linux/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Functions corresponding to methods under BIOS interface GUID
 * for use with hp-bioscfg driver.
 *
 *  Copyright (c) 2022 Hewlett-Packard Inc.
 */

#include <linux/wmi.h>
#include "bioscfg.h"

/*
 * struct bios_args buffer is dynamically allocated.  New WMI command types
 * were introduced that exceeds 128-byte data size.  Changes to handle
 * the data size allocation scheme were kept in hp_wmi_perform_query function.
 */
struct bios_args { … };

/**
 * hp_set_attribute
 *
 * @a_name: The attribute name
 * @a_value: The attribute value
 *
 * Sets an attribute to new value
 *
 * Returns zero on success
 *	-ENODEV if device is not found
 *	-EINVAL if the instance of 'Setup Admin' password is not found.
 *	-ENOMEM unable to allocate memory
 */
int hp_set_attribute(const char *a_name, const char *a_value)
{ … }

/**
 * hp_wmi_perform_query
 *
 * @query:	The commandtype (enum hp_wmi_commandtype)
 * @command:	The command (enum hp_wmi_command)
 * @buffer:	Buffer used as input and/or output
 * @insize:	Size of input buffer
 * @outsize:	Size of output buffer
 *
 * returns zero on success
 *         an HP WMI query specific error code (which is positive)
 *         -EINVAL if the query was not successful at all
 *         -EINVAL if the output buffer size exceeds buffersize
 *
 * Note: The buffersize must at least be the maximum of the input and output
 *       size. E.g. Battery info query is defined to have 1 byte input
 *       and 128 byte output. The caller would do:
 *       buffer = kzalloc(128, GFP_KERNEL);
 *       ret = hp_wmi_perform_query(HPWMI_BATTERY_QUERY, HPWMI_READ,
 *				    buffer, 1, 128)
 */
int hp_wmi_perform_query(int query, enum hp_wmi_command command, void *buffer,
			 u32 insize, u32 outsize)
{ … }

static void *utf16_empty_string(u16 *p)
{ … }

/**
 * hp_ascii_to_utf16_unicode -  Convert ascii string to UTF-16 unicode
 *
 * BIOS supports UTF-16 characters that are 2 bytes long.  No variable
 * multi-byte language supported.
 *
 * @p:   Unicode buffer address
 * @str: string to convert to unicode
 *
 * Returns a void pointer to the buffer string
 */
void *hp_ascii_to_utf16_unicode(u16 *p, const u8 *str)
{ … }

/**
 * hp_wmi_set_bios_setting - Set setting's value in BIOS
 *
 * @input_buffer: Input buffer address
 * @input_size:   Input buffer size
 *
 * Returns: Count of unicode characters written to BIOS if successful, otherwise
 *		-ENOMEM unable to allocate memory
 *		-EINVAL buffer not allocated or too small
 */
int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
{ … }

static int hp_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
{ … }

static void hp_attr_set_interface_remove(struct wmi_device *wdev)
{ … }

static const struct wmi_device_id hp_attr_set_interface_id_table[] = …;

static struct wmi_driver hp_attr_set_interface_driver = …;

int hp_init_attr_set_interface(void)
{ … }

void hp_exit_attr_set_interface(void)
{ … }

MODULE_DEVICE_TABLE(wmi, hp_attr_set_interface_id_table);