1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2007 Google, Inc.
4 * Copyright (C) 2012 Intel, Inc.
5 */
6
7#include <linux/module.h>
8#include <linux/interrupt.h>
9#include <linux/types.h>
10#include <linux/input.h>
11#include <linux/kernel.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/irq.h>
15#include <linux/io.h>
16#include <linux/acpi.h>
17
18enum {
19	REG_READ        = 0x00,
20	REG_SET_PAGE    = 0x00,
21	REG_LEN         = 0x04,
22	REG_DATA        = 0x08,
23
24	PAGE_NAME       = 0x00000,
25	PAGE_EVBITS     = 0x10000,
26	PAGE_ABSDATA    = 0x20000 | EV_ABS,
27};
28
29struct event_dev {
30	struct input_dev *input;
31	int irq;
32	void __iomem *addr;
33	char name[];
34};
35
36static irqreturn_t events_interrupt(int irq, void *dev_id)
37{
38	struct event_dev *edev = dev_id;
39	unsigned int type, code, value;
40
41	type = __raw_readl(edev->addr + REG_READ);
42	code = __raw_readl(edev->addr + REG_READ);
43	value = __raw_readl(edev->addr + REG_READ);
44
45	input_event(edev->input, type, code, value);
46	input_sync(edev->input);
47	return IRQ_HANDLED;
48}
49
50static void events_import_bits(struct event_dev *edev,
51			unsigned long bits[], unsigned int type, size_t count)
52{
53	void __iomem *addr = edev->addr;
54	int i, j;
55	size_t size;
56	uint8_t val;
57
58	__raw_writel(PAGE_EVBITS | type, addr + REG_SET_PAGE);
59
60	size = __raw_readl(addr + REG_LEN) * 8;
61	if (size < count)
62		count = size;
63
64	addr += REG_DATA;
65	for (i = 0; i < count; i += 8) {
66		val = __raw_readb(addr++);
67		for (j = 0; j < 8; j++)
68			if (val & 1 << j)
69				set_bit(i + j, bits);
70	}
71}
72
73static void events_import_abs_params(struct event_dev *edev)
74{
75	struct input_dev *input_dev = edev->input;
76	void __iomem *addr = edev->addr;
77	u32 val[4];
78	int count;
79	int i, j;
80
81	__raw_writel(PAGE_ABSDATA, addr + REG_SET_PAGE);
82
83	count = __raw_readl(addr + REG_LEN) / sizeof(val);
84	if (count > ABS_MAX)
85		count = ABS_MAX;
86
87	for (i = 0; i < count; i++) {
88		if (!test_bit(i, input_dev->absbit))
89			continue;
90
91		for (j = 0; j < ARRAY_SIZE(val); j++) {
92			int offset = (i * ARRAY_SIZE(val) + j) * sizeof(u32);
93
94			val[j] = __raw_readl(edev->addr + REG_DATA + offset);
95		}
96
97		input_set_abs_params(input_dev, i,
98				     val[0], val[1], val[2], val[3]);
99	}
100}
101
102static int events_probe(struct platform_device *pdev)
103{
104	struct input_dev *input_dev;
105	struct event_dev *edev;
106	struct resource *res;
107	unsigned int keymapnamelen;
108	void __iomem *addr;
109	int irq;
110	int i;
111	int error;
112
113	irq = platform_get_irq(pdev, 0);
114	if (irq < 0)
115		return -EINVAL;
116
117	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
118	if (!res)
119		return -EINVAL;
120
121	addr = devm_ioremap(&pdev->dev, res->start, 4096);
122	if (!addr)
123		return -ENOMEM;
124
125	__raw_writel(PAGE_NAME, addr + REG_SET_PAGE);
126	keymapnamelen = __raw_readl(addr + REG_LEN);
127
128	edev = devm_kzalloc(&pdev->dev,
129			    sizeof(struct event_dev) + keymapnamelen + 1,
130			    GFP_KERNEL);
131	if (!edev)
132		return -ENOMEM;
133
134	input_dev = devm_input_allocate_device(&pdev->dev);
135	if (!input_dev)
136		return -ENOMEM;
137
138	edev->input = input_dev;
139	edev->addr = addr;
140	edev->irq = irq;
141
142	for (i = 0; i < keymapnamelen; i++)
143		edev->name[i] = __raw_readb(edev->addr + REG_DATA + i);
144
145	pr_debug("%s: keymap=%s\n", __func__, edev->name);
146
147	input_dev->name = edev->name;
148	input_dev->id.bustype = BUS_HOST;
149
150	events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);
151	events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);
152	events_import_bits(edev, input_dev->relbit, EV_REL, REL_MAX);
153	events_import_bits(edev, input_dev->absbit, EV_ABS, ABS_MAX);
154	events_import_bits(edev, input_dev->mscbit, EV_MSC, MSC_MAX);
155	events_import_bits(edev, input_dev->ledbit, EV_LED, LED_MAX);
156	events_import_bits(edev, input_dev->sndbit, EV_SND, SND_MAX);
157	events_import_bits(edev, input_dev->ffbit, EV_FF, FF_MAX);
158	events_import_bits(edev, input_dev->swbit, EV_SW, SW_MAX);
159
160	events_import_abs_params(edev);
161
162	error = devm_request_irq(&pdev->dev, edev->irq, events_interrupt, 0,
163				 "goldfish-events-keypad", edev);
164	if (error)
165		return error;
166
167	error = input_register_device(input_dev);
168	if (error)
169		return error;
170
171	return 0;
172}
173
174static const struct of_device_id goldfish_events_of_match[] = {
175	{ .compatible = "google,goldfish-events-keypad", },
176	{},
177};
178MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
179
180#ifdef CONFIG_ACPI
181static const struct acpi_device_id goldfish_events_acpi_match[] = {
182	{ "GFSH0002", 0 },
183	{ },
184};
185MODULE_DEVICE_TABLE(acpi, goldfish_events_acpi_match);
186#endif
187
188static struct platform_driver events_driver = {
189	.probe	= events_probe,
190	.driver	= {
191		.name	= "goldfish_events",
192		.of_match_table = goldfish_events_of_match,
193		.acpi_match_table = ACPI_PTR(goldfish_events_acpi_match),
194	},
195};
196
197module_platform_driver(events_driver);
198
199MODULE_AUTHOR("Brian Swetland");
200MODULE_DESCRIPTION("Goldfish Event Device");
201MODULE_LICENSE("GPL");
202