xref: /openbmc/linux/drivers/input/serio/q40kbd.c (revision 7effbd18)
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 
39 static irqreturn_t q40kbd_interrupt(int irq, void *dev_id)
40 {
41 	struct q40kbd *q40kbd = dev_id;
42 	unsigned long flags;
43 
44 	spin_lock_irqsave(&q40kbd->lock, flags);
45 
46 	if (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG))
47 		serio_interrupt(q40kbd->port, master_inb(KEYCODE_REG), 0);
48 
49 	master_outb(-1, KEYBOARD_UNLOCK_REG);
50 
51 	spin_unlock_irqrestore(&q40kbd->lock, flags);
52 
53 	return IRQ_HANDLED;
54 }
55 
56 /*
57  * q40kbd_flush() flushes all data that may be in the keyboard buffers
58  */
59 
60 static void q40kbd_flush(struct q40kbd *q40kbd)
61 {
62 	int maxread = 100;
63 	unsigned long flags;
64 
65 	spin_lock_irqsave(&q40kbd->lock, flags);
66 
67 	while (maxread-- && (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG)))
68 		master_inb(KEYCODE_REG);
69 
70 	spin_unlock_irqrestore(&q40kbd->lock, flags);
71 }
72 
73 static void q40kbd_stop(void)
74 {
75 	master_outb(0, KEY_IRQ_ENABLE_REG);
76 	master_outb(-1, KEYBOARD_UNLOCK_REG);
77 }
78 
79 /*
80  * q40kbd_open() is called when a port is open by the higher layer.
81  * It allocates the interrupt and enables in in the chip.
82  */
83 
84 static int q40kbd_open(struct serio *port)
85 {
86 	struct q40kbd *q40kbd = port->port_data;
87 
88 	q40kbd_flush(q40kbd);
89 
90 	/* off we go */
91 	master_outb(-1, KEYBOARD_UNLOCK_REG);
92 	master_outb(1, KEY_IRQ_ENABLE_REG);
93 
94 	return 0;
95 }
96 
97 static void q40kbd_close(struct serio *port)
98 {
99 	struct q40kbd *q40kbd = port->port_data;
100 
101 	q40kbd_stop();
102 	q40kbd_flush(q40kbd);
103 }
104 
105 static int q40kbd_probe(struct platform_device *pdev)
106 {
107 	struct q40kbd *q40kbd;
108 	struct serio *port;
109 	int error;
110 
111 	q40kbd = kzalloc(sizeof(struct q40kbd), GFP_KERNEL);
112 	port = kzalloc(sizeof(struct serio), GFP_KERNEL);
113 	if (!q40kbd || !port) {
114 		error = -ENOMEM;
115 		goto err_free_mem;
116 	}
117 
118 	q40kbd->port = port;
119 	spin_lock_init(&q40kbd->lock);
120 
121 	port->id.type = SERIO_8042;
122 	port->open = q40kbd_open;
123 	port->close = q40kbd_close;
124 	port->port_data = q40kbd;
125 	port->dev.parent = &pdev->dev;
126 	strscpy(port->name, "Q40 Kbd Port", sizeof(port->name));
127 	strscpy(port->phys, "Q40", sizeof(port->phys));
128 
129 	q40kbd_stop();
130 
131 	error = request_irq(Q40_IRQ_KEYBOARD, q40kbd_interrupt, 0,
132 			    DRV_NAME, q40kbd);
133 	if (error) {
134 		dev_err(&pdev->dev, "Can't get irq %d.\n", Q40_IRQ_KEYBOARD);
135 		goto err_free_mem;
136 	}
137 
138 	serio_register_port(q40kbd->port);
139 
140 	platform_set_drvdata(pdev, q40kbd);
141 	printk(KERN_INFO "serio: Q40 kbd registered\n");
142 
143 	return 0;
144 
145 err_free_mem:
146 	kfree(port);
147 	kfree(q40kbd);
148 	return error;
149 }
150 
151 static int q40kbd_remove(struct platform_device *pdev)
152 {
153 	struct q40kbd *q40kbd = platform_get_drvdata(pdev);
154 
155 	/*
156 	 * q40kbd_close() will be called as part of unregistering
157 	 * and will ensure that IRQ is turned off, so it is safe
158 	 * to unregister port first and free IRQ later.
159 	 */
160 	serio_unregister_port(q40kbd->port);
161 	free_irq(Q40_IRQ_KEYBOARD, q40kbd);
162 	kfree(q40kbd);
163 
164 	return 0;
165 }
166 
167 static struct platform_driver q40kbd_driver = {
168 	.driver		= {
169 		.name	= "q40kbd",
170 	},
171 	.remove		= q40kbd_remove,
172 };
173 
174 module_platform_driver_probe(q40kbd_driver, q40kbd_probe);
175