xref: /openbmc/linux/drivers/input/serio/q40kbd.c (revision 7f6964c5)
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 /*
14  */
15 
16 #include <linux/module.h>
17 #include <linux/serio.h>
18 #include <linux/interrupt.h>
19 #include <linux/err.h>
20 #include <linux/bitops.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 
24 #include <asm/io.h>
25 #include <linux/uaccess.h>
26 #include <asm/q40_master.h>
27 #include <asm/irq.h>
28 #include <asm/q40ints.h>
29 
30 #define DRV_NAME	"q40kbd"
31 
32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
33 MODULE_DESCRIPTION("Q40 PS/2 keyboard controller driver");
34 MODULE_LICENSE("GPL");
35 MODULE_ALIAS("platform:" DRV_NAME);
36 
37 struct q40kbd {
38 	struct serio *port;
39 	spinlock_t lock;
40 };
41 
42 static irqreturn_t q40kbd_interrupt(int irq, void *dev_id)
43 {
44 	struct q40kbd *q40kbd = dev_id;
45 	unsigned long flags;
46 
47 	spin_lock_irqsave(&q40kbd->lock, flags);
48 
49 	if (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG))
50 		serio_interrupt(q40kbd->port, master_inb(KEYCODE_REG), 0);
51 
52 	master_outb(-1, KEYBOARD_UNLOCK_REG);
53 
54 	spin_unlock_irqrestore(&q40kbd->lock, flags);
55 
56 	return IRQ_HANDLED;
57 }
58 
59 /*
60  * q40kbd_flush() flushes all data that may be in the keyboard buffers
61  */
62 
63 static void q40kbd_flush(struct q40kbd *q40kbd)
64 {
65 	int maxread = 100;
66 	unsigned long flags;
67 
68 	spin_lock_irqsave(&q40kbd->lock, flags);
69 
70 	while (maxread-- && (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG)))
71 		master_inb(KEYCODE_REG);
72 
73 	spin_unlock_irqrestore(&q40kbd->lock, flags);
74 }
75 
76 static void q40kbd_stop(void)
77 {
78 	master_outb(0, KEY_IRQ_ENABLE_REG);
79 	master_outb(-1, KEYBOARD_UNLOCK_REG);
80 }
81 
82 /*
83  * q40kbd_open() is called when a port is open by the higher layer.
84  * It allocates the interrupt and enables in in the chip.
85  */
86 
87 static int q40kbd_open(struct serio *port)
88 {
89 	struct q40kbd *q40kbd = port->port_data;
90 
91 	q40kbd_flush(q40kbd);
92 
93 	/* off we go */
94 	master_outb(-1, KEYBOARD_UNLOCK_REG);
95 	master_outb(1, KEY_IRQ_ENABLE_REG);
96 
97 	return 0;
98 }
99 
100 static void q40kbd_close(struct serio *port)
101 {
102 	struct q40kbd *q40kbd = port->port_data;
103 
104 	q40kbd_stop();
105 	q40kbd_flush(q40kbd);
106 }
107 
108 static int q40kbd_probe(struct platform_device *pdev)
109 {
110 	struct q40kbd *q40kbd;
111 	struct serio *port;
112 	int error;
113 
114 	q40kbd = kzalloc(sizeof(struct q40kbd), GFP_KERNEL);
115 	port = kzalloc(sizeof(struct serio), GFP_KERNEL);
116 	if (!q40kbd || !port) {
117 		error = -ENOMEM;
118 		goto err_free_mem;
119 	}
120 
121 	q40kbd->port = port;
122 	spin_lock_init(&q40kbd->lock);
123 
124 	port->id.type = SERIO_8042;
125 	port->open = q40kbd_open;
126 	port->close = q40kbd_close;
127 	port->port_data = q40kbd;
128 	port->dev.parent = &pdev->dev;
129 	strlcpy(port->name, "Q40 Kbd Port", sizeof(port->name));
130 	strlcpy(port->phys, "Q40", sizeof(port->phys));
131 
132 	q40kbd_stop();
133 
134 	error = request_irq(Q40_IRQ_KEYBOARD, q40kbd_interrupt, 0,
135 			    DRV_NAME, q40kbd);
136 	if (error) {
137 		dev_err(&pdev->dev, "Can't get irq %d.\n", Q40_IRQ_KEYBOARD);
138 		goto err_free_mem;
139 	}
140 
141 	serio_register_port(q40kbd->port);
142 
143 	platform_set_drvdata(pdev, q40kbd);
144 	printk(KERN_INFO "serio: Q40 kbd registered\n");
145 
146 	return 0;
147 
148 err_free_mem:
149 	kfree(port);
150 	kfree(q40kbd);
151 	return error;
152 }
153 
154 static int q40kbd_remove(struct platform_device *pdev)
155 {
156 	struct q40kbd *q40kbd = platform_get_drvdata(pdev);
157 
158 	/*
159 	 * q40kbd_close() will be called as part of unregistering
160 	 * and will ensure that IRQ is turned off, so it is safe
161 	 * to unregister port first and free IRQ later.
162 	 */
163 	serio_unregister_port(q40kbd->port);
164 	free_irq(Q40_IRQ_KEYBOARD, q40kbd);
165 	kfree(q40kbd);
166 
167 	return 0;
168 }
169 
170 static struct platform_driver q40kbd_driver = {
171 	.driver		= {
172 		.name	= "q40kbd",
173 	},
174 	.remove		= q40kbd_remove,
175 };
176 
177 module_platform_driver_probe(q40kbd_driver, q40kbd_probe);
178