xref: /linux/drivers/input/serio/q40kbd.c (revision 3e51108c72e8adbcf3180ed40527a2a9d2d0123b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) 2000-2001 Vojtech Pavlik
4  *
5  *  Based on the work of:
6  *	Richard Zidlicky <Richard.Zidlicky@stud.informatik.uni-erlangen.de>
7  */
8 
9 /*
10  * Q40 PS/2 keyboard controller driver for Linux/m68k
11  */
12 
13 #include <linux/module.h>
14 #include <linux/serio.h>
15 #include <linux/interrupt.h>
16 #include <linux/err.h>
17 #include <linux/bitops.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 
21 #include <asm/io.h>
22 #include <linux/uaccess.h>
23 #include <asm/q40_master.h>
24 #include <asm/irq.h>
25 #include <asm/q40ints.h>
26 
27 #define DRV_NAME	"q40kbd"
28 
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30 MODULE_DESCRIPTION("Q40 PS/2 keyboard controller driver");
31 MODULE_LICENSE("GPL");
32 MODULE_ALIAS("platform:" DRV_NAME);
33 
34 struct q40kbd {
35 	struct serio *port;
36 	spinlock_t lock;
37 };
38 
q40kbd_interrupt(int irq,void * dev_id)39 static irqreturn_t q40kbd_interrupt(int irq, void *dev_id)
40 {
41 	struct q40kbd *q40kbd = dev_id;
42 
43 	guard(spinlock_irqsave)(&q40kbd->lock);
44 
45 	if (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG))
46 		serio_interrupt(q40kbd->port, master_inb(KEYCODE_REG), 0);
47 
48 	master_outb(-1, KEYBOARD_UNLOCK_REG);
49 
50 	return IRQ_HANDLED;
51 }
52 
53 /*
54  * q40kbd_flush() flushes all data that may be in the keyboard buffers
55  */
56 
q40kbd_flush(struct q40kbd * q40kbd)57 static void q40kbd_flush(struct q40kbd *q40kbd)
58 {
59 	int maxread = 100;
60 
61 	guard(spinlock_irqsave)(&q40kbd->lock);
62 
63 	while (maxread-- && (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG)))
64 		master_inb(KEYCODE_REG);
65 }
66 
q40kbd_stop(void)67 static void q40kbd_stop(void)
68 {
69 	master_outb(0, KEY_IRQ_ENABLE_REG);
70 	master_outb(-1, KEYBOARD_UNLOCK_REG);
71 }
72 
73 /*
74  * q40kbd_open() is called when a port is open by the higher layer.
75  * It allocates the interrupt and enables in in the chip.
76  */
77 
q40kbd_open(struct serio * port)78 static int q40kbd_open(struct serio *port)
79 {
80 	struct q40kbd *q40kbd = port->port_data;
81 
82 	q40kbd_flush(q40kbd);
83 
84 	/* off we go */
85 	master_outb(-1, KEYBOARD_UNLOCK_REG);
86 	master_outb(1, KEY_IRQ_ENABLE_REG);
87 
88 	return 0;
89 }
90 
q40kbd_close(struct serio * port)91 static void q40kbd_close(struct serio *port)
92 {
93 	struct q40kbd *q40kbd = port->port_data;
94 
95 	q40kbd_stop();
96 	q40kbd_flush(q40kbd);
97 }
98 
q40kbd_probe(struct platform_device * pdev)99 static int q40kbd_probe(struct platform_device *pdev)
100 {
101 	struct q40kbd *q40kbd;
102 	struct serio *port;
103 	int error;
104 
105 	q40kbd = kzalloc(sizeof(*q40kbd), GFP_KERNEL);
106 	port = kzalloc(sizeof(*port), GFP_KERNEL);
107 	if (!q40kbd || !port) {
108 		error = -ENOMEM;
109 		goto err_free_mem;
110 	}
111 
112 	q40kbd->port = port;
113 	spin_lock_init(&q40kbd->lock);
114 
115 	port->id.type = SERIO_8042;
116 	port->open = q40kbd_open;
117 	port->close = q40kbd_close;
118 	port->port_data = q40kbd;
119 	port->dev.parent = &pdev->dev;
120 	strscpy(port->name, "Q40 Kbd Port", sizeof(port->name));
121 	strscpy(port->phys, "Q40", sizeof(port->phys));
122 
123 	q40kbd_stop();
124 
125 	error = request_irq(Q40_IRQ_KEYBOARD, q40kbd_interrupt, 0,
126 			    DRV_NAME, q40kbd);
127 	if (error) {
128 		dev_err(&pdev->dev, "Can't get irq %d.\n", Q40_IRQ_KEYBOARD);
129 		goto err_free_mem;
130 	}
131 
132 	serio_register_port(q40kbd->port);
133 
134 	platform_set_drvdata(pdev, q40kbd);
135 	printk(KERN_INFO "serio: Q40 kbd registered\n");
136 
137 	return 0;
138 
139 err_free_mem:
140 	kfree(port);
141 	kfree(q40kbd);
142 	return error;
143 }
144 
q40kbd_remove(struct platform_device * pdev)145 static void q40kbd_remove(struct platform_device *pdev)
146 {
147 	struct q40kbd *q40kbd = platform_get_drvdata(pdev);
148 
149 	/*
150 	 * q40kbd_close() will be called as part of unregistering
151 	 * and will ensure that IRQ is turned off, so it is safe
152 	 * to unregister port first and free IRQ later.
153 	 */
154 	serio_unregister_port(q40kbd->port);
155 	free_irq(Q40_IRQ_KEYBOARD, q40kbd);
156 	kfree(q40kbd);
157 }
158 
159 static struct platform_driver q40kbd_driver = {
160 	.driver		= {
161 		.name	= "q40kbd",
162 	},
163 	.remove		= q40kbd_remove,
164 };
165 
166 module_platform_driver_probe(q40kbd_driver, q40kbd_probe);
167