cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xo15-ebook.c (3835B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  OLPC XO-1.5 ebook switch driver
      4 *  (based on generic ACPI button driver)
      5 *
      6 *  Copyright (C) 2009 Paul Fox <pgf@laptop.org>
      7 *  Copyright (C) 2010 One Laptop per Child
      8 */
      9
     10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
     11
     12#include <linux/kernel.h>
     13#include <linux/module.h>
     14#include <linux/init.h>
     15#include <linux/types.h>
     16#include <linux/input.h>
     17#include <linux/acpi.h>
     18
     19#define MODULE_NAME "xo15-ebook"
     20
     21#define XO15_EBOOK_CLASS		MODULE_NAME
     22#define XO15_EBOOK_TYPE_UNKNOWN	0x00
     23#define XO15_EBOOK_NOTIFY_STATUS	0x80
     24
     25#define XO15_EBOOK_SUBCLASS		"ebook"
     26#define XO15_EBOOK_HID			"XO15EBK"
     27#define XO15_EBOOK_DEVICE_NAME		"EBook Switch"
     28
     29MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
     30MODULE_LICENSE("GPL");
     31
     32static const struct acpi_device_id ebook_device_ids[] = {
     33	{ XO15_EBOOK_HID, 0 },
     34	{ "", 0 },
     35};
     36MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
     37
     38struct ebook_switch {
     39	struct input_dev *input;
     40	char phys[32];			/* for input device */
     41};
     42
     43static int ebook_send_state(struct acpi_device *device)
     44{
     45	struct ebook_switch *button = acpi_driver_data(device);
     46	unsigned long long state;
     47	acpi_status status;
     48
     49	status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state);
     50	if (ACPI_FAILURE(status))
     51		return -EIO;
     52
     53	/* input layer checks if event is redundant */
     54	input_report_switch(button->input, SW_TABLET_MODE, !state);
     55	input_sync(button->input);
     56	return 0;
     57}
     58
     59static void ebook_switch_notify(struct acpi_device *device, u32 event)
     60{
     61	switch (event) {
     62	case ACPI_FIXED_HARDWARE_EVENT:
     63	case XO15_EBOOK_NOTIFY_STATUS:
     64		ebook_send_state(device);
     65		break;
     66	default:
     67		acpi_handle_debug(device->handle,
     68				  "Unsupported event [0x%x]\n", event);
     69		break;
     70	}
     71}
     72
     73#ifdef CONFIG_PM_SLEEP
     74static int ebook_switch_resume(struct device *dev)
     75{
     76	return ebook_send_state(to_acpi_device(dev));
     77}
     78#endif
     79
     80static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
     81
     82static int ebook_switch_add(struct acpi_device *device)
     83{
     84	struct ebook_switch *button;
     85	struct input_dev *input;
     86	const char *hid = acpi_device_hid(device);
     87	char *name, *class;
     88	int error;
     89
     90	button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
     91	if (!button)
     92		return -ENOMEM;
     93
     94	device->driver_data = button;
     95
     96	button->input = input = input_allocate_device();
     97	if (!input) {
     98		error = -ENOMEM;
     99		goto err_free_button;
    100	}
    101
    102	name = acpi_device_name(device);
    103	class = acpi_device_class(device);
    104
    105	if (strcmp(hid, XO15_EBOOK_HID)) {
    106		pr_err("Unsupported hid [%s]\n", hid);
    107		error = -ENODEV;
    108		goto err_free_input;
    109	}
    110
    111	strcpy(name, XO15_EBOOK_DEVICE_NAME);
    112	sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS);
    113
    114	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
    115
    116	input->name = name;
    117	input->phys = button->phys;
    118	input->id.bustype = BUS_HOST;
    119	input->dev.parent = &device->dev;
    120
    121	input->evbit[0] = BIT_MASK(EV_SW);
    122	set_bit(SW_TABLET_MODE, input->swbit);
    123
    124	error = input_register_device(input);
    125	if (error)
    126		goto err_free_input;
    127
    128	ebook_send_state(device);
    129
    130	if (device->wakeup.flags.valid) {
    131		/* Button's GPE is run-wake GPE */
    132		acpi_enable_gpe(device->wakeup.gpe_device,
    133				device->wakeup.gpe_number);
    134		device_set_wakeup_enable(&device->dev, true);
    135	}
    136
    137	return 0;
    138
    139 err_free_input:
    140	input_free_device(input);
    141 err_free_button:
    142	kfree(button);
    143	return error;
    144}
    145
    146static int ebook_switch_remove(struct acpi_device *device)
    147{
    148	struct ebook_switch *button = acpi_driver_data(device);
    149
    150	input_unregister_device(button->input);
    151	kfree(button);
    152	return 0;
    153}
    154
    155static struct acpi_driver xo15_ebook_driver = {
    156	.name = MODULE_NAME,
    157	.class = XO15_EBOOK_CLASS,
    158	.ids = ebook_device_ids,
    159	.ops = {
    160		.add = ebook_switch_add,
    161		.remove = ebook_switch_remove,
    162		.notify = ebook_switch_notify,
    163	},
    164	.drv.pm = &ebook_switch_pm,
    165};
    166module_acpi_driver(xo15_ebook_driver);