbuffer rendering has completed and flushed out to memory. PSR
 * can be enabled again if no other frontbuffer relevant to PSR is dirty.
 *

 * Dirty frontbuffers relevant to PSR are tracked in busy_frontbuffer_bits.
 */
void intel_psr_flush(struct drm_i915_private *dev_priv,
                     unsigned frontbuffer_bits, enum fb_op_origin origin)
{
        struct drm_crtc *crtc;
        enum pipe pipe;

        if (!CAN_PSR(dev_priv))
                return;

        if (origin == ORIGIN_FLIP)
                return;

        mutex_lock(&dev_priv->psr.lock);
        if (!dev_priv->psr.enabled) {
                mutex_unlock(&dev_priv->psr.lock);
                return;
        }

        crtc = dp_to_dig_port(dev_priv->psr.dp)->base.base.crtc;
        pipe = to_intel_crtc(crtc)->pipe;

        frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
        dev_priv->psr.busy_frontbuffer_bits &= ~frontbuffer_bits;

        /* By definition flush = invalidate + flush */
        if (frontbuffer_bits) {
                if (dev_priv->psr.psr2_enabled) {
                        intel_psr_exit(dev_priv);
                } else {
                        /*
                         * Display WA #0884: all
                         * This documented WA for bxt can be safely applied
                         * broadly so we can force HW tracking to exit PSR
                         * instead of disabling and re-enabling.
                         * Workaround tells us to write 0 to CUR_SURFLIVE_A,
                         * but it makes more sense write to the current active
                         * pipe.
                         */
                        I915_WRITE(CURSURFLIVE(pipe), 0);
                }
        }

        if (!dev_priv->psr.active && !dev_priv->psr.busy_frontbuffer_bits)
                schedule_work(&dev_priv->psr.work);
        mutex_unlock(&dev_priv->psr.lock);
}

/**
 * intel_psr_init - Init basic PSR work and mutex.
 * @dev_priv: i915 device private
 *
 * This function is  called only once at driver load to initialize basic
 * PSR stuff.
 */
void intel_psr_init(struct drm_i915_private *dev_priv)
{
        if (!HAS_PSR(dev_priv))
                return;

        dev_priv->psr_mmio_base = IS_HASWELL(dev_priv) ?
                HSW_EDP_PSR_BASE : BDW_EDP_PSR_BASE;

        if (!dev_priv->psr.sink_support)
                return;

        if (i915_modparams.enable_psr == -1) {
                i915_modparams.enable_psr = dev_priv->vbt.psr.enable;

                /* Per platform default: all disabled. */
                i915_modparams.enable_psr = 0;
        }

        /* Set link_standby x link_off defaults */
        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                /* HSW and BDW require workarounds that we don't implement. */
                dev_priv->psr.link_standby = false;
        else
                /* For new platforms let's respect VBT back again */
                dev_priv->psr.link_standby = dev_priv->vbt.psr.full_link;

        INIT_WORK(&dev_priv->psr.work, intel_psr_work);
        mutex_init(&dev_priv->psr.lock);
}

void intel_psr_short_pulse(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct i915_psr *psr = &dev_priv->psr;
        u8 val;
        const u8 errors = DP_PSR_RFB_STORAGE_ERROR |
                          DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR |
                          DP_PSR_LINK_CRC_ERROR;

        if (!CAN_PSR(dev_priv) || !intel_dp_is_edp(intel_dp))
                return;

        mutex_lock(&psr->lock);

        if (!psr->enabled || psr->dp != intel_dp)
                goto exit;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS, &val) != 1) {
                DRM_ERROR("PSR_STATUS dpcd read failed\n");
                goto exit;
        }

        if ((val & DP_PSR_SINK_STATE_MASK) == DP_PSR_SINK_INTERNAL_ERROR) {
                DRM_DEBUG_KMS("PSR sink internal error, disabling PSR\n");
                intel_psr_disable_locked(intel_dp);
        }

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_ERROR_STATUS, &val) != 1) {
                DRM_ERROR("PSR_ERROR_STATUS dpcd read failed\n");
                goto exit;
        }

        if (val & DP_PSR_RFB_STORAGE_ERROR)
                DRM_DEBUG_KMS("PSR RFB storage error, disabling PSR\n");
        if (val & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
                DRM_DEBUG_KMS("PSR VSC SDP uncorrectable error, disabling PSR\n");
        if (val & DP_PSR_LINK_CRC_ERROR)
                DRM_ERROR("PSR Link CRC error, disabling PSR\n");

        if (val & ~errors)
                DRM_ERROR("PSR_ERROR_STATUS unhandled errors %x\n",
                          val & ~errors);
        if (val & errors)
                intel_psr_disable_locked(intel_dp);
        /* clear status register */
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS, val);

        /* TODO: handle PSR2 errors */
exit:
        mutex_unlock(&psr->lock);
}