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