1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ICS MK712 touchscreen controller driver
4  *
5  * Copyright (c) 1999-2002 Transmeta Corporation
6  * Copyright (c) 2005 Rick Koch <n1gp@hotmail.com>
7  * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
8  */
9 
10 
11 /*
12  * This driver supports the ICS MicroClock MK712 TouchScreen controller,
13  * found in Gateway AOL Connected Touchpad computers.
14  *
15  * Documentation for ICS MK712 can be found at:
16  *	https://www.idt.com/general-parts/mk712-touch-screen-controller
17  */
18 
19 /*
20  * 1999-12-18: original version, Daniel Quinlan
21  * 1999-12-19: added anti-jitter code, report pen-up events, fixed mk712_poll
22  *             to use queue_empty, Nathan Laredo
23  * 1999-12-20: improved random point rejection, Nathan Laredo
24  * 2000-01-05: checked in new anti-jitter code, changed mouse protocol, fixed
25  *             queue code, added module options, other fixes, Daniel Quinlan
26  * 2002-03-15: Clean up for kernel merge <alan@redhat.com>
27  *             Fixed multi open race, fixed memory checks, fixed resource
28  *             allocation, fixed close/powerdown bug, switched to new init
29  * 2005-01-18: Ported to 2.6 from 2.4.28, Rick Koch
30  * 2005-02-05: Rewritten for the input layer, Vojtech Pavlik
31  *
32  */
33 
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/init.h>
37 #include <linux/errno.h>
38 #include <linux/delay.h>
39 #include <linux/ioport.h>
40 #include <linux/interrupt.h>
41 #include <linux/input.h>
42 #include <asm/io.h>
43 
44 MODULE_AUTHOR("Daniel Quinlan <quinlan@pathname.com>, Vojtech Pavlik <vojtech@suse.cz>");
45 MODULE_DESCRIPTION("ICS MicroClock MK712 TouchScreen driver");
46 MODULE_LICENSE("GPL");
47 
48 static unsigned int mk712_io = 0x260;	/* Also 0x200, 0x208, 0x300 */
49 module_param_hw_named(io, mk712_io, uint, ioport, 0);
50 MODULE_PARM_DESC(io, "I/O base address of MK712 touchscreen controller");
51 
52 static unsigned int mk712_irq = 10;	/* Also 12, 14, 15 */
53 module_param_hw_named(irq, mk712_irq, uint, irq, 0);
54 MODULE_PARM_DESC(irq, "IRQ of MK712 touchscreen controller");
55 
56 /* eight 8-bit registers */
57 #define MK712_STATUS		0
58 #define MK712_X			2
59 #define MK712_Y			4
60 #define MK712_CONTROL		6
61 #define MK712_RATE		7
62 
63 /* status */
64 #define	MK712_STATUS_TOUCH			0x10
65 #define	MK712_CONVERSION_COMPLETE		0x80
66 
67 /* control */
68 #define MK712_ENABLE_INT			0x01
69 #define MK712_INT_ON_CONVERSION_COMPLETE	0x02
70 #define MK712_INT_ON_CHANGE_IN_TOUCH_STATUS	0x04
71 #define MK712_ENABLE_PERIODIC_CONVERSIONS	0x10
72 #define MK712_READ_ONE_POINT			0x20
73 #define MK712_POWERUP				0x40
74 
75 static struct input_dev *mk712_dev;
76 static DEFINE_SPINLOCK(mk712_lock);
77 
78 static irqreturn_t mk712_interrupt(int irq, void *dev_id)
79 {
80 	unsigned char status;
81 	static int debounce = 1;
82 	static unsigned short last_x;
83 	static unsigned short last_y;
84 
85 	spin_lock(&mk712_lock);
86 
87 	status = inb(mk712_io + MK712_STATUS);
88 
89 	if (~status & MK712_CONVERSION_COMPLETE) {
90 		debounce = 1;
91 		goto end;
92 	}
93 
94 	if (~status & MK712_STATUS_TOUCH) {
95 		debounce = 1;
96 		input_report_key(mk712_dev, BTN_TOUCH, 0);
97 		goto end;
98 	}
99 
100 	if (debounce) {
101 		debounce = 0;
102 		goto end;
103 	}
104 
105 	input_report_key(mk712_dev, BTN_TOUCH, 1);
106 	input_report_abs(mk712_dev, ABS_X, last_x);
107 	input_report_abs(mk712_dev, ABS_Y, last_y);
108 
109  end:
110 	last_x = inw(mk712_io + MK712_X) & 0x0fff;
111 	last_y = inw(mk712_io + MK712_Y) & 0x0fff;
112 	input_sync(mk712_dev);
113 	spin_unlock(&mk712_lock);
114 	return IRQ_HANDLED;
115 }
116 
117 static int mk712_open(struct input_dev *dev)
118 {
119 	unsigned long flags;
120 
121 	spin_lock_irqsave(&mk712_lock, flags);
122 
123 	outb(0, mk712_io + MK712_CONTROL); /* Reset */
124 
125 	outb(MK712_ENABLE_INT | MK712_INT_ON_CONVERSION_COMPLETE |
126 		MK712_INT_ON_CHANGE_IN_TOUCH_STATUS |
127 		MK712_ENABLE_PERIODIC_CONVERSIONS |
128 		MK712_POWERUP, mk712_io + MK712_CONTROL);
129 
130 	outb(10, mk712_io + MK712_RATE); /* 187 points per second */
131 
132 	spin_unlock_irqrestore(&mk712_lock, flags);
133 
134 	return 0;
135 }
136 
137 static void mk712_close(struct input_dev *dev)
138 {
139 	unsigned long flags;
140 
141 	spin_lock_irqsave(&mk712_lock, flags);
142 
143 	outb(0, mk712_io + MK712_CONTROL);
144 
145 	spin_unlock_irqrestore(&mk712_lock, flags);
146 }
147 
148 static int __init mk712_init(void)
149 {
150 	int err;
151 
152 	if (!request_region(mk712_io, 8, "mk712")) {
153 		printk(KERN_WARNING "mk712: unable to get IO region\n");
154 		return -ENODEV;
155 	}
156 
157 	outb(0, mk712_io + MK712_CONTROL);
158 
159 	if ((inw(mk712_io + MK712_X) & 0xf000) ||	/* Sanity check */
160 	    (inw(mk712_io + MK712_Y) & 0xf000) ||
161 	    (inw(mk712_io + MK712_STATUS) & 0xf333)) {
162 		printk(KERN_WARNING "mk712: device not present\n");
163 		err = -ENODEV;
164 		goto fail1;
165 	}
166 
167 	mk712_dev = input_allocate_device();
168 	if (!mk712_dev) {
169 		printk(KERN_ERR "mk712: not enough memory\n");
170 		err = -ENOMEM;
171 		goto fail1;
172 	}
173 
174 	mk712_dev->name = "ICS MicroClock MK712 TouchScreen";
175 	mk712_dev->phys = "isa0260/input0";
176 	mk712_dev->id.bustype = BUS_ISA;
177 	mk712_dev->id.vendor  = 0x0005;
178 	mk712_dev->id.product = 0x0001;
179 	mk712_dev->id.version = 0x0100;
180 
181 	mk712_dev->open    = mk712_open;
182 	mk712_dev->close   = mk712_close;
183 
184 	mk712_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
185 	mk712_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
186 	input_set_abs_params(mk712_dev, ABS_X, 0, 0xfff, 88, 0);
187 	input_set_abs_params(mk712_dev, ABS_Y, 0, 0xfff, 88, 0);
188 
189 	if (request_irq(mk712_irq, mk712_interrupt, 0, "mk712", mk712_dev)) {
190 		printk(KERN_WARNING "mk712: unable to get IRQ\n");
191 		err = -EBUSY;
192 		goto fail1;
193 	}
194 
195 	err = input_register_device(mk712_dev);
196 	if (err)
197 		goto fail2;
198 
199 	return 0;
200 
201  fail2:	free_irq(mk712_irq, mk712_dev);
202  fail1:	input_free_device(mk712_dev);
203 	release_region(mk712_io, 8);
204 	return err;
205 }
206 
207 static void __exit mk712_exit(void)
208 {
209 	input_unregister_device(mk712_dev);
210 	free_irq(mk712_irq, mk712_dev);
211 	release_region(mk712_io, 8);
212 }
213 
214 module_init(mk712_init);
215 module_exit(mk712_exit);
216