4 files changed, 216 insertions, 0 deletions
diff --git a/src/drivers/i2c/nau8825/Kconfig b/src/drivers/i2c/nau8825/Kconfig
new file mode 100644
index 0000000000..d2bdd028b8
--- /dev/null
+++ b/src/drivers/i2c/nau8825/Kconfig
@@ -0,0 +1,2 @@
+config DRIVERS_I2C_NAU8825
+	bool
diff --git a/src/drivers/i2c/nau8825/Makefile.inc b/src/drivers/i2c/nau8825/Makefile.inc
new file mode 100644
index 0000000000..6f32643439
--- /dev/null
+++ b/src/drivers/i2c/nau8825/Makefile.inc
@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_I2C_NAU8825) += nau8825.c
diff --git a/src/drivers/i2c/nau8825/chip.h b/src/drivers/i2c/nau8825/chip.h
new file mode 100644
index 0000000000..e6c88bc4e7
--- /dev/null
+++ b/src/drivers/i2c/nau8825/chip.h
@@ -0,0 +1,96 @@
+#include <arch/acpi_device.h>
+
+#define NAU8825_MAX_BUTTONS 8
+
+/*
+ * Nuvoton NAU8825 audio codec devicetree bindings
+ * linux/Documentation/devicetree/bindings/sound/nau8825.txt
+ */
+struct drivers_i2c_nau8825_config {
+	/* Interrupt configuration */
+	struct acpi_irq irq;
+
+	/* I2C Bus Frequency in Hertz (default 400kHz) */
+	unsigned bus_speed;
+
+	/* Enable jack detection via JKDET pin */
+	unsigned jkdet_enable;
+
+	/* Enable JKDET pin pull if set, otherwise high impedance state */
+	unsigned jkdet_pull_enable;
+
+	/* Pull-up JKDET pin if set, otherwise pull down */
+	unsigned jkdet_pull_up;
+
+	/* JKDET pin polarity, 0 => active high, 1 => active low */
+	unsigned jkdet_polarity;
+
+	/*
+	 * VREF Impedance selection
+	 *  0 - Open
+	 *  1 - 25 kOhm
+	 *  2 - 125 kOhm
+	 *  3 - 2.5 kOhm
+	 */
+	unsigned vref_impedance;
+
+	/* Button impedance measurement hysteresis */
+	unsigned sar_hysteresis;
+
+	/*
+	 * Reference voltage for button impedance measurement and micbias
+	 *  0 - VDDA
+	 *  1 - VDDA
+	 *  2 - VDDA * 1.1
+	 *  3 - VDDA * 1.2
+	 *  4 - VDDA * 1.3
+	 *  5 - VDDA * 1.4
+	 *  6 - VDDA * 1.53
+	 *  7 - VDDA * 1.53
+	 */
+	unsigned micbias_voltage;
+	unsigned sar_voltage;
+
+	/*
+	 * SAR compare time
+	 *  0 - 500 ns
+	 *  1 - 1 us
+	 *  2 - 2 us
+	 *  3 - 4 us
+	 */
+	unsigned sar_compare_time;
+
+	/*
+	 * SAR sampling time
+	 *  0 - 2 us
+	 *  1 - 4 us
+	 *  2 - 8 us
+	 *  3 - 16 us
+	 */
+	unsigned sar_sampling_time;
+
+	/*
+	 * Button short key press debounce time
+	 *  0 - 30 ms
+	 *  1 - 50 ms
+	 *  2 - 100 ms
+	 *  3 - 30 ms
+	 */
+	unsigned short_key_debounce;
+
+	/* Debounce time 2^(n+2) ms (0-7) for jack insert */
+	unsigned jack_insert_debounce;
+
+	/* Debounce time 2^(n+2) ms (0-7) for jack eject */
+	unsigned jack_eject_debounce;
+
+	/* Number of buttons supported, up to 8 */
+	unsigned sar_threshold_num;
+
+	/*
+	 * Impedance threshold for each button, up to 8
+	 *  SAR = 255 * micbias_voltage / sar_voltage * R / (2000 + R)
+	 *  R is Button impedance
+	 */
+	uint64_t sar_threshold[NAU8825_MAX_BUTTONS];
+};
diff --git a/src/drivers/i2c/nau8825/nau8825.c b/src/drivers/i2c/nau8825/nau8825.c
new file mode 100644
index 0000000000..71aaceaf15
--- /dev/null
+++ b/src/drivers/i2c/nau8825/nau8825.c
@@ -0,0 +1,117 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <arch/acpi.h>
+#include <arch/acpi_device.h>
+#include <arch/acpigen.h>
+#include <console/console.h>
+#include <device/i2c.h>
+#include <device/device.h>
+#include <device/path.h>
+#include <stdint.h>
+#include <string.h>
+#include "chip.h"
+
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+
+#define NAU8825_ACPI_NAME	"NAU8"
+#define NAU8825_ACPI_HID	"10508825"
+#define NAU8825_DP_INT(key,val)	acpi_dp_write_integer("nuvoton," key, (val))
+
+static void nau8825_fill_ssdt(struct device *dev)
+{
+	struct drivers_i2c_nau8825_config *config = dev->chip_info;
+	const char *scope = acpi_device_scope(dev);
+	struct acpi_i2c i2c = {
+		.address = dev->path.i2c.device,
+		.mode_10bit = dev->path.i2c.mode_10bit,
+		.speed = config->bus_speed ? : I2C_SPEED_FAST,
+		.resource = scope,
+	};
+
+	if (!dev->enabled || !scope)
+		return;
+	if (config->sar_threshold_num > NAU8825_MAX_BUTTONS)
+		return;
+
+	/* Device */
+	acpigen_write_scope(scope);
+	acpigen_write_device(acpi_device_name(dev));
+	acpigen_write_name_string("_HID", NAU8825_ACPI_HID);
+	acpigen_write_name_integer("_UID", 0);
+	acpigen_write_name_string("_DDN", dev->chip_ops->name);
+	acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_ON);
+
+	/* Resources */
+	acpigen_write_name("_CRS");
+	acpigen_write_resourcetemplate_header();
+	acpi_device_write_i2c(&i2c);
+	acpi_device_write_interrupt(&config->irq);
+	acpigen_write_resourcetemplate_footer();
+
+	/* Device Properties */
+	acpi_dp_write_header();
+	NAU8825_DP_INT("jkdet-enable", config->jkdet_enable);
+	NAU8825_DP_INT("jkdet-pull-enable", config->jkdet_pull_enable);
+	NAU8825_DP_INT("jkdet-pull-up", config->jkdet_pull_up);
+	NAU8825_DP_INT("jkdet-polarity", config->jkdet_polarity);
+	NAU8825_DP_INT("vref-impedance", config->vref_impedance);
+	NAU8825_DP_INT("micbias-voltage", config->micbias_voltage);
+	NAU8825_DP_INT("sar-hysteresis", config->sar_hysteresis);
+	NAU8825_DP_INT("sar-voltage", config->sar_voltage);
+	NAU8825_DP_INT("sar-compare-time", config->sar_compare_time);
+	NAU8825_DP_INT("sar-sampling-time", config->sar_sampling_time);
+	NAU8825_DP_INT("short-key-debounce", config->short_key_debounce);
+	NAU8825_DP_INT("jack-insert-debounce", config->jack_insert_debounce);
+	NAU8825_DP_INT("jack-eject-deboune", config->jack_eject_debounce);
+	NAU8825_DP_INT("sar-threshold-num", config->sar_threshold_num);
+	acpi_dp_write_integer_array("nuvoton,sar-threshold",
+				    config->sar_threshold,
+				    config->sar_threshold_num);
+	acpi_dp_write_footer();
+
+	acpigen_pop_len(); /* Device */
+	acpigen_pop_len(); /* Scope */
+
+	printk(BIOS_INFO, "%s: %s address 0%xh irq %d\n",
+	       acpi_device_path(dev), dev->chip_ops->name,
+	       dev->path.i2c.device, config->irq.pin);
+}
+
+static const char *nau8825_acpi_name(struct device *dev)
+{
+	return NAU8825_ACPI_NAME;
+}
+#endif
+
+static struct device_operations nau8825_ops = {
+	.read_resources		  = DEVICE_NOOP,
+	.set_resources		  = DEVICE_NOOP,
+	.enable_resources	  = DEVICE_NOOP,
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+	.acpi_name                = &nau8825_acpi_name,
+	.acpi_fill_ssdt_generator = &nau8825_fill_ssdt,
+#endif
+};
+
+static void nau8825_enable(struct device *dev)
+{
+	dev->ops = &nau8825_ops;
+}
+
+struct chip_operations drivers_i2c_nau8825_ops = {
+	CHIP_NAME("Nuvoton NAU8825 Codec")
+	.enable_dev = &nau8825_enable
+};