Merge branch 'acpi-lpss'

* acpi-lpss:
  ACPI / LPSS: make code less confusing for reader
  ACPI / LPSS: Add support for exposing LTR registers to user space
  ACPI / scan: Add special handler for Intel Lynxpoint LPSS devices

Documentation/ABI/testing/sysfs-devices-lpss_ltr

+What:		/sys/devices/.../lpss_ltr/
+Date:		March 2013
+Contact:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+		The /sys/devices/.../lpss_ltr/ directory is only present for
+		devices included into the Intel Lynxpoint Low Power Subsystem
+		(LPSS).  If present, it contains attributes containing the LTR
+		mode and the values of LTR registers of the device.
+
+What:		/sys/devices/.../lpss_ltr/ltr_mode
+Date:		March 2013
+Contact:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+		The /sys/devices/.../lpss_ltr/ltr_mode attribute contains an
+		integer number (0 or 1) indicating whether or not the devices'
+		LTR functionality is working in the software mode (1).
+
+		This attribute is read-only.  If the device's runtime PM status
+		is not "active", attempts to read from this attribute cause
+		-EAGAIN to be returned.
+
+What:		/sys/devices/.../lpss_ltr/auto_ltr
+Date:		March 2013
+Contact:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+		The /sys/devices/.../lpss_ltr/auto_ltr attribute contains the
+		current value of the device's AUTO_LTR register (raw)
+		represented as an 8-digit hexadecimal number.
+
+		This attribute is read-only.  If the device's runtime PM status
+		is not "active", attempts to read from this attribute cause
+		-EAGAIN to be returned.
+
+What:		/sys/devices/.../lpss_ltr/sw_ltr
+Date:		March 2013
+Contact:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+		The /sys/devices/.../lpss_ltr/auto_ltr attribute contains the
+		current value of the device's SW_LTR register (raw) represented
+		as an 8-digit hexadecimal number.
+
+		This attribute is read-only.  If the device's runtime PM status
+		is not "active", attempts to read from this attribute cause
+		-EAGAIN to be returned.

drivers/acpi/Makefile

@@ -39,6 +39,7 @@ acpi-y				+= ec.o
 acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
 acpi-y				+= pci_root.o pci_link.o pci_irq.o
 acpi-y				+= csrt.o
+acpi-$(CONFIG_X86_INTEL_LPSS)	+= acpi_lpss.o
 acpi-y				+= acpi_platform.o
 acpi-y				+= power.o
 acpi-y				+= event.o

drivers/acpi/acpi_lpss.c

+/*
+ * 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/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/clk-lpss.h>
+#include <linux/pm_runtime.h>
+
+#include "internal.h"
+
+ACPI_MODULE_NAME("acpi_lpss");
+
+#define LPSS_CLK_SIZE	0x04
+#define LPSS_LTR_SIZE	0x18
+
+/* Offsets relative to LPSS_PRIVATE_OFFSET */
+#define LPSS_GENERAL			0x08
+#define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
+#define LPSS_SW_LTR			0x10
+#define LPSS_AUTO_LTR			0x14
+
+struct lpss_device_desc {
+	bool clk_required;
+	const char *clk_parent;
+	bool ltr_required;
+	unsigned int prv_offset;
+};
+
+struct lpss_private_data {
+	void __iomem *mmio_base;
+	resource_size_t mmio_size;
+	struct clk *clk;
+	const struct lpss_device_desc *dev_desc;
+};
+
+static struct lpss_device_desc lpt_dev_desc = {
+	.clk_required = true,
+	.clk_parent = "lpss_clk",
+	.prv_offset = 0x800,
+	.ltr_required = true,
+};
+
+static struct lpss_device_desc lpt_sdio_dev_desc = {
+	.prv_offset = 0x1000,
+	.ltr_required = true,
+};
+
+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 },
+	{ "INT33C4", (unsigned long)&lpt_dev_desc },
+	{ "INT33C5", (unsigned long)&lpt_dev_desc },
+	{ "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
+	{ "INT33C7", },
+
+	{ }
+};
+
+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;
+
+	if (!lpss_clk_dev)
+		lpt_register_clock_device();
+
+	if (!dev_desc->clk_parent || !pdata->mmio_base
+	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
+		return -ENODATA;
+
+	pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
+				       dev_desc->clk_parent, 0,
+				       pdata->mmio_base + dev_desc->prv_offset,
+				       0, 0, NULL);
+	if (IS_ERR(pdata->clk))
+		return PTR_ERR(pdata->clk);
+
+	clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev));
+	return 0;
+}
+
+static int acpi_lpss_create_device(struct acpi_device *adev,
+				   const struct acpi_device_id *id)
+{
+	struct lpss_device_desc *dev_desc;
+	struct lpss_private_data *pdata;
+	struct resource_list_entry *rentry;
+	struct list_head resource_list;
+	int ret;
+
+	dev_desc = (struct lpss_device_desc *)id->driver_data;
+	if (!dev_desc)
+		return acpi_create_platform_device(adev, id);
+
+	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) {
+			pdata->mmio_size = resource_size(&rentry->res);
+			pdata->mmio_base = ioremap(rentry->res.start,
+						   pdata->mmio_size);
+			pdata->dev_desc = dev_desc;
+			break;
+		}
+
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (dev_desc->clk_required) {
+		ret = register_device_clock(adev, pdata);
+		if (ret) {
+			/*
+			 * Skip the device, but don't terminate the namespace
+			 * scan.
+			 */
+			kfree(pdata);
+			return 0;
+		}
+	}
+
+	adev->driver_data = pdata;
+	ret = acpi_create_platform_device(adev, id);
+	if (ret > 0)
+		return ret;
+
+	adev->driver_data = NULL;
+
+ err_out:
+	kfree(pdata);
+	return ret;
+}
+
+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 = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + 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 struct attribute_group lpss_attr_group = {
+	.attrs = lpss_attrs,
+	.name = "lpss_ltr",
+};
+
+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;
+	int ret = 0;
+
+	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 || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
+		return 0;
+
+	if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
+		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
+		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);
+
+	return ret;
+}
+
+static struct notifier_block acpi_lpss_nb = {
+	.notifier_call = acpi_lpss_platform_notify,
+};
+
+static struct acpi_scan_handler lpss_handler = {
+	.ids = acpi_lpss_device_ids,
+	.attach = acpi_lpss_create_device,
+};
+
+void __init acpi_lpss_init(void)
+{
+	if (!lpt_clk_init()) {
+		bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
+		acpi_scan_add_handler(&lpss_handler);
+	}
+}

drivers/acpi/acpi_platform.c

@@ -22,9 +22,6 @@
 
 ACPI_MODULE_NAME("platform");
 
-/* Flags for acpi_create_platform_device */
-#define ACPI_PLATFORM_CLK	BIT(0)
-
 /*
  * The following ACPI IDs are known to be suitable for representing as
  * platform devices.
@@ -33,33 +30,9 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
 
 	{ "PNP0D40" },
 
-	/* Haswell LPSS devices */
-	{ "INT33C0", ACPI_PLATFORM_CLK },
-	{ "INT33C1", ACPI_PLATFORM_CLK },
-	{ "INT33C2", ACPI_PLATFORM_CLK },
-	{ "INT33C3", ACPI_PLATFORM_CLK },
-	{ "INT33C4", ACPI_PLATFORM_CLK },
-	{ "INT33C5", ACPI_PLATFORM_CLK },
-	{ "INT33C6", ACPI_PLATFORM_CLK },
-	{ "INT33C7", ACPI_PLATFORM_CLK },
-
 	{ }
 };
 
-static int acpi_create_platform_clks(struct acpi_device *adev)
-{
-	static struct platform_device *pdev;
-
-	/* Create Lynxpoint LPSS clocks */
-	if (!pdev && !strncmp(acpi_device_hid(adev), "INT33C", 6)) {
-		pdev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
-		if (IS_ERR(pdev))
-			return PTR_ERR(pdev);
-	}
-
-	return 0;
-}
-
 /**
  * acpi_create_platform_device - Create platform device for ACPI device node
  * @adev: ACPI device node to create a platform device for.
@@ -71,10 +44,9 @@ static int acpi_create_platform_clks(struct acpi_device *adev)
  *
  * Name of the platform device will be the same as @adev's.
  */
-static int acpi_create_platform_device(struct acpi_device *adev,
-				       const struct acpi_device_id *id)
+int acpi_create_platform_device(struct acpi_device *adev,
+				const struct acpi_device_id *id)
 {
-	unsigned long flags = id->driver_data;
 	struct platform_device *pdev = NULL;
 	struct acpi_device *acpi_parent;
 	struct platform_device_info pdevinfo;
@@ -83,14 +55,6 @@ static int acpi_create_platform_device(struct acpi_device *adev,
 	struct resource *resources;
 	int count;
 
-	if (flags & ACPI_PLATFORM_CLK) {
-		int ret = acpi_create_platform_clks(adev);
-		if (ret) {
-			dev_err(&adev->dev, "failed to create clocks\n");
-			return ret;
-		}
-	}
-
 	/* If the ACPI node already has a physical device attached, skip it. */
 	if (adev->physical_node_count)
 		return 0;

drivers/acpi/internal.h

@@ -59,6 +59,11 @@ int acpi_debugfs_init(void);
 #else
 static inline void acpi_debugfs_init(void) { return; }
 #endif
+#ifdef CONFIG_X86_INTEL_LPSS
+void acpi_lpss_init(void);
+#else
+static inline void acpi_lpss_init(void) {}
+#endif
 
 /* --------------------------------------------------------------------------
                      Device Node Initialization / Removal
@@ -142,4 +147,7 @@ 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);
+
 #endif /* _ACPI_INTERNAL_H_ */

drivers/acpi/scan.c

@@ -2041,6 +2041,7 @@ int __init acpi_scan_init(void)
 	acpi_pci_root_init();
 	acpi_pci_link_init();
 	acpi_platform_init();
+	acpi_lpss_init();
 	acpi_csrt_init();
 	acpi_container_init();
 	acpi_pci_slot_init();

drivers/clk/x86/Makefile

-clk-x86-lpss-objs		:= clk-lpss.o clk-lpt.o
+clk-x86-lpss-objs		:= clk-lpt.o
 obj-$(CONFIG_X86_INTEL_LPSS)	+= clk-x86-lpss.o

drivers/clk/x86/clk-lpss.c

-/*
- * Intel Low Power Subsystem clocks.
- *
- * Copyright (C) 2013, Intel Corporation
- * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
- *	    Heikki Krogerus <heikki.krogerus@linux.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/clk.h>
-#include <linux/clk-provider.h>
-#include <linux/err.h>
-#include <linux/io.h>
-#include <linux/module.h>
-
-static int clk_lpss_is_mmio_resource(struct acpi_resource *res, void *data)
-{
-	struct resource r;
-	return !acpi_dev_resource_memory(res, &r);
-}
-
-static acpi_status clk_lpss_find_mmio(acpi_handle handle, u32 level,
-				      void *data, void **retval)
-{
-	struct resource_list_entry *rentry;
-	struct list_head resource_list;
-	struct acpi_device *adev;
-	const char *uid = data;
-	int ret;
-
-	if (acpi_bus_get_device(handle, &adev))
-		return AE_OK;
-
-	if (uid) {
-		if (!adev->pnp.unique_id)
-			return AE_OK;
-		if (strcmp(uid, adev->pnp.unique_id))
-			return AE_OK;
-	}
-
-	INIT_LIST_HEAD(&resource_list);
-	ret = acpi_dev_get_resources(adev, &resource_list,
-				     clk_lpss_is_mmio_resource, NULL);
-	if (ret < 0)
-		return AE_NO_MEMORY;
-
-	list_for_each_entry(rentry, &resource_list, node)
-		if (resource_type(&rentry->res) == IORESOURCE_MEM) {
-			*(struct resource *)retval = rentry->res;
-			break;
-		}
-
-	acpi_dev_free_resource_list(&resource_list);
-	return AE_OK;
-}
-
-/**
- * clk_register_lpss_gate - register LPSS clock gate
- * @name: name of this clock gate
- * @parent_name: parent clock name
- * @hid: ACPI _HID of the device
- * @uid: ACPI _UID of the device (optional)
- * @offset: LPSS PRV_CLOCK_PARAMS offset
- *
- * Creates and registers LPSS clock gate.
- */
-struct clk *clk_register_lpss_gate(const char *name, const char *parent_name,
-				   const char *hid, const char *uid,
-				   unsigned offset)
-{
-	struct resource res = { };
-	void __iomem *mmio_base;
-	acpi_status status;
-	struct clk *clk;
-
-	/*
-	 * First try to look the device and its mmio resource from the
-	 * ACPI namespace.
-	 */
-	status = acpi_get_devices(hid, clk_lpss_find_mmio, (void *)uid,
-				  (void **)&res);
-	if (ACPI_FAILURE(status) || !res.start)
-		return ERR_PTR(-ENODEV);
-
-	mmio_base = ioremap(res.start, resource_size(&res));
-	if (!mmio_base)
-		return ERR_PTR(-ENOMEM);
-
-	clk = clk_register_gate(NULL, name, parent_name, 0, mmio_base + offset,
-				0, 0, NULL);
-	if (IS_ERR(clk))
-		iounmap(mmio_base);
-
-	return clk;
-}

drivers/clk/x86/clk-lpt.c

@@ -10,7 +10,6 @@
  * published by the Free Software Foundation.
  */
 
-#include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/clk-provider.h>
@@ -18,8 +17,6 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 
-#include "clk-lpss.h"
-
 #define PRV_CLOCK_PARAMS 0x800
 
 static int lpt_clk_probe(struct platform_device *pdev)
@@ -34,40 +31,6 @@ static int lpt_clk_probe(struct platform_device *pdev)
 
 	/* Shared DMA clock */
 	clk_register_clkdev(clk, "hclk", "INTL9C60.0.auto");
-
-	/* SPI clocks */
-	clk = clk_register_lpss_gate("spi0_clk", "lpss_clk", "INT33C0", NULL,
-				     PRV_CLOCK_PARAMS);
-	if (!IS_ERR(clk))
-		clk_register_clkdev(clk, NULL, "INT33C0:00");
-
-	clk = clk_register_lpss_gate("spi1_clk", "lpss_clk", "INT33C1", NULL,
-				     PRV_CLOCK_PARAMS);
-	if (!IS_ERR(clk))
-		clk_register_clkdev(clk, NULL, "INT33C1:00");
-
-	/* I2C clocks */
-	clk = clk_register_lpss_gate("i2c0_clk", "lpss_clk", "INT33C2", NULL,
-				     PRV_CLOCK_PARAMS);
-	if (!IS_ERR(clk))
-		clk_register_clkdev(clk, NULL, "INT33C2:00");
-
-	clk = clk_register_lpss_gate("i2c1_clk", "lpss_clk", "INT33C3", NULL,
-				     PRV_CLOCK_PARAMS);
-	if (!IS_ERR(clk))
-		clk_register_clkdev(clk, NULL, "INT33C3:00");
-
-	/* UART clocks */
-	clk = clk_register_lpss_gate("uart0_clk", "lpss_clk", "INT33C4", NULL,
-				     PRV_CLOCK_PARAMS);
-	if (!IS_ERR(clk))
-		clk_register_clkdev(clk, NULL, "INT33C4:00");
-
-	clk = clk_register_lpss_gate("uart1_clk", "lpss_clk", "INT33C5", NULL,
-				     PRV_CLOCK_PARAMS);
-	if (!IS_ERR(clk))
-		clk_register_clkdev(clk, NULL, "INT33C5:00");
-
 	return 0;
 }
 
@@ -79,8 +42,7 @@ static struct platform_driver lpt_clk_driver = {
 	.probe = lpt_clk_probe,
 };
 
-static int __init lpt_clk_init(void)
+int __init lpt_clk_init(void)
 {
 	return platform_driver_register(&lpt_clk_driver);
 }
-arch_initcall(lpt_clk_init);

drivers/clk/x86/clk-lpss.h → include/linux/platform_data/clk-lpss.h

 /*
- * Intel Low Power Subsystem clock.
+ * Intel Low Power Subsystem clocks.
  *
  * Copyright (C) 2013, Intel Corporation
  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
- *	    Heikki Krogerus <heikki.krogerus@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
@@ -13,24 +13,6 @@
 #ifndef __CLK_LPSS_H
 #define __CLK_LPSS_H
 
-#include <linux/err.h>
-#include <linux/errno.h>
-#include <linux/clk.h>
-
-#ifdef CONFIG_ACPI
-extern struct clk *clk_register_lpss_gate(const char *name,
-					  const char *parent_name,
-					  const char *hid, const char *uid,
-					  unsigned offset);
-#else
-static inline struct clk *clk_register_lpss_gate(const char *name,
-						 const char *parent_name,
-						 const char *hid,
-						 const char *uid,
-						 unsigned offset)
-{
-	return ERR_PTR(-ENODEV);
-}
-#endif
+extern int lpt_clk_init(void);
 
 #endif /* __CLK_LPSS_H */