dm: sound: Create a uclass for i2s

The i2s bus is commonly used with audio codecs. It provides a way to
stream digital data sychronously in both directions. U-Boot only supports
audio output, so this uclass is very simple, with a single tx_data()
method.

Add a uclass and a test for i2s.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/sandbox/dts/test.dts

@@ -47,7 +47,7 @@
 		#sound-dai-cells = <1>;
 	};
 
-		cros_ec: cros-ec {
+	cros_ec: cros-ec {
 		reg = <0 0>;
 		compatible = "google,cros-ec-sandbox";
 
@@ -378,6 +378,11 @@
 		u-boot,dm-pre-reloc;
 	};
 
+	i2s: i2s {
+		compatible = "sandbox,i2s";
+		#sound-dai-cells = <1>;
+	};
+
 	misc-test {
 		compatible = "sandbox,misc_sandbox";
 	};

arch/sandbox/include/asm/test.h

@@ -131,4 +131,14 @@ void sandbox_get_codec_params(struct udevice *dev, int *interfacep, int *ratep,
 			      int *mclk_freqp, int *bits_per_samplep,
 			      uint *channelsp);
 
+/**
+ * sandbox_get_i2s_sum() - Read back the sum of the audio data so far
+ *
+ * This data is provided to the sandbox driver by the I2S tx_data() method.
+ *
+ * @dev: Device to check
+ * @return sum of audio data
+ */
+int sandbox_get_i2s_sum(struct udevice *dev);
+
 #endif

drivers/sound/Makefile

@@ -5,6 +5,7 @@
 
 obj-$(CONFIG_SOUND)	+= sound.o
 obj-$(CONFIG_DM_SOUND)	+= codec-uclass.o
+obj-$(CONFIG_DM_SOUND)	+= i2s-uclass.o
 obj-$(CONFIG_I2S)	+= sound-i2s.o
 obj-$(CONFIG_I2S_SAMSUNG)	+= samsung-i2s.o
 obj-$(CONFIG_SOUND_SANDBOX)	+= sandbox.o

drivers/sound/i2s-uclass.c

@@ -0,0 +1,25 @@
+// 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>
+
+int i2s_tx_data(struct udevice *dev, void *data, uint data_size)
+{
+	struct i2s_ops *ops = i2s_get_ops(dev);
+
+	if (!ops->tx_data)
+		return -ENOSYS;
+
+	return ops->tx_data(dev, data, data_size);
+}
+
+UCLASS_DRIVER(i2s) = {
+	.id		= UCLASS_I2S,
+	.name		= "i2s",
+	.per_device_auto_alloc_size	= sizeof(struct i2s_uc_priv),
+};

drivers/sound/sandbox.c

@@ -4,8 +4,9 @@
  */
 
 #include <common.h>
-#include <dm.h>
 #include <audio_codec.h>
+#include <dm.h>
+#include <i2s.h>
 #include <asm/sound.h>
 #include <asm/sdl.h>
 
@@ -17,6 +18,10 @@ struct sandbox_codec_priv {
 	uint channels;
 };
 
+struct sandbox_i2s_priv {
+	int sum;	/* Use to sum the provided audio data */
+};
+
 int sound_play(uint32_t msec, uint32_t frequency)
 {
 	sandbox_sdl_sound_start(frequency);
@@ -44,6 +49,13 @@ void sandbox_get_codec_params(struct udevice *dev, int *interfacep, int *ratep,
 	*channelsp = priv->channels;
 }
 
+int sandbox_get_i2s_sum(struct udevice *dev)
+{
+	struct sandbox_i2s_priv *priv = dev_get_priv(dev);
+
+	return priv->sum;
+}
+
 static int sandbox_codec_set_params(struct udevice *dev, int interface,
 				    int rate, int mclk_freq,
 				    int bits_per_sample, uint channels)
@@ -59,6 +71,34 @@ static int sandbox_codec_set_params(struct udevice *dev, int interface,
 	return 0;
 }
 
+static int sandbox_i2s_tx_data(struct udevice *dev, void *data,
+			       uint data_size)
+{
+	struct sandbox_i2s_priv *priv = dev_get_priv(dev);
+	int i;
+
+	for (i = 0; i < data_size; i++)
+		priv->sum += ((uint8_t *)data)[i];
+
+	return 0;
+}
+
+static int sandbox_i2s_probe(struct udevice *dev)
+{
+	struct i2s_uc_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	/* Use hard-coded values here */
+	uc_priv->rfs = 256;
+	uc_priv->bfs = 32;
+	uc_priv->audio_pll_clk = 192000000;
+	uc_priv->samplingrate = 48000;
+	uc_priv->bitspersample = 16;
+	uc_priv->channels = 2;
+	uc_priv->id = 1;
+
+	return 0;
+}
+
 static const struct audio_codec_ops sandbox_codec_ops = {
 	.set_params	= sandbox_codec_set_params,
 };
@@ -75,3 +115,21 @@ U_BOOT_DRIVER(sandbox_codec) = {
 	.ops		= &sandbox_codec_ops,
 	.priv_auto_alloc_size	= sizeof(struct sandbox_codec_priv),
 };
+
+static const struct i2s_ops sandbox_i2s_ops = {
+	.tx_data	= sandbox_i2s_tx_data,
+};
+
+static const struct udevice_id sandbox_i2s_ids[] = {
+	{ .compatible = "sandbox,i2s" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_i2s) = {
+	.name		= "sandbox_i2s",
+	.id		= UCLASS_I2S,
+	.of_match	= sandbox_i2s_ids,
+	.ops		= &sandbox_i2s_ops,
+	.probe		= sandbox_i2s_probe,
+	.priv_auto_alloc_size	= sizeof(struct sandbox_i2s_priv),
+};

include/dm/uclass-id.h

@@ -49,6 +49,7 @@ enum uclass_id {
 	UCLASS_I2C_EEPROM,	/* I2C EEPROM device */
 	UCLASS_I2C_GENERIC,	/* Generic I2C device */
 	UCLASS_I2C_MUX,		/* I2C multiplexer */
+	UCLASS_I2S,		/* I2S bus */
 	UCLASS_IDE,		/* IDE device */
 	UCLASS_IRQ,		/* Interrupt controller */
 	UCLASS_KEYBOARD,	/* Keyboard input device */

include/i2s.h

@@ -87,17 +87,41 @@ struct i2s_uc_priv {
 	unsigned int id;		/* I2S controller id */
 };
 
+/* Operations for i2s devices */
+struct i2s_ops {
+	/**
+	 * tx_data() - Transmit audio data
+	 *
+	 * @dev: I2C device
+	 * @data: Data buffer to play
+	 * @data_size: Size of data buffer in bytes
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*tx_data)(struct udevice *dev, void *data, uint data_size);
+};
+
+#define i2s_get_ops(dev)	((struct i2s_ops *)(dev)->driver->ops)
+
+/**
+ * i2s_tx_data() - Transmit audio data
+ *
+ * @dev: I2C device
+ * @data: Data buffer to play
+ * @data_size: Size of data buffer in bytes
+ * @return 0 if OK, -ve on error
+ */
+int i2s_tx_data(struct udevice *dev, void *data, uint data_size);
+
 /*
  * Sends the given data through i2s tx
  *
  * @param pi2s_tx	pointer of i2s transmitter parameter structure.
  * @param data		address of the data buffer
- * @param data_size	array size of the int buffer (total size / size of int)
+ * @param data_size	size of the data (in bytes)
- *
  * @return		int value 0 for success, -1 in case of error
  */
-int i2s_transfer_tx_data(struct i2s_uc_priv *pi2s_tx, unsigned int *data,
+int i2s_transfer_tx_data(struct i2s_uc_priv *pi2s_tx, void *data,
-			 unsigned long data_size);
+			 uint data_size);
 
 /*
  * Initialise i2s transmiter

test/dm/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_FIRMWARE) += firmware.o
 obj-$(CONFIG_DM_GPIO) += gpio.o
 obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock.o
 obj-$(CONFIG_DM_I2C) += i2c.o
+obj-$(CONFIG_DM_SOUND) += i2s.o
 obj-$(CONFIG_LED) += led.o
 obj-$(CONFIG_DM_MAILBOX) += mailbox.o
 obj-$(CONFIG_DM_MMC) += mmc.o

test/dm/i2s.c

@@ -0,0 +1,32 @@
+// 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 <dm/test.h>
+#include <test/ut.h>
+#include <asm/test.h>
+
+/* Basic test of the i2s codec uclass */
+static int dm_test_i2s(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	u8 data[3];
+
+	/* check probe success */
+	ut_assertok(uclass_first_device_err(UCLASS_I2S, &dev));
+	data[0] = 1;
+	data[1] = 4;
+	data[2] = 6;
+	ut_assertok(i2s_tx_data(dev, data, ARRAY_SIZE(data)));
+	ut_asserteq(11, sandbox_get_i2s_sum(dev));
+	ut_assertok(i2s_tx_data(dev, data, 1));
+	ut_asserteq(12, sandbox_get_i2s_sum(dev));
+
+	return 0;
+}
+DM_TEST(dm_test_i2s, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);