dptf: Introduce new paradigm for configuring DPTF parameters

Currently, configuring and reviewing DPTF parameters is difficult
because DPTF tables and methods are defined in static ASL files, and are
littered with #ifdefs which both define parameters and influence
behavior (e.g., whether a method is included or not). This patch train
is an effort to bring DPTF support to our ACPI DSDT/SSDT generation
framework.

This first patch is very minimal, and includes only creation of the
DPTF device (in the DSDT).

BUG=b:143539650
TEST=compiles (later tests get more comprehensive).

Change-Id: I14df9f422c911677aeea25552ac1822a9462c58a
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41883
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/intel/dptf/Kconfig

@@ -0,0 +1,7 @@
+config DRIVERS_INTEL_DPTF
+	bool "Support runtime generation of Intel DPTF ACPI tables"
+	depends on HAVE_ACPI_TABLES
+	default n
+	help
+	   When enabled, entries in the devicetree are used to generate
+	   Intel DPTF Tables at runtime in the SSDT.

src/drivers/intel/dptf/Makefile.inc

@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_INTEL_DPTF) += dptf.c

src/drivers/intel/dptf/chip.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _DRIVERS_INTEL_DPTF_CHIP_H_
+#define _DRIVERS_INTEL_DPTF_CHIP_H_
+
+struct drivers_intel_dptf_config {
+};
+
+#endif /* _DRIVERS_INTEL_DPTF_CHIP_H_ */

src/drivers/intel/dptf/dptf.c

@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <acpi/acpigen.h>
+#include <console/console.h>
+#include <device/device.h>
+#include "chip.h"
+
+static const char *dptf_acpi_name(const struct device *dev)
+{
+	return "DPTF";
+}
+
+/* Add custom tables and methods to SSDT */
+static void dptf_fill_ssdt(const struct device *dev)
+{
+	struct drivers_intel_dptf_config *config = dev->chip_info;
+
+	printk(BIOS_INFO, "\\_SB.DPTF: %s at %s\n", dev->chip_ops->name, dev_path(dev));
+}
+
+/* Add static definitions of DPTF devices into the DSDT */
+static void dptf_inject_dsdt(const struct device *dev)
+{
+	const struct drivers_intel_dptf_config *config;
+
+	config = dev->chip_info;
+	acpigen_write_scope("\\_SB");
+
+	/* Toplevel DPTF device */
+	acpigen_write_device(acpi_device_name(dev));
+	acpigen_write_name("_HID");
+	acpigen_emit_eisaid("INT3400");
+	acpigen_write_name_integer("_UID", 0);
+	dptf_write_STA();
+
+	acpigen_pop_len(); /* DPTF Device */
+	acpigen_pop_len(); /* Scope */
+}
+
+static struct device_operations dptf_ops = {
+	.read_resources		= noop_read_resources,
+	.set_resources		= noop_set_resources,
+	.acpi_name		= dptf_acpi_name,
+	.acpi_fill_ssdt		= dptf_fill_ssdt,
+	.acpi_inject_dsdt	= dptf_inject_dsdt,
+};
+
+static void dptf_enable_dev(struct device *dev)
+{
+	dev->ops = &dptf_ops;
+}
+
+struct chip_operations drivers_intel_dptf_ops = {
+	CHIP_NAME("Intel DPTF")
+	.enable_dev = dptf_enable_dev,
+};