arch/x86/cpu/apollolake/hostbridge.c - platform/external/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2019 Google LLC
  * Copyright (C) 2015 - 2017 Intel Corp.
  * Copyright (C) 2017 - 2019 Siemens AG
  * (Written by Alexandru Gagniuc <alexandrux.gagniuc@intel.com> for Intel Corp.)
  * (Written by Andrey Petrov <andrey.petrov@intel.com> for Intel Corp.)
  *
  * Portions from coreboot soc/intel/apollolake/chip.c
  */

 #define LOG_CATEGORY UCLASS_NORTHBRIDGE

 #include <common.h>
 #include <dm.h>
 #include <dt-structs.h>
 #include <log.h>
 #include <spl.h>
 #include <tables_csum.h>
 #include <acpi/acpi_table.h>
 #include <asm/acpi_nhlt.h>
 #include <asm/intel_pinctrl.h>
 #include <asm/intel_regs.h>
 #include <asm/io.h>
 #include <asm/pci.h>
 #include <asm/arch/acpi.h>
 #include <asm/arch/hostbridge.h>
 #include <asm/arch/systemagent.h>
 #include <dt-bindings/sound/nhlt.h>
 #include <dm/acpi.h>

 enum {
 	PCIEXBAR		= 0x60,
 	PCIEXBAR_LENGTH_256MB	= 0,
 	PCIEXBAR_LENGTH_128MB,
 	PCIEXBAR_LENGTH_64MB,

 	PCIEXBAR_PCIEXBAREN	= 1 << 0,

 	BGSM			= 0xb4,  /* Base GTT Stolen Memory */
 	TSEG			= 0xb8,  /* TSEG base */
 	TOLUD			= 0xbc,
 };

 #if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
 static const struct nhlt_format_config dmic_1ch_formats[] = {
 	/* 48 KHz 16-bits per sample. */
 	{
 		.num_channels = 1,
 		.sample_freq_khz = 48,
 		.container_bits_per_sample = 16,
 		.valid_bits_per_sample = 16,
 		.settings_file = "dmic-1ch-48khz-16b.dat",
 	},
 };

 static const struct nhlt_dmic_array_config dmic_1ch_mic_config = {
 	.tdm_config = {
 		.config_type = NHLT_TDM_MIC_ARRAY,
 	},
 	.array_type = NHLT_MIC_ARRAY_VENDOR_DEFINED,
 };

 static const struct nhlt_endp_descriptor dmic_1ch_descriptors[] = {
 	{
 		.link = NHLT_LINK_PDM,
 		.device = NHLT_PDM_DEV,
 		.direction = NHLT_DIR_CAPTURE,
 		.vid = NHLT_VID,
 		.did = NHLT_DID_DMIC,
 		.cfg = &dmic_1ch_mic_config,
 		.cfg_size = sizeof(dmic_1ch_mic_config),
 		.formats = dmic_1ch_formats,
 		.num_formats = ARRAY_SIZE(dmic_1ch_formats),
 	},
 };

 static const struct nhlt_format_config dmic_2ch_formats[] = {
 	/* 48 KHz 16-bits per sample. */
 	{
 		.num_channels = 2,
 		.sample_freq_khz = 48,
 		.container_bits_per_sample = 16,
 		.valid_bits_per_sample = 16,
 		.settings_file = "dmic-2ch-48khz-16b.dat",
 	},
 };

 static const struct nhlt_dmic_array_config dmic_2ch_mic_config = {
 	.tdm_config = {
 		.config_type = NHLT_TDM_MIC_ARRAY,
 	},
 	.array_type = NHLT_MIC_ARRAY_2CH_SMALL,
 };

 static const struct nhlt_endp_descriptor dmic_2ch_descriptors[] = {
 	{
 		.link = NHLT_LINK_PDM,
 		.device = NHLT_PDM_DEV,
 		.direction = NHLT_DIR_CAPTURE,
 		.vid = NHLT_VID,
 		.did = NHLT_DID_DMIC,
 		.cfg = &dmic_2ch_mic_config,
 		.cfg_size = sizeof(dmic_2ch_mic_config),
 		.formats = dmic_2ch_formats,
 		.num_formats = ARRAY_SIZE(dmic_2ch_formats),
 	},
 };

 static const struct nhlt_format_config dmic_4ch_formats[] = {
 	/* 48 KHz 16-bits per sample. */
 	{
 		.num_channels = 4,
 		.sample_freq_khz = 48,
 		.container_bits_per_sample = 16,
 		.valid_bits_per_sample = 16,
 		.settings_file = "dmic-4ch-48khz-16b.dat",
 	},
 };

 static const struct nhlt_dmic_array_config dmic_4ch_mic_config = {
 	.tdm_config = {
 		.config_type = NHLT_TDM_MIC_ARRAY,
 	},
 	.array_type = NHLT_MIC_ARRAY_4CH_L_SHAPED,
 };

 static const struct nhlt_endp_descriptor dmic_4ch_descriptors[] = {
 	{
 		.link = NHLT_LINK_PDM,
 		.device = NHLT_PDM_DEV,
 		.direction = NHLT_DIR_CAPTURE,
 		.vid = NHLT_VID,
 		.did = NHLT_DID_DMIC,
 		.cfg = &dmic_4ch_mic_config,
 		.cfg_size = sizeof(dmic_4ch_mic_config),
 		.formats = dmic_4ch_formats,
 		.num_formats = ARRAY_SIZE(dmic_4ch_formats),
 	},
 };
 #endif

 static int apl_hostbridge_early_init_pinctrl(struct udevice *dev)
 {
 	struct apl_hostbridge_plat *plat = dev_get_plat(dev);
 	struct udevice *pinctrl;
 	int ret;

 	ret = uclass_first_device_err(UCLASS_PINCTRL, &pinctrl);
 	if (ret)
 		return log_msg_ret("no hostbridge pinctrl", ret);

 	return pinctrl_config_pads(pinctrl, plat->early_pads,
 				   plat->early_pads_count);
 }

 static int apl_hostbridge_early_init(struct udevice *dev)
 {
 	struct apl_hostbridge_plat *plat = dev_get_plat(dev);
 	u32 region_size;
 	ulong base;
 	u32 reg;
 	int ret;

 	/* Set up the MCHBAR */
 	pci_x86_read_config(plat->bdf, MCHBAR, &base, PCI_SIZE_32);
 	base = MCH_BASE_ADDRESS;
 	pci_x86_write_config(plat->bdf, MCHBAR, base | 1, PCI_SIZE_32);

 	/*
 	 * The PCIEXBAR is assumed to live in the memory mapped IO space under
 	 * 4GiB
 	 */
 	pci_x86_write_config(plat->bdf, PCIEXBAR + 4, 0, PCI_SIZE_32);

 	switch (plat->pciex_region_size >> 20) {
 	default:
 	case 256:
 		region_size = PCIEXBAR_LENGTH_256MB;
 		break;
 	case 128:
 		region_size = PCIEXBAR_LENGTH_128MB;
 		break;
 	case 64:
 		region_size = PCIEXBAR_LENGTH_64MB;
 		break;
 	}

 	reg = CONFIG_MMCONF_BASE_ADDRESS | (region_size << 1)
 				| PCIEXBAR_PCIEXBAREN;
 	pci_x86_write_config(plat->bdf, PCIEXBAR, reg, PCI_SIZE_32);

 	/*
 	 * TSEG defines the base of SMM range. BIOS determines the base
 	 * of TSEG memory which must be at or below Graphics base of GTT
 	 * Stolen memory, hence its better to clear TSEG register early
 	 * to avoid power on default non-zero value (if any).
 	 */
 	pci_x86_write_config(plat->bdf, TSEG, 0, PCI_SIZE_32);

 	ret = apl_hostbridge_early_init_pinctrl(dev);
 	if (ret)
 		return log_msg_ret("pinctrl", ret);

 	return 0;
 }

 static int apl_hostbridge_of_to_plat(struct udevice *dev)
 {
 	struct apl_hostbridge_plat *plat = dev_get_plat(dev);
 	struct udevice *pinctrl;
 	int ret;

 	/*
 	 * The host bridge holds the early pad data needed to get through TPL.
 	 * This is a small amount of data, enough to fit in TPL, so we keep it
 	 * separate from the full pad data, stored in the fsp-s subnode. That
 	 * subnode is not present in TPL, to save space.
 	 */
 	ret = uclass_first_device_err(UCLASS_PINCTRL, &pinctrl);
 	if (ret)
 		return log_msg_ret("no hostbridge PINCTRL", ret);
 #if CONFIG_IS_ENABLED(OF_REAL)
 	int root;

 	/* Get length of PCI Express Region */
 	plat->pciex_region_size = dev_read_u32_default(dev, "pciex-region-size",
 						       256 << 20);

 	root = pci_get_devfn(dev);
 	if (root < 0)
 		return log_msg_ret("Cannot get host-bridge PCI address", root);
 	plat->bdf = root;

 	ret = pinctrl_read_pads(pinctrl, dev_ofnode(dev), "early-pads",
 				&plat->early_pads, &plat->early_pads_count);
 	if (ret)
 		return log_msg_ret("early-pads", ret);
 #else
 	struct dtd_intel_apl_hostbridge *dtplat = &plat->dtplat;
 	int size;

 	plat->pciex_region_size = dtplat->pciex_region_size;
 	plat->bdf = pci_ofplat_get_devfn(dtplat->reg[0]);

 	/* Assume that if everything is 0, it is empty */
 	plat->early_pads = dtplat->early_pads;
 	size = ARRAY_SIZE(dtplat->early_pads);
 	plat->early_pads_count = pinctrl_count_pads(pinctrl, plat->early_pads,
 						    size);

 #endif

 	return 0;
 }

 static int apl_hostbridge_probe(struct udevice *dev)
 {
 	if (spl_phase() == PHASE_TPL)
 		return apl_hostbridge_early_init(dev);

 	return 0;
 }

 static int apl_acpi_hb_get_name(const struct udevice *dev, char *out_name)
 {
 	return acpi_copy_name(out_name, "RHUB");
 }

 #if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
 static int apl_acpi_hb_write_tables(const struct udevice *dev,
 				    struct acpi_ctx *ctx)
 {
 	struct acpi_table_header *header;
 	struct acpi_dmar *dmar;
 	u32 val;

 	/*
 	 * Create DMAR table only if virtualization is enabled. Due to some
 	 * constraints on Apollo Lake SoC (some stepping affected), VTD could
 	 * not be enabled together with IPU. Doing so will override and disable
 	 * VTD while leaving CAPID0_A still reporting that VTD is available.
 	 * As in this case FSP will lock VTD to disabled state, we need to make
 	 * sure that DMAR table generation only happens when at least DEFVTBAR
 	 * is enabled. Otherwise the DMAR header will be generated while the
 	 * content of the table will be missing.
 	 */
 	dm_pci_read_config32(dev, CAPID0_A, &val);
 	if ((val & VTD_DISABLE) ||
 	    !(readl(MCHBAR_REG(DEFVTBAR)) & VTBAR_ENABLED))
 		return 0;

 	log_debug("ACPI:    * DMAR\n");
 	dmar = (struct acpi_dmar *)ctx->current;
 	header = &dmar->header;
 	acpi_create_dmar(dmar, DMAR_INTR_REMAP);
 	ctx->current += sizeof(struct acpi_dmar);
 	apl_acpi_fill_dmar(ctx);

 	/* (Re)calculate length and checksum */
 	header->length = ctx->current - (void *)dmar;
 	header->checksum = table_compute_checksum((void *)dmar, header->length);

 	acpi_align(ctx);
 	acpi_add_table(ctx, dmar);

 	return 0;
 }

 static int apl_acpi_setup_nhlt(const struct udevice *dev, struct acpi_ctx *ctx)
 {
 	struct nhlt *nhlt = ctx->nhlt;
 	u32 channels;
 	ofnode node;

 	node = ofnode_find_subnode(dev_ofnode(dev), "nhlt");
 	if (ofnode_read_u32(node, "intel,dmic-channels", &channels))
 		return log_msg_ret("channels", -EINVAL);
 	switch (channels) {
 	case 1:
 		return nhlt_add_endpoints(nhlt, dmic_1ch_descriptors,
 					  ARRAY_SIZE(dmic_1ch_descriptors));
 	case 2:
 		return nhlt_add_endpoints(nhlt, dmic_2ch_descriptors,
 					  ARRAY_SIZE(dmic_2ch_descriptors));
 	case 4:
 		return nhlt_add_endpoints(nhlt, dmic_4ch_descriptors,
 					  ARRAY_SIZE(dmic_4ch_descriptors));
 	}

 	return log_msg_ret("channels", -EINVAL);
 }
 #endif

 static int apl_hostbridge_remove(struct udevice *dev)
 {
 	/*
 	 * TODO(sjg@chromium.org): Consider adding code from coreboot's
 	 * platform_fsp_notify_status()
 	 */

 	return 0;
 }

 static ulong sa_read_reg(struct udevice *dev, int reg)
 {
 	u32 val;

 	/* All regions concerned for have 1 MiB alignment */
 	dm_pci_read_config32(dev, BGSM, &val);

 	return ALIGN_DOWN(val, 1 << 20);
 }

 ulong sa_get_tolud_base(struct udevice *dev)
 {
 	return sa_read_reg(dev, TOLUD);
 }

 ulong sa_get_gsm_base(struct udevice *dev)
 {
 	return sa_read_reg(dev, BGSM);
 }

 ulong sa_get_tseg_base(struct udevice *dev)
 {
 	return sa_read_reg(dev, TSEG);
 }

 struct acpi_ops apl_hostbridge_acpi_ops = {
 	.get_name	= apl_acpi_hb_get_name,
 #if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
 	.write_tables	= apl_acpi_hb_write_tables,
 	.setup_nhlt	= apl_acpi_setup_nhlt,
 #endif
 };

 #if CONFIG_IS_ENABLED(OF_REAL)
 static const struct udevice_id apl_hostbridge_ids[] = {
 	{ .compatible = "intel,apl-hostbridge" },
 	{ }
 };
 #endif

 U_BOOT_DRIVER(intel_apl_hostbridge) = {
 	.name		= "intel_apl_hostbridge",
 	.id		= UCLASS_NORTHBRIDGE,
 	.of_match	= of_match_ptr(apl_hostbridge_ids),
 	.of_to_plat = apl_hostbridge_of_to_plat,
 	.probe		= apl_hostbridge_probe,
 	.remove		= apl_hostbridge_remove,
 	.plat_auto	= sizeof(struct apl_hostbridge_plat),
 	ACPI_OPS_PTR(&apl_hostbridge_acpi_ops)
 	.flags		= DM_FLAG_OS_PREPARE,
 };
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright 2019 Google LLC
	* Copyright (C) 2015 - 2017 Intel Corp.
	* Copyright (C) 2017 - 2019 Siemens AG
	* (Written by Alexandru Gagniuc <alexandrux.gagniuc@intel.com> for Intel Corp.)
	* (Written by Andrey Petrov <andrey.petrov@intel.com> for Intel Corp.)
	*
	* Portions from coreboot soc/intel/apollolake/chip.c
	*/

	#define LOG_CATEGORY UCLASS_NORTHBRIDGE

	#include <common.h>
	#include <dm.h>
	#include <dt-structs.h>
	#include <log.h>
	#include <spl.h>
	#include <tables_csum.h>
	#include <acpi/acpi_table.h>
	#include <asm/acpi_nhlt.h>
	#include <asm/intel_pinctrl.h>
	#include <asm/intel_regs.h>
	#include <asm/io.h>
	#include <asm/pci.h>
	#include <asm/arch/acpi.h>
	#include <asm/arch/hostbridge.h>
	#include <asm/arch/systemagent.h>
	#include <dt-bindings/sound/nhlt.h>
	#include <dm/acpi.h>

	enum {
	PCIEXBAR = 0x60,
	PCIEXBAR_LENGTH_256MB = 0,
	PCIEXBAR_LENGTH_128MB,
	PCIEXBAR_LENGTH_64MB,

	PCIEXBAR_PCIEXBAREN = 1 << 0,

	BGSM = 0xb4, /* Base GTT Stolen Memory */
	TSEG = 0xb8, /* TSEG base */
	TOLUD = 0xbc,
	};

	#if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
	static const struct nhlt_format_config dmic_1ch_formats[] = {
	/* 48 KHz 16-bits per sample. */
	{
	.num_channels = 1,
	.sample_freq_khz = 48,
	.container_bits_per_sample = 16,
	.valid_bits_per_sample = 16,
	.settings_file = "dmic-1ch-48khz-16b.dat",
	},
	};

	static const struct nhlt_dmic_array_config dmic_1ch_mic_config = {
	.tdm_config = {
	.config_type = NHLT_TDM_MIC_ARRAY,
	},
	.array_type = NHLT_MIC_ARRAY_VENDOR_DEFINED,
	};

	static const struct nhlt_endp_descriptor dmic_1ch_descriptors[] = {
	{
	.link = NHLT_LINK_PDM,
	.device = NHLT_PDM_DEV,
	.direction = NHLT_DIR_CAPTURE,
	.vid = NHLT_VID,
	.did = NHLT_DID_DMIC,
	.cfg = &dmic_1ch_mic_config,
	.cfg_size = sizeof(dmic_1ch_mic_config),
	.formats = dmic_1ch_formats,
	.num_formats = ARRAY_SIZE(dmic_1ch_formats),
	},
	};

	static const struct nhlt_format_config dmic_2ch_formats[] = {
	/* 48 KHz 16-bits per sample. */
	{
	.num_channels = 2,
	.sample_freq_khz = 48,
	.container_bits_per_sample = 16,
	.valid_bits_per_sample = 16,
	.settings_file = "dmic-2ch-48khz-16b.dat",
	},
	};

	static const struct nhlt_dmic_array_config dmic_2ch_mic_config = {
	.tdm_config = {
	.config_type = NHLT_TDM_MIC_ARRAY,
	},
	.array_type = NHLT_MIC_ARRAY_2CH_SMALL,
	};

	static const struct nhlt_endp_descriptor dmic_2ch_descriptors[] = {
	{
	.link = NHLT_LINK_PDM,
	.device = NHLT_PDM_DEV,
	.direction = NHLT_DIR_CAPTURE,
	.vid = NHLT_VID,
	.did = NHLT_DID_DMIC,
	.cfg = &dmic_2ch_mic_config,
	.cfg_size = sizeof(dmic_2ch_mic_config),
	.formats = dmic_2ch_formats,
	.num_formats = ARRAY_SIZE(dmic_2ch_formats),
	},
	};

	static const struct nhlt_format_config dmic_4ch_formats[] = {
	/* 48 KHz 16-bits per sample. */
	{
	.num_channels = 4,
	.sample_freq_khz = 48,
	.container_bits_per_sample = 16,
	.valid_bits_per_sample = 16,
	.settings_file = "dmic-4ch-48khz-16b.dat",
	},
	};

	static const struct nhlt_dmic_array_config dmic_4ch_mic_config = {
	.tdm_config = {
	.config_type = NHLT_TDM_MIC_ARRAY,
	},
	.array_type = NHLT_MIC_ARRAY_4CH_L_SHAPED,
	};

	static const struct nhlt_endp_descriptor dmic_4ch_descriptors[] = {
	{
	.link = NHLT_LINK_PDM,
	.device = NHLT_PDM_DEV,
	.direction = NHLT_DIR_CAPTURE,
	.vid = NHLT_VID,
	.did = NHLT_DID_DMIC,
	.cfg = &dmic_4ch_mic_config,
	.cfg_size = sizeof(dmic_4ch_mic_config),
	.formats = dmic_4ch_formats,
	.num_formats = ARRAY_SIZE(dmic_4ch_formats),
	},
	};
	#endif

	static int apl_hostbridge_early_init_pinctrl(struct udevice *dev)
	{
	struct apl_hostbridge_plat *plat = dev_get_plat(dev);
	struct udevice *pinctrl;
	int ret;

	ret = uclass_first_device_err(UCLASS_PINCTRL, &pinctrl);
	if (ret)
	return log_msg_ret("no hostbridge pinctrl", ret);

	return pinctrl_config_pads(pinctrl, plat->early_pads,
	plat->early_pads_count);
	}

	static int apl_hostbridge_early_init(struct udevice *dev)
	{
	struct apl_hostbridge_plat *plat = dev_get_plat(dev);
	u32 region_size;
	ulong base;
	u32 reg;
	int ret;

	/* Set up the MCHBAR */
	pci_x86_read_config(plat->bdf, MCHBAR, &base, PCI_SIZE_32);
	base = MCH_BASE_ADDRESS;
	pci_x86_write_config(plat->bdf, MCHBAR, base \| 1, PCI_SIZE_32);

	/*
	* The PCIEXBAR is assumed to live in the memory mapped IO space under
	* 4GiB
	*/
	pci_x86_write_config(plat->bdf, PCIEXBAR + 4, 0, PCI_SIZE_32);

	switch (plat->pciex_region_size >> 20) {
	default:
	case 256:
	region_size = PCIEXBAR_LENGTH_256MB;
	break;
	case 128:
	region_size = PCIEXBAR_LENGTH_128MB;
	break;
	case 64:
	region_size = PCIEXBAR_LENGTH_64MB;
	break;
	}

	reg = CONFIG_MMCONF_BASE_ADDRESS \| (region_size << 1)
	\| PCIEXBAR_PCIEXBAREN;
	pci_x86_write_config(plat->bdf, PCIEXBAR, reg, PCI_SIZE_32);

	/*
	* TSEG defines the base of SMM range. BIOS determines the base
	* of TSEG memory which must be at or below Graphics base of GTT
	* Stolen memory, hence its better to clear TSEG register early
	* to avoid power on default non-zero value (if any).
	*/
	pci_x86_write_config(plat->bdf, TSEG, 0, PCI_SIZE_32);

	ret = apl_hostbridge_early_init_pinctrl(dev);
	if (ret)
	return log_msg_ret("pinctrl", ret);

	return 0;
	}

	static int apl_hostbridge_of_to_plat(struct udevice *dev)
	{
	struct apl_hostbridge_plat *plat = dev_get_plat(dev);
	struct udevice *pinctrl;
	int ret;

	/*
	* The host bridge holds the early pad data needed to get through TPL.
	* This is a small amount of data, enough to fit in TPL, so we keep it
	* separate from the full pad data, stored in the fsp-s subnode. That
	* subnode is not present in TPL, to save space.
	*/
	ret = uclass_first_device_err(UCLASS_PINCTRL, &pinctrl);
	if (ret)
	return log_msg_ret("no hostbridge PINCTRL", ret);
	#if CONFIG_IS_ENABLED(OF_REAL)
	int root;

	/* Get length of PCI Express Region */
	plat->pciex_region_size = dev_read_u32_default(dev, "pciex-region-size",
	256 << 20);

	root = pci_get_devfn(dev);
	if (root < 0)
	return log_msg_ret("Cannot get host-bridge PCI address", root);
	plat->bdf = root;

	ret = pinctrl_read_pads(pinctrl, dev_ofnode(dev), "early-pads",
	&plat->early_pads, &plat->early_pads_count);
	if (ret)
	return log_msg_ret("early-pads", ret);
	#else
	struct dtd_intel_apl_hostbridge *dtplat = &plat->dtplat;
	int size;

	plat->pciex_region_size = dtplat->pciex_region_size;
	plat->bdf = pci_ofplat_get_devfn(dtplat->reg[0]);

	/* Assume that if everything is 0, it is empty */
	plat->early_pads = dtplat->early_pads;
	size = ARRAY_SIZE(dtplat->early_pads);
	plat->early_pads_count = pinctrl_count_pads(pinctrl, plat->early_pads,
	size);

	#endif

	return 0;
	}

	static int apl_hostbridge_probe(struct udevice *dev)
	{
	if (spl_phase() == PHASE_TPL)
	return apl_hostbridge_early_init(dev);

	return 0;
	}

	static int apl_acpi_hb_get_name(const struct udevice dev, char out_name)
	{
	return acpi_copy_name(out_name, "RHUB");
	}

	#if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
	static int apl_acpi_hb_write_tables(const struct udevice *dev,
	struct acpi_ctx *ctx)
	{
	struct acpi_table_header *header;
	struct acpi_dmar *dmar;
	u32 val;

	/*
	* Create DMAR table only if virtualization is enabled. Due to some
	* constraints on Apollo Lake SoC (some stepping affected), VTD could
	* not be enabled together with IPU. Doing so will override and disable
	* VTD while leaving CAPID0_A still reporting that VTD is available.
	* As in this case FSP will lock VTD to disabled state, we need to make
	* sure that DMAR table generation only happens when at least DEFVTBAR
	* is enabled. Otherwise the DMAR header will be generated while the
	* content of the table will be missing.
	*/
	dm_pci_read_config32(dev, CAPID0_A, &val);
	if ((val & VTD_DISABLE) \|\|
	!(readl(MCHBAR_REG(DEFVTBAR)) & VTBAR_ENABLED))
	return 0;

	log_debug("ACPI: * DMAR\n");
	dmar = (struct acpi_dmar *)ctx->current;
	header = &dmar->header;
	acpi_create_dmar(dmar, DMAR_INTR_REMAP);
	ctx->current += sizeof(struct acpi_dmar);
	apl_acpi_fill_dmar(ctx);

	/* (Re)calculate length and checksum */
	header->length = ctx->current - (void *)dmar;
	header->checksum = table_compute_checksum((void *)dmar, header->length);

	acpi_align(ctx);
	acpi_add_table(ctx, dmar);

	return 0;
	}

	static int apl_acpi_setup_nhlt(const struct udevice dev, struct acpi_ctx ctx)
	{
	struct nhlt *nhlt = ctx->nhlt;
	u32 channels;
	ofnode node;

	node = ofnode_find_subnode(dev_ofnode(dev), "nhlt");
	if (ofnode_read_u32(node, "intel,dmic-channels", &channels))
	return log_msg_ret("channels", -EINVAL);
	switch (channels) {
	case 1:
	return nhlt_add_endpoints(nhlt, dmic_1ch_descriptors,
	ARRAY_SIZE(dmic_1ch_descriptors));
	case 2:
	return nhlt_add_endpoints(nhlt, dmic_2ch_descriptors,
	ARRAY_SIZE(dmic_2ch_descriptors));
	case 4:
	return nhlt_add_endpoints(nhlt, dmic_4ch_descriptors,
	ARRAY_SIZE(dmic_4ch_descriptors));
	}

	return log_msg_ret("channels", -EINVAL);
	}
	#endif

	static int apl_hostbridge_remove(struct udevice *dev)
	{
	/*
	* TODO(sjg@chromium.org): Consider adding code from coreboot's
	* platform_fsp_notify_status()
	*/

	return 0;
	}

	static ulong sa_read_reg(struct udevice *dev, int reg)
	{
	u32 val;

	/* All regions concerned for have 1 MiB alignment */
	dm_pci_read_config32(dev, BGSM, &val);

	return ALIGN_DOWN(val, 1 << 20);
	}

	ulong sa_get_tolud_base(struct udevice *dev)
	{
	return sa_read_reg(dev, TOLUD);
	}

	ulong sa_get_gsm_base(struct udevice *dev)
	{
	return sa_read_reg(dev, BGSM);
	}

	ulong sa_get_tseg_base(struct udevice *dev)
	{
	return sa_read_reg(dev, TSEG);
	}

	struct acpi_ops apl_hostbridge_acpi_ops = {
	.get_name = apl_acpi_hb_get_name,
	#if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
	.write_tables = apl_acpi_hb_write_tables,
	.setup_nhlt = apl_acpi_setup_nhlt,
	#endif
	};

	#if CONFIG_IS_ENABLED(OF_REAL)
	static const struct udevice_id apl_hostbridge_ids[] = {
	{ .compatible = "intel,apl-hostbridge" },
	{ }
	};
	#endif

	U_BOOT_DRIVER(intel_apl_hostbridge) = {
	.name = "intel_apl_hostbridge",
	.id = UCLASS_NORTHBRIDGE,
	.of_match = of_match_ptr(apl_hostbridge_ids),
	.of_to_plat = apl_hostbridge_of_to_plat,
	.probe = apl_hostbridge_probe,
	.remove = apl_hostbridge_remove,
	.plat_auto = sizeof(struct apl_hostbridge_plat),
	ACPI_OPS_PTR(&apl_hostbridge_acpi_ops)
	.flags = DM_FLAG_OS_PREPARE,
	};