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(serio: port, data: byte, flags: 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(irq: rpckbd->rx_irq, handler: rpckbd_rx, flags: 0, name: "rpckbd", dev: port) != 0) {
72 printk(KERN_ERR "rpckbd.c: Could not allocate keyboard receive IRQ\n");
73 return -EBUSY;
74 }
75
76 if (request_irq(irq: rpckbd->tx_irq, handler: rpckbd_tx, flags: 0, name: "rpckbd", dev: 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(*serio), GFP_KERNEL);
112 rpckbd = kzalloc(sizeof(*rpckbd), GFP_KERNEL);
113 if (!serio || !rpckbd) {
114 kfree(objp: rpckbd);
115 kfree(objp: 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(pdev: dev, data: 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(pdev: dev);
139 struct rpckbd_data *rpckbd = serio->port_data;
140
141 serio_unregister_port(serio);
142 kfree(objp: rpckbd);
143}
144
145static struct platform_driver rpckbd_driver = {
146 .probe = rpckbd_probe,
147 .remove = rpckbd_remove,
148 .driver = {
149 .name = "kart",
150 },
151};
152module_platform_driver(rpckbd_driver);
153

source code of linux/drivers/input/serio/rpckbd.c