aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/mouse/pxa930_trkball.c
blob: a0f45c4fc198aef847dacae8d5184972f7d54e45 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
/*
 * PXA930 track ball mouse driver
 *
 * Copyright (C) 2007 Marvell International Ltd.
 * 2008-02-28: Yong Yao <yaoyong@marvell.com>
 *             initial version
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/input.h>
#include <linux/version.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/io.h>

#include <mach/hardware.h>
#include <mach/pxa930_trkball.h>

/* Trackball Controller Register Definitions */
#define TBCR		(0x000C)
#define TBCNTR		(0x0010)
#define TBSBC		(0x0014)

#define TBCR_TBRST	(1 << 1)
#define TBCR_TBSB	(1 << 10)

#define TBCR_Y_FLT(n)	(((n) & 0xf) << 6)
#define TBCR_X_FLT(n)	(((n) & 0xf) << 2)

#define TBCNTR_YM(n)	(((n) >> 24) & 0xff)
#define TBCNTR_YP(n)	(((n) >> 16) & 0xff)
#define TBCNTR_XM(n)	(((n) >> 8) & 0xff)
#define TBCNTR_XP(n)	((n) & 0xff)

#define TBSBC_TBSBC	(0x1)

struct pxa930_trkball {
	struct pxa930_trkball_platform_data *pdata;

	/* Memory Mapped Register */
	struct resource *mem;
	void __iomem *mmio_base;

	struct input_dev *input;
};

static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
{
	struct pxa930_trkball *trkball = dev_id;
	struct input_dev *input = trkball->input;
	int tbcntr, x, y;

	/* According to the spec software must read TBCNTR twice:
	 * if the read value is the same, the reading is valid
	 */
	tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);

	if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
		x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
		y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;

		input_report_rel(input, REL_X, x);
		input_report_rel(input, REL_Y, y);
		input_sync(input);
	}

	__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
	__raw_writel(0, trkball->mmio_base + TBSBC);

	return IRQ_HANDLED;
}

/* For TBCR, we need to wait for a while to make sure it has been modified. */
static int write_tbcr(struct pxa930_trkball *trkball, int v)
{
	int i = 100;

	__raw_writel(v, trkball->mmio_base + TBCR);

	while (i--) {
		if (__raw_readl(trkball->mmio_base + TBCR) == v)
			break;
		msleep(1);
	}

	if (i == 0) {
		pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
		return -ETIMEDOUT;
	}

	return 0;
}

static void pxa930_trkball_config(struct pxa930_trkball *trkball)
{
	uint32_t tbcr;

	/* According to spec, need to write the filters of x,y to 0xf first! */
	tbcr = __raw_readl(trkball->mmio_base + TBCR);
	write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
	write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
			    TBCR_Y_FLT(trkball->pdata->y_filter));

	/* According to spec, set TBCR_TBRST first, before clearing it! */
	tbcr = __raw_readl(trkball->mmio_base + TBCR);
	write_tbcr(trkball, tbcr | TBCR_TBRST);
	write_tbcr(trkball, tbcr & ~TBCR_TBRST);

	__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
	__raw_writel(0, trkball->mmio_base + TBSBC);

	pr_debug("%s: final TBCR=%x!\n", __func__,
		 __raw_readl(trkball->mmio_base + TBCR));
}

static int pxa930_trkball_open(struct input_dev *dev)
{
	struct pxa930_trkball *trkball = input_get_drvdata(dev);

	pxa930_trkball_config(trkball);

	return 0;
}

static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
{
	uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);

	/* Held in reset, gate the 32-KHz input clock off */
	write_tbcr(trkball, tbcr | TBCR_TBRST);
}

static void pxa930_trkball_close(struct input_dev *dev)
{
	struct pxa930_trkball *trkball = input_get_drvdata(dev);

	pxa930_trkball_disable(trkball);
}

static int __devinit pxa930_trkball_probe(struct platform_device *pdev)
{
	struct pxa930_trkball *trkball;
	struct input_dev *input;
	struct resource *res;
	int irq, error;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "failed to get trkball irq\n");
		return -ENXIO;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "failed to get register memory\n");
		return -ENXIO;
	}

	trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
	if (!trkball)
		return -ENOMEM;

	trkball->pdata = pdev->dev.platform_data;
	if (!trkball->pdata) {
		dev_err(&pdev->dev, "no platform data defined\n");
		error = -EINVAL;
		goto failed;
	}

	trkball->mmio_base = ioremap_nocache(res->start, resource_size(res));
	if (!trkball->mmio_base) {
		dev_err(&pdev->dev, "failed to ioremap registers\n");
		error = -ENXIO;
		goto failed;
	}

	/* held the module in reset, will be enabled in open() */
	pxa930_trkball_disable(trkball);

	error = request_irq(irq, pxa930_trkball_interrupt, IRQF_DISABLED,
			    pdev->name, trkball);
	if (error) {
		dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
		goto failed_free_io;
	}

	platform_set_drvdata(pdev, trkball);

	input = input_allocate_device();
	if (!input) {
		dev_err(&pdev->dev, "failed to allocate input device\n");
		error = -ENOMEM;
		goto failed_free_irq;
	}

	input->name = pdev->name;
	input->id.bustype = BUS_HOST;
	input->open = pxa930_trkball_open;
	input->close = pxa930_trkball_close;
	input->dev.parent = &pdev->dev;
	input_set_drvdata(input, trkball);

	trkball->input = input;

	input_set_capability(input, EV_REL, REL_X);
	input_set_capability(input, EV_REL, REL_Y);

	error = input_register_device(input);
	if (error) {
		dev_err(&pdev->dev, "unable to register input device\n");
		goto failed_free_input;
	}

	return 0;

failed_free_input:
	input_free_device(input);
failed_free_irq:
	free_irq(irq, trkball);
failed_free_io:
	iounmap(trkball->mmio_base);
failed:
	kfree(trkball);
	return ret;
}

static int __devexit pxa930_trkball_remove(struct platform_device *pdev)
{
	struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	input_unregister_device(trkball->input);
	free_irq(irq, trkball);
	iounmap(trkball->mmio_base);
	kfree(trkball);

	return 0;
}

static struct platform_driver pxa930_trkball_driver = {
	.driver		= {
		.name	= "pxa930-trkball",
	},
	.probe		= pxa930_trkball_probe,
	.remove		= __devexit_p(pxa930_trkball_remove),
};

static int __init pxa930_trkball_init(void)
{
	return platform_driver_register(&pxa930_trkball_driver);
}

static void __exit pxa930_trkball_exit(void)
{
	platform_driver_unregister(&pxa930_trkball_driver);
}

module_init(pxa930_trkball_init);
module_exit(pxa930_trkball_exit);

MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
MODULE_LICENSE("GPL");