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 
18 enum {
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 
29 struct event_dev {
30 	struct input_dev *input;
31 	int irq;
32 	void __iomem *addr;
33 	char name[0];
34 };
35 
36 static 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 
50 static 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 
73 static 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 
102 static 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 
174 static const struct of_device_id goldfish_events_of_match[] = {
175 	{ .compatible = "google,goldfish-events-keypad", },
176 	{},
177 };
178 MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
179 
180 #ifdef CONFIG_ACPI
181 static const struct acpi_device_id goldfish_events_acpi_match[] = {
182 	{ "GFSH0002", 0 },
183 	{ },
184 };
185 MODULE_DEVICE_TABLE(acpi, goldfish_events_acpi_match);
186 #endif
187 
188 static 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 
197 module_platform_driver(events_driver);
198 
199 MODULE_AUTHOR("Brian Swetland");
200 MODULE_DESCRIPTION("Goldfish Event Device");
201 MODULE_LICENSE("GPL");
202