drm/bridge: anx7625: add HDMI audio function

Add audio HDMI codec function support, enable it through device true
flag "analogix,audio-enable".
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211104033857.2634562-1-xji@analogixsemi.com

drivers/gpu/drm/bridge/analogix/anx7625.c

@@ -33,6 +33,7 @@
 #include <drm/drm_probe_helper.h>
 
 #include <media/v4l2-fwnode.h>
+#include <sound/hdmi-codec.h>
 #include <video/display_timing.h>
 
 #include "anx7625.h"
@@ -153,6 +154,20 @@ static int anx7625_write_and(struct anx7625_data *ctx,
 	return anx7625_reg_write(ctx, client, offset, (val & (mask)));
 }
 
+static int anx7625_write_and_or(struct anx7625_data *ctx,
+				struct i2c_client *client,
+				u8 offset, u8 and_mask, u8 or_mask)
+{
+	int val;
+
+	val = anx7625_reg_read(ctx, client, offset);
+	if (val < 0)
+		return val;
+
+	return anx7625_reg_write(ctx, client,
+				 offset, (val & and_mask) | (or_mask));
+}
+
 static int anx7625_config_bit_matrix(struct anx7625_data *ctx)
 {
 	int i, ret;
@@ -1353,6 +1368,9 @@ static int anx7625_parse_dt(struct device *dev,
 	else
 		DRM_DEV_DEBUG_DRIVER(dev, "found MIPI DSI host node.\n");
 
+	if (of_property_read_bool(np, "analogix,audio-enable"))
+		pdata->audio_en = 1;
+
 	ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
 	if (ret < 0) {
 		if (ret == -ENODEV)
@@ -1423,6 +1441,208 @@ static enum drm_connector_status anx7625_sink_detect(struct anx7625_data *ctx)
 				     connector_status_disconnected;
 }
 
+static int anx7625_audio_hw_params(struct device *dev, void *data,
+				   struct hdmi_codec_daifmt *fmt,
+				   struct hdmi_codec_params *params)
+{
+	struct anx7625_data *ctx = dev_get_drvdata(dev);
+	int wl, ch, rate;
+	int ret = 0;
+
+	if (fmt->fmt != HDMI_DSP_A) {
+		DRM_DEV_ERROR(dev, "only supports DSP_A\n");
+		return -EINVAL;
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "setting %d Hz, %d bit, %d channels\n",
+			     params->sample_rate, params->sample_width,
+			     params->cea.channels);
+
+	ret |= anx7625_write_and_or(ctx, ctx->i2c.tx_p2_client,
+				    AUDIO_CHANNEL_STATUS_6,
+				    ~I2S_SLAVE_MODE,
+				    TDM_SLAVE_MODE);
+
+	/* Word length */
+	switch (params->sample_width) {
+	case 16:
+		wl = AUDIO_W_LEN_16_20MAX;
+		break;
+	case 18:
+		wl = AUDIO_W_LEN_18_20MAX;
+		break;
+	case 20:
+		wl = AUDIO_W_LEN_20_20MAX;
+		break;
+	case 24:
+		wl = AUDIO_W_LEN_24_24MAX;
+		break;
+	default:
+		DRM_DEV_DEBUG_DRIVER(dev, "wordlength: %d bit not support",
+				     params->sample_width);
+		return -EINVAL;
+	}
+	ret |= anx7625_write_and_or(ctx, ctx->i2c.tx_p2_client,
+				    AUDIO_CHANNEL_STATUS_5,
+				    0xf0, wl);
+
+	/* Channel num */
+	switch (params->cea.channels) {
+	case 2:
+		ch = I2S_CH_2;
+		break;
+	case 4:
+		ch = TDM_CH_4;
+		break;
+	case 6:
+		ch = TDM_CH_6;
+		break;
+	case 8:
+		ch = TDM_CH_8;
+		break;
+	default:
+		DRM_DEV_DEBUG_DRIVER(dev, "channel number: %d not support",
+				     params->cea.channels);
+		return -EINVAL;
+	}
+	ret |= anx7625_write_and_or(ctx, ctx->i2c.tx_p2_client,
+			       AUDIO_CHANNEL_STATUS_6, 0x1f, ch << 5);
+	if (ch > I2S_CH_2)
+		ret |= anx7625_write_or(ctx, ctx->i2c.tx_p2_client,
+				AUDIO_CHANNEL_STATUS_6, AUDIO_LAYOUT);
+	else
+		ret |= anx7625_write_and(ctx, ctx->i2c.tx_p2_client,
+				AUDIO_CHANNEL_STATUS_6, ~AUDIO_LAYOUT);
+
+	/* FS */
+	switch (params->sample_rate) {
+	case 32000:
+		rate = AUDIO_FS_32K;
+		break;
+	case 44100:
+		rate = AUDIO_FS_441K;
+		break;
+	case 48000:
+		rate = AUDIO_FS_48K;
+		break;
+	case 88200:
+		rate = AUDIO_FS_882K;
+		break;
+	case 96000:
+		rate = AUDIO_FS_96K;
+		break;
+	case 176400:
+		rate = AUDIO_FS_1764K;
+		break;
+	case 192000:
+		rate = AUDIO_FS_192K;
+		break;
+	default:
+		DRM_DEV_DEBUG_DRIVER(dev, "sample rate: %d not support",
+				     params->sample_rate);
+		return -EINVAL;
+	}
+	ret |= anx7625_write_and_or(ctx, ctx->i2c.tx_p2_client,
+				    AUDIO_CHANNEL_STATUS_4,
+				    0xf0, rate);
+	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p0_client,
+				AP_AV_STATUS, AP_AUDIO_CHG);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "IO error : config audio.\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void anx7625_audio_shutdown(struct device *dev, void *data)
+{
+	DRM_DEV_DEBUG_DRIVER(dev, "stop audio\n");
+}
+
+static int anx7625_hdmi_i2s_get_dai_id(struct snd_soc_component *component,
+				       struct device_node *endpoint)
+{
+	struct of_endpoint of_ep;
+	int ret;
+
+	ret = of_graph_parse_endpoint(endpoint, &of_ep);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * HDMI sound should be located at external DPI port
+	 * Didn't have good way to check where is internal(DSI)
+	 * or external(DPI) bridge
+	 */
+	return 0;
+}
+
+static void
+anx7625_audio_update_connector_status(struct anx7625_data *ctx,
+				      enum drm_connector_status status)
+{
+	if (ctx->plugged_cb && ctx->codec_dev) {
+		ctx->plugged_cb(ctx->codec_dev,
+				status == connector_status_connected);
+	}
+}
+
+static int anx7625_audio_hook_plugged_cb(struct device *dev, void *data,
+					 hdmi_codec_plugged_cb fn,
+					 struct device *codec_dev)
+{
+	struct anx7625_data *ctx = data;
+
+	ctx->plugged_cb = fn;
+	ctx->codec_dev = codec_dev;
+	anx7625_audio_update_connector_status(ctx, anx7625_sink_detect(ctx));
+
+	return 0;
+}
+
+static const struct hdmi_codec_ops anx7625_codec_ops = {
+	.hw_params	= anx7625_audio_hw_params,
+	.audio_shutdown = anx7625_audio_shutdown,
+	.get_dai_id	= anx7625_hdmi_i2s_get_dai_id,
+	.hook_plugged_cb = anx7625_audio_hook_plugged_cb,
+};
+
+static void anx7625_unregister_audio(struct anx7625_data *ctx)
+{
+	struct device *dev = &ctx->client->dev;
+
+	if (ctx->audio_pdev) {
+		platform_device_unregister(ctx->audio_pdev);
+		ctx->audio_pdev = NULL;
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "unbound to %s", HDMI_CODEC_DRV_NAME);
+}
+
+static int anx7625_register_audio(struct device *dev, struct anx7625_data *ctx)
+{
+	struct hdmi_codec_pdata codec_data = {
+		.ops = &anx7625_codec_ops,
+		.max_i2s_channels = 8,
+		.i2s = 1,
+		.data = ctx,
+	};
+
+	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))
+		return IS_ERR(ctx->audio_pdev);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "bound to %s", HDMI_CODEC_DRV_NAME);
+
+	return 0;
+}
+
 static int anx7625_attach_dsi(struct anx7625_data *ctx)
 {
 	struct mipi_dsi_device *dsi;
@@ -1974,6 +2194,9 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 		}
 	}
 
+	if (platform->pdata.audio_en)
+		anx7625_register_audio(dev, platform);
+
 	DRM_DEV_DEBUG_DRIVER(dev, "probe done\n");
 
 	return 0;
@@ -2010,6 +2233,9 @@ static int anx7625_i2c_remove(struct i2c_client *client)
 
 	anx7625_unregister_i2c_dummy_clients(platform);
 
+	if (platform->pdata.audio_en)
+		anx7625_unregister_audio(platform);
+
 	kfree(platform);
 	return 0;
 }

drivers/gpu/drm/bridge/analogix/anx7625.h

@@ -111,6 +111,7 @@
 #define AUDIO_CHANNEL_STATUS_6 0xd5
 #define TDM_SLAVE_MODE 0x10
 #define I2S_SLAVE_MODE 0x08
+#define AUDIO_LAYOUT   0x01
 
 #define AUDIO_CONTROL_REGISTER 0xe6
 #define TDM_TIMING_MODE 0x08
@@ -367,6 +368,7 @@ struct anx7625_platform_data {
 	int intp_irq;
 	int is_dpi;
 	int mipi_lanes;
+	int audio_en;
 	int dp_lane0_swing_reg_cnt;
 	int lane0_reg_data[DP_TX_SWING_REG_CNT];
 	int dp_lane1_swing_reg_cnt;
@@ -387,6 +389,7 @@ struct anx7625_i2c_client {
 
 struct anx7625_data {
 	struct anx7625_platform_data pdata;
+	struct platform_device *audio_pdev;
 	int hpd_status;
 	int hpd_high_cnt;
 	/* Lock for work queue */
@@ -395,6 +398,8 @@ struct anx7625_data {
 	struct anx7625_i2c_client i2c;
 	struct i2c_client *last_client;
 	struct s_edid_data slimport_edid_p;
+	struct device *codec_dev;
+	hdmi_codec_plugged_cb plugged_cb;
 	struct work_struct work;
 	struct workqueue_struct *workqueue;
 	char edid_block;