zephyr/drivers/sensor/sensor_sx9500.c

148 lines
4.0 KiB
C

/* sensor_sx9500.c - Driver for Semtech SX9500 SAR proximity chip */
/*
* Copyright (c) 2016 Intel Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <nanokernel.h>
#include <i2c.h>
#include <sensor.h>
#include <init.h>
#include <gpio.h>
#include <misc/__assert.h>
#include "sensor_sx9500.h"
static uint8_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 postive 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(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(chan == SENSOR_CHAN_PROX);
val->type = SENSOR_VALUE_TYPE_INT;
val->val1 = !!(data->prox_stat &
(1 << (4 + CONFIG_SX9500_PROX_CHANNEL)));
return 0;
}
static 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;
uint8_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) {
SYS_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) {
SYS_LOG_DBG("sx9500: failed to initialize chip err %d", ret);
return -EINVAL;
}
if (sx9500_setup_interrupt(dev) < 0) {
SYS_LOG_DBG("sx9500: failed to setup interrupt err %d", ret);
return -EINVAL;
}
dev->driver_api = &sx9500_api_funcs;
return 0;
}
struct sx9500_data sx9500_data;
DEVICE_INIT(sx9500, CONFIG_SX9500_DEV_NAME, sx9500_init, &sx9500_data,
NULL, SECONDARY, CONFIG_SX9500_INIT_PRIORITY);