1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Driver for ELAN eKTF2127 i2c touchscreen controller |
4 | * |
5 | * For this driver the layout of the Chipone icn8318 i2c |
6 | * touchscreencontroller is used. |
7 | * |
8 | * Author: |
9 | * Michel Verlaan <michel.verl@gmail.com> |
10 | * Siebren Vroegindeweij <siebren.vroegindeweij@hotmail.com> |
11 | * |
12 | * Original chipone_icn8318 driver: |
13 | * Hans de Goede <hdegoede@redhat.com> |
14 | */ |
15 | |
16 | #include <linux/gpio/consumer.h> |
17 | #include <linux/interrupt.h> |
18 | #include <linux/i2c.h> |
19 | #include <linux/input.h> |
20 | #include <linux/input/mt.h> |
21 | #include <linux/input/touchscreen.h> |
22 | #include <linux/module.h> |
23 | #include <linux/of.h> |
24 | #include <linux/delay.h> |
25 | |
26 | /* Packet header defines (first byte of data send / received) */ |
27 | #define EKTF2127_NOISE 0x40 |
28 | #define EKTF2127_RESPONSE 0x52 |
29 | #define EKTF2127_REQUEST 0x53 |
30 | #define EKTF2127_HELLO 0x55 |
31 | #define EKTF2127_REPORT2 0x5a |
32 | #define EKTF2127_REPORT 0x5d |
33 | #define EKTF2127_CALIB_DONE 0x66 |
34 | |
35 | /* Register defines (second byte of data send / received) */ |
36 | #define EKTF2127_ENV_NOISY 0x41 |
37 | #define EKTF2127_HEIGHT 0x60 |
38 | #define EKTF2127_WIDTH 0x63 |
39 | |
40 | /* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */ |
41 | #define EKTF2127_TOUCH_REPORT_SIZE 21 |
42 | #define EKTF2127_MAX_TOUCHES 5 |
43 | |
44 | struct ektf2127_ts { |
45 | struct i2c_client *client; |
46 | struct input_dev *input; |
47 | struct gpio_desc *power_gpios; |
48 | struct touchscreen_properties prop; |
49 | }; |
50 | |
51 | static void ektf2127_parse_coordinates(const u8 *buf, unsigned int touch_count, |
52 | struct input_mt_pos *touches) |
53 | { |
54 | int index = 0; |
55 | int i; |
56 | |
57 | for (i = 0; i < touch_count; i++) { |
58 | index = 2 + i * 3; |
59 | |
60 | touches[i].x = (buf[index] & 0x0f); |
61 | touches[i].x <<= 8; |
62 | touches[i].x |= buf[index + 2]; |
63 | |
64 | touches[i].y = (buf[index] & 0xf0); |
65 | touches[i].y <<= 4; |
66 | touches[i].y |= buf[index + 1]; |
67 | } |
68 | } |
69 | |
70 | static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf) |
71 | { |
72 | struct input_mt_pos touches[EKTF2127_MAX_TOUCHES]; |
73 | int slots[EKTF2127_MAX_TOUCHES]; |
74 | unsigned int touch_count, i; |
75 | |
76 | touch_count = buf[1] & 0x07; |
77 | if (touch_count > EKTF2127_MAX_TOUCHES) { |
78 | dev_err(&ts->client->dev, |
79 | "Too many touches %d > %d\n" , |
80 | touch_count, EKTF2127_MAX_TOUCHES); |
81 | touch_count = EKTF2127_MAX_TOUCHES; |
82 | } |
83 | |
84 | ektf2127_parse_coordinates(buf, touch_count, touches); |
85 | input_mt_assign_slots(dev: ts->input, slots, pos: touches, |
86 | num_pos: touch_count, dmax: 0); |
87 | |
88 | for (i = 0; i < touch_count; i++) { |
89 | input_mt_slot(dev: ts->input, slot: slots[i]); |
90 | input_mt_report_slot_state(dev: ts->input, MT_TOOL_FINGER, active: true); |
91 | touchscreen_report_pos(input: ts->input, prop: &ts->prop, |
92 | x: touches[i].x, y: touches[i].y, multitouch: true); |
93 | } |
94 | |
95 | input_mt_sync_frame(dev: ts->input); |
96 | input_sync(dev: ts->input); |
97 | } |
98 | |
99 | static void ektf2127_report2_contact(struct ektf2127_ts *ts, int slot, |
100 | const u8 *buf, bool active) |
101 | { |
102 | input_mt_slot(dev: ts->input, slot); |
103 | input_mt_report_slot_state(dev: ts->input, MT_TOOL_FINGER, active); |
104 | |
105 | if (active) { |
106 | int x = (buf[0] & 0xf0) << 4 | buf[1]; |
107 | int y = (buf[0] & 0x0f) << 8 | buf[2]; |
108 | |
109 | touchscreen_report_pos(input: ts->input, prop: &ts->prop, x, y, multitouch: true); |
110 | } |
111 | } |
112 | |
113 | static void ektf2127_report2_event(struct ektf2127_ts *ts, const u8 *buf) |
114 | { |
115 | ektf2127_report2_contact(ts, slot: 0, buf: &buf[1], active: !!(buf[7] & 2)); |
116 | ektf2127_report2_contact(ts, slot: 1, buf: &buf[4], active: !!(buf[7] & 4)); |
117 | |
118 | input_mt_sync_frame(dev: ts->input); |
119 | input_sync(dev: ts->input); |
120 | } |
121 | |
122 | static irqreturn_t ektf2127_irq(int irq, void *dev_id) |
123 | { |
124 | struct ektf2127_ts *ts = dev_id; |
125 | struct device *dev = &ts->client->dev; |
126 | char buf[EKTF2127_TOUCH_REPORT_SIZE]; |
127 | int ret; |
128 | |
129 | ret = i2c_master_recv(client: ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE); |
130 | if (ret != EKTF2127_TOUCH_REPORT_SIZE) { |
131 | dev_err(dev, "Error reading touch data: %d\n" , ret); |
132 | goto out; |
133 | } |
134 | |
135 | switch (buf[0]) { |
136 | case EKTF2127_REPORT: |
137 | ektf2127_report_event(ts, buf); |
138 | break; |
139 | |
140 | case EKTF2127_REPORT2: |
141 | ektf2127_report2_event(ts, buf); |
142 | break; |
143 | |
144 | case EKTF2127_NOISE: |
145 | if (buf[1] == EKTF2127_ENV_NOISY) |
146 | dev_dbg(dev, "Environment is electrically noisy\n" ); |
147 | break; |
148 | |
149 | case EKTF2127_HELLO: |
150 | case EKTF2127_CALIB_DONE: |
151 | break; |
152 | |
153 | default: |
154 | dev_err(dev, "Unexpected packet header byte %#02x\n" , buf[0]); |
155 | break; |
156 | } |
157 | |
158 | out: |
159 | return IRQ_HANDLED; |
160 | } |
161 | |
162 | static int ektf2127_start(struct input_dev *dev) |
163 | { |
164 | struct ektf2127_ts *ts = input_get_drvdata(dev); |
165 | |
166 | enable_irq(irq: ts->client->irq); |
167 | gpiod_set_value_cansleep(desc: ts->power_gpios, value: 1); |
168 | |
169 | return 0; |
170 | } |
171 | |
172 | static void ektf2127_stop(struct input_dev *dev) |
173 | { |
174 | struct ektf2127_ts *ts = input_get_drvdata(dev); |
175 | |
176 | disable_irq(irq: ts->client->irq); |
177 | gpiod_set_value_cansleep(desc: ts->power_gpios, value: 0); |
178 | } |
179 | |
180 | static int ektf2127_suspend(struct device *dev) |
181 | { |
182 | struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); |
183 | |
184 | mutex_lock(&ts->input->mutex); |
185 | if (input_device_enabled(dev: ts->input)) |
186 | ektf2127_stop(dev: ts->input); |
187 | mutex_unlock(lock: &ts->input->mutex); |
188 | |
189 | return 0; |
190 | } |
191 | |
192 | static int ektf2127_resume(struct device *dev) |
193 | { |
194 | struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); |
195 | |
196 | mutex_lock(&ts->input->mutex); |
197 | if (input_device_enabled(dev: ts->input)) |
198 | ektf2127_start(dev: ts->input); |
199 | mutex_unlock(lock: &ts->input->mutex); |
200 | |
201 | return 0; |
202 | } |
203 | |
204 | static DEFINE_SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend, |
205 | ektf2127_resume); |
206 | |
207 | static int ektf2127_query_dimension(struct i2c_client *client, bool width) |
208 | { |
209 | struct device *dev = &client->dev; |
210 | const char *what = width ? "width" : "height" ; |
211 | u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; |
212 | u8 buf[4]; |
213 | int ret; |
214 | int error; |
215 | |
216 | /* Request dimension */ |
217 | buf[0] = EKTF2127_REQUEST; |
218 | buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; |
219 | buf[2] = 0x00; |
220 | buf[3] = 0x00; |
221 | ret = i2c_master_send(client, buf, count: sizeof(buf)); |
222 | if (ret != sizeof(buf)) { |
223 | error = ret < 0 ? ret : -EIO; |
224 | dev_err(dev, "Failed to request %s: %d\n" , what, error); |
225 | return error; |
226 | } |
227 | |
228 | msleep(msecs: 20); |
229 | |
230 | /* Read response */ |
231 | ret = i2c_master_recv(client, buf, count: sizeof(buf)); |
232 | if (ret != sizeof(buf)) { |
233 | error = ret < 0 ? ret : -EIO; |
234 | dev_err(dev, "Failed to receive %s data: %d\n" , what, error); |
235 | return error; |
236 | } |
237 | |
238 | if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) { |
239 | dev_err(dev, "Unexpected %s data: %#02x %#02x\n" , |
240 | what, buf[0], buf[1]); |
241 | return -EIO; |
242 | } |
243 | |
244 | return (((buf[3] & 0xf0) << 4) | buf[2]) - 1; |
245 | } |
246 | |
247 | static int ektf2127_probe(struct i2c_client *client) |
248 | { |
249 | struct device *dev = &client->dev; |
250 | struct ektf2127_ts *ts; |
251 | struct input_dev *input; |
252 | u8 buf[4]; |
253 | int max_x, max_y; |
254 | int error; |
255 | |
256 | if (!client->irq) { |
257 | dev_err(dev, "Error no irq specified\n" ); |
258 | return -EINVAL; |
259 | } |
260 | |
261 | ts = devm_kzalloc(dev, size: sizeof(*ts), GFP_KERNEL); |
262 | if (!ts) |
263 | return -ENOMEM; |
264 | |
265 | /* This requests the gpio *and* turns on the touchscreen controller */ |
266 | ts->power_gpios = devm_gpiod_get(dev, con_id: "power" , flags: GPIOD_OUT_HIGH); |
267 | if (IS_ERR(ptr: ts->power_gpios)) |
268 | return dev_err_probe(dev, err: PTR_ERR(ptr: ts->power_gpios), fmt: "Error getting power gpio\n" ); |
269 | |
270 | input = devm_input_allocate_device(dev); |
271 | if (!input) |
272 | return -ENOMEM; |
273 | |
274 | input->name = client->name; |
275 | input->id.bustype = BUS_I2C; |
276 | input->open = ektf2127_start; |
277 | input->close = ektf2127_stop; |
278 | |
279 | ts->client = client; |
280 | |
281 | /* Read hello (ignore result, depends on initial power state) */ |
282 | msleep(msecs: 20); |
283 | i2c_master_recv(client: ts->client, buf, count: sizeof(buf)); |
284 | |
285 | /* Read resolution from chip */ |
286 | max_x = ektf2127_query_dimension(client, width: true); |
287 | if (max_x < 0) |
288 | return max_x; |
289 | |
290 | max_y = ektf2127_query_dimension(client, width: false); |
291 | if (max_y < 0) |
292 | return max_y; |
293 | |
294 | input_set_abs_params(dev: input, ABS_MT_POSITION_X, min: 0, max: max_x, fuzz: 0, flat: 0); |
295 | input_set_abs_params(dev: input, ABS_MT_POSITION_Y, min: 0, max: max_y, fuzz: 0, flat: 0); |
296 | touchscreen_parse_properties(input, multitouch: true, prop: &ts->prop); |
297 | |
298 | error = input_mt_init_slots(dev: input, EKTF2127_MAX_TOUCHES, |
299 | INPUT_MT_DIRECT | |
300 | INPUT_MT_DROP_UNUSED | |
301 | INPUT_MT_TRACK); |
302 | if (error) |
303 | return error; |
304 | |
305 | ts->input = input; |
306 | input_set_drvdata(dev: input, data: ts); |
307 | |
308 | error = devm_request_threaded_irq(dev, irq: client->irq, |
309 | NULL, thread_fn: ektf2127_irq, |
310 | IRQF_ONESHOT, devname: client->name, dev_id: ts); |
311 | if (error) { |
312 | dev_err(dev, "Error requesting irq: %d\n" , error); |
313 | return error; |
314 | } |
315 | |
316 | /* Stop device till opened */ |
317 | ektf2127_stop(dev: ts->input); |
318 | |
319 | error = input_register_device(input); |
320 | if (error) |
321 | return error; |
322 | |
323 | i2c_set_clientdata(client, data: ts); |
324 | |
325 | return 0; |
326 | } |
327 | |
328 | #ifdef CONFIG_OF |
329 | static const struct of_device_id ektf2127_of_match[] = { |
330 | { .compatible = "elan,ektf2127" }, |
331 | { .compatible = "elan,ektf2132" }, |
332 | {} |
333 | }; |
334 | MODULE_DEVICE_TABLE(of, ektf2127_of_match); |
335 | #endif |
336 | |
337 | static const struct i2c_device_id ektf2127_i2c_id[] = { |
338 | { "ektf2127" , 0 }, |
339 | { "ektf2132" , 0 }, |
340 | {} |
341 | }; |
342 | MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id); |
343 | |
344 | static struct i2c_driver ektf2127_driver = { |
345 | .driver = { |
346 | .name = "elan_ektf2127" , |
347 | .pm = pm_sleep_ptr(&ektf2127_pm_ops), |
348 | .of_match_table = of_match_ptr(ektf2127_of_match), |
349 | }, |
350 | .probe = ektf2127_probe, |
351 | .id_table = ektf2127_i2c_id, |
352 | }; |
353 | module_i2c_driver(ektf2127_driver); |
354 | |
355 | MODULE_DESCRIPTION("ELAN eKTF2127/eKTF2132 I2C Touchscreen Driver" ); |
356 | MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij" ); |
357 | MODULE_LICENSE("GPL" ); |
358 | |