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 | |
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(dev: input_dev, slot: id); |
102 | input_mt_report_slot_state(dev: input_dev, MT_TOOL_FINGER, active: 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(dev: input_dev, ABS_MT_POSITION_X, value: x); |
109 | input_report_abs(dev: input_dev, ABS_MT_POSITION_Y, value: y); |
110 | input_report_abs(dev: input_dev, ABS_MT_PRESSURE, value: z); |
111 | } |
112 | |
113 | input_mt_report_pointer_emulation(dev: input_dev, use_count: true); |
114 | input_sync(dev: input_dev); |
115 | |
116 | return IRQ_HANDLED; |
117 | } |
118 | |
119 | /* wake up controller by an falling edge of interrupt gpio. */ |
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(dev: &client->dev, con_id: "wakeup" , flags: GPIOD_OUT_HIGH); |
127 | ret = PTR_ERR_OR_ZERO(ptr: 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(desc: gpio, value: 0); |
138 | |
139 | /* controller should be woken up, return irq. */ |
140 | gpiod_direction_input(desc: gpio); |
141 | gpiod_put(desc: gpio); |
142 | |
143 | return 0; |
144 | } |
145 | |
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, buf: cmd, MAX_I2C_DATA_LEN); |
152 | if (ret < 0) |
153 | return ret; |
154 | |
155 | return 0; |
156 | } |
157 | |
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(dev: &client->dev, size: 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(dev: input_dev, ABS_X, min: 0, EGALAX_MAX_X, fuzz: 0, flat: 0); |
198 | input_set_abs_params(dev: input_dev, ABS_Y, min: 0, EGALAX_MAX_Y, fuzz: 0, flat: 0); |
199 | input_set_abs_params(dev: input_dev, |
200 | ABS_MT_POSITION_X, min: 0, EGALAX_MAX_X, fuzz: 0, flat: 0); |
201 | input_set_abs_params(dev: input_dev, |
202 | ABS_MT_POSITION_Y, min: 0, EGALAX_MAX_Y, fuzz: 0, flat: 0); |
203 | input_mt_init_slots(dev: input_dev, MAX_SUPPORT_POINTS, flags: 0); |
204 | |
205 | error = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, |
206 | NULL, thread_fn: egalax_ts_interrupt, |
207 | IRQF_ONESHOT, devname: "egalax_ts" , dev_id: 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" , 0 }, |
222 | { } |
223 | }; |
224 | MODULE_DEVICE_TABLE(i2c, egalax_ts_id); |
225 | |
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(irq: client->irq); |
236 | |
237 | ret = i2c_master_send(client, buf: suspend_cmd, MAX_I2C_DATA_LEN); |
238 | return ret > 0 ? 0 : ret; |
239 | } |
240 | |
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(irq: 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 | |