dm: sound: Create a uclass for sound

The sound driver pulls together the audio codec and i2s drivers in order
to actually make sounds. It supports setup() and play() methods. The
sound_find_codec_i2s() function allows locating the linked codec and i2s
devices. They can be referred to from uclass-private data.

Add a uclass and a test for sound.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/sound/sound-uclass.c b/drivers/sound/sound-uclass.c
new file mode 100644
index 0000000..71e753c
--- /dev/null
+++ b/drivers/sound/sound-uclass.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2s.h>
+#include <sound.h>
+
+#define SOUND_BITS_IN_BYTE 8
+
+int sound_setup(struct udevice *dev)
+{
+	struct sound_ops *ops = sound_get_ops(dev);
+
+	if (!ops->setup)
+		return -ENOSYS;
+
+	return ops->setup(dev);
+}
+
+int sound_play(struct udevice *dev, void *data, uint data_size)
+{
+	struct sound_ops *ops = sound_get_ops(dev);
+
+	if (!ops->play)
+		return -ENOSYS;
+
+	return ops->play(dev, data, data_size);
+}
+
+int sound_beep(struct udevice *dev, int msecs, int frequency_hz)
+{
+	struct sound_uc_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct i2s_uc_priv *i2s_uc_priv = dev_get_uclass_priv(uc_priv->i2s);
+	unsigned short *data;
+	uint data_size;
+	int ret;
+
+	ret = sound_setup(dev);
+	if (ret && ret != -EALREADY)
+		return ret;
+
+	/* Buffer length computation */
+	data_size = i2s_uc_priv->samplingrate * i2s_uc_priv->channels;
+	data_size *= (i2s_uc_priv->bitspersample / SOUND_BITS_IN_BYTE);
+	data = malloc(data_size);
+	if (!data) {
+		debug("%s: malloc failed\n", __func__);
+		return -ENOMEM;
+	}
+
+	sound_create_square_wave(i2s_uc_priv->samplingrate, data, data_size,
+				 frequency_hz);
+
+	while (msecs >= 1000) {
+		ret = sound_play(dev, data, data_size);
+		msecs -= 1000;
+	}
+	if (msecs) {
+		unsigned long size =
+			(data_size * msecs) / (sizeof(int) * 1000);
+
+		ret = sound_play(dev, data, size);
+	}
+
+	free(data);
+
+	return ret;
+}
+
+int sound_find_codec_i2s(struct udevice *dev)
+{
+	struct sound_uc_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct ofnode_phandle_args args;
+	ofnode node;
+	int ret;
+
+	/* First the codec */
+	node = ofnode_find_subnode(dev_ofnode(dev), "codec");
+	if (!ofnode_valid(node)) {
+		debug("Failed to find /cpu subnode\n");
+		return -EINVAL;
+	}
+	ret = ofnode_parse_phandle_with_args(node, "sound-dai",
+					     "#sound-dai-cells", 0, 0, &args);
+	if (ret) {
+		debug("Cannot find phandle: %d\n", ret);
+		return ret;
+	}
+	ret = uclass_get_device_by_ofnode(UCLASS_AUDIO_CODEC, args.node,
+					  &uc_priv->codec);
+	if (ret) {
+		debug("Cannot find codec: %d\n", ret);
+		return ret;
+	}
+
+	/* Now the i2s */
+	node = ofnode_find_subnode(dev_ofnode(dev), "cpu");
+	if (!ofnode_valid(node)) {
+		debug("Failed to find /cpu subnode\n");
+		return -EINVAL;
+	}
+	ret = ofnode_parse_phandle_with_args(node, "sound-dai",
+					     "#sound-dai-cells", 0, 0, &args);
+	if (ret) {
+		debug("Cannot find phandle: %d\n", ret);
+		return ret;
+	}
+	ret = uclass_get_device_by_ofnode(UCLASS_I2S, args.node, &uc_priv->i2s);
+	if (ret) {
+		debug("Cannot find i2s: %d\n", ret);
+		return ret;
+	}
+	debug("Probed sound '%s' with codec '%s' and i2s '%s'\n", dev->name,
+	      uc_priv->codec->name, uc_priv->i2s->name);
+
+	return 0;
+}
+
+UCLASS_DRIVER(sound) = {
+	.id		= UCLASS_SOUND,
+	.name		= "sound",
+	.per_device_auto_alloc_size	= sizeof(struct sound_uc_priv),
+};