/*
 * Copyright 2007-8 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 *
 * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 * Authors: Dave Airlie
 *          Alex Deucher
 *          Jerome Glisse
 */
#include <drm/drmP.h>
#include <drm/radeon_drm.h>
#include "radeon.h"

#include "atom.h"
#include "atom-bits.h"
#include <drm/drm_dp_helper.h>

/* move these to drm_dp_helper.c/h */
#define DP_LINK_CONFIGURATION_SIZE 9
#define DP_DPCD_SIZE DP_RECEIVER_CAP_SIZE

static char *voltage_names[] = {
        "0.4V", "0.6V", "0.8V", "1.2V"
};
static char *pre_emph_names[] = {
        "0dB", "3.5dB", "6dB", "9.5dB"
};

/***** radeon AUX functions *****/

/* Atom needs data in little endian format so swap as appropriate when copying
 * data to or from atom. Note that atom operates on dw units.
 *
 * Use to_le=true when sending data to atom and provide at least
 * ALIGN(num_bytes,4) bytes in the dst buffer.
 *
 * Use to_le=false when receiving data from atom and provide ALIGN(num_bytes,4)
 * byes in the src buffer.
 */
void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le)
{
#ifdef __BIG_ENDIAN
        u32 src_tmp[5], dst_tmp[5];
        int i;
        u8 align_num_bytes = ALIGN(num_bytes, 4);

        if (to_le) {
                memcpy(src_tmp, src, num_bytes);
                for (i = 0; i < align_num_bytes / 4; i++)
                        dst_tmp[i] = cpu_to_le32(src_tmp[i]);
                memcpy(dst, dst_tmp, align_num_bytes);
        } else {
                memcpy(src_tmp, src, align_num_bytes);
                for (i = 0; i < align_num_bytes / 4; i++)
                        dst_tmp[i] = le32_to_cpu(src_tmp[i]);
                memcpy(dst, dst_tmp, num_bytes);
        }
#else
        memcpy(dst, src, num_bytes);
#endif
}

union aux_channel_transaction {
        PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1;
        PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2;
};

static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
                                 u8 *send, int send_bytes,
                                 u8 *recv, int recv_size,
                                 u8 delay, u8 *ack)
{
        struct drm_device *dev = chan->dev;
        struct radeon_device *rdev = dev->dev_private;
        union aux_channel_transaction args;
        int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
        unsigned char *base;
        int recv_bytes;
        int r = 0;

        memset(&args, 0, sizeof(args));

        mutex_lock(&chan->mutex);
        mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);

        base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);

        radeon_atom_copy_swap(base, send, send_bytes, true);

        args.v1.lpAuxRequest = cpu_to_le16((u16)(0 + 4));
        args.v1.lpDataOut = cpu_to_le16((u16)(16 + 4));
        args.v1.ucDataOutLen = 0;
        args.v1.ucChannelID = chan->rec.i2c_id;
        args.v1.ucDelay = delay / 10;
        if (ASIC_IS_DCE4(rdev))
                args.v2.ucHPD_ID = chan->rec.hpd;

        atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);

        *ack = args.v1.ucReplyStatus;

        /* timeout */
        if (args.v1.ucReplyStatus == 1) {
                DRM_DEBUG_KMS("dp_aux_ch timeout\n");
                r = -ETIMEDOUT;
                goto done;
        }

        /* flags not zero */
        if (args.v1.ucReplyStatus == 2) {
                DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
                r = -EIO;
                goto done;
        }

        /* error */
        if (args.v1.ucReplyStatus == 3) {
                DRM_DEBUG_KMS("dp_aux_ch error\n");
                r = -EIO;
                goto done;
        }

        recv_bytes = args.v1.ucDataOutLen;
        if (recv_bytes > recv_size)
                recv_bytes = recv_size;

        if (recv && recv_size)
                radeon_atom_copy_swap(recv, base + 16, recv_bytes, false);

        r = recv_bytes;
done:
        mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
        mutex_unlock(&chan->mutex);

        return r;
}

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

static ssize_t
radeon_dp_aux_transfer_atom(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
{
        struct radeon_i2c_chan *chan =
                container_of(aux, struct radeon_i2c_chan, aux);
        int ret;
        u8 tx_buf[20];
        size_t tx_size;
        u8 ack, delay = 0;

        if (WARN_ON(msg->size > 16))
                return -E2BIG;

        tx_buf[0] = msg->address & 0xff;
        tx_buf[1] = (msg->address >> 8) & 0xff;
        tx_buf[2] = (msg->request << 4) |
                ((msg->address >> 16) & 0xf);
        tx_buf[3] = msg->size ? (msg->size - 1) : 0;

        switch (msg->request & ~DP_AUX_I2C_MOT) {
        case DP_AUX_NATIVE_WRITE:
        case DP_AUX_I2C_WRITE:
        case DP_AUX_I2C_WRITE_STATUS_UPDATE:
                /* The atom implementation only supports writes with a max payload of
                 * 12 bytes since it uses 4 bits for the total count (header + payload)
                 * in the parameter space.  The atom interface supports 16 byte
                 * payloads for reads. The hw itself supports up to 16 bytes of payload.
                 */
                if (WARN_ON_ONCE(msg->size > 12))
                        return -E2BIG;
                /* tx_size needs to be 4 even for bare address packets since the atom
                 * table needs the info in tx_buf[3].
                 */
                tx_size = HEADER_SIZE + msg->size;
                if (msg->size == 0)
                        tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
                else
                        tx_buf[3] |= tx_size << 4;
                memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
                ret = radeon_process_aux_ch(chan,
                                            tx_buf, tx_size, NULL, 0, delay, &ack);
                if (ret >= 0)
                        /* Return payload size. */
                        ret = msg->size;
                break;
        case DP_AUX_NATIVE_READ:
        case DP_AUX_I2C_READ:
                /* tx_size needs to be 4 even for bare address packets since the atom
                 * table needs the info in tx_buf[3].
                 */
                tx_size = HEADER_SIZE;
                if (msg->size == 0)
                        tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
                else
                        tx_buf[3] |= tx_size << 4;
                ret = radeon_process_aux_ch(chan,
                                            tx_buf, tx_size, msg->buffer, msg->size, delay, &ack);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        if (ret >= 0)
                msg->reply = ack >> 4;

        return ret;
}

void radeon_dp_aux_init(struct radeon_connector *radeon_connector)
{
        struct drm_device *dev = radeon_connector->base.dev;
        struct radeon_device *rdev = dev->dev_private;
        int ret;

        radeon_connector->ddc_bus->rec.hpd = radeon_connector->hpd.hpd;
        radeon_connector->ddc_bus->aux.dev = radeon_connector->base.kdev;
        if (ASIC_IS_DCE5(rdev)) {
                if (radeon_auxch)
                        radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_native;
                else
                        radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_atom;
        } else {
                radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_atom;
        }

        ret = drm_dp_aux_register(&radeon_connector->ddc_bus->aux);
        if (!ret)
                radeon_connector->ddc_bus->has_aux = true;

        WARN(ret, "drm_dp_aux_register() failed with error %d\n", ret);
}

/***** general DP utility functions *****/

#define DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_LEVEL_3
#define DP_PRE_EMPHASIS_MAX    DP_TRAIN_PRE_EMPH_LEVEL_3

static void dp_get_adjust_train(const u8 link_status[DP_LINK_STATUS_SIZE],
                                int lane_count,
                                u8 train_set[4])
{
        u8 v = 0;
        u8 p = 0;
        int lane;

        for (lane = 0; lane < lane_count; lane++) {
                u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
                u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);

                DRM_DEBUG_KMS("requested signal parameters: lane %d voltage %s pre_emph %s\n",
                          lane,
                          voltage_names[this_v >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
                          pre_emph_names[this_p >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);

                if (this_v > v)
                        v = this_v;
                if (this_p > p)
                        p = this_p;
        }

        if (v >= DP_VOLTAGE_MAX)
                v |= DP_TRAIN_MAX_SWING_REACHED;

        if (p >= DP_PRE_EMPHASIS_MAX)
                p |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;

        DRM_DEBUG_KMS("using signal parameters: voltage %s pre_emph %s\n",
                  voltage_names[(v & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT],
                  pre_emph_names[(p & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT]);

        for (lane = 0; lane < 4; lane++)
                train_set[lane] = v | p;
}

/* convert bits per color to bits per pixel */
/* get bpc from the EDID */
static int convert_bpc_to_bpp(int bpc)
{
        if (bpc == 0)
                return 24;
        else
                return bpc * 3;
}

/***** radeon specific DP functions *****/

static int radeon_dp_get_dp_link_config(struct drm_connector *connector,
                                        const u8 dpcd[DP_DPCD_SIZE],
                                        unsigned pix_clock,
                                        unsigned *dp_lanes, unsigned *dp_rate)
{
        int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
        static const unsigned link_rates[3] = { 162000, 270000, 540000 };
        unsigned max_link_rate = drm_dp_max_link_rate(dpcd);
        unsigned max_lane_num = drm_dp_max_lane_count(dpcd);
        unsigned lane_num, i, max_pix_clock;

        if (radeon_connector_encoder_get_dp_bridge_encoder_id(connector) ==
            ENCODER_OBJECT_ID_NUTMEG) {
                for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
                        max_pix_clock = (lane_num * 270000 * 8) / bpp;
                        if (max_pix_clock >= pix_clock) {
                                *dp_lanes = lane_num;
                                *dp_rate = 270000;
                                return 0;
                        }
                }
        } else {
                for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
                        for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
                                max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
                                if (max_pix_clock >= pix_clock) {
                                        *dp_lanes = lane_num;
                                        *dp_rate = link_rates[i];
                                        return 0;
                                }
                        }
                }
        }

        return -EINVAL;
}

static u8 radeon_dp_encoder_service(struct radeon_device *rdev,
                                    int action, int dp_clock,
                                    u8 ucconfig, u8 lane_num)
{
        DP_ENCODER_SERVICE_PARAMETERS args;
        int index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);

        memset(&args, 0, sizeof(args));
        args.ucLinkClock = dp_clock / 10;
        args.ucConfig = ucconfig;
        args.ucAction = action;
        args.ucLaneNum = lane_num;
        args.ucStatus = 0;

        atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
        return args.ucStatus;
}

u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector)
{
        struct drm_device *dev = radeon_connector->base.dev;
        struct radeon_device *rdev = dev->dev_private;

        return radeon_dp_encoder_service(rdev, ATOM_DP_ACTION_GET_SINK_TYPE, 0,
                                         radeon_connector->ddc_bus->rec.i2c_id, 0);
}

static void radeon_dp_probe_oui(struct radeon_connector *radeon_connector)
{
        struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
        u8 buf[3];

        if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
                return;

        if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3) == 3)
                DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
                              buf[0], buf[1], buf[2]);

        if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3) == 3)
                DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
                              buf[0], buf[1], buf[2]);
}

bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
{
        struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
        u8 msg[DP_DPCD_SIZE];
        int ret;

        ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_DPCD_REV, msg,
                               DP_DPCD_SIZE);
        if (ret == DP_DPCD_SIZE) {
                memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);

                DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
                              dig_connector->dpcd);

                radeon_dp_probe_oui(radeon_connector);

                return true;
        }

        dig_connector->dpcd[0] = 0;
        return false;
}

int radeon_dp_get_panel_mode(struct drm_encoder *encoder,
                             struct drm_connector *connector)
{
        struct drm_device *dev = encoder->dev;
        struct radeon_device *rdev = dev->dev_private;
        struct radeon_connector *radeon_connector = to_radeon_connector(connector);
        struct radeon_connector_atom_dig *dig_connector;
        int panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
        u16 dp_bridge = radeon_connector_encoder_get_dp_bridge_encoder_id(connector);
        u8 tmp;

        if (!ASIC_IS_DCE4(rdev))
                return panel_mode;

        if (!radeon_connector->con_priv)
                return panel_mode;

        dig_connector = radeon_connector->con_priv;

        if (dp_bridge != ENCODER_OBJECT_ID_NONE) {
                /* DP bridge chips */
                if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux,
                                      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
                        if (tmp & 1)
                                panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
                        else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) ||
                                 (dp_bridge == ENCODER_OBJECT_ID_TRAVIS))
                                panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE;
                        else
                                panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE;
                }
        } else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
                /* eDP */
                if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux,
                                      DP_EDP_CONFIGURATION_CAP, &tmp) == 1) {
                        if (tmp & 1)
                                panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE;
                }
        }

        return panel_mode;
}

void radeon_dp_set_link_config(struct drm_connector *connector,
                               const struct drm_display_mode *mode)
{
        struct radeon_connector *radeon_connector = to_radeon_connector(connector);
        struct radeon_connector_atom_dig *dig_connector;
        int ret;

        if (!radeon_connector->con_priv)
                return;
        dig_connector = radeon_connector->con_priv;

        if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
            (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
                ret = radeon_dp_get_dp_link_config(connector, dig_connector->dpcd,
                                                   mode->clock,
                                                   &dig_connector->dp_lane_count,
                                                   &dig_connector->dp_clock);
                if (ret) {
                        dig_connector->dp_clock = 0;
                        dig_connector->dp_lane_count = 0;
                }
        }
}

int radeon_dp_mode_valid_helper(struct drm_connector *connector,
                                struct drm_display_mode *mode)
{
        struct radeon_connector *radeon_connector = to_radeon_connector(connector);
        struct radeon_connector_atom_dig *dig_connector;
        unsigned dp_clock, dp_lanes;
        int ret;

        if ((mode->clock > 340000) &&
            (!radeon_connector_is_dp12_capable(connector)))
                return MODE_CLOCK_HIGH;

        if (!radeon_connector->con_priv)
                return MODE_CLOCK_HIGH;
        dig_connector = radeon_connector->con_priv;

        ret = radeon_dp_get_dp_link_config(connector, dig_connector->dpcd,
                                           mode->clock,
                                           &dp_lanes,
                                           &dp_clock);
        if (ret)
                return MODE_CLOCK_HIGH;

        if ((dp_clock == 540000) &&
            (!radeon_connector_is_dp12_capable(connector)))
                return MODE_CLOCK_HIGH;

        return MODE_OK;
}

bool radeon_dp_needs_link_train(struct radeon_connector *radeon_connector)
{
        u8 link_status[DP_LINK_STATUS_SIZE];
        struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;

        if (drm_dp_dpcd_read_link_status(&radeon_connector->ddc_bus->aux, link_status)
            <= 0)
                return false;
        if (drm_dp_channel_eq_ok(link_status, dig->dp_lane_count))
                return false;
        return true;
}

void radeon_dp_set_rx_power_state(struct drm_connector *connector,
                                  u8 power_state)
{
        struct radeon_connector *radeon_connector = to_radeon_connector(connector);
        struct radeon_connector_atom_dig *dig_connector;

        if (!radeon_connector->con_priv)
                return;

        dig_connector = radeon_connector->con_priv;

        /* power up/down the sink */
        if (dig_connector->dpcd[0] >= 0x11) {
                drm_dp_dpcd_writeb(&radeon_connector->ddc_bus->aux,
                                   DP_SET_POWER, power_state);
                usleep_range(1000, 2000);
        }
}


struct radeon_dp_link_train_info {
        struct radeon_device *rdev;
        struct drm_encoder *encoder;
        struct drm_connector *connector;
        int enc_id;
        int dp_clock;
        int dp_lane_count;
        bool tp3_supported;
        u8 dpcd[DP_RECEIVER_CAP_SIZE];
        u8 train_set[4];
        u8 link_status[DP_LINK_STATUS_SIZE];
        u8 tries;
        bool use_dpencoder;
        struct drm_dp_aux *aux;
};

static void radeon_dp_update_vs_emph(struct radeon_dp_link_train_info *dp_info)
{
        /* set the initial vs/emph on the source */
        atombios_dig_transmitter_setup(dp_info->encoder,
                                       ATOM_TRANSMITTER_ACTION_SETUP_VSEMPH,
                                       0, dp_info->train_set[0]); /* sets all lanes at once */

        /* set the vs/emph on the sink */
        drm_dp_dpcd_write(dp_info->aux, DP_TRAINING_LANE0_SET,
                          dp_info->train_set, dp_info->dp_lane_count);
}

static void radeon_dp_set_tp(struct radeon_dp_link_train_info *dp_info, int tp)
{
        int rtp = 0;

        /* set training pattern on the source */
        if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder) {
                switch (tp) {
                case DP_TRAINING_PATTERN_1:
                        rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
                        break;
                case DP_TRAINING_PATTERN_2:
                        rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN2;
                        break;
                case DP_TRAINING_PATTERN_3:
                        rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN3;
                        break;
                }
                atombios_dig_encoder_setup(dp_info->encoder, rtp, 0);
        } else {
                switch (tp) {
                case DP_TRAINING_PATTERN_1:
                        rtp = 0;
                        break;
                case DP_TRAINING_PATTERN_2:
                        rtp = 1;
                        break;
                }
                radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_PATTERN_SEL,
                                          dp_info->dp_clock, dp_info->enc_id, rtp);
        }

        /* enable training pattern on the sink */
        drm_dp_dpcd_writeb(dp_info->aux, DP_TRAINING_PATTERN_SET, tp);
}

static int radeon_dp_link_train_init(struct radeon_dp_link_train_info *dp_info)
{
        struct radeon_encoder *radeon_encoder = to_radeon_encoder(dp_info->encoder);
        struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
        u8 tmp;

        /* power up the sink */
        radeon_dp_set_rx_power_state(dp_info->connector, DP_SET_POWER_D0);

        /* possibly enable downspread on the sink */
        if (dp_info->dpcd[3] & 0x1)
                drm_dp_dpcd_writeb(dp_info->aux,
                                   DP_DOWNSPREAD_CTRL, DP_SPREAD_AMP_0_5);
        else
                drm_dp_dpcd_writeb(dp_info->aux,
                                   DP_DOWNSPREAD_CTRL, 0);

        if (dig->panel_mode == DP_PANEL_MODE_INTERNAL_DP2_MODE)
                drm_dp_dpcd_writeb(dp_info->aux, DP_EDP_CONFIGURATION_SET, 1);

        /* set the lane count on the sink */
        tmp = dp_info->dp_lane_count;
        if (drm_dp_enhanced_frame_cap(dp_info->dpcd))
                tmp |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
        drm_dp_dpcd_writeb(dp_info->aux, DP_LANE_COUNT_SET, tmp);

        /* set the link rate on the sink */
        tmp = drm_dp_link_rate_to_bw_code(dp_info->dp_clock);
        drm_dp_dpcd_writeb(dp_info->aux, DP_LINK_BW_SET, tmp);

        /* start training on the source */
        if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
                atombios_dig_encoder_setup(dp_info->encoder,
                                           ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
        else
                radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_START,
                                          dp_info->dp_clock, dp_info->enc_id, 0);

        /* disable the training pattern on the sink */
        drm_dp_dpcd_writeb(dp_info->aux,
                           DP_TRAINING_PATTERN_SET,
                           DP_TRAINING_PATTERN_DISABLE);

        return 0;
}

static int radeon_dp_link_train_finish(struct radeon_dp_link_train_info *dp_info)
{
        udelay(400);

        /* disable the training pattern on the sink */
        drm_dp_dpcd_writeb(dp_info->aux,
                           DP_TRAINING_PATTERN_SET,
                           DP_TRAINING_PATTERN_DISABLE);

        /* disable the training pattern on the source */
        if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
                atombios_dig_encoder_setup(dp_info->encoder,
                                           ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
        else
                radeon_dp_encoder_service(dp_info->rdev, ATOM_DP_ACTION_TRAINING_COMPLETE,
                                          dp_info->dp_clock, dp_info->enc_id, 0);

        return 0;
}

static int radeon_dp_link_train_cr(struct radeon_dp_link_train_info *dp_info)
{
        bool clock_recovery;
        u8 voltage;
        int i;

        radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_1);
        memset(dp_info->train_set, 0, 4);
        radeon_dp_update_vs_emph(dp_info);

        udelay(400);

        /* clock recovery loop */
        clock_recovery = false;
        dp_info->tries = 0;
        voltage = 0xff;
        while (1) {
                drm_dp_link_train_clock_recovery_delay(dp_info->dpcd);

                if (drm_dp_dpcd_read_link_status(dp_info->aux,
                                                 dp_info->link_status) <= 0) {
                        DRM_ERROR("displayport link status failed\n");
                        break;
                }

                if (drm_dp_clock_recovery_ok(dp_info->link_status, dp_info->dp_lane_count)) {
                        clock_recovery = true;
                        break;
                }

                for (i = 0; i < dp_info->dp_lane_count; i++) {
                        if ((dp_info->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
                                break;
                }
                if (i == dp_info->dp_lane_count) {
                        DRM_ERROR("clock recovery reached max voltage\n");
                        break;
                }

                if ((dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
                        ++dp_info->tries;
                        if (dp_info->tries == 5) {
                                DRM_ERROR("clock recovery tried 5 times\n");
                                break;
                        }
                } else
                        dp_info->tries = 0;

                voltage = dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;

                /* Compute new train_set as requested by sink */
                dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);

                radeon_dp_update_vs_emph(dp_info);
        }
        if (!clock_recovery) {
                DRM_ERROR("clock recovery failed\n");
                return -1;
        } else {
                DRM_DEBUG_KMS("clock recovery at voltage %d pre-emphasis %d\n",
                          dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
                          (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK) >>
                          DP_TRAIN_PRE_EMPHASIS_SHIFT);
                return 0;
        }
}

static int radeon_dp_link_train_ce(struct radeon_dp_link_train_info *dp_info)
{
        bool channel_eq;

        if (dp_info->tp3_supported)
                radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_3);
        else
                radeon_dp_set_tp(dp_info, DP_TRAINING_PATTERN_2);

        /* channel equalization loop */
        dp_info->tries = 0;
        channel_eq = false;
        while (1) {
                drm_dp_link_train_channel_eq_delay(dp_info->dpcd);

                if (drm_dp_dpcd_read_link_status(dp_info->aux,
                                                 dp_info->link_status) <= 0) {
                        DRM_ERROR("displayport link status failed\n");
                        break;
                }

                if (drm_dp_channel_eq_ok(dp_info->link_status, dp_info->dp_lane_count)) {
                        channel_eq = true;
                        break;
                }

                /* Try 5 times */
                if (dp_info->tries > 5) {
                        DRM_ERROR("channel eq failed: 5 tries\n");
                        break;
                }

                /* Compute new train_set as requested by sink */
                dp_get_adjust_train(dp_info->link_status, dp_info->dp_lane_count, dp_info->train_set);

                radeon_dp_update_vs_emph(dp_info);
                dp_info->tries++;
        }

        if (!channel_eq) {
                DRM_ERROR("channel eq failed\n");
                return -1;
        } else {
                DRM_DEBUG_KMS("channel eq at voltage %d pre-emphasis %d\n",
                          dp_info->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK,
                          (dp_info->train_set[0] & DP_TRAIN_PRE_EMPHASIS_MASK)
                          >> DP_TRAIN_PRE_EMPHASIS_SHIFT);
                return 0;
        }
}

void radeon_dp_link_train(struct drm_encoder *encoder,
                          struct drm_connector *connector)
{
        struct drm_device *dev = encoder->dev;
        struct radeon_device *rdev = dev->dev_private;
        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
        struct radeon_encoder_atom_dig *dig;
        struct radeon_connector *radeon_connector;
        struct radeon_connector_atom_dig *dig_connector;
        struct radeon_dp_link_train_info dp_info;
        int index;
        u8 tmp, frev, crev;

        if (!radeon_encoder->enc_priv)
                return;
        dig = radeon_encoder->enc_priv;

        radeon_connector = to_radeon_connector(connector);
        if (!radeon_connector->con_priv)
                return;
        dig_connector = radeon_connector->con_priv;

        if ((dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_DISPLAYPORT) &&
            (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
                return;

        /* DPEncoderService newer than 1.1 can't program properly the
         * training pattern. When facing such version use the
         * DIGXEncoderControl (X== 1 | 2)
         */
        dp_info.use_dpencoder = true;
        index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
        if (atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev)) {
                if (crev > 1) {
                        dp_info.use_dpencoder = false;
                }
        }

        dp_info.enc_id = 0;
        if (dig->dig_encoder)
                dp_info.enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER;
        else
                dp_info.enc_id |= ATOM_DP_CONFIG_DIG1_ENCODER;
        if (dig->linkb)
                dp_info.enc_id |= ATOM_DP_CONFIG_LINK_B;
        else
                dp_info.enc_id |= ATOM_DP_CONFIG_LINK_A;

        if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp)
            == 1) {
                if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED))
                        dp_info.tp3_supported = true;
                else
                        dp_info.tp3_supported = false;
        } else {
                dp_info.tp3_supported = false;
        }

        memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
        dp_info.rdev = rdev;
        dp_info.encoder = encoder;
        dp_info.connector = connector;
        dp_info.dp_lane_count = dig_connector->dp_lane_count;
        dp_info.dp_clock = dig_connector->dp_clock;
        dp_info.aux = &radeon_connector->ddc_bus->aux;

        if (radeon_dp_link_train_init(&dp_info))
                goto done;
        if (radeon_dp_link_train_cr(&dp_info))
                goto done;
        if (radeon_dp_link_train_ce(&dp_info))
                goto done;
done:
        if (radeon_dp_link_train_finish(&dp_info))
                return;
}