/*
* Input driver for Microchip CAP11xx based capacitive touch sensors
*
* (c) 2014 Daniel Mack <linux@zonque.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/of_irq.h>
#include <linux/regmap.h>
#include <linux/i2c.h>
#include <linux/gpio/consumer.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_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_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_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
struct cap11xx_priv {
struct regmap *regmap;
struct input_dev *idev;
/* config */
u32 keycodes[];
};
struct cap11xx_hw_model {
u8 product_id;
unsigned int num_channels;
};
enum {
CAP1106,
CAP1126,
CAP1188,
};
static const struct cap11xx_hw_model cap11xx_devices[] = {
[CAP1106] = { .product_id = 0x55, .num_channels = 6 },
[CAP1126] = { .product_id = 0x53, .num_channels = 6 },
[CAP1188] = { .product_id = 0x50, .num_channels = 8 },
};
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_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):
case CAP11XX_REG_PRODUCT_ID:
case CAP11XX_REG_MANUFACTURER_ID:
case CAP11XX_REG_REVISION:
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_RBTREE,
.volatile_reg = cap11xx_volatile_reg,
};
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)
{
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);
}
static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
const struct i2c_device_id *id)
{
struct device *dev = &i2c_client->dev;
struct cap11xx_priv *priv;
struct device_node *node;
const struct cap11xx_hw_model *cap;
int i, error, irq, gain = 0;
unsigned int val, rev;
u32 gain32;
if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
return -EINVAL;
}
cap = &cap11xx_devices[id->driver_data];
if (!cap || !cap->num_channels) {
dev_err(dev, "Invalid device configuration\n");
return -EINVAL;
}
priv = devm_kzalloc(dev,
sizeof(*priv) +
cap->num_channels * sizeof(priv->keycodes[0]),
GFP_KERNEL);
if (!priv)
return -ENOMEM;
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, revision 0x%02x\n", rev);
i2c_set_clientdata(i2c_client, priv);
node = dev->of_node;
if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {
if (is_power_of_2(gain32) && gain32 <= 8)
gain = ilog2(gain32);
else
dev_err(dev, "Invalid sensor-gain value %d\n", gain32);
}
if (of_property_read_bool(node, "microchip,irq-active-high")) {
error = regmap_update_bits(priv->regmap, CAP11XX_REG_CONFIG2,
CAP11XX_REG_CONFIG2_ALT_POL, 0);
if (error)
return error;
}
/* Provide some useful defaults */
for (i = 0; i < cap->num_channels; i++)
priv->keycodes[i] = KEY_A + i;
of_property_read_u32_array(node, "linux,keycodes",
priv->keycodes, cap->num_channels);
error = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
if (error)
return error;
/* Disable autorepeat. The Linux input system has its own handling. */
error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
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(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;
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;
irq = irq_of_parse_and_map(node, 0);
if (!irq) {
dev_err(dev, "Unable to parse or map IRQ\n");
return -ENXIO;
}
error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func,
IRQF_ONESHOT, dev_name(dev), priv);
if (error)
return error;
return 0;
}
static const struct of_device_id cap11xx_dt_ids[] = {
{ .compatible = "microchip,cap1106", },
{ .compatible = "microchip,cap1126", },
{ .compatible = "microchip,cap1188", },
{}
};
MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
static const struct i2c_device_id cap11xx_i2c_ids[] = {
{ "cap1106", CAP1106 },
{ "cap1126", CAP1126 },
{ "cap1188", CAP1188 },
{}
};
MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
static struct i2c_driver cap11xx_i2c_driver = {
.driver = {
.name = "cap11xx",
.owner = THIS_MODULE,
.of_match_table = cap11xx_dt_ids,
},
.id_table = cap11xx_i2c_ids,
.probe = cap11xx_i2c_probe,
};
module_i2c_driver(cap11xx_i2c_driver);
MODULE_ALIAS("platform:cap11xx");
MODULE_DESCRIPTION("Microchip CAP11XX driver");
MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
MODULE_LICENSE("GPL v2");
