1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Copyright (c) 1999-2001 Vojtech Pavlik
4 */
5
6/*
7 *  82C710 C&T mouse port chip driver for Linux
8 */
9
10#include <linux/delay.h>
11#include <linux/module.h>
12#include <linux/ioport.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/serio.h>
16#include <linux/errno.h>
17#include <linux/err.h>
18#include <linux/platform_device.h>
19#include <linux/slab.h>
20
21#include <asm/io.h>
22
23MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
24MODULE_DESCRIPTION("82C710 C&T mouse port chip driver");
25MODULE_LICENSE("GPL");
26
27/*
28 * ct82c710 interface
29 */
30
31#define CT82C710_DEV_IDLE     0x01		/* Device Idle */
32#define CT82C710_RX_FULL      0x02		/* Device Char received */
33#define CT82C710_TX_IDLE      0x04		/* Device XMIT Idle */
34#define CT82C710_RESET        0x08		/* Device Reset */
35#define CT82C710_INTS_ON      0x10		/* Device Interrupt On */
36#define CT82C710_ERROR_FLAG   0x20		/* Device Error */
37#define CT82C710_CLEAR        0x40		/* Device Clear */
38#define CT82C710_ENABLE       0x80		/* Device Enable */
39
40#define CT82C710_IRQ          12
41
42#define CT82C710_DATA         ct82c710_iores.start
43#define CT82C710_STATUS       (ct82c710_iores.start + 1)
44
45static struct serio *ct82c710_port;
46static struct platform_device *ct82c710_device;
47static struct resource ct82c710_iores;
48
49/*
50 * Interrupt handler for the 82C710 mouse port. A character
51 * is waiting in the 82C710.
52 */
53
54static irqreturn_t ct82c710_interrupt(int cpl, void *dev_id)
55{
56	return serio_interrupt(ct82c710_port, inb(CT82C710_DATA), 0);
57}
58
59/*
60 * Wait for device to send output char and flush any input char.
61 */
62
63static int ct82c170_wait(void)
64{
65	int timeout = 60000;
66
67	while ((inb(CT82C710_STATUS) & (CT82C710_RX_FULL | CT82C710_TX_IDLE | CT82C710_DEV_IDLE))
68		       != (CT82C710_DEV_IDLE | CT82C710_TX_IDLE) && timeout) {
69
70		if (inb_p(CT82C710_STATUS) & CT82C710_RX_FULL) inb_p(CT82C710_DATA);
71
72		udelay(1);
73		timeout--;
74	}
75
76	return !timeout;
77}
78
79static void ct82c710_close(struct serio *serio)
80{
81	if (ct82c170_wait())
82		printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");
83
84	outb_p(inb_p(CT82C710_STATUS) & ~(CT82C710_ENABLE | CT82C710_INTS_ON), CT82C710_STATUS);
85
86	if (ct82c170_wait())
87		printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");
88
89	free_irq(CT82C710_IRQ, NULL);
90}
91
92static int ct82c710_open(struct serio *serio)
93{
94	unsigned char status;
95	int err;
96
97	err = request_irq(CT82C710_IRQ, ct82c710_interrupt, 0, "ct82c710", NULL);
98	if (err)
99		return err;
100
101	status = inb_p(CT82C710_STATUS);
102
103	status |= (CT82C710_ENABLE | CT82C710_RESET);
104	outb_p(status, CT82C710_STATUS);
105
106	status &= ~(CT82C710_RESET);
107	outb_p(status, CT82C710_STATUS);
108
109	status |= CT82C710_INTS_ON;
110	outb_p(status, CT82C710_STATUS);	/* Enable interrupts */
111
112	while (ct82c170_wait()) {
113		printk(KERN_ERR "ct82c710: Device busy in open()\n");
114		status &= ~(CT82C710_ENABLE | CT82C710_INTS_ON);
115		outb_p(status, CT82C710_STATUS);
116		free_irq(CT82C710_IRQ, NULL);
117		return -EBUSY;
118	}
119
120	return 0;
121}
122
123/*
124 * Write to the 82C710 mouse device.
125 */
126
127static int ct82c710_write(struct serio *port, unsigned char c)
128{
129	if (ct82c170_wait()) return -1;
130	outb_p(c, CT82C710_DATA);
131	return 0;
132}
133
134/*
135 * See if we can find a 82C710 device. Read mouse address.
136 */
137
138static int __init ct82c710_detect(void)
139{
140	outb_p(0x55, 0x2fa);				/* Any value except 9, ff or 36 */
141	outb_p(0xaa, 0x3fa);				/* Inverse of 55 */
142	outb_p(0x36, 0x3fa);				/* Address the chip */
143	outb_p(0xe4, 0x3fa);				/* 390/4; 390 = config address */
144	outb_p(0x1b, 0x2fa);				/* Inverse of e4 */
145	outb_p(0x0f, 0x390);				/* Write index */
146	if (inb_p(0x391) != 0xe4)			/* Config address found? */
147		return -ENODEV;				/* No: no 82C710 here */
148
149	outb_p(0x0d, 0x390);				/* Write index */
150	ct82c710_iores.start = inb_p(0x391) << 2;	/* Get mouse I/O address */
151	ct82c710_iores.end = ct82c710_iores.start + 1;
152	ct82c710_iores.flags = IORESOURCE_IO;
153	outb_p(0x0f, 0x390);
154	outb_p(0x0f, 0x391);				/* Close config mode */
155
156	return 0;
157}
158
159static int ct82c710_probe(struct platform_device *dev)
160{
161	ct82c710_port = kzalloc(sizeof(struct serio), GFP_KERNEL);
162	if (!ct82c710_port)
163		return -ENOMEM;
164
165	ct82c710_port->id.type = SERIO_8042;
166	ct82c710_port->dev.parent = &dev->dev;
167	ct82c710_port->open = ct82c710_open;
168	ct82c710_port->close = ct82c710_close;
169	ct82c710_port->write = ct82c710_write;
170	strscpy(ct82c710_port->name, "C&T 82c710 mouse port",
171		sizeof(ct82c710_port->name));
172	snprintf(ct82c710_port->phys, sizeof(ct82c710_port->phys),
173		 "isa%16llx/serio0", (unsigned long long)CT82C710_DATA);
174
175	serio_register_port(ct82c710_port);
176
177	printk(KERN_INFO "serio: C&T 82c710 mouse port at %#llx irq %d\n",
178		(unsigned long long)CT82C710_DATA, CT82C710_IRQ);
179
180	return 0;
181}
182
183static void ct82c710_remove(struct platform_device *dev)
184{
185	serio_unregister_port(ct82c710_port);
186}
187
188static struct platform_driver ct82c710_driver = {
189	.driver		= {
190		.name	= "ct82c710",
191	},
192	.probe		= ct82c710_probe,
193	.remove_new	= ct82c710_remove,
194};
195
196
197static int __init ct82c710_init(void)
198{
199	int error;
200
201	error = ct82c710_detect();
202	if (error)
203		return error;
204
205	error = platform_driver_register(&ct82c710_driver);
206	if (error)
207		return error;
208
209	ct82c710_device = platform_device_alloc("ct82c710", -1);
210	if (!ct82c710_device) {
211		error = -ENOMEM;
212		goto err_unregister_driver;
213	}
214
215	error = platform_device_add_resources(ct82c710_device, &ct82c710_iores, 1);
216	if (error)
217		goto err_free_device;
218
219	error = platform_device_add(ct82c710_device);
220	if (error)
221		goto err_free_device;
222
223	return 0;
224
225 err_free_device:
226	platform_device_put(ct82c710_device);
227 err_unregister_driver:
228	platform_driver_unregister(&ct82c710_driver);
229	return error;
230}
231
232static void __exit ct82c710_exit(void)
233{
234	platform_device_unregister(ct82c710_device);
235	platform_driver_unregister(&ct82c710_driver);
236}
237
238module_init(ct82c710_init);
239module_exit(ct82c710_exit);
240