1/*
2 * Altera University Program PS2 controller driver
3 *
4 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
5 *
6 * Based on sa1111ps2.c, which is:
7 * Copyright (C) 2002 Russell King
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/module.h>
15#include <linux/input.h>
16#include <linux/serio.h>
17#include <linux/interrupt.h>
18#include <linux/platform_device.h>
19#include <linux/io.h>
20#include <linux/slab.h>
21#include <linux/of.h>
22
23#define DRV_NAME "altera_ps2"
24
25struct ps2if {
26 struct serio *io;
27 void __iomem *base;
28};
29
30/*
31 * Read all bytes waiting in the PS2 port. There should be
32 * at the most one, but we loop for safety.
33 */
34static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
35{
36 struct ps2if *ps2if = dev_id;
37 unsigned int status;
38 irqreturn_t handled = IRQ_NONE;
39
40 while ((status = readl(ps2if->base)) & 0xffff0000) {
41 serio_interrupt(ps2if->io, status & 0xff, 0);
42 handled = IRQ_HANDLED;
43 }
44
45 return handled;
46}
47
48/*
49 * Write a byte to the PS2 port.
50 */
51static int altera_ps2_write(struct serio *io, unsigned char val)
52{
53 struct ps2if *ps2if = io->port_data;
54
55 writel(val, ps2if->base);
56 return 0;
57}
58
59static int altera_ps2_open(struct serio *io)
60{
61 struct ps2if *ps2if = io->port_data;
62
63 /* clear fifo */
64 while (readl(ps2if->base) & 0xffff0000)
65 /* empty */;
66
67 writel(1, ps2if->base + 4); /* enable rx irq */
68 return 0;
69}
70
71static void altera_ps2_close(struct serio *io)
72{
73 struct ps2if *ps2if = io->port_data;
74
75 writel(0, ps2if->base + 4); /* disable rx irq */
76}
77
78/*
79 * Add one device to this driver.
80 */
81static int altera_ps2_probe(struct platform_device *pdev)
82{
83 struct ps2if *ps2if;
84 struct resource *res;
85 struct serio *serio;
86 int error, irq;
87
88 ps2if = devm_kzalloc(&pdev->dev, sizeof(struct ps2if), GFP_KERNEL);
89 if (!ps2if)
90 return -ENOMEM;
91
92 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
93 ps2if->base = devm_ioremap_resource(&pdev->dev, res);
94 if (IS_ERR(ps2if->base))
95 return PTR_ERR(ps2if->base);
96
97 irq = platform_get_irq(pdev, 0);
98 if (irq < 0)
99 return -ENXIO;
100
101 error = devm_request_irq(&pdev->dev, irq, altera_ps2_rxint, 0,
102 pdev->name, ps2if);
103 if (error) {
104 dev_err(&pdev->dev, "could not request IRQ %d\n", irq);
105 return error;
106 }
107
108 serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
109 if (!serio)
110 return -ENOMEM;
111
112 serio->id.type = SERIO_8042;
113 serio->write = altera_ps2_write;
114 serio->open = altera_ps2_open;
115 serio->close = altera_ps2_close;
116 strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
117 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
118 serio->port_data = ps2if;
119 serio->dev.parent = &pdev->dev;
120 ps2if->io = serio;
121
122 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, irq);
123
124 serio_register_port(ps2if->io);
125 platform_set_drvdata(pdev, ps2if);
126
127 return 0;
128}
129
130/*
131 * Remove one device from this driver.
132 */
133static int altera_ps2_remove(struct platform_device *pdev)
134{
135 struct ps2if *ps2if = platform_get_drvdata(pdev);
136
137 serio_unregister_port(ps2if->io);
138
139 return 0;
140}
141
142#ifdef CONFIG_OF
143static const struct of_device_id altera_ps2_match[] = {
144 { .compatible = "ALTR,ps2-1.0", },
145 { .compatible = "altr,ps2-1.0", },
146 {},
147};
148MODULE_DEVICE_TABLE(of, altera_ps2_match);
149#endif /* CONFIG_OF */
150
151/*
152 * Our device driver structure
153 */
154static struct platform_driver altera_ps2_driver = {
155 .probe = altera_ps2_probe,
156 .remove = altera_ps2_remove,
157 .driver = {
158 .name = DRV_NAME,
159 .of_match_table = of_match_ptr(altera_ps2_match),
160 },
161};
162module_platform_driver(altera_ps2_driver);
163
164MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
165MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
166MODULE_LICENSE("GPL");
167MODULE_ALIAS("platform:" DRV_NAME);
168