Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1342 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
new file mode 100644
index 000000000..ded6c5c17
--- /dev/null
+++ b/drivers/acpi/acpi_lpss.c
@@ -0,0 +1,1342 @@
+/*
+ * ACPI support for Intel Lynxpoint LPSS.
+ *
+ * Copyright (C) 2013, Intel Corporation
+ * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/clk-lpss.h>
+#include <linux/platform_data/x86/pmc_atom.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+#include <linux/suspend.h>
+#include <linux/delay.h>
+
+#include "internal.h"
+
+ACPI_MODULE_NAME("acpi_lpss");
+
+#ifdef CONFIG_X86_INTEL_LPSS
+
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+#include <asm/iosf_mbi.h>
+
+#define LPSS_ADDR(desc) ((unsigned long)&desc)
+
+#define LPSS_CLK_SIZE	0x04
+#define LPSS_LTR_SIZE	0x18
+
+/* Offsets relative to LPSS_PRIVATE_OFFSET */
+#define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
+#define LPSS_RESETS			0x04
+#define LPSS_RESETS_RESET_FUNC		BIT(0)
+#define LPSS_RESETS_RESET_APB		BIT(1)
+#define LPSS_GENERAL			0x08
+#define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
+#define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
+#define LPSS_SW_LTR			0x10
+#define LPSS_AUTO_LTR			0x14
+#define LPSS_LTR_SNOOP_REQ		BIT(15)
+#define LPSS_LTR_SNOOP_MASK		0x0000FFFF
+#define LPSS_LTR_SNOOP_LAT_1US		0x800
+#define LPSS_LTR_SNOOP_LAT_32US		0xC00
+#define LPSS_LTR_SNOOP_LAT_SHIFT	5
+#define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
+#define LPSS_LTR_MAX_VAL		0x3FF
+#define LPSS_TX_INT			0x20
+#define LPSS_TX_INT_MASK		BIT(1)
+
+#define LPSS_PRV_REG_COUNT		9
+
+/* LPSS Flags */
+#define LPSS_CLK			BIT(0)
+#define LPSS_CLK_GATE			BIT(1)
+#define LPSS_CLK_DIVIDER		BIT(2)
+#define LPSS_LTR			BIT(3)
+#define LPSS_SAVE_CTX			BIT(4)
+#define LPSS_NO_D3_DELAY		BIT(5)
+
+/* Crystal Cove PMIC shares same ACPI ID between different platforms */
+#define BYT_CRC_HRV			2
+#define CHT_CRC_HRV			3
+
+struct lpss_private_data;
+
+struct lpss_device_desc {
+	unsigned int flags;
+	const char *clk_con_id;
+	unsigned int prv_offset;
+	size_t prv_size_override;
+	struct property_entry *properties;
+	void (*setup)(struct lpss_private_data *pdata);
+	bool resume_from_noirq;
+};
+
+static const struct lpss_device_desc lpss_dma_desc = {
+	.flags = LPSS_CLK,
+};
+
+struct lpss_private_data {
+	struct acpi_device *adev;
+	void __iomem *mmio_base;
+	resource_size_t mmio_size;
+	unsigned int fixed_clk_rate;
+	struct clk *clk;
+	const struct lpss_device_desc *dev_desc;
+	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
+};
+
+/* Devices which need to be in D3 before lpss_iosf_enter_d3_state() proceeds */
+static u32 pmc_atom_d3_mask = 0xfe000ffe;
+
+/* LPSS run time quirks */
+static unsigned int lpss_quirks;
+
+/*
+ * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
+ *
+ * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
+ * it can be powered off automatically whenever the last LPSS device goes down.
+ * In case of no power any access to the DMA controller will hang the system.
+ * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
+ * well as on ASuS T100TA transformer.
+ *
+ * This quirk overrides power state of entire LPSS island to keep DMA powered
+ * on whenever we have at least one other device in use.
+ */
+#define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
+
+/* UART Component Parameter Register */
+#define LPSS_UART_CPR			0xF4
+#define LPSS_UART_CPR_AFCE		BIT(4)
+
+static void lpss_uart_setup(struct lpss_private_data *pdata)
+{
+	unsigned int offset;
+	u32 val;
+
+	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
+	val = readl(pdata->mmio_base + offset);
+	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
+
+	val = readl(pdata->mmio_base + LPSS_UART_CPR);
+	if (!(val & LPSS_UART_CPR_AFCE)) {
+		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
+		val = readl(pdata->mmio_base + offset);
+		val |= LPSS_GENERAL_UART_RTS_OVRD;
+		writel(val, pdata->mmio_base + offset);
+	}
+}
+
+static void lpss_deassert_reset(struct lpss_private_data *pdata)
+{
+	unsigned int offset;
+	u32 val;
+
+	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
+	val = readl(pdata->mmio_base + offset);
+	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
+	writel(val, pdata->mmio_base + offset);
+}
+
+/*
+ * BYT PWM used for backlight control by the i915 driver on systems without
+ * the Crystal Cove PMIC.
+ */
+static struct pwm_lookup byt_pwm_lookup[] = {
+	PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
+			       "pwm_backlight", 0, PWM_POLARITY_NORMAL,
+			       "pwm-lpss-platform"),
+};
+
+static void byt_pwm_setup(struct lpss_private_data *pdata)
+{
+	struct acpi_device *adev = pdata->adev;
+
+	/* Only call pwm_add_table for the first PWM controller */
+	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
+		return;
+
+	if (!acpi_dev_present("INT33FD", NULL, BYT_CRC_HRV))
+		pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
+}
+
+#define LPSS_I2C_ENABLE			0x6c
+
+static void byt_i2c_setup(struct lpss_private_data *pdata)
+{
+	const char *uid_str = acpi_device_uid(pdata->adev);
+	acpi_handle handle = pdata->adev->handle;
+	unsigned long long shared_host = 0;
+	acpi_status status;
+	long uid = 0;
+
+	/* Expected to always be true, but better safe then sorry */
+	if (uid_str)
+		uid = simple_strtol(uid_str, NULL, 10);
+
+	/* Detect I2C bus shared with PUNIT and ignore its d3 status */
+	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
+	if (ACPI_SUCCESS(status) && shared_host && uid)
+		pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
+
+	lpss_deassert_reset(pdata);
+
+	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
+		pdata->fixed_clk_rate = 133000000;
+
+	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
+}
+
+/* BSW PWM used for backlight control by the i915 driver */
+static struct pwm_lookup bsw_pwm_lookup[] = {
+	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
+			       "pwm_backlight", 0, PWM_POLARITY_NORMAL,
+			       "pwm-lpss-platform"),
+};
+
+static void bsw_pwm_setup(struct lpss_private_data *pdata)
+{
+	struct acpi_device *adev = pdata->adev;
+
+	/* Only call pwm_add_table for the first PWM controller */
+	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
+		return;
+
+	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
+}
+
+static const struct lpss_device_desc lpt_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
+	.prv_offset = 0x800,
+};
+
+static const struct lpss_device_desc lpt_i2c_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
+	.prv_offset = 0x800,
+};
+
+static struct property_entry uart_properties[] = {
+	PROPERTY_ENTRY_U32("reg-io-width", 4),
+	PROPERTY_ENTRY_U32("reg-shift", 2),
+	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
+	{ },
+};
+
+static const struct lpss_device_desc lpt_uart_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
+	.clk_con_id = "baudclk",
+	.prv_offset = 0x800,
+	.setup = lpss_uart_setup,
+	.properties = uart_properties,
+};
+
+static const struct lpss_device_desc lpt_sdio_dev_desc = {
+	.flags = LPSS_LTR,
+	.prv_offset = 0x1000,
+	.prv_size_override = 0x1018,
+};
+
+static const struct lpss_device_desc byt_pwm_dev_desc = {
+	.flags = LPSS_SAVE_CTX,
+	.prv_offset = 0x800,
+	.setup = byt_pwm_setup,
+};
+
+static const struct lpss_device_desc bsw_pwm_dev_desc = {
+	.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
+	.prv_offset = 0x800,
+	.setup = bsw_pwm_setup,
+};
+
+static const struct lpss_device_desc byt_uart_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
+	.clk_con_id = "baudclk",
+	.prv_offset = 0x800,
+	.setup = lpss_uart_setup,
+	.properties = uart_properties,
+};
+
+static const struct lpss_device_desc bsw_uart_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
+			| LPSS_NO_D3_DELAY,
+	.clk_con_id = "baudclk",
+	.prv_offset = 0x800,
+	.setup = lpss_uart_setup,
+	.properties = uart_properties,
+};
+
+static const struct lpss_device_desc byt_spi_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
+	.prv_offset = 0x400,
+};
+
+static const struct lpss_device_desc byt_sdio_dev_desc = {
+	.flags = LPSS_CLK,
+};
+
+static const struct lpss_device_desc byt_i2c_dev_desc = {
+	.flags = LPSS_CLK | LPSS_SAVE_CTX,
+	.prv_offset = 0x800,
+	.setup = byt_i2c_setup,
+	.resume_from_noirq = true,
+};
+
+static const struct lpss_device_desc bsw_i2c_dev_desc = {
+	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
+	.prv_offset = 0x800,
+	.setup = byt_i2c_setup,
+	.resume_from_noirq = true,
+};
+
+static const struct lpss_device_desc bsw_spi_dev_desc = {
+	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
+			| LPSS_NO_D3_DELAY,
+	.prv_offset = 0x400,
+	.setup = lpss_deassert_reset,
+};
+
+#define ICPU(model)	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
+
+static const struct x86_cpu_id lpss_cpu_ids[] = {
+	ICPU(INTEL_FAM6_ATOM_SILVERMONT),	/* Valleyview, Bay Trail */
+	ICPU(INTEL_FAM6_ATOM_AIRMONT),	/* Braswell, Cherry Trail */
+	{}
+};
+
+#else
+
+#define LPSS_ADDR(desc) (0UL)
+
+#endif /* CONFIG_X86_INTEL_LPSS */
+
+static const struct acpi_device_id acpi_lpss_device_ids[] = {
+	/* Generic LPSS devices */
+	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
+
+	/* Lynxpoint LPSS devices */
+	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
+	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
+	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
+	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
+	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
+	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
+	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
+	{ "INT33C7", },
+
+	/* BayTrail LPSS devices */
+	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
+	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
+	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
+	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
+	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
+	{ "INT33B2", },
+	{ "INT33FC", },
+
+	/* Braswell LPSS devices */
+	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
+	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
+	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
+	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
+	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
+	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
+
+	/* Broadwell LPSS devices */
+	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
+	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
+	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
+	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
+	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
+	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
+	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
+	{ "INT3437", },
+
+	/* Wildcat Point LPSS devices */
+	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
+
+	{ }
+};
+
+#ifdef CONFIG_X86_INTEL_LPSS
+
+static int is_memory(struct acpi_resource *res, void *not_used)
+{
+	struct resource r;
+	return !acpi_dev_resource_memory(res, &r);
+}
+
+/* LPSS main clock device. */
+static struct platform_device *lpss_clk_dev;
+
+static inline void lpt_register_clock_device(void)
+{
+	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
+}
+
+static int register_device_clock(struct acpi_device *adev,
+				 struct lpss_private_data *pdata)
+{
+	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
+	const char *devname = dev_name(&adev->dev);
+	struct clk *clk;
+	struct lpss_clk_data *clk_data;
+	const char *parent, *clk_name;
+	void __iomem *prv_base;
+
+	if (!lpss_clk_dev)
+		lpt_register_clock_device();
+
+	clk_data = platform_get_drvdata(lpss_clk_dev);
+	if (!clk_data)
+		return -ENODEV;
+	clk = clk_data->clk;
+
+	if (!pdata->mmio_base
+	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
+		return -ENODATA;
+
+	parent = clk_data->name;
+	prv_base = pdata->mmio_base + dev_desc->prv_offset;
+
+	if (pdata->fixed_clk_rate) {
+		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
+					      pdata->fixed_clk_rate);
+		goto out;
+	}
+
+	if (dev_desc->flags & LPSS_CLK_GATE) {
+		clk = clk_register_gate(NULL, devname, parent, 0,
+					prv_base, 0, 0, NULL);
+		parent = devname;
+	}
+
+	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
+		/* Prevent division by zero */
+		if (!readl(prv_base))
+			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
+
+		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
+		if (!clk_name)
+			return -ENOMEM;
+		clk = clk_register_fractional_divider(NULL, clk_name, parent,
+						      0, prv_base,
+						      1, 15, 16, 15, 0, NULL);
+		parent = clk_name;
+
+		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
+		if (!clk_name) {
+			kfree(parent);
+			return -ENOMEM;
+		}
+		clk = clk_register_gate(NULL, clk_name, parent,
+					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+					prv_base, 31, 0, NULL);
+		kfree(parent);
+		kfree(clk_name);
+	}
+out:
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	pdata->clk = clk;
+	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
+	return 0;
+}
+
+struct lpss_device_links {
+	const char *supplier_hid;
+	const char *supplier_uid;
+	const char *consumer_hid;
+	const char *consumer_uid;
+	u32 flags;
+};
+
+/*
+ * The _DEP method is used to identify dependencies but instead of creating
+ * device links for every handle in _DEP, only links in the following list are
+ * created. That is necessary because, in the general case, _DEP can refer to
+ * devices that might not have drivers, or that are on different buses, or where
+ * the supplier is not enumerated until after the consumer is probed.
+ */
+static const struct lpss_device_links lpss_device_links[] = {
+	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
+};
+
+static bool hid_uid_match(const char *hid1, const char *uid1,
+			  const char *hid2, const char *uid2)
+{
+	return !strcmp(hid1, hid2) && uid1 && uid2 && !strcmp(uid1, uid2);
+}
+
+static bool acpi_lpss_is_supplier(struct acpi_device *adev,
+				  const struct lpss_device_links *link)
+{
+	return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev),
+			     link->supplier_hid, link->supplier_uid);
+}
+
+static bool acpi_lpss_is_consumer(struct acpi_device *adev,
+				  const struct lpss_device_links *link)
+{
+	return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev),
+			     link->consumer_hid, link->consumer_uid);
+}
+
+struct hid_uid {
+	const char *hid;
+	const char *uid;
+};
+
+static int match_hid_uid(struct device *dev, void *data)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct hid_uid *id = data;
+
+	if (!adev)
+		return 0;
+
+	return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev),
+			     id->hid, id->uid);
+}
+
+static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
+{
+	struct device *dev;
+
+	struct hid_uid data = {
+		.hid = hid,
+		.uid = uid,
+	};
+
+	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
+	if (dev)
+		return dev;
+
+	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
+}
+
+static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
+{
+	struct acpi_handle_list dep_devices;
+	acpi_status status;
+	int i;
+
+	if (!acpi_has_method(adev->handle, "_DEP"))
+		return false;
+
+	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
+					 &dep_devices);
+	if (ACPI_FAILURE(status)) {
+		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
+		return false;
+	}
+
+	for (i = 0; i < dep_devices.count; i++) {
+		if (dep_devices.handles[i] == handle)
+			return true;
+	}
+
+	return false;
+}
+
+static void acpi_lpss_link_consumer(struct device *dev1,
+				    const struct lpss_device_links *link)
+{
+	struct device *dev2;
+
+	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
+	if (!dev2)
+		return;
+
+	if (acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
+		device_link_add(dev2, dev1, link->flags);
+
+	put_device(dev2);
+}
+
+static void acpi_lpss_link_supplier(struct device *dev1,
+				    const struct lpss_device_links *link)
+{
+	struct device *dev2;
+
+	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
+	if (!dev2)
+		return;
+
+	if (acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
+		device_link_add(dev1, dev2, link->flags);
+
+	put_device(dev2);
+}
+
+static void acpi_lpss_create_device_links(struct acpi_device *adev,
+					  struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
+		const struct lpss_device_links *link = &lpss_device_links[i];
+
+		if (acpi_lpss_is_supplier(adev, link))
+			acpi_lpss_link_consumer(&pdev->dev, link);
+
+		if (acpi_lpss_is_consumer(adev, link))
+			acpi_lpss_link_supplier(&pdev->dev, link);
+	}
+}
+
+static int acpi_lpss_create_device(struct acpi_device *adev,
+				   const struct acpi_device_id *id)
+{
+	const struct lpss_device_desc *dev_desc;
+	struct lpss_private_data *pdata;
+	struct resource_entry *rentry;
+	struct list_head resource_list;
+	struct platform_device *pdev;
+	int ret;
+
+	dev_desc = (const struct lpss_device_desc *)id->driver_data;
+	if (!dev_desc) {
+		pdev = acpi_create_platform_device(adev, NULL);
+		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
+	}
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
+	if (ret < 0)
+		goto err_out;
+
+	list_for_each_entry(rentry, &resource_list, node)
+		if (resource_type(rentry->res) == IORESOURCE_MEM) {
+			if (dev_desc->prv_size_override)
+				pdata->mmio_size = dev_desc->prv_size_override;
+			else
+				pdata->mmio_size = resource_size(rentry->res);
+			pdata->mmio_base = ioremap(rentry->res->start,
+						   pdata->mmio_size);
+			break;
+		}
+
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (!pdata->mmio_base) {
+		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
+		adev->pnp.type.platform_id = 0;
+		/* Skip the device, but continue the namespace scan. */
+		ret = 0;
+		goto err_out;
+	}
+
+	pdata->adev = adev;
+	pdata->dev_desc = dev_desc;
+
+	if (dev_desc->setup)
+		dev_desc->setup(pdata);
+
+	if (dev_desc->flags & LPSS_CLK) {
+		ret = register_device_clock(adev, pdata);
+		if (ret) {
+			/* Skip the device, but continue the namespace scan. */
+			ret = 0;
+			goto err_out;
+		}
+	}
+
+	/*
+	 * This works around a known issue in ACPI tables where LPSS devices
+	 * have _PS0 and _PS3 without _PSC (and no power resources), so
+	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
+	 */
+	acpi_device_fix_up_power(adev);
+
+	adev->driver_data = pdata;
+	pdev = acpi_create_platform_device(adev, dev_desc->properties);
+	if (!IS_ERR_OR_NULL(pdev)) {
+		acpi_lpss_create_device_links(adev, pdev);
+		return 1;
+	}
+
+	ret = PTR_ERR(pdev);
+	adev->driver_data = NULL;
+
+ err_out:
+	kfree(pdata);
+	return ret;
+}
+
+static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
+{
+	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
+}
+
+static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
+			     unsigned int reg)
+{
+	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
+}
+
+static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
+{
+	struct acpi_device *adev;
+	struct lpss_private_data *pdata;
+	unsigned long flags;
+	int ret;
+
+	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
+	if (WARN_ON(ret))
+		return ret;
+
+	spin_lock_irqsave(&dev->power.lock, flags);
+	if (pm_runtime_suspended(dev)) {
+		ret = -EAGAIN;
+		goto out;
+	}
+	pdata = acpi_driver_data(adev);
+	if (WARN_ON(!pdata || !pdata->mmio_base)) {
+		ret = -ENODEV;
+		goto out;
+	}
+	*val = __lpss_reg_read(pdata, reg);
+
+ out:
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+	return ret;
+}
+
+static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	u32 ltr_value = 0;
+	unsigned int reg;
+	int ret;
+
+	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
+	ret = lpss_reg_read(dev, reg, &ltr_value);
+	if (ret)
+		return ret;
+
+	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
+}
+
+static ssize_t lpss_ltr_mode_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	u32 ltr_mode = 0;
+	char *outstr;
+	int ret;
+
+	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
+	if (ret)
+		return ret;
+
+	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
+	return sprintf(buf, "%s\n", outstr);
+}
+
+static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
+static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
+static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
+
+static struct attribute *lpss_attrs[] = {
+	&dev_attr_auto_ltr.attr,
+	&dev_attr_sw_ltr.attr,
+	&dev_attr_ltr_mode.attr,
+	NULL,
+};
+
+static const struct attribute_group lpss_attr_group = {
+	.attrs = lpss_attrs,
+	.name = "lpss_ltr",
+};
+
+static void acpi_lpss_set_ltr(struct device *dev, s32 val)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	u32 ltr_mode, ltr_val;
+
+	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
+	if (val < 0) {
+		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
+			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
+			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
+		}
+		return;
+	}
+	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
+	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
+		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
+		val = LPSS_LTR_MAX_VAL;
+	} else if (val > LPSS_LTR_MAX_VAL) {
+		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
+		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
+	} else {
+		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
+	}
+	ltr_val |= val;
+	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
+	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
+		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
+		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
+	}
+}
+
+#ifdef CONFIG_PM
+/**
+ * acpi_lpss_save_ctx() - Save the private registers of LPSS device
+ * @dev: LPSS device
+ * @pdata: pointer to the private data of the LPSS device
+ *
+ * Most LPSS devices have private registers which may loose their context when
+ * the device is powered down. acpi_lpss_save_ctx() saves those registers into
+ * prv_reg_ctx array.
+ */
+static void acpi_lpss_save_ctx(struct device *dev,
+			       struct lpss_private_data *pdata)
+{
+	unsigned int i;
+
+	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
+		unsigned long offset = i * sizeof(u32);
+
+		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
+		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
+			pdata->prv_reg_ctx[i], offset);
+	}
+}
+
+/**
+ * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
+ * @dev: LPSS device
+ * @pdata: pointer to the private data of the LPSS device
+ *
+ * Restores the registers that were previously stored with acpi_lpss_save_ctx().
+ */
+static void acpi_lpss_restore_ctx(struct device *dev,
+				  struct lpss_private_data *pdata)
+{
+	unsigned int i;
+
+	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
+		unsigned long offset = i * sizeof(u32);
+
+		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
+		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
+			pdata->prv_reg_ctx[i], offset);
+	}
+}
+
+static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
+{
+	/*
+	 * The following delay is needed or the subsequent write operations may
+	 * fail. The LPSS devices are actually PCI devices and the PCI spec
+	 * expects 10ms delay before the device can be accessed after D3 to D0
+	 * transition. However some platforms like BSW does not need this delay.
+	 */
+	unsigned int delay = 10;	/* default 10ms delay */
+
+	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
+		delay = 0;
+
+	msleep(delay);
+}
+
+static int acpi_lpss_activate(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
+
+	ret = acpi_dev_resume(dev);
+	if (ret)
+		return ret;
+
+	acpi_lpss_d3_to_d0_delay(pdata);
+
+	/*
+	 * This is called only on ->probe() stage where a device is either in
+	 * known state defined by BIOS or most likely powered off. Due to this
+	 * we have to deassert reset line to be sure that ->probe() will
+	 * recognize the device.
+	 */
+	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
+		lpss_deassert_reset(pdata);
+
+	return 0;
+}
+
+static void acpi_lpss_dismiss(struct device *dev)
+{
+	acpi_dev_suspend(dev, false);
+}
+
+/* IOSF SB for LPSS island */
+#define LPSS_IOSF_UNIT_LPIOEP		0xA0
+#define LPSS_IOSF_UNIT_LPIO1		0xAB
+#define LPSS_IOSF_UNIT_LPIO2		0xAC
+
+#define LPSS_IOSF_PMCSR			0x84
+#define LPSS_PMCSR_D0			0
+#define LPSS_PMCSR_D3hot		3
+#define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
+
+#define LPSS_IOSF_GPIODEF0		0x154
+#define LPSS_GPIODEF0_DMA1_D3		BIT(2)
+#define LPSS_GPIODEF0_DMA2_D3		BIT(3)
+#define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
+#define LPSS_GPIODEF0_DMA_LLP		BIT(13)
+
+static DEFINE_MUTEX(lpss_iosf_mutex);
+static bool lpss_iosf_d3_entered = true;
+
+static void lpss_iosf_enter_d3_state(void)
+{
+	u32 value1 = 0;
+	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
+	u32 value2 = LPSS_PMCSR_D3hot;
+	u32 mask2 = LPSS_PMCSR_Dx_MASK;
+	/*
+	 * PMC provides an information about actual status of the LPSS devices.
+	 * Here we read the values related to LPSS power island, i.e. LPSS
+	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
+	 */
+	u32 func_dis, d3_sts_0, pmc_status;
+	int ret;
+
+	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
+	if (ret)
+		return;
+
+	mutex_lock(&lpss_iosf_mutex);
+
+	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
+	if (ret)
+		goto exit;
+
+	/*
+	 * Get the status of entire LPSS power island per device basis.
+	 * Shutdown both LPSS DMA controllers if and only if all other devices
+	 * are already in D3hot.
+	 */
+	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
+	if (pmc_status)
+		goto exit;
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
+			LPSS_IOSF_GPIODEF0, value1, mask1);
+
+	lpss_iosf_d3_entered = true;
+
+exit:
+	mutex_unlock(&lpss_iosf_mutex);
+}
+
+static void lpss_iosf_exit_d3_state(void)
+{
+	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
+		     LPSS_GPIODEF0_DMA_LLP;
+	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
+	u32 value2 = LPSS_PMCSR_D0;
+	u32 mask2 = LPSS_PMCSR_Dx_MASK;
+
+	mutex_lock(&lpss_iosf_mutex);
+
+	if (!lpss_iosf_d3_entered)
+		goto exit;
+
+	lpss_iosf_d3_entered = false;
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
+			LPSS_IOSF_GPIODEF0, value1, mask1);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+exit:
+	mutex_unlock(&lpss_iosf_mutex);
+}
+
+static int acpi_lpss_suspend(struct device *dev, bool wakeup)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
+
+	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
+		acpi_lpss_save_ctx(dev, pdata);
+
+	ret = acpi_dev_suspend(dev, wakeup);
+
+	/*
+	 * This call must be last in the sequence, otherwise PMC will return
+	 * wrong status for devices being about to be powered off. See
+	 * lpss_iosf_enter_d3_state() for further information.
+	 */
+	if (acpi_target_system_state() == ACPI_STATE_S0 &&
+	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
+		lpss_iosf_enter_d3_state();
+
+	return ret;
+}
+
+static int acpi_lpss_resume(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
+
+	/*
+	 * This call is kept first to be in symmetry with
+	 * acpi_lpss_runtime_suspend() one.
+	 */
+	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
+		lpss_iosf_exit_d3_state();
+
+	ret = acpi_dev_resume(dev);
+	if (ret)
+		return ret;
+
+	acpi_lpss_d3_to_d0_delay(pdata);
+
+	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
+		acpi_lpss_restore_ctx(dev, pdata);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_lpss_do_suspend_late(struct device *dev)
+{
+	int ret;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	ret = pm_generic_suspend_late(dev);
+	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
+}
+
+static int acpi_lpss_suspend_late(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+	if (pdata->dev_desc->resume_from_noirq)
+		return 0;
+
+	return acpi_lpss_do_suspend_late(dev);
+}
+
+static int acpi_lpss_suspend_noirq(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
+
+	if (pdata->dev_desc->resume_from_noirq) {
+		/*
+		 * The driver's ->suspend_late callback will be invoked by
+		 * acpi_lpss_do_suspend_late(), with the assumption that the
+		 * driver really wanted to run that code in ->suspend_noirq, but
+		 * it could not run after acpi_dev_suspend() and the driver
+		 * expected the latter to be called in the "late" phase.
+		 */
+		ret = acpi_lpss_do_suspend_late(dev);
+		if (ret)
+			return ret;
+	}
+
+	return acpi_subsys_suspend_noirq(dev);
+}
+
+static int acpi_lpss_do_resume_early(struct device *dev)
+{
+	int ret = acpi_lpss_resume(dev);
+
+	return ret ? ret : pm_generic_resume_early(dev);
+}
+
+static int acpi_lpss_resume_early(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+	if (pdata->dev_desc->resume_from_noirq)
+		return 0;
+
+	return acpi_lpss_do_resume_early(dev);
+}
+
+static int acpi_lpss_resume_noirq(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
+
+	/* Follow acpi_subsys_resume_noirq(). */
+	if (dev_pm_may_skip_resume(dev))
+		return 0;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		pm_runtime_set_active(dev);
+
+	ret = pm_generic_resume_noirq(dev);
+	if (ret)
+		return ret;
+
+	if (!pdata->dev_desc->resume_from_noirq)
+		return 0;
+
+	/*
+	 * The driver's ->resume_early callback will be invoked by
+	 * acpi_lpss_do_resume_early(), with the assumption that the driver
+	 * really wanted to run that code in ->resume_noirq, but it could not
+	 * run before acpi_dev_resume() and the driver expected the latter to be
+	 * called in the "early" phase.
+	 */
+	return acpi_lpss_do_resume_early(dev);
+}
+
+static int acpi_lpss_do_restore_early(struct device *dev)
+{
+	int ret = acpi_lpss_resume(dev);
+
+	return ret ? ret : pm_generic_restore_early(dev);
+}
+
+static int acpi_lpss_restore_early(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+	if (pdata->dev_desc->resume_from_noirq)
+		return 0;
+
+	return acpi_lpss_do_restore_early(dev);
+}
+
+static int acpi_lpss_restore_noirq(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
+
+	ret = pm_generic_restore_noirq(dev);
+	if (ret)
+		return ret;
+
+	if (!pdata->dev_desc->resume_from_noirq)
+		return 0;
+
+	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
+	return acpi_lpss_do_restore_early(dev);
+}
+
+static int acpi_lpss_do_poweroff_late(struct device *dev)
+{
+	int ret = pm_generic_poweroff_late(dev);
+
+	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
+}
+
+static int acpi_lpss_poweroff_late(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	if (pdata->dev_desc->resume_from_noirq)
+		return 0;
+
+	return acpi_lpss_do_poweroff_late(dev);
+}
+
+static int acpi_lpss_poweroff_noirq(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	if (pdata->dev_desc->resume_from_noirq) {
+		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
+		int ret = acpi_lpss_do_poweroff_late(dev);
+		if (ret)
+			return ret;
+	}
+
+	return pm_generic_poweroff_noirq(dev);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static int acpi_lpss_runtime_suspend(struct device *dev)
+{
+	int ret = pm_generic_runtime_suspend(dev);
+
+	return ret ? ret : acpi_lpss_suspend(dev, true);
+}
+
+static int acpi_lpss_runtime_resume(struct device *dev)
+{
+	int ret = acpi_lpss_resume(dev);
+
+	return ret ? ret : pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM */
+
+static struct dev_pm_domain acpi_lpss_pm_domain = {
+#ifdef CONFIG_PM
+	.activate = acpi_lpss_activate,
+	.dismiss = acpi_lpss_dismiss,
+#endif
+	.ops = {
+#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
+		.prepare = acpi_subsys_prepare,
+		.complete = acpi_subsys_complete,
+		.suspend = acpi_subsys_suspend,
+		.suspend_late = acpi_lpss_suspend_late,
+		.suspend_noirq = acpi_lpss_suspend_noirq,
+		.resume_noirq = acpi_lpss_resume_noirq,
+		.resume_early = acpi_lpss_resume_early,
+		.freeze = acpi_subsys_freeze,
+		.poweroff = acpi_subsys_poweroff,
+		.poweroff_late = acpi_lpss_poweroff_late,
+		.poweroff_noirq = acpi_lpss_poweroff_noirq,
+		.restore_noirq = acpi_lpss_restore_noirq,
+		.restore_early = acpi_lpss_restore_early,
+#endif
+		.runtime_suspend = acpi_lpss_runtime_suspend,
+		.runtime_resume = acpi_lpss_runtime_resume,
+#endif
+	},
+};
+
+static int acpi_lpss_platform_notify(struct notifier_block *nb,
+				     unsigned long action, void *data)
+{
+	struct platform_device *pdev = to_platform_device(data);
+	struct lpss_private_data *pdata;
+	struct acpi_device *adev;
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
+	if (!id || !id->driver_data)
+		return 0;
+
+	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
+		return 0;
+
+	pdata = acpi_driver_data(adev);
+	if (!pdata)
+		return 0;
+
+	if (pdata->mmio_base &&
+	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
+		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
+		return 0;
+	}
+
+	switch (action) {
+	case BUS_NOTIFY_BIND_DRIVER:
+		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
+		break;
+	case BUS_NOTIFY_DRIVER_NOT_BOUND:
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		dev_pm_domain_set(&pdev->dev, NULL);
+		break;
+	case BUS_NOTIFY_ADD_DEVICE:
+		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
+		if (pdata->dev_desc->flags & LPSS_LTR)
+			return sysfs_create_group(&pdev->dev.kobj,
+						  &lpss_attr_group);
+		break;
+	case BUS_NOTIFY_DEL_DEVICE:
+		if (pdata->dev_desc->flags & LPSS_LTR)
+			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
+		dev_pm_domain_set(&pdev->dev, NULL);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct notifier_block acpi_lpss_nb = {
+	.notifier_call = acpi_lpss_platform_notify,
+};
+
+static void acpi_lpss_bind(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
+		return;
+
+	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
+		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
+	else
+		dev_err(dev, "MMIO size insufficient to access LTR\n");
+}
+
+static void acpi_lpss_unbind(struct device *dev)
+{
+	dev->power.set_latency_tolerance = NULL;
+}
+
+static struct acpi_scan_handler lpss_handler = {
+	.ids = acpi_lpss_device_ids,
+	.attach = acpi_lpss_create_device,
+	.bind = acpi_lpss_bind,
+	.unbind = acpi_lpss_unbind,
+};
+
+void __init acpi_lpss_init(void)
+{
+	const struct x86_cpu_id *id;
+	int ret;
+
+	ret = lpt_clk_init();
+	if (ret)
+		return;
+
+	id = x86_match_cpu(lpss_cpu_ids);
+	if (id)
+		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
+
+	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
+	acpi_scan_add_handler(&lpss_handler);
+}
+
+#else
+
+static struct acpi_scan_handler lpss_handler = {
+	.ids = acpi_lpss_device_ids,
+};
+
+void __init acpi_lpss_init(void)
+{
+	acpi_scan_add_handler(&lpss_handler);
+}
+
+#endif /* CONFIG_X86_INTEL_LPSS */