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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Kionix, Inc.
4 * Written by Chris Hudson <[email protected]>
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 function 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 */
56static 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
69struct 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
80static 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
100static 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
124static 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
140static 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
162static 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
189static 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
197static 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
210static 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
257fail:
258 kxtj9_device_power_off(tj9);
259 return err;
260}
261
262static void kxtj9_disable(struct kxtj9_data *tj9)
263{
264 kxtj9_device_power_off(tj9);
265}
266
267static 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
274static 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) */
293static 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) */
303static 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 guard(mutex)(&input_dev->mutex);
318 guard(disable_irq)(&client->irq);
319
320 /*
321 * Set current interval to the greater of the minimum interval or
322 * the requested interval
323 */
324 tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
325
326 kxtj9_update_odr(tj9, tj9->last_poll_interval);
327
328 return count;
329}
330
331static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
332
333static struct attribute *kxtj9_attrs[] = {
334 &dev_attr_poll.attr,
335 NULL
336};
337
338static umode_t kxtj9_attr_is_visible(struct kobject *kobj,
339 struct attribute *attr, int n)
340{
341 struct device *dev = kobj_to_dev(kobj);
342 struct i2c_client *client = to_i2c_client(dev);
343
344 return client->irq ? attr->mode : 0;
345}
346
347static struct attribute_group kxtj9_group = {
348 .attrs = kxtj9_attrs,
349 .is_visible = kxtj9_attr_is_visible,
350};
351__ATTRIBUTE_GROUPS(kxtj9);
352
353static void kxtj9_poll(struct input_dev *input)
354{
355 struct kxtj9_data *tj9 = input_get_drvdata(input);
356 unsigned int poll_interval = input_get_poll_interval(input);
357
358 kxtj9_report_acceleration_data(tj9);
359
360 if (poll_interval != tj9->last_poll_interval) {
361 kxtj9_update_odr(tj9, poll_interval);
362 tj9->last_poll_interval = poll_interval;
363 }
364}
365
366static void kxtj9_platform_exit(void *data)
367{
368 struct kxtj9_data *tj9 = data;
369
370 if (tj9->pdata.exit)
371 tj9->pdata.exit();
372}
373
374static int kxtj9_verify(struct kxtj9_data *tj9)
375{
376 int retval;
377
378 retval = kxtj9_device_power_on(tj9);
379 if (retval < 0)
380 return retval;
381
382 retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
383 if (retval < 0) {
384 dev_err(&tj9->client->dev, "read err int source\n");
385 goto out;
386 }
387
388 retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
389
390out:
391 kxtj9_device_power_off(tj9);
392 return retval;
393}
394
395static int kxtj9_probe(struct i2c_client *client)
396{
397 const struct kxtj9_platform_data *pdata =
398 dev_get_platdata(&client->dev);
399 struct kxtj9_data *tj9;
400 struct input_dev *input_dev;
401 int err;
402
403 if (!i2c_check_functionality(client->adapter,
404 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
405 dev_err(&client->dev, "client is not i2c capable\n");
406 return -ENXIO;
407 }
408
409 if (!pdata) {
410 dev_err(&client->dev, "platform data is NULL; exiting\n");
411 return -EINVAL;
412 }
413
414 tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
415 if (!tj9) {
416 dev_err(&client->dev,
417 "failed to allocate memory for module data\n");
418 return -ENOMEM;
419 }
420
421 tj9->client = client;
422 tj9->pdata = *pdata;
423
424 if (pdata->init) {
425 err = pdata->init();
426 if (err < 0)
427 return err;
428 }
429
430 err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
431 if (err)
432 return err;
433
434 err = kxtj9_verify(tj9);
435 if (err < 0) {
436 dev_err(&client->dev, "device not recognized\n");
437 return err;
438 }
439
440 i2c_set_clientdata(client, tj9);
441
442 tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
443 tj9->last_poll_interval = tj9->pdata.init_interval;
444
445 input_dev = devm_input_allocate_device(&client->dev);
446 if (!input_dev) {
447 dev_err(&client->dev, "input device allocate failed\n");
448 return -ENOMEM;
449 }
450
451 input_set_drvdata(input_dev, tj9);
452 tj9->input_dev = input_dev;
453
454 input_dev->name = "kxtj9_accel";
455 input_dev->id.bustype = BUS_I2C;
456
457 input_dev->open = kxtj9_input_open;
458 input_dev->close = kxtj9_input_close;
459
460 input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
461 input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
462 input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
463
464 if (client->irq <= 0) {
465 err = input_setup_polling(input_dev, kxtj9_poll);
466 if (err)
467 return err;
468 }
469
470 err = input_register_device(input_dev);
471 if (err) {
472 dev_err(&client->dev,
473 "unable to register input polled device %s: %d\n",
474 input_dev->name, err);
475 return err;
476 }
477
478 if (client->irq) {
479 /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
480 tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
481 tj9->ctrl_reg1 |= DRDYE;
482
483 err = devm_request_threaded_irq(&client->dev, client->irq,
484 NULL, kxtj9_isr,
485 IRQF_TRIGGER_RISING |
486 IRQF_ONESHOT,
487 "kxtj9-irq", tj9);
488 if (err) {
489 dev_err(&client->dev, "request irq failed: %d\n", err);
490 return err;
491 }
492 }
493
494 return 0;
495}
496
497static 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 guard(mutex)(&input_dev->mutex);
504
505 if (input_device_enabled(input_dev))
506 kxtj9_disable(tj9);
507
508 return 0;
509}
510
511static int kxtj9_resume(struct device *dev)
512{
513 struct i2c_client *client = to_i2c_client(dev);
514 struct kxtj9_data *tj9 = i2c_get_clientdata(client);
515 struct input_dev *input_dev = tj9->input_dev;
516
517 guard(mutex)(&input_dev->mutex);
518
519 if (input_device_enabled(input_dev))
520 kxtj9_enable(tj9);
521
522 return 0;
523}
524
525static DEFINE_SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
526
527static const struct i2c_device_id kxtj9_id[] = {
528 { .name = NAME },
529 { }
530};
531
532MODULE_DEVICE_TABLE(i2c, kxtj9_id);
533
534static struct i2c_driver kxtj9_driver = {
535 .driver = {
536 .name = NAME,
537 .dev_groups = kxtj9_groups,
538 .pm = pm_sleep_ptr(&kxtj9_pm_ops),
539 },
540 .probe = kxtj9_probe,
541 .id_table = kxtj9_id,
542};
543
544module_i2c_driver(kxtj9_driver);
545
546MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
547MODULE_AUTHOR("Chris Hudson <[email protected]>");
548MODULE_LICENSE("GPL");