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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Input driver for Microchip CAP11xx based capacitive touch sensors
4 *
5 * (c) 2014 Daniel Mack <linux@zonque.org>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/interrupt.h>
11#include <linux/input.h>
12#include <linux/leds.h>
13#include <linux/of.h>
14#include <linux/regmap.h>
15#include <linux/i2c.h>
16#include <linux/gpio/consumer.h>
17#include <linux/bitfield.h>
18
19#define CAP11XX_REG_MAIN_CONTROL 0x00
20#define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6)
21#define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0)
22#define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4)
23#define CAP11XX_REG_GENERAL_STATUS 0x02
24#define CAP11XX_REG_SENSOR_INPUT 0x03
25#define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a
26#define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X))
27#define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f
28#define CAP11XX_REG_SENSITIVITY_CONTROL_DELTA_SENSE_MASK 0x70
29#define CAP11XX_REG_CONFIG 0x20
30#define CAP11XX_REG_SENSOR_ENABLE 0x21
31#define CAP11XX_REG_SENSOR_CONFIG 0x22
32#define CAP11XX_REG_SENSOR_CONFIG2 0x23
33#define CAP11XX_REG_SAMPLING_CONFIG 0x24
34#define CAP11XX_REG_CALIBRATION 0x26
35#define CAP11XX_REG_INT_ENABLE 0x27
36#define CAP11XX_REG_REPEAT_RATE 0x28
37#define CAP11XX_REG_SIGNAL_GUARD_ENABLE 0x29
38#define CAP11XX_REG_MT_CONFIG 0x2a
39#define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b
40#define CAP11XX_REG_MT_PATTERN 0x2d
41#define CAP11XX_REG_RECALIB_CONFIG 0x2f
42#define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X))
43#define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38
44#define CAP11XX_REG_STANDBY_CHANNEL 0x40
45#define CAP11XX_REG_STANDBY_CONFIG 0x41
46#define CAP11XX_REG_STANDBY_SENSITIVITY 0x42
47#define CAP11XX_REG_STANDBY_THRESH 0x43
48#define CAP11XX_REG_CONFIG2 0x44
49#define CAP11XX_REG_CONFIG2_ALT_POL BIT(6)
50#define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X))
51#define CAP11XX_REG_LED_POLARITY 0x73
52#define CAP11XX_REG_LED_OUTPUT_CONTROL 0x74
53#define CAP11XX_REG_CALIB_SENSITIVITY_CONFIG 0x80
54#define CAP11XX_REG_CALIB_SENSITIVITY_CONFIG2 0x81
55
56#define CAP11XX_REG_LED_DUTY_CYCLE_1 0x90
57#define CAP11XX_REG_LED_DUTY_CYCLE_2 0x91
58#define CAP11XX_REG_LED_DUTY_CYCLE_3 0x92
59#define CAP11XX_REG_LED_DUTY_CYCLE_4 0x93
60
61#define CAP11XX_REG_LED_DUTY_MIN_MASK (0x0f)
62#define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT (0)
63#define CAP11XX_REG_LED_DUTY_MAX_MASK (0xf0)
64#define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT (4)
65#define CAP11XX_REG_LED_DUTY_MAX_VALUE (15)
66
67#define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X))
68#define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9
69#define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba
70#define CAP11XX_REG_PRODUCT_ID 0xfd
71#define CAP11XX_REG_MANUFACTURER_ID 0xfe
72#define CAP11XX_REG_REVISION 0xff
73
74#define CAP11XX_MANUFACTURER_ID 0x5d
75
76#ifdef CONFIG_LEDS_CLASS
77struct cap11xx_led {
78 struct cap11xx_priv *priv;
79 struct led_classdev cdev;
80 u32 reg;
81};
82#endif
83
84struct cap11xx_priv {
85 struct regmap *regmap;
86 struct device *dev;
87 struct input_dev *idev;
88 const struct cap11xx_hw_model *model;
89 u8 id;
90
91 struct cap11xx_led *leds;
92 int num_leds;
93
94 /* config */
95 u8 analog_gain;
96 u8 sensitivity_delta_sense;
97 u8 signal_guard_inputs_mask;
98 u32 thresholds[8];
99 u32 calib_sensitivities[8];
100 u32 keycodes[];
101};
102
103struct cap11xx_hw_model {
104 u8 product_id;
105 unsigned int num_channels;
106 unsigned int num_leds;
107 bool no_gain;
108};
109
110enum {
111 CAP1106,
112 CAP1126,
113 CAP1188,
114 CAP1203,
115 CAP1206,
116 CAP1293,
117 CAP1298
118};
119
120static const struct cap11xx_hw_model cap11xx_devices[] = {
121 [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0, .no_gain = false },
122 [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2, .no_gain = false },
123 [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8, .no_gain = false },
124 [CAP1203] = { .product_id = 0x6d, .num_channels = 3, .num_leds = 0, .no_gain = true },
125 [CAP1206] = { .product_id = 0x67, .num_channels = 6, .num_leds = 0, .no_gain = true },
126 [CAP1293] = { .product_id = 0x6f, .num_channels = 3, .num_leds = 0, .no_gain = false },
127 [CAP1298] = { .product_id = 0x71, .num_channels = 8, .num_leds = 0, .no_gain = false },
128};
129
130static const struct reg_default cap11xx_reg_defaults[] = {
131 { CAP11XX_REG_MAIN_CONTROL, 0x00 },
132 { CAP11XX_REG_GENERAL_STATUS, 0x00 },
133 { CAP11XX_REG_SENSOR_INPUT, 0x00 },
134 { CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 },
135 { CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f },
136 { CAP11XX_REG_CONFIG, 0x20 },
137 { CAP11XX_REG_SENSOR_ENABLE, 0x3f },
138 { CAP11XX_REG_SENSOR_CONFIG, 0xa4 },
139 { CAP11XX_REG_SENSOR_CONFIG2, 0x07 },
140 { CAP11XX_REG_SAMPLING_CONFIG, 0x39 },
141 { CAP11XX_REG_CALIBRATION, 0x00 },
142 { CAP11XX_REG_INT_ENABLE, 0x3f },
143 { CAP11XX_REG_REPEAT_RATE, 0x3f },
144 { CAP11XX_REG_MT_CONFIG, 0x80 },
145 { CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 },
146 { CAP11XX_REG_MT_PATTERN, 0x3f },
147 { CAP11XX_REG_RECALIB_CONFIG, 0x8a },
148 { CAP11XX_REG_SENSOR_THRESH(0), 0x40 },
149 { CAP11XX_REG_SENSOR_THRESH(1), 0x40 },
150 { CAP11XX_REG_SENSOR_THRESH(2), 0x40 },
151 { CAP11XX_REG_SENSOR_THRESH(3), 0x40 },
152 { CAP11XX_REG_SENSOR_THRESH(4), 0x40 },
153 { CAP11XX_REG_SENSOR_THRESH(5), 0x40 },
154 { CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 },
155 { CAP11XX_REG_STANDBY_CHANNEL, 0x00 },
156 { CAP11XX_REG_STANDBY_CONFIG, 0x39 },
157 { CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 },
158 { CAP11XX_REG_STANDBY_THRESH, 0x40 },
159 { CAP11XX_REG_CONFIG2, 0x40 },
160 { CAP11XX_REG_LED_POLARITY, 0x00 },
161 { CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 },
162 { CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 },
163};
164
165static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
166{
167 switch (reg) {
168 case CAP11XX_REG_MAIN_CONTROL:
169 case CAP11XX_REG_SENSOR_INPUT:
170 case CAP11XX_REG_SENOR_DELTA(0):
171 case CAP11XX_REG_SENOR_DELTA(1):
172 case CAP11XX_REG_SENOR_DELTA(2):
173 case CAP11XX_REG_SENOR_DELTA(3):
174 case CAP11XX_REG_SENOR_DELTA(4):
175 case CAP11XX_REG_SENOR_DELTA(5):
176 return true;
177 }
178
179 return false;
180}
181
182static const struct regmap_config cap11xx_regmap_config = {
183 .reg_bits = 8,
184 .val_bits = 8,
185
186 .max_register = CAP11XX_REG_REVISION,
187 .reg_defaults = cap11xx_reg_defaults,
188
189 .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
190 .cache_type = REGCACHE_MAPLE,
191 .volatile_reg = cap11xx_volatile_reg,
192};
193
194static int cap11xx_write_calib_sens_config_1(struct cap11xx_priv *priv)
195{
196 return regmap_write(priv->regmap,
197 CAP11XX_REG_CALIB_SENSITIVITY_CONFIG,
198 (priv->calib_sensitivities[3] << 6) |
199 (priv->calib_sensitivities[2] << 4) |
200 (priv->calib_sensitivities[1] << 2) |
201 priv->calib_sensitivities[0]);
202}
203
204static int cap11xx_write_calib_sens_config_2(struct cap11xx_priv *priv)
205{
206 return regmap_write(priv->regmap,
207 CAP11XX_REG_CALIB_SENSITIVITY_CONFIG2,
208 (priv->calib_sensitivities[7] << 6) |
209 (priv->calib_sensitivities[6] << 4) |
210 (priv->calib_sensitivities[5] << 2) |
211 priv->calib_sensitivities[4]);
212}
213
214static int cap11xx_init_keys(struct cap11xx_priv *priv)
215{
216 struct device_node *node = priv->dev->of_node;
217 struct device *dev = priv->dev;
218 int i, error;
219 u32 u32_val;
220
221 if (!node) {
222 dev_err(dev, "Corresponding DT entry is not available\n");
223 return -ENODEV;
224 }
225
226 if (!of_property_read_u32(node, "microchip,sensor-gain", &u32_val)) {
227 if (priv->model->no_gain) {
228 dev_warn(dev,
229 "This model doesn't support 'sensor-gain'\n");
230 } else if (is_power_of_2(u32_val) && u32_val <= 8) {
231 priv->analog_gain = (u8)ilog2(u32_val);
232
233 error = regmap_update_bits(priv->regmap,
234 CAP11XX_REG_MAIN_CONTROL,
235 CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
236 priv->analog_gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
237 if (error)
238 return error;
239 } else {
240 dev_err(dev, "Invalid sensor-gain value %u\n", u32_val);
241 return -EINVAL;
242 }
243 }
244
245 if (of_property_read_bool(node, "microchip,irq-active-high")) {
246 if (priv->id == CAP1106 ||
247 priv->id == CAP1126 ||
248 priv->id == CAP1188) {
249 error = regmap_update_bits(priv->regmap,
250 CAP11XX_REG_CONFIG2,
251 CAP11XX_REG_CONFIG2_ALT_POL,
252 0);
253 if (error)
254 return error;
255 } else {
256 dev_warn(dev,
257 "This model doesn't support 'irq-active-high'\n");
258 }
259 }
260
261 if (!of_property_read_u32(node, "microchip,sensitivity-delta-sense", &u32_val)) {
262 if (!is_power_of_2(u32_val) || u32_val > 128) {
263 dev_err(dev, "Invalid sensitivity-delta-sense value %u\n", u32_val);
264 return -EINVAL;
265 }
266
267 priv->sensitivity_delta_sense = (u8)ilog2(u32_val);
268 u32_val = ~(FIELD_PREP(CAP11XX_REG_SENSITIVITY_CONTROL_DELTA_SENSE_MASK,
269 priv->sensitivity_delta_sense));
270
271 error = regmap_update_bits(priv->regmap,
272 CAP11XX_REG_SENSITIVITY_CONTROL,
273 CAP11XX_REG_SENSITIVITY_CONTROL_DELTA_SENSE_MASK,
274 u32_val);
275 if (error)
276 return error;
277 }
278
279 if (!of_property_read_u32_array(node, "microchip,input-threshold",
280 priv->thresholds, priv->model->num_channels)) {
281 for (i = 0; i < priv->model->num_channels; i++) {
282 if (priv->thresholds[i] > 127) {
283 dev_err(dev, "Invalid input-threshold value %u\n",
284 priv->thresholds[i]);
285 return -EINVAL;
286 }
287
288 error = regmap_write(priv->regmap,
289 CAP11XX_REG_SENSOR_THRESH(i),
290 priv->thresholds[i]);
291 if (error)
292 return error;
293 }
294 }
295
296 if (!of_property_read_u32_array(node, "microchip,calib-sensitivity",
297 priv->calib_sensitivities,
298 priv->model->num_channels)) {
299 if (priv->id == CAP1293 || priv->id == CAP1298) {
300 for (i = 0; i < priv->model->num_channels; i++) {
301 if (!is_power_of_2(priv->calib_sensitivities[i]) ||
302 priv->calib_sensitivities[i] > 4) {
303 dev_err(dev, "Invalid calib-sensitivity value %u\n",
304 priv->calib_sensitivities[i]);
305 return -EINVAL;
306 }
307 priv->calib_sensitivities[i] = ilog2(priv->calib_sensitivities[i]);
308 }
309
310 error = cap11xx_write_calib_sens_config_1(priv);
311 if (error)
312 return error;
313
314 if (priv->id == CAP1298) {
315 error = cap11xx_write_calib_sens_config_2(priv);
316 if (error)
317 return error;
318 }
319 } else {
320 dev_warn(dev,
321 "This model doesn't support 'calib-sensitivity'\n");
322 }
323 }
324
325 for (i = 0; i < priv->model->num_channels; i++) {
326 if (!of_property_read_u32_index(node, "microchip,signal-guard",
327 i, &u32_val)) {
328 if (u32_val > 1)
329 return -EINVAL;
330 if (u32_val)
331 priv->signal_guard_inputs_mask |= 0x01 << i;
332 }
333 }
334
335 if (priv->signal_guard_inputs_mask) {
336 if (priv->id == CAP1293 || priv->id == CAP1298) {
337 error = regmap_write(priv->regmap,
338 CAP11XX_REG_SIGNAL_GUARD_ENABLE,
339 priv->signal_guard_inputs_mask);
340 if (error)
341 return error;
342 } else {
343 dev_warn(dev,
344 "This model doesn't support 'signal-guard'\n");
345 }
346 }
347
348 /* Provide some useful defaults */
349 for (i = 0; i < priv->model->num_channels; i++)
350 priv->keycodes[i] = KEY_A + i;
351
352 of_property_read_u32_array(node, "linux,keycodes",
353 priv->keycodes, priv->model->num_channels);
354
355 /* Disable autorepeat. The Linux input system has its own handling. */
356 error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
357 if (error)
358 return error;
359
360 return 0;
361}
362
363static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
364{
365 struct cap11xx_priv *priv = data;
366 unsigned int status;
367 int ret, i;
368
369 /*
370 * Deassert interrupt. This needs to be done before reading the status
371 * registers, which will not carry valid values otherwise.
372 */
373 ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
374 if (ret < 0)
375 goto out;
376
377 ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
378 if (ret < 0)
379 goto out;
380
381 for (i = 0; i < priv->idev->keycodemax; i++)
382 input_report_key(priv->idev, priv->keycodes[i],
383 status & (1 << i));
384
385 input_sync(priv->idev);
386
387out:
388 return IRQ_HANDLED;
389}
390
391static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
392{
393 /*
394 * DLSEEP mode will turn off all LEDS, prevent this
395 */
396 if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds)
397 return 0;
398
399 return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
400 CAP11XX_REG_MAIN_CONTROL_DLSEEP,
401 sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
402}
403
404static int cap11xx_input_open(struct input_dev *idev)
405{
406 struct cap11xx_priv *priv = input_get_drvdata(idev);
407
408 return cap11xx_set_sleep(priv, false);
409}
410
411static void cap11xx_input_close(struct input_dev *idev)
412{
413 struct cap11xx_priv *priv = input_get_drvdata(idev);
414
415 cap11xx_set_sleep(priv, true);
416}
417
418#ifdef CONFIG_LEDS_CLASS
419static int cap11xx_led_set(struct led_classdev *cdev,
420 enum led_brightness value)
421{
422 struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
423 struct cap11xx_priv *priv = led->priv;
424
425 /*
426 * All LEDs share the same duty cycle as this is a HW
427 * limitation. Brightness levels per LED are either
428 * 0 (OFF) and 1 (ON).
429 */
430 return regmap_update_bits(priv->regmap,
431 CAP11XX_REG_LED_OUTPUT_CONTROL,
432 BIT(led->reg),
433 value ? BIT(led->reg) : 0);
434}
435
436static int cap11xx_init_leds(struct device *dev,
437 struct cap11xx_priv *priv, int num_leds)
438{
439 struct device_node *node = dev->of_node, *child;
440 struct cap11xx_led *led;
441 int cnt = of_get_child_count(node);
442 int error;
443
444 if (!num_leds || !cnt)
445 return 0;
446
447 if (cnt > num_leds)
448 return -EINVAL;
449
450 led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL);
451 if (!led)
452 return -ENOMEM;
453
454 priv->leds = led;
455
456 error = regmap_update_bits(priv->regmap,
457 CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
458 if (error)
459 return error;
460
461 error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4,
462 CAP11XX_REG_LED_DUTY_MAX_MASK,
463 CAP11XX_REG_LED_DUTY_MAX_VALUE <<
464 CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT);
465 if (error)
466 return error;
467
468 for_each_child_of_node(node, child) {
469 u32 reg;
470
471 led->cdev.name =
472 of_get_property(child, "label", NULL) ? : child->name;
473 led->cdev.default_trigger =
474 of_get_property(child, "linux,default-trigger", NULL);
475 led->cdev.flags = 0;
476 led->cdev.brightness_set_blocking = cap11xx_led_set;
477 led->cdev.max_brightness = 1;
478 led->cdev.brightness = LED_OFF;
479
480 error = of_property_read_u32(child, "reg", ®);
481 if (error != 0 || reg >= num_leds) {
482 of_node_put(child);
483 return -EINVAL;
484 }
485
486 led->reg = reg;
487 led->priv = priv;
488
489 error = devm_led_classdev_register(dev, &led->cdev);
490 if (error) {
491 of_node_put(child);
492 return error;
493 }
494
495 priv->num_leds++;
496 led++;
497 }
498
499 return 0;
500}
501#else
502static int cap11xx_init_leds(struct device *dev,
503 struct cap11xx_priv *priv, int num_leds)
504{
505 return 0;
506}
507#endif
508
509static int cap11xx_i2c_probe(struct i2c_client *i2c_client)
510{
511 const struct i2c_device_id *id = i2c_client_get_device_id(i2c_client);
512 struct device *dev = &i2c_client->dev;
513 struct cap11xx_priv *priv;
514 const struct cap11xx_hw_model *cap;
515 int i, error;
516 unsigned int val, rev;
517
518 if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
519 dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
520 return -EINVAL;
521 }
522
523 cap = &cap11xx_devices[id->driver_data];
524 if (!cap || !cap->num_channels) {
525 dev_err(dev, "Invalid device configuration\n");
526 return -EINVAL;
527 }
528
529 priv = devm_kzalloc(dev,
530 struct_size(priv, keycodes, cap->num_channels),
531 GFP_KERNEL);
532 if (!priv)
533 return -ENOMEM;
534
535 priv->dev = dev;
536
537 priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
538 if (IS_ERR(priv->regmap))
539 return PTR_ERR(priv->regmap);
540
541 error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
542 if (error)
543 return error;
544
545 if (val != cap->product_id) {
546 dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
547 val, cap->product_id);
548 return -ENXIO;
549 }
550
551 error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
552 if (error)
553 return error;
554
555 if (val != CAP11XX_MANUFACTURER_ID) {
556 dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
557 val, CAP11XX_MANUFACTURER_ID);
558 return -ENXIO;
559 }
560
561 error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
562 if (error < 0)
563 return error;
564
565 dev_info(dev, "CAP11XX detected, model %s, revision 0x%02x\n",
566 id->name, rev);
567
568 priv->model = cap;
569 priv->id = id->driver_data;
570
571 dev_info(dev, "CAP11XX device detected, model %s, revision 0x%02x\n",
572 id->name, rev);
573
574 error = cap11xx_init_keys(priv);
575 if (error)
576 return error;
577
578 priv->idev = devm_input_allocate_device(dev);
579 if (!priv->idev)
580 return -ENOMEM;
581
582 priv->idev->name = "CAP11XX capacitive touch sensor";
583 priv->idev->id.bustype = BUS_I2C;
584 priv->idev->evbit[0] = BIT_MASK(EV_KEY);
585
586 if (of_property_read_bool(dev->of_node, "autorepeat"))
587 __set_bit(EV_REP, priv->idev->evbit);
588
589 for (i = 0; i < cap->num_channels; i++)
590 __set_bit(priv->keycodes[i], priv->idev->keybit);
591
592 __clear_bit(KEY_RESERVED, priv->idev->keybit);
593
594 priv->idev->keycode = priv->keycodes;
595 priv->idev->keycodesize = sizeof(priv->keycodes[0]);
596 priv->idev->keycodemax = cap->num_channels;
597
598 priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
599 priv->idev->id.product = cap->product_id;
600 priv->idev->id.version = rev;
601
602 priv->idev->open = cap11xx_input_open;
603 priv->idev->close = cap11xx_input_close;
604
605 error = cap11xx_init_leds(dev, priv, cap->num_leds);
606 if (error)
607 return error;
608
609 input_set_drvdata(priv->idev, priv);
610
611 /*
612 * Put the device in deep sleep mode for now.
613 * ->open() will bring it back once the it is actually needed.
614 */
615 cap11xx_set_sleep(priv, true);
616
617 error = input_register_device(priv->idev);
618 if (error)
619 return error;
620
621 error = devm_request_threaded_irq(dev, i2c_client->irq,
622 NULL, cap11xx_thread_func,
623 IRQF_ONESHOT, dev_name(dev), priv);
624 if (error)
625 return error;
626
627 return 0;
628}
629
630static const struct of_device_id cap11xx_dt_ids[] = {
631 { .compatible = "microchip,cap1106", },
632 { .compatible = "microchip,cap1126", },
633 { .compatible = "microchip,cap1188", },
634 { .compatible = "microchip,cap1203", },
635 { .compatible = "microchip,cap1206", },
636 { .compatible = "microchip,cap1293", },
637 { .compatible = "microchip,cap1298", },
638 {}
639};
640MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
641
642static const struct i2c_device_id cap11xx_i2c_ids[] = {
643 { "cap1106", CAP1106 },
644 { "cap1126", CAP1126 },
645 { "cap1188", CAP1188 },
646 { "cap1203", CAP1203 },
647 { "cap1206", CAP1206 },
648 { "cap1293", CAP1293 },
649 { "cap1298", CAP1298 },
650 {}
651};
652MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
653
654static struct i2c_driver cap11xx_i2c_driver = {
655 .driver = {
656 .name = "cap11xx",
657 .of_match_table = cap11xx_dt_ids,
658 },
659 .id_table = cap11xx_i2c_ids,
660 .probe = cap11xx_i2c_probe,
661};
662
663module_i2c_driver(cap11xx_i2c_driver);
664
665MODULE_DESCRIPTION("Microchip CAP11XX driver");
666MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
667MODULE_LICENSE("GPL v2");
1/*
2 * Input driver for Microchip CAP11xx based capacitive touch sensors
3 *
4 * (c) 2014 Daniel Mack <linux@zonque.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/interrupt.h>
14#include <linux/input.h>
15#include <linux/leds.h>
16#include <linux/of_irq.h>
17#include <linux/regmap.h>
18#include <linux/i2c.h>
19#include <linux/gpio/consumer.h>
20
21#define CAP11XX_REG_MAIN_CONTROL 0x00
22#define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6)
23#define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0)
24#define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4)
25#define CAP11XX_REG_GENERAL_STATUS 0x02
26#define CAP11XX_REG_SENSOR_INPUT 0x03
27#define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a
28#define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X))
29#define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f
30#define CAP11XX_REG_CONFIG 0x20
31#define CAP11XX_REG_SENSOR_ENABLE 0x21
32#define CAP11XX_REG_SENSOR_CONFIG 0x22
33#define CAP11XX_REG_SENSOR_CONFIG2 0x23
34#define CAP11XX_REG_SAMPLING_CONFIG 0x24
35#define CAP11XX_REG_CALIBRATION 0x26
36#define CAP11XX_REG_INT_ENABLE 0x27
37#define CAP11XX_REG_REPEAT_RATE 0x28
38#define CAP11XX_REG_MT_CONFIG 0x2a
39#define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b
40#define CAP11XX_REG_MT_PATTERN 0x2d
41#define CAP11XX_REG_RECALIB_CONFIG 0x2f
42#define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X))
43#define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38
44#define CAP11XX_REG_STANDBY_CHANNEL 0x40
45#define CAP11XX_REG_STANDBY_CONFIG 0x41
46#define CAP11XX_REG_STANDBY_SENSITIVITY 0x42
47#define CAP11XX_REG_STANDBY_THRESH 0x43
48#define CAP11XX_REG_CONFIG2 0x44
49#define CAP11XX_REG_CONFIG2_ALT_POL BIT(6)
50#define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X))
51#define CAP11XX_REG_LED_POLARITY 0x73
52#define CAP11XX_REG_LED_OUTPUT_CONTROL 0x74
53
54#define CAP11XX_REG_LED_DUTY_CYCLE_1 0x90
55#define CAP11XX_REG_LED_DUTY_CYCLE_2 0x91
56#define CAP11XX_REG_LED_DUTY_CYCLE_3 0x92
57#define CAP11XX_REG_LED_DUTY_CYCLE_4 0x93
58
59#define CAP11XX_REG_LED_DUTY_MIN_MASK (0x0f)
60#define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT (0)
61#define CAP11XX_REG_LED_DUTY_MAX_MASK (0xf0)
62#define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT (4)
63#define CAP11XX_REG_LED_DUTY_MAX_VALUE (15)
64
65#define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X))
66#define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9
67#define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba
68#define CAP11XX_REG_PRODUCT_ID 0xfd
69#define CAP11XX_REG_MANUFACTURER_ID 0xfe
70#define CAP11XX_REG_REVISION 0xff
71
72#define CAP11XX_MANUFACTURER_ID 0x5d
73
74#ifdef CONFIG_LEDS_CLASS
75struct cap11xx_led {
76 struct cap11xx_priv *priv;
77 struct led_classdev cdev;
78 struct work_struct work;
79 u32 reg;
80 enum led_brightness new_brightness;
81};
82#endif
83
84struct cap11xx_priv {
85 struct regmap *regmap;
86 struct input_dev *idev;
87
88 struct cap11xx_led *leds;
89 int num_leds;
90
91 /* config */
92 u32 keycodes[];
93};
94
95struct cap11xx_hw_model {
96 u8 product_id;
97 unsigned int num_channels;
98 unsigned int num_leds;
99};
100
101enum {
102 CAP1106,
103 CAP1126,
104 CAP1188,
105};
106
107static const struct cap11xx_hw_model cap11xx_devices[] = {
108 [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 },
109 [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 },
110 [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 },
111};
112
113static const struct reg_default cap11xx_reg_defaults[] = {
114 { CAP11XX_REG_MAIN_CONTROL, 0x00 },
115 { CAP11XX_REG_GENERAL_STATUS, 0x00 },
116 { CAP11XX_REG_SENSOR_INPUT, 0x00 },
117 { CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 },
118 { CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f },
119 { CAP11XX_REG_CONFIG, 0x20 },
120 { CAP11XX_REG_SENSOR_ENABLE, 0x3f },
121 { CAP11XX_REG_SENSOR_CONFIG, 0xa4 },
122 { CAP11XX_REG_SENSOR_CONFIG2, 0x07 },
123 { CAP11XX_REG_SAMPLING_CONFIG, 0x39 },
124 { CAP11XX_REG_CALIBRATION, 0x00 },
125 { CAP11XX_REG_INT_ENABLE, 0x3f },
126 { CAP11XX_REG_REPEAT_RATE, 0x3f },
127 { CAP11XX_REG_MT_CONFIG, 0x80 },
128 { CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 },
129 { CAP11XX_REG_MT_PATTERN, 0x3f },
130 { CAP11XX_REG_RECALIB_CONFIG, 0x8a },
131 { CAP11XX_REG_SENSOR_THRESH(0), 0x40 },
132 { CAP11XX_REG_SENSOR_THRESH(1), 0x40 },
133 { CAP11XX_REG_SENSOR_THRESH(2), 0x40 },
134 { CAP11XX_REG_SENSOR_THRESH(3), 0x40 },
135 { CAP11XX_REG_SENSOR_THRESH(4), 0x40 },
136 { CAP11XX_REG_SENSOR_THRESH(5), 0x40 },
137 { CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 },
138 { CAP11XX_REG_STANDBY_CHANNEL, 0x00 },
139 { CAP11XX_REG_STANDBY_CONFIG, 0x39 },
140 { CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 },
141 { CAP11XX_REG_STANDBY_THRESH, 0x40 },
142 { CAP11XX_REG_CONFIG2, 0x40 },
143 { CAP11XX_REG_LED_POLARITY, 0x00 },
144 { CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 },
145 { CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 },
146};
147
148static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
149{
150 switch (reg) {
151 case CAP11XX_REG_MAIN_CONTROL:
152 case CAP11XX_REG_SENSOR_INPUT:
153 case CAP11XX_REG_SENOR_DELTA(0):
154 case CAP11XX_REG_SENOR_DELTA(1):
155 case CAP11XX_REG_SENOR_DELTA(2):
156 case CAP11XX_REG_SENOR_DELTA(3):
157 case CAP11XX_REG_SENOR_DELTA(4):
158 case CAP11XX_REG_SENOR_DELTA(5):
159 case CAP11XX_REG_PRODUCT_ID:
160 case CAP11XX_REG_MANUFACTURER_ID:
161 case CAP11XX_REG_REVISION:
162 return true;
163 }
164
165 return false;
166}
167
168static const struct regmap_config cap11xx_regmap_config = {
169 .reg_bits = 8,
170 .val_bits = 8,
171
172 .max_register = CAP11XX_REG_REVISION,
173 .reg_defaults = cap11xx_reg_defaults,
174
175 .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
176 .cache_type = REGCACHE_RBTREE,
177 .volatile_reg = cap11xx_volatile_reg,
178};
179
180static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
181{
182 struct cap11xx_priv *priv = data;
183 unsigned int status;
184 int ret, i;
185
186 /*
187 * Deassert interrupt. This needs to be done before reading the status
188 * registers, which will not carry valid values otherwise.
189 */
190 ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
191 if (ret < 0)
192 goto out;
193
194 ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
195 if (ret < 0)
196 goto out;
197
198 for (i = 0; i < priv->idev->keycodemax; i++)
199 input_report_key(priv->idev, priv->keycodes[i],
200 status & (1 << i));
201
202 input_sync(priv->idev);
203
204out:
205 return IRQ_HANDLED;
206}
207
208static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
209{
210 /*
211 * DLSEEP mode will turn off all LEDS, prevent this
212 */
213 if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds)
214 return 0;
215
216 return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
217 CAP11XX_REG_MAIN_CONTROL_DLSEEP,
218 sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
219}
220
221static int cap11xx_input_open(struct input_dev *idev)
222{
223 struct cap11xx_priv *priv = input_get_drvdata(idev);
224
225 return cap11xx_set_sleep(priv, false);
226}
227
228static void cap11xx_input_close(struct input_dev *idev)
229{
230 struct cap11xx_priv *priv = input_get_drvdata(idev);
231
232 cap11xx_set_sleep(priv, true);
233}
234
235#ifdef CONFIG_LEDS_CLASS
236static void cap11xx_led_work(struct work_struct *work)
237{
238 struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
239 struct cap11xx_priv *priv = led->priv;
240 int value = led->new_brightness;
241
242 /*
243 * All LEDs share the same duty cycle as this is a HW limitation.
244 * Brightness levels per LED are either 0 (OFF) and 1 (ON).
245 */
246 regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
247 BIT(led->reg), value ? BIT(led->reg) : 0);
248}
249
250static void cap11xx_led_set(struct led_classdev *cdev,
251 enum led_brightness value)
252{
253 struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
254
255 if (led->new_brightness == value)
256 return;
257
258 led->new_brightness = value;
259 schedule_work(&led->work);
260}
261
262static int cap11xx_init_leds(struct device *dev,
263 struct cap11xx_priv *priv, int num_leds)
264{
265 struct device_node *node = dev->of_node, *child;
266 struct cap11xx_led *led;
267 int cnt = of_get_child_count(node);
268 int error;
269
270 if (!num_leds || !cnt)
271 return 0;
272
273 if (cnt > num_leds)
274 return -EINVAL;
275
276 led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL);
277 if (!led)
278 return -ENOMEM;
279
280 priv->leds = led;
281
282 error = regmap_update_bits(priv->regmap,
283 CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
284 if (error)
285 return error;
286
287 error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4,
288 CAP11XX_REG_LED_DUTY_MAX_MASK,
289 CAP11XX_REG_LED_DUTY_MAX_VALUE <<
290 CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT);
291 if (error)
292 return error;
293
294 for_each_child_of_node(node, child) {
295 u32 reg;
296
297 led->cdev.name =
298 of_get_property(child, "label", NULL) ? : child->name;
299 led->cdev.default_trigger =
300 of_get_property(child, "linux,default-trigger", NULL);
301 led->cdev.flags = 0;
302 led->cdev.brightness_set = cap11xx_led_set;
303 led->cdev.max_brightness = 1;
304 led->cdev.brightness = LED_OFF;
305
306 error = of_property_read_u32(child, "reg", ®);
307 if (error != 0 || reg >= num_leds) {
308 of_node_put(child);
309 return -EINVAL;
310 }
311
312 led->reg = reg;
313 led->priv = priv;
314
315 INIT_WORK(&led->work, cap11xx_led_work);
316
317 error = devm_led_classdev_register(dev, &led->cdev);
318 if (error) {
319 of_node_put(child);
320 return error;
321 }
322
323 priv->num_leds++;
324 led++;
325 }
326
327 return 0;
328}
329#else
330static int cap11xx_init_leds(struct device *dev,
331 struct cap11xx_priv *priv, int num_leds)
332{
333 return 0;
334}
335#endif
336
337static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
338 const struct i2c_device_id *id)
339{
340 struct device *dev = &i2c_client->dev;
341 struct cap11xx_priv *priv;
342 struct device_node *node;
343 const struct cap11xx_hw_model *cap;
344 int i, error, irq, gain = 0;
345 unsigned int val, rev;
346 u32 gain32;
347
348 if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
349 dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
350 return -EINVAL;
351 }
352
353 cap = &cap11xx_devices[id->driver_data];
354 if (!cap || !cap->num_channels) {
355 dev_err(dev, "Invalid device configuration\n");
356 return -EINVAL;
357 }
358
359 priv = devm_kzalloc(dev,
360 sizeof(*priv) +
361 cap->num_channels * sizeof(priv->keycodes[0]),
362 GFP_KERNEL);
363 if (!priv)
364 return -ENOMEM;
365
366 priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
367 if (IS_ERR(priv->regmap))
368 return PTR_ERR(priv->regmap);
369
370 error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
371 if (error)
372 return error;
373
374 if (val != cap->product_id) {
375 dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
376 val, cap->product_id);
377 return -ENXIO;
378 }
379
380 error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
381 if (error)
382 return error;
383
384 if (val != CAP11XX_MANUFACTURER_ID) {
385 dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
386 val, CAP11XX_MANUFACTURER_ID);
387 return -ENXIO;
388 }
389
390 error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
391 if (error < 0)
392 return error;
393
394 dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev);
395 i2c_set_clientdata(i2c_client, priv);
396 node = dev->of_node;
397
398 if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {
399 if (is_power_of_2(gain32) && gain32 <= 8)
400 gain = ilog2(gain32);
401 else
402 dev_err(dev, "Invalid sensor-gain value %d\n", gain32);
403 }
404
405 if (of_property_read_bool(node, "microchip,irq-active-high")) {
406 error = regmap_update_bits(priv->regmap, CAP11XX_REG_CONFIG2,
407 CAP11XX_REG_CONFIG2_ALT_POL, 0);
408 if (error)
409 return error;
410 }
411
412 /* Provide some useful defaults */
413 for (i = 0; i < cap->num_channels; i++)
414 priv->keycodes[i] = KEY_A + i;
415
416 of_property_read_u32_array(node, "linux,keycodes",
417 priv->keycodes, cap->num_channels);
418
419 error = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
420 CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
421 gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
422 if (error)
423 return error;
424
425 /* Disable autorepeat. The Linux input system has its own handling. */
426 error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
427 if (error)
428 return error;
429
430 priv->idev = devm_input_allocate_device(dev);
431 if (!priv->idev)
432 return -ENOMEM;
433
434 priv->idev->name = "CAP11XX capacitive touch sensor";
435 priv->idev->id.bustype = BUS_I2C;
436 priv->idev->evbit[0] = BIT_MASK(EV_KEY);
437
438 if (of_property_read_bool(node, "autorepeat"))
439 __set_bit(EV_REP, priv->idev->evbit);
440
441 for (i = 0; i < cap->num_channels; i++)
442 __set_bit(priv->keycodes[i], priv->idev->keybit);
443
444 __clear_bit(KEY_RESERVED, priv->idev->keybit);
445
446 priv->idev->keycode = priv->keycodes;
447 priv->idev->keycodesize = sizeof(priv->keycodes[0]);
448 priv->idev->keycodemax = cap->num_channels;
449
450 priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
451 priv->idev->id.product = cap->product_id;
452 priv->idev->id.version = rev;
453
454 priv->idev->open = cap11xx_input_open;
455 priv->idev->close = cap11xx_input_close;
456
457 error = cap11xx_init_leds(dev, priv, cap->num_leds);
458 if (error)
459 return error;
460
461 input_set_drvdata(priv->idev, priv);
462
463 /*
464 * Put the device in deep sleep mode for now.
465 * ->open() will bring it back once the it is actually needed.
466 */
467 cap11xx_set_sleep(priv, true);
468
469 error = input_register_device(priv->idev);
470 if (error)
471 return error;
472
473 irq = irq_of_parse_and_map(node, 0);
474 if (!irq) {
475 dev_err(dev, "Unable to parse or map IRQ\n");
476 return -ENXIO;
477 }
478
479 error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func,
480 IRQF_ONESHOT, dev_name(dev), priv);
481 if (error)
482 return error;
483
484 return 0;
485}
486
487static const struct of_device_id cap11xx_dt_ids[] = {
488 { .compatible = "microchip,cap1106", },
489 { .compatible = "microchip,cap1126", },
490 { .compatible = "microchip,cap1188", },
491 {}
492};
493MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
494
495static const struct i2c_device_id cap11xx_i2c_ids[] = {
496 { "cap1106", CAP1106 },
497 { "cap1126", CAP1126 },
498 { "cap1188", CAP1188 },
499 {}
500};
501MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
502
503static struct i2c_driver cap11xx_i2c_driver = {
504 .driver = {
505 .name = "cap11xx",
506 .of_match_table = cap11xx_dt_ids,
507 },
508 .id_table = cap11xx_i2c_ids,
509 .probe = cap11xx_i2c_probe,
510};
511
512module_i2c_driver(cap11xx_i2c_driver);
513
514MODULE_DESCRIPTION("Microchip CAP11XX driver");
515MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
516MODULE_LICENSE("GPL v2");