1 // SPDX-License-Identifier: GPL-2.0-only
3 * Touchkey driver for Freescale MPR121 Controllor
5 * Copyright (C) 2011 Freescale Semiconductor, Inc.
6 * Author: Zhang Jiejing <jiejing.zhang@freescale.com>
8 * Based on mcs_touchkey.c
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>
18 #include <linux/property.h>
19 #include <linux/regulator/consumer.h>
20 #include <linux/slab.h>
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
39 * ELECTRODE_CONF_ADDR: This register configures the number of
40 * enabled capacitance sensing inputs and its run/suspend mode.
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
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
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];
65 struct mpr121_init_register {
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 },
82 static void mpr121_vdd_supply_disable(void *data)
84 struct regulator *vdd_supply = data;
86 regulator_disable(vdd_supply);
89 static struct regulator *mpr121_vdd_supply_init(struct device *dev)
91 struct regulator *vdd_supply;
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",
101 err = regulator_enable(vdd_supply);
103 dev_err(dev, "failed to enable vdd regulator: %d\n", err);
107 err = devm_add_action(dev, mpr121_vdd_supply_disable, vdd_supply);
109 regulator_disable(vdd_supply);
110 dev_err(dev, "failed to add disable regulator action: %d\n",
118 static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
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;
127 reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
129 dev_err(&client->dev, "i2c read error [%d]\n", reg);
134 reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
136 dev_err(&client->dev, "i2c read error [%d]\n", reg);
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;
147 pressed = reg & BIT(key_num);
148 key_val = mpr121->keycodes[key_num];
150 input_event(input, EV_MSC, MSC_SCAN, key_num);
151 input_report_key(input, key_val, pressed);
153 dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val,
154 pressed ? "pressed" : "released");
163 static int mpr121_phys_init(struct mpr121_touchkey *mpr121,
164 struct i2c_client *client, int vdd_uv)
166 const struct mpr121_init_register *reg;
167 unsigned char usl, lsl, tl, eleconf;
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);
176 ret = i2c_smbus_write_byte_data(client, t + 1,
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);
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).
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);
205 * Quick charge bit will let the capacitive charge to ready
206 * state quickly, or the buttons may not function after system
209 eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE;
210 ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
215 dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount);
220 dev_err(&client->dev, "i2c write error: %d\n", ret);
224 static int mpr_touchkey_probe(struct i2c_client *client,
225 const struct i2c_device_id *id)
227 struct device *dev = &client->dev;
228 struct regulator *vdd_supply;
230 struct mpr121_touchkey *mpr121;
231 struct input_dev *input_dev;
236 dev_err(dev, "irq number should not be zero\n");
240 vdd_supply = mpr121_vdd_supply_init(dev);
241 if (IS_ERR(vdd_supply))
242 return PTR_ERR(vdd_supply);
244 vdd_uv = regulator_get_voltage(vdd_supply);
246 mpr121 = devm_kzalloc(dev, sizeof(*mpr121), GFP_KERNEL);
250 input_dev = devm_input_allocate_device(dev);
254 mpr121->client = client;
255 mpr121->input_dev = input_dev;
256 mpr121->keycount = device_property_count_u32(dev, "linux,keycodes");
257 if (mpr121->keycount > MPR121_MAX_KEY_COUNT) {
258 dev_err(dev, "too many keys defined (%d)\n", mpr121->keycount);
262 error = device_property_read_u32_array(dev, "linux,keycodes",
267 "failed to read linux,keycode property: %d\n", error);
271 input_dev->name = "Freescale MPR121 Touchkey";
272 input_dev->id.bustype = BUS_I2C;
273 input_dev->dev.parent = dev;
274 if (device_property_read_bool(dev, "autorepeat"))
275 __set_bit(EV_REP, input_dev->evbit);
276 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
278 input_dev->keycode = mpr121->keycodes;
279 input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
280 input_dev->keycodemax = mpr121->keycount;
282 for (i = 0; i < mpr121->keycount; i++)
283 input_set_capability(input_dev, EV_KEY, mpr121->keycodes[i]);
285 error = mpr121_phys_init(mpr121, client, vdd_uv);
287 dev_err(dev, "Failed to init register\n");
291 error = devm_request_threaded_irq(dev, client->irq, NULL,
292 mpr_touchkey_interrupt,
293 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
294 dev->driver->name, mpr121);
296 dev_err(dev, "Failed to register interrupt\n");
300 error = input_register_device(input_dev);
304 i2c_set_clientdata(client, mpr121);
305 device_init_wakeup(dev,
306 device_property_read_bool(dev, "wakeup-source"));
311 static int __maybe_unused mpr_suspend(struct device *dev)
313 struct i2c_client *client = to_i2c_client(dev);
315 if (device_may_wakeup(&client->dev))
316 enable_irq_wake(client->irq);
318 i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00);
323 static int __maybe_unused mpr_resume(struct device *dev)
325 struct i2c_client *client = to_i2c_client(dev);
326 struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);
328 if (device_may_wakeup(&client->dev))
329 disable_irq_wake(client->irq);
331 i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
337 static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume);
339 static const struct i2c_device_id mpr121_id[] = {
340 { "mpr121_touchkey", 0 },
343 MODULE_DEVICE_TABLE(i2c, mpr121_id);
346 static const struct of_device_id mpr121_touchkey_dt_match_table[] = {
347 { .compatible = "fsl,mpr121-touchkey" },
350 MODULE_DEVICE_TABLE(of, mpr121_touchkey_dt_match_table);
353 static struct i2c_driver mpr_touchkey_driver = {
356 .pm = &mpr121_touchkey_pm_ops,
357 .of_match_table = of_match_ptr(mpr121_touchkey_dt_match_table),
359 .id_table = mpr121_id,
360 .probe = mpr_touchkey_probe,
363 module_i2c_driver(mpr_touchkey_driver);
365 MODULE_LICENSE("GPL");
366 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
367 MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip");