Merge branch 'acpi-lpss' into acpi-enumeration

6 files changed, 294 insertions, 56 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 69e29f409d4..db362a96c38 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -19,6 +19,7 @@
 #include <linux/platform_device.h>
 #include <linux/platform_data/clk-lpss.h>
 #include <linux/pm_runtime.h>
+#include <linux/delay.h>
 
 #include "internal.h"
 
@@ -28,6 +29,7 @@ ACPI_MODULE_NAME("acpi_lpss");
 #define LPSS_LTR_SIZE	0x18
 
 /* Offsets relative to LPSS_PRIVATE_OFFSET */
+#define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
 #define LPSS_GENERAL			0x08
 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
@@ -43,6 +45,8 @@ ACPI_MODULE_NAME("acpi_lpss");
 #define LPSS_TX_INT			0x20
 #define LPSS_TX_INT_MASK		BIT(1)
 
+#define LPSS_PRV_REG_COUNT		9
+
 struct lpss_shared_clock {
 	const char *name;
 	unsigned long rate;
@@ -57,7 +61,9 @@ struct lpss_device_desc {
 	bool ltr_required;
 	unsigned int prv_offset;
 	size_t prv_size_override;
+	bool clk_divider;
 	bool clk_gate;
+	bool save_ctx;
 	struct lpss_shared_clock *shared_clock;
 	void (*setup)(struct lpss_private_data *pdata);
 };
@@ -72,6 +78,7 @@ struct lpss_private_data {
 	resource_size_t mmio_size;
 	struct clk *clk;
 	const struct lpss_device_desc *dev_desc;
+	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
 };
 
 static void lpss_uart_setup(struct lpss_private_data *pdata)
@@ -92,6 +99,14 @@ static struct lpss_device_desc lpt_dev_desc = {
 	.clk_required = true,
 	.prv_offset = 0x800,
 	.ltr_required = true,
+	.clk_divider = true,
+	.clk_gate = true,
+};
+
+static struct lpss_device_desc lpt_i2c_dev_desc = {
+	.clk_required = true,
+	.prv_offset = 0x800,
+	.ltr_required = true,
 	.clk_gate = true,
 };
 
@@ -99,6 +114,7 @@ static struct lpss_device_desc lpt_uart_dev_desc = {
 	.clk_required = true,
 	.prv_offset = 0x800,
 	.ltr_required = true,
+	.clk_divider = true,
 	.clk_gate = true,
 	.setup = lpss_uart_setup,
 };
@@ -116,32 +132,25 @@ static struct lpss_shared_clock pwm_clock = {
 
 static struct lpss_device_desc byt_pwm_dev_desc = {
 	.clk_required = true,
+	.save_ctx = true,
 	.shared_clock = &pwm_clock,
 };
 
-static struct lpss_shared_clock uart_clock = {
-	.name = "uart_clk",
-	.rate = 44236800,
-};
-
 static struct lpss_device_desc byt_uart_dev_desc = {
 	.clk_required = true,
 	.prv_offset = 0x800,
+	.clk_divider = true,
 	.clk_gate = true,
-	.shared_clock = &uart_clock,
+	.save_ctx = true,
 	.setup = lpss_uart_setup,
 };
 
-static struct lpss_shared_clock spi_clock = {
-	.name = "spi_clk",
-	.rate = 50000000,
-};
-
 static struct lpss_device_desc byt_spi_dev_desc = {
 	.clk_required = true,
 	.prv_offset = 0x400,
+	.clk_divider = true,
 	.clk_gate = true,
-	.shared_clock = &spi_clock,
+	.save_ctx = true,
 };
 
 static struct lpss_device_desc byt_sdio_dev_desc = {
@@ -156,6 +165,7 @@ static struct lpss_shared_clock i2c_clock = {
 static struct lpss_device_desc byt_i2c_dev_desc = {
 	.clk_required = true,
 	.prv_offset = 0x800,
+	.save_ctx = true,
 	.shared_clock = &i2c_clock,
 };
 
@@ -166,8 +176,8 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = {
 	/* Lynxpoint LPSS devices */
 	{ "INT33C0", (unsigned long)&lpt_dev_desc },
 	{ "INT33C1", (unsigned long)&lpt_dev_desc },
-	{ "INT33C2", (unsigned long)&lpt_dev_desc },
-	{ "INT33C3", (unsigned long)&lpt_dev_desc },
+	{ "INT33C2", (unsigned long)&lpt_i2c_dev_desc },
+	{ "INT33C3", (unsigned long)&lpt_i2c_dev_desc },
 	{ "INT33C4", (unsigned long)&lpt_uart_dev_desc },
 	{ "INT33C5", (unsigned long)&lpt_uart_dev_desc },
 	{ "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
@@ -183,8 +193,8 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = {
 
 	{ "INT3430", (unsigned long)&lpt_dev_desc },
 	{ "INT3431", (unsigned long)&lpt_dev_desc },
-	{ "INT3432", (unsigned long)&lpt_dev_desc },
-	{ "INT3433", (unsigned long)&lpt_dev_desc },
+	{ "INT3432", (unsigned long)&lpt_i2c_dev_desc },
+	{ "INT3433", (unsigned long)&lpt_i2c_dev_desc },
 	{ "INT3434", (unsigned long)&lpt_uart_dev_desc },
 	{ "INT3435", (unsigned long)&lpt_uart_dev_desc },
 	{ "INT3436", (unsigned long)&lpt_sdio_dev_desc },
@@ -212,9 +222,11 @@ static int register_device_clock(struct acpi_device *adev,
 {
 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 	struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
+	const char *devname = dev_name(&adev->dev);
 	struct clk *clk = ERR_PTR(-ENODEV);
 	struct lpss_clk_data *clk_data;
-	const char *parent;
+	const char *parent, *clk_name;
+	void __iomem *prv_base;
 
 	if (!lpss_clk_dev)
 		lpt_register_clock_device();
@@ -225,7 +237,7 @@ static int register_device_clock(struct acpi_device *adev,
 
 	if (dev_desc->clkdev_name) {
 		clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
-				    dev_name(&adev->dev));
+				    devname);
 		return 0;
 	}
 
@@ -234,6 +246,7 @@ static int register_device_clock(struct acpi_device *adev,
 		return -ENODATA;
 
 	parent = clk_data->name;
+	prv_base = pdata->mmio_base + dev_desc->prv_offset;
 
 	if (shared_clock) {
 		clk = shared_clock->clk;
@@ -247,16 +260,41 @@ static int register_device_clock(struct acpi_device *adev,
 	}
 
 	if (dev_desc->clk_gate) {
-		clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
-					pdata->mmio_base + dev_desc->prv_offset,
-					0, 0, NULL);
-		pdata->clk = clk;
+		clk = clk_register_gate(NULL, devname, parent, 0,
+					prv_base, 0, 0, NULL);
+		parent = devname;
+	}
+
+	if (dev_desc->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);
 	}
 
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 
-	clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
+	pdata->clk = clk;
+	clk_register_clkdev(clk, NULL, devname);
 	return 0;
 }
 
@@ -267,12 +305,14 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 	struct lpss_private_data *pdata;
 	struct resource_list_entry *rentry;
 	struct list_head resource_list;
+	struct platform_device *pdev;
 	int ret;
 
 	dev_desc = (struct lpss_device_desc *)id->driver_data;
-	if (!dev_desc)
-		return acpi_create_platform_device(adev, id);
-
+	if (!dev_desc) {
+		pdev = acpi_create_platform_device(adev);
+		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
+	}
 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
@@ -322,10 +362,13 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 		dev_desc->setup(pdata);
 
 	adev->driver_data = pdata;
-	ret = acpi_create_platform_device(adev, id);
-	if (ret > 0)
-		return ret;
+	pdev = acpi_create_platform_device(adev);
+	if (!IS_ERR_OR_NULL(pdev)) {
+		device_enable_async_suspend(&pdev->dev);
+		return 1;
+	}
 
+	ret = PTR_ERR(pdev);
 	adev->driver_data = NULL;
 
  err_out:
@@ -449,6 +492,126 @@ static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 	}
 }
 
+#ifdef CONFIG_PM
+/**
+ * acpi_lpss_save_ctx() - Save the private registers of LPSS device
+ * @dev: 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 = acpi_driver_data(ACPI_COMPANION(dev));
+	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
+ *
+ * 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 = acpi_driver_data(ACPI_COMPANION(dev));
+	unsigned int i;
+
+	/*
+	 * 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.
+	 */
+	msleep(10);
+
+	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);
+	}
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_lpss_suspend_late(struct device *dev)
+{
+	int ret = pm_generic_suspend_late(dev);
+
+	if (ret)
+		return ret;
+
+	acpi_lpss_save_ctx(dev);
+	return acpi_dev_suspend_late(dev);
+}
+
+static int acpi_lpss_restore_early(struct device *dev)
+{
+	int ret = acpi_dev_resume_early(dev);
+
+	if (ret)
+		return ret;
+
+	acpi_lpss_restore_ctx(dev);
+	return pm_generic_resume_early(dev);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM_RUNTIME
+static int acpi_lpss_runtime_suspend(struct device *dev)
+{
+	int ret = pm_generic_runtime_suspend(dev);
+
+	if (ret)
+		return ret;
+
+	acpi_lpss_save_ctx(dev);
+	return acpi_dev_runtime_suspend(dev);
+}
+
+static int acpi_lpss_runtime_resume(struct device *dev)
+{
+	int ret = acpi_dev_runtime_resume(dev);
+
+	if (ret)
+		return ret;
+
+	acpi_lpss_restore_ctx(dev);
+	return pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM_RUNTIME */
+#endif /* CONFIG_PM */
+
+static struct dev_pm_domain acpi_lpss_pm_domain = {
+	.ops = {
+#ifdef CONFIG_PM_SLEEP
+		.suspend_late = acpi_lpss_suspend_late,
+		.restore_early = acpi_lpss_restore_early,
+		.prepare = acpi_subsys_prepare,
+		.complete = acpi_subsys_complete,
+		.suspend = acpi_subsys_suspend,
+		.resume_early = acpi_subsys_resume_early,
+		.freeze = acpi_subsys_freeze,
+		.poweroff = acpi_subsys_suspend,
+		.poweroff_late = acpi_subsys_suspend_late,
+#endif
+#ifdef CONFIG_PM_RUNTIME
+		.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)
 {
@@ -456,7 +619,6 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 	struct lpss_private_data *pdata;
 	struct acpi_device *adev;
 	const struct acpi_device_id *id;
-	int ret = 0;
 
 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 	if (!id || !id->driver_data)
@@ -466,7 +628,7 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 		return 0;
 
 	pdata = acpi_driver_data(adev);
-	if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
+	if (!pdata || !pdata->mmio_base)
 		return 0;
 
 	if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
@@ -474,12 +636,27 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 		return 0;
 	}
 
-	if (action == BUS_NOTIFY_ADD_DEVICE)
-		ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
-	else if (action == BUS_NOTIFY_DEL_DEVICE)
-		sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
+	switch (action) {
+	case BUS_NOTIFY_BOUND_DRIVER:
+		if (pdata->dev_desc->save_ctx)
+			pdev->dev.pm_domain = &acpi_lpss_pm_domain;
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		if (pdata->dev_desc->save_ctx)
+			pdev->dev.pm_domain = NULL;
+		break;
+	case BUS_NOTIFY_ADD_DEVICE:
+		if (pdata->dev_desc->ltr_required)
+			return sysfs_create_group(&pdev->dev.kobj,
+						  &lpss_attr_group);
+	case BUS_NOTIFY_DEL_DEVICE:
+		if (pdata->dev_desc->ltr_required)
+			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
+	default:
+		break;
+	}
 
-	return ret;
+	return 0;
 }
 
 static struct notifier_block acpi_lpss_nb = {
diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 1d4950388fa..3bb89def229 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -31,6 +31,10 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
 	{ "PNP0D40" },
 	{ "VPC2004" },
 	{ "BCM4752" },
+	{ "LNV4752" },
+	{ "BCM2E1A" },
+	{ "BCM2E39" },
+	{ "BCM2E3D" },
 
 	/* Intel Smart Sound Technology */
 	{ "INT33C8" },
@@ -42,7 +46,6 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
 /**
  * acpi_create_platform_device - Create platform device for ACPI device node
  * @adev: ACPI device node to create a platform device for.
- * @id: ACPI device ID used to match @adev.
  *
  * Check if the given @adev can be represented as a platform device and, if
  * that's the case, create and register a platform device, populate its common
@@ -50,8 +53,7 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
  *
  * Name of the platform device will be the same as @adev's.
  */
-int acpi_create_platform_device(struct acpi_device *adev,
-				const struct acpi_device_id *id)
+struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
 {
 	struct platform_device *pdev = NULL;
 	struct acpi_device *acpi_parent;
@@ -63,19 +65,19 @@ int acpi_create_platform_device(struct acpi_device *adev,
 
 	/* If the ACPI node already has a physical device attached, skip it. */
 	if (adev->physical_node_count)
-		return 0;
+		return NULL;
 
 	INIT_LIST_HEAD(&resource_list);
 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 	if (count < 0) {
-		return 0;
+		return NULL;
 	} else if (count > 0) {
 		resources = kmalloc(count * sizeof(struct resource),
 				    GFP_KERNEL);
 		if (!resources) {
 			dev_err(&adev->dev, "No memory for resources\n");
 			acpi_dev_free_resource_list(&resource_list);
-			return -ENOMEM;
+			return ERR_PTR(-ENOMEM);
 		}
 		count = 0;
 		list_for_each_entry(rentry, &resource_list, node)
@@ -112,22 +114,27 @@ int acpi_create_platform_device(struct acpi_device *adev,
 	pdevinfo.num_res = count;
 	pdevinfo.acpi_node.companion = adev;
 	pdev = platform_device_register_full(&pdevinfo);
-	if (IS_ERR(pdev)) {
+	if (IS_ERR(pdev))
 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
 			PTR_ERR(pdev));
-		pdev = NULL;
-	} else {
+	else
 		dev_dbg(&adev->dev, "created platform device %s\n",
 			dev_name(&pdev->dev));
-	}
 
 	kfree(resources);
+	return pdev;
+}
+
+static int acpi_platform_attach(struct acpi_device *adev,
+				const struct acpi_device_id *id)
+{
+	acpi_create_platform_device(adev);
 	return 1;
 }
 
 static struct acpi_scan_handler platform_handler = {
 	.ids = acpi_platform_device_ids,
-	.attach = acpi_create_platform_device,
+	.attach = acpi_platform_attach,
 };
 
 void __init acpi_platform_init(void)
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index d047739f338..49a51277f81 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -900,18 +900,47 @@ EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
  */
 int acpi_subsys_prepare(struct device *dev)
 {
-	/*
-	 * Devices having power.ignore_children set may still be necessary for
-	 * suspending their children in the next phase of device suspend.
-	 */
-	if (dev->power.ignore_children)
-		pm_runtime_resume(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	u32 sys_target;
+	int ret, state;
+
+	ret = pm_generic_prepare(dev);
+	if (ret < 0)
+		return ret;
+
+	if (!adev || !pm_runtime_suspended(dev)
+	    || device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
+		return 0;
+
+	sys_target = acpi_target_system_state();
+	if (sys_target == ACPI_STATE_S0)
+		return 1;
 
-	return pm_generic_prepare(dev);
+	if (adev->power.flags.dsw_present)
+		return 0;
+
+	ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
+	return !ret && state == adev->power.state;
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
 
 /**
+ * acpi_subsys_complete - Finalize device's resume during system resume.
+ * @dev: Device to handle.
+ */
+void acpi_subsys_complete(struct device *dev)
+{
+	/*
+	 * If the device had been runtime-suspended before the system went into
+	 * the sleep state it is going out of and it has never been resumed till
+	 * now, resume it in case the firmware powered it up.
+	 */
+	if (dev->power.direct_complete)
+		pm_request_resume(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_complete);
+
+/**
  * acpi_subsys_suspend - Run the device driver's suspend callback.
  * @dev: Device to handle.
  *
@@ -923,6 +952,7 @@ int acpi_subsys_suspend(struct device *dev)
 	pm_runtime_resume(dev);
 	return pm_generic_suspend(dev);
 }
+EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
 
 /**
  * acpi_subsys_suspend_late - Suspend device using ACPI.
@@ -968,6 +998,7 @@ int acpi_subsys_freeze(struct device *dev)
 	pm_runtime_resume(dev);
 	return pm_generic_freeze(dev);
 }
+EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
 
 #endif /* CONFIG_PM_SLEEP */
 
@@ -979,6 +1010,7 @@ static struct dev_pm_domain acpi_general_pm_domain = {
 #endif
 #ifdef CONFIG_PM_SLEEP
 		.prepare = acpi_subsys_prepare,
+		.complete = acpi_subsys_complete,
 		.suspend = acpi_subsys_suspend,
 		.suspend_late = acpi_subsys_suspend_late,
 		.resume_early = acpi_subsys_resume_early,
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 957391306cb..bb7de413d06 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -180,8 +180,7 @@ static inline void suspend_nvs_restore(void) {}
   -------------------------------------------------------------------------- */
 struct platform_device;
 
-int acpi_create_platform_device(struct acpi_device *adev,
-				const struct acpi_device_id *id);
+struct platform_device *acpi_create_platform_device(struct acpi_device *adev);
 
 /*--------------------------------------------------------------------------
 					Video
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7efe546a8c4..df6e4c924b3 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1551,9 +1551,13 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
 	 */
 	if (acpi_has_method(device->handle, "_PSC"))
 		device->power.flags.explicit_get = 1;
+
 	if (acpi_has_method(device->handle, "_IRC"))
 		device->power.flags.inrush_current = 1;
 
+	if (acpi_has_method(device->handle, "_DSW"))
+		device->power.flags.dsw_present = 1;
+
 	/*
 	 * Enumerate supported power management states
 	 */
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index c40fb2e81bb..c11e3795431 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -89,6 +89,7 @@ u32 acpi_target_system_state(void)
 {
 	return acpi_target_sleep_state;
 }
+EXPORT_SYMBOL_GPL(acpi_target_system_state);
 
 static bool pwr_btn_event_pending;
 
@@ -611,6 +612,22 @@ static const struct platform_suspend_ops acpi_suspend_ops_old = {
 	.recover = acpi_pm_finish,
 };
 
+static int acpi_freeze_begin(void)
+{
+	acpi_scan_lock_acquire();
+	return 0;
+}
+
+static void acpi_freeze_end(void)
+{
+	acpi_scan_lock_release();
+}
+
+static const struct platform_freeze_ops acpi_freeze_ops = {
+	.begin = acpi_freeze_begin,
+	.end = acpi_freeze_end,
+};
+
 static void acpi_sleep_suspend_setup(void)
 {
 	int i;
@@ -621,7 +638,9 @@ static void acpi_sleep_suspend_setup(void)
 
 	suspend_set_ops(old_suspend_ordering ?
 		&acpi_suspend_ops_old : &acpi_suspend_ops);
+	freeze_set_ops(&acpi_freeze_ops);
 }
+
 #else /* !CONFIG_SUSPEND */
 static inline void acpi_sleep_suspend_setup(void) {}
 #endif /* !CONFIG_SUSPEND */