4 files changed, 143 insertions, 0 deletions
diff --git a/src/drivers/i2c/generic/Kconfig b/src/drivers/i2c/generic/Kconfig
new file mode 100644
index 0000000000..a4c01048aa
--- /dev/null
+++ b/src/drivers/i2c/generic/Kconfig
@@ -0,0 +1,2 @@
+config DRIVERS_I2C_GENERIC
+	bool
diff --git a/src/drivers/i2c/generic/Makefile.inc b/src/drivers/i2c/generic/Makefile.inc
new file mode 100644
index 0000000000..86cbc7bdc3
--- /dev/null
+++ b/src/drivers/i2c/generic/Makefile.inc
@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_I2C_GENERIC) += generic.c
diff --git a/src/drivers/i2c/generic/chip.h b/src/drivers/i2c/generic/chip.h
new file mode 100644
index 0000000000..84657d5241
--- /dev/null
+++ b/src/drivers/i2c/generic/chip.h
@@ -0,0 +1,16 @@
+#include <arch/acpi_device.h>
+#include <device/i2c.h>
+
+struct drivers_i2c_generic_config {
+	const char *hid;	/* ACPI _HID (required) */
+	const char *name;	/* ACPI Device Name */
+	const char *desc;	/* Device Description */
+	unsigned uid;		/* ACPI _UID */
+	enum i2c_speed speed;	/* Bus speed in Hz, default is I2C_SPEED_FAST */
+	unsigned wake;		/* Wake GPE */
+	struct acpi_irq irq;	/* Interrupt */
+
+	/* GPIO used to indicate if this device is present */
+	unsigned device_present_gpio;
+	unsigned device_present_gpio_invert;
+};
diff --git a/src/drivers/i2c/generic/generic.c b/src/drivers/i2c/generic/generic.c
new file mode 100644
index 0000000000..1c10b0e3cf
--- /dev/null
+++ b/src/drivers/i2c/generic/generic.c
@@ -0,0 +1,124 @@
+/*
+ * 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_device.h>
+#include <arch/acpigen.h>
+#include <console/console.h>
+#include <device/i2c.h>
+#include <device/device.h>
+#include <device/path.h>
+#include <gpio.h>
+#include <stdint.h>
+#include <string.h>
+#include "chip.h"
+
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+static void i2c_generic_fill_ssdt(struct device *dev)
+{
+	struct drivers_i2c_generic_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->hid) {
+		printk(BIOS_ERR, "%s: ERROR: HID required\n", dev_path(dev));
+		return;
+	}
+
+	/* Device */
+	acpigen_write_scope(scope);
+	acpigen_write_device(acpi_device_name(dev));
+	acpigen_write_name_string("_HID", config->hid);
+	acpigen_write_name_integer("_UID", config->uid);
+	acpigen_write_name_string("_DDN", config->desc);
+	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();
+
+	/* Wake capabilities */
+	if (config->wake) {
+		acpigen_write_name_integer("_S0W", 4);
+		acpigen_write_PRW(config->wake, 3);
+	}
+
+	acpigen_pop_len(); /* Device */
+	acpigen_pop_len(); /* Scope */
+
+	printk(BIOS_INFO, "%s: %s at %s\n", acpi_device_path(dev),
+	       config->desc ? : dev->chip_ops->name, dev_path(dev));
+}
+
+/* Use name specified in config or build one from I2C address */
+static const char *i2c_generic_acpi_name(struct device *dev)
+{
+	struct drivers_i2c_generic_config *config = dev->chip_info;
+	static char name[5];
+
+	if (config->name)
+		return name;
+
+	snprintf(name, sizeof(name), "D%03.3X", dev->path.i2c.device);
+	name[4] = '\0';
+	return name;
+}
+#endif
+
+static struct device_operations i2c_generic_ops = {
+	.read_resources		  = DEVICE_NOOP,
+	.set_resources		  = DEVICE_NOOP,
+	.enable_resources	  = DEVICE_NOOP,
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+	.acpi_name		  = &i2c_generic_acpi_name,
+	.acpi_fill_ssdt_generator = &i2c_generic_fill_ssdt,
+#endif
+};
+
+static void i2c_generic_enable(struct device *dev)
+{
+	struct drivers_i2c_generic_config *config = dev->chip_info;
+
+	/* Check if device is present by reading GPIO */
+	if (config->device_present_gpio) {
+		int present = gpio_get(config->device_present_gpio);
+		present ^= config->device_present_gpio_invert;
+
+		printk(BIOS_INFO, "%s is %spresent\n",
+		       dev->chip_ops->name, present ? "" : "not ");
+
+		if (!present) {
+			dev->enabled = 0;
+			return;
+		}
+	}
+
+	dev->ops = &i2c_generic_ops;
+}
+
+struct chip_operations drivers_i2c_generic_ops = {
+	CHIP_NAME("I2C Device")
+	.enable_dev = &i2c_generic_enable
+};