2 * Input driver for Microchip CAP11xx based capacitive touch sensors
4 * (c) 2014 Daniel Mack <linux@zonque.org>
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.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/input.h>
15 #include <linux/of_irq.h>
16 #include <linux/regmap.h>
17 #include <linux/i2c.h>
18 #include <linux/gpio/consumer.h>
20 #define CAP11XX_REG_MAIN_CONTROL 0x00
21 #define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6)
22 #define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0)
23 #define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4)
24 #define CAP11XX_REG_GENERAL_STATUS 0x02
25 #define CAP11XX_REG_SENSOR_INPUT 0x03
26 #define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a
27 #define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X))
28 #define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f
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_MT_CONFIG 0x2a
38 #define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b
39 #define CAP11XX_REG_MT_PATTERN 0x2d
40 #define CAP11XX_REG_RECALIB_CONFIG 0x2f
41 #define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X))
42 #define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38
43 #define CAP11XX_REG_STANDBY_CHANNEL 0x40
44 #define CAP11XX_REG_STANDBY_CONFIG 0x41
45 #define CAP11XX_REG_STANDBY_SENSITIVITY 0x42
46 #define CAP11XX_REG_STANDBY_THRESH 0x43
47 #define CAP11XX_REG_CONFIG2 0x44
48 #define CAP11XX_REG_CONFIG2_ALT_POL BIT(6)
49 #define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X))
50 #define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X))
51 #define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9
52 #define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba
53 #define CAP11XX_REG_PRODUCT_ID 0xfd
54 #define CAP11XX_REG_MANUFACTURER_ID 0xfe
55 #define CAP11XX_REG_REVISION 0xff
57 #define CAP11XX_MANUFACTURER_ID 0x5d
60 struct regmap *regmap;
61 struct input_dev *idev;
67 struct cap11xx_hw_model {
69 unsigned int num_channels;
78 static const struct cap11xx_hw_model cap11xx_devices[] = {
79 [CAP1106] = { .product_id = 0x55, .num_channels = 6 },
80 [CAP1126] = { .product_id = 0x53, .num_channels = 6 },
81 [CAP1188] = { .product_id = 0x50, .num_channels = 8 },
84 static const struct reg_default cap11xx_reg_defaults[] = {
85 { CAP11XX_REG_MAIN_CONTROL, 0x00 },
86 { CAP11XX_REG_GENERAL_STATUS, 0x00 },
87 { CAP11XX_REG_SENSOR_INPUT, 0x00 },
88 { CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 },
89 { CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f },
90 { CAP11XX_REG_CONFIG, 0x20 },
91 { CAP11XX_REG_SENSOR_ENABLE, 0x3f },
92 { CAP11XX_REG_SENSOR_CONFIG, 0xa4 },
93 { CAP11XX_REG_SENSOR_CONFIG2, 0x07 },
94 { CAP11XX_REG_SAMPLING_CONFIG, 0x39 },
95 { CAP11XX_REG_CALIBRATION, 0x00 },
96 { CAP11XX_REG_INT_ENABLE, 0x3f },
97 { CAP11XX_REG_REPEAT_RATE, 0x3f },
98 { CAP11XX_REG_MT_CONFIG, 0x80 },
99 { CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 },
100 { CAP11XX_REG_MT_PATTERN, 0x3f },
101 { CAP11XX_REG_RECALIB_CONFIG, 0x8a },
102 { CAP11XX_REG_SENSOR_THRESH(0), 0x40 },
103 { CAP11XX_REG_SENSOR_THRESH(1), 0x40 },
104 { CAP11XX_REG_SENSOR_THRESH(2), 0x40 },
105 { CAP11XX_REG_SENSOR_THRESH(3), 0x40 },
106 { CAP11XX_REG_SENSOR_THRESH(4), 0x40 },
107 { CAP11XX_REG_SENSOR_THRESH(5), 0x40 },
108 { CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 },
109 { CAP11XX_REG_STANDBY_CHANNEL, 0x00 },
110 { CAP11XX_REG_STANDBY_CONFIG, 0x39 },
111 { CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 },
112 { CAP11XX_REG_STANDBY_THRESH, 0x40 },
113 { CAP11XX_REG_CONFIG2, 0x40 },
114 { CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 },
115 { CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 },
118 static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
121 case CAP11XX_REG_MAIN_CONTROL:
122 case CAP11XX_REG_SENSOR_INPUT:
123 case CAP11XX_REG_SENOR_DELTA(0):
124 case CAP11XX_REG_SENOR_DELTA(1):
125 case CAP11XX_REG_SENOR_DELTA(2):
126 case CAP11XX_REG_SENOR_DELTA(3):
127 case CAP11XX_REG_SENOR_DELTA(4):
128 case CAP11XX_REG_SENOR_DELTA(5):
129 case CAP11XX_REG_PRODUCT_ID:
130 case CAP11XX_REG_MANUFACTURER_ID:
131 case CAP11XX_REG_REVISION:
138 static const struct regmap_config cap11xx_regmap_config = {
142 .max_register = CAP11XX_REG_REVISION,
143 .reg_defaults = cap11xx_reg_defaults,
145 .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
146 .cache_type = REGCACHE_RBTREE,
147 .volatile_reg = cap11xx_volatile_reg,
150 static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
152 struct cap11xx_priv *priv = data;
157 * Deassert interrupt. This needs to be done before reading the status
158 * registers, which will not carry valid values otherwise.
160 ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
164 ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
168 for (i = 0; i < priv->idev->keycodemax; i++)
169 input_report_key(priv->idev, priv->keycodes[i],
172 input_sync(priv->idev);
178 static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
180 return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
181 CAP11XX_REG_MAIN_CONTROL_DLSEEP,
182 sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
185 static int cap11xx_input_open(struct input_dev *idev)
187 struct cap11xx_priv *priv = input_get_drvdata(idev);
189 return cap11xx_set_sleep(priv, false);
192 static void cap11xx_input_close(struct input_dev *idev)
194 struct cap11xx_priv *priv = input_get_drvdata(idev);
196 cap11xx_set_sleep(priv, true);
199 static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
200 const struct i2c_device_id *id)
202 struct device *dev = &i2c_client->dev;
203 struct cap11xx_priv *priv;
204 struct device_node *node;
205 const struct cap11xx_hw_model *cap;
206 int i, error, irq, gain = 0;
207 unsigned int val, rev;
210 if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
211 dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
215 cap = &cap11xx_devices[id->driver_data];
216 if (!cap || !cap->num_channels) {
217 dev_err(dev, "Invalid device configuration\n");
221 priv = devm_kzalloc(dev,
223 cap->num_channels * sizeof(priv->keycodes[0]),
228 priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
229 if (IS_ERR(priv->regmap))
230 return PTR_ERR(priv->regmap);
232 error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
236 if (val != cap->product_id) {
237 dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
238 val, cap->product_id);
242 error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
246 if (val != CAP11XX_MANUFACTURER_ID) {
247 dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
248 val, CAP11XX_MANUFACTURER_ID);
252 error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
256 dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev);
257 i2c_set_clientdata(i2c_client, priv);
260 if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {
261 if (is_power_of_2(gain32) && gain32 <= 8)
262 gain = ilog2(gain32);
264 dev_err(dev, "Invalid sensor-gain value %d\n", gain32);
267 if (of_property_read_bool(node, "microchip,irq-active-high")) {
268 error = regmap_update_bits(priv->regmap, CAP11XX_REG_CONFIG2,
269 CAP11XX_REG_CONFIG2_ALT_POL, 0);
274 /* Provide some useful defaults */
275 for (i = 0; i < cap->num_channels; i++)
276 priv->keycodes[i] = KEY_A + i;
278 of_property_read_u32_array(node, "linux,keycodes",
279 priv->keycodes, cap->num_channels);
281 error = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
282 CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
283 gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
287 /* Disable autorepeat. The Linux input system has its own handling. */
288 error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
292 priv->idev = devm_input_allocate_device(dev);
296 priv->idev->name = "CAP11XX capacitive touch sensor";
297 priv->idev->id.bustype = BUS_I2C;
298 priv->idev->evbit[0] = BIT_MASK(EV_KEY);
300 if (of_property_read_bool(node, "autorepeat"))
301 __set_bit(EV_REP, priv->idev->evbit);
303 for (i = 0; i < cap->num_channels; i++)
304 __set_bit(priv->keycodes[i], priv->idev->keybit);
306 __clear_bit(KEY_RESERVED, priv->idev->keybit);
308 priv->idev->keycode = priv->keycodes;
309 priv->idev->keycodesize = sizeof(priv->keycodes[0]);
310 priv->idev->keycodemax = cap->num_channels;
312 priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
313 priv->idev->id.product = cap->product_id;
314 priv->idev->id.version = rev;
316 priv->idev->open = cap11xx_input_open;
317 priv->idev->close = cap11xx_input_close;
319 input_set_drvdata(priv->idev, priv);
322 * Put the device in deep sleep mode for now.
323 * ->open() will bring it back once the it is actually needed.
325 cap11xx_set_sleep(priv, true);
327 error = input_register_device(priv->idev);
331 irq = irq_of_parse_and_map(node, 0);
333 dev_err(dev, "Unable to parse or map IRQ\n");
337 error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func,
338 IRQF_ONESHOT, dev_name(dev), priv);
345 static const struct of_device_id cap11xx_dt_ids[] = {
346 { .compatible = "microchip,cap1106", },
347 { .compatible = "microchip,cap1126", },
348 { .compatible = "microchip,cap1188", },
351 MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
353 static const struct i2c_device_id cap11xx_i2c_ids[] = {
354 { "cap1106", CAP1106 },
355 { "cap1126", CAP1126 },
356 { "cap1188", CAP1188 },
359 MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
361 static struct i2c_driver cap11xx_i2c_driver = {
364 .owner = THIS_MODULE,
365 .of_match_table = cap11xx_dt_ids,
367 .id_table = cap11xx_i2c_ids,
368 .probe = cap11xx_i2c_probe,
371 module_i2c_driver(cap11xx_i2c_driver);
373 MODULE_DESCRIPTION("Microchip CAP11XX driver");
374 MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
375 MODULE_LICENSE("GPL v2");