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/string_choices.h>
27#include <linux/bitops.h>
28#include <linux/input/mt.h>
29
30/*
31 * Mouse Mode: some panel may configure the controller to mouse mode,
32 * which can only report one point at a given time.
33 * This driver will ignore events in this mode.
34 */
35#define REPORT_MODE_MOUSE 0x1
36/*
37 * Vendor Mode: this mode is used to transfer some vendor specific
38 * messages.
39 * This driver will ignore events in this mode.
40 */
41#define REPORT_MODE_VENDOR 0x3
42/* Multiple Touch Mode */
43#define REPORT_MODE_MTTOUCH 0x4
44
45#define MAX_SUPPORT_POINTS 5
46
47#define EVENT_VALID_OFFSET 7
48#define EVENT_VALID_MASK (0x1 << EVENT_VALID_OFFSET)
49#define EVENT_ID_OFFSET 2
50#define EVENT_ID_MASK (0xf << EVENT_ID_OFFSET)
51#define EVENT_IN_RANGE (0x1 << 1)
52#define EVENT_DOWN_UP (0X1 << 0)
53
54#define MAX_I2C_DATA_LEN 10
55
56#define EGALAX_MAX_X 32760
57#define EGALAX_MAX_Y 32760
58#define EGALAX_MAX_TRIES 100
59
60struct egalax_ts {
61 struct i2c_client *client;
62 struct input_dev *input_dev;
63};
64
65static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
66{
67 struct egalax_ts *ts = dev_id;
68 struct input_dev *input_dev = ts->input_dev;
69 struct i2c_client *client = ts->client;
70 u8 buf[MAX_I2C_DATA_LEN];
71 int id, ret, x, y, z;
72 int tries = 0;
73 bool down, valid;
74 u8 state;
75
76 do {
77 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
78 } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
79
80 if (ret < 0)
81 return IRQ_HANDLED;
82
83 if (buf[0] != REPORT_MODE_MTTOUCH) {
84 /* ignore mouse events and vendor events */
85 return IRQ_HANDLED;
86 }
87
88 state = buf[1];
89 x = (buf[3] << 8) | buf[2];
90 y = (buf[5] << 8) | buf[4];
91 z = (buf[7] << 8) | buf[6];
92
93 valid = state & EVENT_VALID_MASK;
94 id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
95 down = state & EVENT_DOWN_UP;
96
97 if (!valid || id > MAX_SUPPORT_POINTS) {
98 dev_dbg(&client->dev, "point invalid\n");
99 return IRQ_HANDLED;
100 }
101
102 input_mt_slot(dev: input_dev, slot: id);
103 input_mt_report_slot_state(dev: input_dev, MT_TOOL_FINGER, active: down);
104
105 dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
106 str_down_up(down), id, x, y, z);
107
108 if (down) {
109 input_report_abs(dev: input_dev, ABS_MT_POSITION_X, value: x);
110 input_report_abs(dev: input_dev, ABS_MT_POSITION_Y, value: y);
111 input_report_abs(dev: input_dev, ABS_MT_PRESSURE, value: z);
112 }
113
114 input_mt_report_pointer_emulation(dev: input_dev, use_count: true);
115 input_sync(dev: input_dev);
116
117 return IRQ_HANDLED;
118}
119
120/* wake up controller by an falling edge of interrupt gpio. */
121static int egalax_wake_up_device(struct i2c_client *client)
122{
123 struct gpio_desc *gpio;
124 int ret;
125
126 /* wake up controller via an falling edge on IRQ gpio. */
127 gpio = gpiod_get(dev: &client->dev, con_id: "wakeup", flags: GPIOD_OUT_HIGH);
128 ret = PTR_ERR_OR_ZERO(ptr: gpio);
129 if (ret) {
130 if (ret != -EPROBE_DEFER)
131 dev_err(&client->dev,
132 "failed to request wakeup gpio, cannot wake up controller: %d\n",
133 ret);
134 return ret;
135 }
136
137 /* release the line */
138 gpiod_set_value_cansleep(desc: gpio, value: 0);
139
140 /* controller should be woken up, return irq. */
141 gpiod_direction_input(desc: gpio);
142 gpiod_put(desc: gpio);
143
144 return 0;
145}
146
147static int egalax_firmware_version(struct i2c_client *client)
148{
149 static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
150 int ret;
151
152 ret = i2c_master_send(client, buf: cmd, MAX_I2C_DATA_LEN);
153 if (ret < 0)
154 return ret;
155
156 return 0;
157}
158
159static int egalax_ts_probe(struct i2c_client *client)
160{
161 struct egalax_ts *ts;
162 struct input_dev *input_dev;
163 int error;
164
165 ts = devm_kzalloc(dev: &client->dev, size: sizeof(struct egalax_ts), GFP_KERNEL);
166 if (!ts) {
167 dev_err(&client->dev, "Failed to allocate memory\n");
168 return -ENOMEM;
169 }
170
171 input_dev = devm_input_allocate_device(&client->dev);
172 if (!input_dev) {
173 dev_err(&client->dev, "Failed to allocate memory\n");
174 return -ENOMEM;
175 }
176
177 ts->client = client;
178 ts->input_dev = input_dev;
179
180 /* controller may be in sleep, wake it up. */
181 error = egalax_wake_up_device(client);
182 if (error)
183 return error;
184
185 error = egalax_firmware_version(client);
186 if (error < 0) {
187 dev_err(&client->dev, "Failed to read firmware version\n");
188 return error;
189 }
190
191 input_dev->name = "EETI eGalax Touch Screen";
192 input_dev->id.bustype = BUS_I2C;
193
194 __set_bit(EV_ABS, input_dev->evbit);
195 __set_bit(EV_KEY, input_dev->evbit);
196 __set_bit(BTN_TOUCH, input_dev->keybit);
197
198 input_set_abs_params(dev: input_dev, ABS_X, min: 0, EGALAX_MAX_X, fuzz: 0, flat: 0);
199 input_set_abs_params(dev: input_dev, ABS_Y, min: 0, EGALAX_MAX_Y, fuzz: 0, flat: 0);
200 input_set_abs_params(dev: input_dev,
201 ABS_MT_POSITION_X, min: 0, EGALAX_MAX_X, fuzz: 0, flat: 0);
202 input_set_abs_params(dev: input_dev,
203 ABS_MT_POSITION_Y, min: 0, EGALAX_MAX_Y, fuzz: 0, flat: 0);
204 input_mt_init_slots(dev: input_dev, MAX_SUPPORT_POINTS, flags: 0);
205
206 error = devm_request_threaded_irq(dev: &client->dev, irq: client->irq,
207 NULL, thread_fn: egalax_ts_interrupt,
208 IRQF_ONESHOT, devname: "egalax_ts", dev_id: ts);
209 if (error < 0) {
210 dev_err(&client->dev, "Failed to register interrupt\n");
211 return error;
212 }
213
214 error = input_register_device(ts->input_dev);
215 if (error)
216 return error;
217
218 return 0;
219}
220
221static const struct i2c_device_id egalax_ts_id[] = {
222 { "egalax_ts" },
223 { }
224};
225MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
226
227static int egalax_ts_suspend(struct device *dev)
228{
229 static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
230 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
231 };
232 struct i2c_client *client = to_i2c_client(dev);
233 int ret;
234
235 if (device_may_wakeup(dev))
236 return enable_irq_wake(irq: client->irq);
237
238 ret = i2c_master_send(client, buf: suspend_cmd, MAX_I2C_DATA_LEN);
239 return ret > 0 ? 0 : ret;
240}
241
242static int egalax_ts_resume(struct device *dev)
243{
244 struct i2c_client *client = to_i2c_client(dev);
245
246 if (device_may_wakeup(dev))
247 return disable_irq_wake(irq: client->irq);
248
249 return egalax_wake_up_device(client);
250}
251
252static DEFINE_SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops,
253 egalax_ts_suspend, egalax_ts_resume);
254
255static const struct of_device_id egalax_ts_dt_ids[] = {
256 { .compatible = "eeti,egalax_ts" },
257 { /* sentinel */ }
258};
259MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
260
261static struct i2c_driver egalax_ts_driver = {
262 .driver = {
263 .name = "egalax_ts",
264 .pm = pm_sleep_ptr(&egalax_ts_pm_ops),
265 .of_match_table = egalax_ts_dt_ids,
266 },
267 .id_table = egalax_ts_id,
268 .probe = egalax_ts_probe,
269};
270
271module_i2c_driver(egalax_ts_driver);
272
273MODULE_AUTHOR("Freescale Semiconductor, Inc.");
274MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
275MODULE_LICENSE("GPL");
276

source code of linux/drivers/input/touchscreen/egalax_ts.c