1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/input.h>
3 #include <linux/module.h>
4 #include <linux/init.h>
5 #include <linux/interrupt.h>
6 #include <asm/io.h>
7 #include <asm/delay.h>
8 #include <asm/adc.h>
9 #include <mach/hp6xx.h>
10 
11 #define MODNAME "hp680_ts_input"
12 
13 #define HP680_TS_ABS_X_MIN	40
14 #define HP680_TS_ABS_X_MAX	950
15 #define HP680_TS_ABS_Y_MIN	80
16 #define HP680_TS_ABS_Y_MAX	910
17 
18 #define	PHDR	0xa400012e
19 #define SCPDR	0xa4000136
20 
21 static void do_softint(struct work_struct *work);
22 
23 static struct input_dev *hp680_ts_dev;
24 static DECLARE_DELAYED_WORK(work, do_softint);
25 
26 static void do_softint(struct work_struct *work)
27 {
28 	int absx = 0, absy = 0;
29 	u8 scpdr;
30 	int touched = 0;
31 
32 	if (__raw_readb(PHDR) & PHDR_TS_PEN_DOWN) {
33 		scpdr = __raw_readb(SCPDR);
34 		scpdr |= SCPDR_TS_SCAN_ENABLE;
35 		scpdr &= ~SCPDR_TS_SCAN_Y;
36 		__raw_writeb(scpdr, SCPDR);
37 		udelay(30);
38 
39 		absy = adc_single(ADC_CHANNEL_TS_Y);
40 
41 		scpdr = __raw_readb(SCPDR);
42 		scpdr |= SCPDR_TS_SCAN_Y;
43 		scpdr &= ~SCPDR_TS_SCAN_X;
44 		__raw_writeb(scpdr, SCPDR);
45 		udelay(30);
46 
47 		absx = adc_single(ADC_CHANNEL_TS_X);
48 
49 		scpdr = __raw_readb(SCPDR);
50 		scpdr |= SCPDR_TS_SCAN_X;
51 		scpdr &= ~SCPDR_TS_SCAN_ENABLE;
52 		__raw_writeb(scpdr, SCPDR);
53 		udelay(100);
54 		touched = __raw_readb(PHDR) & PHDR_TS_PEN_DOWN;
55 	}
56 
57 	if (touched) {
58 		input_report_key(hp680_ts_dev, BTN_TOUCH, 1);
59 		input_report_abs(hp680_ts_dev, ABS_X, absx);
60 		input_report_abs(hp680_ts_dev, ABS_Y, absy);
61 	} else {
62 		input_report_key(hp680_ts_dev, BTN_TOUCH, 0);
63 	}
64 
65 	input_sync(hp680_ts_dev);
66 	enable_irq(HP680_TS_IRQ);
67 }
68 
69 static irqreturn_t hp680_ts_interrupt(int irq, void *dev)
70 {
71 	disable_irq_nosync(irq);
72 	schedule_delayed_work(&work, HZ / 20);
73 
74 	return IRQ_HANDLED;
75 }
76 
77 static int __init hp680_ts_init(void)
78 {
79 	int err;
80 
81 	hp680_ts_dev = input_allocate_device();
82 	if (!hp680_ts_dev)
83 		return -ENOMEM;
84 
85 	hp680_ts_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
86 	hp680_ts_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
87 
88 	input_set_abs_params(hp680_ts_dev, ABS_X,
89 		HP680_TS_ABS_X_MIN, HP680_TS_ABS_X_MAX, 0, 0);
90 	input_set_abs_params(hp680_ts_dev, ABS_Y,
91 		HP680_TS_ABS_Y_MIN, HP680_TS_ABS_Y_MAX, 0, 0);
92 
93 	hp680_ts_dev->name = "HP Jornada touchscreen";
94 	hp680_ts_dev->phys = "hp680_ts/input0";
95 
96 	if (request_irq(HP680_TS_IRQ, hp680_ts_interrupt,
97 			0, MODNAME, NULL) < 0) {
98 		printk(KERN_ERR "hp680_touchscreen.c: Can't allocate irq %d\n",
99 		       HP680_TS_IRQ);
100 		err = -EBUSY;
101 		goto fail1;
102 	}
103 
104 	err = input_register_device(hp680_ts_dev);
105 	if (err)
106 		goto fail2;
107 
108 	return 0;
109 
110  fail2:	free_irq(HP680_TS_IRQ, NULL);
111 	cancel_delayed_work_sync(&work);
112  fail1:	input_free_device(hp680_ts_dev);
113 	return err;
114 }
115 
116 static void __exit hp680_ts_exit(void)
117 {
118 	free_irq(HP680_TS_IRQ, NULL);
119 	cancel_delayed_work_sync(&work);
120 	input_unregister_device(hp680_ts_dev);
121 }
122 
123 module_init(hp680_ts_init);
124 module_exit(hp680_ts_exit);
125 
126 MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua");
127 MODULE_DESCRIPTION("HP Jornada 680 touchscreen driver");
128 MODULE_LICENSE("GPL");
129