input/keyboard/cap11xx.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Input driver for Microchip CAP11xx based capacitive touch sensors
0004  *
0005  * (c) 2014 Daniel Mack <linux@zonque.org>
0006  */
0007
0008 #include <linux/kernel.h>
0009 #include <linux/module.h>
0010 #include <linux/interrupt.h>
0011 #include <linux/input.h>
0012 #include <linux/leds.h>
0013 #include <linux/of_irq.h>
0014 #include <linux/regmap.h>
0015 #include <linux/i2c.h>
0016 #include <linux/gpio/consumer.h>
0017
0018 #define CAP11XX_REG_MAIN_CONTROL    0x00
0019 #define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6)
0020 #define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK  (0xc0)
0021 #define CAP11XX_REG_MAIN_CONTROL_DLSEEP     BIT(4)
0022 #define CAP11XX_REG_GENERAL_STATUS  0x02
0023 #define CAP11XX_REG_SENSOR_INPUT    0x03
0024 #define CAP11XX_REG_NOISE_FLAG_STATUS   0x0a
0025 #define CAP11XX_REG_SENOR_DELTA(X)  (0x10 + (X))
0026 #define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f
0027 #define CAP11XX_REG_CONFIG      0x20
0028 #define CAP11XX_REG_SENSOR_ENABLE   0x21
0029 #define CAP11XX_REG_SENSOR_CONFIG   0x22
0030 #define CAP11XX_REG_SENSOR_CONFIG2  0x23
0031 #define CAP11XX_REG_SAMPLING_CONFIG 0x24
0032 #define CAP11XX_REG_CALIBRATION     0x26
0033 #define CAP11XX_REG_INT_ENABLE      0x27
0034 #define CAP11XX_REG_REPEAT_RATE     0x28
0035 #define CAP11XX_REG_MT_CONFIG       0x2a
0036 #define CAP11XX_REG_MT_PATTERN_CONFIG   0x2b
0037 #define CAP11XX_REG_MT_PATTERN      0x2d
0038 #define CAP11XX_REG_RECALIB_CONFIG  0x2f
0039 #define CAP11XX_REG_SENSOR_THRESH(X)    (0x30 + (X))
0040 #define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38
0041 #define CAP11XX_REG_STANDBY_CHANNEL 0x40
0042 #define CAP11XX_REG_STANDBY_CONFIG  0x41
0043 #define CAP11XX_REG_STANDBY_SENSITIVITY 0x42
0044 #define CAP11XX_REG_STANDBY_THRESH  0x43
0045 #define CAP11XX_REG_CONFIG2     0x44
0046 #define CAP11XX_REG_CONFIG2_ALT_POL BIT(6)
0047 #define CAP11XX_REG_SENSOR_BASE_CNT(X)  (0x50 + (X))
0048 #define CAP11XX_REG_LED_POLARITY    0x73
0049 #define CAP11XX_REG_LED_OUTPUT_CONTROL  0x74
0050
0051 #define CAP11XX_REG_LED_DUTY_CYCLE_1    0x90
0052 #define CAP11XX_REG_LED_DUTY_CYCLE_2    0x91
0053 #define CAP11XX_REG_LED_DUTY_CYCLE_3    0x92
0054 #define CAP11XX_REG_LED_DUTY_CYCLE_4    0x93
0055
0056 #define CAP11XX_REG_LED_DUTY_MIN_MASK   (0x0f)
0057 #define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT (0)
0058 #define CAP11XX_REG_LED_DUTY_MAX_MASK   (0xf0)
0059 #define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT (4)
0060 #define CAP11XX_REG_LED_DUTY_MAX_VALUE  (15)
0061
0062 #define CAP11XX_REG_SENSOR_CALIB    (0xb1 + (X))
0063 #define CAP11XX_REG_SENSOR_CALIB_LSB1   0xb9
0064 #define CAP11XX_REG_SENSOR_CALIB_LSB2   0xba
0065 #define CAP11XX_REG_PRODUCT_ID      0xfd
0066 #define CAP11XX_REG_MANUFACTURER_ID 0xfe
0067 #define CAP11XX_REG_REVISION        0xff
0068
0069 #define CAP11XX_MANUFACTURER_ID 0x5d
0070
0071 #ifdef CONFIG_LEDS_CLASS
0072 struct cap11xx_led {
0073     struct cap11xx_priv *priv;
0074     struct led_classdev cdev;
0075     u32 reg;
0076 };
0077 #endif
0078
0079 struct cap11xx_priv {
0080     struct regmap *regmap;
0081     struct input_dev *idev;
0082
0083     struct cap11xx_led *leds;
0084     int num_leds;
0085
0086     /* config */
0087     u32 keycodes[];
0088 };
0089
0090 struct cap11xx_hw_model {
0091     u8 product_id;
0092     unsigned int num_channels;
0093     unsigned int num_leds;
0094     bool no_gain;
0095 };
0096
0097 enum {
0098     CAP1106,
0099     CAP1126,
0100     CAP1188,
0101     CAP1206,
0102 };
0103
0104 static const struct cap11xx_hw_model cap11xx_devices[] = {
0105     [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0, .no_gain = false },
0106     [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2, .no_gain = false },
0107     [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8, .no_gain = false },
0108     [CAP1206] = { .product_id = 0x67, .num_channels = 6, .num_leds = 0, .no_gain = true },
0109 };
0110
0111 static const struct reg_default cap11xx_reg_defaults[] = {
0112     { CAP11XX_REG_MAIN_CONTROL,     0x00 },
0113     { CAP11XX_REG_GENERAL_STATUS,       0x00 },
0114     { CAP11XX_REG_SENSOR_INPUT,     0x00 },
0115     { CAP11XX_REG_NOISE_FLAG_STATUS,    0x00 },
0116     { CAP11XX_REG_SENSITIVITY_CONTROL,  0x2f },
0117     { CAP11XX_REG_CONFIG,           0x20 },
0118     { CAP11XX_REG_SENSOR_ENABLE,        0x3f },
0119     { CAP11XX_REG_SENSOR_CONFIG,        0xa4 },
0120     { CAP11XX_REG_SENSOR_CONFIG2,       0x07 },
0121     { CAP11XX_REG_SAMPLING_CONFIG,      0x39 },
0122     { CAP11XX_REG_CALIBRATION,      0x00 },
0123     { CAP11XX_REG_INT_ENABLE,       0x3f },
0124     { CAP11XX_REG_REPEAT_RATE,      0x3f },
0125     { CAP11XX_REG_MT_CONFIG,        0x80 },
0126     { CAP11XX_REG_MT_PATTERN_CONFIG,    0x00 },
0127     { CAP11XX_REG_MT_PATTERN,       0x3f },
0128     { CAP11XX_REG_RECALIB_CONFIG,       0x8a },
0129     { CAP11XX_REG_SENSOR_THRESH(0),     0x40 },
0130     { CAP11XX_REG_SENSOR_THRESH(1),     0x40 },
0131     { CAP11XX_REG_SENSOR_THRESH(2),     0x40 },
0132     { CAP11XX_REG_SENSOR_THRESH(3),     0x40 },
0133     { CAP11XX_REG_SENSOR_THRESH(4),     0x40 },
0134     { CAP11XX_REG_SENSOR_THRESH(5),     0x40 },
0135     { CAP11XX_REG_SENSOR_NOISE_THRESH,  0x01 },
0136     { CAP11XX_REG_STANDBY_CHANNEL,      0x00 },
0137     { CAP11XX_REG_STANDBY_CONFIG,       0x39 },
0138     { CAP11XX_REG_STANDBY_SENSITIVITY,  0x02 },
0139     { CAP11XX_REG_STANDBY_THRESH,       0x40 },
0140     { CAP11XX_REG_CONFIG2,          0x40 },
0141     { CAP11XX_REG_LED_POLARITY,     0x00 },
0142     { CAP11XX_REG_SENSOR_CALIB_LSB1,    0x00 },
0143     { CAP11XX_REG_SENSOR_CALIB_LSB2,    0x00 },
0144 };
0145
0146 static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
0147 {
0148     switch (reg) {
0149     case CAP11XX_REG_MAIN_CONTROL:
0150     case CAP11XX_REG_SENSOR_INPUT:
0151     case CAP11XX_REG_SENOR_DELTA(0):
0152     case CAP11XX_REG_SENOR_DELTA(1):
0153     case CAP11XX_REG_SENOR_DELTA(2):
0154     case CAP11XX_REG_SENOR_DELTA(3):
0155     case CAP11XX_REG_SENOR_DELTA(4):
0156     case CAP11XX_REG_SENOR_DELTA(5):
0157     case CAP11XX_REG_PRODUCT_ID:
0158     case CAP11XX_REG_MANUFACTURER_ID:
0159     case CAP11XX_REG_REVISION:
0160         return true;
0161     }
0162
0163     return false;
0164 }
0165
0166 static const struct regmap_config cap11xx_regmap_config = {
0167     .reg_bits = 8,
0168     .val_bits = 8,
0169
0170     .max_register = CAP11XX_REG_REVISION,
0171     .reg_defaults = cap11xx_reg_defaults,
0172
0173     .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
0174     .cache_type = REGCACHE_RBTREE,
0175     .volatile_reg = cap11xx_volatile_reg,
0176 };
0177
0178 static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
0179 {
0180     struct cap11xx_priv *priv = data;
0181     unsigned int status;
0182     int ret, i;
0183
0184     /*
0185      * Deassert interrupt. This needs to be done before reading the status
0186      * registers, which will not carry valid values otherwise.
0187      */
0188     ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
0189     if (ret < 0)
0190         goto out;
0191
0192     ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
0193     if (ret < 0)
0194         goto out;
0195
0196     for (i = 0; i < priv->idev->keycodemax; i++)
0197         input_report_key(priv->idev, priv->keycodes[i],
0198                  status & (1 << i));
0199
0200     input_sync(priv->idev);
0201
0202 out:
0203     return IRQ_HANDLED;
0204 }
0205
0206 static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
0207 {
0208     /*
0209      * DLSEEP mode will turn off all LEDS, prevent this
0210      */
0211     if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds)
0212         return 0;
0213
0214     return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
0215                   CAP11XX_REG_MAIN_CONTROL_DLSEEP,
0216                   sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
0217 }
0218
0219 static int cap11xx_input_open(struct input_dev *idev)
0220 {
0221     struct cap11xx_priv *priv = input_get_drvdata(idev);
0222
0223     return cap11xx_set_sleep(priv, false);
0224 }
0225
0226 static void cap11xx_input_close(struct input_dev *idev)
0227 {
0228     struct cap11xx_priv *priv = input_get_drvdata(idev);
0229
0230     cap11xx_set_sleep(priv, true);
0231 }
0232
0233 #ifdef CONFIG_LEDS_CLASS
0234 static int cap11xx_led_set(struct led_classdev *cdev,
0235                 enum led_brightness value)
0236 {
0237     struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
0238     struct cap11xx_priv *priv = led->priv;
0239
0240     /*
0241      * All LEDs share the same duty cycle as this is a HW
0242      * limitation. Brightness levels per LED are either
0243      * 0 (OFF) and 1 (ON).
0244      */
0245     return regmap_update_bits(priv->regmap,
0246                   CAP11XX_REG_LED_OUTPUT_CONTROL,
0247                   BIT(led->reg),
0248                   value ? BIT(led->reg) : 0);
0249 }
0250
0251 static int cap11xx_init_leds(struct device *dev,
0252                  struct cap11xx_priv *priv, int num_leds)
0253 {
0254     struct device_node *node = dev->of_node, *child;
0255     struct cap11xx_led *led;
0256     int cnt = of_get_child_count(node);
0257     int error;
0258
0259     if (!num_leds || !cnt)
0260         return 0;
0261
0262     if (cnt > num_leds)
0263         return -EINVAL;
0264
0265     led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL);
0266     if (!led)
0267         return -ENOMEM;
0268
0269     priv->leds = led;
0270
0271     error = regmap_update_bits(priv->regmap,
0272                 CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
0273     if (error)
0274         return error;
0275
0276     error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4,
0277                 CAP11XX_REG_LED_DUTY_MAX_MASK,
0278                 CAP11XX_REG_LED_DUTY_MAX_VALUE <<
0279                 CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT);
0280     if (error)
0281         return error;
0282
0283     for_each_child_of_node(node, child) {
0284         u32 reg;
0285
0286         led->cdev.name =
0287             of_get_property(child, "label", NULL) ? : child->name;
0288         led->cdev.default_trigger =
0289             of_get_property(child, "linux,default-trigger", NULL);
0290         led->cdev.flags = 0;
0291         led->cdev.brightness_set_blocking = cap11xx_led_set;
0292         led->cdev.max_brightness = 1;
0293         led->cdev.brightness = LED_OFF;
0294
0295         error = of_property_read_u32(child, "reg", &reg);
0296         if (error != 0 || reg >= num_leds) {
0297             of_node_put(child);
0298             return -EINVAL;
0299         }
0300
0301         led->reg = reg;
0302         led->priv = priv;
0303
0304         error = devm_led_classdev_register(dev, &led->cdev);
0305         if (error) {
0306             of_node_put(child);
0307             return error;
0308         }
0309
0310         priv->num_leds++;
0311         led++;
0312     }
0313
0314     return 0;
0315 }
0316 #else
0317 static int cap11xx_init_leds(struct device *dev,
0318                  struct cap11xx_priv *priv, int num_leds)
0319 {
0320     return 0;
0321 }
0322 #endif
0323
0324 static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
0325                  const struct i2c_device_id *id)
0326 {
0327     struct device *dev = &i2c_client->dev;
0328     struct cap11xx_priv *priv;
0329     struct device_node *node;
0330     const struct cap11xx_hw_model *cap;
0331     int i, error, irq, gain = 0;
0332     unsigned int val, rev;
0333     u32 gain32;
0334
0335     if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
0336         dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
0337         return -EINVAL;
0338     }
0339
0340     cap = &cap11xx_devices[id->driver_data];
0341     if (!cap || !cap->num_channels) {
0342         dev_err(dev, "Invalid device configuration\n");
0343         return -EINVAL;
0344     }
0345
0346     priv = devm_kzalloc(dev,
0347                 struct_size(priv, keycodes, cap->num_channels),
0348                 GFP_KERNEL);
0349     if (!priv)
0350         return -ENOMEM;
0351
0352     priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
0353     if (IS_ERR(priv->regmap))
0354         return PTR_ERR(priv->regmap);
0355
0356     error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
0357     if (error)
0358         return error;
0359
0360     if (val != cap->product_id) {
0361         dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
0362             val, cap->product_id);
0363         return -ENXIO;
0364     }
0365
0366     error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
0367     if (error)
0368         return error;
0369
0370     if (val != CAP11XX_MANUFACTURER_ID) {
0371         dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
0372             val, CAP11XX_MANUFACTURER_ID);
0373         return -ENXIO;
0374     }
0375
0376     error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
0377     if (error < 0)
0378         return error;
0379
0380     dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev);
0381     node = dev->of_node;
0382
0383     if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {
0384         if (cap->no_gain)
0385             dev_warn(dev,
0386                  "This version doesn't support sensor gain\n");
0387         else if (is_power_of_2(gain32) && gain32 <= 8)
0388             gain = ilog2(gain32);
0389         else
0390             dev_err(dev, "Invalid sensor-gain value %d\n", gain32);
0391     }
0392
0393     if (id->driver_data != CAP1206) {
0394         if (of_property_read_bool(node, "microchip,irq-active-high")) {
0395             error = regmap_update_bits(priv->regmap,
0396                            CAP11XX_REG_CONFIG2,
0397                            CAP11XX_REG_CONFIG2_ALT_POL,
0398                            0);
0399             if (error)
0400                 return error;
0401         }
0402     }
0403
0404     /* Provide some useful defaults */
0405     for (i = 0; i < cap->num_channels; i++)
0406         priv->keycodes[i] = KEY_A + i;
0407
0408     of_property_read_u32_array(node, "linux,keycodes",
0409                    priv->keycodes, cap->num_channels);
0410
0411     if (!cap->no_gain) {
0412         error = regmap_update_bits(priv->regmap,
0413                 CAP11XX_REG_MAIN_CONTROL,
0414                 CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
0415                 gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
0416         if (error)
0417             return error;
0418     }
0419
0420     /* Disable autorepeat. The Linux input system has its own handling. */
0421     error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
0422     if (error)
0423         return error;
0424
0425     priv->idev = devm_input_allocate_device(dev);
0426     if (!priv->idev)
0427         return -ENOMEM;
0428
0429     priv->idev->name = "CAP11XX capacitive touch sensor";
0430     priv->idev->id.bustype = BUS_I2C;
0431     priv->idev->evbit[0] = BIT_MASK(EV_KEY);
0432
0433     if (of_property_read_bool(node, "autorepeat"))
0434         __set_bit(EV_REP, priv->idev->evbit);
0435
0436     for (i = 0; i < cap->num_channels; i++)
0437         __set_bit(priv->keycodes[i], priv->idev->keybit);
0438
0439     __clear_bit(KEY_RESERVED, priv->idev->keybit);
0440
0441     priv->idev->keycode = priv->keycodes;
0442     priv->idev->keycodesize = sizeof(priv->keycodes[0]);
0443     priv->idev->keycodemax = cap->num_channels;
0444
0445     priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
0446     priv->idev->id.product = cap->product_id;
0447     priv->idev->id.version = rev;
0448
0449     priv->idev->open = cap11xx_input_open;
0450     priv->idev->close = cap11xx_input_close;
0451
0452     error = cap11xx_init_leds(dev, priv, cap->num_leds);
0453     if (error)
0454         return error;
0455
0456     input_set_drvdata(priv->idev, priv);
0457
0458     /*
0459      * Put the device in deep sleep mode for now.
0460      * ->open() will bring it back once the it is actually needed.
0461      */
0462     cap11xx_set_sleep(priv, true);
0463
0464     error = input_register_device(priv->idev);
0465     if (error)
0466         return error;
0467
0468     irq = irq_of_parse_and_map(node, 0);
0469     if (!irq) {
0470         dev_err(dev, "Unable to parse or map IRQ\n");
0471         return -ENXIO;
0472     }
0473
0474     error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func,
0475                       IRQF_ONESHOT, dev_name(dev), priv);
0476     if (error)
0477         return error;
0478
0479     return 0;
0480 }
0481
0482 static const struct of_device_id cap11xx_dt_ids[] = {
0483     { .compatible = "microchip,cap1106", },
0484     { .compatible = "microchip,cap1126", },
0485     { .compatible = "microchip,cap1188", },
0486     { .compatible = "microchip,cap1206", },
0487     {}
0488 };
0489 MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
0490
0491 static const struct i2c_device_id cap11xx_i2c_ids[] = {
0492     { "cap1106", CAP1106 },
0493     { "cap1126", CAP1126 },
0494     { "cap1188", CAP1188 },
0495     { "cap1206", CAP1206 },
0496     {}
0497 };
0498 MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
0499
0500 static struct i2c_driver cap11xx_i2c_driver = {
0501     .driver = {
0502         .name   = "cap11xx",
0503         .of_match_table = cap11xx_dt_ids,
0504     },
0505     .id_table   = cap11xx_i2c_ids,
0506     .probe      = cap11xx_i2c_probe,
0507 };
0508
0509 module_i2c_driver(cap11xx_i2c_driver);
0510
0511 MODULE_DESCRIPTION("Microchip CAP11XX driver");
0512 MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
0513 MODULE_LICENSE("GPL v2");