1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2011 Kionix, Inc.
4 * Written by Chris Hudson <chudson@kionix.com>
5 */
6
7 #include <linux/delay.h>
8 #include <linux/i2c.h>
9 #include <linux/input.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/input/kxtj9.h>
14
15 #define NAME "kxtj9"
16 #define G_MAX 8000
17 /* OUTPUT REGISTERS */
18 #define XOUT_L 0x06
19 #define WHO_AM_I 0x0F
20 /* CONTROL REGISTERS */
21 #define INT_REL 0x1A
22 #define CTRL_REG1 0x1B
23 #define INT_CTRL1 0x1E
24 #define DATA_CTRL 0x21
25 /* CONTROL REGISTER 1 BITS */
26 #define PC1_OFF 0x7F
27 #define PC1_ON (1 << 7)
28 /* Data ready funtion enable bit: set during probe if using irq mode */
29 #define DRDYE (1 << 5)
30 /* DATA CONTROL REGISTER BITS */
31 #define ODR12_5F 0
32 #define ODR25F 1
33 #define ODR50F 2
34 #define ODR100F 3
35 #define ODR200F 4
36 #define ODR400F 5
37 #define ODR800F 6
38 /* INTERRUPT CONTROL REGISTER 1 BITS */
39 /* Set these during probe if using irq mode */
40 #define KXTJ9_IEL (1 << 3)
41 #define KXTJ9_IEA (1 << 4)
42 #define KXTJ9_IEN (1 << 5)
43 /* INPUT_ABS CONSTANTS */
44 #define FUZZ 3
45 #define FLAT 3
46 /* RESUME STATE INDICES */
47 #define RES_DATA_CTRL 0
48 #define RES_CTRL_REG1 1
49 #define RES_INT_CTRL1 2
50 #define RESUME_ENTRIES 3
51
52 /*
53 * The following table lists the maximum appropriate poll interval for each
54 * available output data rate.
55 */
56 static const struct {
57 unsigned int cutoff;
58 u8 mask;
59 } kxtj9_odr_table[] = {
60 { 3, ODR800F },
61 { 5, ODR400F },
62 { 10, ODR200F },
63 { 20, ODR100F },
64 { 40, ODR50F },
65 { 80, ODR25F },
66 { 0, ODR12_5F},
67 };
68
69 struct kxtj9_data {
70 struct i2c_client *client;
71 struct kxtj9_platform_data pdata;
72 struct input_dev *input_dev;
73 unsigned int last_poll_interval;
74 u8 shift;
75 u8 ctrl_reg1;
76 u8 data_ctrl;
77 u8 int_ctrl;
78 };
79
kxtj9_i2c_read(struct kxtj9_data * tj9,u8 addr,u8 * data,int len)80 static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len)
81 {
82 struct i2c_msg msgs[] = {
83 {
84 .addr = tj9->client->addr,
85 .flags = tj9->client->flags,
86 .len = 1,
87 .buf = &addr,
88 },
89 {
90 .addr = tj9->client->addr,
91 .flags = tj9->client->flags | I2C_M_RD,
92 .len = len,
93 .buf = data,
94 },
95 };
96
97 return i2c_transfer(tj9->client->adapter, msgs, 2);
98 }
99
kxtj9_report_acceleration_data(struct kxtj9_data * tj9)100 static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9)
101 {
102 s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */
103 s16 x, y, z;
104 int err;
105
106 err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6);
107 if (err < 0)
108 dev_err(&tj9->client->dev, "accelerometer data read failed\n");
109
110 x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]);
111 y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]);
112 z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]);
113
114 x >>= tj9->shift;
115 y >>= tj9->shift;
116 z >>= tj9->shift;
117
118 input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x);
119 input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y);
120 input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z);
121 input_sync(tj9->input_dev);
122 }
123
kxtj9_isr(int irq,void * dev)124 static irqreturn_t kxtj9_isr(int irq, void *dev)
125 {
126 struct kxtj9_data *tj9 = dev;
127 int err;
128
129 /* data ready is the only possible interrupt type */
130 kxtj9_report_acceleration_data(tj9);
131
132 err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
133 if (err < 0)
134 dev_err(&tj9->client->dev,
135 "error clearing interrupt status: %d\n", err);
136
137 return IRQ_HANDLED;
138 }
139
kxtj9_update_g_range(struct kxtj9_data * tj9,u8 new_g_range)140 static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range)
141 {
142 switch (new_g_range) {
143 case KXTJ9_G_2G:
144 tj9->shift = 4;
145 break;
146 case KXTJ9_G_4G:
147 tj9->shift = 3;
148 break;
149 case KXTJ9_G_8G:
150 tj9->shift = 2;
151 break;
152 default:
153 return -EINVAL;
154 }
155
156 tj9->ctrl_reg1 &= 0xe7;
157 tj9->ctrl_reg1 |= new_g_range;
158
159 return 0;
160 }
161
kxtj9_update_odr(struct kxtj9_data * tj9,unsigned int poll_interval)162 static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval)
163 {
164 int err;
165 int i;
166
167 /* Use the lowest ODR that can support the requested poll interval */
168 for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) {
169 tj9->data_ctrl = kxtj9_odr_table[i].mask;
170 if (poll_interval < kxtj9_odr_table[i].cutoff)
171 break;
172 }
173
174 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
175 if (err < 0)
176 return err;
177
178 err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl);
179 if (err < 0)
180 return err;
181
182 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
183 if (err < 0)
184 return err;
185
186 return 0;
187 }
188
kxtj9_device_power_on(struct kxtj9_data * tj9)189 static int kxtj9_device_power_on(struct kxtj9_data *tj9)
190 {
191 if (tj9->pdata.power_on)
192 return tj9->pdata.power_on();
193
194 return 0;
195 }
196
kxtj9_device_power_off(struct kxtj9_data * tj9)197 static void kxtj9_device_power_off(struct kxtj9_data *tj9)
198 {
199 int err;
200
201 tj9->ctrl_reg1 &= PC1_OFF;
202 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
203 if (err < 0)
204 dev_err(&tj9->client->dev, "soft power off failed\n");
205
206 if (tj9->pdata.power_off)
207 tj9->pdata.power_off();
208 }
209
kxtj9_enable(struct kxtj9_data * tj9)210 static int kxtj9_enable(struct kxtj9_data *tj9)
211 {
212 int err;
213
214 err = kxtj9_device_power_on(tj9);
215 if (err < 0)
216 return err;
217
218 /* ensure that PC1 is cleared before updating control registers */
219 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
220 if (err < 0)
221 return err;
222
223 /* only write INT_CTRL_REG1 if in irq mode */
224 if (tj9->client->irq) {
225 err = i2c_smbus_write_byte_data(tj9->client,
226 INT_CTRL1, tj9->int_ctrl);
227 if (err < 0)
228 return err;
229 }
230
231 err = kxtj9_update_g_range(tj9, tj9->pdata.g_range);
232 if (err < 0)
233 return err;
234
235 /* turn on outputs */
236 tj9->ctrl_reg1 |= PC1_ON;
237 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
238 if (err < 0)
239 return err;
240
241 err = kxtj9_update_odr(tj9, tj9->last_poll_interval);
242 if (err < 0)
243 return err;
244
245 /* clear initial interrupt if in irq mode */
246 if (tj9->client->irq) {
247 err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
248 if (err < 0) {
249 dev_err(&tj9->client->dev,
250 "error clearing interrupt: %d\n", err);
251 goto fail;
252 }
253 }
254
255 return 0;
256
257 fail:
258 kxtj9_device_power_off(tj9);
259 return err;
260 }
261
kxtj9_disable(struct kxtj9_data * tj9)262 static void kxtj9_disable(struct kxtj9_data *tj9)
263 {
264 kxtj9_device_power_off(tj9);
265 }
266
kxtj9_input_open(struct input_dev * input)267 static int kxtj9_input_open(struct input_dev *input)
268 {
269 struct kxtj9_data *tj9 = input_get_drvdata(input);
270
271 return kxtj9_enable(tj9);
272 }
273
kxtj9_input_close(struct input_dev * dev)274 static void kxtj9_input_close(struct input_dev *dev)
275 {
276 struct kxtj9_data *tj9 = input_get_drvdata(dev);
277
278 kxtj9_disable(tj9);
279 }
280
281 /*
282 * When IRQ mode is selected, we need to provide an interface to allow the user
283 * to change the output data rate of the part. For consistency, we are using
284 * the set_poll method, which accepts a poll interval in milliseconds, and then
285 * calls update_odr() while passing this value as an argument. In IRQ mode, the
286 * data outputs will not be read AT the requested poll interval, rather, the
287 * lowest ODR that can support the requested interval. The client application
288 * will be responsible for retrieving data from the input node at the desired
289 * interval.
290 */
291
292 /* Returns currently selected poll interval (in ms) */
kxtj9_get_poll(struct device * dev,struct device_attribute * attr,char * buf)293 static ssize_t kxtj9_get_poll(struct device *dev,
294 struct device_attribute *attr, char *buf)
295 {
296 struct i2c_client *client = to_i2c_client(dev);
297 struct kxtj9_data *tj9 = i2c_get_clientdata(client);
298
299 return sprintf(buf, "%d\n", tj9->last_poll_interval);
300 }
301
302 /* Allow users to select a new poll interval (in ms) */
kxtj9_set_poll(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)303 static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr,
304 const char *buf, size_t count)
305 {
306 struct i2c_client *client = to_i2c_client(dev);
307 struct kxtj9_data *tj9 = i2c_get_clientdata(client);
308 struct input_dev *input_dev = tj9->input_dev;
309 unsigned int interval;
310 int error;
311
312 error = kstrtouint(buf, 10, &interval);
313 if (error < 0)
314 return error;
315
316 /* Lock the device to prevent races with open/close (and itself) */
317 mutex_lock(&input_dev->mutex);
318
319 disable_irq(client->irq);
320
321 /*
322 * Set current interval to the greater of the minimum interval or
323 * the requested interval
324 */
325 tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
326
327 kxtj9_update_odr(tj9, tj9->last_poll_interval);
328
329 enable_irq(client->irq);
330 mutex_unlock(&input_dev->mutex);
331
332 return count;
333 }
334
335 static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
336
337 static struct attribute *kxtj9_attributes[] = {
338 &dev_attr_poll.attr,
339 NULL
340 };
341
342 static struct attribute_group kxtj9_attribute_group = {
343 .attrs = kxtj9_attributes
344 };
345
kxtj9_poll(struct input_dev * input)346 static void kxtj9_poll(struct input_dev *input)
347 {
348 struct kxtj9_data *tj9 = input_get_drvdata(input);
349 unsigned int poll_interval = input_get_poll_interval(input);
350
351 kxtj9_report_acceleration_data(tj9);
352
353 if (poll_interval != tj9->last_poll_interval) {
354 kxtj9_update_odr(tj9, poll_interval);
355 tj9->last_poll_interval = poll_interval;
356 }
357 }
358
kxtj9_platform_exit(void * data)359 static void kxtj9_platform_exit(void *data)
360 {
361 struct kxtj9_data *tj9 = data;
362
363 if (tj9->pdata.exit)
364 tj9->pdata.exit();
365 }
366
kxtj9_verify(struct kxtj9_data * tj9)367 static int kxtj9_verify(struct kxtj9_data *tj9)
368 {
369 int retval;
370
371 retval = kxtj9_device_power_on(tj9);
372 if (retval < 0)
373 return retval;
374
375 retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
376 if (retval < 0) {
377 dev_err(&tj9->client->dev, "read err int source\n");
378 goto out;
379 }
380
381 retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
382
383 out:
384 kxtj9_device_power_off(tj9);
385 return retval;
386 }
387
kxtj9_probe(struct i2c_client * client)388 static int kxtj9_probe(struct i2c_client *client)
389 {
390 const struct kxtj9_platform_data *pdata =
391 dev_get_platdata(&client->dev);
392 struct kxtj9_data *tj9;
393 struct input_dev *input_dev;
394 int err;
395
396 if (!i2c_check_functionality(client->adapter,
397 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
398 dev_err(&client->dev, "client is not i2c capable\n");
399 return -ENXIO;
400 }
401
402 if (!pdata) {
403 dev_err(&client->dev, "platform data is NULL; exiting\n");
404 return -EINVAL;
405 }
406
407 tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
408 if (!tj9) {
409 dev_err(&client->dev,
410 "failed to allocate memory for module data\n");
411 return -ENOMEM;
412 }
413
414 tj9->client = client;
415 tj9->pdata = *pdata;
416
417 if (pdata->init) {
418 err = pdata->init();
419 if (err < 0)
420 return err;
421 }
422
423 err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
424 if (err)
425 return err;
426
427 err = kxtj9_verify(tj9);
428 if (err < 0) {
429 dev_err(&client->dev, "device not recognized\n");
430 return err;
431 }
432
433 i2c_set_clientdata(client, tj9);
434
435 tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
436 tj9->last_poll_interval = tj9->pdata.init_interval;
437
438 input_dev = devm_input_allocate_device(&client->dev);
439 if (!input_dev) {
440 dev_err(&client->dev, "input device allocate failed\n");
441 return -ENOMEM;
442 }
443
444 input_set_drvdata(input_dev, tj9);
445 tj9->input_dev = input_dev;
446
447 input_dev->name = "kxtj9_accel";
448 input_dev->id.bustype = BUS_I2C;
449
450 input_dev->open = kxtj9_input_open;
451 input_dev->close = kxtj9_input_close;
452
453 input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
454 input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
455 input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
456
457 if (client->irq <= 0) {
458 err = input_setup_polling(input_dev, kxtj9_poll);
459 if (err)
460 return err;
461 }
462
463 err = input_register_device(input_dev);
464 if (err) {
465 dev_err(&client->dev,
466 "unable to register input polled device %s: %d\n",
467 input_dev->name, err);
468 return err;
469 }
470
471 if (client->irq) {
472 /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
473 tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
474 tj9->ctrl_reg1 |= DRDYE;
475
476 err = devm_request_threaded_irq(&client->dev, client->irq,
477 NULL, kxtj9_isr,
478 IRQF_TRIGGER_RISING |
479 IRQF_ONESHOT,
480 "kxtj9-irq", tj9);
481 if (err) {
482 dev_err(&client->dev, "request irq failed: %d\n", err);
483 return err;
484 }
485
486 err = devm_device_add_group(&client->dev,
487 &kxtj9_attribute_group);
488 if (err) {
489 dev_err(&client->dev, "sysfs create failed: %d\n", err);
490 return err;
491 }
492 }
493
494 return 0;
495 }
496
kxtj9_suspend(struct device * dev)497 static int kxtj9_suspend(struct device *dev)
498 {
499 struct i2c_client *client = to_i2c_client(dev);
500 struct kxtj9_data *tj9 = i2c_get_clientdata(client);
501 struct input_dev *input_dev = tj9->input_dev;
502
503 mutex_lock(&input_dev->mutex);
504
505 if (input_device_enabled(input_dev))
506 kxtj9_disable(tj9);
507
508 mutex_unlock(&input_dev->mutex);
509 return 0;
510 }
511
kxtj9_resume(struct device * dev)512 static int kxtj9_resume(struct device *dev)
513 {
514 struct i2c_client *client = to_i2c_client(dev);
515 struct kxtj9_data *tj9 = i2c_get_clientdata(client);
516 struct input_dev *input_dev = tj9->input_dev;
517
518 mutex_lock(&input_dev->mutex);
519
520 if (input_device_enabled(input_dev))
521 kxtj9_enable(tj9);
522
523 mutex_unlock(&input_dev->mutex);
524 return 0;
525 }
526
527 static DEFINE_SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
528
529 static const struct i2c_device_id kxtj9_id[] = {
530 { NAME, 0 },
531 { },
532 };
533
534 MODULE_DEVICE_TABLE(i2c, kxtj9_id);
535
536 static struct i2c_driver kxtj9_driver = {
537 .driver = {
538 .name = NAME,
539 .pm = pm_sleep_ptr(&kxtj9_pm_ops),
540 },
541 .probe = kxtj9_probe,
542 .id_table = kxtj9_id,
543 };
544
545 module_i2c_driver(kxtj9_driver);
546
547 MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
548 MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
549 MODULE_LICENSE("GPL");
550