1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Motorola PCAP2 touchscreen as found in the EZX phone platform.
4 *
5 * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
6 * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/fs.h>
11 #include <linux/string.h>
12 #include <linux/slab.h>
13 #include <linux/pm.h>
14 #include <linux/timer.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/input.h>
18 #include <linux/mfd/ezx-pcap.h>
19
20 struct pcap_ts {
21 struct pcap_chip *pcap;
22 struct input_dev *input;
23 struct delayed_work work;
24 u16 x, y;
25 u16 pressure;
26 u8 read_state;
27 };
28
29 #define SAMPLE_DELAY 20 /* msecs */
30
31 #define X_AXIS_MIN 0
32 #define X_AXIS_MAX 1023
33 #define Y_AXIS_MAX X_AXIS_MAX
34 #define Y_AXIS_MIN X_AXIS_MIN
35 #define PRESSURE_MAX X_AXIS_MAX
36 #define PRESSURE_MIN X_AXIS_MIN
37
pcap_ts_read_xy(void * data,u16 res[2])38 static void pcap_ts_read_xy(void *data, u16 res[2])
39 {
40 struct pcap_ts *pcap_ts = data;
41
42 switch (pcap_ts->read_state) {
43 case PCAP_ADC_TS_M_PRESSURE:
44 /* pressure reading is unreliable */
45 if (res[0] > PRESSURE_MIN && res[0] < PRESSURE_MAX)
46 pcap_ts->pressure = res[0];
47 pcap_ts->read_state = PCAP_ADC_TS_M_XY;
48 schedule_delayed_work(&pcap_ts->work, 0);
49 break;
50 case PCAP_ADC_TS_M_XY:
51 pcap_ts->y = res[0];
52 pcap_ts->x = res[1];
53 if (pcap_ts->x <= X_AXIS_MIN || pcap_ts->x >= X_AXIS_MAX ||
54 pcap_ts->y <= Y_AXIS_MIN || pcap_ts->y >= Y_AXIS_MAX) {
55 /* pen has been released */
56 input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
57 input_report_key(pcap_ts->input, BTN_TOUCH, 0);
58
59 pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
60 schedule_delayed_work(&pcap_ts->work, 0);
61 } else {
62 /* pen is touching the screen */
63 input_report_abs(pcap_ts->input, ABS_X, pcap_ts->x);
64 input_report_abs(pcap_ts->input, ABS_Y, pcap_ts->y);
65 input_report_key(pcap_ts->input, BTN_TOUCH, 1);
66 input_report_abs(pcap_ts->input, ABS_PRESSURE,
67 pcap_ts->pressure);
68
69 /* switch back to pressure read mode */
70 pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
71 schedule_delayed_work(&pcap_ts->work,
72 msecs_to_jiffies(SAMPLE_DELAY));
73 }
74 input_sync(pcap_ts->input);
75 break;
76 default:
77 dev_warn(&pcap_ts->input->dev,
78 "pcap_ts: Warning, unhandled read_state %d\n",
79 pcap_ts->read_state);
80 break;
81 }
82 }
83
pcap_ts_work(struct work_struct * work)84 static void pcap_ts_work(struct work_struct *work)
85 {
86 struct delayed_work *dw = to_delayed_work(work);
87 struct pcap_ts *pcap_ts = container_of(dw, struct pcap_ts, work);
88 u8 ch[2];
89
90 pcap_set_ts_bits(pcap_ts->pcap,
91 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
92
93 if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY)
94 return;
95
96 /* start adc conversion */
97 ch[0] = PCAP_ADC_CH_TS_X1;
98 ch[1] = PCAP_ADC_CH_TS_Y1;
99 pcap_adc_async(pcap_ts->pcap, PCAP_ADC_BANK_1, 0, ch,
100 pcap_ts_read_xy, pcap_ts);
101 }
102
pcap_ts_event_touch(int pirq,void * data)103 static irqreturn_t pcap_ts_event_touch(int pirq, void *data)
104 {
105 struct pcap_ts *pcap_ts = data;
106
107 if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY) {
108 pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
109 schedule_delayed_work(&pcap_ts->work, 0);
110 }
111 return IRQ_HANDLED;
112 }
113
pcap_ts_open(struct input_dev * dev)114 static int pcap_ts_open(struct input_dev *dev)
115 {
116 struct pcap_ts *pcap_ts = input_get_drvdata(dev);
117
118 pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
119 schedule_delayed_work(&pcap_ts->work, 0);
120
121 return 0;
122 }
123
pcap_ts_close(struct input_dev * dev)124 static void pcap_ts_close(struct input_dev *dev)
125 {
126 struct pcap_ts *pcap_ts = input_get_drvdata(dev);
127
128 cancel_delayed_work_sync(&pcap_ts->work);
129
130 pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
131 pcap_set_ts_bits(pcap_ts->pcap,
132 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
133 }
134
pcap_ts_probe(struct platform_device * pdev)135 static int pcap_ts_probe(struct platform_device *pdev)
136 {
137 struct input_dev *input_dev;
138 struct pcap_ts *pcap_ts;
139 int err = -ENOMEM;
140
141 pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
142 if (!pcap_ts)
143 return err;
144
145 pcap_ts->pcap = dev_get_drvdata(pdev->dev.parent);
146 platform_set_drvdata(pdev, pcap_ts);
147
148 input_dev = input_allocate_device();
149 if (!input_dev)
150 goto fail;
151
152 INIT_DELAYED_WORK(&pcap_ts->work, pcap_ts_work);
153
154 pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
155 pcap_set_ts_bits(pcap_ts->pcap,
156 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
157
158 pcap_ts->input = input_dev;
159 input_set_drvdata(input_dev, pcap_ts);
160
161 input_dev->name = "pcap-touchscreen";
162 input_dev->phys = "pcap_ts/input0";
163 input_dev->id.bustype = BUS_HOST;
164 input_dev->id.vendor = 0x0001;
165 input_dev->id.product = 0x0002;
166 input_dev->id.version = 0x0100;
167 input_dev->dev.parent = &pdev->dev;
168 input_dev->open = pcap_ts_open;
169 input_dev->close = pcap_ts_close;
170
171 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
172 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
173 input_set_abs_params(input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
174 input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
175 input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN,
176 PRESSURE_MAX, 0, 0);
177
178 err = input_register_device(pcap_ts->input);
179 if (err)
180 goto fail_allocate;
181
182 err = request_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS),
183 pcap_ts_event_touch, 0, "Touch Screen", pcap_ts);
184 if (err)
185 goto fail_register;
186
187 return 0;
188
189 fail_register:
190 input_unregister_device(input_dev);
191 goto fail;
192 fail_allocate:
193 input_free_device(input_dev);
194 fail:
195 kfree(pcap_ts);
196
197 return err;
198 }
199
pcap_ts_remove(struct platform_device * pdev)200 static void pcap_ts_remove(struct platform_device *pdev)
201 {
202 struct pcap_ts *pcap_ts = platform_get_drvdata(pdev);
203
204 free_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), pcap_ts);
205 cancel_delayed_work_sync(&pcap_ts->work);
206
207 input_unregister_device(pcap_ts->input);
208
209 kfree(pcap_ts);
210 }
211
212 #ifdef CONFIG_PM
pcap_ts_suspend(struct device * dev)213 static int pcap_ts_suspend(struct device *dev)
214 {
215 struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
216
217 pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
218 return 0;
219 }
220
pcap_ts_resume(struct device * dev)221 static int pcap_ts_resume(struct device *dev)
222 {
223 struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
224
225 pcap_set_ts_bits(pcap_ts->pcap,
226 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
227 return 0;
228 }
229
230 static const struct dev_pm_ops pcap_ts_pm_ops = {
231 .suspend = pcap_ts_suspend,
232 .resume = pcap_ts_resume,
233 };
234 #define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
235 #else
236 #define PCAP_TS_PM_OPS NULL
237 #endif
238
239 static struct platform_driver pcap_ts_driver = {
240 .probe = pcap_ts_probe,
241 .remove_new = pcap_ts_remove,
242 .driver = {
243 .name = "pcap-ts",
244 .pm = PCAP_TS_PM_OPS,
245 },
246 };
247 module_platform_driver(pcap_ts_driver);
248
249 MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
250 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
251 MODULE_LICENSE("GPL");
252 MODULE_ALIAS("platform:pcap_ts");
253