aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/serio/altera_ps2.c
blob: 35864c6130bb0b5723eed9f2fcc8408868f36bef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/*
 * Altera University Program PS2 controller driver
 *
 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
 *
 * Based on sa1111ps2.c, which is:
 * Copyright (C) 2002 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>

#define DRV_NAME "altera_ps2"

struct ps2if {
	struct serio *io;
	struct resource *iomem_res;
	void __iomem *base;
	unsigned irq;
};

/*
 * Read all bytes waiting in the PS2 port.  There should be
 * at the most one, but we loop for safety.
 */
static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
{
	struct ps2if *ps2if = dev_id;
	unsigned int status;
	int handled = IRQ_NONE;

	while ((status = readl(ps2if->base)) & 0xffff0000) {
		serio_interrupt(ps2if->io, status & 0xff, 0);
		handled = IRQ_HANDLED;
	}

	return handled;
}

/*
 * Write a byte to the PS2 port.
 */
static int altera_ps2_write(struct serio *io, unsigned char val)
{
	struct ps2if *ps2if = io->port_data;

	writel(val, ps2if->base);
	return 0;
}

static int altera_ps2_open(struct serio *io)
{
	struct ps2if *ps2if = io->port_data;

	/* clear fifo */
	while (readl(ps2if->base) & 0xffff0000)
		/* empty */;

	writel(1, ps2if->base + 4); /* enable rx irq */
	return 0;
}

static void altera_ps2_close(struct serio *io)
{
	struct ps2if *ps2if = io->port_data;

	writel(0, ps2if->base); /* disable rx irq */
}

/*
 * Add one device to this driver.
 */
static int __devinit altera_ps2_probe(struct platform_device *pdev)
{
	struct ps2if *ps2if;
	struct serio *serio;
	int error, irq;

	ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!ps2if || !serio) {
		error = -ENOMEM;
		goto err_free_mem;
	}

	serio->id.type		= SERIO_8042;
	serio->write		= altera_ps2_write;
	serio->open		= altera_ps2_open;
	serio->close		= altera_ps2_close;
	strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
	strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
	serio->port_data	= ps2if;
	serio->dev.parent	= &pdev->dev;
	ps2if->io		= serio;

	ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (ps2if->iomem_res == NULL) {
		error = -ENOENT;
		goto err_free_mem;
	}


	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		error = -ENXIO;
		goto err_free_mem;
	}
	ps2if->irq = irq;

	if (!request_mem_region(ps2if->iomem_res->start,
				resource_size(ps2if->iomem_res), pdev->name)) {
		error = -EBUSY;
		goto err_free_mem;
	}

	ps2if->base = ioremap(ps2if->iomem_res->start,
			      resource_size(ps2if->iomem_res));
	if (!ps2if->base) {
		error = -ENOMEM;
		goto err_free_res;
	}

	error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if);
	if (error) {
		dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n",
			ps2if->irq, error);
		goto err_unmap;
	}

	dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq);

	serio_register_port(ps2if->io);
	platform_set_drvdata(pdev, ps2if);

	return 0;

 err_unmap:
	iounmap(ps2if->base);
 err_free_res:
	release_mem_region(ps2if->iomem_res->start,
			   resource_size(ps2if->iomem_res));
 err_free_mem:
	kfree(ps2if);
	kfree(serio);
	return error;
}

/*
 * Remove one device from this driver.
 */
static int __devexit altera_ps2_remove(struct platform_device *pdev)
{
	struct ps2if *ps2if = platform_get_drvdata(pdev);

	platform_set_drvdata(pdev, NULL);
	serio_unregister_port(ps2if->io);
	free_irq(ps2if->irq, ps2if);
	iounmap(ps2if->base);
	release_mem_region(ps2if->iomem_res->start,
			   resource_size(ps2if->iomem_res));
	kfree(ps2if);

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id altera_ps2_match[] = {
	{ .compatible = "ALTR,ps2-1.0", },
	{},
};
MODULE_DEVICE_TABLE(of, altera_ps2_match);
#else /* CONFIG_OF */
#define altera_ps2_match NULL
#endif /* CONFIG_OF */

/*
 * Our device driver structure
 */
static struct platform_driver altera_ps2_driver = {
	.probe		= altera_ps2_probe,
	.remove		= __devexit_p(altera_ps2_remove),
	.driver	= {
		.name	= DRV_NAME,
		.owner	= THIS_MODULE,
		.of_match_table = altera_ps2_match,
	},
};
module_platform_driver(altera_ps2_driver);

MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);