[PATCH 047/108] sound: Add an ACPI driver for Maxim MAX98357ac

Simon Glass sjg at chromium.org
Mon Jan 27 06:05:54 CET 2020


This chip is used on coral and we need to generate ACPI tables for sound
to make it work. Add a driver that does just this (i.e. at present does
not actually support playing sound).

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

 configs/sandbox_defconfig                    |   1 +
 doc/device-tree-bindings/sound/max98357a.txt |  22 ++++
 drivers/sound/Kconfig                        |   9 ++
 drivers/sound/Makefile                       |   1 +
 drivers/sound/max98357a.c                    | 109 +++++++++++++++++++
 5 files changed, 142 insertions(+)
 create mode 100644 doc/device-tree-bindings/sound/max98357a.txt
 create mode 100644 drivers/sound/max98357a.c

diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index cf1037f9a3..cbd9eea77a 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -197,6 +197,7 @@ CONFIG_SMEM=y
 CONFIG_SANDBOX_SMEM=y
 CONFIG_SOUND=y
 CONFIG_SOUND_DA7219=y
+CONFIG_SOUND_MAX98357A=y
 CONFIG_SOUND_SANDBOX=y
 CONFIG_SANDBOX_SPI=y
 CONFIG_SPMI=y
diff --git a/doc/device-tree-bindings/sound/max98357a.txt b/doc/device-tree-bindings/sound/max98357a.txt
new file mode 100644
index 0000000000..4bce14ce80
--- /dev/null
+++ b/doc/device-tree-bindings/sound/max98357a.txt
@@ -0,0 +1,22 @@
+Maxim MAX98357A audio DAC
+
+This node models the Maxim MAX98357A DAC.
+
+Required properties:
+- compatible   : "maxim,max98357a"
+
+Optional properties:
+- sdmode-gpios : GPIO specifier for the chip's SD_MODE pin.
+        If this option is not specified then driver does not manage
+        the pin state (e.g. chip is always on).
+- sdmode-delay : specify delay time for SD_MODE pin.
+        If this option is specified, which means it's required i2s clocks
+        ready before SD_MODE is unmuted in order to avoid the speaker pop noise.
+        It's observed that 5ms is sufficient.
+
+Example:
+
+max98357a {
+	compatible = "maxim,max98357a";
+	sdmode-gpios = <&qcom_pinmux 25 0>;
+};
diff --git a/drivers/sound/Kconfig b/drivers/sound/Kconfig
index 7f214b97be..0948d8caab 100644
--- a/drivers/sound/Kconfig
+++ b/drivers/sound/Kconfig
@@ -113,6 +113,15 @@ config SOUND_MAX98095
 	  audio data and I2C for codec control. At present it only works
 	  with the Samsung I2S driver.
 
+config SOUND_MAX98357A
+	bool "Support Maxim max98357a audio codec"
+	depends on PCI
+	help
+	  Enable the max98357a audio codec. This is connected on PCI for
+	  audio data codec control. This is currently only capable of providing
+	  ACPI information. A full driver (with sound in U-Boot) is currently
+	  not available.
+
 config SOUND_RT5677
 	bool "Support Realtek RT5677 audio codec"
 	depends on SOUND
diff --git a/drivers/sound/Makefile b/drivers/sound/Makefile
index 8c3933ad15..9b40c8012f 100644
--- a/drivers/sound/Makefile
+++ b/drivers/sound/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_SOUND_WM8994)	+= wm8994.o
 obj-$(CONFIG_SOUND_MAX98088)	+= max98088.o maxim_codec.o
 obj-$(CONFIG_SOUND_MAX98090)	+= max98090.o maxim_codec.o
 obj-$(CONFIG_SOUND_MAX98095)	+= max98095.o maxim_codec.o
+obj-$(CONFIG_SOUND_MAX98357A)	+= max98357a.o
 obj-$(CONFIG_SOUND_INTEL_HDA)	+= hda_codec.o
 obj-$(CONFIG_SOUND_I8254)	+= i8254_beep.o
 obj-$(CONFIG_SOUND_RT5677)	+= rt5677.o
diff --git a/drivers/sound/max98357a.c b/drivers/sound/max98357a.c
new file mode 100644
index 0000000000..63c336c27b
--- /dev/null
+++ b/drivers/sound/max98357a.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * max98357a.c -- MAX98357A Audio driver
+ *
+ * Copyright 2019 Google LLC
+ * Parts taken from coreboot
+ */
+
+#include <common.h>
+#include <acpigen.h>
+#include <acpi_device.h>
+#include <audio_codec.h>
+#include <dm.h>
+#include <sound.h>
+#include <asm-generic/gpio.h>
+#include <dm/acpi.h>
+
+struct max97357a_priv {
+	struct gpio_desc sdmode_gpio;
+};
+
+static int max97357a_ofdata_to_platdata(struct udevice *dev)
+{
+	struct max97357a_priv *priv = dev_get_priv(dev);
+
+	gpio_request_by_name(dev, "sdmode-gpios", 0, &priv->sdmode_gpio,
+			     GPIOD_IS_IN);
+
+	return 0;
+}
+
+static int max97357a_acpi_fill_ssdt(const struct udevice *dev,
+				    struct acpi_ctx *ctx)
+{
+	struct max97357a_priv *priv = dev_get_priv(dev);
+	char scope[ACPI_PATH_MAX];
+	char name[ACPI_NAME_MAX];
+	char path[ACPI_PATH_MAX];
+	struct acpi_dp *dp;
+	int ret;
+
+	ret = acpi_device_scope(dev, scope, sizeof(scope));
+	if (ret)
+		return log_msg_ret("scope", ret);
+	ret = acpi_device_name(dev, name);
+	if (ret)
+		return log_msg_ret("name", ret);
+
+	/* Device */
+	acpigen_write_scope(ctx, scope);
+	acpigen_write_device(ctx, name);
+	acpigen_write_name_string(ctx, "_HID",
+				  dev_read_string(dev, "acpi,hid"));
+	acpigen_write_name_integer(ctx, "_UID", 0);
+	acpigen_write_name_string(ctx, "_DDN",
+				  dev_read_string(dev, "acpi,desc"));
+	acpigen_write_sta(ctx, acpi_device_status(dev));
+
+	ret = acpi_device_write_gpio_desc(ctx, &priv->sdmode_gpio);
+	if (ret)
+		return log_msg_ret("gpio", ret);
+
+	/* Resources */
+	acpigen_write_name(ctx, "_CRS");
+	acpigen_write_resourcetemplate_header(ctx);
+	ret = acpi_device_write_gpio_desc(ctx, &priv->sdmode_gpio);
+	if (ret)
+		return log_msg_ret("gpio", ret);
+	acpigen_write_resourcetemplate_footer(ctx);
+
+	/* _DSD for devicetree properties */
+	/* This points to the first pin in the first gpio entry in _CRS */
+	ret = acpi_device_path(dev, path, sizeof(path));
+	if (ret)
+		return log_msg_ret("path", ret);
+	dp = acpi_dp_new_table("_DSD");
+	acpi_dp_add_gpio(dp, "sdmode-gpio", path, 0, 0,
+			 priv->sdmode_gpio.flags & GPIOD_ACTIVE_LOW ?
+			 ACPI_GPIO_ACTIVE_LOW : ACPI_GPIO_ACTIVE_HIGH);
+	acpi_dp_add_integer(dp, "sdmode-delay",
+			    dev_read_u32_default(dev, "sdmode-delay", 0));
+	acpi_dp_write(ctx, dp);
+
+	acpigen_pop_len(ctx); /* Device */
+	acpigen_pop_len(ctx); /* Scope */
+
+	return 0;
+}
+
+struct acpi_ops max97357a_acpi_ops = {
+	.fill_ssdt	= max97357a_acpi_fill_ssdt,
+};
+
+static const struct audio_codec_ops max98357a_ops = {
+};
+
+static const struct udevice_id max98357a_ids[] = {
+	{ .compatible = "maxim,max98357a" },
+	{ }
+};
+
+U_BOOT_DRIVER(max98357a) = {
+	.name		= "max98357a",
+	.id		= UCLASS_AUDIO_CODEC,
+	.of_match	= max98357a_ids,
+	.ofdata_to_platdata	= max97357a_ofdata_to_platdata,
+	.ops		= &max98357a_ops,
+	acpi_ops_ptr(&max97357a_acpi_ops)
+};
-- 
2.25.0.341.g760bfbb309-goog



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