ite-it66121.c

	switch (audio_swl) {
	case 16:
		audio_enable |= IT66121_AUD_16BIT;
		break;
	case 18:
		audio_enable |= IT66121_AUD_18BIT;
		break;
	case 20:
		audio_enable |= IT66121_AUD_20BIT;
		break;
	case 24:
	default:
		audio_enable |= IT66121_AUD_24BIT;
		break;
	}

	audio_format |= 0x40;
	switch (audio_src_num) {
	case 4:
		audio_enable |= IT66121_AUD_EN_I2S3 | IT66121_AUD_EN_I2S2 |
				IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0;
		break;
	case 3:
		audio_enable |= IT66121_AUD_EN_I2S2 | IT66121_AUD_EN_I2S1 |
				IT66121_AUD_EN_I2S0;
		break;
	case 2:
		audio_enable |= IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0;
		break;
	case 1:
	default:
		audio_format &= ~0x40;
		audio_enable |= IT66121_AUD_EN_I2S0;
		break;
	}

	audio_format |= 0x01;
	ctx->audio.ch_enable = audio_enable;

	ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL0_REG, audio_enable & 0xF0);
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL1_REG, audio_format);
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, IT66121_AUD_FIFOMAP_REG, 0xE4);
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL3_REG, 0x00);
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG, 0x00);
	if (ret)
		return ret;

	return regmap_write(ctx->regmap, IT66121_AUD_HDAUDIO_REG, 0x00);
}

static int it661221_set_ncts(struct it66121_ctx *ctx, u8 fs)
{
	int ret;
	unsigned int n;

	switch (fs) {
	case IT66121_AUD_FS_32K:
		n = 4096;
		break;
	case IT66121_AUD_FS_44P1K:
		n = 6272;
		break;
	case IT66121_AUD_FS_48K:
		n = 6144;
		break;
	case IT66121_AUD_FS_88P2K:
		n = 12544;
		break;
	case IT66121_AUD_FS_96K:
		n = 12288;
		break;
	case IT66121_AUD_FS_176P4K:
		n = 25088;
		break;
	case IT66121_AUD_FS_192K:
		n = 24576;
		break;
	case IT66121_AUD_FS_768K:
		n = 24576;
		break;
	default:
		n = 6144;
		break;
	}

	ret = regmap_write(ctx->regmap, IT66121_AUD_PKT_N0_REG, (u8)((n) & 0xFF));
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, IT66121_AUD_PKT_N1_REG, (u8)((n >> 8) & 0xFF));
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, IT66121_AUD_PKT_N2_REG, (u8)((n >> 16) & 0xF));
	if (ret)
		return ret;

	if (ctx->audio.auto_cts) {
		u8 loop_cnt = 255;
		u8 cts_stable_cnt = 0;
		unsigned int sum_cts = 0;
		unsigned int cts = 0;
		unsigned int last_cts = 0;
		unsigned int diff;
		unsigned int val;

		while (loop_cnt--) {
			msleep(30);
			regmap_read(ctx->regmap, IT66121_AUD_PKT_CTS_CNT2_REG, &val);
			cts = val << 12;
			regmap_read(ctx->regmap, IT66121_AUD_PKT_CTS_CNT1_REG, &val);
			cts |= val << 4;
			regmap_read(ctx->regmap, IT66121_AUD_PKT_CTS_CNT0_REG, &val);
			cts |= val >> 4;
			if (cts == 0) {
				continue;
			} else {
				if (last_cts > cts)
					diff = last_cts - cts;
				else
					diff = cts - last_cts;
				last_cts = cts;
				if (diff < 5) {
					cts_stable_cnt++;
					sum_cts += cts;
				} else {
					cts_stable_cnt = 0;
					sum_cts = 0;
					continue;
				}

				if (cts_stable_cnt >= 32) {
					last_cts = (sum_cts >> 5);
					break;
				}
			}
		}

		regmap_write(ctx->regmap, IT66121_AUD_PKT_CTS0_REG, (u8)((last_cts) & 0xFF));
		regmap_write(ctx->regmap, IT66121_AUD_PKT_CTS1_REG, (u8)((last_cts >> 8) & 0xFF));
		regmap_write(ctx->regmap, IT66121_AUD_PKT_CTS2_REG, (u8)((last_cts >> 16) & 0x0F));
	}

	ret = regmap_write(ctx->regmap, 0xF8, 0xC3);
	if (ret)
		return ret;

	ret = regmap_write(ctx->regmap, 0xF8, 0xA5);
	if (ret)
		return ret;

	if (ctx->audio.auto_cts) {
		ret = regmap_write_bits(ctx->regmap, IT66121_PKT_CTS_CTRL_REG,
					IT66121_PKT_CTS_CTRL_SEL,
					1);
	} else {
		ret = regmap_write_bits(ctx->regmap, IT66121_PKT_CTS_CTRL_REG,
					IT66121_PKT_CTS_CTRL_SEL,
					0);
	}

	if (ret)
		return ret;

	return regmap_write(ctx->regmap, 0xF8, 0xFF);
}

static int it661221_audio_output_enable(struct it66121_ctx *ctx, bool enable)
{
	int ret;

	if (enable) {
		ret = regmap_write_bits(ctx->regmap, IT66121_SW_RST_REG,
					IT66121_SW_RST_AUD | IT66121_SW_RST_AREF,
					0);
		if (ret)
			return ret;

		ret = regmap_write_bits(ctx->regmap, IT66121_AUD_CTRL0_REG,
					IT66121_AUD_EN_I2S3 | IT66121_AUD_EN_I2S2 |
					IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0,
					ctx->audio.ch_enable);
	} else {
		ret = regmap_write_bits(ctx->regmap, IT66121_AUD_CTRL0_REG,
					IT66121_AUD_EN_I2S3 | IT66121_AUD_EN_I2S2 |
					IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0,
					ctx->audio.ch_enable & 0xF0);
		if (ret)
			return ret;

		ret = regmap_write_bits(ctx->regmap, IT66121_SW_RST_REG,
					IT66121_SW_RST_AUD | IT66121_SW_RST_AREF,
					IT66121_SW_RST_AUD | IT66121_SW_RST_AREF);
	}

	return ret;
}

static int it661221_audio_ch_enable(struct it66121_ctx *ctx, bool enable)
{
	int ret;

	if (enable) {
		ret = regmap_write(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG, 0);
		if (ret)
			return ret;

		ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL0_REG, ctx->audio.ch_enable);
	} else {
		ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL0_REG, ctx->audio.ch_enable & 0xF0);
	}

	return ret;
}

static int it66121_audio_hw_params(struct device *dev, void *data,
				   struct hdmi_codec_daifmt *daifmt,
				   struct hdmi_codec_params *params)
{
	u8 fs;
	u8 swl;
	int ret;
	struct it66121_ctx *ctx = dev_get_drvdata(dev);
	static u8 iec60958_chstat[5];
	unsigned int channels = params->channels;
	unsigned int sample_rate = params->sample_rate;
	unsigned int sample_width = params->sample_width;

	mutex_lock(&ctx->lock);
	dev_dbg(dev, "%s: %u, %u, %u, %u\n", __func__,
		daifmt->fmt, sample_rate, sample_width, channels);

	switch (daifmt->fmt) {
	case HDMI_I2S:
		dev_dbg(dev, "Using HDMI I2S\n");
		break;
	default:
		dev_err(dev, "Invalid or unsupported DAI format %d\n", daifmt->fmt);
		ret = -EINVAL;
		goto out;
	}

	// Set audio clock recovery (N/CTS)
	ret = regmap_write(ctx->regmap, IT66121_CLK_CTRL0_REG,
			   IT66121_CLK_CTRL0_AUTO_OVER_SAMPLING |
			   IT66121_CLK_CTRL0_EXT_MCLK_256FS |
			   IT66121_CLK_CTRL0_AUTO_IPCLK);
	if (ret)
		goto out;

	ret = regmap_write_bits(ctx->regmap, IT66121_AUD_CTRL0_REG,
				IT66121_AUD_CTRL0_AUD_SEL, 0); // remove spdif selection
	if (ret)
		goto out;

	switch (sample_rate) {
	case 44100L:
		fs = IT66121_AUD_FS_44P1K;
		break;
	case 88200L:
		fs = IT66121_AUD_FS_88P2K;
		break;
	case 176400L:
		fs = IT66121_AUD_FS_176P4K;
		break;
	case 32000L:
		fs = IT66121_AUD_FS_32K;
		break;
	case 48000L:
		fs = IT66121_AUD_FS_48K;
		break;
	case 96000L:
		fs = IT66121_AUD_FS_96K;
		break;
	case 192000L:
		fs = IT66121_AUD_FS_192K;
		break;
	case 768000L:
		fs = IT66121_AUD_FS_768K;
		break;
	default:
		fs = IT66121_AUD_FS_48K;
		break;
	}

	ctx->audio.fs = fs;
	ret = it661221_set_ncts(ctx, fs);
	if (ret) {
		dev_err(dev, "Failed to set N/CTS: %d\n", ret);
		goto out;
	}

	// Set audio format register (except audio channel enable)
	ret = it661221_set_lpcm_audio(ctx, (channels + 1) / 2, sample_width);
	if (ret) {
		dev_err(dev, "Failed to set LPCM audio: %d\n", ret);
		goto out;
	}

	// Set audio channel status
	iec60958_chstat[0] = 0;
	if ((channels + 1) / 2 == 1)
		iec60958_chstat[0] |= 0x1;
	iec60958_chstat[0] &= ~(1 << 1);
	iec60958_chstat[1] = 0;
	iec60958_chstat[2] = (channels + 1) / 2;
	iec60958_chstat[2] |= (channels << 4) & 0xF0;
	iec60958_chstat[3] = fs;

	switch (sample_width) {
	case 21L:
		swl = IT66121_AUD_SWL_21BIT;
		break;
	case 24L:
		swl = IT66121_AUD_SWL_24BIT;
		break;
	case 23L:
		swl = IT66121_AUD_SWL_23BIT;
		break;
	case 22L:
		swl = IT66121_AUD_SWL_22BIT;
		break;
	case 20L:
		swl = IT66121_AUD_SWL_20BIT;
		break;
	case 17L:
		swl = IT66121_AUD_SWL_17BIT;
		break;
	case 19L:
		swl = IT66121_AUD_SWL_19BIT;
		break;
	case 18L:
		swl = IT66121_AUD_SWL_18BIT;
		break;
	case 16L:
		swl = IT66121_AUD_SWL_16BIT;
		break;
	default:
		swl = IT66121_AUD_SWL_NOT_INDICATED;
		break;
	}

	iec60958_chstat[4] = (((~fs) << 4) & 0xF0) | swl;
	ret = it661221_set_chstat(ctx, iec60958_chstat);
	if (ret) {
		dev_err(dev, "Failed to set channel status: %d\n", ret);
		goto out;
	}

	// Enable audio channel enable while input clock stable (if SPDIF).
	ret = it661221_audio_ch_enable(ctx, true);
	if (ret) {
		dev_err(dev, "Failed to enable audio channel: %d\n", ret);
		goto out;
	}

	ret = regmap_write_bits(ctx->regmap, IT66121_INT_MASK1_REG,
				IT66121_INT_MASK1_AUD_OVF,
				0);
	if (ret)
		goto out;

	dev_dbg(dev, "HDMI audio enabled.\n");
out:
	mutex_unlock(&ctx->lock);

	return ret;
}

static int it66121_audio_startup(struct device *dev, void *data)
{
	int ret;
	struct it66121_ctx *ctx = dev_get_drvdata(dev);

	dev_dbg(dev, "%s\n", __func__);

	mutex_lock(&ctx->lock);
	ret = it661221_audio_output_enable(ctx, true);
	if (ret)
		dev_err(dev, "Failed to enable audio output: %d\n", ret);

	mutex_unlock(&ctx->lock);

	return ret;
}

static void it66121_audio_shutdown(struct device *dev, void *data)
{
	int ret;
	struct it66121_ctx *ctx = dev_get_drvdata(dev);

	dev_dbg(dev, "%s\n", __func__);

	mutex_lock(&ctx->lock);
	ret = it661221_audio_output_enable(ctx, false);
	if (ret)
		dev_err(dev, "Failed to disable audio output: %d\n", ret);

	mutex_unlock(&ctx->lock);
}

static int it66121_audio_mute(struct device *dev, void *data,
			      bool enable, int direction)
{
	int ret;
	struct it66121_ctx *ctx = dev_get_drvdata(dev);

	dev_dbg(dev, "%s: enable=%s, direction=%d\n",
		__func__, enable ? "true" : "false", direction);

	mutex_lock(&ctx->lock);

	if (enable) {
		ret = regmap_write_bits(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG,
					IT66121_AUD_FLAT_SRC0 | IT66121_AUD_FLAT_SRC1 |
					IT66121_AUD_FLAT_SRC2 | IT66121_AUD_FLAT_SRC3,
					IT66121_AUD_FLAT_SRC0 | IT66121_AUD_FLAT_SRC1 |
					IT66121_AUD_FLAT_SRC2 | IT66121_AUD_FLAT_SRC3);
	} else {
		ret = regmap_write_bits(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG,
					IT66121_AUD_FLAT_SRC0 | IT66121_AUD_FLAT_SRC1 |
					IT66121_AUD_FLAT_SRC2 | IT66121_AUD_FLAT_SRC3,
					0);
	}

	mutex_unlock(&ctx->lock);

	return ret;
}

static int it66121_audio_get_eld(struct device *dev, void *data,
				 u8 *buf, size_t len)
{
	struct it66121_ctx *ctx = dev_get_drvdata(dev);

	mutex_lock(&ctx->lock);
	if (!ctx->connector) {
		/* Pass en empty ELD if connector not available */
		dev_dbg(dev, "No connector present, passing empty EDID data");
		memset(buf, 0, len);
	} else {
		memcpy(buf, ctx->connector->eld,
		       min(sizeof(ctx->connector->eld), len));
	}
	mutex_unlock(&ctx->lock);

	return 0;
}

static const struct hdmi_codec_ops it66121_audio_codec_ops = {
	.hw_params = it66121_audio_hw_params,
	.audio_startup = it66121_audio_startup,
	.audio_shutdown = it66121_audio_shutdown,
	.mute_stream = it66121_audio_mute,
	.get_eld = it66121_audio_get_eld,
	.no_capture_mute = 1,
};

static int it66121_audio_codec_init(struct it66121_ctx *ctx, struct device *dev)
{
	struct hdmi_codec_pdata codec_data = {
		.ops = &it66121_audio_codec_ops,
		.i2s = 1, /* Only i2s support for now */
		.spdif = 0,
		.max_i2s_channels = 8,
	};

	dev_dbg(dev, "%s\n", __func__);

	if (!of_property_read_bool(dev->of_node, "#sound-dai-cells")) {
		dev_info(dev, "No \"#sound-dai-cells\", no audio\n");
		return 0;
	}

	ctx->audio.pdev = platform_device_register_data(dev,
							HDMI_CODEC_DRV_NAME,
							PLATFORM_DEVID_AUTO,
							&codec_data,
							sizeof(codec_data));

	if (IS_ERR(ctx->audio.pdev)) {
		dev_err(dev, "Failed to initialize HDMI audio codec: %d\n",
			PTR_ERR_OR_ZERO(ctx->audio.pdev));
	}

	return PTR_ERR_OR_ZERO(ctx->audio.pdev);
}

static const char * const it66121_supplies[] = {
	"vcn33", "vcn18", "vrf12"
};

static int it66121_probe(struct i2c_client *client)
{
	u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
	struct device_node *ep;
	int ret;
	struct it66121_ctx *ctx;
	struct device *dev = &client->dev;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(dev, "I2C check functionality failed.\n");
		return -ENXIO;
	}

	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
	if (!ep)
		return -EINVAL;

	ctx->dev = dev;
	ctx->client = client;
	ctx->info = i2c_get_match_data(client);

	of_property_read_u32(ep, "bus-width", &ctx->bus_width);
	of_node_put(ep);

	if (ctx->bus_width != 12 && ctx->bus_width != 24)
		return -EINVAL;

	ep = of_graph_get_remote_node(dev->of_node, 1, -1);
	if (!ep) {
		dev_err(ctx->dev, "The endpoint is unconnected\n");
		return -EINVAL;
	}

	if (!of_device_is_available(ep)) {
		of_node_put(ep);
		dev_err(ctx->dev, "The remote device is disabled\n");
		return -ENODEV;
	}

	ctx->next_bridge = of_drm_find_bridge(ep);
	of_node_put(ep);
	if (!ctx->next_bridge) {
		dev_dbg(ctx->dev, "Next bridge not found, deferring probe\n");
		return -EPROBE_DEFER;
	}

	i2c_set_clientdata(client, ctx);
	mutex_init(&ctx->lock);

	ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(it66121_supplies),
					     it66121_supplies);
	if (ret) {
		dev_err(dev, "Failed to enable power supplies\n");
		return ret;
	}

	it66121_hw_reset(ctx);

	ctx->regmap = devm_regmap_init_i2c(client, &it66121_regmap_config);
	if (IS_ERR(ctx->regmap))
		return PTR_ERR(ctx->regmap);

	regmap_read(ctx->regmap, IT66121_VENDOR_ID0_REG, &vendor_ids[0]);
	regmap_read(ctx->regmap, IT66121_VENDOR_ID1_REG, &vendor_ids[1]);
	regmap_read(ctx->regmap, IT66121_DEVICE_ID0_REG, &device_ids[0]);
	regmap_read(ctx->regmap, IT66121_DEVICE_ID1_REG, &device_ids[1]);

	/* Revision is shared with DEVICE_ID1 */
	revision_id = FIELD_GET(IT66121_REVISION_MASK, device_ids[1]);
	device_ids[1] &= IT66121_DEVICE_ID1_MASK;

	if ((vendor_ids[1] << 8 | vendor_ids[0]) != ctx->info->vid ||
	    (device_ids[1] << 8 | device_ids[0]) != ctx->info->pid) {
		return -ENODEV;
	}

	ctx->bridge.funcs = &it66121_bridge_funcs;
	ctx->bridge.of_node = dev->of_node;
	ctx->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
	ctx->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;

	ret = devm_request_threaded_irq(dev, client->irq, NULL,	it66121_irq_threaded_handler,
					IRQF_ONESHOT, dev_name(dev), ctx);
	if (ret < 0) {
		dev_err(dev, "Failed to request irq %d:%d\n", client->irq, ret);
		return ret;
	}

	it66121_audio_codec_init(ctx, dev);

	drm_bridge_add(&ctx->bridge);

	dev_info(ctx->dev, "IT66121 revision %d probed\n", revision_id);

	return 0;
}

static void it66121_remove(struct i2c_client *client)
{
	struct it66121_ctx *ctx = i2c_get_clientdata(client);

	drm_bridge_remove(&ctx->bridge);
	mutex_destroy(&ctx->lock);
}

static const struct it66121_chip_info it66121_chip_info = {
	.id = ID_IT66121,
	.vid = 0x4954,
	.pid = 0x0612,
};

static const struct it66121_chip_info it6610_chip_info = {
	.id = ID_IT6610,
	.vid = 0xca00,
	.pid = 0x0611,
};

static const struct of_device_id it66121_dt_match[] = {
	{ .compatible = "ite,it66121", &it66121_chip_info },
	{ .compatible = "ite,it6610", &it6610_chip_info },
	{ }
};
MODULE_DEVICE_TABLE(of, it66121_dt_match);

static const struct i2c_device_id it66121_id[] = {
	{ "it66121", (kernel_ulong_t) &it66121_chip_info },
	{ "it6610", (kernel_ulong_t) &it6610_chip_info },
	{ }
};
MODULE_DEVICE_TABLE(i2c, it66121_id);

static struct i2c_driver it66121_driver = {
	.driver = {
		.name	= "it66121",
		.of_match_table = it66121_dt_match,
	},
	.probe = it66121_probe,
	.remove = it66121_remove,
	.id_table = it66121_id,
};

module_i2c_driver(it66121_driver);

MODULE_AUTHOR("Phong LE");
MODULE_DESCRIPTION("IT66121 HDMI transmitter driver");
MODULE_LICENSE("GPL v2");