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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 mc13xxx_irq_ack(priv->mc13xxx, irq);
46
47
48
49
50
51
52
53 schedule_delayed_work(&priv->work, 0);
54
55 return IRQ_HANDLED;
56}
57
58#define sort3(a0, a1, a2) ({ \
59 if (a0 > a1) \
60 swap(a0, a1); \
61 if (a1 > a2) \
62 swap(a1, a2); \
63 if (a0 > a1) \
64 swap(a0, a1); \
65 })
66
67static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
68{
69 struct input_dev *idev = priv->idev;
70 int x0, x1, x2, y0, y1, y2;
71 int cr0, cr1;
72
73
74
75
76
77 x0 = priv->sample[0] & 0xfff;
78 x1 = priv->sample[1] & 0xfff;
79 x2 = priv->sample[2] & 0xfff;
80 y0 = priv->sample[3] & 0xfff;
81 y1 = (priv->sample[0] >> 12) & 0xfff;
82 y2 = (priv->sample[1] >> 12) & 0xfff;
83 cr0 = (priv->sample[2] >> 12) & 0xfff;
84 cr1 = (priv->sample[3] >> 12) & 0xfff;
85
86 dev_dbg(&idev->dev,
87 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
88 x0, x1, x2, y0, y1, y2, cr0, cr1);
89
90 sort3(x0, x1, x2);
91 sort3(y0, y1, y2);
92
93 cr0 = (cr0 + cr1) / 2;
94
95 if (!cr0 || !sample_tolerance ||
96 (x2 - x0 < sample_tolerance &&
97 y2 - y0 < sample_tolerance)) {
98
99 if (cr0) {
100 input_report_abs(idev, ABS_X, x1);
101 input_report_abs(idev, ABS_Y, y1);
102
103 dev_dbg(&idev->dev, "report (%d, %d, %d)\n",
104 x1, y1, 0x1000 - cr0);
105 schedule_delayed_work(&priv->work, HZ / 50);
106 } else {
107 dev_dbg(&idev->dev, "report release\n");
108 }
109
110 input_report_abs(idev, ABS_PRESSURE,
111 cr0 ? 0x1000 - cr0 : cr0);
112 input_report_key(idev, BTN_TOUCH, cr0);
113 input_sync(idev);
114 } else {
115 dev_dbg(&idev->dev, "discard event\n");
116 }
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 = MC13XXX_ADC_MODE_TS;
124 unsigned int channel = 12;
125
126 if (mc13xxx_adc_do_conversion(priv->mc13xxx,
127 mode, channel,
128 priv->touch->ato, priv->touch->atox,
129 priv->sample) == 0)
130 mc13783_ts_report_sample(priv);
131}
132
133static int mc13783_ts_open(struct input_dev *dev)
134{
135 struct mc13783_ts_priv *priv = input_get_drvdata(dev);
136 int ret;
137
138 mc13xxx_lock(priv->mc13xxx);
139
140 mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS);
141
142 ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS,
143 mc13783_ts_handler, MC13783_TS_NAME, priv);
144 if (ret)
145 goto out;
146
147 ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
148 MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0);
149 if (ret)
150 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
151out:
152 mc13xxx_unlock(priv->mc13xxx);
153 return ret;
154}
155
156static void mc13783_ts_close(struct input_dev *dev)
157{
158 struct mc13783_ts_priv *priv = input_get_drvdata(dev);
159
160 mc13xxx_lock(priv->mc13xxx);
161 mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
162 MC13XXX_ADC0_TSMOD_MASK, 0);
163 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
164 mc13xxx_unlock(priv->mc13xxx);
165
166 cancel_delayed_work_sync(&priv->work);
167}
168
169static int __init mc13783_ts_probe(struct platform_device *pdev)
170{
171 struct mc13783_ts_priv *priv;
172 struct input_dev *idev;
173 int ret = -ENOMEM;
174
175 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
176 idev = input_allocate_device();
177 if (!priv || !idev)
178 goto err_free_mem;
179
180 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
181 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
182 priv->idev = idev;
183 priv->touch = dev_get_platdata(&pdev->dev);
184 if (!priv->touch) {
185 dev_err(&pdev->dev, "missing platform data\n");
186 ret = -ENODEV;
187 goto err_free_mem;
188 }
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_free_mem;
209 }
210
211 platform_set_drvdata(pdev, priv);
212 return 0;
213
214err_free_mem:
215 input_free_device(idev);
216 kfree(priv);
217 return ret;
218}
219
220static int mc13783_ts_remove(struct platform_device *pdev)
221{
222 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
223
224 input_unregister_device(priv->idev);
225 kfree(priv);
226
227 return 0;
228}
229
230static struct platform_driver mc13783_ts_driver = {
231 .remove = mc13783_ts_remove,
232 .driver = {
233 .name = MC13783_TS_NAME,
234 },
235};
236
237module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe);
238
239MODULE_DESCRIPTION("MC13783 input touchscreen driver");
240MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
241MODULE_LICENSE("GPL v2");
242MODULE_ALIAS("platform:" MC13783_TS_NAME);
243
