jornada720_ts.c revision 3638dd2b45ceac2e9526f0ee83b0923db3546979 
1/*
2 * drivers/input/touchscreen/jornada720_ts.c
3 *
4 * Copyright (C) 2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
5 *
6 *  Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
7 *  based on HP Jornada 56x touchscreen driver by Alex Lange <chicken@handhelds.org>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * HP Jornada 710/720/729 Touchscreen Driver
14 */
15
16#include <linux/platform_device.h>
17#include <linux/init.h>
18#include <linux/input.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22
23#include <mach/hardware.h>
24#include <mach/jornada720.h>
25#include <mach/irqs.h>
26
27MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
28MODULE_DESCRIPTION("HP Jornada 710/720/728 touchscreen driver");
29MODULE_LICENSE("GPL v2");
30
31struct jornada_ts {
32	struct input_dev *dev;
33	int x_data[4];		/* X sample values */
34	int y_data[4];		/* Y sample values */
35};
36
37static void jornada720_ts_collect_data(struct jornada_ts *jornada_ts)
38{
39
40    /* 3 low word X samples */
41    jornada_ts->x_data[0] = jornada_ssp_byte(TXDUMMY);
42    jornada_ts->x_data[1] = jornada_ssp_byte(TXDUMMY);
43    jornada_ts->x_data[2] = jornada_ssp_byte(TXDUMMY);
44
45    /* 3 low word Y samples */
46    jornada_ts->y_data[0] = jornada_ssp_byte(TXDUMMY);
47    jornada_ts->y_data[1] = jornada_ssp_byte(TXDUMMY);
48    jornada_ts->y_data[2] = jornada_ssp_byte(TXDUMMY);
49
50    /* combined x samples bits */
51    jornada_ts->x_data[3] = jornada_ssp_byte(TXDUMMY);
52
53    /* combined y samples bits */
54    jornada_ts->y_data[3] = jornada_ssp_byte(TXDUMMY);
55}
56
57static int jornada720_ts_average(int coords[4])
58{
59	int coord, high_bits = coords[3];
60
61	coord  = coords[0] | ((high_bits & 0x03) << 8);
62	coord += coords[1] | ((high_bits & 0x0c) << 6);
63	coord += coords[2] | ((high_bits & 0x30) << 4);
64
65	return coord / 3;
66}
67
68static irqreturn_t jornada720_ts_interrupt(int irq, void *dev_id)
69{
70	struct platform_device *pdev = dev_id;
71	struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
72	struct input_dev *input = jornada_ts->dev;
73	int x, y;
74
75	/* If GPIO_GPIO9 is set to high then report pen up */
76	if (GPLR & GPIO_GPIO(9)) {
77		input_report_key(input, BTN_TOUCH, 0);
78		input_sync(input);
79	} else {
80		jornada_ssp_start();
81
82		/* proper reply to request is always TXDUMMY */
83		if (jornada_ssp_inout(GETTOUCHSAMPLES) == TXDUMMY) {
84			jornada720_ts_collect_data(jornada_ts);
85
86			x = jornada720_ts_average(jornada_ts->x_data);
87			y = jornada720_ts_average(jornada_ts->y_data);
88
89			input_report_key(input, BTN_TOUCH, 1);
90			input_report_abs(input, ABS_X, x);
91			input_report_abs(input, ABS_Y, y);
92			input_sync(input);
93		}
94
95		jornada_ssp_end();
96	}
97
98	return IRQ_HANDLED;
99}
100
101static int __devinit jornada720_ts_probe(struct platform_device *pdev)
102{
103	struct jornada_ts *jornada_ts;
104	struct input_dev *input_dev;
105	int error;
106
107	jornada_ts = kzalloc(sizeof(struct jornada_ts), GFP_KERNEL);
108	input_dev = input_allocate_device();
109
110	if (!jornada_ts || !input_dev) {
111		error = -ENOMEM;
112		goto fail1;
113	}
114
115	platform_set_drvdata(pdev, jornada_ts);
116
117	jornada_ts->dev = input_dev;
118
119	input_dev->name = "HP Jornada 7xx Touchscreen";
120	input_dev->phys = "jornadats/input0";
121	input_dev->id.bustype = BUS_HOST;
122	input_dev->dev.parent = &pdev->dev;
123
124	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
125	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
126	input_set_abs_params(input_dev, ABS_X, 270, 3900, 0, 0);
127	input_set_abs_params(input_dev, ABS_Y, 180, 3700, 0, 0);
128
129	error = request_irq(IRQ_GPIO9,
130			jornada720_ts_interrupt,
131			IRQF_TRIGGER_RISING,
132			"HP7XX Touchscreen driver", pdev);
133	if (error) {
134		printk(KERN_INFO "HP7XX TS : Unable to acquire irq!\n");
135		goto fail1;
136	}
137
138	error = input_register_device(jornada_ts->dev);
139	if (error)
140		goto fail2;
141
142	return 0;
143
144 fail2:
145	free_irq(IRQ_GPIO9, pdev);
146 fail1:
147	platform_set_drvdata(pdev, NULL);
148	input_free_device(input_dev);
149	kfree(jornada_ts);
150	return error;
151}
152
153static int __devexit jornada720_ts_remove(struct platform_device *pdev)
154{
155	struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
156
157	free_irq(IRQ_GPIO9, pdev);
158	platform_set_drvdata(pdev, NULL);
159	input_unregister_device(jornada_ts->dev);
160	kfree(jornada_ts);
161
162	return 0;
163}
164
165/* work with hotplug and coldplug */
166MODULE_ALIAS("platform:jornada_ts");
167
168static struct platform_driver jornada720_ts_driver = {
169	.probe		= jornada720_ts_probe,
170	.remove		= __devexit_p(jornada720_ts_remove),
171	.driver		= {
172		.name	= "jornada_ts",
173		.owner	= THIS_MODULE,
174	},
175};
176module_platform_driver(jornada720_ts_driver);
177