1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for EETI eGalax Multiple Touch Controller
4 *
5 * Copyright (C) 2011 Freescale Semiconductor, Inc.
6 *
7 * based on max11801_ts.c
8 */
9
10 /* EETI eGalax serial touch screen controller is a I2C based multiple
11 * touch screen controller, it supports 5 point multiple touch. */
12
13 /* TODO:
14 - auto idle mode support
15 */
16
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/i2c.h>
20 #include <linux/interrupt.h>
21 #include <linux/input.h>
22 #include <linux/irq.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/bitops.h>
27 #include <linux/input/mt.h>
28
29 /*
30 * Mouse Mode: some panel may configure the controller to mouse mode,
31 * which can only report one point at a given time.
32 * This driver will ignore events in this mode.
33 */
34 #define REPORT_MODE_MOUSE 0x1
35 /*
36 * Vendor Mode: this mode is used to transfer some vendor specific
37 * messages.
38 * This driver will ignore events in this mode.
39 */
40 #define REPORT_MODE_VENDOR 0x3
41 /* Multiple Touch Mode */
42 #define REPORT_MODE_MTTOUCH 0x4
43
44 #define MAX_SUPPORT_POINTS 5
45
46 #define EVENT_VALID_OFFSET 7
47 #define EVENT_VALID_MASK (0x1 << EVENT_VALID_OFFSET)
48 #define EVENT_ID_OFFSET 2
49 #define EVENT_ID_MASK (0xf << EVENT_ID_OFFSET)
50 #define EVENT_IN_RANGE (0x1 << 1)
51 #define EVENT_DOWN_UP (0X1 << 0)
52
53 #define MAX_I2C_DATA_LEN 10
54
55 #define EGALAX_MAX_X 32760
56 #define EGALAX_MAX_Y 32760
57 #define EGALAX_MAX_TRIES 100
58
59 struct egalax_ts {
60 struct i2c_client *client;
61 struct input_dev *input_dev;
62 };
63
egalax_ts_interrupt(int irq,void * dev_id)64 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
65 {
66 struct egalax_ts *ts = dev_id;
67 struct input_dev *input_dev = ts->input_dev;
68 struct i2c_client *client = ts->client;
69 u8 buf[MAX_I2C_DATA_LEN];
70 int id, ret, x, y, z;
71 int tries = 0;
72 bool down, valid;
73 u8 state;
74
75 do {
76 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
77 } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
78
79 if (ret < 0)
80 return IRQ_HANDLED;
81
82 if (buf[0] != REPORT_MODE_MTTOUCH) {
83 /* ignore mouse events and vendor events */
84 return IRQ_HANDLED;
85 }
86
87 state = buf[1];
88 x = (buf[3] << 8) | buf[2];
89 y = (buf[5] << 8) | buf[4];
90 z = (buf[7] << 8) | buf[6];
91
92 valid = state & EVENT_VALID_MASK;
93 id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
94 down = state & EVENT_DOWN_UP;
95
96 if (!valid || id > MAX_SUPPORT_POINTS) {
97 dev_dbg(&client->dev, "point invalid\n");
98 return IRQ_HANDLED;
99 }
100
101 input_mt_slot(input_dev, id);
102 input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
103
104 dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
105 down ? "down" : "up", id, x, y, z);
106
107 if (down) {
108 input_report_abs(input_dev, ABS_MT_POSITION_X, x);
109 input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
110 input_report_abs(input_dev, ABS_MT_PRESSURE, z);
111 }
112
113 input_mt_report_pointer_emulation(input_dev, true);
114 input_sync(input_dev);
115
116 return IRQ_HANDLED;
117 }
118
119 /* wake up controller by an falling edge of interrupt gpio. */
egalax_wake_up_device(struct i2c_client * client)120 static int egalax_wake_up_device(struct i2c_client *client)
121 {
122 struct gpio_desc *gpio;
123 int ret;
124
125 /* wake up controller via an falling edge on IRQ gpio. */
126 gpio = gpiod_get(&client->dev, "wakeup", GPIOD_OUT_HIGH);
127 ret = PTR_ERR_OR_ZERO(gpio);
128 if (ret) {
129 if (ret != -EPROBE_DEFER)
130 dev_err(&client->dev,
131 "failed to request wakeup gpio, cannot wake up controller: %d\n",
132 ret);
133 return ret;
134 }
135
136 /* release the line */
137 gpiod_set_value_cansleep(gpio, 0);
138
139 /* controller should be woken up, return irq. */
140 gpiod_direction_input(gpio);
141 gpiod_put(gpio);
142
143 return 0;
144 }
145
egalax_firmware_version(struct i2c_client * client)146 static int egalax_firmware_version(struct i2c_client *client)
147 {
148 static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
149 int ret;
150
151 ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
152 if (ret < 0)
153 return ret;
154
155 return 0;
156 }
157
egalax_ts_probe(struct i2c_client * client)158 static int egalax_ts_probe(struct i2c_client *client)
159 {
160 struct egalax_ts *ts;
161 struct input_dev *input_dev;
162 int error;
163
164 ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
165 if (!ts) {
166 dev_err(&client->dev, "Failed to allocate memory\n");
167 return -ENOMEM;
168 }
169
170 input_dev = devm_input_allocate_device(&client->dev);
171 if (!input_dev) {
172 dev_err(&client->dev, "Failed to allocate memory\n");
173 return -ENOMEM;
174 }
175
176 ts->client = client;
177 ts->input_dev = input_dev;
178
179 /* controller may be in sleep, wake it up. */
180 error = egalax_wake_up_device(client);
181 if (error)
182 return error;
183
184 error = egalax_firmware_version(client);
185 if (error < 0) {
186 dev_err(&client->dev, "Failed to read firmware version\n");
187 return error;
188 }
189
190 input_dev->name = "EETI eGalax Touch Screen";
191 input_dev->id.bustype = BUS_I2C;
192
193 __set_bit(EV_ABS, input_dev->evbit);
194 __set_bit(EV_KEY, input_dev->evbit);
195 __set_bit(BTN_TOUCH, input_dev->keybit);
196
197 input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
198 input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
199 input_set_abs_params(input_dev,
200 ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
201 input_set_abs_params(input_dev,
202 ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
203 input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
204
205 error = devm_request_threaded_irq(&client->dev, client->irq,
206 NULL, egalax_ts_interrupt,
207 IRQF_ONESHOT, "egalax_ts", ts);
208 if (error < 0) {
209 dev_err(&client->dev, "Failed to register interrupt\n");
210 return error;
211 }
212
213 error = input_register_device(ts->input_dev);
214 if (error)
215 return error;
216
217 return 0;
218 }
219
220 static const struct i2c_device_id egalax_ts_id[] = {
221 { "egalax_ts" },
222 { }
223 };
224 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
225
egalax_ts_suspend(struct device * dev)226 static int egalax_ts_suspend(struct device *dev)
227 {
228 static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
229 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
230 };
231 struct i2c_client *client = to_i2c_client(dev);
232 int ret;
233
234 if (device_may_wakeup(dev))
235 return enable_irq_wake(client->irq);
236
237 ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
238 return ret > 0 ? 0 : ret;
239 }
240
egalax_ts_resume(struct device * dev)241 static int egalax_ts_resume(struct device *dev)
242 {
243 struct i2c_client *client = to_i2c_client(dev);
244
245 if (device_may_wakeup(dev))
246 return disable_irq_wake(client->irq);
247
248 return egalax_wake_up_device(client);
249 }
250
251 static DEFINE_SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops,
252 egalax_ts_suspend, egalax_ts_resume);
253
254 static const struct of_device_id egalax_ts_dt_ids[] = {
255 { .compatible = "eeti,egalax_ts" },
256 { /* sentinel */ }
257 };
258 MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
259
260 static struct i2c_driver egalax_ts_driver = {
261 .driver = {
262 .name = "egalax_ts",
263 .pm = pm_sleep_ptr(&egalax_ts_pm_ops),
264 .of_match_table = egalax_ts_dt_ids,
265 },
266 .id_table = egalax_ts_id,
267 .probe = egalax_ts_probe,
268 };
269
270 module_i2c_driver(egalax_ts_driver);
271
272 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
273 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
274 MODULE_LICENSE("GPL");
275