1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  linux/drivers/input/serio/ambakmi.c
4 *
5 *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
6 *  Copyright (C) 2002 Russell King.
7 */
8#include <linux/module.h>
9#include <linux/serio.h>
10#include <linux/errno.h>
11#include <linux/interrupt.h>
12#include <linux/ioport.h>
13#include <linux/device.h>
14#include <linux/delay.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/amba/bus.h>
18#include <linux/amba/kmi.h>
19#include <linux/clk.h>
20
21#include <asm/io.h>
22#include <asm/irq.h>
23
24#define KMI_BASE	(kmi->base)
25
26struct amba_kmi_port {
27	struct serio		*io;
28	struct clk		*clk;
29	void __iomem		*base;
30	unsigned int		irq;
31	unsigned int		divisor;
32	unsigned int		open;
33};
34
35static irqreturn_t amba_kmi_int(int irq, void *dev_id)
36{
37	struct amba_kmi_port *kmi = dev_id;
38	unsigned int status = readb(KMIIR);
39	int handled = IRQ_NONE;
40
41	while (status & KMIIR_RXINTR) {
42		serio_interrupt(kmi->io, readb(KMIDATA), 0);
43		status = readb(KMIIR);
44		handled = IRQ_HANDLED;
45	}
46
47	return handled;
48}
49
50static int amba_kmi_write(struct serio *io, unsigned char val)
51{
52	struct amba_kmi_port *kmi = io->port_data;
53	unsigned int timeleft = 10000; /* timeout in 100ms */
54
55	while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
56		udelay(10);
57
58	if (timeleft)
59		writeb(val, KMIDATA);
60
61	return timeleft ? 0 : SERIO_TIMEOUT;
62}
63
64static int amba_kmi_open(struct serio *io)
65{
66	struct amba_kmi_port *kmi = io->port_data;
67	unsigned int divisor;
68	int ret;
69
70	ret = clk_prepare_enable(kmi->clk);
71	if (ret)
72		goto out;
73
74	divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
75	writeb(divisor, KMICLKDIV);
76	writeb(KMICR_EN, KMICR);
77
78	ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050",
79			  kmi);
80	if (ret) {
81		printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
82		writeb(0, KMICR);
83		goto clk_disable;
84	}
85
86	writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
87
88	return 0;
89
90 clk_disable:
91	clk_disable_unprepare(kmi->clk);
92 out:
93	return ret;
94}
95
96static void amba_kmi_close(struct serio *io)
97{
98	struct amba_kmi_port *kmi = io->port_data;
99
100	writeb(0, KMICR);
101
102	free_irq(kmi->irq, kmi);
103	clk_disable_unprepare(kmi->clk);
104}
105
106static int amba_kmi_probe(struct amba_device *dev,
107	const struct amba_id *id)
108{
109	struct amba_kmi_port *kmi;
110	struct serio *io;
111	int ret;
112
113	ret = amba_request_regions(dev, NULL);
114	if (ret)
115		return ret;
116
117	kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
118	io = kzalloc(sizeof(struct serio), GFP_KERNEL);
119	if (!kmi || !io) {
120		ret = -ENOMEM;
121		goto out;
122	}
123
124
125	io->id.type	= SERIO_8042;
126	io->write	= amba_kmi_write;
127	io->open	= amba_kmi_open;
128	io->close	= amba_kmi_close;
129	strscpy(io->name, dev_name(&dev->dev), sizeof(io->name));
130	strscpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
131	io->port_data	= kmi;
132	io->dev.parent	= &dev->dev;
133
134	kmi->io		= io;
135	kmi->base	= ioremap(dev->res.start, resource_size(&dev->res));
136	if (!kmi->base) {
137		ret = -ENOMEM;
138		goto out;
139	}
140
141	kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
142	if (IS_ERR(kmi->clk)) {
143		ret = PTR_ERR(kmi->clk);
144		goto unmap;
145	}
146
147	kmi->irq = dev->irq[0];
148	amba_set_drvdata(dev, kmi);
149
150	serio_register_port(kmi->io);
151	return 0;
152
153 unmap:
154	iounmap(kmi->base);
155 out:
156	kfree(kmi);
157	kfree(io);
158	amba_release_regions(dev);
159	return ret;
160}
161
162static void amba_kmi_remove(struct amba_device *dev)
163{
164	struct amba_kmi_port *kmi = amba_get_drvdata(dev);
165
166	serio_unregister_port(kmi->io);
167	clk_put(kmi->clk);
168	iounmap(kmi->base);
169	kfree(kmi);
170	amba_release_regions(dev);
171}
172
173static int amba_kmi_resume(struct device *dev)
174{
175	struct amba_kmi_port *kmi = dev_get_drvdata(dev);
176
177	/* kick the serio layer to rescan this port */
178	serio_reconnect(kmi->io);
179
180	return 0;
181}
182
183static DEFINE_SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
184
185static const struct amba_id amba_kmi_idtable[] = {
186	{
187		.id	= 0x00041050,
188		.mask	= 0x000fffff,
189	},
190	{ 0, 0 }
191};
192
193MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
194
195static struct amba_driver ambakmi_driver = {
196	.drv		= {
197		.name	= "kmi-pl050",
198		.owner	= THIS_MODULE,
199		.pm	= pm_sleep_ptr(&amba_kmi_dev_pm_ops),
200	},
201	.id_table	= amba_kmi_idtable,
202	.probe		= amba_kmi_probe,
203	.remove		= amba_kmi_remove,
204};
205
206module_amba_driver(ambakmi_driver);
207
208MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
209MODULE_DESCRIPTION("AMBA KMI controller driver");
210MODULE_LICENSE("GPL");
211