![Andy Shevchenko](/assets/img/avatar_default.png)
The excerpt like this: if (err) { err = 0; goto error_out; } makes a reader confused even if it's commented. Let's do necessary actions and return no error explicitly. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
293 lines
7 KiB
C
293 lines
7 KiB
C
/*
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* ACPI support for Intel Lynxpoint LPSS.
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*
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* Copyright (C) 2013, Intel Corporation
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* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
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* Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/acpi.h>
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#include <linux/clk.h>
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#include <linux/clkdev.h>
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#include <linux/clk-provider.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/platform_device.h>
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#include <linux/platform_data/clk-lpss.h>
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#include <linux/pm_runtime.h>
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#include "internal.h"
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ACPI_MODULE_NAME("acpi_lpss");
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#define LPSS_CLK_SIZE 0x04
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#define LPSS_LTR_SIZE 0x18
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/* Offsets relative to LPSS_PRIVATE_OFFSET */
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#define LPSS_GENERAL 0x08
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#define LPSS_GENERAL_LTR_MODE_SW BIT(2)
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#define LPSS_SW_LTR 0x10
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#define LPSS_AUTO_LTR 0x14
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struct lpss_device_desc {
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bool clk_required;
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const char *clk_parent;
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bool ltr_required;
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unsigned int prv_offset;
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};
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struct lpss_private_data {
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void __iomem *mmio_base;
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resource_size_t mmio_size;
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struct clk *clk;
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const struct lpss_device_desc *dev_desc;
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};
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static struct lpss_device_desc lpt_dev_desc = {
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.clk_required = true,
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.clk_parent = "lpss_clk",
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.prv_offset = 0x800,
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.ltr_required = true,
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};
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static struct lpss_device_desc lpt_sdio_dev_desc = {
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.prv_offset = 0x1000,
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.ltr_required = true,
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};
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static const struct acpi_device_id acpi_lpss_device_ids[] = {
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/* Lynxpoint LPSS devices */
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{ "INT33C0", (unsigned long)&lpt_dev_desc },
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{ "INT33C1", (unsigned long)&lpt_dev_desc },
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{ "INT33C2", (unsigned long)&lpt_dev_desc },
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{ "INT33C3", (unsigned long)&lpt_dev_desc },
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{ "INT33C4", (unsigned long)&lpt_dev_desc },
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{ "INT33C5", (unsigned long)&lpt_dev_desc },
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{ "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
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{ "INT33C7", },
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{ }
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};
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static int is_memory(struct acpi_resource *res, void *not_used)
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{
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struct resource r;
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return !acpi_dev_resource_memory(res, &r);
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}
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/* LPSS main clock device. */
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static struct platform_device *lpss_clk_dev;
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static inline void lpt_register_clock_device(void)
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{
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lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
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}
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static int register_device_clock(struct acpi_device *adev,
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struct lpss_private_data *pdata)
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{
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const struct lpss_device_desc *dev_desc = pdata->dev_desc;
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if (!lpss_clk_dev)
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lpt_register_clock_device();
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if (!dev_desc->clk_parent || !pdata->mmio_base
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|| pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
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return -ENODATA;
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pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
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dev_desc->clk_parent, 0,
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pdata->mmio_base + dev_desc->prv_offset,
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0, 0, NULL);
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if (IS_ERR(pdata->clk))
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return PTR_ERR(pdata->clk);
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clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev));
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return 0;
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}
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static int acpi_lpss_create_device(struct acpi_device *adev,
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const struct acpi_device_id *id)
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{
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struct lpss_device_desc *dev_desc;
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struct lpss_private_data *pdata;
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struct resource_list_entry *rentry;
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struct list_head resource_list;
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int ret;
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dev_desc = (struct lpss_device_desc *)id->driver_data;
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if (!dev_desc)
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return acpi_create_platform_device(adev, id);
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pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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INIT_LIST_HEAD(&resource_list);
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ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
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if (ret < 0)
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goto err_out;
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list_for_each_entry(rentry, &resource_list, node)
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if (resource_type(&rentry->res) == IORESOURCE_MEM) {
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pdata->mmio_size = resource_size(&rentry->res);
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pdata->mmio_base = ioremap(rentry->res.start,
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pdata->mmio_size);
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pdata->dev_desc = dev_desc;
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break;
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}
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acpi_dev_free_resource_list(&resource_list);
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if (dev_desc->clk_required) {
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ret = register_device_clock(adev, pdata);
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if (ret) {
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/*
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* Skip the device, but don't terminate the namespace
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* scan.
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*/
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kfree(pdata);
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return 0;
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}
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}
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adev->driver_data = pdata;
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ret = acpi_create_platform_device(adev, id);
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if (ret > 0)
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return ret;
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adev->driver_data = NULL;
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err_out:
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kfree(pdata);
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return ret;
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}
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static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
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{
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struct acpi_device *adev;
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struct lpss_private_data *pdata;
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unsigned long flags;
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int ret;
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ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
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if (WARN_ON(ret))
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return ret;
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spin_lock_irqsave(&dev->power.lock, flags);
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if (pm_runtime_suspended(dev)) {
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ret = -EAGAIN;
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goto out;
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}
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pdata = acpi_driver_data(adev);
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if (WARN_ON(!pdata || !pdata->mmio_base)) {
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ret = -ENODEV;
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goto out;
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}
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*val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
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out:
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spin_unlock_irqrestore(&dev->power.lock, flags);
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return ret;
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}
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static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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u32 ltr_value = 0;
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unsigned int reg;
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int ret;
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reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
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ret = lpss_reg_read(dev, reg, <r_value);
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if (ret)
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return ret;
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return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
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}
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static ssize_t lpss_ltr_mode_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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u32 ltr_mode = 0;
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char *outstr;
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int ret;
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ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode);
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if (ret)
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return ret;
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outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
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return sprintf(buf, "%s\n", outstr);
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}
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static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
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static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
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static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
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static struct attribute *lpss_attrs[] = {
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&dev_attr_auto_ltr.attr,
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&dev_attr_sw_ltr.attr,
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&dev_attr_ltr_mode.attr,
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NULL,
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};
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static struct attribute_group lpss_attr_group = {
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.attrs = lpss_attrs,
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.name = "lpss_ltr",
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};
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static int acpi_lpss_platform_notify(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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struct platform_device *pdev = to_platform_device(data);
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struct lpss_private_data *pdata;
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struct acpi_device *adev;
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const struct acpi_device_id *id;
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int ret = 0;
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id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
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if (!id || !id->driver_data)
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return 0;
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if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
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return 0;
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pdata = acpi_driver_data(adev);
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if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
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return 0;
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if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
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dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
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return 0;
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}
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if (action == BUS_NOTIFY_ADD_DEVICE)
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ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
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else if (action == BUS_NOTIFY_DEL_DEVICE)
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sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
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return ret;
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}
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static struct notifier_block acpi_lpss_nb = {
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.notifier_call = acpi_lpss_platform_notify,
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};
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static struct acpi_scan_handler lpss_handler = {
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.ids = acpi_lpss_device_ids,
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.attach = acpi_lpss_create_device,
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};
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void __init acpi_lpss_init(void)
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{
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if (!lpt_clk_init()) {
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bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
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acpi_scan_add_handler(&lpss_handler);
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}
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}
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