Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...

63 files changed, 1453 insertions, 866 deletions

diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 1284138e42ab..4bf75597f732 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -102,7 +102,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
 	pdevinfo.id = -1;
 	pdevinfo.res = resources;
 	pdevinfo.num_res = count;
-	pdevinfo.acpi_node.companion = adev;
+	pdevinfo.fwnode = acpi_fwnode_handle(adev);
 	pdevinfo.dma_mask = DMA_BIT_MASK(32);
 	pdev = platform_device_register_full(&pdevinfo);
 	if (IS_ERR(pdev))
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 672263a3832c..63d43677f644 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -531,8 +531,8 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
 		(s16)(battery->rate_now) < 0) {
 		battery->rate_now = abs((s16)battery->rate_now);
-		printk_once(KERN_WARNING FW_BUG "battery: (dis)charge rate"
-			" invalid.\n");
+		printk_once(KERN_WARNING FW_BUG
+			    "battery: (dis)charge rate invalid.\n");
 	}
 
 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
index 9b693d54c743..1d1791935c31 100644
--- a/drivers/acpi/blacklist.c
+++ b/drivers/acpi/blacklist.c
@@ -215,6 +215,14 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
 	},
 	{
 	.callback = dmi_disable_osi_vista,
+	.ident = "VGN-SR19XN",
+	.matches = {
+		     DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		     DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR19XN"),
+		},
+	},
+	{
+	.callback = dmi_disable_osi_vista,
 	.ident = "Toshiba Satellite L355",
 	.matches = {
 		     DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index d9339b442a4e..a688aa243f6c 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -615,7 +615,7 @@ void acpi_dock_add(struct acpi_device *adev)
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.name = "dock";
 	pdevinfo.id = dock_station_count;
-	pdevinfo.acpi_node.companion = adev;
+	pdevinfo.fwnode = acpi_fwnode_handle(adev);
 	pdevinfo.data = &ds;
 	pdevinfo.size_data = sizeof(ds);
 	dd = platform_device_register_full(&pdevinfo);
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index a8dd2f763382..220d6406c9e9 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -137,6 +137,50 @@ static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 
 /* --------------------------------------------------------------------------
+ *                           Logging/Debugging
+ * -------------------------------------------------------------------------- */
+
+/*
+ * Splitters used by the developers to track the boundary of the EC
+ * handling processes.
+ */
+#ifdef DEBUG
+#define EC_DBG_SEP	" "
+#define EC_DBG_DRV	"+++++"
+#define EC_DBG_STM	"====="
+#define EC_DBG_REQ	"*****"
+#define EC_DBG_EVT	"#####"
+#else
+#define EC_DBG_SEP	""
+#define EC_DBG_DRV
+#define EC_DBG_STM
+#define EC_DBG_REQ
+#define EC_DBG_EVT
+#endif
+
+#define ec_log_raw(fmt, ...) \
+	pr_info(fmt "\n", ##__VA_ARGS__)
+#define ec_dbg_raw(fmt, ...) \
+	pr_debug(fmt "\n", ##__VA_ARGS__)
+#define ec_log(filter, fmt, ...) \
+	ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
+#define ec_dbg(filter, fmt, ...) \
+	ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
+
+#define ec_log_drv(fmt, ...) \
+	ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
+#define ec_dbg_drv(fmt, ...) \
+	ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
+#define ec_dbg_stm(fmt, ...) \
+	ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
+#define ec_dbg_req(fmt, ...) \
+	ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
+#define ec_dbg_evt(fmt, ...) \
+	ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
+#define ec_dbg_ref(ec, fmt, ...) \
+	ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
+
+/* --------------------------------------------------------------------------
  *                           Device Flags
  * -------------------------------------------------------------------------- */
 
@@ -159,14 +203,14 @@ static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 {
 	u8 x = inb(ec->command_addr);
 
-	pr_debug("EC_SC(R) = 0x%2.2x "
-		 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
-		 x,
-		 !!(x & ACPI_EC_FLAG_SCI),
-		 !!(x & ACPI_EC_FLAG_BURST),
-		 !!(x & ACPI_EC_FLAG_CMD),
-		 !!(x & ACPI_EC_FLAG_IBF),
-		 !!(x & ACPI_EC_FLAG_OBF));
+	ec_dbg_raw("EC_SC(R) = 0x%2.2x "
+		   "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
+		   x,
+		   !!(x & ACPI_EC_FLAG_SCI),
+		   !!(x & ACPI_EC_FLAG_BURST),
+		   !!(x & ACPI_EC_FLAG_CMD),
+		   !!(x & ACPI_EC_FLAG_IBF),
+		   !!(x & ACPI_EC_FLAG_OBF));
 	return x;
 }
 
@@ -175,20 +219,20 @@ static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 	u8 x = inb(ec->data_addr);
 
 	ec->curr->timestamp = jiffies;
-	pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
+	ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 	return x;
 }
 
 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 {
-	pr_debug("EC_SC(W) = 0x%2.2x\n", command);
+	ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 	outb(command, ec->command_addr);
 	ec->curr->timestamp = jiffies;
 }
 
 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 {
-	pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
+	ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 	outb(data, ec->data_addr);
 	ec->curr->timestamp = jiffies;
 }
@@ -240,7 +284,7 @@ static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 		 * software need to manually trigger a pseudo GPE event on
 		 * EN=1 writes.
 		 */
-		pr_debug("***** Polling quirk *****\n");
+		ec_dbg_raw("Polling quirk");
 		advance_transaction(ec);
 	}
 }
@@ -299,7 +343,7 @@ static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
 {
 	if (!test_bit(flag, &ec->flags)) {
 		acpi_ec_disable_gpe(ec, false);
-		pr_debug("+++++ Polling enabled +++++\n");
+		ec_dbg_drv("Polling enabled");
 		set_bit(flag, &ec->flags);
 	}
 }
@@ -309,7 +353,7 @@ static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
 	if (test_bit(flag, &ec->flags)) {
 		clear_bit(flag, &ec->flags);
 		acpi_ec_enable_gpe(ec, false);
-		pr_debug("+++++ Polling disabled +++++\n");
+		ec_dbg_drv("Polling disabled");
 	}
 }
 
@@ -335,7 +379,7 @@ static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 static void acpi_ec_submit_query(struct acpi_ec *ec)
 {
 	if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
-		pr_debug("***** Event started *****\n");
+		ec_dbg_req("Event started");
 		schedule_work(&ec->work);
 	}
 }
@@ -344,7 +388,7 @@ static void acpi_ec_complete_query(struct acpi_ec *ec)
 {
 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
-		pr_debug("***** Event stopped *****\n");
+		ec_dbg_req("Event stopped");
 	}
 }
 
@@ -366,8 +410,8 @@ static void advance_transaction(struct acpi_ec *ec)
 	u8 status;
 	bool wakeup = false;
 
-	pr_debug("===== %s (%d) =====\n",
-		 in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
+	ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
+		   smp_processor_id());
 	/*
 	 * By always clearing STS before handling all indications, we can
 	 * ensure a hardware STS 0->1 change after this clearing can always
@@ -390,8 +434,8 @@ static void advance_transaction(struct acpi_ec *ec)
 				if (t->rlen == t->ri) {
 					t->flags |= ACPI_EC_COMMAND_COMPLETE;
 					if (t->command == ACPI_EC_COMMAND_QUERY)
-						pr_debug("***** Command(%s) hardware completion *****\n",
-							 acpi_ec_cmd_string(t->command));
+						ec_dbg_req("Command(%s) hardware completion",
+							   acpi_ec_cmd_string(t->command));
 					wakeup = true;
 				}
 			} else
@@ -410,8 +454,8 @@ static void advance_transaction(struct acpi_ec *ec)
 			acpi_ec_complete_query(ec);
 			t->rdata[t->ri++] = 0x00;
 			t->flags |= ACPI_EC_COMMAND_COMPLETE;
-			pr_debug("***** Command(%s) software completion *****\n",
-				 acpi_ec_cmd_string(t->command));
+			ec_dbg_req("Command(%s) software completion",
+				   acpi_ec_cmd_string(t->command));
 			wakeup = true;
 		} else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 			acpi_ec_write_cmd(ec, t->command);
@@ -502,21 +546,21 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 		ret = -EINVAL;
 		goto unlock;
 	}
+	ec_dbg_ref(ec, "Increase command");
 	/* following two actions should be kept atomic */
 	ec->curr = t;
-	pr_debug("***** Command(%s) started *****\n",
-		 acpi_ec_cmd_string(t->command));
+	ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 	start_transaction(ec);
 	spin_unlock_irqrestore(&ec->lock, tmp);
 	ret = ec_poll(ec);
 	spin_lock_irqsave(&ec->lock, tmp);
 	if (t->irq_count == ec_storm_threshold)
 		acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
-	pr_debug("***** Command(%s) stopped *****\n",
-		 acpi_ec_cmd_string(t->command));
+	ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 	ec->curr = NULL;
 	/* Disable GPE for command processing (IBF=0/OBF=1) */
 	acpi_ec_complete_request(ec);
+	ec_dbg_ref(ec, "Decrease command");
 unlock:
 	spin_unlock_irqrestore(&ec->lock, tmp);
 	return ret;
@@ -676,11 +720,13 @@ static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 
 	spin_lock_irqsave(&ec->lock, flags);
 	if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
-		pr_debug("+++++ Starting EC +++++\n");
+		ec_dbg_drv("Starting EC");
 		/* Enable GPE for event processing (SCI_EVT=1) */
-		if (!resuming)
+		if (!resuming) {
 			acpi_ec_submit_request(ec);
-		pr_debug("EC started\n");
+			ec_dbg_ref(ec, "Increase driver");
+		}
+		ec_log_drv("EC started");
 	}
 	spin_unlock_irqrestore(&ec->lock, flags);
 }
@@ -702,17 +748,19 @@ static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 
 	spin_lock_irqsave(&ec->lock, flags);
 	if (acpi_ec_started(ec)) {
-		pr_debug("+++++ Stopping EC +++++\n");
+		ec_dbg_drv("Stopping EC");
 		set_bit(EC_FLAGS_STOPPED, &ec->flags);
 		spin_unlock_irqrestore(&ec->lock, flags);
 		wait_event(ec->wait, acpi_ec_stopped(ec));
 		spin_lock_irqsave(&ec->lock, flags);
 		/* Disable GPE for event processing (SCI_EVT=1) */
-		if (!suspending)
+		if (!suspending) {
 			acpi_ec_complete_request(ec);
+			ec_dbg_ref(ec, "Decrease driver");
+		}
 		clear_bit(EC_FLAGS_STARTED, &ec->flags);
 		clear_bit(EC_FLAGS_STOPPED, &ec->flags);
-		pr_debug("EC stopped\n");
+		ec_log_drv("EC stopped");
 	}
 	spin_unlock_irqrestore(&ec->lock, flags);
 }
@@ -824,12 +872,12 @@ static void acpi_ec_run(void *cxt)
 
 	if (!handler)
 		return;
-	pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
+	ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
 	if (handler->func)
 		handler->func(handler->data);
 	else if (handler->handle)
 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
-	pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
+	ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
 	acpi_ec_put_query_handler(handler);
 }
 
@@ -861,8 +909,8 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 		if (value == handler->query_bit) {
 			/* have custom handler for this bit */
 			handler = acpi_ec_get_query_handler(handler);
-			pr_debug("##### Query(0x%02x) scheduled #####\n",
-				 handler->query_bit);
+			ec_dbg_evt("Query(0x%02x) scheduled",
+				   handler->query_bit);
 			status = acpi_os_execute((handler->func) ?
 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 				acpi_ec_run, handler);
@@ -1099,6 +1147,9 @@ static int acpi_ec_add(struct acpi_device *device)
 
 	ret = ec_install_handlers(ec);
 
+	/* Reprobe devices depending on the EC */
+	acpi_walk_dep_device_list(ec->handle);
+
 	/* EC is fully operational, allow queries */
 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index f774c65ecb8b..39c485b0c25c 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -168,7 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	unsigned int node_id;
 	int retval = -EINVAL;
 
-	if (ACPI_COMPANION(dev)) {
+	if (has_acpi_companion(dev)) {
 		if (acpi_dev) {
 			dev_warn(dev, "ACPI companion already set\n");
 			return -EINVAL;
@@ -220,7 +220,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	list_add(&physical_node->node, physnode_list);
 	acpi_dev->physical_node_count++;
 
-	if (!ACPI_COMPANION(dev))
+	if (!has_acpi_companion(dev))
 		ACPI_COMPANION_SET(dev, acpi_dev);
 
 	acpi_physnode_link_name(physical_node_name, node_id);
diff --git a/drivers/acpi/pmic/intel_pmic_crc.c b/drivers/acpi/pmic/intel_pmic_crc.c
index ef7d8ff95abe..42df46a86c25 100644
--- a/drivers/acpi/pmic/intel_pmic_crc.c
+++ b/drivers/acpi/pmic/intel_pmic_crc.c
@@ -207,5 +207,5 @@ static int __init intel_crc_pmic_opregion_driver_init(void)
 }
 module_init(intel_crc_pmic_opregion_driver_init);
 
-MODULE_DESCRIPTION("CrystalCove ACPI opration region driver");
+MODULE_DESCRIPTION("CrystalCove ACPI operation region driver");
 MODULE_LICENSE("GPL");
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index bbca7830e18a..69bc0d888c01 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -114,7 +114,12 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
 	return 0;
 }
 
-/*
+/**
+ * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
+ * @acpi_dev: ACPI device object.
+ * @modalias: Buffer to print into.
+ * @size: Size of the buffer.
+ *
  * Creates hid/cid(s) string needed for modalias and uevent
  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
  * char *modalias: "acpi:IBM0001:ACPI0001"
@@ -122,68 +127,98 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  *         -EINVAL: output error
  *         -ENOMEM: output is truncated
 */
-static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
-			   int size)
+static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
+			       int size)
 {
 	int len;
 	int count;
 	struct acpi_hardware_id *id;
 
-	if (list_empty(&acpi_dev->pnp.ids))
-		return 0;
-
 	/*
-	 * If the device has PRP0001 we expose DT compatible modalias
-	 * instead in form of of:NnameTCcompatible.
+	 * Since we skip PRP0001 from the modalias below, 0 should be returned
+	 * if PRP0001 is the only ACPI/PNP ID in the device's list.
 	 */
-	if (acpi_dev->data.of_compatible) {
-		struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
-		const union acpi_object *of_compatible, *obj;
-		int i, nval;
-		char *c;
-
-		acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
-		/* DT strings are all in lower case */
-		for (c = buf.pointer; *c != '\0'; c++)
-			*c = tolower(*c);
-
-		len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
-		ACPI_FREE(buf.pointer);
-
-		of_compatible = acpi_dev->data.of_compatible;
-		if (of_compatible->type == ACPI_TYPE_PACKAGE) {
-			nval = of_compatible->package.count;
-			obj = of_compatible->package.elements;
-		} else { /* Must be ACPI_TYPE_STRING. */
-			nval = 1;
-			obj = of_compatible;
-		}
-		for (i = 0; i < nval; i++, obj++) {
-			count = snprintf(&modalias[len], size, "C%s",
-					 obj->string.pointer);
-			if (count < 0)
-				return -EINVAL;
-			if (count >= size)
-				return -ENOMEM;
-
-			len += count;
-			size -= count;
-		}
-	} else {
-		len = snprintf(modalias, size, "acpi:");
-		size -= len;
+	count = 0;
+	list_for_each_entry(id, &acpi_dev->pnp.ids, list)
+		if (strcmp(id->id, "PRP0001"))
+			count++;
 
-		list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
-			count = snprintf(&modalias[len], size, "%s:", id->id);
-			if (count < 0)
-				return -EINVAL;
-			if (count >= size)
-				return -ENOMEM;
-			len += count;
-			size -= count;
-		}
+	if (!count)
+		return 0;
+
+	len = snprintf(modalias, size, "acpi:");
+	if (len <= 0)
+		return len;
+
+	size -= len;
+
+	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
+		if (!strcmp(id->id, "PRP0001"))
+			continue;
+
+		count = snprintf(&modalias[len], size, "%s:", id->id);
+		if (count < 0)
+			return -EINVAL;
+
+		if (count >= size)
+			return -ENOMEM;
+
+		len += count;
+		size -= count;
+	}
+	modalias[len] = '\0';
+	return len;
+}
+
+/**
+ * create_of_modalias - Creates DT compatible string for modalias and uevent
+ * @acpi_dev: ACPI device object.
+ * @modalias: Buffer to print into.
+ * @size: Size of the buffer.
+ *
+ * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
+ * only be called for devices having PRP0001 in their list of ACPI/PNP IDs.