msm: mdss: hdmi: Add support for new HDMI-Audio interface

Using this new interface, HDMI-Audio codec driver can retrieve
sink's audio capabilities. Based on this supported capabilities
and current playback clip, it will pass appropriate audio setup
information to HDMI driver for configuration.

Change-Id: Ia52f72d955778859c381a5e6c94aba57e40d13b2
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>

Documentation/devicetree/bindings/fb/msm-hdmi-tx.txt

@@ -21,6 +21,14 @@ Required properties:
 
 - <compatible-name>-<gpio-name>: specifies gpios assigned for the device.
 
+[Optional child nodes]: These nodes are for devices which are
+dependent on HDMI Tx controller. If HDMI Tx controller is disabled then
+these devices will be disabled as well. Ex. HDMI Audio Codec device.
+
+- qcom,msm-hdmi-audio-rx: Node for HDMI audio codec.
+Required properties:
+- compatible : "msm-hdmi-audio-codec-rx";
+
 Example:
 	qcom,hdmi_tx@fd922100 {
 		cell-index = <0>;
@@ -43,4 +51,8 @@ Example:
 		qcom,hdmi-tx-ddc-clk = <&msmgpio 32 0>;
 		qcom,hdmi-tx-ddc-data = <&msmgpio 33 0>;
 		qcom,hdmi-tx-hpd = <&msmgpio 34 0>;
+
+		qcom,msm-hdmi-audio-rx {
+			compatible = "qcom,msm-hdmi-audio-codec-rx";
+		};
 	};

arch/arm/mach-msm/include/mach/msm_hdmi_audio_codec.h

@@ -0,0 +1,37 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __MSM_HDMI_AUDIO_CODEC_H__
+#define __MSM_HDMI_AUDIO_CODEC_H__
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+
+struct msm_hdmi_audio_edid_blk {
+	u8 *audio_data_blk;
+	unsigned int audio_data_blk_size; /* in bytes */
+	u8 *spk_alloc_data_blk;
+	unsigned int spk_alloc_data_blk_size; /* in bytes */
+};
+
+struct msm_hdmi_audio_codec_ops {
+	int (*audio_info_setup)(struct platform_device *pdev,
+		u32 num_of_channels, u32 channel_allocation, u32 level_shift,
+		bool down_mix);
+	int (*get_audio_edid_blk) (struct platform_device *pdev,
+		struct msm_hdmi_audio_edid_blk *blk);
+};
+
+int msm_hdmi_register_audio_codec(struct platform_device *pdev,
+	struct msm_hdmi_audio_codec_ops *ops);
+
+#endif /* __MSM_HDMI_AUDIO_CODEC_H__ */

drivers/video/fbdev/msm/mdss_hdmi_edid.c

@@ -19,6 +19,14 @@
 #define HDMI_VSDB_3D_EVF_DATA_OFFSET(vsd) \
 	(!((vsd)[8] & BIT(7)) ? 9 : (!((vsd)[8] & BIT(6)) ? 11 : 13))
 
+/*
+ * As per the CEA-861E spec, there can be a total of 10 short audio
+ * descriptors with each SAD being 3 bytes long.
+ * Thus, the maximum length of the audio data block would be 30 bytes
+ */
+#define MAX_AUDIO_DATA_BLOCK_SIZE	30
+#define MAX_SPKR_ALLOC_DATA_BLOCK_SIZE	3
+
 struct hdmi_edid_sink_data {
 	u32 disp_mode_list[HDMI_VFRMT_MAX];
 	u32 disp_3d_mode_list[HDMI_VFRMT_MAX];
@@ -35,11 +43,13 @@ struct hdmi_edid_ctrl {
 	u16 physical_address;
 	u32 video_resolution; /* selected by user */
 	u32 sink_mode; /* HDMI or DVI */
-	u8 speaker_allocation_block;
-	u8 audio_data_block_cnt;
 	u16 audio_latency;
 	u16 video_latency;
 	u32 present_3d;
+	u8 audio_data_block[MAX_AUDIO_DATA_BLOCK_SIZE];
+	int adb_size;
+	u8 spkr_alloc_data_block[MAX_SPKR_ALLOC_DATA_BLOCK_SIZE];
+	int sadb_size;
 
 	struct hdmi_edid_sink_data sink_data;
 	struct hdmi_edid_init_data init_data;
@@ -551,26 +561,28 @@ static void hdmi_edid_extract_3d_present(struct hdmi_edid_ctrl *edid_ctrl,
 static void hdmi_edid_extract_audio_data_blocks(
 	struct hdmi_edid_ctrl *edid_ctrl, const u8 *in_buf)
 {
-	u8 len;
-	const u8 *sad = NULL;
+	u8 len, cnt = 0;
+	const u8 *adb = NULL;
 
 	if (!edid_ctrl) {
 		DEV_ERR("%s: invalid input\n", __func__);
 		return;
 	}
 
-	sad = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 1, &len);
-	if (sad == NULL)
+	adb = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 1, &len);
+	if ((adb == NULL) || (len > MAX_AUDIO_DATA_BLOCK_SIZE))
 		return;
 
-	edid_ctrl->audio_data_block_cnt = 0;
-	while (len >= 3 && edid_ctrl->audio_data_block_cnt < 16) {
-		DEV_DBG("%s: ch=%d fmt=%d sampling=0x%02x bitdepth=0x%02x\n",
-			__func__, (sad[1]&0x7)+1, sad[1]>>3, sad[2], sad[3]);
+	memcpy(edid_ctrl->audio_data_block, adb + 1, len);
+	edid_ctrl->adb_size = len;
 
-		++edid_ctrl->audio_data_block_cnt;
+	while (len >= 3 && cnt < 16) {
+		DEV_DBG("%s: ch=%d fmt=%d sampling=0x%02x bitdepth=0x%02x\n",
+			__func__, (adb[1]&0x7)+1, adb[1]>>3, adb[2], adb[3]);
+
+		cnt++;
 		len -= 3;
-		sad += 3;
+		adb += 3;
 	}
 } /* hdmi_edid_extract_audio_data_blocks */
 
@@ -578,27 +590,29 @@ static void hdmi_edid_extract_speaker_allocation_data(
 	struct hdmi_edid_ctrl *edid_ctrl, const u8 *in_buf)
 {
 	u8 len;
-	const u8 *sad = NULL;
+	const u8 *sadb = NULL;
 
 	if (!edid_ctrl) {
 		DEV_ERR("%s: invalid input\n", __func__);
 		return;
 	}
 
-	sad = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 4, &len);
-	if (sad == NULL)
+	sadb = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 4, &len);
+	if ((sadb == NULL) || (len != MAX_SPKR_ALLOC_DATA_BLOCK_SIZE))
 		return;
 
-	edid_ctrl->speaker_allocation_block = sad[1];
+	memcpy(edid_ctrl->spkr_alloc_data_block, sadb + 1, len);
+	edid_ctrl->sadb_size = len;
+
 	DEV_DBG("%s: EDID: speaker alloc data SP byte = %08x %s%s%s%s%s%s%s\n",
-		__func__, sad[1],
-		(sad[1] & BIT(0)) ? "FL/FR," : "",
-		(sad[1] & BIT(1)) ? "LFE," : "",
-		(sad[1] & BIT(2)) ? "FC," : "",
-		(sad[1] & BIT(3)) ? "RL/RR," : "",
-		(sad[1] & BIT(4)) ? "RC," : "",
-		(sad[1] & BIT(5)) ? "FLC/FRC," : "",
-		(sad[1] & BIT(6)) ? "RLC/RRC," : "");
+		__func__, sadb[1],
+		(sadb[1] & BIT(0)) ? "FL/FR," : "",
+		(sadb[1] & BIT(1)) ? "LFE," : "",
+		(sadb[1] & BIT(2)) ? "FC," : "",
+		(sadb[1] & BIT(3)) ? "RL/RR," : "",
+		(sadb[1] & BIT(4)) ? "RC," : "",
+		(sadb[1] & BIT(5)) ? "FLC/FRC," : "",
+		(sadb[1] & BIT(6)) ? "RLC/RRC," : "");
 } /* hdmi_edid_extract_speaker_allocation_data */
 
 static void hdmi_edid_extract_latency_fields(struct hdmi_edid_ctrl *edid_ctrl,
@@ -1225,6 +1239,12 @@ int hdmi_edid_read(void *input)
 	edid_ctrl->present_3d = 0;
 	memset(&edid_ctrl->sink_data, 0, sizeof(edid_ctrl->sink_data));
 	memset(edid_buf, 0, sizeof(edid_buf));
+	memset(edid_ctrl->audio_data_block, 0,
+		sizeof(edid_ctrl->audio_data_block));
+	memset(edid_ctrl->spkr_alloc_data_block, 0,
+		sizeof(edid_ctrl->spkr_alloc_data_block));
+	edid_ctrl->adb_size = 0;
+	edid_ctrl->sadb_size = 0;
 
 	status = hdmi_edid_read_block(edid_ctrl, 0, edid_buf);
 	if (status || !hdmi_edid_check_header(edid_buf)) {
@@ -1401,6 +1421,24 @@ u32 hdmi_edid_get_sink_mode(void *input)
 	return edid_ctrl->sink_mode;
 } /* hdmi_edid_get_sink_mode */
 
+int hdmi_edid_get_audio_blk(void *input, struct msm_hdmi_audio_edid_blk *blk)
+{
+	struct hdmi_edid_ctrl *edid_ctrl = (struct hdmi_edid_ctrl *)input;
+
+	if (!edid_ctrl || !blk) {
+		DEV_ERR("%s: invalid input\n", __func__);
+		return -EINVAL;
+	}
+
+	blk->audio_data_blk = edid_ctrl->audio_data_block;
+	blk->audio_data_blk_size = edid_ctrl->adb_size;
+
+	blk->spk_alloc_data_blk = edid_ctrl->spkr_alloc_data_block;
+	blk->spk_alloc_data_blk_size = edid_ctrl->sadb_size;
+
+	return 0;
+} /* hdmi_edid_get_audio_blk */
+
 void hdmi_edid_set_video_resolution(void *input, u32 resolution)
 {
 	struct hdmi_edid_ctrl *edid_ctrl = (struct hdmi_edid_ctrl *)input;

drivers/video/fbdev/msm/mdss_hdmi_edid.h

@@ -13,6 +13,7 @@
 #ifndef __HDMI_EDID_H__
 #define __HDMI_EDID_H__
 
+#include <mach/msm_hdmi_audio_codec.h>
 #include "mdss_hdmi_util.h"
 
 struct hdmi_edid_init_data {
@@ -26,6 +27,8 @@ struct hdmi_edid_init_data {
 int hdmi_edid_read(void *edid_ctrl);
 u8 hdmi_edid_get_sink_scaninfo(void *edid_ctrl, u32 resolution);
 u32 hdmi_edid_get_sink_mode(void *edid_ctrl);
+int hdmi_edid_get_audio_blk(void *edid_ctrl,
+	struct msm_hdmi_audio_edid_blk *blk);
 void hdmi_edid_set_video_resolution(void *edid_ctrl, u32 resolution);
 void hdmi_edid_deinit(void *edid_ctrl);
 void *hdmi_edid_init(struct hdmi_edid_init_data *init_data);

drivers/video/fbdev/msm/mdss_hdmi_tx.c

@@ -18,8 +18,9 @@
 #include <linux/iopoll.h>
 #include <linux/of_address.h>
 #include <linux/of_gpio.h>
+#include <linux/of_platform.h>
 #include <linux/types.h>
-#include <mach/msm_hdmi_audio.h>
+#include <mach/msm_hdmi_audio_codec.h>
 
 #define REG_DUMP 0
 
@@ -49,6 +50,23 @@
 /* Enable HDCP by default */
 static bool hdcp_feature_on = true;
 
+/* Supported HDMI Audio channels */
+#define MSM_HDMI_AUDIO_CHANNEL_2	2
+#define MSM_HDMI_AUDIO_CHANNEL_4	4
+#define MSM_HDMI_AUDIO_CHANNEL_6	6
+#define MSM_HDMI_AUDIO_CHANNEL_8	8
+
+enum msm_hdmi_supported_audio_sample_rates {
+	AUDIO_SAMPLE_RATE_32KHZ,
+	AUDIO_SAMPLE_RATE_44_1KHZ,
+	AUDIO_SAMPLE_RATE_48KHZ,
+	AUDIO_SAMPLE_RATE_88_2KHZ,
+	AUDIO_SAMPLE_RATE_96KHZ,
+	AUDIO_SAMPLE_RATE_176_4KHZ,
+	AUDIO_SAMPLE_RATE_192KHZ,
+	AUDIO_SAMPLE_RATE_MAX
+};
+
 /* parameters for clock regeneration */
 struct hdmi_tx_audio_acr {
 	u32 n;
@@ -57,7 +75,7 @@ struct hdmi_tx_audio_acr {
 
 struct hdmi_tx_audio_acr_arry {
 	u32 pclk;
-	struct hdmi_tx_audio_acr lut[HDMI_SAMPLE_RATE_MAX];
+	struct hdmi_tx_audio_acr lut[AUDIO_SAMPLE_RATE_MAX];
 };
 
 static int hdmi_tx_sysfs_enable_hpd(struct hdmi_tx_ctrl *hdmi_ctrl, int on);
@@ -1508,13 +1526,13 @@ static int hdmi_tx_audio_acr_setup(struct hdmi_tx_ctrl *hdmi_ctrl,
 		layout = (MSM_HDMI_AUDIO_CHANNEL_2 == num_of_channels) ? 0 : 1;
 
 		if (
-		(HDMI_SAMPLE_RATE_192KHZ == hdmi_ctrl->audio_sample_rate) ||
-		(HDMI_SAMPLE_RATE_176_4KHZ == hdmi_ctrl->audio_sample_rate)) {
+		(AUDIO_SAMPLE_RATE_192KHZ == hdmi_ctrl->audio_sample_rate) ||
+		(AUDIO_SAMPLE_RATE_176_4KHZ == hdmi_ctrl->audio_sample_rate)) {
 			multiplier = 4;
 			n >>= 2; /* divide N by 4 and use multiplier */
 		} else if (
-		(HDMI_SAMPLE_RATE_96KHZ == hdmi_ctrl->audio_sample_rate) ||
-		(HDMI_SAMPLE_RATE_88_2KHZ == hdmi_ctrl->audio_sample_rate)) {
+		(AUDIO_SAMPLE_RATE_96KHZ == hdmi_ctrl->audio_sample_rate) ||
+		(AUDIO_SAMPLE_RATE_88_2KHZ == hdmi_ctrl->audio_sample_rate)) {
 			multiplier = 2;
 			n >>= 1; /* divide N by 2 and use multiplier */
 		} else {
@@ -1528,9 +1546,9 @@ static int hdmi_tx_audio_acr_setup(struct hdmi_tx_ctrl *hdmi_ctrl,
 		/* N_MULTIPLE(multiplier) */
 		acr_pck_ctrl_reg |= (multiplier & 7) << 16;
 
-		if ((HDMI_SAMPLE_RATE_48KHZ == hdmi_ctrl->audio_sample_rate) ||
-		(HDMI_SAMPLE_RATE_96KHZ == hdmi_ctrl->audio_sample_rate) ||
-		(HDMI_SAMPLE_RATE_192KHZ == hdmi_ctrl->audio_sample_rate)) {
+		if ((AUDIO_SAMPLE_RATE_48KHZ == hdmi_ctrl->audio_sample_rate) ||
+		(AUDIO_SAMPLE_RATE_96KHZ == hdmi_ctrl->audio_sample_rate) ||
+		(AUDIO_SAMPLE_RATE_192KHZ == hdmi_ctrl->audio_sample_rate)) {
 			/* SELECT(3) */
 			acr_pck_ctrl_reg |= 3 << 4;
 			/* CTS_48 */
@@ -1541,9 +1559,9 @@ static int hdmi_tx_audio_acr_setup(struct hdmi_tx_ctrl *hdmi_ctrl,
 			/* N */
 			DSS_REG_W(io, HDMI_ACR_48_1, n);
 		} else if (
-		(HDMI_SAMPLE_RATE_44_1KHZ == hdmi_ctrl->audio_sample_rate) ||
-		(HDMI_SAMPLE_RATE_88_2KHZ == hdmi_ctrl->audio_sample_rate) ||
-		(HDMI_SAMPLE_RATE_176_4KHZ == hdmi_ctrl->audio_sample_rate)) {
+		(AUDIO_SAMPLE_RATE_44_1KHZ == hdmi_ctrl->audio_sample_rate) ||
+		(AUDIO_SAMPLE_RATE_88_2KHZ == hdmi_ctrl->audio_sample_rate) ||
+		(AUDIO_SAMPLE_RATE_176_4KHZ == hdmi_ctrl->audio_sample_rate)) {
 			/* SELECT(2) */
 			acr_pck_ctrl_reg |= 2 << 4;
 			/* CTS_44 */
@@ -1581,11 +1599,10 @@ static int hdmi_tx_audio_acr_setup(struct hdmi_tx_ctrl *hdmi_ctrl,
 	return 0;
 } /* hdmi_tx_audio_acr_setup */
 
-static int hdmi_tx_audio_info_setup(void *priv_d, bool enabled,
-	u32 num_of_channels, u32 channel_allocation, u32 level_shift,
-	bool down_mix)
+static int hdmi_tx_audio_iframe_setup(struct hdmi_tx_ctrl *hdmi_ctrl,
+	bool enabled, u32 num_of_channels, u32 channel_allocation,
+	u32 level_shift, bool down_mix)
 {
-	struct hdmi_tx_ctrl *hdmi_ctrl = (struct hdmi_tx_ctrl *)priv_d;
 	struct dss_io_data *io = NULL;
 
 	u32 channel_count = 1; /* Def to 2 channels -> Table 17 in CEA-D */
@@ -1630,22 +1647,15 @@ static int hdmi_tx_audio_info_setup(void *priv_d, bool enabled,
 	if (enabled) {
 		switch (num_of_channels) {
 		case MSM_HDMI_AUDIO_CHANNEL_2:
-			channel_allocation = 0;	/* Default to FR, FL */
 			break;
 		case MSM_HDMI_AUDIO_CHANNEL_4:
 			channel_count = 3;
-			/* FC, LFE, FR, FL */
-			channel_allocation = 0x3;
 			break;
 		case MSM_HDMI_AUDIO_CHANNEL_6:
 			channel_count = 5;
-			/* RR, RL, FC, LFE, FR, FL */
-			channel_allocation = 0xB;
 			break;
 		case MSM_HDMI_AUDIO_CHANNEL_8:
 			channel_count = 7;
-			/* FRC, FLC, RR, RL, FC, LFE, FR, FL */
-			channel_allocation = 0x1f;
 			break;
 		default:
 			DEV_ERR("%s: Unsupported num_of_channels = %u\n",
@@ -1712,9 +1722,67 @@ static int hdmi_tx_audio_info_setup(void *priv_d, bool enabled,
 	dss_reg_dump(io->base, io->len,
 		enabled ? "HDMI-AUDIO-ON: " : "HDMI-AUDIO-OFF: ", REG_DUMP);
 
+	return 0;
+} /* hdmi_tx_audio_iframe_setup */
+
+static int hdmi_tx_audio_info_setup(struct platform_device *pdev,
+	u32 num_of_channels, u32 channel_allocation, u32 level_shift,
+	bool down_mix)
+{
+	int rc = 0;
+	struct hdmi_tx_ctrl *hdmi_ctrl = platform_get_drvdata(pdev);
+
+	if (!hdmi_ctrl) {
+		DEV_ERR("%s: invalid input\n", __func__);
+		return -ENODEV;
+	}
+
+	if (hdmi_ctrl->panel_power_on) {
+		rc = hdmi_tx_audio_iframe_setup(hdmi_ctrl, true,
+			num_of_channels, channel_allocation, level_shift,
+			down_mix);
+		if (rc)
+			DEV_ERR("%s: hdmi_tx_audio_iframe_setup failed.rc=%d\n",
+				__func__, rc);
+	} else {
+		DEV_ERR("%s: Error. panel is not on.\n", __func__);
+		rc = -EPERM;
+	}
+
 	return 0;
 } /* hdmi_tx_audio_info_setup */
 
+static int hdmi_tx_get_audio_edid_blk(struct platform_device *pdev,
+	struct msm_hdmi_audio_edid_blk *blk)
+{
+	struct hdmi_tx_ctrl *hdmi_ctrl = platform_get_drvdata(pdev);
+
+	if (!hdmi_ctrl) {
+		DEV_ERR("%s: invalid input\n", __func__);
+		return -ENODEV;
+	}
+
+	return hdmi_edid_get_audio_blk(
+		hdmi_ctrl->feature_data[HDMI_TX_FEAT_EDID], blk);
+} /* hdmi_tx_get_audio_edid_blk */
+
+int msm_hdmi_register_audio_codec(struct platform_device *pdev,
+	struct msm_hdmi_audio_codec_ops *ops)
+{
+	struct hdmi_tx_ctrl *hdmi_ctrl = platform_get_drvdata(pdev);
+
+	if (!hdmi_ctrl) {
+		DEV_ERR("%s: invalid input\n", __func__);
+		return -ENODEV;
+	}
+
+	ops->audio_info_setup = hdmi_tx_audio_info_setup;
+	ops->get_audio_edid_blk = hdmi_tx_get_audio_edid_blk;
+
+	return 0;
+} /* hdmi_tx_audio_register */
+EXPORT_SYMBOL(msm_hdmi_register_audio_codec);
+
 static int hdmi_tx_audio_setup(struct hdmi_tx_ctrl *hdmi_ctrl)
 {
 	int rc = 0;
@@ -1739,9 +1807,9 @@ static int hdmi_tx_audio_setup(struct hdmi_tx_ctrl *hdmi_ctrl)
 		return rc;
 	}
 
-	rc = hdmi_tx_audio_info_setup(hdmi_ctrl, true, channels, 0, 0, false);
+	rc = hdmi_tx_audio_iframe_setup(hdmi_ctrl, true, channels, 0, 0, false);
 	if (rc) {
-		DEV_ERR("%s: hdmi_tx_audio_info_setup failed. rc=%d\n",
+		DEV_ERR("%s: hdmi_tx_audio_iframe_setup failed. rc=%d\n",
 			__func__, rc);
 		return rc;
 	}
@@ -1788,8 +1856,8 @@ static void hdmi_tx_audio_off(struct hdmi_tx_ctrl *hdmi_ctrl)
 	if (i == timeout_sec)
 		DEV_ERR("%s: Error: cannot turn off audio engine\n", __func__);
 
-	if (hdmi_tx_audio_info_setup(hdmi_ctrl, false, 0, 0, 0, false))
-		DEV_ERR("%s: hdmi_tx_audio_info_setup failed.\n", __func__);
+	if (hdmi_tx_audio_iframe_setup(hdmi_ctrl, false, 0, 0, 0, false))
+		DEV_ERR("%s: hdmi_tx_audio_iframe_setup failed.\n", __func__);
 
 	if (hdmi_tx_audio_acr_setup(hdmi_ctrl, false, 0))
 		DEV_ERR("%s: hdmi_tx_audio_acr_setup failed.\n", __func__);
@@ -2243,7 +2311,7 @@ static int hdmi_tx_dev_init(struct hdmi_tx_ctrl *hdmi_ctrl)
 
 	INIT_WORK(&hdmi_ctrl->power_off_work, hdmi_tx_power_off_work);
 
-	hdmi_ctrl->audio_sample_rate = HDMI_SAMPLE_RATE_48KHZ;
+	hdmi_ctrl->audio_sample_rate = AUDIO_SAMPLE_RATE_48KHZ;
 
 	hdmi_ctrl->sdev.name = "hdmi";
 	if (switch_dev_register(&hdmi_ctrl->sdev) < 0) {
@@ -3026,6 +3094,15 @@ static int hdmi_tx_probe(struct platform_device *pdev)
 		goto failed_init_features;
 	}
 
+	rc = of_platform_populate(of_node, NULL, NULL, &pdev->dev);
+	if (rc) {
+		DEV_ERR("%s: failed to add child devices, rc=%d\n",
+			__func__, rc);
+		goto failed_init_features;
+	} else {
+		DEV_DBG("%s: added child devices.\n", __func__);
+	}
+
 	return rc;
 
 failed_init_features: