Merge branch 'acpi-lpss' into linux-next

* 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

5 files changed, 304 insertions, 38 deletions

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 474fcfeba66c..ecb743bf05a5 100644
--- a/drivers/acpi/Makefile
+++ b/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
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
new file mode 100644
index 000000000000..b1c95422ce74
--- /dev/null
+++ b/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);
+        }
+}
diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 26fce4b8a632..fafec5ddf17f 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/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;
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 7f094adfe05a..6f1afd9118c8 100644
--- a/drivers/acpi/internal.h
+++ b/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_ */
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 8cacc16af6e7..d7f3c8b66fcf 100644
--- a/drivers/acpi/scan.c
+++ b/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();