1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for Cypress CY8CTMA140 (TMA140) touchscreen
* (C) 2020 Linus Walleij <linus.walleij@linaro.org>
* (C) 2007 Cypress
* (C) 2007 Google, Inc.
*
* Inspired by the tma140_skomer.c driver in the Samsung GT-S7710 code
* drop. The GT-S7710 is codenamed "Skomer", the code also indicates
* that the same touchscreen was used in a product called "Lucas".
*
* The code drop for GT-S7710 also contains a firmware downloader and
* 15 (!) versions of the firmware drop from Cypress. But here we assume
* the firmware got downloaded to the touchscreen flash successfully and
* just use it to read the fingers. The shipped vendor driver does the
* same.
*/
#include <linux/unaligned.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/input/touchscreen.h>
#include <linux/input/mt.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/i2c.h>
#include <linux/regulator/consumer.h>
#include <linux/delay.h>
#define CY8CTMA140_NAME "cy8ctma140"
#define CY8CTMA140_MAX_FINGERS 4
#define CY8CTMA140_GET_FINGERS 0x00
#define CY8CTMA140_GET_FW_INFO 0x19
/* This message also fits some bytes for touchkeys, if used */
#define CY8CTMA140_PACKET_SIZE 31
#define CY8CTMA140_INVALID_BUFFER_BIT 5
struct cy8ctma140 {
struct input_dev *input;
struct touchscreen_properties props;
struct device *dev;
struct i2c_client *client;
struct regulator_bulk_data regulators[2];
u8 prev_fingers;
u8 prev_f1id;
u8 prev_f2id;
};
static void cy8ctma140_report(struct cy8ctma140 *ts, u8 *data, int n_fingers)
{
static const u8 contact_offsets[] = { 0x03, 0x09, 0x10, 0x16 };
u8 *buf;
u16 x, y;
u8 w;
u8 id;
int slot;
int i;
for (i = 0; i < n_fingers; i++) {
buf = &data[contact_offsets[i]];
/*
* Odd contacts have contact ID in the lower nibble of
* the preceding byte, whereas even contacts have it in
* the upper nibble of the following byte.
*/
id = i % 2 ? buf[-1] & 0x0f : buf[5] >> 4;
slot = input_mt_get_slot_by_key(ts->input, id);
if (slot < 0)
continue;
x = get_unaligned_be16(buf);
y = get_unaligned_be16(buf + 2);
w = buf[4];
dev_dbg(ts->dev, "finger %d: ID %02x (%d, %d) w: %d\n",
slot, id, x, y, w);
input_mt_slot(ts->input, slot);
input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
touchscreen_report_pos(ts->input, &ts->props, x, y, true);
input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, w);
}
input_mt_sync_frame(ts->input);
input_sync(ts->input);
}
static irqreturn_t cy8ctma140_irq_thread(int irq, void *d)
{
struct cy8ctma140 *ts = d;
u8 cmdbuf[] = { CY8CTMA140_GET_FINGERS };
u8 buf[CY8CTMA140_PACKET_SIZE];
struct i2c_msg msg[] = {
{
.addr = ts->client->addr,
.flags = 0,
.len = sizeof(cmdbuf),
.buf = cmdbuf,
}, {
.addr = ts->client->addr,
.flags = I2C_M_RD,
.len = sizeof(buf),
.buf = buf,
},
};
u8 n_fingers;
int ret;
ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
if (ret != ARRAY_SIZE(msg)) {
if (ret < 0)
dev_err(ts->dev, "error reading message: %d\n", ret);
else
dev_err(ts->dev, "wrong number of messages\n");
goto out;
}
if (buf[1] & BIT(CY8CTMA140_INVALID_BUFFER_BIT)) {
dev_dbg(ts->dev, "invalid event\n");
goto out;
}
n_fingers = buf[2] & 0x0f;
if (n_fingers > CY8CTMA140_MAX_FINGERS) {
dev_err(ts->dev, "unexpected number of fingers: %d\n",
n_fingers);
goto out;
}
cy8ctma140_report(ts, buf, n_fingers);
out:
return IRQ_HANDLED;
}
static int cy8ctma140_init(struct cy8ctma140 *ts)
{
u8 addr[1];
u8 buf[5];
int ret;
addr[0] = CY8CTMA140_GET_FW_INFO;
ret = i2c_master_send(ts->client, addr, 1);
if (ret < 0) {
dev_err(ts->dev, "error sending FW info message\n");
return ret;
}
ret = i2c_master_recv(ts->client, buf, 5);
if (ret < 0) {
dev_err(ts->dev, "error receiving FW info message\n");
return ret;
}
if (ret != 5) {
dev_err(ts->dev, "got only %d bytes\n", ret);
return -EIO;
}
dev_dbg(ts->dev, "vendor %c%c, HW ID %.2d, FW ver %.4d\n",
buf[0], buf[1], buf[3], buf[4]);
return 0;
}
static int cy8ctma140_power_up(struct cy8ctma140 *ts)
{
int error;
error = regulator_bulk_enable(ARRAY_SIZE(ts->regulators),
ts->regulators);
if (error) {
dev_err(ts->dev, "failed to enable regulators\n");
return error;
}
msleep(250);
return 0;
}
static void cy8ctma140_power_down(struct cy8ctma140 *ts)
{
regulator_bulk_disable(ARRAY_SIZE(ts->regulators),
ts->regulators);
}
/* Called from the registered devm action */
static void cy8ctma140_power_off_action(void *d)
{
struct cy8ctma140 *ts = d;
cy8ctma140_power_down(ts);
}
static int cy8ctma140_probe(struct i2c_client *client)
{
struct cy8ctma140 *ts;
struct input_dev *input;
struct device *dev = &client->dev;
int error;
ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
if (!ts)
return -ENOMEM;
input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
ts->dev = dev;
ts->client = client;
ts->input = input;
input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
/* One byte for width 0..255 so this is the limit */
input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
/*
* This sets up event max/min capabilities and fuzz.
* Some DT properties are compulsory so we do not need
* to provide defaults for X/Y max or pressure max.
*
* We just initialize a very simple MT touchscreen here,
* some devices use the capability of this touchscreen to
* provide touchkeys, and in that case this needs to be
* extended to handle touchkey input.
*
* The firmware takes care of finger tracking and dropping
* invalid ranges.
*/
touchscreen_parse_properties(input, true, &ts->props);
input_abs_set_fuzz(input, ABS_MT_POSITION_X, 0);
input_abs_set_fuzz(input, ABS_MT_POSITION_Y, 0);
error = input_mt_init_slots(input, CY8CTMA140_MAX_FINGERS,
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
if (error)
return error;
input->name = CY8CTMA140_NAME;
input->id.bustype = BUS_I2C;
input_set_drvdata(input, ts);
/*
* VCPIN is the analog voltage supply
* VDD is the digital voltage supply
* since the voltage range of VDD overlaps that of VCPIN,
* many designs to just supply both with a single voltage
* source of ~3.3 V.
*/
ts->regulators[0].supply = "vcpin";
ts->regulators[1].supply = "vdd";
error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->regulators),
ts->regulators);
if (error)
return dev_err_probe(dev, error, "Failed to get regulators\n");
error = cy8ctma140_power_up(ts);
if (error)
return error;
error = devm_add_action_or_reset(dev, cy8ctma140_power_off_action, ts);
if (error) {
dev_err(dev, "failed to install power off handler\n");
return error;
}
error = devm_request_threaded_irq(dev, client->irq,
NULL, cy8ctma140_irq_thread,
IRQF_ONESHOT, CY8CTMA140_NAME, ts);
if (error) {
dev_err(dev, "irq %d busy? error %d\n", client->irq, error);
return error;
}
error = cy8ctma140_init(ts);
if (error)
return error;
error = input_register_device(input);
if (error)
return error;
i2c_set_clientdata(client, ts);
return 0;
}
static int cy8ctma140_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct cy8ctma140 *ts = i2c_get_clientdata(client);
if (!device_may_wakeup(&client->dev))
cy8ctma140_power_down(ts);
return 0;
}
static int cy8ctma140_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct cy8ctma140 *ts = i2c_get_clientdata(client);
int error;
if (!device_may_wakeup(&client->dev)) {
error = cy8ctma140_power_up(ts);
if (error)
return error;
}
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(cy8ctma140_pm,
cy8ctma140_suspend, cy8ctma140_resume);
static const struct i2c_device_id cy8ctma140_idtable[] = {
{ CY8CTMA140_NAME },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, cy8ctma140_idtable);
static const struct of_device_id cy8ctma140_of_match[] = {
{ .compatible = "cypress,cy8ctma140", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, cy8ctma140_of_match);
static struct i2c_driver cy8ctma140_driver = {
.driver = {
.name = CY8CTMA140_NAME,
.pm = pm_sleep_ptr(&cy8ctma140_pm),
.of_match_table = cy8ctma140_of_match,
},
.id_table = cy8ctma140_idtable,
.probe = cy8ctma140_probe,
};
module_i2c_driver(cy8ctma140_driver);
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("CY8CTMA140 TouchScreen Driver");
MODULE_LICENSE("GPL v2");
|