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Release 4.16 drivers/platform/x86/dell-wmi-descriptor.c

/*
 * Dell WMI descriptor driver
 *
 * Copyright (C) 2017 Dell Inc. All Rights Reserved.
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/acpi.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/wmi.h>
#include "dell-wmi-descriptor.h"


#define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"


struct descriptor_priv {
	
struct list_head list;
	
u32 interface_version;
	
u32 size;
	
u32 hotfix;
};

static int descriptor_valid = -EPROBE_DEFER;
static LIST_HEAD(wmi_list);
static DEFINE_MUTEX(list_mutex);


int dell_wmi_get_descriptor_valid(void) { if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID)) return -ENODEV; return descriptor_valid; }

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Mario Limonciello22100.00%1100.00%
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EXPORT_SYMBOL_GPL(dell_wmi_get_descriptor_valid);
bool dell_wmi_get_interface_version(u32 *version) { struct descriptor_priv *priv; bool ret = false; mutex_lock(&list_mutex); priv = list_first_entry_or_null(&wmi_list, struct descriptor_priv, list); if (priv) { *version = priv->interface_version; ret = true; } mutex_unlock(&list_mutex); return ret; }

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Mario Limonciello64100.00%1100.00%
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EXPORT_SYMBOL_GPL(dell_wmi_get_interface_version);
bool dell_wmi_get_size(u32 *size) { struct descriptor_priv *priv; bool ret = false; mutex_lock(&list_mutex); priv = list_first_entry_or_null(&wmi_list, struct descriptor_priv, list); if (priv) { *size = priv->size; ret = true; } mutex_unlock(&list_mutex); return ret; }

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Mario Limonciello64100.00%1100.00%
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EXPORT_SYMBOL_GPL(dell_wmi_get_size);
bool dell_wmi_get_hotfix(u32 *hotfix) { struct descriptor_priv *priv; bool ret = false; mutex_lock(&list_mutex); priv = list_first_entry_or_null(&wmi_list, struct descriptor_priv, list); if (priv) { *hotfix = priv->hotfix; ret = true; } mutex_unlock(&list_mutex); return ret; }

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Mario Limonciello64100.00%1100.00%
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EXPORT_SYMBOL_GPL(dell_wmi_get_hotfix); /* * Descriptor buffer is 128 byte long and contains: * * Name Offset Length Value * Vendor Signature 0 4 "DELL" * Object Signature 4 4 " WMI" * WMI Interface Version 8 4 <version> * WMI buffer length 12 4 <length> * WMI hotfix number 16 4 <hotfix> */
static int dell_wmi_descriptor_probe(struct wmi_device *wdev) { union acpi_object *obj = NULL; struct descriptor_priv *priv; u32 *buffer; int ret; obj = wmidev_block_query(wdev, 0); if (!obj) { dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n"); ret = -EIO; goto out; } if (obj->type != ACPI_TYPE_BUFFER) { dev_err(&wdev->dev, "Dell descriptor has wrong type\n"); ret = -EINVAL; descriptor_valid = ret; goto out; } /* Although it's not technically a failure, this would lead to * unexpected behavior */ if (obj->buffer.length != 128) { dev_err(&wdev->dev, "Dell descriptor buffer has unexpected length (%d)\n", obj->buffer.length); ret = -EINVAL; descriptor_valid = ret; goto out; } buffer = (u32 *)obj->buffer.pointer; if (strncmp(obj->string.pointer, "DELL WMI", 8) != 0) { dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%8ph)\n", buffer); ret = -EINVAL; descriptor_valid = ret; goto out; } descriptor_valid = 0; if (buffer[2] != 0 && buffer[2] != 1) dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%lu)\n", (unsigned long) buffer[2]); priv = devm_kzalloc(&wdev->dev, sizeof(struct descriptor_priv), GFP_KERNEL); if (!priv) { ret = -ENOMEM; goto out; } priv->interface_version = buffer[2]; priv->size = buffer[3]; priv->hotfix = buffer[4]; ret = 0; dev_set_drvdata(&wdev->dev, priv); mutex_lock(&list_mutex); list_add_tail(&priv->list, &wmi_list); mutex_unlock(&list_mutex); dev_dbg(&wdev->dev, "Detected Dell WMI interface version %lu, buffer size %lu, hotfix %lu\n", (unsigned long) priv->interface_version, (unsigned long) priv->size, (unsigned long) priv->hotfix); out: kfree(obj); return ret; }

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Mario Limonciello372100.00%4100.00%
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static int dell_wmi_descriptor_remove(struct wmi_device *wdev) { struct descriptor_priv *priv = dev_get_drvdata(&wdev->dev); mutex_lock(&list_mutex); list_del(&priv->list); mutex_unlock(&list_mutex); return 0; }

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Mario Limonciello47100.00%1100.00%
Total47100.00%1100.00%

static const struct wmi_device_id dell_wmi_descriptor_id_table[] = { { .guid_string = DELL_WMI_DESCRIPTOR_GUID }, { }, }; static struct wmi_driver dell_wmi_descriptor_driver = { .driver = { .name = "dell-wmi-descriptor", }, .probe = dell_wmi_descriptor_probe, .remove = dell_wmi_descriptor_remove, .id_table = dell_wmi_descriptor_id_table, }; module_wmi_driver(dell_wmi_descriptor_driver); MODULE_ALIAS("wmi:" DELL_WMI_DESCRIPTOR_GUID); MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>"); MODULE_DESCRIPTION("Dell WMI descriptor driver"); MODULE_LICENSE("GPL");

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Mario Limonciello794100.00%4100.00%
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