1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Driver for ChipOne icn8318 i2c touchscreen controller
4 *
5 * Copyright (c) 2015 Red Hat Inc.
6 *
7 * Red Hat authors:
8 * Hans de Goede <hdegoede@redhat.com>
9 */
10
11 #include <linux/gpio/consumer.h>
12 #include <linux/interrupt.h>
13 #include <linux/i2c.h>
14 #include <linux/input.h>
15 #include <linux/input/mt.h>
16 #include <linux/input/touchscreen.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19
20 #define ICN8318_REG_POWER 4
21 #define ICN8318_REG_TOUCHDATA 16
22
23 #define ICN8318_POWER_ACTIVE 0
24 #define ICN8318_POWER_MONITOR 1
25 #define ICN8318_POWER_HIBERNATE 2
26
27 #define ICN8318_MAX_TOUCHES 5
28
29 struct icn8318_touch {
30 __u8 slot;
31 __be16 x;
32 __be16 y;
33 __u8 pressure; /* Seems more like finger width then pressure really */
34 __u8 event;
35 /* The difference between 2 and 3 is unclear */
36 #define ICN8318_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */
37 #define ICN8318_EVENT_UPDATE1 2 /* New or updated coordinates */
38 #define ICN8318_EVENT_UPDATE2 3 /* New or updated coordinates */
39 #define ICN8318_EVENT_END 4 /* Finger lifted */
40 } __packed;
41
42 struct icn8318_touch_data {
43 __u8 softbutton;
44 __u8 touch_count;
45 struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
46 } __packed;
47
48 struct icn8318_data {
49 struct i2c_client *client;
50 struct input_dev *input;
51 struct gpio_desc *wake_gpio;
52 struct touchscreen_properties prop;
53 };
54
icn8318_read_touch_data(struct i2c_client * client,struct icn8318_touch_data * touch_data)55 static int icn8318_read_touch_data(struct i2c_client *client,
56 struct icn8318_touch_data *touch_data)
57 {
58 u8 reg = ICN8318_REG_TOUCHDATA;
59 struct i2c_msg msg[2] = {
60 {
61 .addr = client->addr,
62 .len = 1,
63 .buf = ®
64 },
65 {
66 .addr = client->addr,
67 .flags = I2C_M_RD,
68 .len = sizeof(struct icn8318_touch_data),
69 .buf = (u8 *)touch_data
70 }
71 };
72
73 return i2c_transfer(client->adapter, msg, 2);
74 }
75
icn8318_touch_active(u8 event)76 static inline bool icn8318_touch_active(u8 event)
77 {
78 return (event == ICN8318_EVENT_UPDATE1) ||
79 (event == ICN8318_EVENT_UPDATE2);
80 }
81
icn8318_irq(int irq,void * dev_id)82 static irqreturn_t icn8318_irq(int irq, void *dev_id)
83 {
84 struct icn8318_data *data = dev_id;
85 struct device *dev = &data->client->dev;
86 struct icn8318_touch_data touch_data;
87 int i, ret;
88
89 ret = icn8318_read_touch_data(data->client, &touch_data);
90 if (ret < 0) {
91 dev_err(dev, "Error reading touch data: %d\n", ret);
92 return IRQ_HANDLED;
93 }
94
95 if (touch_data.softbutton) {
96 /*
97 * Other data is invalid when a softbutton is pressed.
98 * This needs some extra devicetree bindings to map the icn8318
99 * softbutton codes to evdev codes. Currently no known devices
100 * use this.
101 */
102 return IRQ_HANDLED;
103 }
104
105 if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
106 dev_warn(dev, "Too much touches %d > %d\n",
107 touch_data.touch_count, ICN8318_MAX_TOUCHES);
108 touch_data.touch_count = ICN8318_MAX_TOUCHES;
109 }
110
111 for (i = 0; i < touch_data.touch_count; i++) {
112 struct icn8318_touch *touch = &touch_data.touches[i];
113 bool act = icn8318_touch_active(touch->event);
114
115 input_mt_slot(data->input, touch->slot);
116 input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
117 if (!act)
118 continue;
119
120 touchscreen_report_pos(data->input, &data->prop,
121 be16_to_cpu(touch->x),
122 be16_to_cpu(touch->y), true);
123 }
124
125 input_mt_sync_frame(data->input);
126 input_sync(data->input);
127
128 return IRQ_HANDLED;
129 }
130
icn8318_start(struct input_dev * dev)131 static int icn8318_start(struct input_dev *dev)
132 {
133 struct icn8318_data *data = input_get_drvdata(dev);
134
135 enable_irq(data->client->irq);
136 gpiod_set_value_cansleep(data->wake_gpio, 1);
137
138 return 0;
139 }
140
icn8318_stop(struct input_dev * dev)141 static void icn8318_stop(struct input_dev *dev)
142 {
143 struct icn8318_data *data = input_get_drvdata(dev);
144
145 disable_irq(data->client->irq);
146 i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
147 ICN8318_POWER_HIBERNATE);
148 gpiod_set_value_cansleep(data->wake_gpio, 0);
149 }
150
151 #ifdef CONFIG_PM_SLEEP
icn8318_suspend(struct device * dev)152 static int icn8318_suspend(struct device *dev)
153 {
154 struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
155
156 mutex_lock(&data->input->mutex);
157 if (data->input->users)
158 icn8318_stop(data->input);
159 mutex_unlock(&data->input->mutex);
160
161 return 0;
162 }
163
icn8318_resume(struct device * dev)164 static int icn8318_resume(struct device *dev)
165 {
166 struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
167
168 mutex_lock(&data->input->mutex);
169 if (data->input->users)
170 icn8318_start(data->input);
171 mutex_unlock(&data->input->mutex);
172
173 return 0;
174 }
175 #endif
176
177 static SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);
178
icn8318_probe(struct i2c_client * client,const struct i2c_device_id * id)179 static int icn8318_probe(struct i2c_client *client,
180 const struct i2c_device_id *id)
181 {
182 struct device *dev = &client->dev;
183 struct icn8318_data *data;
184 struct input_dev *input;
185 int error;
186
187 if (!client->irq) {
188 dev_err(dev, "Error no irq specified\n");
189 return -EINVAL;
190 }
191
192 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
193 if (!data)
194 return -ENOMEM;
195
196 data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
197 if (IS_ERR(data->wake_gpio)) {
198 error = PTR_ERR(data->wake_gpio);
199 if (error != -EPROBE_DEFER)
200 dev_err(dev, "Error getting wake gpio: %d\n", error);
201 return error;
202 }
203
204 input = devm_input_allocate_device(dev);
205 if (!input)
206 return -ENOMEM;
207
208 input->name = client->name;
209 input->id.bustype = BUS_I2C;
210 input->open = icn8318_start;
211 input->close = icn8318_stop;
212 input->dev.parent = dev;
213
214 input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
215 input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
216
217 touchscreen_parse_properties(input, true, &data->prop);
218 if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
219 !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
220 dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
221 return -EINVAL;
222 }
223
224 error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
225 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
226 if (error)
227 return error;
228
229 data->client = client;
230 data->input = input;
231 input_set_drvdata(input, data);
232
233 error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
234 IRQF_ONESHOT, client->name, data);
235 if (error) {
236 dev_err(dev, "Error requesting irq: %d\n", error);
237 return error;
238 }
239
240 /* Stop device till opened */
241 icn8318_stop(data->input);
242
243 error = input_register_device(input);
244 if (error)
245 return error;
246
247 i2c_set_clientdata(client, data);
248
249 return 0;
250 }
251
252 static const struct of_device_id icn8318_of_match[] = {
253 { .compatible = "chipone,icn8318" },
254 { }
255 };
256 MODULE_DEVICE_TABLE(of, icn8318_of_match);
257
258 /* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
259 static const struct i2c_device_id icn8318_i2c_id[] = {
260 { },
261 };
262 MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);
263
264 static struct i2c_driver icn8318_driver = {
265 .driver = {
266 .name = "chipone_icn8318",
267 .pm = &icn8318_pm_ops,
268 .of_match_table = icn8318_of_match,
269 },
270 .probe = icn8318_probe,
271 .id_table = icn8318_i2c_id,
272 };
273
274 module_i2c_driver(icn8318_driver);
275
276 MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
277 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
278 MODULE_LICENSE("GPL");
279
