ambakmi.c revision aa25afad2ca60d19457849ea75e9c31236f4e174 
1/*
2 *  linux/drivers/input/serio/ambakmi.c
3 *
4 *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
5 *  Copyright (C) 2002 Russell King.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/serio.h>
15#include <linux/errno.h>
16#include <linux/interrupt.h>
17#include <linux/ioport.h>
18#include <linux/device.h>
19#include <linux/delay.h>
20#include <linux/slab.h>
21#include <linux/err.h>
22#include <linux/amba/bus.h>
23#include <linux/amba/kmi.h>
24#include <linux/clk.h>
25
26#include <asm/io.h>
27#include <asm/irq.h>
28
29#define KMI_BASE	(kmi->base)
30
31struct amba_kmi_port {
32	struct serio		*io;
33	struct clk		*clk;
34	void __iomem		*base;
35	unsigned int		irq;
36	unsigned int		divisor;
37	unsigned int		open;
38};
39
40static irqreturn_t amba_kmi_int(int irq, void *dev_id)
41{
42	struct amba_kmi_port *kmi = dev_id;
43	unsigned int status = readb(KMIIR);
44	int handled = IRQ_NONE;
45
46	while (status & KMIIR_RXINTR) {
47		serio_interrupt(kmi->io, readb(KMIDATA), 0);
48		status = readb(KMIIR);
49		handled = IRQ_HANDLED;
50	}
51
52	return handled;
53}
54
55static int amba_kmi_write(struct serio *io, unsigned char val)
56{
57	struct amba_kmi_port *kmi = io->port_data;
58	unsigned int timeleft = 10000; /* timeout in 100ms */
59
60	while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
61		udelay(10);
62
63	if (timeleft)
64		writeb(val, KMIDATA);
65
66	return timeleft ? 0 : SERIO_TIMEOUT;
67}
68
69static int amba_kmi_open(struct serio *io)
70{
71	struct amba_kmi_port *kmi = io->port_data;
72	unsigned int divisor;
73	int ret;
74
75	ret = clk_enable(kmi->clk);
76	if (ret)
77		goto out;
78
79	divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
80	writeb(divisor, KMICLKDIV);
81	writeb(KMICR_EN, KMICR);
82
83	ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi);
84	if (ret) {
85		printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
86		writeb(0, KMICR);
87		goto clk_disable;
88	}
89
90	writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
91
92	return 0;
93
94 clk_disable:
95	clk_disable(kmi->clk);
96 out:
97	return ret;
98}
99
100static void amba_kmi_close(struct serio *io)
101{
102	struct amba_kmi_port *kmi = io->port_data;
103
104	writeb(0, KMICR);
105
106	free_irq(kmi->irq, kmi);
107	clk_disable(kmi->clk);
108}
109
110static int __devinit amba_kmi_probe(struct amba_device *dev,
111	const struct amba_id *id)
112{
113	struct amba_kmi_port *kmi;
114	struct serio *io;
115	int ret;
116
117	ret = amba_request_regions(dev, NULL);
118	if (ret)
119		return ret;
120
121	kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
122	io = kzalloc(sizeof(struct serio), GFP_KERNEL);
123	if (!kmi || !io) {
124		ret = -ENOMEM;
125		goto out;
126	}
127
128
129	io->id.type	= SERIO_8042;
130	io->write	= amba_kmi_write;
131	io->open	= amba_kmi_open;
132	io->close	= amba_kmi_close;
133	strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name));
134	strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
135	io->port_data	= kmi;
136	io->dev.parent	= &dev->dev;
137
138	kmi->io		= io;
139	kmi->base	= ioremap(dev->res.start, resource_size(&dev->res));
140	if (!kmi->base) {
141		ret = -ENOMEM;
142		goto out;
143	}
144
145	kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
146	if (IS_ERR(kmi->clk)) {
147		ret = PTR_ERR(kmi->clk);
148		goto unmap;
149	}
150
151	kmi->irq = dev->irq[0];
152	amba_set_drvdata(dev, kmi);
153
154	serio_register_port(kmi->io);
155	return 0;
156
157 unmap:
158	iounmap(kmi->base);
159 out:
160	kfree(kmi);
161	kfree(io);
162	amba_release_regions(dev);
163	return ret;
164}
165
166static int __devexit amba_kmi_remove(struct amba_device *dev)
167{
168	struct amba_kmi_port *kmi = amba_get_drvdata(dev);
169
170	amba_set_drvdata(dev, NULL);
171
172	serio_unregister_port(kmi->io);
173	clk_put(kmi->clk);
174	iounmap(kmi->base);
175	kfree(kmi);
176	amba_release_regions(dev);
177	return 0;
178}
179
180static int amba_kmi_resume(struct amba_device *dev)
181{
182	struct amba_kmi_port *kmi = amba_get_drvdata(dev);
183
184	/* kick the serio layer to rescan this port */
185	serio_reconnect(kmi->io);
186
187	return 0;
188}
189
190static struct amba_id amba_kmi_idtable[] = {
191	{
192		.id	= 0x00041050,
193		.mask	= 0x000fffff,
194	},
195	{ 0, 0 }
196};
197
198static struct amba_driver ambakmi_driver = {
199	.drv		= {
200		.name	= "kmi-pl050",
201		.owner	= THIS_MODULE,
202	},
203	.id_table	= amba_kmi_idtable,
204	.probe		= amba_kmi_probe,
205	.remove		= __devexit_p(amba_kmi_remove),
206	.resume		= amba_kmi_resume,
207};
208
209static int __init amba_kmi_init(void)
210{
211	return amba_driver_register(&ambakmi_driver);
212}
213
214static void __exit amba_kmi_exit(void)
215{
216	amba_driver_unregister(&ambakmi_driver);
217}
218
219module_init(amba_kmi_init);
220module_exit(amba_kmi_exit);
221
222MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
223MODULE_DESCRIPTION("AMBA KMI controller driver");
224MODULE_LICENSE("GPL");
225