// SPDX-License-Identifier: GPL-2.0-only
/*
* Input driver for Microchip CAP11xx based capacitive touch sensors
*
* (c) 2014 Daniel Mack <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/leds.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/i2c.h>
#include <linux/gpio/consumer.h>
#include <linux/bitfield.h>
#define CAP11XX_REG_MAIN_CONTROL 0x00
#define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6)
#define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0)
#define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4)
#define CAP11XX_REG_GENERAL_STATUS 0x02
#define CAP11XX_REG_SENSOR_INPUT 0x03
#define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a
#define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X))
#define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f
#define CAP11XX_REG_SENSITIVITY_CONTROL_DELTA_SENSE_MASK 0x70
#define CAP11XX_REG_CONFIG 0x20
#define CAP11XX_REG_SENSOR_ENABLE 0x21
#define CAP11XX_REG_SENSOR_CONFIG 0x22
#define CAP11XX_REG_SENSOR_CONFIG2 0x23
#define CAP11XX_REG_SAMPLING_CONFIG 0x24
#define CAP11XX_REG_CALIBRATION 0x26
#define CAP11XX_REG_INT_ENABLE 0x27
#define CAP11XX_REG_REPEAT_RATE 0x28
#define CAP11XX_REG_SIGNAL_GUARD_ENABLE 0x29
#define CAP11XX_REG_MT_CONFIG 0x2a
#define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b
#define CAP11XX_REG_MT_PATTERN 0x2d
#define CAP11XX_REG_RECALIB_CONFIG 0x2f
#define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X))
#define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38
#define CAP11XX_REG_STANDBY_CHANNEL 0x40
#define CAP11XX_REG_STANDBY_CONFIG 0x41
#define CAP11XX_REG_STANDBY_SENSITIVITY 0x42
#define CAP11XX_REG_STANDBY_THRESH 0x43
#define CAP11XX_REG_CONFIG2 0x44
#define CAP11XX_REG_CONFIG2_ALT_POL BIT(6)
#define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X))
#define CAP11XX_REG_LED_POLARITY 0x73
#define CAP11XX_REG_LED_OUTPUT_CONTROL 0x74
#define CAP11XX_REG_CALIB_SENSITIVITY_CONFIG 0x80
#define CAP11XX_REG_CALIB_SENSITIVITY_CONFIG2 0x81
#define CAP11XX_REG_LED_DUTY_CYCLE_1 0x90
#define CAP11XX_REG_LED_DUTY_CYCLE_2 0x91
#define CAP11XX_REG_LED_DUTY_CYCLE_3 0x92
#define CAP11XX_REG_LED_DUTY_CYCLE_4 0x93
#define CAP11XX_REG_LED_DUTY_MIN_MASK (0x0f)
#define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT (0)
#define CAP11XX_REG_LED_DUTY_MAX_MASK (0xf0)
#define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT (4)
#define CAP11XX_REG_LED_DUTY_MAX_VALUE (15)
#define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X))
#define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9
#define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba
#define CAP11XX_REG_PRODUCT_ID 0xfd
#define CAP11XX_REG_MANUFACTURER_ID 0xfe
#define CAP11XX_REG_REVISION 0xff
#define CAP11XX_MANUFACTURER_ID 0x5d
#ifdef CONFIG_LEDS_CLASS
struct cap11xx_led {
struct cap11xx_priv *priv;
struct led_classdev cdev;
u32 reg;
};
#endif
struct cap11xx_priv {
struct regmap *regmap;
struct device *dev;
struct input_dev *idev;
const struct cap11xx_hw_model *model;
struct cap11xx_led *leds;
int num_leds;
/* config */
u8 analog_gain;
u8 sensitivity_delta_sense;
u8 signal_guard_inputs_mask;
u32 thresholds[8];
u32 calib_sensitivities[8];
u32 keycodes[];
};
struct cap11xx_hw_model {
u8 product_id;
unsigned int num_channels;
unsigned int num_leds;
bool has_gain;
bool has_irq_config;
bool has_sensitivity_control;
bool has_signal_guard;
};
static const struct reg_default cap11xx_reg_defaults[] = {
{ CAP11XX_REG_MAIN_CONTROL, 0x00 },
{ CAP11XX_REG_GENERAL_STATUS, 0x00 },
{ CAP11XX_REG_SENSOR_INPUT, 0x00 },
{ CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 },
{ CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f },
{ CAP11XX_REG_CONFIG, 0x20 },
{ CAP11XX_REG_SENSOR_ENABLE, 0x3f },
{ CAP11XX_REG_SENSOR_CONFIG, 0xa4 },
{ CAP11XX_REG_SENSOR_CONFIG2, 0x07 },
{ CAP11XX_REG_SAMPLING_CONFIG, 0x39 },
{ CAP11XX_REG_CALIBRATION, 0x00 },
{ CAP11XX_REG_INT_ENABLE, 0x3f },
{ CAP11XX_REG_REPEAT_RATE, 0x3f },
{ CAP11XX_REG_MT_CONFIG, 0x80 },
{ CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 },
{ CAP11XX_REG_MT_PATTERN, 0x3f },
{ CAP11XX_REG_RECALIB_CONFIG, 0x8a },
{ CAP11XX_REG_SENSOR_THRESH(0), 0x40 },
{ CAP11XX_REG_SENSOR_THRESH(1), 0x40 },
{ CAP11XX_REG_SENSOR_THRESH(2), 0x40 },
{ CAP11XX_REG_SENSOR_THRESH(3), 0x40 },
{ CAP11XX_REG_SENSOR_THRESH(4), 0x40 },
{ CAP11XX_REG_SENSOR_THRESH(5), 0x40 },
{ CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 },
{ CAP11XX_REG_STANDBY_CHANNEL, 0x00 },
{ CAP11XX_REG_STANDBY_CONFIG, 0x39 },
{ CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 },
{ CAP11XX_REG_STANDBY_THRESH, 0x40 },
{ CAP11XX_REG_CONFIG2, 0x40 },
{ CAP11XX_REG_LED_POLARITY, 0x00 },
{ CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 },
{ CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 },
};
static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case CAP11XX_REG_MAIN_CONTROL:
case CAP11XX_REG_SENSOR_INPUT:
case CAP11XX_REG_SENOR_DELTA(0):
case CAP11XX_REG_SENOR_DELTA(1):
case CAP11XX_REG_SENOR_DELTA(2):
case CAP11XX_REG_SENOR_DELTA(3):
case CAP11XX_REG_SENOR_DELTA(4):
case CAP11XX_REG_SENOR_DELTA(5):
return true;
}
return false;
}
static const struct regmap_config cap11xx_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = CAP11XX_REG_REVISION,
.reg_defaults = cap11xx_reg_defaults,
.num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
.cache_type = REGCACHE_MAPLE,
.volatile_reg = cap11xx_volatile_reg,
};
static int cap11xx_write_calib_sens_config_1(struct cap11xx_priv *priv)
{
return regmap_write(priv->regmap,
CAP11XX_REG_CALIB_SENSITIVITY_CONFIG,
(priv->calib_sensitivities[3] << 6) |
(priv->calib_sensitivities[2] << 4) |
(priv->calib_sensitivities[1] << 2) |
priv->calib_sensitivities[0]);
}
static int cap11xx_write_calib_sens_config_2(struct cap11xx_priv *priv)
{
return regmap_write(priv->regmap,
CAP11XX_REG_CALIB_SENSITIVITY_CONFIG2,
(priv->calib_sensitivities[7] << 6) |
(priv->calib_sensitivities[6] << 4) |
(priv->calib_sensitivities[5] << 2) |
priv->calib_sensitivities[4]);
}
static int cap11xx_init_keys(struct cap11xx_priv *priv)
{
struct device_node *node = priv->dev->of_node;
struct device *dev = priv->dev;
int i, error;
u32 u32_val;
if (!node) {
dev_err(dev, "Corresponding DT entry is not available\n");
return -ENODEV;
}
if (!of_property_read_u32(node, "microchip,sensor-gain", &u32_val)) {
if (!priv->model->has_gain) {
dev_warn(dev,
"This model doesn't support 'sensor-gain'\n");
} else if (is_power_of_2(u32_val) && u32_val <= 8) {
priv->analog_gain = (u8)ilog2(u32_val);
error = regmap_update_bits(priv->regmap,
CAP11XX_REG_MAIN_CONTROL,
CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
priv->analog_gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
if (error)
return error;
} else {
dev_err(dev, "Invalid sensor-gain value %u\n", u32_val);
return -EINVAL;
}
}
if (of_property_read_bool(node, "microchip,irq-active-high")) {
if (priv->model->has_irq_config) {
error = regmap_update_bits(priv->regmap,
CAP11XX_REG_CONFIG2,
CAP11XX_REG_CONFIG2_ALT_POL,
0);
if (error)
return error;
} else {
dev_warn(dev,
"This model doesn't support 'irq-active-high'\n");
}
}
if (!of_property_read_u32(node, "microchip,sensitivity-delta-sense", &u32_val)) {
if (!is_power_of_2(u32_val) || u32_val > 128) {
dev_err(dev, "Invalid sensitivity-delta-sense value %u\n", u32_val);
return -EINVAL;
}
priv->sensitivity_delta_sense = (u8)ilog2(u32_val);
u32_val = ~(FIELD_PREP(CAP11XX_REG_SENSITIVITY_CONTROL_DELTA_SENSE_MASK,
priv->sensitivity_delta_sense));
error = regmap_update_bits(priv->regmap,
CAP11XX_REG_SENSITIVITY_CONTROL,
CAP11XX_REG_SENSITIVITY_CONTROL_DELTA_SENSE_MASK,
u32_val);
if (error)
return error;
}
if (!of_property_read_u32_array(node, "microchip,input-threshold",
priv->thresholds, priv->model->num_channels)) {
for (i = 0; i < priv->model->num_channels; i++) {
if (priv->thresholds[i] > 127) {
dev_err(dev, "Invalid input-threshold value %u\n",
priv->thresholds[i]);
return -EINVAL;
}
error = regmap_write(priv->regmap,
CAP11XX_REG_SENSOR_THRESH(i),
priv->thresholds[i]);
if (error)
return error;
}
}
if (!of_property_read_u32_array(node, "microchip,calib-sensitivity",
priv->calib_sensitivities,
priv->model->num_channels)) {
if (priv->model->has_sensitivity_control) {
for (i = 0; i < priv->model->num_channels; i++) {
if (!is_power_of_2(priv->calib_sensitivities[i]) ||
priv->calib_sensitivities[i] > 4) {
dev_err(dev, "Invalid calib-sensitivity value %u\n",
priv->calib_sensitivities[i]);
return -EINVAL;
}
priv->calib_sensitivities[i] = ilog2(priv->calib_sensitivities[i]);
}
error = cap11xx_write_calib_sens_config_1(priv);
if (error)
return error;
if (priv->model->num_channels > 4) {
error = cap11xx_write_calib_sens_config_2(priv);
if (error)
return error;
}
} else {
dev_warn(dev,
"This model doesn't support 'calib-sensitivity'\n");
}
}
for (i = 0; i < priv->model->num_channels; i++) {
if (!of_property_read_u32_index(node, "microchip,signal-guard",
i, &u32_val)) {
if (u32_val > 1)
return -EINVAL;
if (u32_val)
priv->signal_guard_inputs_mask |= 0x01 << i;
}
}
if (priv->signal_guard_inputs_mask) {
if (priv->model->has_signal_guard) {
error = regmap_write(priv->regmap,
CAP11XX_REG_SIGNAL_GUARD_ENABLE,
priv->signal_guard_inputs_mask);
if (error)
return error;
} else {
dev_warn(dev,
"This model doesn't support 'signal-guard'\n");
}
}
/* Provide some useful defaults */
for (i = 0; i < priv->model->num_channels; i++)
priv->keycodes[i] = KEY_A + i;
of_property_read_u32_array(node, "linux,keycodes",
priv->keycodes, priv->model->num_channels);
/* Disable autorepeat. The Linux input system has its own handling. */
error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
if (error)
return error;
return 0;
}
static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
{
struct cap11xx_priv *priv = data;
unsigned int status;
int ret, i;
/*
* Deassert interrupt. This needs to be done before reading the status
* registers, which will not carry valid values otherwise.
*/
ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
if (ret < 0)
goto out;
ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
if (ret < 0)
goto out;
for (i = 0; i < priv->idev->keycodemax; i++)
input_report_key(priv->idev, priv->keycodes[i],
status & (1 << i));
input_sync(priv->idev);
out:
return IRQ_HANDLED;
}
static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
{
/*
* DLSEEP mode will turn off all LEDS, prevent this
*/
if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds)
return 0;
return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
CAP11XX_REG_MAIN_CONTROL_DLSEEP,
sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
}
static int cap11xx_input_open(struct input_dev *idev)
{
struct cap11xx_priv *priv = input_get_drvdata(idev);
return cap11xx_set_sleep(priv, false);
}
static void cap11xx_input_close(struct input_dev *idev)
{
struct cap11xx_priv *priv = input_get_drvdata(idev);
cap11xx_set_sleep(priv, true);
}
#ifdef CONFIG_LEDS_CLASS
static int cap11xx_led_set(struct led_classdev *cdev,
enum led_brightness value)
{
struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
struct cap11xx_priv *priv = led->priv;
/*
* All LEDs share the same duty cycle as this is a HW
* limitation. Brightness levels per LED are either
* 0 (OFF) and 1 (ON).
*/
return regmap_update_bits(priv->regmap,
CAP11XX_REG_LED_OUTPUT_CONTROL,
BIT(led->reg),
value ? BIT(led->reg) : 0);
}
static int cap11xx_init_leds(struct device *dev,
struct cap11xx_priv *priv, int num_leds)
{
struct device_node *node = dev->of_node, *child;
struct cap11xx_led *led;
int cnt = of_get_child_count(node);
int error;
if (!num_leds || !cnt)
return 0;
if (cnt > num_leds)
return -EINVAL;
led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL);
if (!led)
return -ENOMEM;
priv->leds = led;
error = regmap_update_bits(priv->regmap,
CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
if (error)
return error;
error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4,
CAP11XX_REG_LED_DUTY_MAX_MASK,
CAP11XX_REG_LED_DUTY_MAX_VALUE <<
CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT);
if (error)
return error;
for_each_child_of_node(node, child) {
u32 reg;
led->cdev.name =
of_get_property(child, "label", NULL) ? : child->name;
led->cdev.default_trigger =
of_get_property(child, "linux,default-trigger", NULL);
led->cdev.flags = 0;
led->cdev.brightness_set_blocking = cap11xx_led_set;
led->cdev.max_brightness = 1;
led->cdev.brightness = LED_OFF;
error = of_property_read_u32(child, "reg", ®);
if (error != 0 || reg >= num_leds) {
of_node_put(child);
return -EINVAL;
}
led->reg = reg;
led->priv = priv;
error = devm_led_classdev_register(dev, &led->cdev);
if (error) {
of_node_put(child);
return error;
}
priv->num_leds++;
led++;
}
return 0;
}
#else
static int cap11xx_init_leds(struct device *dev,
struct cap11xx_priv *priv, int num_leds)
{
return 0;
}
#endif
static int cap11xx_i2c_probe(struct i2c_client *i2c_client)
{
const struct i2c_device_id *id;
const struct cap11xx_hw_model *cap;
struct device *dev = &i2c_client->dev;
struct cap11xx_priv *priv;
int i, error;
unsigned int val, rev;
id = i2c_client_get_device_id(i2c_client);
cap = i2c_get_match_data(i2c_client);
if (!id || !cap || !cap->num_channels) {
dev_err(dev, "Invalid device configuration\n");
return -EINVAL;
}
priv = devm_kzalloc(dev,
struct_size(priv, keycodes, cap->num_channels),
GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
if (error)
return error;
if (val != cap->product_id) {
dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
val, cap->product_id);
return -ENXIO;
}
error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
if (error)
return error;
if (val != CAP11XX_MANUFACTURER_ID) {
dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
val, CAP11XX_MANUFACTURER_ID);
return -ENXIO;
}
error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
if (error < 0)
return error;
dev_info(dev, "CAP11XX detected, model %s, revision 0x%02x\n",
id->name, rev);
priv->model = cap;
dev_info(dev, "CAP11XX device detected, model %s, revision 0x%02x\n",
id->name, rev);
error = cap11xx_init_keys(priv);
if (error)
return error;
priv->idev = devm_input_allocate_device(dev);
if (!priv->idev)
return -ENOMEM;
priv->idev->name = "CAP11XX capacitive touch sensor";
priv->idev->id.bustype = BUS_I2C;
priv->idev->evbit[0] = BIT_MASK(EV_KEY);
if (of_property_read_bool(dev->of_node, "autorepeat"))
__set_bit(EV_REP, priv->idev->evbit);
for (i = 0; i < cap->num_channels; i++)
__set_bit(priv->keycodes[i], priv->idev->keybit);
__clear_bit(KEY_RESERVED, priv->idev->keybit);
priv->idev->keycode = priv->keycodes;
priv->idev->keycodesize = sizeof(priv->keycodes[0]);
priv->idev->keycodemax = cap->num_channels;
priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
priv->idev->id.product = cap->product_id;
priv->idev->id.version = rev;
priv->idev->open = cap11xx_input_open;
priv->idev->close = cap11xx_input_close;
error = cap11xx_init_leds(dev, priv, cap->num_leds);
if (error)
return error;
input_set_drvdata(priv->idev, priv);
/*
* Put the device in deep sleep mode for now.
* ->open() will bring it back once the it is actually needed.
*/
cap11xx_set_sleep(priv, true);
error = input_register_device(priv->idev);
if (error)
return error;
error = devm_request_threaded_irq(dev, i2c_client->irq,
NULL, cap11xx_thread_func,
IRQF_ONESHOT, dev_name(dev), priv);
if (error)
return error;
return 0;
}
static const struct cap11xx_hw_model cap1106_model = {
.product_id = 0x55, .num_channels = 6, .num_leds = 0,
.has_gain = true,
.has_irq_config = true,
};
static const struct cap11xx_hw_model cap1126_model = {
.product_id = 0x53, .num_channels = 6, .num_leds = 2,
.has_gain = true,
.has_irq_config = true,
};
static const struct cap11xx_hw_model cap1188_model = {
.product_id = 0x50, .num_channels = 8, .num_leds = 8,
.has_gain = true,
.has_irq_config = true,
};
static const struct cap11xx_hw_model cap1203_model = {
.product_id = 0x6d, .num_channels = 3, .num_leds = 0,
};
static const struct cap11xx_hw_model cap1206_model = {
.product_id = 0x67, .num_channels = 6, .num_leds = 0,
};
static const struct cap11xx_hw_model cap1293_model = {
.product_id = 0x6f, .num_channels = 3, .num_leds = 0,
.has_gain = true,
.has_sensitivity_control = true,
.has_signal_guard = true,
};
static const struct cap11xx_hw_model cap1298_model = {
.product_id = 0x71, .num_channels = 8, .num_leds = 0,
.has_gain = true,
.has_sensitivity_control = true,
.has_signal_guard = true,
};
static const struct of_device_id cap11xx_dt_ids[] = {
{ .compatible = "microchip,cap1106", .data = &cap1106_model },
{ .compatible = "microchip,cap1126", .data = &cap1126_model },
{ .compatible = "microchip,cap1188", .data = &cap1188_model },
{ .compatible = "microchip,cap1203", .data = &cap1203_model },
{ .compatible = "microchip,cap1206", .data = &cap1206_model },
{ .compatible = "microchip,cap1293", .data = &cap1293_model },
{ .compatible = "microchip,cap1298", .data = &cap1298_model },
{ }
};
MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
static const struct i2c_device_id cap11xx_i2c_ids[] = {
{ "cap1106", (kernel_ulong_t)&cap1106_model },
{ "cap1126", (kernel_ulong_t)&cap1126_model },
{ "cap1188", (kernel_ulong_t)&cap1188_model },
{ "cap1203", (kernel_ulong_t)&cap1203_model },
{ "cap1206", (kernel_ulong_t)&cap1206_model },
{ "cap1293", (kernel_ulong_t)&cap1293_model },
{ "cap1298", (kernel_ulong_t)&cap1298_model },
{ }
};
MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
static struct i2c_driver cap11xx_i2c_driver = {
.driver = {
.name = "cap11xx",
.of_match_table = cap11xx_dt_ids,
},
.id_table = cap11xx_i2c_ids,
.probe = cap11xx_i2c_probe,
};
module_i2c_driver(cap11xx_i2c_driver);
MODULE_DESCRIPTION("Microchip CAP11XX driver");
MODULE_AUTHOR("Daniel Mack <[email protected]>");
MODULE_LICENSE("GPL v2");
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