1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Copyright (c) 2000-2001 Vojtech Pavlik
4 *  Copyright (c) 2002 Russell King
5 */
6
7/*
8 * Acorn RiscPC PS/2 keyboard controller driver for Linux/ARM
9 */
10
11#include <linux/module.h>
12#include <linux/interrupt.h>
13#include <linux/serio.h>
14#include <linux/err.h>
15#include <linux/platform_device.h>
16#include <linux/io.h>
17#include <linux/slab.h>
18
19#include <mach/hardware.h>
20#include <asm/hardware/iomd.h>
21
22MODULE_AUTHOR("Vojtech Pavlik, Russell King");
23MODULE_DESCRIPTION("Acorn RiscPC PS/2 keyboard controller driver");
24MODULE_LICENSE("GPL");
25MODULE_ALIAS("platform:kart");
26
27struct rpckbd_data {
28	int tx_irq;
29	int rx_irq;
30};
31
32static int rpckbd_write(struct serio *port, unsigned char val)
33{
34	while (!(iomd_readb(IOMD_KCTRL) & (1 << 7)))
35		cpu_relax();
36
37	iomd_writeb(val, IOMD_KARTTX);
38
39	return 0;
40}
41
42static irqreturn_t rpckbd_rx(int irq, void *dev_id)
43{
44	struct serio *port = dev_id;
45	unsigned int byte;
46	int handled = IRQ_NONE;
47
48	while (iomd_readb(IOMD_KCTRL) & (1 << 5)) {
49		byte = iomd_readb(IOMD_KARTRX);
50
51		serio_interrupt(port, byte, 0);
52		handled = IRQ_HANDLED;
53	}
54	return handled;
55}
56
57static irqreturn_t rpckbd_tx(int irq, void *dev_id)
58{
59	return IRQ_HANDLED;
60}
61
62static int rpckbd_open(struct serio *port)
63{
64	struct rpckbd_data *rpckbd = port->port_data;
65
66	/* Reset the keyboard state machine. */
67	iomd_writeb(0, IOMD_KCTRL);
68	iomd_writeb(8, IOMD_KCTRL);
69	iomd_readb(IOMD_KARTRX);
70
71	if (request_irq(rpckbd->rx_irq, rpckbd_rx, 0, "rpckbd", port) != 0) {
72		printk(KERN_ERR "rpckbd.c: Could not allocate keyboard receive IRQ\n");
73		return -EBUSY;
74	}
75
76	if (request_irq(rpckbd->tx_irq, rpckbd_tx, 0, "rpckbd", port) != 0) {
77		printk(KERN_ERR "rpckbd.c: Could not allocate keyboard transmit IRQ\n");
78		free_irq(rpckbd->rx_irq, port);
79		return -EBUSY;
80	}
81
82	return 0;
83}
84
85static void rpckbd_close(struct serio *port)
86{
87	struct rpckbd_data *rpckbd = port->port_data;
88
89	free_irq(rpckbd->rx_irq, port);
90	free_irq(rpckbd->tx_irq, port);
91}
92
93/*
94 * Allocate and initialize serio structure for subsequent registration
95 * with serio core.
96 */
97static int rpckbd_probe(struct platform_device *dev)
98{
99	struct rpckbd_data *rpckbd;
100	struct serio *serio;
101	int tx_irq, rx_irq;
102
103	rx_irq = platform_get_irq(dev, 0);
104	if (rx_irq < 0)
105		return rx_irq;
106
107	tx_irq = platform_get_irq(dev, 1);
108	if (tx_irq < 0)
109		return tx_irq;
110
111	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
112	rpckbd = kzalloc(sizeof(*rpckbd), GFP_KERNEL);
113	if (!serio || !rpckbd) {
114		kfree(rpckbd);
115		kfree(serio);
116		return -ENOMEM;
117	}
118
119	rpckbd->rx_irq = rx_irq;
120	rpckbd->tx_irq = tx_irq;
121
122	serio->id.type		= SERIO_8042;
123	serio->write		= rpckbd_write;
124	serio->open		= rpckbd_open;
125	serio->close		= rpckbd_close;
126	serio->dev.parent	= &dev->dev;
127	serio->port_data	= rpckbd;
128	strscpy(serio->name, "RiscPC PS/2 kbd port", sizeof(serio->name));
129	strscpy(serio->phys, "rpckbd/serio0", sizeof(serio->phys));
130
131	platform_set_drvdata(dev, serio);
132	serio_register_port(serio);
133	return 0;
134}
135
136static void rpckbd_remove(struct platform_device *dev)
137{
138	struct serio *serio = platform_get_drvdata(dev);
139	struct rpckbd_data *rpckbd = serio->port_data;
140
141	serio_unregister_port(serio);
142	kfree(rpckbd);
143}
144
145static struct platform_driver rpckbd_driver = {
146	.probe		= rpckbd_probe,
147	.remove_new	= rpckbd_remove,
148	.driver		= {
149		.name	= "kart",
150	},
151};
152module_platform_driver(rpckbd_driver);
153