xref: /openbmc/linux/drivers/input/serio/ct82c710.c (revision 8795a739)
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 /*
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/module.h>
15 #include <linux/ioport.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/serio.h>
19 #include <linux/errno.h>
20 #include <linux/err.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 
24 #include <asm/io.h>
25 
26 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
27 MODULE_DESCRIPTION("82C710 C&T mouse port chip driver");
28 MODULE_LICENSE("GPL");
29 
30 /*
31  * ct82c710 interface
32  */
33 
34 #define CT82C710_DEV_IDLE     0x01		/* Device Idle */
35 #define CT82C710_RX_FULL      0x02		/* Device Char received */
36 #define CT82C710_TX_IDLE      0x04		/* Device XMIT Idle */
37 #define CT82C710_RESET        0x08		/* Device Reset */
38 #define CT82C710_INTS_ON      0x10		/* Device Interrupt On */
39 #define CT82C710_ERROR_FLAG   0x20		/* Device Error */
40 #define CT82C710_CLEAR        0x40		/* Device Clear */
41 #define CT82C710_ENABLE       0x80		/* Device Enable */
42 
43 #define CT82C710_IRQ          12
44 
45 #define CT82C710_DATA         ct82c710_iores.start
46 #define CT82C710_STATUS       (ct82c710_iores.start + 1)
47 
48 static struct serio *ct82c710_port;
49 static struct platform_device *ct82c710_device;
50 static struct resource ct82c710_iores;
51 
52 /*
53  * Interrupt handler for the 82C710 mouse port. A character
54  * is waiting in the 82C710.
55  */
56 
57 static irqreturn_t ct82c710_interrupt(int cpl, void *dev_id)
58 {
59 	return serio_interrupt(ct82c710_port, inb(CT82C710_DATA), 0);
60 }
61 
62 /*
63  * Wait for device to send output char and flush any input char.
64  */
65 
66 static int ct82c170_wait(void)
67 {
68 	int timeout = 60000;
69 
70 	while ((inb(CT82C710_STATUS) & (CT82C710_RX_FULL | CT82C710_TX_IDLE | CT82C710_DEV_IDLE))
71 		       != (CT82C710_DEV_IDLE | CT82C710_TX_IDLE) && timeout) {
72 
73 		if (inb_p(CT82C710_STATUS) & CT82C710_RX_FULL) inb_p(CT82C710_DATA);
74 
75 		udelay(1);
76 		timeout--;
77 	}
78 
79 	return !timeout;
80 }
81 
82 static void ct82c710_close(struct serio *serio)
83 {
84 	if (ct82c170_wait())
85 		printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");
86 
87 	outb_p(inb_p(CT82C710_STATUS) & ~(CT82C710_ENABLE | CT82C710_INTS_ON), CT82C710_STATUS);
88 
89 	if (ct82c170_wait())
90 		printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");
91 
92 	free_irq(CT82C710_IRQ, NULL);
93 }
94 
95 static int ct82c710_open(struct serio *serio)
96 {
97 	unsigned char status;
98 	int err;
99 
100 	err = request_irq(CT82C710_IRQ, ct82c710_interrupt, 0, "ct82c710", NULL);
101 	if (err)
102 		return err;
103 
104 	status = inb_p(CT82C710_STATUS);
105 
106 	status |= (CT82C710_ENABLE | CT82C710_RESET);
107 	outb_p(status, CT82C710_STATUS);
108 
109 	status &= ~(CT82C710_RESET);
110 	outb_p(status, CT82C710_STATUS);
111 
112 	status |= CT82C710_INTS_ON;
113 	outb_p(status, CT82C710_STATUS);	/* Enable interrupts */
114 
115 	while (ct82c170_wait()) {
116 		printk(KERN_ERR "ct82c710: Device busy in open()\n");
117 		status &= ~(CT82C710_ENABLE | CT82C710_INTS_ON);
118 		outb_p(status, CT82C710_STATUS);
119 		free_irq(CT82C710_IRQ, NULL);
120 		return -EBUSY;
121 	}
122 
123 	return 0;
124 }
125 
126 /*
127  * Write to the 82C710 mouse device.
128  */
129 
130 static int ct82c710_write(struct serio *port, unsigned char c)
131 {
132 	if (ct82c170_wait()) return -1;
133 	outb_p(c, CT82C710_DATA);
134 	return 0;
135 }
136 
137 /*
138  * See if we can find a 82C710 device. Read mouse address.
139  */
140 
141 static int __init ct82c710_detect(void)
142 {
143 	outb_p(0x55, 0x2fa);				/* Any value except 9, ff or 36 */
144 	outb_p(0xaa, 0x3fa);				/* Inverse of 55 */
145 	outb_p(0x36, 0x3fa);				/* Address the chip */
146 	outb_p(0xe4, 0x3fa);				/* 390/4; 390 = config address */
147 	outb_p(0x1b, 0x2fa);				/* Inverse of e4 */
148 	outb_p(0x0f, 0x390);				/* Write index */
149 	if (inb_p(0x391) != 0xe4)			/* Config address found? */
150 		return -ENODEV;				/* No: no 82C710 here */
151 
152 	outb_p(0x0d, 0x390);				/* Write index */
153 	ct82c710_iores.start = inb_p(0x391) << 2;	/* Get mouse I/O address */
154 	ct82c710_iores.end = ct82c710_iores.start + 1;
155 	ct82c710_iores.flags = IORESOURCE_IO;
156 	outb_p(0x0f, 0x390);
157 	outb_p(0x0f, 0x391);				/* Close config mode */
158 
159 	return 0;
160 }
161 
162 static int ct82c710_probe(struct platform_device *dev)
163 {
164 	ct82c710_port = kzalloc(sizeof(struct serio), GFP_KERNEL);
165 	if (!ct82c710_port)
166 		return -ENOMEM;
167 
168 	ct82c710_port->id.type = SERIO_8042;
169 	ct82c710_port->dev.parent = &dev->dev;
170 	ct82c710_port->open = ct82c710_open;
171 	ct82c710_port->close = ct82c710_close;
172 	ct82c710_port->write = ct82c710_write;
173 	strlcpy(ct82c710_port->name, "C&T 82c710 mouse port",
174 		sizeof(ct82c710_port->name));
175 	snprintf(ct82c710_port->phys, sizeof(ct82c710_port->phys),
176 		 "isa%16llx/serio0", (unsigned long long)CT82C710_DATA);
177 
178 	serio_register_port(ct82c710_port);
179 
180 	printk(KERN_INFO "serio: C&T 82c710 mouse port at %#llx irq %d\n",
181 		(unsigned long long)CT82C710_DATA, CT82C710_IRQ);
182 
183 	return 0;
184 }
185 
186 static int ct82c710_remove(struct platform_device *dev)
187 {
188 	serio_unregister_port(ct82c710_port);
189 
190 	return 0;
191 }
192 
193 static struct platform_driver ct82c710_driver = {
194 	.driver		= {
195 		.name	= "ct82c710",
196 	},
197 	.probe		= ct82c710_probe,
198 	.remove		= ct82c710_remove,
199 };
200 
201 
202 static int __init ct82c710_init(void)
203 {
204 	int error;
205 
206 	error = ct82c710_detect();
207 	if (error)
208 		return error;
209 
210 	error = platform_driver_register(&ct82c710_driver);
211 	if (error)
212 		return error;
213 
214 	ct82c710_device = platform_device_alloc("ct82c710", -1);
215 	if (!ct82c710_device) {
216 		error = -ENOMEM;
217 		goto err_unregister_driver;
218 	}
219 
220 	error = platform_device_add_resources(ct82c710_device, &ct82c710_iores, 1);
221 	if (error)
222 		goto err_free_device;
223 
224 	error = platform_device_add(ct82c710_device);
225 	if (error)
226 		goto err_free_device;
227 
228 	return 0;
229 
230  err_free_device:
231 	platform_device_put(ct82c710_device);
232  err_unregister_driver:
233 	platform_driver_unregister(&ct82c710_driver);
234 	return error;
235 }
236 
237 static void __exit ct82c710_exit(void)
238 {
239 	platform_device_unregister(ct82c710_device);
240 	platform_driver_unregister(&ct82c710_driver);
241 }
242 
243 module_init(ct82c710_init);
244 module_exit(ct82c710_exit);
245