ASoC: meson: add axg sound card support

Add the axg sound card to handle the specifities of the axg audio
sub system.

This card is required to:
 * setup the dpcm links specific to the AXG (with a cpu sound dai)
 * handle the 4 lanes masks of the tdm interfaces
 * add the loopback link when a tdm pad interface has a playback
   stream
 * handle multi-codec links

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 684 insertions, 0 deletions

diff --git a/sound/soc/meson/Kconfig b/sound/soc/meson/Kconfig
index 00d05df67b52..4cf93c05a982 100644
--- a/sound/soc/meson/Kconfig
+++ b/sound/soc/meson/Kconfig
@@ -43,6 +43,17 @@ config SND_MESON_AXG_TDMOUT
           Select Y or M to add support for TDM output formatter embedded
           in the Amlogic AXG SoC family
 
+config SND_MESON_AXG_SOUND_CARD
+        tristate "Amlogic AXG Sound Card Support"
+        select SND_MESON_AXG_TDM_INTERFACE
+        imply SND_MESON_AXG_FRDDR
+        imply SND_MESON_AXG_TODDR
+        imply SND_MESON_AXG_TDMIN
+        imply SND_MESON_AXG_TDMOUT
+        imply SND_MESON_AXG_SPDIFOUT
+        help
+          Select Y or M to add support for the AXG SoC sound card
+
 config SND_MESON_AXG_SPDIFOUT
         tristate "Amlogic AXG SPDIF Output Support"
         imply SND_SOC_SPDIF
diff --git a/sound/soc/meson/Makefile b/sound/soc/meson/Makefile
index f62833fb44d8..c5e003b093db 100644
--- a/sound/soc/meson/Makefile
+++ b/sound/soc/meson/Makefile
@@ -7,6 +7,7 @@ snd-soc-meson-axg-tdm-formatter-objs := axg-tdm-formatter.o
 snd-soc-meson-axg-tdm-interface-objs := axg-tdm-interface.o
 snd-soc-meson-axg-tdmin-objs := axg-tdmin.o
 snd-soc-meson-axg-tdmout-objs := axg-tdmout.o
+snd-soc-meson-axg-sound-card-objs := axg-card.o
 snd-soc-meson-axg-spdifout-objs := axg-spdifout.o
 
 obj-$(CONFIG_SND_MESON_AXG_FIFO) += snd-soc-meson-axg-fifo.o
@@ -16,4 +17,5 @@ obj-$(CONFIG_SND_MESON_AXG_TDM_FORMATTER) += snd-soc-meson-axg-tdm-formatter.o
 obj-$(CONFIG_SND_MESON_AXG_TDM_INTERFACE) += snd-soc-meson-axg-tdm-interface.o
 obj-$(CONFIG_SND_MESON_AXG_TDMIN) += snd-soc-meson-axg-tdmin.o
 obj-$(CONFIG_SND_MESON_AXG_TDMOUT) += snd-soc-meson-axg-tdmout.o
+obj-$(CONFIG_SND_MESON_AXG_SOUND_CARD) += snd-soc-meson-axg-sound-card.o
 obj-$(CONFIG_SND_MESON_AXG_SPDIFOUT) += snd-soc-meson-axg-spdifout.o
diff --git a/sound/soc/meson/axg-card.c b/sound/soc/meson/axg-card.c
new file mode 100644
index 000000000000..d6d1081d94ad
--- /dev/null
+++ b/sound/soc/meson/axg-card.c
@@ -0,0 +1,671 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+//
+// Copyright (c) 2018 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+
+#include "axg-tdm.h"
+
+struct axg_card {
+        struct snd_soc_card card;
+        void **link_data;
+};
+
+struct axg_dai_link_tdm_mask {
+        u32 tx;
+        u32 rx;
+};
+
+struct axg_dai_link_tdm_data {
+        unsigned int mclk_fs;
+        unsigned int slots;
+        unsigned int slot_width;
+        u32 *tx_mask;
+        u32 *rx_mask;
+        struct axg_dai_link_tdm_mask *codec_masks;
+};
+
+#define PREFIX "amlogic,"
+
+static int axg_card_reallocate_links(struct axg_card *priv,
+                                     unsigned int num_links)
+{
+        struct snd_soc_dai_link *links;
+        void **ldata;
+
+        links = krealloc(priv->card.dai_link,
+                         num_links * sizeof(*priv->card.dai_link),
+                         GFP_KERNEL | __GFP_ZERO);
+        ldata = krealloc(priv->link_data,
+                         num_links * sizeof(*priv->link_data),
+                         GFP_KERNEL | __GFP_ZERO);
+
+        if (!links || !ldata) {
+                dev_err(priv->card.dev, "failed to allocate links\n");
+                return -ENOMEM;
+        }
+
+        priv->card.dai_link = links;
+        priv->link_data = ldata;
+        priv->card.num_links = num_links;
+        return 0;
+}
+
+static int axg_card_parse_dai(struct snd_soc_card *card,
+                              struct device_node *node,
+                              struct device_node **dai_of_node,
+                              const char **dai_name)
+{
+        struct of_phandle_args args;
+        int ret;
+
+        if (!dai_name || !dai_of_node || !node)
+                return -EINVAL;
+
+        ret = of_parse_phandle_with_args(node, "sound-dai",
+                                         "#sound-dai-cells", 0, &args);
+        if (ret) {
+                if (ret != -EPROBE_DEFER)
+                        dev_err(card->dev, "can't parse dai %d\n", ret);
+                return ret;
+        }
+        *dai_of_node = args.np;
+
+        return snd_soc_get_dai_name(&args, dai_name);
+}
+
+static int axg_card_set_link_name(struct snd_soc_card *card,
+                                  struct snd_soc_dai_link *link,
+                                  const char *prefix)
+{
+        char *name = devm_kasprintf(card->dev, GFP_KERNEL, "%s.%s",
+                                    prefix, link->cpu_of_node->full_name);
+        if (!name)
+                return -ENOMEM;
+
+        link->name = name;
+        link->stream_name = name;
+
+        return 0;
+}
+
+static void axg_card_clean_references(struct axg_card *priv)
+{
+        struct snd_soc_card *card = &priv->card;
+        struct snd_soc_dai_link *link;
+        int i, j;
+
+        if (card->dai_link) {
+                for (i = 0; i < card->num_links; i++) {
+                        link = &card->dai_link[i];
+                        of_node_put(link->cpu_of_node);
+                        for (j = 0; j < link->num_codecs; j++)
+                                of_node_put(link->codecs[j].of_node);
+                }
+        }
+
+        if (card->aux_dev) {
+                for (i = 0; i < card->num_aux_devs; i++)
+                        of_node_put(card->aux_dev[i].codec_of_node);
+        }
+
+        kfree(card->dai_link);
+        kfree(priv->link_data);
+}
+
+static int axg_card_add_aux_devices(struct snd_soc_card *card)
+{
+        struct device_node *node = card->dev->of_node;
+        struct snd_soc_aux_dev *aux;
+        int num, i;
+
+        num = of_count_phandle_with_args(node, PREFIX "aux-devs", NULL);
+        if (num == -ENOENT) {
+                /*
+                 * It is ok to have no auxiliary devices but for this card it
+                 * is a strange situtation. Let's warn the about it.
+                 */
+                dev_warn(card->dev, "card has no auxiliary devices\n");
+                return 0;
+        } else if (num < 0) {
+                dev_err(card->dev, "error getting auxiliary devices: %d\n",
+                        num);
+                return num;
+        }
+
+        aux = devm_kcalloc(card->dev, num, sizeof(*aux), GFP_KERNEL);
+        if (!aux)
+                return -ENOMEM;
+        card->aux_dev = aux;
+        card->num_aux_devs = num;
+
+        for (i = 0; i < card->num_aux_devs; i++, aux++) {
+                aux->codec_of_node = of_parse_phandle(node,
+                                                      PREFIX "aux-devs", i);
+                if (!aux->codec_of_node)
+                        return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int axg_card_tdm_be_hw_params(struct snd_pcm_substream *substream,
+                                     struct snd_pcm_hw_params *params)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct axg_card *priv = snd_soc_card_get_drvdata(rtd->card);
+        struct axg_dai_link_tdm_data *be =
+                (struct axg_dai_link_tdm_data *)priv->link_data[rtd->num];
+        struct snd_soc_dai *codec_dai;
+        unsigned int mclk;
+        int ret, i;
+
+        if (be->mclk_fs) {
+                mclk = params_rate(params) * be->mclk_fs;
+
+                for (i = 0; i < rtd->num_codecs; i++) {
+                        codec_dai = rtd->codec_dais[i];
+                        ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
+                                                     SND_SOC_CLOCK_IN);
+                        if (ret && ret != -ENOTSUPP)
+                                return ret;
+                }
+
+                ret = snd_soc_dai_set_sysclk(rtd->cpu_dai, 0, mclk,
+                                             SND_SOC_CLOCK_OUT);
+                if (ret && ret != -ENOTSUPP)
+                        return ret;
+        }
+
+        return 0;
+}
+
+static const struct snd_soc_ops axg_card_tdm_be_ops = {
+        .hw_params = axg_card_tdm_be_hw_params,
+};
+
+static int axg_card_tdm_dai_init(struct snd_soc_pcm_runtime *rtd)
+{
+        struct axg_card *priv = snd_soc_card_get_drvdata(rtd->card);
+        struct axg_dai_link_tdm_data *be =
+                (struct axg_dai_link_tdm_data *)priv->link_data[rtd->num];
+        struct snd_soc_dai *codec_dai;
+        int ret, i;
+
+        for (i = 0; i < rtd->num_codecs; i++) {
+                codec_dai = rtd->codec_dais[i];
+                ret = snd_soc_dai_set_tdm_slot(codec_dai,
+                                               be->codec_masks[i].tx,
+                                               be->codec_masks[i].rx,
+                                               be->slots, be->slot_width);
+                if (ret && ret != -ENOTSUPP) {
+                        dev_err(codec_dai->dev,
+                                "setting tdm link slots failed\n");
+                        return ret;
+                }
+        }
+
+        ret = axg_tdm_set_tdm_slots(rtd->cpu_dai, be->tx_mask, be->rx_mask,
+                                    be->slots, be->slot_width);
+        if (ret) {
+                dev_err(rtd->cpu_dai->dev, "setting tdm link slots failed\n");
+                return ret;
+        }
+
+        return 0;
+}
+
+static int axg_card_tdm_dai_lb_init(struct snd_soc_pcm_runtime *rtd)
+{
+        struct axg_card *priv = snd_soc_card_get_drvdata(rtd->card);
+        struct axg_dai_link_tdm_data *be =
+                (struct axg_dai_link_tdm_data *)priv->link_data[rtd->num];
+        int ret;
+
+        /* The loopback rx_mask is the pad tx_mask */
+        ret = axg_tdm_set_tdm_slots(rtd->cpu_dai, NULL, be->tx_mask,
+                                    be->slots, be->slot_width);
+        if (ret) {
+                dev_err(rtd->cpu_dai->dev, "setting tdm link slots failed\n");
+                return ret;
+        }
+
+        return 0;
+}
+
+static int axg_card_add_tdm_loopback(struct snd_soc_card *card,
+                                     int *index)
+{
+        struct axg_card *priv = snd_soc_card_get_drvdata(card);
+        struct snd_soc_dai_link *pad = &card->dai_link[*index];
+        struct snd_soc_dai_link *lb;
+        int ret;
+
+        /* extend links */
+        ret = axg_card_reallocate_links(priv, card->num_links + 1);
+        if (ret)
+                return ret;
+
+        lb = &card->dai_link[*index + 1];
+
+        lb->name = kasprintf(GFP_KERNEL, "%s-lb", pad->name);
+        if (!lb->name)
+                return -ENOMEM;
+
+        lb->stream_name = lb->name;
+        lb->cpu_of_node = pad->cpu_of_node;
+        lb->cpu_dai_name = "TDM Loopback";
+        lb->codec_name = "snd-soc-dummy";
+        lb->codec_dai_name = "snd-soc-dummy-dai";
+        lb->dpcm_capture = 1;
+        lb->no_pcm = 1;
+        lb->ops = &axg_card_tdm_be_ops;
+        lb->init = axg_card_tdm_dai_lb_init;
+
+        /* Provide the same link data to the loopback */
+        priv->link_data[*index + 1] = priv->link_data[*index];
+
+        /*
+         * axg_card_clean_references() will iterate over this link,
+         * make sure the node count is balanced
+         */
+        of_node_get(lb->cpu_of_node);
+
+        /* Let add_links continue where it should */
+        *index += 1;
+
+        return 0;
+}
+
+static unsigned int axg_card_parse_daifmt(struct device_node *node,
+                                          struct device_node *cpu_node)
+{
+        struct device_node *bitclkmaster = NULL;
+        struct device_node *framemaster = NULL;
+        unsigned int daifmt;
+
+        daifmt = snd_soc_of_parse_daifmt(node, PREFIX,
+                                         &bitclkmaster, &framemaster);
+        daifmt &= ~SND_SOC_DAIFMT_MASTER_MASK;
+
+        /* If no master is provided, default to cpu master */
+        if (!bitclkmaster || bitclkmaster == cpu_node) {
+                daifmt |= (!framemaster || framemaster == cpu_node) ?
+                        SND_SOC_DAIFMT_CBS_CFS : SND_SOC_DAIFMT_CBS_CFM;
+        } else {
+                daifmt |= (!framemaster || framemaster == cpu_node) ?
+                        SND_SOC_DAIFMT_CBM_CFS : SND_SOC_DAIFMT_CBM_CFM;
+        }
+
+        of_node_put(bitclkmaster);
+        of_node_put(framemaster);
+
+        return daifmt;
+}
+
+static int axg_card_parse_cpu_tdm_slots(struct snd_soc_card *card,
+                                        struct snd_soc_dai_link *link,
+                                        struct device_node *node,
+                                        struct axg_dai_link_tdm_data *be)
+{
+        char propname[32];
+        u32 tx, rx;
+        int i;
+
+        be->tx_mask = devm_kcalloc(card->dev, AXG_TDM_NUM_LANES,
+                                   sizeof(*be->tx_mask), GFP_KERNEL);
+        be->rx_mask = devm_kcalloc(card->dev, AXG_TDM_NUM_LANES,
+                                   sizeof(*be->rx_mask), GFP_KERNEL);
+        if (!be->tx_mask || !be->rx_mask)
+                return -ENOMEM;
+
+        for (i = 0, tx = 0; i < AXG_TDM_NUM_LANES; i++) {
+                snprintf(propname, 32, "dai-tdm-slot-tx-mask-%d", i);
+                snd_soc_of_get_slot_mask(node, propname, &be->tx_mask[i]);
+                tx = max(tx, be->tx_mask[i]);
+        }
+
+        /* Disable playback is the interface has no tx slots */
+        if (!tx)
+                link->dpcm_playback = 0;
+
+        for (i = 0, rx = 0; i < AXG_TDM_NUM_LANES; i++) {
+                snprintf(propname, 32, "dai-tdm-slot-rx-mask-%d", i);
+                snd_soc_of_get_slot_mask(node, propname, &be->rx_mask[i]);
+                rx = max(rx, be->rx_mask[i]);
+        }
+
+        /* Disable capture is the interface has no rx slots */
+        if (!rx)
+                link->dpcm_capture = 0;
+
+        /* ... but the interface should at least have one of them */
+        if (!tx && !rx) {
+                dev_err(card->dev, "tdm link has no cpu slots\n");
+                return -EINVAL;
+        }
+
+        of_property_read_u32(node, "dai-tdm-slot-num", &be->slots);
+        if (!be->slots) {
+                /*
+                 * If the slot number is not provided, set it such as it
+                 * accommodates the largest mask
+                 */
+                be->slots = fls(max(tx, rx));
+        } else if (be->slots < fls(max(tx, rx)) || be->slots > 32) {
+                /*
+                 * Error if the slots can't accommodate the largest mask or
+                 * if it is just too big
+                 */
+                dev_err(card->dev, "bad slot number\n");
+                return -EINVAL;
+        }
+
+        of_property_read_u32(node, "dai-tdm-slot-width", &be->slot_width);
+
+        return 0;
+}
+
+static int axg_card_parse_codecs_masks(struct snd_soc_card *card,
+                                       struct snd_soc_dai_link *link,
+                                       struct device_node *node,
+                                       struct axg_dai_link_tdm_data *be)
+{
+        struct axg_dai_link_tdm_mask *codec_mask;
+        struct device_node *np;
+
+        codec_mask = devm_kcalloc(card->dev, link->num_codecs,
+                                  sizeof(*codec_mask), GFP_KERNEL);
+        if (!codec_mask)
+                return -ENOMEM;
+
+        be->codec_masks = codec_mask;
+
+        for_each_child_of_node(node, np) {
+                snd_soc_of_get_slot_mask(np, "dai-tdm-slot-rx-mask",
+                                         &codec_mask->rx);
+                snd_soc_of_get_slot_mask(np, "dai-tdm-slot-tx-mask",
+                                         &codec_mask->tx);
+
+                codec_mask++;
+        }
+
+        return 0;
+}
+
+static int axg_card_parse_tdm(struct snd_soc_card *card,
+                              struct device_node *node,
+                              int *index)
+{
+        struct axg_card *priv = snd_soc_card_get_drvdata(card);
+        struct snd_soc_dai_link *link = &card->dai_link[*index];
+        struct axg_dai_link_tdm_data *be;
+        int ret;
+
+        /* Allocate tdm link parameters */
+        be = devm_kzalloc(card->dev, sizeof(*be), GFP_KERNEL);
+        if (!be)
+                return -ENOMEM;
+        priv->link_data[*index] = be;
+
+        /* Setup tdm link */
+        link->ops = &axg_card_tdm_be_ops;
+        link->init = axg_card_tdm_dai_init;
+        link->dai_fmt = axg_card_parse_daifmt(node, link->cpu_of_node);
+
+        of_property_read_u32(node, "mclk-fs", &be->mclk_fs);
+
+        ret = axg_card_parse_cpu_tdm_slots(card, link, node, be);
+        if (ret) {
+                dev_err(card->dev, "error parsing tdm link slots\n");
+                return ret;
+        }
+
+        ret = axg_card_parse_codecs_masks(card, link, node, be);
+        if (ret)
+                return ret;
+
+        /* Add loopback if the pad dai has playback */
+        if (link->dpcm_playback) {
+                ret = axg_card_add_tdm_loopback(card, index);
+                if (ret)
+                        return ret;
+        }
+
+        return 0;
+}
+
+static int axg_card_set_be_link(struct snd_soc_card *card,
+                                struct snd_soc_dai_link *link,
+                                struct device_node *node)
+{
+        struct snd_soc_dai_link_component *codec;
+        struct device_node *np;
+        int ret, num_codecs;
+
+        link->no_pcm = 1;
+        link->dpcm_playback = 1;
+        link->dpcm_capture = 1;
+
+        num_codecs = of_get_child_count(node);
+        if (!num_codecs) {
+                dev_err(card->dev, "be link %s has no codec\n",
+                        node->full_name);
+                return -EINVAL;
+        }
+
+        codec = devm_kcalloc(card->dev, num_codecs, sizeof(*codec), GFP_KERNEL);
+        if (!codec)
+                return -ENOMEM;
+
+        link->codecs = codec;
+        link->num_codecs = num_codecs;
+
+        for_each_child_of_node(node, np) {
+                ret = axg_card_parse_dai(card, np, &codec->of_node,
+                                         &codec->dai_name);
+                if (ret) {
+                        of_node_put(np);
+                        return ret;
+                }
+
+                codec++;
+        }
+
+        ret = axg_card_set_link_name(card, link, "be");
+        if (ret)
+                dev_err(card->dev, "error setting %s link name\n", np->name);
+
+        return ret;
+}
+
+static int axg_card_set_fe_link(struct snd_soc_card *card,
+                                struct snd_soc_dai_link *link,
+                                bool is_playback)
+{
+        link->dynamic = 1;
+        link->dpcm_merged_format = 1;
+        link->dpcm_merged_chan = 1;
+        link->dpcm_merged_rate = 1;
+        link->codec_dai_name = "snd-soc-dummy-dai";
+        link->codec_name = "snd-soc-dummy";
+
+        if (is_playback)
+                link->dpcm_playback = 1;
+        else
+                link->dpcm_capture = 1;
+
+        return axg_card_set_link_name(card, link, "fe");
+}
+
+static int axg_card_cpu_is_capture_fe(struct device_node *np)
+{
+        return of_device_is_compatible(np, PREFIX "axg-toddr");
+}
+
+static int axg_card_cpu_is_playback_fe(struct device_node *np)
+{
+        return of_device_is_compatible(np, PREFIX "axg-frddr");
+}
+
+static int axg_card_cpu_is_tdm_iface(struct device_node *np)
+{
+        return of_device_is_compatible(np, PREFIX "axg-tdm-iface");
+}
+
+static int axg_card_add_link(struct snd_soc_card *card, struct device_node *np,
+                             int *index)
+{
+        struct snd_soc_dai_link *dai_link = &card->dai_link[*index];
+        int ret;
+
+        ret = axg_card_parse_dai(card, np, &dai_link->cpu_of_node,
+                                 &dai_link->cpu_dai_name);
+        if (ret)
+                return ret;
+
+        if (axg_card_cpu_is_playback_fe(dai_link->cpu_of_node))
+                ret = axg_card_set_fe_link(card, dai_link, true);
+        else if (axg_card_cpu_is_capture_fe(dai_link->cpu_of_node))
+                ret = axg_card_set_fe_link(card, dai_link, false);
+        else
+                ret = axg_card_set_be_link(card, dai_link, np);
+
+        if (ret)
+                return ret;
+
+        if (axg_card_cpu_is_tdm_iface(dai_link->cpu_of_node))
+                ret = axg_card_parse_tdm(card, np, index);
+
+        return ret;
+}
+
+static int axg_card_add_links(struct snd_soc_card *card)
+{
+        struct axg_card *priv = snd_soc_card_get_drvdata(card);
+        struct device_node *node = card->dev->of_node;
+        struct device_node *np;
+        int num, i, ret;
+
+        num = of_get_child_count(node);
+        if (!num) {
+                dev_err(card->dev, "card has no links\n");
+                return -EINVAL;
+        }
+
+        ret = axg_card_reallocate_links(priv, num);
+        if (ret)
+                return ret;
+
+        i = 0;
+        for_each_child_of_node(node, np) {
+                ret = axg_card_add_link(card, np, &i);
+                if (ret) {
+                        of_node_put(np);
+                        return ret;
+                }
+
+                i++;
+        }
+
+        return 0;
+}
+
+static int axg_card_parse_of_optional(struct snd_soc_card *card,
+                                      const char *propname,
+                                      int (*func)(struct snd_soc_card *c,
+                                                  const char *p))
+{
+        /* If property is not provided, don't fail ... */
+        if (!of_property_read_bool(card->dev->of_node, propname))
+                return 0;
+
+        /* ... but do fail if it is provided and the parsing fails */
+        return func(card, propname);
+}
+
+static const struct of_device_id axg_card_of_match[] = {
+        { .compatible = "amlogic,axg-sound-card", },
+        {}
+};
+MODULE_DEVICE_TABLE(of, axg_card_of_match);
+
+static int axg_card_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct axg_card *priv;
+        int ret;
+
+        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, priv);
+        snd_soc_card_set_drvdata(&priv->card, priv);
+
+        priv->card.owner = THIS_MODULE;
+        priv->card.dev = dev;
+
+        ret = snd_soc_of_parse_card_name(&priv->card, PREFIX "name");
+        if (ret < 0)
+                return ret;
+
+        ret = axg_card_parse_of_optional(&priv->card, PREFIX "routing",
+                                         snd_soc_of_parse_audio_routing);
+        if (ret) {
+                dev_err(dev, "error while parsing routing\n");
+                return ret;
+        }
+
+        ret = axg_card_parse_of_optional(&priv->card, PREFIX "widgets",
+                                         snd_soc_of_parse_audio_simple_widgets);
+        if (ret) {
+                dev_err(dev, "error while parsing widgets\n");
+                return ret;
+        }
+
+        ret = axg_card_add_links(&priv->card);
+        if (ret)
+                goto out_err;
+
+        ret = axg_card_add_aux_devices(&priv->card);
+        if (ret)
+                goto out_err;
+
+        ret = devm_snd_soc_register_card(dev, &priv->card);
+        if (ret)
+                goto out_err;
+
+        return 0;
+
+out_err:
+        axg_card_clean_references(priv);
+        return ret;
+}
+
+static int axg_card_remove(struct platform_device *pdev)
+{
+        struct axg_card *priv = platform_get_drvdata(pdev);
+
+        axg_card_clean_references(priv);
+
+        return 0;
+}
+
+static struct platform_driver axg_card_pdrv = {
+        .probe = axg_card_probe,
+        .remove = axg_card_remove,
+        .driver = {
+                .name = "axg-sound-card",
+                .of_match_table = axg_card_of_match,
+        },
+};
+module_platform_driver(axg_card_pdrv);
+
+MODULE_DESCRIPTION("Amlogic AXG ALSA machine driver");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_LICENSE("GPL v2");