/*
 * Copyright 2009 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: Ben Skeggs
 */

#include "drmP.h"
#include "nouveau_drv.h"
#include "nouveau_i2c.h"
#include "nouveau_encoder.h"

static int
auxch_rd(struct drm_encoder *encoder, int address, uint8_t *buf, int size)
{
	struct drm_device *dev = encoder->dev;
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct nouveau_i2c_chan *auxch;
	int ret;

	auxch = nouveau_i2c_find(dev, nv_encoder->dcb->i2c_index);
	if (!auxch)
		return -ENODEV;

	ret = nouveau_dp_auxch(auxch, 9, address, buf, size);
	if (ret)
		return ret;

	return 0;
}

static int
auxch_wr(struct drm_encoder *encoder, int address, uint8_t *buf, int size)
{
	struct drm_device *dev = encoder->dev;
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct nouveau_i2c_chan *auxch;
	int ret;

	auxch = nouveau_i2c_find(dev, nv_encoder->dcb->i2c_index);
	if (!auxch)
		return -ENODEV;

	ret = nouveau_dp_auxch(auxch, 8, address, buf, size);
	return ret;
}

static int
nouveau_dp_lane_count_set(struct drm_encoder *encoder, uint8_t cmd)
{
	struct drm_device *dev = encoder->dev;
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	uint32_t tmp;
	int or = nv_encoder->or, link = !(nv_encoder->dcb->sorconf.link & 1);

	tmp  = nv_rd32(dev, NV50_SOR_DP_CTRL(or, link));
	tmp &= ~(NV50_SOR_DP_CTRL_ENHANCED_FRAME_ENABLED |
		 NV50_SOR_DP_CTRL_LANE_MASK);
	tmp |= ((1 << (cmd & DP_LANE_COUNT_MASK)) - 1) << 16;
	if (cmd & DP_LANE_COUNT_ENHANCED_FRAME_EN)
		tmp |= NV50_SOR_DP_CTRL_ENHANCED_FRAME_ENABLED;
	nv_wr32(dev, NV50_SOR_DP_CTRL(or, link), tmp);

	return auxch_wr(encoder, DP_LANE_COUNT_SET, &cmd, 1);
}

static int
nouveau_dp_link_bw_set(struct drm_encoder *encoder, uint8_t cmd)
{
	struct drm_device *dev = encoder->dev;
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	uint32_t tmp;
	int reg = 0x614300 + (nv_encoder->or * 0x800);

	tmp  = nv_rd32(dev, reg);
	tmp &= 0xfff3ffff;
	if (cmd == DP_LINK_BW_2_7)
		tmp |= 0x00040000;
	nv_wr32(dev, reg, tmp);

	return auxch_wr(encoder, DP_LINK_BW_SET, &cmd, 1);
}

static int
nouveau_dp_link_train_set(struct drm_encoder *encoder, int pattern)
{
	struct drm_device *dev = encoder->dev;
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	uint32_t tmp;
	uint8_t cmd;
	int or = nv_encoder->or, link = !(nv_encoder->dcb->sorconf.link & 1);
	int ret;

	tmp  = nv_rd32(dev, NV50_SOR_DP_CTRL(or, link));
	tmp &= ~NV50_SOR_DP_CTRL_TRAINING_PATTERN;
	tmp |= (pattern << 24);
	nv_wr32(dev, NV50_SOR_DP_CTRL(or, link), tmp);

	ret = auxch_rd(encoder, DP_TRAINING_PATTERN_SET, &cmd, 1);
	if (ret)
		return ret;
	cmd &= ~DP_TRAINING_PATTERN_MASK;
	cmd |= (pattern & DP_TRAINING_PATTERN_MASK);
	return auxch_wr(encoder, DP_TRAINING_PATTERN_SET, &cmd, 1);
}

static int
nouveau_dp_max_voltage_swing(struct drm_encoder *encoder)
{
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct drm_device *dev = encoder->dev;
	struct bit_displayport_encoder_table_entry *dpse;
	struct bit_displayport_encoder_table *dpe;
	int i, dpe_headerlen, max_vs = 0;

	dpe = nouveau_bios_dp_table(dev, nv_encoder->dcb, &dpe_headerlen);
	if (!dpe)
		return false;
	dpse = (void *)((char *)dpe + dpe_headerlen);

	for (i = 0; i < dpe_headerlen; i++, dpse++) {
		if (dpse->vs_level > max_vs)
			max_vs = dpse->vs_level;
	}

	return max_vs;
}

static int
nouveau_dp_max_pre_emphasis(struct drm_encoder *encoder, int vs)
{
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct drm_device *dev = encoder->dev;
	struct bit_displayport_encoder_table_entry *dpse;
	struct bit_displayport_encoder_table *dpe;
	int i, dpe_headerlen, max_pre = 0;

	dpe = nouveau_bios_dp_table(dev, nv_encoder->dcb, &dpe_headerlen);
	if (!dpe)
		return false;
	dpse = (void *)((char *)dpe + dpe_headerlen);

	for (i = 0; i < dpe_headerlen; i++, dpse++) {
		if (dpse->vs_level != vs)
			continue;

		if (dpse->pre_level > max_pre)
			max_pre = dpse->pre_level;
	}

	return max_pre;
}

static bool
nouveau_dp_link_train_adjust(struct drm_encoder *encoder, uint8_t *config)
{
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct drm_device *dev = encoder->dev;
	struct bit_displayport_encoder_table_entry *dpse;
	struct bit_displayport_encoder_table *dpe;
	int ret, i, dpe_headerlen, vs = 0, pre = 0;
	uint8_t request[2];

	dpe = nouveau_bios_dp_table(dev, nv_encoder->dcb, &dpe_headerlen);
	if (!dpe)
		return false;
	dpse = (void *)((char *)dpe + dpe_headerlen);

	ret = auxch_rd(encoder, DP_ADJUST_REQUEST_LANE0_1, request, 2);
	if (ret)
		return false;

	NV_DEBUG_KMS(dev, "\t\tadjust 0x%02x 0x%02x\n", request[0], request[1]);

	/* Keep all lanes at the same level.. */
	for (i = 0; i < nv_encoder->dp.link_nr; i++) {
		int lane_req = (request[i >> 1] >> ((i & 1) << 2)) & 0xf;
		int lane_vs = lane_req & 3;
		int lane_pre = (lane_req >> 2) & 3;

		if (lane_vs > vs)
			vs = lane_vs;
		if (lane_pre > pre)
			pre = lane_pre;
	}

	if (vs >= nouveau_dp_max_voltage_swing(encoder)) {
		vs  = nouveau_dp_max_voltage_swing(encoder);
		vs |= 4;
	}

	if (pre >= nouveau_dp_max_pre_emphasis(encoder, vs & 3)) {
		pre  = nouveau_dp_max_pre_emphasis(encoder, vs & 3);
		pre |= 4;
	}

	/* Update the configuration for all lanes.. */
	for (i = 0; i < nv_encoder->dp.link_nr; i++)
		config[i] = (pre << 3) | vs;

	return true;
}

static bool
nouveau_dp_link_train_commit(struct drm_encoder *encoder, uint8_t *config)
{
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct drm_device *dev = encoder->dev;
	struct bit_displayport_encoder_table_entry *dpse;
	struct bit_displayport_encoder_table *dpe;
	int or = nv_encoder->or, link = !(nv_encoder->dcb->sorconf.link & 1);
	int dpe_headerlen, ret, i;

	NV_DEBUG_KMS(dev, "\t\tconfig 0x%02x 0x%02x 0x%02x 0x%02x\n",
		 config[0], config[1], config[2], config[3]);

	dpe = nouveau_bios_dp_table(dev, nv_encoder->dcb, &dpe_headerlen);
	if (!dpe)
		return false;
	dpse = (void *)((char *)dpe + dpe_headerlen);

	for (i = 0; i < dpe->record_nr; i++, dpse++) {
		if (dpse->vs_level == (config[0] & 3) &&
		    dpse->pre_level == ((config[0] >> 3) & 3))
			break;
	}
	BUG_ON(i == dpe->record_nr);

	for (i = 0; i < nv_encoder->dp.link_nr; i++) {
		const int shift[4] = { 16, 8, 0, 24 };
		uint32_t mask = 0xff << shift[i];
		uint32_t reg0, reg1, reg2;

		reg0  = nv_rd32(dev, NV50_SOR_DP_UNK118(or, link)) & ~mask;
		reg0 |= (dpse->reg0 << shift[i]);
		reg1  = nv_rd32(dev, NV50_SOR_DP_UNK120(or, link)) & ~mask;
		reg1 |= (dpse->reg1 << shift[i]);
		reg2  = nv_rd32(dev, NV50_SOR_DP_UNK130(or, link)) & 0xffff00ff;
		reg2 |= (dpse->reg2 << 8);
		nv_wr32(dev, NV50_SOR_DP_UNK118(or, link), reg0);
		nv_wr32(dev, NV50_SOR_DP_UNK120(or, link), reg1);
		nv_wr32(dev, NV50_SOR_DP_UNK130(or, link), reg2);
	}

	ret = auxch_wr(encoder, DP_TRAINING_LANE0_SET, config, 4);
	if (ret)
		return false;

	return true;
}

bool
nouveau_dp_link_train(struct drm_encoder *encoder)
{
	struct drm_device *dev = encoder->dev;
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	uint8_t config[4];
	uint8_t status[3];
	bool cr_done, cr_max_vs, eq_done;
	int ret = 0, i, tries, voltage;

	NV_DEBUG_KMS(dev, "link training!!\n");
train:
	cr_done = eq_done = false;

	/* set link configuration */
	NV_DEBUG_KMS(dev, "\tbegin train: bw %d, lanes %d\n",
		 nv_encoder->dp.link_bw, nv_encoder->dp.link_nr);

	ret = nouveau_dp_link_bw_set(encoder, nv_encoder->dp.link_bw);
	if (ret)
		return false;

	config[0] = nv_encoder->dp.link_nr;
	if (nv_encoder->dp.dpcd_version >= 0x11)
		config[0] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;

	ret = nouveau_dp_lane_count_set(encoder, config[0]);
	if (ret)
		return false;

	/* clock recovery */
	NV_DEBUG_KMS(dev, "\tbegin cr\n");
	ret = nouveau_dp_link_train_set(encoder, DP_TRAINING_PATTERN_1);
	if (ret)
		goto stop;

	tries = 0;
	voltage = -1;
	memset(config, 0x00, sizeof(config));
	for (;;) {
		if (!nouveau_dp_link_train_commit(encoder, config))
			break;

		udelay(100);

		ret = auxch_rd(encoder, DP_LANE0_1_STATUS, status, 2);
		if (ret)
			break;
		NV_DEBUG_KMS(dev, "\t\tstatus: 0x%02x 0x%02x\n",
			 status[0], status[1]);

		cr_done = true;
		cr_max_vs = false;
		for (i = 0; i < nv_encoder->dp.link_nr; i++) {
			int lane = (status[i >> 1] >> ((i & 1) * 4)) & 0xf;

			if (!(lane & DP_LANE_CR_DONE)) {
				cr_done = false;
				if (config[i] & DP_TRAIN_MAX_PRE_EMPHASIS_REACHED)
					cr_max_vs = true;
				break;
			}
		}

		if ((config[0] & DP_TRAIN_VOLTAGE_SWING_MASK) != voltage) {
			voltage = config[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
			tries = 0;
		}

		if (cr_done || cr_max_vs || (++tries == 5))
			break;

		if (!nouveau_dp_link_train_adjust(encoder, config))
			break;
	}

	if (!cr_done)
		goto stop;

	/* channel equalisation */
	NV_DEBUG_KMS(dev, "\tbegin eq\n");
	ret = nouveau_dp_link_train_set(encoder, DP_TRAINING_PATTERN_2);
	if (ret)
		goto stop;

	for (tries = 0; tries <= 5; tries++) {
		udelay(400);

		ret = auxch_rd(encoder, DP_LANE0_1_STATUS, status, 3);
		if (ret)
			break;
		NV_DEBUG_KMS(dev, "\t\tstatus: 0x%02x 0x%02x\n",
			 status[0], status[1]);

		eq_done = true;
		if (!(status[2] & DP_INTERLANE_ALIGN_DONE))
			eq_done = false;

		for (i = 0; eq_done && i < nv_encoder->dp.link_nr; i++) {
			int lane = (status[i >> 1] >> ((i & 1) * 4)) & 0xf;

			if (!(lane & DP_LANE_CR_DONE)) {
				cr_done = false;
				break;
			}

			if (!(lane & DP_LANE_CHANNEL_EQ_DONE) ||
			    !(lane & DP_LANE_SYMBOL_LOCKED)) {
				eq_done = false;
				break;
			}
		}

		if (eq_done || !cr_done)
			break;

		if (!nouveau_dp_link_train_adjust(encoder, config) ||
		    !nouveau_dp_link_train_commit(encoder, config))
			break;
	}

stop:
	/* end link training */
	ret = nouveau_dp_link_train_set(encoder, DP_TRAINING_PATTERN_DISABLE);
	if (ret)
		return false;

	/* retry at a lower setting, if possible */
	if (!ret && !(eq_done && cr_done)) {
		NV_DEBUG_KMS(dev, "\twe failed\n");
		if (nv_encoder->dp.link_bw != DP_LINK_BW_1_62) {
			NV_DEBUG_KMS(dev, "retry link training at low rate\n");
			nv_encoder->dp.link_bw = DP_LINK_BW_1_62;
			goto train;
		}
	}

	return eq_done;
}

bool
nouveau_dp_detect(struct drm_encoder *encoder)
{
	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
	struct drm_device *dev = encoder->dev;
	uint8_t dpcd[4];
	int ret;

	ret = auxch_rd(encoder, 0x0000, dpcd, 4);
	if (ret)
		return false;

	NV_DEBUG_KMS(dev, "encoder: link_bw %d, link_nr %d\n"
		      "display: link_bw %d, link_nr %d version 0x%02x\n",
		 nv_encoder->dcb->dpconf.link_bw,
		 nv_encoder->dcb->dpconf.link_nr,
		 dpcd[1], dpcd[2] & 0x0f, dpcd[0]);

	nv_encoder->dp.dpcd_version = dpcd[0];

	nv_encoder->dp.link_bw = dpcd[1];
	if (nv_encoder->dp.link_bw != DP_LINK_BW_1_62 &&
	    !nv_encoder->dcb->dpconf.link_bw)
		nv_encoder->dp.link_bw = DP_LINK_BW_1_62;

	nv_encoder->dp.link_nr = dpcd[2] & 0xf;
	if (nv_encoder->dp.link_nr > nv_encoder->dcb->dpconf.link_nr)
		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;

	return true;
}

int
nouveau_dp_auxch(struct nouveau_i2c_chan *auxch, int cmd, int addr,
		 uint8_t *data, int data_nr)
{
	struct drm_device *dev = auxch->dev;
	uint32_t tmp, ctrl, stat = 0, data32[4] = {};
	int ret = 0, i, index = auxch->rd;

	NV_DEBUG_KMS(dev, "ch %d cmd %d addr 0x%x len %d\n", index, cmd, addr, data_nr);

	tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
	nv_wr32(dev, NV50_AUXCH_CTRL(auxch->rd), tmp | 0x00100000);
	tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
	if (!(tmp & 0x01000000)) {
		NV_ERROR(dev, "expected bit 24 == 1, got 0x%08x\n", tmp);
		ret = -EIO;
		goto out;
	}

	for (i = 0; i < 3; i++) {
		tmp = nv_rd32(dev, NV50_AUXCH_STAT(auxch->rd));
		if (tmp & NV50_AUXCH_STAT_STATE_READY)
			break;
		udelay(100);
	}

	if (i == 3) {
		ret = -EBUSY;
		goto out;
	}

	if (!(cmd & 1)) {
		memcpy(data32, data, data_nr);
		for (i = 0; i < 4; i++) {
			NV_DEBUG_KMS(dev, "wr %d: 0x%08x\n", i, data32[i]);
			nv_wr32(dev, NV50_AUXCH_DATA_OUT(index, i), data32[i]);
		}
	}

	nv_wr32(dev, NV50_AUXCH_ADDR(index), addr);
	ctrl  = nv_rd32(dev, NV50_AUXCH_CTRL(index));
	ctrl &= ~(NV50_AUXCH_CTRL_CMD | NV50_AUXCH_CTRL_LEN);
	ctrl |= (cmd << NV50_AUXCH_CTRL_CMD_SHIFT);
	ctrl |= ((data_nr - 1) << NV50_AUXCH_CTRL_LEN_SHIFT);

	for (i = 0; i < 16; i++) {
		nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl | 0x80000000);
		nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl);
		nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl | 0x00010000);
		if (!nv_wait(NV50_AUXCH_CTRL(index), 0x00010000, 0x00000000)) {
			NV_ERROR(dev, "expected bit 16 == 0, got 0x%08x\n",
				 nv_rd32(dev, NV50_AUXCH_CTRL(index)));
			ret = -EBUSY;
			goto out;
		}

		udelay(400);

		stat = nv_rd32(dev, NV50_AUXCH_STAT(index));
		if ((stat & NV50_AUXCH_STAT_REPLY_AUX) !=
			    NV50_AUXCH_STAT_REPLY_AUX_DEFER)
			break;
	}

	if (i == 16) {
		NV_ERROR(dev, "auxch DEFER too many times, bailing\n");
		ret = -EREMOTEIO;
		goto out;
	}

	if (cmd & 1) {
		if ((stat & NV50_AUXCH_STAT_COUNT) != data_nr) {
			ret = -EREMOTEIO;
			goto out;
		}

		for (i = 0; i < 4; i++) {
			data32[i] = nv_rd32(dev, NV50_AUXCH_DATA_IN(index, i));
			NV_DEBUG_KMS(dev, "rd %d: 0x%08x\n", i, data32[i]);
		}
		memcpy(data, data32, data_nr);
	}

out:
	tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
	nv_wr32(dev, NV50_AUXCH_CTRL(auxch->rd), tmp & ~0x00100000);
	tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
	if (tmp & 0x01000000) {
		NV_ERROR(dev, "expected bit 24 == 0, got 0x%08x\n", tmp);
		ret = -EIO;
	}

	udelay(400);

	return ret ? ret : (stat & NV50_AUXCH_STAT_REPLY);
}

int
nouveau_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
		      uint8_t write_byte, uint8_t *read_byte)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	struct nouveau_i2c_chan *auxch = (struct nouveau_i2c_chan *)adapter;
	struct drm_device *dev = auxch->dev;
	int ret = 0, cmd, addr = algo_data->address;
	uint8_t *buf;

	if (mode == MODE_I2C_READ) {
		cmd = AUX_I2C_READ;
		buf = read_byte;
	} else {
		cmd = (mode & MODE_I2C_READ) ? AUX_I2C_READ : AUX_I2C_WRITE;
		buf = &write_byte;
	}

	if (!(mode & MODE_I2C_STOP))
		cmd |= AUX_I2C_MOT;

	if (mode & MODE_I2C_START)
		return 1;

	for (;;) {
		ret = nouveau_dp_auxch(auxch, cmd, addr, buf, 1);
		if (ret < 0)
			return ret;

		switch (ret & NV50_AUXCH_STAT_REPLY_I2C) {
		case NV50_AUXCH_STAT_REPLY_I2C_ACK:
			return 1;
		case NV50_AUXCH_STAT_REPLY_I2C_NACK:
			return -EREMOTEIO;
		case NV50_AUXCH_STAT_REPLY_I2C_DEFER:
			udelay(100);
			break;
		default:
			NV_ERROR(dev, "invalid auxch status: 0x%08x\n", ret);
			return -EREMOTEIO;
		}
	}
}