driver/intel/ish: add ish chip driver support

We want to be able to specify the firmware variant suffix
in the devicetree.cb configuration for particular firmware
builds. This driver allows us to specify the firmware_variant
property in the device tree and have it populate a _DST table
in the SSDT ACPI table for the ISH device, thus making the
suffix available to the kernel (See crrev.com/c/1433482 for kernel
change that uses the value)

BUG=b:122722008
TEST=decompile DDST table and verify that new firmware-variant value
is present. Also verfied that kernel can access this new field using
the shim loader kernel CLs

Change-Id: Id8be986185282521aee574027503eaf8968e1508
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31682
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/drivers/intel/ish/Kconfig

@@ -0,0 +1,5 @@
+config DRIVERS_INTEL_ISH
+	bool
+	help
+	   When enabled, chip driver/intel/ish will publish information to the
+	   SSDT _DSD table for the ISH device.

src/drivers/intel/ish/Makefile.inc

@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_INTEL_ISH) += ish.c

src/drivers/intel/ish/chip.h

@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2019 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.
+ */
+
+/*
+ * Intel Integrated Sensor Hub (ISH)
+ */
+struct drivers_intel_ish_config {
+	/* Firmware name used by kernel for loading ISH firmware */
+	const char *firmware_name;
+};

src/drivers/intel/ish/ish.c

@@ -0,0 +1,81 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2019 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 <console/console.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include "chip.h"
+
+static void ish_fill_ssdt_generator(struct device *dev)
+{
+	struct drivers_intel_ish_config *config = dev->chip_info;
+	struct device *root = dev->bus->dev;
+	struct acpi_dp *dsd;
+
+	if (!dev->enabled || !config || !config->firmware_name)
+		return;
+
+	acpigen_write_scope(acpi_device_path(root));
+
+	dsd = acpi_dp_new_table("_DSD");
+	acpi_dp_add_string(dsd, "firmware-name", config->firmware_name);
+	acpi_dp_write(dsd);
+
+	acpigen_pop_len();	/* Scope */
+
+	printk(BIOS_INFO, "%s: Set firmware-name: %s\n",
+	       acpi_device_path(root), config->firmware_name);
+}
+
+static struct device_operations intel_ish_ops = {
+	.read_resources			= DEVICE_NOOP,
+	.set_resources			= DEVICE_NOOP,
+	.enable_resources		= DEVICE_NOOP,
+	.acpi_fill_ssdt_generator	= ish_fill_ssdt_generator,
+};
+
+static void intel_ish_enable(struct device *dev)
+{
+	/* This dev is a generic device that is a child to the ISH PCI device */
+	dev->ops = &intel_ish_ops;
+}
+
+/* Copy of default_pci_ops_dev with scan_bus addition */
+static const struct device_operations pci_ish_device_ops = {
+	.read_resources   = pci_dev_read_resources,
+	.set_resources    = pci_dev_set_resources,
+	.enable_resources = pci_dev_enable_resources,
+	.init             = pci_dev_init,
+	.scan_bus         = &scan_generic_bus, /* Non-default */
+	.ops_pci          = &pci_dev_ops_pci,
+};
+
+static const unsigned short pci_device_ids[] = {
+	PCI_DEVICE_ID_INTEL_CNL_ISHB,
+	0
+};
+
+static const struct pci_driver ish_intel_driver __pci_driver = {
+	.ops		= &pci_ish_device_ops,
+	.vendor		= PCI_VENDOR_ID_INTEL,
+	.devices	= pci_device_ids,
+};
+
+struct chip_operations drivers_intel_ish_ops = {
+	CHIP_NAME("Intel ISH Chip")
+	.enable_dev	= intel_ish_enable,
+};

src/include/device/pci_ids.h

@@ -2091,6 +2091,7 @@
 #define PCI_DEVICE_ID_INTEL_80960_RP	0x1960
 #define PCI_DEVICE_ID_INTEL_82437VX	0x7030
 #define PCI_DEVICE_ID_INTEL_82439TX	0x7100
+#define PCI_DEVICE_ID_INTEL_CNL_ISHB	0x9dfc
 
 /* Intel 82371FB (PIIX) */
 #define PCI_DEVICE_ID_INTEL_82371FB_ISA		0x122e