zephyr/drivers/sensor/sx9500/sx9500.c

140 lines
3.6 KiB
C

/* sensor_sx9500.c - Driver for Semtech SX9500 SAR proximity chip */
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <kernel.h>
#include <drivers/i2c.h>
#include <drivers/sensor.h>
#include <init.h>
#include <drivers/gpio.h>
#include <sys/__assert.h>
#include <logging/log.h>
#include "sx9500.h"
LOG_MODULE_REGISTER(SX9500, CONFIG_SENSOR_LOG_LEVEL);
static u8_t sx9500_reg_defaults[] = {
/*
* First number is register address to write to. The chip
* auto-increments the address for subsequent values in a single
* write message.
*/
SX9500_REG_PROX_CTRL1,
0x43, /* Shield enabled, small range. */
0x77, /* x8 gain, 167kHz frequency, finest resolution. */
0x40, /* Doze enabled, 2x scan period doze, no raw filter. */
0x30, /* Average threshold. */
0x0f, /* Debouncer off, lowest average negative filter,
* highest average positive filter.
*/
0x0e, /* Proximity detection threshold: 280 */
0x00, /* No automatic compensation, compensate each pin
* independently, proximity hysteresis: 32, close
* debouncer off, far debouncer off.
*/
0x00, /* No stuck timeout, no periodic compensation. */
};
static int sx9500_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct sx9500_data *data = (struct sx9500_data *) dev->driver_data;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_PROX);
return i2c_reg_read_byte(data->i2c_master, data->i2c_slave_addr,
SX9500_REG_STAT, &data->prox_stat);
}
static int sx9500_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct sx9500_data *data = (struct sx9500_data *) dev->driver_data;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_PROX);
val->val1 = !!(data->prox_stat &
(1 << (4 + CONFIG_SX9500_PROX_CHANNEL)));
val->val2 = 0;
return 0;
}
static const struct sensor_driver_api sx9500_api_funcs = {
.sample_fetch = sx9500_sample_fetch,
.channel_get = sx9500_channel_get,
#ifdef CONFIG_SX9500_TRIGGER
.trigger_set = sx9500_trigger_set,
#endif
};
static int sx9500_init_chip(struct device *dev)
{
struct sx9500_data *data = (struct sx9500_data *) dev->driver_data;
u8_t val;
if (i2c_write(data->i2c_master, sx9500_reg_defaults,
sizeof(sx9500_reg_defaults), data->i2c_slave_addr)
< 0) {
return -EIO;
}
/* No interrupts active. We only activate them when an
* application registers a trigger.
*/
if (i2c_reg_write_byte(data->i2c_master, data->i2c_slave_addr,
SX9500_REG_IRQ_MSK, 0) < 0) {
return -EIO;
}
/* Read irq source reg to clear reset status. */
if (i2c_reg_read_byte(data->i2c_master, data->i2c_slave_addr,
SX9500_REG_IRQ_SRC, &val) < 0) {
return -EIO;
}
return i2c_reg_write_byte(data->i2c_master, data->i2c_slave_addr,
SX9500_REG_PROX_CTRL0,
1 << CONFIG_SX9500_PROX_CHANNEL);
}
int sx9500_init(struct device *dev)
{
struct sx9500_data *data = dev->driver_data;
data->i2c_master = device_get_binding(CONFIG_SX9500_I2C_DEV_NAME);
if (!data->i2c_master) {
LOG_DBG("sx9500: i2c master not found: %s",
CONFIG_SX9500_I2C_DEV_NAME);
return -EINVAL;
}
data->i2c_slave_addr = CONFIG_SX9500_I2C_ADDR;
if (sx9500_init_chip(dev) < 0) {
LOG_DBG("sx9500: failed to initialize chip");
return -EINVAL;
}
if (sx9500_setup_interrupt(dev) < 0) {
LOG_DBG("sx9500: failed to setup interrupt");
return -EINVAL;
}
return 0;
}
struct sx9500_data sx9500_data;
DEVICE_AND_API_INIT(sx9500, CONFIG_SX9500_DEV_NAME, sx9500_init, &sx9500_data,
NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
&sx9500_api_funcs);