1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Touchkey driver for Freescale MPR121 Controllor 4 * 5 * Copyright (C) 2011 Freescale Semiconductor, Inc. 6 * Author: Zhang Jiejing <jiejing.zhang@freescale.com> 7 * 8 * Based on mcs_touchkey.c 9 */ 10 11 #include <linux/bitops.h> 12 #include <linux/delay.h> 13 #include <linux/i2c.h> 14 #include <linux/input.h> 15 #include <linux/interrupt.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/property.h> 19 #include <linux/regulator/consumer.h> 20 #include <linux/slab.h> 21 22 /* Register definitions */ 23 #define ELE_TOUCH_STATUS_0_ADDR 0x0 24 #define ELE_TOUCH_STATUS_1_ADDR 0X1 25 #define MHD_RISING_ADDR 0x2b 26 #define NHD_RISING_ADDR 0x2c 27 #define NCL_RISING_ADDR 0x2d 28 #define FDL_RISING_ADDR 0x2e 29 #define MHD_FALLING_ADDR 0x2f 30 #define NHD_FALLING_ADDR 0x30 31 #define NCL_FALLING_ADDR 0x31 32 #define FDL_FALLING_ADDR 0x32 33 #define ELE0_TOUCH_THRESHOLD_ADDR 0x41 34 #define ELE0_RELEASE_THRESHOLD_ADDR 0x42 35 #define AFE_CONF_ADDR 0x5c 36 #define FILTER_CONF_ADDR 0x5d 37 38 /* 39 * ELECTRODE_CONF_ADDR: This register configures the number of 40 * enabled capacitance sensing inputs and its run/suspend mode. 41 */ 42 #define ELECTRODE_CONF_ADDR 0x5e 43 #define ELECTRODE_CONF_QUICK_CHARGE 0x80 44 #define AUTO_CONFIG_CTRL_ADDR 0x7b 45 #define AUTO_CONFIG_USL_ADDR 0x7d 46 #define AUTO_CONFIG_LSL_ADDR 0x7e 47 #define AUTO_CONFIG_TL_ADDR 0x7f 48 49 /* Threshold of touch/release trigger */ 50 #define TOUCH_THRESHOLD 0x08 51 #define RELEASE_THRESHOLD 0x05 52 /* Masks for touch and release triggers */ 53 #define TOUCH_STATUS_MASK 0xfff 54 /* MPR121 has 12 keys */ 55 #define MPR121_MAX_KEY_COUNT 12 56 57 struct mpr121_touchkey { 58 struct i2c_client *client; 59 struct input_dev *input_dev; 60 unsigned int statusbits; 61 unsigned int keycount; 62 u32 keycodes[MPR121_MAX_KEY_COUNT]; 63 }; 64 65 struct mpr121_init_register { 66 int addr; 67 u8 val; 68 }; 69 70 static const struct mpr121_init_register init_reg_table[] = { 71 { MHD_RISING_ADDR, 0x1 }, 72 { NHD_RISING_ADDR, 0x1 }, 73 { MHD_FALLING_ADDR, 0x1 }, 74 { NHD_FALLING_ADDR, 0x1 }, 75 { NCL_FALLING_ADDR, 0xff }, 76 { FDL_FALLING_ADDR, 0x02 }, 77 { FILTER_CONF_ADDR, 0x04 }, 78 { AFE_CONF_ADDR, 0x0b }, 79 { AUTO_CONFIG_CTRL_ADDR, 0x0b }, 80 }; 81 82 static void mpr121_vdd_supply_disable(void *data) 83 { 84 struct regulator *vdd_supply = data; 85 86 regulator_disable(vdd_supply); 87 } 88 89 static struct regulator *mpr121_vdd_supply_init(struct device *dev) 90 { 91 struct regulator *vdd_supply; 92 int err; 93 94 vdd_supply = devm_regulator_get(dev, "vdd"); 95 if (IS_ERR(vdd_supply)) { 96 dev_err(dev, "failed to get vdd regulator: %ld\n", 97 PTR_ERR(vdd_supply)); 98 return vdd_supply; 99 } 100 101 err = regulator_enable(vdd_supply); 102 if (err) { 103 dev_err(dev, "failed to enable vdd regulator: %d\n", err); 104 return ERR_PTR(err); 105 } 106 107 err = devm_add_action(dev, mpr121_vdd_supply_disable, vdd_supply); 108 if (err) { 109 regulator_disable(vdd_supply); 110 dev_err(dev, "failed to add disable regulator action: %d\n", 111 err); 112 return ERR_PTR(err); 113 } 114 115 return vdd_supply; 116 } 117 118 static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id) 119 { 120 struct mpr121_touchkey *mpr121 = dev_id; 121 struct i2c_client *client = mpr121->client; 122 struct input_dev *input = mpr121->input_dev; 123 unsigned long bit_changed; 124 unsigned int key_num; 125 int reg; 126 127 reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR); 128 if (reg < 0) { 129 dev_err(&client->dev, "i2c read error [%d]\n", reg); 130 goto out; 131 } 132 133 reg <<= 8; 134 reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR); 135 if (reg < 0) { 136 dev_err(&client->dev, "i2c read error [%d]\n", reg); 137 goto out; 138 } 139 140 reg &= TOUCH_STATUS_MASK; 141 /* use old press bit to figure out which bit changed */ 142 bit_changed = reg ^ mpr121->statusbits; 143 mpr121->statusbits = reg; 144 for_each_set_bit(key_num, &bit_changed, mpr121->keycount) { 145 unsigned int key_val, pressed; 146 147 pressed = reg & BIT(key_num); 148 key_val = mpr121->keycodes[key_num]; 149 150 input_event(input, EV_MSC, MSC_SCAN, key_num); 151 input_report_key(input, key_val, pressed); 152 153 dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val, 154 pressed ? "pressed" : "released"); 155 156 } 157 input_sync(input); 158 159 out: 160 return IRQ_HANDLED; 161 } 162 163 static int mpr121_phys_init(struct mpr121_touchkey *mpr121, 164 struct i2c_client *client, int vdd_uv) 165 { 166 const struct mpr121_init_register *reg; 167 unsigned char usl, lsl, tl, eleconf; 168 int i, t, vdd, ret; 169 170 /* Set up touch/release threshold for ele0-ele11 */ 171 for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) { 172 t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2); 173 ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD); 174 if (ret < 0) 175 goto err_i2c_write; 176 ret = i2c_smbus_write_byte_data(client, t + 1, 177 RELEASE_THRESHOLD); 178 if (ret < 0) 179 goto err_i2c_write; 180 } 181 182 /* Set up init register */ 183 for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) { 184 reg = &init_reg_table[i]; 185 ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val); 186 if (ret < 0) 187 goto err_i2c_write; 188 } 189 190 191 /* 192 * Capacitance on sensing input varies and needs to be compensated. 193 * The internal MPR121-auto-configuration can do this if it's 194 * registers are set properly (based on vdd_uv). 195 */ 196 vdd = vdd_uv / 1000; 197 usl = ((vdd - 700) * 256) / vdd; 198 lsl = (usl * 65) / 100; 199 tl = (usl * 90) / 100; 200 ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl); 201 ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl); 202 ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl); 203 204 /* 205 * Quick charge bit will let the capacitive charge to ready 206 * state quickly, or the buttons may not function after system 207 * boot. 208 */ 209 eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE; 210 ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 211 eleconf); 212 if (ret != 0) 213 goto err_i2c_write; 214 215 dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount); 216 217 return 0; 218 219 err_i2c_write: 220 dev_err(&client->dev, "i2c write error: %d\n", ret); 221 return ret; 222 } 223 224 static int mpr_touchkey_probe(struct i2c_client *client, 225 const struct i2c_device_id *id) 226 { 227 struct device *dev = &client->dev; 228 struct regulator *vdd_supply; 229 int vdd_uv; 230 struct mpr121_touchkey *mpr121; 231 struct input_dev *input_dev; 232 int error; 233 int i; 234 235 if (!client->irq) { 236 dev_err(dev, "irq number should not be zero\n"); 237 return -EINVAL; 238 } 239 240 vdd_supply = mpr121_vdd_supply_init(dev); 241 if (IS_ERR(vdd_supply)) 242 return PTR_ERR(vdd_supply); 243 244 vdd_uv = regulator_get_voltage(vdd_supply); 245 246 mpr121 = devm_kzalloc(dev, sizeof(*mpr121), GFP_KERNEL); 247 if (!mpr121) 248 return -ENOMEM; 249 250 input_dev = devm_input_allocate_device(dev); 251 if (!input_dev) 252 return -ENOMEM; 253 254 mpr121->client = client; 255 mpr121->input_dev = input_dev; 256 mpr121->keycount = device_property_read_u32_array(dev, "linux,keycodes", 257 NULL, 0); 258 if (mpr121->keycount > MPR121_MAX_KEY_COUNT) { 259 dev_err(dev, "too many keys defined (%d)\n", mpr121->keycount); 260 return -EINVAL; 261 } 262 263 error = device_property_read_u32_array(dev, "linux,keycodes", 264 mpr121->keycodes, 265 mpr121->keycount); 266 if (error) { 267 dev_err(dev, 268 "failed to read linux,keycode property: %d\n", error); 269 return error; 270 } 271 272 input_dev->name = "Freescale MPR121 Touchkey"; 273 input_dev->id.bustype = BUS_I2C; 274 input_dev->dev.parent = dev; 275 if (device_property_read_bool(dev, "autorepeat")) 276 __set_bit(EV_REP, input_dev->evbit); 277 input_set_capability(input_dev, EV_MSC, MSC_SCAN); 278 279 input_dev->keycode = mpr121->keycodes; 280 input_dev->keycodesize = sizeof(mpr121->keycodes[0]); 281 input_dev->keycodemax = mpr121->keycount; 282 283 for (i = 0; i < mpr121->keycount; i++) 284 input_set_capability(input_dev, EV_KEY, mpr121->keycodes[i]); 285 286 error = mpr121_phys_init(mpr121, client, vdd_uv); 287 if (error) { 288 dev_err(dev, "Failed to init register\n"); 289 return error; 290 } 291 292 error = devm_request_threaded_irq(dev, client->irq, NULL, 293 mpr_touchkey_interrupt, 294 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 295 dev->driver->name, mpr121); 296 if (error) { 297 dev_err(dev, "Failed to register interrupt\n"); 298 return error; 299 } 300 301 error = input_register_device(input_dev); 302 if (error) 303 return error; 304 305 i2c_set_clientdata(client, mpr121); 306 device_init_wakeup(dev, 307 device_property_read_bool(dev, "wakeup-source")); 308 309 return 0; 310 } 311 312 static int __maybe_unused mpr_suspend(struct device *dev) 313 { 314 struct i2c_client *client = to_i2c_client(dev); 315 316 if (device_may_wakeup(&client->dev)) 317 enable_irq_wake(client->irq); 318 319 i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00); 320 321 return 0; 322 } 323 324 static int __maybe_unused mpr_resume(struct device *dev) 325 { 326 struct i2c_client *client = to_i2c_client(dev); 327 struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); 328 329 if (device_may_wakeup(&client->dev)) 330 disable_irq_wake(client->irq); 331 332 i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 333 mpr121->keycount); 334 335 return 0; 336 } 337 338 static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume); 339 340 static const struct i2c_device_id mpr121_id[] = { 341 { "mpr121_touchkey", 0 }, 342 { } 343 }; 344 MODULE_DEVICE_TABLE(i2c, mpr121_id); 345 346 #ifdef CONFIG_OF 347 static const struct of_device_id mpr121_touchkey_dt_match_table[] = { 348 { .compatible = "fsl,mpr121-touchkey" }, 349 { }, 350 }; 351 MODULE_DEVICE_TABLE(of, mpr121_touchkey_dt_match_table); 352 #endif 353 354 static struct i2c_driver mpr_touchkey_driver = { 355 .driver = { 356 .name = "mpr121", 357 .pm = &mpr121_touchkey_pm_ops, 358 .of_match_table = of_match_ptr(mpr121_touchkey_dt_match_table), 359 }, 360 .id_table = mpr121_id, 361 .probe = mpr_touchkey_probe, 362 }; 363 364 module_i2c_driver(mpr_touchkey_driver); 365 366 MODULE_LICENSE("GPL"); 367 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); 368 MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip"); 369