1/*
2 * PXA930 track ball mouse driver
3 *
4 * Copyright (C) 2007 Marvell International Ltd.
5 * 2008-02-28: Yong Yao <yaoyong@marvell.com>
6 *             initial version
7 *
8 *  This program is free software; you can redistribute it and/or modify
9 *  it under the terms of the GNU General Public License version 2 as
10 *  published by the Free Software Foundation.
11 */
12
13#include <linux/input.h>
14#include <linux/interrupt.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/delay.h>
18#include <linux/io.h>
19#include <linux/slab.h>
20
21#include <mach/hardware.h>
22#include <linux/platform_data/mouse-pxa930_trkball.h>
23
24/* Trackball Controller Register Definitions */
25#define TBCR		(0x000C)
26#define TBCNTR		(0x0010)
27#define TBSBC		(0x0014)
28
29#define TBCR_TBRST	(1 << 1)
30#define TBCR_TBSB	(1 << 10)
31
32#define TBCR_Y_FLT(n)	(((n) & 0xf) << 6)
33#define TBCR_X_FLT(n)	(((n) & 0xf) << 2)
34
35#define TBCNTR_YM(n)	(((n) >> 24) & 0xff)
36#define TBCNTR_YP(n)	(((n) >> 16) & 0xff)
37#define TBCNTR_XM(n)	(((n) >> 8) & 0xff)
38#define TBCNTR_XP(n)	((n) & 0xff)
39
40#define TBSBC_TBSBC	(0x1)
41
42struct pxa930_trkball {
43	struct pxa930_trkball_platform_data *pdata;
44
45	/* Memory Mapped Register */
46	struct resource *mem;
47	void __iomem *mmio_base;
48
49	struct input_dev *input;
50};
51
52static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
53{
54	struct pxa930_trkball *trkball = dev_id;
55	struct input_dev *input = trkball->input;
56	int tbcntr, x, y;
57
58	/* According to the spec software must read TBCNTR twice:
59	 * if the read value is the same, the reading is valid
60	 */
61	tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
62
63	if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
64		x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
65		y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
66
67		input_report_rel(input, REL_X, x);
68		input_report_rel(input, REL_Y, y);
69		input_sync(input);
70	}
71
72	__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
73	__raw_writel(0, trkball->mmio_base + TBSBC);
74
75	return IRQ_HANDLED;
76}
77
78/* For TBCR, we need to wait for a while to make sure it has been modified. */
79static int write_tbcr(struct pxa930_trkball *trkball, int v)
80{
81	int i = 100;
82
83	__raw_writel(v, trkball->mmio_base + TBCR);
84
85	while (--i) {
86		if (__raw_readl(trkball->mmio_base + TBCR) == v)
87			break;
88		msleep(1);
89	}
90
91	if (i == 0) {
92		pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
93		return -ETIMEDOUT;
94	}
95
96	return 0;
97}
98
99static void pxa930_trkball_config(struct pxa930_trkball *trkball)
100{
101	uint32_t tbcr;
102
103	/* According to spec, need to write the filters of x,y to 0xf first! */
104	tbcr = __raw_readl(trkball->mmio_base + TBCR);
105	write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
106	write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
107			    TBCR_Y_FLT(trkball->pdata->y_filter));
108
109	/* According to spec, set TBCR_TBRST first, before clearing it! */
110	tbcr = __raw_readl(trkball->mmio_base + TBCR);
111	write_tbcr(trkball, tbcr | TBCR_TBRST);
112	write_tbcr(trkball, tbcr & ~TBCR_TBRST);
113
114	__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
115	__raw_writel(0, trkball->mmio_base + TBSBC);
116
117	pr_debug("%s: final TBCR=%x!\n", __func__,
118		 __raw_readl(trkball->mmio_base + TBCR));
119}
120
121static int pxa930_trkball_open(struct input_dev *dev)
122{
123	struct pxa930_trkball *trkball = input_get_drvdata(dev);
124
125	pxa930_trkball_config(trkball);
126
127	return 0;
128}
129
130static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
131{
132	uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
133
134	/* Held in reset, gate the 32-KHz input clock off */
135	write_tbcr(trkball, tbcr | TBCR_TBRST);
136}
137
138static void pxa930_trkball_close(struct input_dev *dev)
139{
140	struct pxa930_trkball *trkball = input_get_drvdata(dev);
141
142	pxa930_trkball_disable(trkball);
143}
144
145static int pxa930_trkball_probe(struct platform_device *pdev)
146{
147	struct pxa930_trkball *trkball;
148	struct input_dev *input;
149	struct resource *res;
150	int irq, error;
151
152	irq = platform_get_irq(pdev, 0);
153	if (irq < 0) {
154		dev_err(&pdev->dev, "failed to get trkball irq\n");
155		return -ENXIO;
156	}
157
158	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
159	if (!res) {
160		dev_err(&pdev->dev, "failed to get register memory\n");
161		return -ENXIO;
162	}
163
164	trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
165	if (!trkball)
166		return -ENOMEM;
167
168	trkball->pdata = dev_get_platdata(&pdev->dev);
169	if (!trkball->pdata) {
170		dev_err(&pdev->dev, "no platform data defined\n");
171		error = -EINVAL;
172		goto failed;
173	}
174
175	trkball->mmio_base = ioremap_nocache(res->start, resource_size(res));
176	if (!trkball->mmio_base) {
177		dev_err(&pdev->dev, "failed to ioremap registers\n");
178		error = -ENXIO;
179		goto failed;
180	}
181
182	/* held the module in reset, will be enabled in open() */
183	pxa930_trkball_disable(trkball);
184
185	error = request_irq(irq, pxa930_trkball_interrupt, 0,
186			    pdev->name, trkball);
187	if (error) {
188		dev_err(&pdev->dev, "failed to request irq: %d\n", error);
189		goto failed_free_io;
190	}
191
192	platform_set_drvdata(pdev, trkball);
193
194	input = input_allocate_device();
195	if (!input) {
196		dev_err(&pdev->dev, "failed to allocate input device\n");
197		error = -ENOMEM;
198		goto failed_free_irq;
199	}
200
201	input->name = pdev->name;
202	input->id.bustype = BUS_HOST;
203	input->open = pxa930_trkball_open;
204	input->close = pxa930_trkball_close;
205	input->dev.parent = &pdev->dev;
206	input_set_drvdata(input, trkball);
207
208	trkball->input = input;
209
210	input_set_capability(input, EV_REL, REL_X);
211	input_set_capability(input, EV_REL, REL_Y);
212
213	error = input_register_device(input);
214	if (error) {
215		dev_err(&pdev->dev, "unable to register input device\n");
216		goto failed_free_input;
217	}
218
219	return 0;
220
221failed_free_input:
222	input_free_device(input);
223failed_free_irq:
224	free_irq(irq, trkball);
225failed_free_io:
226	iounmap(trkball->mmio_base);
227failed:
228	kfree(trkball);
229	return error;
230}
231
232static int pxa930_trkball_remove(struct platform_device *pdev)
233{
234	struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
235	int irq = platform_get_irq(pdev, 0);
236
237	input_unregister_device(trkball->input);
238	free_irq(irq, trkball);
239	iounmap(trkball->mmio_base);
240	kfree(trkball);
241
242	return 0;
243}
244
245static struct platform_driver pxa930_trkball_driver = {
246	.driver		= {
247		.name	= "pxa930-trkball",
248	},
249	.probe		= pxa930_trkball_probe,
250	.remove		= pxa930_trkball_remove,
251};
252module_platform_driver(pxa930_trkball_driver);
253
254MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
255MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
256MODULE_LICENSE("GPL");
257