summaryrefslogtreecommitdiff
path: root/drivers/acpi/acpi_lpss.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
-rw-r--r--drivers/acpi/acpi_lpss.c292
1 files changed, 292 insertions, 0 deletions
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);
+ }
+}