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 #define MPR121_MIN_POLL_INTERVAL 10 58 #define MPR121_MAX_POLL_INTERVAL 200 59 60 struct mpr121_touchkey { 61 struct i2c_client *client; 62 struct input_dev *input_dev; 63 unsigned int statusbits; 64 unsigned int keycount; 65 u32 keycodes[MPR121_MAX_KEY_COUNT]; 66 }; 67 68 struct mpr121_init_register { 69 int addr; 70 u8 val; 71 }; 72 73 static const struct mpr121_init_register init_reg_table[] = { 74 { MHD_RISING_ADDR, 0x1 }, 75 { NHD_RISING_ADDR, 0x1 }, 76 { MHD_FALLING_ADDR, 0x1 }, 77 { NHD_FALLING_ADDR, 0x1 }, 78 { NCL_FALLING_ADDR, 0xff }, 79 { FDL_FALLING_ADDR, 0x02 }, 80 { FILTER_CONF_ADDR, 0x04 }, 81 { AFE_CONF_ADDR, 0x0b }, 82 { AUTO_CONFIG_CTRL_ADDR, 0x0b }, 83 }; 84 85 static void mpr_touchkey_report(struct input_dev *dev) 86 { 87 struct mpr121_touchkey *mpr121 = input_get_drvdata(dev); 88 struct input_dev *input = mpr121->input_dev; 89 struct i2c_client *client = mpr121->client; 90 unsigned long bit_changed; 91 unsigned int key_num; 92 int reg; 93 94 reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR); 95 if (reg < 0) { 96 dev_err(&client->dev, "i2c read error [%d]\n", reg); 97 return; 98 } 99 100 reg <<= 8; 101 reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR); 102 if (reg < 0) { 103 dev_err(&client->dev, "i2c read error [%d]\n", reg); 104 return; 105 } 106 107 reg &= TOUCH_STATUS_MASK; 108 /* use old press bit to figure out which bit changed */ 109 bit_changed = reg ^ mpr121->statusbits; 110 mpr121->statusbits = reg; 111 for_each_set_bit(key_num, &bit_changed, mpr121->keycount) { 112 unsigned int key_val, pressed; 113 114 pressed = reg & BIT(key_num); 115 key_val = mpr121->keycodes[key_num]; 116 117 input_event(input, EV_MSC, MSC_SCAN, key_num); 118 input_report_key(input, key_val, pressed); 119 120 dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val, 121 pressed ? "pressed" : "released"); 122 123 } 124 input_sync(input); 125 } 126 127 static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id) 128 { 129 struct mpr121_touchkey *mpr121 = dev_id; 130 131 mpr_touchkey_report(mpr121->input_dev); 132 133 return IRQ_HANDLED; 134 } 135 136 static int mpr121_phys_init(struct mpr121_touchkey *mpr121, 137 struct i2c_client *client, int vdd_uv) 138 { 139 const struct mpr121_init_register *reg; 140 unsigned char usl, lsl, tl, eleconf; 141 int i, t, vdd, ret; 142 143 /* Set up touch/release threshold for ele0-ele11 */ 144 for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) { 145 t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2); 146 ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD); 147 if (ret < 0) 148 goto err_i2c_write; 149 ret = i2c_smbus_write_byte_data(client, t + 1, 150 RELEASE_THRESHOLD); 151 if (ret < 0) 152 goto err_i2c_write; 153 } 154 155 /* Set up init register */ 156 for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) { 157 reg = &init_reg_table[i]; 158 ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val); 159 if (ret < 0) 160 goto err_i2c_write; 161 } 162 163 164 /* 165 * Capacitance on sensing input varies and needs to be compensated. 166 * The internal MPR121-auto-configuration can do this if it's 167 * registers are set properly (based on vdd_uv). 168 */ 169 vdd = vdd_uv / 1000; 170 usl = ((vdd - 700) * 256) / vdd; 171 lsl = (usl * 65) / 100; 172 tl = (usl * 90) / 100; 173 ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl); 174 ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl); 175 ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl); 176 177 /* 178 * Quick charge bit will let the capacitive charge to ready 179 * state quickly, or the buttons may not function after system 180 * boot. 181 */ 182 eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE; 183 ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 184 eleconf); 185 if (ret != 0) 186 goto err_i2c_write; 187 188 dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount); 189 190 return 0; 191 192 err_i2c_write: 193 dev_err(&client->dev, "i2c write error: %d\n", ret); 194 return ret; 195 } 196 197 static int mpr_touchkey_probe(struct i2c_client *client) 198 { 199 struct device *dev = &client->dev; 200 int vdd_uv; 201 struct mpr121_touchkey *mpr121; 202 struct input_dev *input_dev; 203 u32 poll_interval = 0; 204 int error; 205 int i; 206 207 vdd_uv = devm_regulator_get_enable_read_voltage(dev, "vdd"); 208 if (vdd_uv < 0) 209 return dev_err_probe(dev, vdd_uv, "failed to get vdd voltage\n"); 210 211 mpr121 = devm_kzalloc(dev, sizeof(*mpr121), GFP_KERNEL); 212 if (!mpr121) 213 return -ENOMEM; 214 215 input_dev = devm_input_allocate_device(dev); 216 if (!input_dev) 217 return -ENOMEM; 218 219 mpr121->client = client; 220 mpr121->input_dev = input_dev; 221 mpr121->keycount = device_property_count_u32(dev, "linux,keycodes"); 222 if (mpr121->keycount > MPR121_MAX_KEY_COUNT) { 223 dev_err(dev, "too many keys defined (%d)\n", mpr121->keycount); 224 return -EINVAL; 225 } 226 227 error = device_property_read_u32_array(dev, "linux,keycodes", 228 mpr121->keycodes, 229 mpr121->keycount); 230 if (error) { 231 dev_err(dev, 232 "failed to read linux,keycode property: %d\n", error); 233 return error; 234 } 235 236 input_dev->name = "Freescale MPR121 Touchkey"; 237 input_dev->id.bustype = BUS_I2C; 238 input_dev->dev.parent = dev; 239 if (device_property_read_bool(dev, "autorepeat")) 240 __set_bit(EV_REP, input_dev->evbit); 241 input_set_capability(input_dev, EV_MSC, MSC_SCAN); 242 input_set_drvdata(input_dev, mpr121); 243 244 input_dev->keycode = mpr121->keycodes; 245 input_dev->keycodesize = sizeof(mpr121->keycodes[0]); 246 input_dev->keycodemax = mpr121->keycount; 247 248 for (i = 0; i < mpr121->keycount; i++) 249 input_set_capability(input_dev, EV_KEY, mpr121->keycodes[i]); 250 251 error = mpr121_phys_init(mpr121, client, vdd_uv); 252 if (error) { 253 dev_err(dev, "Failed to init register\n"); 254 return error; 255 } 256 257 device_property_read_u32(dev, "poll-interval", &poll_interval); 258 259 if (client->irq) { 260 error = devm_request_threaded_irq(dev, client->irq, NULL, 261 mpr_touchkey_interrupt, 262 IRQF_TRIGGER_FALLING | 263 IRQF_ONESHOT, 264 dev->driver->name, mpr121); 265 if (error) { 266 dev_err(dev, "Failed to register interrupt\n"); 267 return error; 268 } 269 } else if (poll_interval) { 270 if (poll_interval < MPR121_MIN_POLL_INTERVAL) 271 return -EINVAL; 272 273 if (poll_interval > MPR121_MAX_POLL_INTERVAL) 274 return -EINVAL; 275 276 error = input_setup_polling(input_dev, mpr_touchkey_report); 277 if (error) { 278 dev_err(dev, "Failed to setup polling\n"); 279 return error; 280 } 281 282 input_set_poll_interval(input_dev, poll_interval); 283 input_set_min_poll_interval(input_dev, 284 MPR121_MIN_POLL_INTERVAL); 285 input_set_max_poll_interval(input_dev, 286 MPR121_MAX_POLL_INTERVAL); 287 } else { 288 dev_err(dev, 289 "invalid IRQ number and polling not configured\n"); 290 return -EINVAL; 291 } 292 293 error = input_register_device(input_dev); 294 if (error) 295 return error; 296 297 i2c_set_clientdata(client, mpr121); 298 device_init_wakeup(dev, 299 device_property_read_bool(dev, "wakeup-source")); 300 301 return 0; 302 } 303 304 static int mpr_suspend(struct device *dev) 305 { 306 struct i2c_client *client = to_i2c_client(dev); 307 308 if (device_may_wakeup(&client->dev)) 309 enable_irq_wake(client->irq); 310 311 i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00); 312 313 return 0; 314 } 315 316 static int mpr_resume(struct device *dev) 317 { 318 struct i2c_client *client = to_i2c_client(dev); 319 struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); 320 321 if (device_may_wakeup(&client->dev)) 322 disable_irq_wake(client->irq); 323 324 i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 325 mpr121->keycount); 326 327 return 0; 328 } 329 330 static DEFINE_SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume); 331 332 static const struct i2c_device_id mpr121_id[] = { 333 { "mpr121_touchkey" }, 334 { } 335 }; 336 MODULE_DEVICE_TABLE(i2c, mpr121_id); 337 338 #ifdef CONFIG_OF 339 static const struct of_device_id mpr121_touchkey_dt_match_table[] = { 340 { .compatible = "fsl,mpr121-touchkey" }, 341 { }, 342 }; 343 MODULE_DEVICE_TABLE(of, mpr121_touchkey_dt_match_table); 344 #endif 345 346 static struct i2c_driver mpr_touchkey_driver = { 347 .driver = { 348 .name = "mpr121", 349 .pm = pm_sleep_ptr(&mpr121_touchkey_pm_ops), 350 .of_match_table = of_match_ptr(mpr121_touchkey_dt_match_table), 351 }, 352 .id_table = mpr121_id, 353 .probe = mpr_touchkey_probe, 354 }; 355 356 module_i2c_driver(mpr_touchkey_driver); 357 358 MODULE_LICENSE("GPL"); 359 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); 360 MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip"); 361