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/of_irq.h> 16 #include <linux/regmap.h> 17 #include <linux/i2c.h> 18 #include <linux/gpio/consumer.h> 19 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 56 57 #define CAP11XX_MANUFACTURER_ID 0x5d 58 59 struct cap11xx_priv { 60 struct regmap *regmap; 61 struct input_dev *idev; 62 63 /* config */ 64 u32 keycodes[]; 65 }; 66 67 struct cap11xx_hw_model { 68 u8 product_id; 69 unsigned int num_channels; 70 }; 71 72 enum { 73 CAP1106, 74 CAP1126, 75 CAP1188, 76 }; 77 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 }, 82 }; 83 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 }, 116 }; 117 118 static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg) 119 { 120 switch (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: 132 return true; 133 } 134 135 return false; 136 } 137 138 static const struct regmap_config cap11xx_regmap_config = { 139 .reg_bits = 8, 140 .val_bits = 8, 141 142 .max_register = CAP11XX_REG_REVISION, 143 .reg_defaults = cap11xx_reg_defaults, 144 145 .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults), 146 .cache_type = REGCACHE_RBTREE, 147 .volatile_reg = cap11xx_volatile_reg, 148 }; 149 150 static irqreturn_t cap11xx_thread_func(int irq_num, void *data) 151 { 152 struct cap11xx_priv *priv = data; 153 unsigned int status; 154 int ret, i; 155 156 /* 157 * Deassert interrupt. This needs to be done before reading the status 158 * registers, which will not carry valid values otherwise. 159 */ 160 ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0); 161 if (ret < 0) 162 goto out; 163 164 ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status); 165 if (ret < 0) 166 goto out; 167 168 for (i = 0; i < priv->idev->keycodemax; i++) 169 input_report_key(priv->idev, priv->keycodes[i], 170 status & (1 << i)); 171 172 input_sync(priv->idev); 173 174 out: 175 return IRQ_HANDLED; 176 } 177 178 static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep) 179 { 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); 183 } 184 185 static int cap11xx_input_open(struct input_dev *idev) 186 { 187 struct cap11xx_priv *priv = input_get_drvdata(idev); 188 189 return cap11xx_set_sleep(priv, false); 190 } 191 192 static void cap11xx_input_close(struct input_dev *idev) 193 { 194 struct cap11xx_priv *priv = input_get_drvdata(idev); 195 196 cap11xx_set_sleep(priv, true); 197 } 198 199 static int cap11xx_i2c_probe(struct i2c_client *i2c_client, 200 const struct i2c_device_id *id) 201 { 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; 208 u32 gain32; 209 210 if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) { 211 dev_err(dev, "Invalid device ID %lu\n", id->driver_data); 212 return -EINVAL; 213 } 214 215 cap = &cap11xx_devices[id->driver_data]; 216 if (!cap || !cap->num_channels) { 217 dev_err(dev, "Invalid device configuration\n"); 218 return -EINVAL; 219 } 220 221 priv = devm_kzalloc(dev, 222 sizeof(*priv) + 223 cap->num_channels * sizeof(priv->keycodes[0]), 224 GFP_KERNEL); 225 if (!priv) 226 return -ENOMEM; 227 228 priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config); 229 if (IS_ERR(priv->regmap)) 230 return PTR_ERR(priv->regmap); 231 232 error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val); 233 if (error) 234 return error; 235 236 if (val != cap->product_id) { 237 dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n", 238 val, cap->product_id); 239 return -ENXIO; 240 } 241 242 error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val); 243 if (error) 244 return error; 245 246 if (val != CAP11XX_MANUFACTURER_ID) { 247 dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n", 248 val, CAP11XX_MANUFACTURER_ID); 249 return -ENXIO; 250 } 251 252 error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev); 253 if (error < 0) 254 return error; 255 256 dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev); 257 i2c_set_clientdata(i2c_client, priv); 258 node = dev->of_node; 259 260 if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) { 261 if (is_power_of_2(gain32) && gain32 <= 8) 262 gain = ilog2(gain32); 263 else 264 dev_err(dev, "Invalid sensor-gain value %d\n", gain32); 265 } 266 267 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); 270 if (error) 271 return error; 272 } 273 274 /* Provide some useful defaults */ 275 for (i = 0; i < cap->num_channels; i++) 276 priv->keycodes[i] = KEY_A + i; 277 278 of_property_read_u32_array(node, "linux,keycodes", 279 priv->keycodes, cap->num_channels); 280 281 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); 284 if (error) 285 return error; 286 287 /* Disable autorepeat. The Linux input system has its own handling. */ 288 error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0); 289 if (error) 290 return error; 291 292 priv->idev = devm_input_allocate_device(dev); 293 if (!priv->idev) 294 return -ENOMEM; 295 296 priv->idev->name = "CAP11XX capacitive touch sensor"; 297 priv->idev->id.bustype = BUS_I2C; 298 priv->idev->evbit[0] = BIT_MASK(EV_KEY); 299 300 if (of_property_read_bool(node, "autorepeat")) 301 __set_bit(EV_REP, priv->idev->evbit); 302 303 for (i = 0; i < cap->num_channels; i++) 304 __set_bit(priv->keycodes[i], priv->idev->keybit); 305 306 __clear_bit(KEY_RESERVED, priv->idev->keybit); 307 308 priv->idev->keycode = priv->keycodes; 309 priv->idev->keycodesize = sizeof(priv->keycodes[0]); 310 priv->idev->keycodemax = cap->num_channels; 311 312 priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID; 313 priv->idev->id.product = cap->product_id; 314 priv->idev->id.version = rev; 315 316 priv->idev->open = cap11xx_input_open; 317 priv->idev->close = cap11xx_input_close; 318 319 input_set_drvdata(priv->idev, priv); 320 321 /* 322 * Put the device in deep sleep mode for now. 323 * ->open() will bring it back once the it is actually needed. 324 */ 325 cap11xx_set_sleep(priv, true); 326 327 error = input_register_device(priv->idev); 328 if (error) 329 return error; 330 331 irq = irq_of_parse_and_map(node, 0); 332 if (!irq) { 333 dev_err(dev, "Unable to parse or map IRQ\n"); 334 return -ENXIO; 335 } 336 337 error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func, 338 IRQF_ONESHOT, dev_name(dev), priv); 339 if (error) 340 return error; 341 342 return 0; 343 } 344 345 static const struct of_device_id cap11xx_dt_ids[] = { 346 { .compatible = "microchip,cap1106", }, 347 { .compatible = "microchip,cap1126", }, 348 { .compatible = "microchip,cap1188", }, 349 {} 350 }; 351 MODULE_DEVICE_TABLE(of, cap11xx_dt_ids); 352 353 static const struct i2c_device_id cap11xx_i2c_ids[] = { 354 { "cap1106", CAP1106 }, 355 { "cap1126", CAP1126 }, 356 { "cap1188", CAP1188 }, 357 {} 358 }; 359 MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids); 360 361 static struct i2c_driver cap11xx_i2c_driver = { 362 .driver = { 363 .name = "cap11xx", 364 .owner = THIS_MODULE, 365 .of_match_table = cap11xx_dt_ids, 366 }, 367 .id_table = cap11xx_i2c_ids, 368 .probe = cap11xx_i2c_probe, 369 }; 370 371 module_i2c_driver(cap11xx_i2c_driver); 372 373 MODULE_ALIAS("platform:cap11xx"); 374 MODULE_DESCRIPTION("Microchip CAP11XX driver"); 375 MODULE_AUTHOR("Daniel Mack <linux@zonque.org>"); 376 MODULE_LICENSE("GPL v2"); 377