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

@@ -0,0 +1,44 @@
+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

@@ -0,0 +1,292 @@
+/*
+ * 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);
+	}
+}