Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Touchkey driver for Freescale MPR121 Controllor |
| 3 | * |
| 4 | * Copyright (C) 2011 Freescale Semiconductor, Inc. |
| 5 | * Author: Zhang Jiejing <jiejing.zhang@freescale.com> |
| 6 | * |
| 7 | * Based on mcs_touchkey.c |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | * |
| 13 | */ |
| 14 | |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/input.h> |
| 18 | #include <linux/i2c.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/delay.h> |
| 21 | #include <linux/bitops.h> |
| 22 | #include <linux/interrupt.h> |
| 23 | #include <linux/i2c/mpr121_touchkey.h> |
| 24 | |
| 25 | /* Register definitions */ |
| 26 | #define ELE_TOUCH_STATUS_0_ADDR 0x0 |
| 27 | #define ELE_TOUCH_STATUS_1_ADDR 0X1 |
| 28 | #define MHD_RISING_ADDR 0x2b |
| 29 | #define NHD_RISING_ADDR 0x2c |
| 30 | #define NCL_RISING_ADDR 0x2d |
| 31 | #define FDL_RISING_ADDR 0x2e |
| 32 | #define MHD_FALLING_ADDR 0x2f |
| 33 | #define NHD_FALLING_ADDR 0x30 |
| 34 | #define NCL_FALLING_ADDR 0x31 |
| 35 | #define FDL_FALLING_ADDR 0x32 |
| 36 | #define ELE0_TOUCH_THRESHOLD_ADDR 0x41 |
| 37 | #define ELE0_RELEASE_THRESHOLD_ADDR 0x42 |
| 38 | #define AFE_CONF_ADDR 0x5c |
| 39 | #define FILTER_CONF_ADDR 0x5d |
| 40 | |
| 41 | /* |
| 42 | * ELECTRODE_CONF_ADDR: This register configures the number of |
| 43 | * enabled capacitance sensing inputs and its run/suspend mode. |
| 44 | */ |
| 45 | #define ELECTRODE_CONF_ADDR 0x5e |
Jiejing Zhang | c7b4a5d | 2011-06-29 01:28:21 -0700 | [diff] [blame] | 46 | #define ELECTRODE_CONF_QUICK_CHARGE 0x80 |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 47 | #define AUTO_CONFIG_CTRL_ADDR 0x7b |
| 48 | #define AUTO_CONFIG_USL_ADDR 0x7d |
| 49 | #define AUTO_CONFIG_LSL_ADDR 0x7e |
| 50 | #define AUTO_CONFIG_TL_ADDR 0x7f |
| 51 | |
| 52 | /* Threshold of touch/release trigger */ |
Jiejing Zhang | c7b4a5d | 2011-06-29 01:28:21 -0700 | [diff] [blame] | 53 | #define TOUCH_THRESHOLD 0x08 |
| 54 | #define RELEASE_THRESHOLD 0x05 |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 55 | /* Masks for touch and release triggers */ |
| 56 | #define TOUCH_STATUS_MASK 0xfff |
| 57 | /* MPR121 has 12 keys */ |
| 58 | #define MPR121_MAX_KEY_COUNT 12 |
| 59 | |
| 60 | struct mpr121_touchkey { |
| 61 | struct i2c_client *client; |
| 62 | struct input_dev *input_dev; |
| 63 | unsigned int key_val; |
| 64 | unsigned int statusbits; |
| 65 | unsigned int keycount; |
| 66 | u16 keycodes[MPR121_MAX_KEY_COUNT]; |
| 67 | }; |
| 68 | |
| 69 | struct mpr121_init_register { |
| 70 | int addr; |
| 71 | u8 val; |
| 72 | }; |
| 73 | |
| 74 | static const struct mpr121_init_register init_reg_table[] __devinitconst = { |
| 75 | { MHD_RISING_ADDR, 0x1 }, |
| 76 | { NHD_RISING_ADDR, 0x1 }, |
| 77 | { MHD_FALLING_ADDR, 0x1 }, |
| 78 | { NHD_FALLING_ADDR, 0x1 }, |
| 79 | { NCL_FALLING_ADDR, 0xff }, |
| 80 | { FDL_FALLING_ADDR, 0x02 }, |
| 81 | { FILTER_CONF_ADDR, 0x04 }, |
| 82 | { AFE_CONF_ADDR, 0x0b }, |
| 83 | { AUTO_CONFIG_CTRL_ADDR, 0x0b }, |
| 84 | }; |
| 85 | |
| 86 | static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id) |
| 87 | { |
| 88 | struct mpr121_touchkey *mpr121 = dev_id; |
| 89 | struct i2c_client *client = mpr121->client; |
| 90 | struct input_dev *input = mpr121->input_dev; |
| 91 | unsigned int key_num, key_val, pressed; |
| 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 | goto out; |
| 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 | goto out; |
| 105 | } |
| 106 | |
| 107 | reg &= TOUCH_STATUS_MASK; |
| 108 | /* use old press bit to figure out which bit changed */ |
| 109 | key_num = ffs(reg ^ mpr121->statusbits) - 1; |
| 110 | pressed = reg & (1 << key_num); |
| 111 | mpr121->statusbits = reg; |
| 112 | |
| 113 | key_val = mpr121->keycodes[key_num]; |
| 114 | |
| 115 | input_event(input, EV_MSC, MSC_SCAN, key_num); |
| 116 | input_report_key(input, key_val, pressed); |
| 117 | input_sync(input); |
| 118 | |
| 119 | dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val, |
| 120 | pressed ? "pressed" : "released"); |
| 121 | |
| 122 | out: |
| 123 | return IRQ_HANDLED; |
| 124 | } |
| 125 | |
| 126 | static int __devinit mpr121_phys_init(const struct mpr121_platform_data *pdata, |
| 127 | struct mpr121_touchkey *mpr121, |
| 128 | struct i2c_client *client) |
| 129 | { |
| 130 | const struct mpr121_init_register *reg; |
Jiejing Zhang | c7b4a5d | 2011-06-29 01:28:21 -0700 | [diff] [blame] | 131 | unsigned char usl, lsl, tl, eleconf; |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 132 | int i, t, vdd, ret; |
| 133 | |
| 134 | /* Set up touch/release threshold for ele0-ele11 */ |
| 135 | for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) { |
| 136 | t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2); |
| 137 | ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD); |
| 138 | if (ret < 0) |
| 139 | goto err_i2c_write; |
| 140 | ret = i2c_smbus_write_byte_data(client, t + 1, |
| 141 | RELEASE_THRESHOLD); |
| 142 | if (ret < 0) |
| 143 | goto err_i2c_write; |
| 144 | } |
| 145 | |
| 146 | /* Set up init register */ |
| 147 | for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) { |
| 148 | reg = &init_reg_table[i]; |
| 149 | ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val); |
| 150 | if (ret < 0) |
| 151 | goto err_i2c_write; |
| 152 | } |
| 153 | |
| 154 | |
| 155 | /* |
| 156 | * Capacitance on sensing input varies and needs to be compensated. |
| 157 | * The internal MPR121-auto-configuration can do this if it's |
| 158 | * registers are set properly (based on pdata->vdd_uv). |
| 159 | */ |
| 160 | vdd = pdata->vdd_uv / 1000; |
| 161 | usl = ((vdd - 700) * 256) / vdd; |
| 162 | lsl = (usl * 65) / 100; |
| 163 | tl = (usl * 90) / 100; |
| 164 | ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl); |
| 165 | ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl); |
| 166 | ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl); |
Jiejing Zhang | c7b4a5d | 2011-06-29 01:28:21 -0700 | [diff] [blame] | 167 | |
| 168 | /* |
| 169 | * Quick charge bit will let the capacitive charge to ready |
| 170 | * state quickly, or the buttons may not function after system |
| 171 | * boot. |
| 172 | */ |
| 173 | eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE; |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 174 | ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, |
Jiejing Zhang | c7b4a5d | 2011-06-29 01:28:21 -0700 | [diff] [blame] | 175 | eleconf); |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 176 | if (ret != 0) |
| 177 | goto err_i2c_write; |
| 178 | |
| 179 | dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount); |
| 180 | |
| 181 | return 0; |
| 182 | |
| 183 | err_i2c_write: |
| 184 | dev_err(&client->dev, "i2c write error: %d\n", ret); |
| 185 | return ret; |
| 186 | } |
| 187 | |
| 188 | static int __devinit mpr_touchkey_probe(struct i2c_client *client, |
| 189 | const struct i2c_device_id *id) |
| 190 | { |
| 191 | const struct mpr121_platform_data *pdata = client->dev.platform_data; |
| 192 | struct mpr121_touchkey *mpr121; |
| 193 | struct input_dev *input_dev; |
| 194 | int error; |
| 195 | int i; |
| 196 | |
| 197 | if (!pdata) { |
| 198 | dev_err(&client->dev, "no platform data defined\n"); |
| 199 | return -EINVAL; |
| 200 | } |
| 201 | |
| 202 | if (!pdata->keymap || !pdata->keymap_size) { |
| 203 | dev_err(&client->dev, "missing keymap data\n"); |
| 204 | return -EINVAL; |
| 205 | } |
| 206 | |
| 207 | if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) { |
| 208 | dev_err(&client->dev, "too many keys defined\n"); |
| 209 | return -EINVAL; |
| 210 | } |
| 211 | |
| 212 | if (!client->irq) { |
| 213 | dev_err(&client->dev, "irq number should not be zero\n"); |
| 214 | return -EINVAL; |
| 215 | } |
| 216 | |
| 217 | mpr121 = kzalloc(sizeof(struct mpr121_touchkey), GFP_KERNEL); |
| 218 | input_dev = input_allocate_device(); |
| 219 | if (!mpr121 || !input_dev) { |
| 220 | dev_err(&client->dev, "Failed to allocate memory\n"); |
| 221 | error = -ENOMEM; |
| 222 | goto err_free_mem; |
| 223 | } |
| 224 | |
| 225 | mpr121->client = client; |
| 226 | mpr121->input_dev = input_dev; |
| 227 | mpr121->keycount = pdata->keymap_size; |
| 228 | |
| 229 | input_dev->name = "Freescale MPR121 Touchkey"; |
| 230 | input_dev->id.bustype = BUS_I2C; |
| 231 | input_dev->dev.parent = &client->dev; |
| 232 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); |
| 233 | |
| 234 | input_dev->keycode = mpr121->keycodes; |
| 235 | input_dev->keycodesize = sizeof(mpr121->keycodes[0]); |
| 236 | input_dev->keycodemax = mpr121->keycount; |
| 237 | |
| 238 | for (i = 0; i < pdata->keymap_size; i++) { |
| 239 | input_set_capability(input_dev, EV_KEY, pdata->keymap[i]); |
| 240 | mpr121->keycodes[i] = pdata->keymap[i]; |
| 241 | } |
| 242 | |
| 243 | error = mpr121_phys_init(pdata, mpr121, client); |
| 244 | if (error) { |
| 245 | dev_err(&client->dev, "Failed to init register\n"); |
| 246 | goto err_free_mem; |
| 247 | } |
| 248 | |
| 249 | error = request_threaded_irq(client->irq, NULL, |
| 250 | mpr_touchkey_interrupt, |
Lars-Peter Clausen | 9b7e31b | 2012-07-04 13:02:56 -0700 | [diff] [blame] | 251 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 252 | client->dev.driver->name, mpr121); |
| 253 | if (error) { |
| 254 | dev_err(&client->dev, "Failed to register interrupt\n"); |
| 255 | goto err_free_mem; |
| 256 | } |
| 257 | |
| 258 | error = input_register_device(input_dev); |
| 259 | if (error) |
| 260 | goto err_free_irq; |
| 261 | |
| 262 | i2c_set_clientdata(client, mpr121); |
| 263 | device_init_wakeup(&client->dev, pdata->wakeup); |
| 264 | |
| 265 | return 0; |
| 266 | |
| 267 | err_free_irq: |
| 268 | free_irq(client->irq, mpr121); |
| 269 | err_free_mem: |
| 270 | input_free_device(input_dev); |
| 271 | kfree(mpr121); |
| 272 | return error; |
| 273 | } |
| 274 | |
| 275 | static int __devexit mpr_touchkey_remove(struct i2c_client *client) |
| 276 | { |
| 277 | struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); |
| 278 | |
| 279 | free_irq(client->irq, mpr121); |
| 280 | input_unregister_device(mpr121->input_dev); |
| 281 | kfree(mpr121); |
| 282 | |
| 283 | return 0; |
| 284 | } |
| 285 | |
| 286 | #ifdef CONFIG_PM_SLEEP |
| 287 | static int mpr_suspend(struct device *dev) |
| 288 | { |
| 289 | struct i2c_client *client = to_i2c_client(dev); |
| 290 | |
| 291 | if (device_may_wakeup(&client->dev)) |
| 292 | enable_irq_wake(client->irq); |
| 293 | |
| 294 | i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00); |
| 295 | |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | static int mpr_resume(struct device *dev) |
| 300 | { |
| 301 | struct i2c_client *client = to_i2c_client(dev); |
| 302 | struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); |
| 303 | |
| 304 | if (device_may_wakeup(&client->dev)) |
| 305 | disable_irq_wake(client->irq); |
| 306 | |
| 307 | i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, |
| 308 | mpr121->keycount); |
| 309 | |
| 310 | return 0; |
| 311 | } |
| 312 | #endif |
| 313 | |
| 314 | static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume); |
| 315 | |
| 316 | static const struct i2c_device_id mpr121_id[] = { |
| 317 | { "mpr121_touchkey", 0 }, |
| 318 | { } |
| 319 | }; |
| 320 | MODULE_DEVICE_TABLE(i2c, mpr121_id); |
| 321 | |
| 322 | static struct i2c_driver mpr_touchkey_driver = { |
| 323 | .driver = { |
| 324 | .name = "mpr121", |
| 325 | .owner = THIS_MODULE, |
| 326 | .pm = &mpr121_touchkey_pm_ops, |
| 327 | }, |
| 328 | .id_table = mpr121_id, |
| 329 | .probe = mpr_touchkey_probe, |
Bill Pemberton | 1cb0aa8 | 2012-11-23 21:27:39 -0800 | [diff] [blame^] | 330 | .remove = mpr_touchkey_remove, |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 331 | }; |
| 332 | |
Axel Lin | 1b92c1c | 2012-03-16 23:05:41 -0700 | [diff] [blame] | 333 | module_i2c_driver(mpr_touchkey_driver); |
Zhang Jiejing | 36682b8 | 2011-05-11 14:32:01 -0700 | [diff] [blame] | 334 | |
| 335 | MODULE_LICENSE("GPL"); |
| 336 | MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); |
| 337 | MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip"); |