drivers/i2c: Add a driver for Semtech SX9310

This adds a new driver for the SX9310 proximity detector device.

The purpose of this is to enable the device's calibration information
to be stored in firmware, and then transferred over to the kernel
via ACPI.

This device has more than 10 individual configuration parameters,
so they would not fit in the generic driver's properties table.

Change-Id: Id8c434eec9fe2da731e142442503a12e88db2236
Signed-off-by: Enrico Granata <egranata@chromium.org>
Reviewed-on: https://review.coreboot.org/27173
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/drivers/i2c/sx9310/sx9310.c b/src/drivers/i2c/sx9310/sx9310.c
new file mode 100644
index 0000000..7da87c4
--- /dev/null
+++ b/src/drivers/i2c/sx9310/sx9310.c
@@ -0,0 +1,107 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Google LLC
+ *
+ * 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 <device/i2c_simple.h>
+#include <device/device.h>
+#include <device/path.h>
+#include <stdint.h>
+#include <string.h>
+#include "chip.h"
+
+#define I2C_SX9310_ACPI_ID	"SX9310"
+#define I2C_SX9310_ACPI_NAME	"Semtech SX9310"
+
+#define REGISTER(NAME) acpi_dp_add_integer(dsd, \
+					I2C_SX9310_ACPI_ID "," #NAME, \
+					config->NAME)
+
+static void i2c_sx9310_fill_ssdt(struct device *dev)
+{
+	struct drivers_i2c_sx9310_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->speed ? : I2C_SPEED_FAST,
+		.resource = scope,
+	};
+	struct acpi_dp *dsd;
+
+	if (!dev->enabled || !scope || !config)
+		return;
+
+	/* Device */
+	acpigen_write_scope(scope);
+	acpigen_write_device(acpi_device_name(dev));
+	acpigen_write_name_string("_HID", I2C_SX9310_ACPI_ID);
+	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();
+
+	/* DSD */
+	dsd = acpi_dp_new_table("_DSD");
+#include "registers.h"
+	acpi_dp_write(dsd);
+
+	acpigen_pop_len(); /* Device */
+	acpigen_pop_len(); /* Scope */
+}
+
+#undef REGISTER
+
+static const char *i2c_sx9310_acpi_name(const struct device *dev)
+{
+	static char name[5];
+
+	snprintf(name, sizeof(name), "D%03.3X", dev->path.i2c.device);
+	return name;
+}
+
+static struct device_operations i2c_sx9310_ops = {
+	.read_resources		  = DEVICE_NOOP,
+	.set_resources		  = DEVICE_NOOP,
+	.enable_resources	  = DEVICE_NOOP,
+	.acpi_name		  = &i2c_sx9310_acpi_name,
+	.acpi_fill_ssdt_generator = &i2c_sx9310_fill_ssdt,
+};
+
+static void i2c_sx9310_enable(struct device *dev)
+{
+	struct drivers_i2c_sx9310_config *config = dev->chip_info;
+
+	if (!config) {
+		dev->enabled = 0;
+		return;
+	}
+
+	dev->ops = &i2c_sx9310_ops;
+
+	if (config->desc)
+		dev->name = config->desc;
+}
+
+struct chip_operations drivers_i2c_sx9310_ops = {
+	CHIP_NAME(I2C_SX9310_ACPI_NAME)
+	.enable_dev = &i2c_sx9310_enable
+};