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