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authorSascha Hauer <s.hauer@pengutronix.de>2009-12-15 11:48:57 -0500
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2009-12-15 11:54:51 -0500
commitd201fd5dfb22801b6b012bb9f58cd186e4690d98 (patch)
tree54224db95f01d41674f2ccc9b87cecbcdf151ce3 /drivers/input/touchscreen/mc13783_ts.c
parent60214f058f44cfaa38db2abf0b42d4436c31aa58 (diff)
Input: add mc13783 touchscreen driver
This driver provides support for the touchscreen interface integrated into the Freescale MC13783. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Luotao Fu <l.fu@pengutronix.de> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/touchscreen/mc13783_ts.c')
-rw-r--r--drivers/input/touchscreen/mc13783_ts.c258
1 files changed, 258 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/mc13783_ts.c b/drivers/input/touchscreen/mc13783_ts.c
new file mode 100644
index 000000000000..be115b3b65eb
--- /dev/null
+++ b/drivers/input/touchscreen/mc13783_ts.c
@@ -0,0 +1,258 @@
1/*
2 * Driver for the Freescale Semiconductor MC13783 touchscreen.
3 *
4 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
5 * Copyright (C) 2009 Sascha Hauer, Pengutronix
6 *
7 * Initial development of this code was funded by
8 * Phytec Messtechnik GmbH, http://www.phytec.de/
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published by
12 * the Free Software Foundation.
13 */
14#include <linux/platform_device.h>
15#include <linux/mfd/mc13783.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/input.h>
19#include <linux/sched.h>
20#include <linux/init.h>
21
22#define MC13783_TS_NAME "mc13783-ts"
23
24#define DEFAULT_SAMPLE_TOLERANCE 300
25
26static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE;
27module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR);
28MODULE_PARM_DESC(sample_tolerance,
29 "If the minimal and maximal value read out for one axis (out "
30 "of three) differ by this value (default: "
31 __stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading "
32 "is supposed to be wrong and is discarded. Set to 0 to "
33 "disable this check.");
34
35struct mc13783_ts_priv {
36 struct input_dev *idev;
37 struct mc13783 *mc13783;
38 struct delayed_work work;
39 struct workqueue_struct *workq;
40 unsigned int sample[4];
41};
42
43static irqreturn_t mc13783_ts_handler(int irq, void *data)
44{
45 struct mc13783_ts_priv *priv = data;
46
47 mc13783_ackirq(priv->mc13783, irq);
48
49 /*
50 * Kick off reading coordinates. Note that if work happens already
51 * be queued for future execution (it rearms itself) it will not
52 * be rescheduled for immediate execution here. However the rearm
53 * delay is HZ / 50 which is acceptable.
54 */
55 queue_delayed_work(priv->workq, &priv->work, 0);
56
57 return IRQ_HANDLED;
58}
59
60#define sort3(a0, a1, a2) ({ \
61 if (a0 > a1) \
62 swap(a0, a1); \
63 if (a1 > a2) \
64 swap(a1, a2); \
65 if (a0 > a1) \
66 swap(a0, a1); \
67 })
68
69static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
70{
71 struct input_dev *idev = priv->idev;
72 int x0, x1, x2, y0, y1, y2;
73 int cr0, cr1;
74
75 /*
76 * the values are 10-bit wide only, but the two least significant
77 * bits are for future 12 bit use and reading yields 0
78 */
79 x0 = priv->sample[0] & 0xfff;
80 x1 = priv->sample[1] & 0xfff;
81 x2 = priv->sample[2] & 0xfff;
82 y0 = priv->sample[3] & 0xfff;
83 y1 = (priv->sample[0] >> 12) & 0xfff;
84 y2 = (priv->sample[1] >> 12) & 0xfff;
85 cr0 = (priv->sample[2] >> 12) & 0xfff;
86 cr1 = (priv->sample[3] >> 12) & 0xfff;
87
88 dev_dbg(&idev->dev,
89 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
90 x0, x1, x2, y0, y1, y2, cr0, cr1);
91
92 sort3(x0, x1, x2);
93 sort3(y0, y1, y2);
94
95 cr0 = (cr0 + cr1) / 2;
96
97 if (!cr0 || !sample_tolerance ||
98 (x2 - x0 < sample_tolerance &&
99 y2 - y0 < sample_tolerance)) {
100 /* report the median coordinate and average pressure */
101 if (cr0) {
102 input_report_abs(idev, ABS_X, x1);
103 input_report_abs(idev, ABS_Y, y1);
104
105 dev_dbg(&idev->dev, "report (%d, %d, %d)\n",
106 x1, y1, 0x1000 - cr0);
107 queue_delayed_work(priv->workq, &priv->work, HZ / 50);
108 } else
109 dev_dbg(&idev->dev, "report release\n");
110
111 input_report_abs(idev, ABS_PRESSURE,
112 cr0 ? 0x1000 - cr0 : cr0);
113 input_report_key(idev, BTN_TOUCH, cr0);
114 input_sync(idev);
115 } else
116 dev_dbg(&idev->dev, "discard event\n");
117}
118
119static void mc13783_ts_work(struct work_struct *work)
120{
121 struct mc13783_ts_priv *priv =
122 container_of(work, struct mc13783_ts_priv, work.work);
123 unsigned int mode = MC13783_ADC_MODE_TS;
124 unsigned int channel = 12;
125
126 if (mc13783_adc_do_conversion(priv->mc13783,
127 mode, channel, priv->sample) == 0)
128 mc13783_ts_report_sample(priv);
129}
130
131static int mc13783_ts_open(struct input_dev *dev)
132{
133 struct mc13783_ts_priv *priv = input_get_drvdata(dev);
134 int ret;
135
136 mc13783_lock(priv->mc13783);
137
138 mc13783_ackirq(priv->mc13783, MC13783_IRQ_TS);
139
140 ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_TS,
141 mc13783_ts_handler, MC13783_TS_NAME, priv);
142 if (ret)
143 goto out;
144
145 ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
146 MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0);
147 if (ret)
148 mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
149out:
150 mc13783_unlock(priv->mc13783);
151 return ret;
152}
153
154static void mc13783_ts_close(struct input_dev *dev)
155{
156 struct mc13783_ts_priv *priv = input_get_drvdata(dev);
157
158 mc13783_lock(priv->mc13783);
159 mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
160 MC13783_ADC0_TSMOD_MASK, 0);
161 mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
162 mc13783_unlock(priv->mc13783);
163
164 cancel_delayed_work_sync(&priv->work);
165}
166
167static int __init mc13783_ts_probe(struct platform_device *pdev)
168{
169 struct mc13783_ts_priv *priv;
170 struct input_dev *idev;
171 int ret = -ENOMEM;
172
173 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
174 idev = input_allocate_device();
175 if (!priv || !idev)
176 goto err_free_mem;
177
178 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
179 priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
180 priv->idev = idev;
181
182 /*
183 * We need separate workqueue because mc13783_adc_do_conversion
184 * uses keventd and thus would deadlock.
185 */
186 priv->workq = create_singlethread_workqueue("mc13783_ts");
187 if (!priv->workq)
188 goto err_free_mem;
189
190 idev->name = MC13783_TS_NAME;
191 idev->dev.parent = &pdev->dev;
192
193 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
194 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
195 input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
196 input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
197 input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0);
198
199 idev->open = mc13783_ts_open;
200 idev->close = mc13783_ts_close;
201
202 input_set_drvdata(idev, priv);
203
204 ret = input_register_device(priv->idev);
205 if (ret) {
206 dev_err(&pdev->dev,
207 "register input device failed with %d\n", ret);
208 goto err_destroy_wq;
209 }
210
211 platform_set_drvdata(pdev, priv);
212 return 0;
213
214err_destroy_wq:
215 destroy_workqueue(priv->workq);
216err_free_mem:
217 input_free_device(idev);
218 kfree(priv);
219 return ret;
220}
221
222static int __devexit mc13783_ts_remove(struct platform_device *pdev)
223{
224 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
225
226 platform_set_drvdata(pdev, NULL);
227
228 destroy_workqueue(priv->workq);
229 input_unregister_device(priv->idev);
230 kfree(priv);
231
232 return 0;
233}
234
235static struct platform_driver mc13783_ts_driver = {
236 .remove = __devexit_p(mc13783_ts_remove),
237 .driver = {
238 .owner = THIS_MODULE,
239 .name = MC13783_TS_NAME,
240 },
241};
242
243static int __init mc13783_ts_init(void)
244{
245 return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe);
246}
247module_init(mc13783_ts_init);
248
249static void __exit mc13783_ts_exit(void)
250{
251 platform_driver_unregister(&mc13783_ts_driver);
252}
253module_exit(mc13783_ts_exit);
254
255MODULE_DESCRIPTION("MC13783 input touchscreen driver");
256MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
257MODULE_LICENSE("GPL v2");
258MODULE_ALIAS("platform:" MC13783_TS_NAME);