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 | |
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(dwork: &pcap_ts->work, delay: 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(dev: pcap_ts->input, ABS_PRESSURE, value: 0); |
57 | input_report_key(dev: pcap_ts->input, BTN_TOUCH, value: 0); |
58 | |
59 | pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY; |
60 | schedule_delayed_work(dwork: &pcap_ts->work, delay: 0); |
61 | } else { |
62 | /* pen is touching the screen */ |
63 | input_report_abs(dev: pcap_ts->input, ABS_X, value: pcap_ts->x); |
64 | input_report_abs(dev: pcap_ts->input, ABS_Y, value: pcap_ts->y); |
65 | input_report_key(dev: pcap_ts->input, BTN_TOUCH, value: 1); |
66 | input_report_abs(dev: pcap_ts->input, ABS_PRESSURE, |
67 | value: 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(dwork: &pcap_ts->work, |
72 | delay: msecs_to_jiffies(SAMPLE_DELAY)); |
73 | } |
74 | input_sync(dev: 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 | |
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 | |
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(dwork: &pcap_ts->work, delay: 0); |
110 | } |
111 | return IRQ_HANDLED; |
112 | } |
113 | |
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(dwork: &pcap_ts->work, delay: 0); |
120 | |
121 | return 0; |
122 | } |
123 | |
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(dwork: &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 | |
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(size: sizeof(*pcap_ts), GFP_KERNEL); |
142 | if (!pcap_ts) |
143 | return err; |
144 | |
145 | pcap_ts->pcap = dev_get_drvdata(dev: pdev->dev.parent); |
146 | platform_set_drvdata(pdev, data: 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(dev: input_dev, data: 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(dev: input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, fuzz: 0, flat: 0); |
174 | input_set_abs_params(dev: input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, fuzz: 0, flat: 0); |
175 | input_set_abs_params(dev: input_dev, ABS_PRESSURE, PRESSURE_MIN, |
176 | PRESSURE_MAX, fuzz: 0, flat: 0); |
177 | |
178 | err = input_register_device(pcap_ts->input); |
179 | if (err) |
180 | goto fail_allocate; |
181 | |
182 | err = request_irq(irq: pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), |
183 | handler: pcap_ts_event_touch, flags: 0, name: "Touch Screen" , dev: 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(dev: input_dev); |
194 | fail: |
195 | kfree(objp: pcap_ts); |
196 | |
197 | return err; |
198 | } |
199 | |
200 | static int 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(dwork: &pcap_ts->work); |
206 | |
207 | input_unregister_device(pcap_ts->input); |
208 | |
209 | kfree(objp: pcap_ts); |
210 | |
211 | return 0; |
212 | } |
213 | |
214 | #ifdef CONFIG_PM |
215 | static int pcap_ts_suspend(struct device *dev) |
216 | { |
217 | struct pcap_ts *pcap_ts = dev_get_drvdata(dev); |
218 | |
219 | pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR); |
220 | return 0; |
221 | } |
222 | |
223 | static int pcap_ts_resume(struct device *dev) |
224 | { |
225 | struct pcap_ts *pcap_ts = dev_get_drvdata(dev); |
226 | |
227 | pcap_set_ts_bits(pcap_ts->pcap, |
228 | pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT); |
229 | return 0; |
230 | } |
231 | |
232 | static const struct dev_pm_ops pcap_ts_pm_ops = { |
233 | .suspend = pcap_ts_suspend, |
234 | .resume = pcap_ts_resume, |
235 | }; |
236 | #define PCAP_TS_PM_OPS (&pcap_ts_pm_ops) |
237 | #else |
238 | #define PCAP_TS_PM_OPS NULL |
239 | #endif |
240 | |
241 | static struct platform_driver pcap_ts_driver = { |
242 | .probe = pcap_ts_probe, |
243 | .remove = pcap_ts_remove, |
244 | .driver = { |
245 | .name = "pcap-ts" , |
246 | .pm = PCAP_TS_PM_OPS, |
247 | }, |
248 | }; |
249 | module_platform_driver(pcap_ts_driver); |
250 | |
251 | MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver" ); |
252 | MODULE_AUTHOR("Daniel Ribeiro / Harald Welte" ); |
253 | MODULE_LICENSE("GPL" ); |
254 | MODULE_ALIAS("platform:pcap_ts" ); |
255 | |