1 /*
2 * Driver for Motorola PCAP2 touchscreen as found in the EZX phone platform.
3 *
4 * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
5 * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/fs.h>
16 #include <linux/string.h>
17 #include <linux/slab.h>
18 #include <linux/pm.h>
19 #include <linux/timer.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22 #include <linux/input.h>
23 #include <linux/mfd/ezx-pcap.h>
24
25 struct pcap_ts {
26 struct pcap_chip *pcap;
27 struct input_dev *input;
28 struct delayed_work work;
29 u16 x, y;
30 u16 pressure;
31 u8 read_state;
32 };
33
34 #define SAMPLE_DELAY 20 /* msecs */
35
36 #define X_AXIS_MIN 0
37 #define X_AXIS_MAX 1023
38 #define Y_AXIS_MAX X_AXIS_MAX
39 #define Y_AXIS_MIN X_AXIS_MIN
40 #define PRESSURE_MAX X_AXIS_MAX
41 #define PRESSURE_MIN X_AXIS_MIN
42
pcap_ts_read_xy(void * data,u16 res[2])43 static void pcap_ts_read_xy(void *data, u16 res[2])
44 {
45 struct pcap_ts *pcap_ts = data;
46
47 switch (pcap_ts->read_state) {
48 case PCAP_ADC_TS_M_PRESSURE:
49 /* pressure reading is unreliable */
50 if (res[0] > PRESSURE_MIN && res[0] < PRESSURE_MAX)
51 pcap_ts->pressure = res[0];
52 pcap_ts->read_state = PCAP_ADC_TS_M_XY;
53 schedule_delayed_work(&pcap_ts->work, 0);
54 break;
55 case PCAP_ADC_TS_M_XY:
56 pcap_ts->y = res[0];
57 pcap_ts->x = res[1];
58 if (pcap_ts->x <= X_AXIS_MIN || pcap_ts->x >= X_AXIS_MAX ||
59 pcap_ts->y <= Y_AXIS_MIN || pcap_ts->y >= Y_AXIS_MAX) {
60 /* pen has been released */
61 input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
62 input_report_key(pcap_ts->input, BTN_TOUCH, 0);
63
64 pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
65 schedule_delayed_work(&pcap_ts->work, 0);
66 } else {
67 /* pen is touching the screen */
68 input_report_abs(pcap_ts->input, ABS_X, pcap_ts->x);
69 input_report_abs(pcap_ts->input, ABS_Y, pcap_ts->y);
70 input_report_key(pcap_ts->input, BTN_TOUCH, 1);
71 input_report_abs(pcap_ts->input, ABS_PRESSURE,
72 pcap_ts->pressure);
73
74 /* switch back to pressure read mode */
75 pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
76 schedule_delayed_work(&pcap_ts->work,
77 msecs_to_jiffies(SAMPLE_DELAY));
78 }
79 input_sync(pcap_ts->input);
80 break;
81 default:
82 dev_warn(&pcap_ts->input->dev,
83 "pcap_ts: Warning, unhandled read_state %d\n",
84 pcap_ts->read_state);
85 break;
86 }
87 }
88
pcap_ts_work(struct work_struct * work)89 static void pcap_ts_work(struct work_struct *work)
90 {
91 struct delayed_work *dw = container_of(work, struct delayed_work, work);
92 struct pcap_ts *pcap_ts = container_of(dw, struct pcap_ts, work);
93 u8 ch[2];
94
95 pcap_set_ts_bits(pcap_ts->pcap,
96 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
97
98 if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY)
99 return;
100
101 /* start adc conversion */
102 ch[0] = PCAP_ADC_CH_TS_X1;
103 ch[1] = PCAP_ADC_CH_TS_Y1;
104 pcap_adc_async(pcap_ts->pcap, PCAP_ADC_BANK_1, 0, ch,
105 pcap_ts_read_xy, pcap_ts);
106 }
107
pcap_ts_event_touch(int pirq,void * data)108 static irqreturn_t pcap_ts_event_touch(int pirq, void *data)
109 {
110 struct pcap_ts *pcap_ts = data;
111
112 if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY) {
113 pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
114 schedule_delayed_work(&pcap_ts->work, 0);
115 }
116 return IRQ_HANDLED;
117 }
118
pcap_ts_open(struct input_dev * dev)119 static int pcap_ts_open(struct input_dev *dev)
120 {
121 struct pcap_ts *pcap_ts = input_get_drvdata(dev);
122
123 pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
124 schedule_delayed_work(&pcap_ts->work, 0);
125
126 return 0;
127 }
128
pcap_ts_close(struct input_dev * dev)129 static void pcap_ts_close(struct input_dev *dev)
130 {
131 struct pcap_ts *pcap_ts = input_get_drvdata(dev);
132
133 cancel_delayed_work_sync(&pcap_ts->work);
134
135 pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
136 pcap_set_ts_bits(pcap_ts->pcap,
137 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
138 }
139
pcap_ts_probe(struct platform_device * pdev)140 static int __devinit pcap_ts_probe(struct platform_device *pdev)
141 {
142 struct input_dev *input_dev;
143 struct pcap_ts *pcap_ts;
144 int err = -ENOMEM;
145
146 pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
147 if (!pcap_ts)
148 return err;
149
150 pcap_ts->pcap = dev_get_drvdata(pdev->dev.parent);
151 platform_set_drvdata(pdev, pcap_ts);
152
153 input_dev = input_allocate_device();
154 if (!input_dev)
155 goto fail;
156
157 INIT_DELAYED_WORK(&pcap_ts->work, pcap_ts_work);
158
159 pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
160 pcap_set_ts_bits(pcap_ts->pcap,
161 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
162
163 pcap_ts->input = input_dev;
164 input_set_drvdata(input_dev, pcap_ts);
165
166 input_dev->name = "pcap-touchscreen";
167 input_dev->phys = "pcap_ts/input0";
168 input_dev->id.bustype = BUS_HOST;
169 input_dev->id.vendor = 0x0001;
170 input_dev->id.product = 0x0002;
171 input_dev->id.version = 0x0100;
172 input_dev->dev.parent = &pdev->dev;
173 input_dev->open = pcap_ts_open;
174 input_dev->close = pcap_ts_close;
175
176 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
177 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
178 input_set_abs_params(input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
179 input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
180 input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN,
181 PRESSURE_MAX, 0, 0);
182
183 err = input_register_device(pcap_ts->input);
184 if (err)
185 goto fail_allocate;
186
187 err = request_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS),
188 pcap_ts_event_touch, 0, "Touch Screen", pcap_ts);
189 if (err)
190 goto fail_register;
191
192 return 0;
193
194 fail_register:
195 input_unregister_device(input_dev);
196 goto fail;
197 fail_allocate:
198 input_free_device(input_dev);
199 fail:
200 kfree(pcap_ts);
201
202 return err;
203 }
204
pcap_ts_remove(struct platform_device * pdev)205 static int __devexit pcap_ts_remove(struct platform_device *pdev)
206 {
207 struct pcap_ts *pcap_ts = platform_get_drvdata(pdev);
208
209 free_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), pcap_ts);
210 cancel_delayed_work_sync(&pcap_ts->work);
211
212 input_unregister_device(pcap_ts->input);
213
214 kfree(pcap_ts);
215
216 return 0;
217 }
218
219 #ifdef CONFIG_PM
pcap_ts_suspend(struct device * dev)220 static int pcap_ts_suspend(struct device *dev)
221 {
222 struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
223
224 pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
225 return 0;
226 }
227
pcap_ts_resume(struct device * dev)228 static int pcap_ts_resume(struct device *dev)
229 {
230 struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
231
232 pcap_set_ts_bits(pcap_ts->pcap,
233 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
234 return 0;
235 }
236
237 static const struct dev_pm_ops pcap_ts_pm_ops = {
238 .suspend = pcap_ts_suspend,
239 .resume = pcap_ts_resume,
240 };
241 #define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
242 #else
243 #define PCAP_TS_PM_OPS NULL
244 #endif
245
246 static struct platform_driver pcap_ts_driver = {
247 .probe = pcap_ts_probe,
248 .remove = __devexit_p(pcap_ts_remove),
249 .driver = {
250 .name = "pcap-ts",
251 .owner = THIS_MODULE,
252 .pm = PCAP_TS_PM_OPS,
253 },
254 };
255 module_platform_driver(pcap_ts_driver);
256
257 MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
258 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
259 MODULE_LICENSE("GPL");
260 MODULE_ALIAS("platform:pcap_ts");
261