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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for the Freescale Semiconductor MC13783 touchscreen.
4 *
5 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
6 * Copyright (C) 2009 Sascha Hauer, Pengutronix
7 *
8 * Initial development of this code was funded by
9 * Phytec Messtechnik GmbH, http://www.phytec.de/
10 */
11#include <linux/platform_device.h>
12#include <linux/mfd/mc13783.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/input.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/init.h>
19
20#define MC13783_TS_NAME "mc13783-ts"
21
22#define DEFAULT_SAMPLE_TOLERANCE 300
23
24static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE;
25module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR);
26MODULE_PARM_DESC(sample_tolerance,
27 "If the minimal and maximal value read out for one axis (out "
28 "of three) differ by this value (default: "
29 __stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading "
30 "is supposed to be wrong and is discarded. Set to 0 to "
31 "disable this check.");
32
33struct mc13783_ts_priv {
34 struct input_dev *idev;
35 struct mc13xxx *mc13xxx;
36 struct delayed_work work;
37 unsigned int sample[4];
38 struct mc13xxx_ts_platform_data *touch;
39};
40
41static irqreturn_t mc13783_ts_handler(int irq, void *data)
42{
43 struct mc13783_ts_priv *priv = data;
44
45 /*
46 * Kick off reading coordinates. Note that if work happens already
47 * be queued for future execution (it rearms itself) it will not
48 * be rescheduled for immediate execution here. However the rearm
49 * delay is HZ / 50 which is acceptable.
50 */
51 schedule_delayed_work(&priv->work, 0);
52
53 return IRQ_HANDLED;
54}
55
56#define sort3(a0, a1, a2) ({ \
57 if (a0 > a1) \
58 swap(a0, a1); \
59 if (a1 > a2) \
60 swap(a1, a2); \
61 if (a0 > a1) \
62 swap(a0, a1); \
63 })
64
65static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
66{
67 struct input_dev *idev = priv->idev;
68 int x0, x1, x2, y0, y1, y2;
69 int cr0, cr1;
70
71 /*
72 * the values are 10-bit wide only, but the two least significant
73 * bits are for future 12 bit use and reading yields 0
74 */
75 x0 = priv->sample[0] & 0xfff;
76 x1 = priv->sample[1] & 0xfff;
77 x2 = priv->sample[2] & 0xfff;
78 y0 = priv->sample[3] & 0xfff;
79 y1 = (priv->sample[0] >> 12) & 0xfff;
80 y2 = (priv->sample[1] >> 12) & 0xfff;
81 cr0 = (priv->sample[2] >> 12) & 0xfff;
82 cr1 = (priv->sample[3] >> 12) & 0xfff;
83
84 dev_dbg(&idev->dev,
85 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
86 x0, x1, x2, y0, y1, y2, cr0, cr1);
87
88 sort3(x0, x1, x2);
89 sort3(y0, y1, y2);
90
91 cr0 = (cr0 + cr1) / 2;
92
93 if (!cr0 || !sample_tolerance ||
94 (x2 - x0 < sample_tolerance &&
95 y2 - y0 < sample_tolerance)) {
96 /* report the median coordinate and average pressure */
97 if (cr0) {
98 input_report_abs(idev, ABS_X, x1);
99 input_report_abs(idev, ABS_Y, y1);
100
101 dev_dbg(&idev->dev, "report (%d, %d, %d)\n",
102 x1, y1, 0x1000 - cr0);
103 schedule_delayed_work(&priv->work, HZ / 50);
104 } else {
105 dev_dbg(&idev->dev, "report release\n");
106 }
107
108 input_report_abs(idev, ABS_PRESSURE,
109 cr0 ? 0x1000 - cr0 : cr0);
110 input_report_key(idev, BTN_TOUCH, cr0);
111 input_sync(idev);
112 } else {
113 dev_dbg(&idev->dev, "discard event\n");
114 }
115}
116
117static void mc13783_ts_work(struct work_struct *work)
118{
119 struct mc13783_ts_priv *priv =
120 container_of(work, struct mc13783_ts_priv, work.work);
121 unsigned int mode = MC13XXX_ADC_MODE_TS;
122 unsigned int channel = 12;
123
124 if (mc13xxx_adc_do_conversion(priv->mc13xxx,
125 mode, channel,
126 priv->touch->ato, priv->touch->atox,
127 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 mc13xxx_lock(priv->mc13xxx);
137
138 ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS,
139 mc13783_ts_handler, MC13783_TS_NAME, priv);
140 if (ret)
141 goto out;
142
143 ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
144 MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0);
145 if (ret)
146 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
147out:
148 mc13xxx_unlock(priv->mc13xxx);
149 return ret;
150}
151
152static void mc13783_ts_close(struct input_dev *dev)
153{
154 struct mc13783_ts_priv *priv = input_get_drvdata(dev);
155
156 mc13xxx_lock(priv->mc13xxx);
157 mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
158 MC13XXX_ADC0_TSMOD_MASK, 0);
159 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
160 mc13xxx_unlock(priv->mc13xxx);
161
162 cancel_delayed_work_sync(&priv->work);
163}
164
165static int __init mc13783_ts_probe(struct platform_device *pdev)
166{
167 struct mc13783_ts_priv *priv;
168 struct input_dev *idev;
169 int ret = -ENOMEM;
170
171 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
172 idev = input_allocate_device();
173 if (!priv || !idev)
174 goto err_free_mem;
175
176 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
177 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
178 priv->idev = idev;
179 priv->touch = dev_get_platdata(&pdev->dev);
180 if (!priv->touch) {
181 dev_err(&pdev->dev, "missing platform data\n");
182 ret = -ENODEV;
183 goto err_free_mem;
184 }
185
186 idev->name = MC13783_TS_NAME;
187 idev->dev.parent = &pdev->dev;
188
189 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
190 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
191 input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
192 input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
193 input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0);
194
195 idev->open = mc13783_ts_open;
196 idev->close = mc13783_ts_close;
197
198 input_set_drvdata(idev, priv);
199
200 ret = input_register_device(priv->idev);
201 if (ret) {
202 dev_err(&pdev->dev,
203 "register input device failed with %d\n", ret);
204 goto err_free_mem;
205 }
206
207 platform_set_drvdata(pdev, priv);
208 return 0;
209
210err_free_mem:
211 input_free_device(idev);
212 kfree(priv);
213 return ret;
214}
215
216static void mc13783_ts_remove(struct platform_device *pdev)
217{
218 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
219
220 input_unregister_device(priv->idev);
221 kfree(priv);
222}
223
224static struct platform_driver mc13783_ts_driver = {
225 .remove = mc13783_ts_remove,
226 .driver = {
227 .name = MC13783_TS_NAME,
228 },
229};
230
231module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe);
232
233MODULE_DESCRIPTION("MC13783 input touchscreen driver");
234MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
235MODULE_LICENSE("GPL v2");
236MODULE_ALIAS("platform:" MC13783_TS_NAME);