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	The driver core ignores the return value of struct bus_type::remove() (and so wmi_dev_remove()) because there is only little that can be done. To simplify the quest to make this function return void, let struct wmi_driver::remove() return void, too. All implementers of this callback return 0 already and this way it should be obvious to driver authors that returning an error code is a bad idea. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20210301160404.1677064-1-u.kleine-koenig@pengutronix.de Signed-off-by: Hans de Goede <hdegoede@redhat.com>
		
			
				
	
	
		
			116 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			116 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * WMI embedded Binary MOF driver
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 *
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 * Copyright (c) 2015 Andrew Lutomirski
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 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
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 */
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/acpi.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/sysfs.h>
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#include <linux/types.h>
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#include <linux/wmi.h>
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#define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
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struct bmof_priv {
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	union acpi_object *bmofdata;
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	struct bin_attribute bmof_bin_attr;
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};
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static ssize_t
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read_bmof(struct file *filp, struct kobject *kobj,
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	 struct bin_attribute *attr,
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	 char *buf, loff_t off, size_t count)
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{
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	struct bmof_priv *priv =
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		container_of(attr, struct bmof_priv, bmof_bin_attr);
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	if (off < 0)
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		return -EINVAL;
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	if (off >= priv->bmofdata->buffer.length)
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		return 0;
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	if (count > priv->bmofdata->buffer.length - off)
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		count = priv->bmofdata->buffer.length - off;
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	memcpy(buf, priv->bmofdata->buffer.pointer + off, count);
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	return count;
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}
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static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
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{
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	struct bmof_priv *priv;
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	int ret;
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	priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL);
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	if (!priv)
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		return -ENOMEM;
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	dev_set_drvdata(&wdev->dev, priv);
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	priv->bmofdata = wmidev_block_query(wdev, 0);
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	if (!priv->bmofdata) {
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		dev_err(&wdev->dev, "failed to read Binary MOF\n");
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		return -EIO;
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	}
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	if (priv->bmofdata->type != ACPI_TYPE_BUFFER) {
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		dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
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		ret = -EIO;
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		goto err_free;
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	}
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	sysfs_bin_attr_init(&priv->bmof_bin_attr);
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	priv->bmof_bin_attr.attr.name = "bmof";
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	priv->bmof_bin_attr.attr.mode = 0400;
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	priv->bmof_bin_attr.read = read_bmof;
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	priv->bmof_bin_attr.size = priv->bmofdata->buffer.length;
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	ret = sysfs_create_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
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	if (ret)
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		goto err_free;
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	return 0;
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 err_free:
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	kfree(priv->bmofdata);
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	return ret;
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}
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static void wmi_bmof_remove(struct wmi_device *wdev)
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{
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	struct bmof_priv *priv = dev_get_drvdata(&wdev->dev);
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	sysfs_remove_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
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	kfree(priv->bmofdata);
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}
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static const struct wmi_device_id wmi_bmof_id_table[] = {
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	{ .guid_string = WMI_BMOF_GUID },
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	{ },
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};
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static struct wmi_driver wmi_bmof_driver = {
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	.driver = {
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		.name = "wmi-bmof",
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	},
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	.probe = wmi_bmof_probe,
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	.remove = wmi_bmof_remove,
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	.id_table = wmi_bmof_id_table,
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};
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module_wmi_driver(wmi_bmof_driver);
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MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);
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MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
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MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
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MODULE_LICENSE("GPL");
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