// SPDX-License-Identifier: GPL-2.0
/*
* Microchip AT42QT1050 QTouch Sensor Controller
*
* Copyright (C) 2019 Pengutronix, Marco Felsch <[email protected]>
*
* Base on AT42QT1070 driver by:
* Bo Shen <[email protected]>
* Copyright (C) 2011 Atmel
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
/* Chip ID */
#define QT1050_CHIP_ID 0x00
#define QT1050_CHIP_ID_VER 0x46
/* Firmware version */
#define QT1050_FW_VERSION 0x01
/* Detection status */
#define QT1050_DET_STATUS 0x02
/* Key status */
#define QT1050_KEY_STATUS 0x03
/* Key Signals */
#define QT1050_KEY_SIGNAL_0_MSB 0x06
#define QT1050_KEY_SIGNAL_0_LSB 0x07
#define QT1050_KEY_SIGNAL_1_MSB 0x08
#define QT1050_KEY_SIGNAL_1_LSB 0x09
#define QT1050_KEY_SIGNAL_2_MSB 0x0c
#define QT1050_KEY_SIGNAL_2_LSB 0x0d
#define QT1050_KEY_SIGNAL_3_MSB 0x0e
#define QT1050_KEY_SIGNAL_3_LSB 0x0f
#define QT1050_KEY_SIGNAL_4_MSB 0x10
#define QT1050_KEY_SIGNAL_4_LSB 0x11
/* Reference data */
#define QT1050_REF_DATA_0_MSB 0x14
#define QT1050_REF_DATA_0_LSB 0x15
#define QT1050_REF_DATA_1_MSB 0x16
#define QT1050_REF_DATA_1_LSB 0x17
#define QT1050_REF_DATA_2_MSB 0x1a
#define QT1050_REF_DATA_2_LSB 0x1b
#define QT1050_REF_DATA_3_MSB 0x1c
#define QT1050_REF_DATA_3_LSB 0x1d
#define QT1050_REF_DATA_4_MSB 0x1e
#define QT1050_REF_DATA_4_LSB 0x1f
/* Negative threshold level */
#define QT1050_NTHR_0 0x21
#define QT1050_NTHR_1 0x22
#define QT1050_NTHR_2 0x24
#define QT1050_NTHR_3 0x25
#define QT1050_NTHR_4 0x26
/* Pulse / Scale */
#define QT1050_PULSE_SCALE_0 0x28
#define QT1050_PULSE_SCALE_1 0x29
#define QT1050_PULSE_SCALE_2 0x2b
#define QT1050_PULSE_SCALE_3 0x2c
#define QT1050_PULSE_SCALE_4 0x2d
/* Detection integrator counter / AKS */
#define QT1050_DI_AKS_0 0x2f
#define QT1050_DI_AKS_1 0x30
#define QT1050_DI_AKS_2 0x32
#define QT1050_DI_AKS_3 0x33
#define QT1050_DI_AKS_4 0x34
/* Charge Share Delay */
#define QT1050_CSD_0 0x36
#define QT1050_CSD_1 0x37
#define QT1050_CSD_2 0x39
#define QT1050_CSD_3 0x3a
#define QT1050_CSD_4 0x3b
/* Low Power Mode */
#define QT1050_LPMODE 0x3d
/* Calibration and Reset */
#define QT1050_RES_CAL 0x3f
#define QT1050_RES_CAL_RESET BIT(7)
#define QT1050_RES_CAL_CALIBRATE BIT(1)
#define QT1050_MAX_KEYS 5
#define QT1050_RESET_TIME 255
struct qt1050_key_regs {
unsigned int nthr;
unsigned int pulse_scale;
unsigned int di_aks;
unsigned int csd;
};
struct qt1050_key {
u32 num;
u32 charge_delay;
u32 thr_cnt;
u32 samples;
u32 scale;
u32 keycode;
};
struct qt1050_priv {
struct i2c_client *client;
struct input_dev *input;
struct regmap *regmap;
struct qt1050_key keys[QT1050_MAX_KEYS];
unsigned short keycodes[QT1050_MAX_KEYS];
u8 reg_keys;
u8 last_keys;
};
static const struct qt1050_key_regs qt1050_key_regs_data[] = {
{
.nthr = QT1050_NTHR_0,
.pulse_scale = QT1050_PULSE_SCALE_0,
.di_aks = QT1050_DI_AKS_0,
.csd = QT1050_CSD_0,
}, {
.nthr = QT1050_NTHR_1,
.pulse_scale = QT1050_PULSE_SCALE_1,
.di_aks = QT1050_DI_AKS_1,
.csd = QT1050_CSD_1,
}, {
.nthr = QT1050_NTHR_2,
.pulse_scale = QT1050_PULSE_SCALE_2,
.di_aks = QT1050_DI_AKS_2,
.csd = QT1050_CSD_2,
}, {
.nthr = QT1050_NTHR_3,
.pulse_scale = QT1050_PULSE_SCALE_3,
.di_aks = QT1050_DI_AKS_3,
.csd = QT1050_CSD_3,
}, {
.nthr = QT1050_NTHR_4,
.pulse_scale = QT1050_PULSE_SCALE_4,
.di_aks = QT1050_DI_AKS_4,
.csd = QT1050_CSD_4,
}
};
static bool qt1050_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case QT1050_DET_STATUS:
case QT1050_KEY_STATUS:
case QT1050_KEY_SIGNAL_0_MSB:
case QT1050_KEY_SIGNAL_0_LSB:
case QT1050_KEY_SIGNAL_1_MSB:
case QT1050_KEY_SIGNAL_1_LSB:
case QT1050_KEY_SIGNAL_2_MSB:
case QT1050_KEY_SIGNAL_2_LSB:
case QT1050_KEY_SIGNAL_3_MSB:
case QT1050_KEY_SIGNAL_3_LSB:
case QT1050_KEY_SIGNAL_4_MSB:
case QT1050_KEY_SIGNAL_4_LSB:
return true;
default:
return false;
}
}
static const struct regmap_range qt1050_readable_ranges[] = {
regmap_reg_range(QT1050_CHIP_ID, QT1050_KEY_STATUS),
regmap_reg_range(QT1050_KEY_SIGNAL_0_MSB, QT1050_KEY_SIGNAL_1_LSB),
regmap_reg_range(QT1050_KEY_SIGNAL_2_MSB, QT1050_KEY_SIGNAL_4_LSB),
regmap_reg_range(QT1050_REF_DATA_0_MSB, QT1050_REF_DATA_1_LSB),
regmap_reg_range(QT1050_REF_DATA_2_MSB, QT1050_REF_DATA_4_LSB),
regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
};
static const struct regmap_access_table qt1050_readable_table = {
.yes_ranges = qt1050_readable_ranges,
.n_yes_ranges = ARRAY_SIZE(qt1050_readable_ranges),
};
static const struct regmap_range qt1050_writeable_ranges[] = {
regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
};
static const struct regmap_access_table qt1050_writeable_table = {
.yes_ranges = qt1050_writeable_ranges,
.n_yes_ranges = ARRAY_SIZE(qt1050_writeable_ranges),
};
static const struct regmap_config qt1050_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = QT1050_RES_CAL,
.cache_type = REGCACHE_MAPLE,
.wr_table = &qt1050_writeable_table,
.rd_table = &qt1050_readable_table,
.volatile_reg = qt1050_volatile_reg,
};
static bool qt1050_identify(struct qt1050_priv *ts)
{
unsigned int val;
int err;
/* Read Chip ID */
err = regmap_read(ts->regmap, QT1050_CHIP_ID, &val);
if (err) {
dev_err(&ts->client->dev, "Failed to read chip ID: %d\n", err);
return false;
}
if (val != QT1050_CHIP_ID_VER) {
dev_err(&ts->client->dev, "ID %d not supported\n", val);
return false;
}
/* Read firmware version */
err = regmap_read(ts->regmap, QT1050_FW_VERSION, &val);
if (err) {
dev_err(&ts->client->dev, "could not read the firmware version\n");
return false;
}
dev_info(&ts->client->dev, "AT42QT1050 firmware version %1d.%1d\n",
val >> 4, val & 0xf);
return true;
}
static irqreturn_t qt1050_irq_threaded(int irq, void *dev_id)
{
struct qt1050_priv *ts = dev_id;
struct input_dev *input = ts->input;
unsigned long new_keys, changed;
unsigned int val;
int i, err;
/* Read the detected status register, thus clearing interrupt */
err = regmap_read(ts->regmap, QT1050_DET_STATUS, &val);
if (err) {
dev_err(&ts->client->dev, "Fail to read detection status: %d\n",
err);
return IRQ_NONE;
}
/* Read which key changed, keys are not continuous */
err = regmap_read(ts->regmap, QT1050_KEY_STATUS, &val);
if (err) {
dev_err(&ts->client->dev,
"Fail to determine the key status: %d\n", err);
return IRQ_NONE;
}
new_keys = (val & 0x70) >> 2 | (val & 0x6) >> 1;
changed = ts->last_keys ^ new_keys;
/* Report registered keys only */
changed &= ts->reg_keys;
for_each_set_bit(i, &changed, QT1050_MAX_KEYS)
input_report_key(input, ts->keys[i].keycode,
test_bit(i, &new_keys));
ts->last_keys = new_keys;
input_sync(input);
return IRQ_HANDLED;
}
static const struct qt1050_key_regs *qt1050_get_key_regs(int key_num)
{
return &qt1050_key_regs_data[key_num];
}
static int qt1050_set_key(struct regmap *map, int number, int on)
{
const struct qt1050_key_regs *key_regs;
key_regs = qt1050_get_key_regs(number);
return regmap_update_bits(map, key_regs->di_aks, 0xfc,
on ? BIT(4) : 0x00);
}
static int qt1050_apply_fw_data(struct qt1050_priv *ts)
{
struct regmap *map = ts->regmap;
struct qt1050_key *button = &ts->keys[0];
const struct qt1050_key_regs *key_regs;
int i, err;
/* Disable all keys and enable only the specified ones */
for (i = 0; i < QT1050_MAX_KEYS; i++) {
err = qt1050_set_key(map, i, 0);
if (err)
return err;
}
for (i = 0; i < QT1050_MAX_KEYS; i++, button++) {
/* Keep KEY_RESERVED keys off */
if (button->keycode == KEY_RESERVED)
continue;
err = qt1050_set_key(map, button->num, 1);
if (err)
return err;
key_regs = qt1050_get_key_regs(button->num);
err = regmap_write(map, key_regs->pulse_scale,
(button->samples << 4) | (button->scale));
if (err)
return err;
err = regmap_write(map, key_regs->csd, button->charge_delay);
if (err)
return err;
err = regmap_write(map, key_regs->nthr, button->thr_cnt);
if (err)
return err;
}
return 0;
}
static int qt1050_parse_fw(struct qt1050_priv *ts)
{
struct device *dev = &ts->client->dev;
int nbuttons;
nbuttons = device_get_child_node_count(dev);
if (nbuttons == 0 || nbuttons > QT1050_MAX_KEYS)
return -ENODEV;
device_for_each_child_node_scoped(dev, child) {
struct qt1050_key button;
/* Required properties */
if (fwnode_property_read_u32(child, "linux,code",
&button.keycode)) {
dev_err(dev, "Button without keycode\n");
return -EINVAL;
}
if (button.keycode >= KEY_MAX) {
dev_err(dev, "Invalid keycode 0x%x\n",
button.keycode);
return -EINVAL;
}
if (fwnode_property_read_u32(child, "reg",
&button.num)) {
dev_err(dev, "Button without pad number\n");
return -EINVAL;
}
if (button.num < 0 || button.num > QT1050_MAX_KEYS - 1)
return -EINVAL;
ts->reg_keys |= BIT(button.num);
/* Optional properties */
if (fwnode_property_read_u32(child,
"microchip,pre-charge-time-ns",
&button.charge_delay)) {
button.charge_delay = 0;
} else {
if (button.charge_delay % 2500 == 0)
button.charge_delay =
button.charge_delay / 2500;
else
button.charge_delay = 0;
}
if (fwnode_property_read_u32(child, "microchip,average-samples",
&button.samples)) {
button.samples = 0;
} else {
if (is_power_of_2(button.samples))
button.samples = ilog2(button.samples);
else
button.samples = 0;
}
if (fwnode_property_read_u32(child, "microchip,average-scaling",
&button.scale)) {
button.scale = 0;
} else {
if (is_power_of_2(button.scale))
button.scale = ilog2(button.scale);
else
button.scale = 0;
}
if (fwnode_property_read_u32(child, "microchip,threshold",
&button.thr_cnt)) {
button.thr_cnt = 20;
} else {
if (button.thr_cnt > 255)
button.thr_cnt = 20;
}
ts->keys[button.num] = button;
}
return 0;
}
static int qt1050_probe(struct i2c_client *client)
{
struct qt1050_priv *ts;
struct input_dev *input;
struct device *dev = &client->dev;
struct regmap *map;
unsigned int status, i;
int err;
/* Check basic functionality */
err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
if (!err) {
dev_err(&client->dev, "%s adapter not supported\n",
dev_driver_string(&client->adapter->dev));
return -ENODEV;
}
if (!client->irq) {
dev_err(dev, "assign a irq line to this device\n");
return -EINVAL;
}
ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
if (!ts)
return -ENOMEM;
input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
map = devm_regmap_init_i2c(client, &qt1050_regmap_config);
if (IS_ERR(map))
return PTR_ERR(map);
ts->client = client;
ts->input = input;
ts->regmap = map;
i2c_set_clientdata(client, ts);
/* Identify the qt1050 chip */
if (!qt1050_identify(ts))
return -ENODEV;
/* Get pdata */
err = qt1050_parse_fw(ts);
if (err) {
dev_err(dev, "Failed to parse firmware: %d\n", err);
return err;
}
input->name = "AT42QT1050 QTouch Sensor";
input->dev.parent = &client->dev;
input->id.bustype = BUS_I2C;
/* Add the keycode */
input->keycode = ts->keycodes;
input->keycodesize = sizeof(ts->keycodes[0]);
input->keycodemax = QT1050_MAX_KEYS;
__set_bit(EV_KEY, input->evbit);
for (i = 0; i < QT1050_MAX_KEYS; i++) {
ts->keycodes[i] = ts->keys[i].keycode;
__set_bit(ts->keycodes[i], input->keybit);
}
/* Trigger re-calibration */
err = regmap_update_bits(ts->regmap, QT1050_RES_CAL, 0x7f,
QT1050_RES_CAL_CALIBRATE);
if (err) {
dev_err(dev, "Trigger calibration failed: %d\n", err);
return err;
}
err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
status >> 7 == 1, 10000, 200000);
if (err) {
dev_err(dev, "Calibration failed: %d\n", err);
return err;
}
/* Soft reset to set defaults */
err = regmap_update_bits(ts->regmap, QT1050_RES_CAL,
QT1050_RES_CAL_RESET, QT1050_RES_CAL_RESET);
if (err) {
dev_err(dev, "Trigger soft reset failed: %d\n", err);
return err;
}
msleep(QT1050_RESET_TIME);
/* Set pdata */
err = qt1050_apply_fw_data(ts);
if (err) {
dev_err(dev, "Failed to set firmware data: %d\n", err);
return err;
}
err = devm_request_threaded_irq(dev, client->irq, NULL,
qt1050_irq_threaded, IRQF_ONESHOT,
"qt1050", ts);
if (err) {
dev_err(&client->dev, "Failed to request irq: %d\n", err);
return err;
}
/* Clear #CHANGE line */
err = regmap_read(ts->regmap, QT1050_DET_STATUS, &status);
if (err) {
dev_err(dev, "Failed to clear #CHANGE line level: %d\n", err);
return err;
}
/* Register the input device */
err = input_register_device(ts->input);
if (err) {
dev_err(&client->dev, "Failed to register input device: %d\n",
err);
return err;
}
return 0;
}
static int qt1050_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct qt1050_priv *ts = i2c_get_clientdata(client);
disable_irq(client->irq);
/*
* Set measurement interval to 1s (125 x 8ms) if wakeup is allowed
* else turn off. The 1s interval seems to be a good compromise between
* low power and response time.
*/
return regmap_write(ts->regmap, QT1050_LPMODE,
device_may_wakeup(dev) ? 125 : 0);
}
static int qt1050_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct qt1050_priv *ts = i2c_get_clientdata(client);
enable_irq(client->irq);
/* Set measurement interval back to 16ms (2 x 8ms) */
return regmap_write(ts->regmap, QT1050_LPMODE, 2);
}
static DEFINE_SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
static const struct of_device_id __maybe_unused qt1050_of_match[] = {
{ .compatible = "microchip,qt1050", },
{ },
};
MODULE_DEVICE_TABLE(of, qt1050_of_match);
static struct i2c_driver qt1050_driver = {
.driver = {
.name = "qt1050",
.of_match_table = of_match_ptr(qt1050_of_match),
.pm = pm_sleep_ptr(&qt1050_pm_ops),
},
.probe = qt1050_probe,
};
module_i2c_driver(qt1050_driver);
MODULE_AUTHOR("Marco Felsch <[email protected]");
MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
MODULE_LICENSE("GPL v2");
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