// SPDX-License-Identifier: MIT
/*
 * Copyright © 2020-2021 Intel Corporation
 */

#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_display_types.h"
#include "intel_dp_aux.h"
#include "intel_pps.h"
#include "intel_tc.h"

u32 intel_dp_pack_aux(const u8 *src, int src_bytes)
{
        int i;
        u32 v = 0;

        if (src_bytes > 4)
                src_bytes = 4;
        for (i = 0; i < src_bytes; i++)
                v |= ((u32)src[i]) << ((3 - i) * 8);
        return v;
}

static void intel_dp_unpack_aux(u32 src, u8 *dst, int dst_bytes)
{
        int i;

        if (dst_bytes > 4)
                dst_bytes = 4;
        for (i = 0; i < dst_bytes; i++)
                dst[i] = src >> ((3 - i) * 8);
}

static u32
intel_dp_aux_wait_done(struct intel_dp *intel_dp)
{
        struct drm_i915_private *i915 = dp_to_i915(intel_dp);
        i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
        const unsigned int timeout_ms = 10;
        u32 status;
        bool done;

#define C (((status = intel_uncore_read_notrace(&i915->uncore, ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
        done = wait_event_timeout(i915->gmbus_wait_queue, C,
                                  msecs_to_jiffies_timeout(timeout_ms));

        /* just trace the final value */
        trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);

        if (!done)
                drm_err(&i915->drm,
                        "%s: did not complete or timeout within %ums (status 0x%08x)\n",
                        intel_dp->aux.name, timeout_ms, status);
#undef C

        return status;
}

static u32 g4x_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (index)
                return 0;

        /*
         * The clock divider is based off the hrawclk, and would like to run at
         * 2MHz.  So, take the hrawclk value and divide by 2000 and use that
         */
        return DIV_ROUND_CLOSEST(RUNTIME_INFO(dev_priv)->rawclk_freq, 2000);
}

static u32 ilk_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        u32 freq;

        if (index)
                return 0;

        /*
         * The clock divider is based off the cdclk or PCH rawclk, and would
         * like to run at 2MHz.  So, take the cdclk or PCH rawclk value and
         * divide by 2000 and use that
         */
        if (dig_port->aux_ch == AUX_CH_A)
                freq = dev_priv->cdclk.hw.cdclk;
        else
                freq = RUNTIME_INFO(dev_priv)->rawclk_freq;
        return DIV_ROUND_CLOSEST(freq, 2000);
}

static u32 hsw_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);

        if (dig_port->aux_ch != AUX_CH_A && HAS_PCH_LPT_H(dev_priv)) {
                /* Workaround for non-ULT HSW */
                switch (index) {
                case 0: return 63;
                case 1: return 72;
                default: return 0;
                }
        }

        return ilk_get_aux_clock_divider(intel_dp, index);
}

static u32 skl_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        /*
         * SKL doesn't need us to program the AUX clock divider (Hardware will
         * derive the clock from CDCLK automatically). We still implement the
         * get_aux_clock_divider vfunc to plug-in into the existing code.
         */
        return index ? 0 : 1;
}

static u32 g4x_get_aux_send_ctl(struct intel_dp *intel_dp,
                                int send_bytes,
                                u32 aux_clock_divider)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv =
                        to_i915(dig_port->base.base.dev);
        u32 timeout;

        /* Max timeout value on G4x-BDW: 1.6ms */
        if (IS_BROADWELL(dev_priv))
                timeout = DP_AUX_CH_CTL_TIME_OUT_600us;
        else
                timeout = DP_AUX_CH_CTL_TIME_OUT_400us;

        return DP_AUX_CH_CTL_SEND_BUSY |
               DP_AUX_CH_CTL_DONE |
               DP_AUX_CH_CTL_INTERRUPT |
               DP_AUX_CH_CTL_TIME_OUT_ERROR |
               timeout |
               DP_AUX_CH_CTL_RECEIVE_ERROR |
               (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
               (3 << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
               (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT);
}

static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
                                int send_bytes,
                                u32 unused)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *i915 =
                        to_i915(dig_port->base.base.dev);
        enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
        u32 ret;

        /*
         * Max timeout values:
         * SKL-GLK: 1.6ms
         * ICL+: 4ms
         */
        ret = DP_AUX_CH_CTL_SEND_BUSY |
              DP_AUX_CH_CTL_DONE |
              DP_AUX_CH_CTL_INTERRUPT |
              DP_AUX_CH_CTL_TIME_OUT_ERROR |
              DP_AUX_CH_CTL_TIME_OUT_MAX |
              DP_AUX_CH_CTL_RECEIVE_ERROR |
              (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
              DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(32) |
              DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);

        if (intel_phy_is_tc(i915, phy) &&
            dig_port->tc_mode == TC_PORT_TBT_ALT)
                ret |= DP_AUX_CH_CTL_TBT_IO;

        return ret;
}

static int
intel_dp_aux_xfer(struct intel_dp *intel_dp,
                  const u8 *send, int send_bytes,
                  u8 *recv, int recv_size,
                  u32 aux_send_ctl_flags)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *i915 =
                        to_i915(dig_port->base.base.dev);
        struct intel_uncore *uncore = &i915->uncore;
        enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
        bool is_tc_port = intel_phy_is_tc(i915, phy);
        i915_reg_t ch_ctl, ch_data[5];
        u32 aux_clock_divider;
        enum intel_display_power_domain aux_domain;
        intel_wakeref_t aux_wakeref;
        intel_wakeref_t pps_wakeref;
        int i, ret, recv_bytes;
        int try, clock = 0;
        u32 status;
        bool vdd;

        ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
        for (i = 0; i < ARRAY_SIZE(ch_data); i++)
                ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i);

        if (is_tc_port)
                intel_tc_port_lock(dig_port);

        aux_domain = intel_aux_power_domain(dig_port);

        aux_wakeref = intel_display_power_get(i915, aux_domain);
        pps_wakeref = intel_pps_lock(intel_dp);

        /*
         * We will be called with VDD already enabled for dpcd/edid/oui reads.
         * In such cases we want to leave VDD enabled and it's up to upper layers
         * to turn it off. But for eg. i2c-dev access we need to turn it on/off
         * ourselves.
         */
        vdd = intel_pps_vdd_on_unlocked(intel_dp);

        /*
         * dp aux is extremely sensitive to irq latency, hence request the
         * lowest possible wakeup latency and so prevent the cpu from going into
         * deep sleep states.
         */
        cpu_latency_qos_update_request(&intel_dp->pm_qos, 0);

        intel_pps_check_power_unlocked(intel_dp);

        /* Try to wait for any previous AUX channel activity */
        for (try = 0; try < 3; try++) {
                status = intel_uncore_read_notrace(uncore, ch_ctl);
                if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
                        break;
                msleep(1);
        }
        /* just trace the final value */
        trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);

        if (try == 3) {
                const u32 status = intel_uncore_read(uncore, ch_ctl);

                if (status != intel_dp->aux_busy_last_status) {
                        drm_WARN(&i915->drm, 1,
                                 "%s: not started (status 0x%08x)\n",
                                 intel_dp->aux.name, status);
                        intel_dp->aux_busy_last_status = status;
                }

                ret = -EBUSY;
                goto out;
        }

        /* Only 5 data registers! */
        if (drm_WARN_ON(&i915->drm, send_bytes > 20 || recv_size > 20)) {
                ret = -E2BIG;
                goto out;
        }

        while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) {
                u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
                                                          send_bytes,
                                                          aux_clock_divider);

                send_ctl |= aux_send_ctl_flags;

                /* Must try at least 3 times according to DP spec */
                for (try = 0; try < 5; try++) {
                        /* Load the send data into the aux channel data registers */
                        for (i = 0; i < send_bytes; i += 4)
                                intel_uncore_write(uncore,
                                                   ch_data[i >> 2],
                                                   intel_dp_pack_aux(send + i,
                                                                     send_bytes - i));

                        /* Send the command and wait for it to complete */
                        intel_uncore_write(uncore, ch_ctl, send_ctl);

                        status = intel_dp_aux_wait_done(intel_dp);

                        /* Clear done status and any errors */
                        intel_uncore_write(uncore,
                                           ch_ctl,
                                           status |
                                           DP_AUX_CH_CTL_DONE |
                                           DP_AUX_CH_CTL_TIME_OUT_ERROR |
                                           DP_AUX_CH_CTL_RECEIVE_ERROR);

                        /*
                         * DP CTS 1.2 Core Rev 1.1, 4.2.1.1 & 4.2.1.2
                         *   400us delay required for errors and timeouts
                         *   Timeout errors from the HW already meet this
                         *   requirement so skip to next iteration
                         */
                        if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR)
                                continue;

                        if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
                                usleep_range(400, 500);
                                continue;
                        }
                        if (status & DP_AUX_CH_CTL_DONE)
                                goto done;
                }
        }

        if ((status & DP_AUX_CH_CTL_DONE) == 0) {
                drm_err(&i915->drm, "%s: not done (status 0x%08x)\n",
                        intel_dp->aux.name, status);
                ret = -EBUSY;
                goto out;
        }

done:
        /*
         * Check for timeout or receive error. Timeouts occur when the sink is
         * not connected.
         */
        if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
                drm_err(&i915->drm, "%s: receive error (status 0x%08x)\n",
                        intel_dp->aux.name, status);
                ret = -EIO;
                goto out;
        }

        /*
         * Timeouts occur when the device isn't connected, so they're "normal"
         * -- don't fill the kernel log with these
         */
        if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
                drm_dbg_kms(&i915->drm, "%s: timeout (status 0x%08x)\n",
                            intel_dp->aux.name, status);
                ret = -ETIMEDOUT;
                goto out;
        }

        /* Unload any bytes sent back from the other side */
        recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
                      DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);

        /*
         * By BSpec: "Message sizes of 0 or >20 are not allowed."
         * We have no idea of what happened so we return -EBUSY so
         * drm layer takes care for the necessary retries.
         */
        if (recv_bytes == 0 || recv_bytes > 20) {
                drm_dbg_kms(&i915->drm,
                            "%s: Forbidden recv_bytes = %d on aux transaction\n",
                            intel_dp->aux.name, recv_bytes);
                ret = -EBUSY;
                goto out;
        }

        if (recv_bytes > recv_size)
                recv_bytes = recv_size;

        for (i = 0; i < recv_bytes; i += 4)
                intel_dp_unpack_aux(intel_uncore_read(uncore, ch_data[i >> 2]),
                                    recv + i, recv_bytes - i);

        ret = recv_bytes;
out:
        cpu_latency_qos_update_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);

        if (vdd)
                intel_pps_vdd_off_unlocked(intel_dp, false);

        intel_pps_unlock(intel_dp, pps_wakeref);
        intel_display_power_put_async(i915, aux_domain, aux_wakeref);

        if (is_tc_port)
                intel_tc_port_unlock(dig_port);

        return ret;
}

#define BARE_ADDRESS_SIZE       3
#define HEADER_SIZE             (BARE_ADDRESS_SIZE + 1)

static void
intel_dp_aux_header(u8 txbuf[HEADER_SIZE],
                    const struct drm_dp_aux_msg *msg)
{
        txbuf[0] = (msg->request << 4) | ((msg->address >> 16) & 0xf);
        txbuf[1] = (msg->address >> 8) & 0xff;
        txbuf[2] = msg->address & 0xff;
        txbuf[3] = msg->size - 1;
}

static u32 intel_dp_aux_xfer_flags(const struct drm_dp_aux_msg *msg)
{
        /*
         * If we're trying to send the HDCP Aksv, we need to set a the Aksv
         * select bit to inform the hardware to send the Aksv after our header
         * since we can't access that data from software.
         */
        if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_WRITE &&
            msg->address == DP_AUX_HDCP_AKSV)
                return DP_AUX_CH_CTL_AUX_AKSV_SELECT;

        return 0;
}

static ssize_t
intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
{
        struct intel_dp *intel_dp = container_of(aux, struct intel_dp, aux);
        struct drm_i915_private *i915 = dp_to_i915(intel_dp);
        u8 txbuf[20], rxbuf[20];
        size_t txsize, rxsize;
        u32 flags = intel_dp_aux_xfer_flags(msg);
        int ret;

        intel_dp_aux_header(txbuf, msg);

        switch (msg->request & ~DP_AUX_I2C_MOT) {
        case DP_AUX_NATIVE_WRITE:
        case DP_AUX_I2C_WRITE:
        case DP_AUX_I2C_WRITE_STATUS_UPDATE:
                txsize = msg->size ? HEADER_SIZE + msg->size : BARE_ADDRESS_SIZE;
                rxsize = 2; /* 0 or 1 data bytes */

                if (drm_WARN_ON(&i915->drm, txsize > 20))
                        return -E2BIG;

                drm_WARN_ON(&i915->drm, !msg->buffer != !msg->size);

                if (msg->buffer)
                        memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);

                ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
                                        rxbuf, rxsize, flags);
                if (ret > 0) {
                        msg->reply = rxbuf[0] >> 4;

                        if (ret > 1) {
                                /* Number of bytes written in a short write. */
                                ret = clamp_t(int, rxbuf[1], 0, msg->size);
                        } else {
                                /* Return payload size. */
                                ret = msg->size;
                        }
                }
                break;

        case DP_AUX_NATIVE_READ:
        case DP_AUX_I2C_READ:
                txsize = msg->size ? HEADER_SIZE : BARE_ADDRESS_SIZE;
                rxsize = msg->size + 1;

                if (drm_WARN_ON(&i915->drm, rxsize > 20))
                        return -E2BIG;

                ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
                                        rxbuf, rxsize, flags);
                if (ret > 0) {
                        msg->reply = rxbuf[0] >> 4;
                        /*
                         * Assume happy day, and copy the data. The caller is
                         * expected to check msg->reply before touching it.
                         *
                         * Return payload size.
                         */
                        ret--;
                        memcpy(msg->buffer, rxbuf + 1, ret);
                }
                break;

        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static i915_reg_t g4x_aux_ctl_reg(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_D:
                return DP_AUX_CH_CTL(aux_ch);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_CTL(AUX_CH_B);
        }
}

static i915_reg_t g4x_aux_data_reg(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_D:
                return DP_AUX_CH_DATA(aux_ch, index);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_DATA(AUX_CH_B, index);
        }
}

static i915_reg_t ilk_aux_ctl_reg(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_A:
                return DP_AUX_CH_CTL(aux_ch);
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_D:
                return PCH_DP_AUX_CH_CTL(aux_ch);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_CTL(AUX_CH_A);
        }
}

static i915_reg_t ilk_aux_data_reg(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_A:
                return DP_AUX_CH_DATA(aux_ch, index);
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_D:
                return PCH_DP_AUX_CH_DATA(aux_ch, index);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_DATA(AUX_CH_A, index);
        }
}

static i915_reg_t skl_aux_ctl_reg(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_A:
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_D:
        case AUX_CH_E:
        case AUX_CH_F:
                return DP_AUX_CH_CTL(aux_ch);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_CTL(AUX_CH_A);
        }
}

static i915_reg_t skl_aux_data_reg(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_A:
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_D:
        case AUX_CH_E:
        case AUX_CH_F:
                return DP_AUX_CH_DATA(aux_ch, index);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_DATA(AUX_CH_A, index);
        }
}

static i915_reg_t tgl_aux_ctl_reg(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_A:
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_USBC1:
        case AUX_CH_USBC2:
        case AUX_CH_USBC3:
        case AUX_CH_USBC4:
        case AUX_CH_USBC5:  /* aka AUX_CH_D_XELPD */
        case AUX_CH_USBC6:  /* aka AUX_CH_E_XELPD */
                return DP_AUX_CH_CTL(aux_ch);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_CTL(AUX_CH_A);
        }
}

static i915_reg_t tgl_aux_data_reg(struct intel_dp *intel_dp, int index)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        enum aux_ch aux_ch = dig_port->aux_ch;

        switch (aux_ch) {
        case AUX_CH_A:
        case AUX_CH_B:
        case AUX_CH_C:
        case AUX_CH_USBC1:
        case AUX_CH_USBC2:
        case AUX_CH_USBC3:
        case AUX_CH_USBC4:
        case AUX_CH_USBC5:  /* aka AUX_CH_D_XELPD */
        case AUX_CH_USBC6:  /* aka AUX_CH_E_XELPD */
                return DP_AUX_CH_DATA(aux_ch, index);
        default:
                MISSING_CASE(aux_ch);
                return DP_AUX_CH_DATA(AUX_CH_A, index);
        }
}

void intel_dp_aux_fini(struct intel_dp *intel_dp)
{
        if (cpu_latency_qos_request_active(&intel_dp->pm_qos))
                cpu_latency_qos_remove_request(&intel_dp->pm_qos);

        kfree(intel_dp->aux.name);
}

void intel_dp_aux_init(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *encoder = &dig_port->base;
        enum aux_ch aux_ch = dig_port->aux_ch;

        if (DISPLAY_VER(dev_priv) >= 12) {
                intel_dp->aux_ch_ctl_reg = tgl_aux_ctl_reg;
                intel_dp->aux_ch_data_reg = tgl_aux_data_reg;
        } else if (DISPLAY_VER(dev_priv) >= 9) {
                intel_dp->aux_ch_ctl_reg = skl_aux_ctl_reg;
                intel_dp->aux_ch_data_reg = skl_aux_data_reg;
        } else if (HAS_PCH_SPLIT(dev_priv)) {
                intel_dp->aux_ch_ctl_reg = ilk_aux_ctl_reg;
                intel_dp->aux_ch_data_reg = ilk_aux_data_reg;
        } else {
                intel_dp->aux_ch_ctl_reg = g4x_aux_ctl_reg;
                intel_dp->aux_ch_data_reg = g4x_aux_data_reg;
        }

        if (DISPLAY_VER(dev_priv) >= 9)
                intel_dp->get_aux_clock_divider = skl_get_aux_clock_divider;
        else if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
                intel_dp->get_aux_clock_divider = hsw_get_aux_clock_divider;
        else if (HAS_PCH_SPLIT(dev_priv))
                intel_dp->get_aux_clock_divider = ilk_get_aux_clock_divider;
        else
                intel_dp->get_aux_clock_divider = g4x_get_aux_clock_divider;

        if (DISPLAY_VER(dev_priv) >= 9)
                intel_dp->get_aux_send_ctl = skl_get_aux_send_ctl;
        else
                intel_dp->get_aux_send_ctl = g4x_get_aux_send_ctl;

        intel_dp->aux.drm_dev = &dev_priv->drm;
        drm_dp_aux_init(&intel_dp->aux);

        /* Failure to allocate our preferred name is not critical */
        if (DISPLAY_VER(dev_priv) >= 13 && aux_ch >= AUX_CH_D_XELPD)
                intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
                                               aux_ch_name(aux_ch - AUX_CH_D_XELPD + AUX_CH_D),
                                               encoder->base.name);
        else if (DISPLAY_VER(dev_priv) >= 12 && aux_ch >= AUX_CH_USBC1)
                intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX USBC%c/%s",
                                               aux_ch - AUX_CH_USBC1 + '1',
                                               encoder->base.name);
        else
                intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
                                               aux_ch_name(aux_ch),
                                               encoder->base.name);

        intel_dp->aux.transfer = intel_dp_aux_transfer;
        cpu_latency_qos_add_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
}