xo15-ebook.c

  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	const struct acpi_device_id *id;
 85	struct ebook_switch *button;
 86	struct input_dev *input;
 87	int error;
 88
 89	button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
 90	if (!button)
 91		return -ENOMEM;
 92
 93	device->driver_data = button;
 94
 95	button->input = input = input_allocate_device();
 96	if (!input) {
 97		error = -ENOMEM;
 98		goto err_free_button;
 99	}
100
101	id = acpi_match_acpi_device(ebook_device_ids, device);
102	if (!id) {
103		dev_err(&device->dev, "Unsupported hid\n");
104		error = -ENODEV;
105		goto err_free_input;
106	}
107
108	strscpy(acpi_device_name(device), XO15_EBOOK_DEVICE_NAME);
109	strscpy(acpi_device_class(device), XO15_EBOOK_CLASS "/" XO15_EBOOK_SUBCLASS);
110
111	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", id->id);
112
113	input->name = acpi_device_name(device);
114	input->phys = button->phys;
115	input->id.bustype = BUS_HOST;
116	input->dev.parent = &device->dev;
117
118	input->evbit[0] = BIT_MASK(EV_SW);
119	set_bit(SW_TABLET_MODE, input->swbit);
120
121	error = input_register_device(input);
122	if (error)
123		goto err_free_input;
124
125	ebook_send_state(device);
126
127	if (device->wakeup.flags.valid) {
128		/* Button's GPE is run-wake GPE */
129		acpi_enable_gpe(device->wakeup.gpe_device,
130				device->wakeup.gpe_number);
131		device_set_wakeup_enable(&device->dev, true);
132	}
133
134	return 0;
135
136 err_free_input:
137	input_free_device(input);
138 err_free_button:
139	kfree(button);
140	return error;
141}
142
143static void ebook_switch_remove(struct acpi_device *device)
144{
145	struct ebook_switch *button = acpi_driver_data(device);
146
147	input_unregister_device(button->input);
148	kfree(button);
149}
150
151static struct acpi_driver xo15_ebook_driver = {
152	.name = MODULE_NAME,
153	.class = XO15_EBOOK_CLASS,
154	.ids = ebook_device_ids,
155	.ops = {
156		.add = ebook_switch_add,
157		.remove = ebook_switch_remove,
158		.notify = ebook_switch_notify,
159	},
160	.drv.pm = &ebook_switch_pm,
161};
162module_acpi_driver(xo15_ebook_driver);