linux/drivers/iio/proximity/sx9500.c

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/*
* Copyright (c) 2014 Intel Corporation
*
* Driver for Semtech's SX9500 capacitive proximity/button solution.
* Datasheet available at
* <http://www.semtech.com/images/datasheet/sx9500.pdf>.
*
* 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/slab.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#define SX9500_DRIVER_NAME "sx9500"
#define SX9500_IRQ_NAME "sx9500_event"
#define SX9500_GPIO_NAME "sx9500_gpio"
/* Register definitions. */
#define SX9500_REG_IRQ_SRC 0x00
#define SX9500_REG_STAT 0x01
#define SX9500_REG_IRQ_MSK 0x03
#define SX9500_REG_PROX_CTRL0 0x06
#define SX9500_REG_PROX_CTRL1 0x07
#define SX9500_REG_PROX_CTRL2 0x08
#define SX9500_REG_PROX_CTRL3 0x09
#define SX9500_REG_PROX_CTRL4 0x0a
#define SX9500_REG_PROX_CTRL5 0x0b
#define SX9500_REG_PROX_CTRL6 0x0c
#define SX9500_REG_PROX_CTRL7 0x0d
#define SX9500_REG_PROX_CTRL8 0x0e
#define SX9500_REG_SENSOR_SEL 0x20
#define SX9500_REG_USE_MSB 0x21
#define SX9500_REG_USE_LSB 0x22
#define SX9500_REG_AVG_MSB 0x23
#define SX9500_REG_AVG_LSB 0x24
#define SX9500_REG_DIFF_MSB 0x25
#define SX9500_REG_DIFF_LSB 0x26
#define SX9500_REG_OFFSET_MSB 0x27
#define SX9500_REG_OFFSET_LSB 0x28
#define SX9500_REG_RESET 0x7f
/* Write this to REG_RESET to do a soft reset. */
#define SX9500_SOFT_RESET 0xde
#define SX9500_SCAN_PERIOD_MASK GENMASK(6, 4)
#define SX9500_SCAN_PERIOD_SHIFT 4
/*
* These serve for identifying IRQ source in the IRQ_SRC register, and
* also for masking the IRQs in the IRQ_MSK register.
*/
#define SX9500_CLOSE_IRQ BIT(6)
#define SX9500_FAR_IRQ BIT(5)
#define SX9500_CONVDONE_IRQ BIT(3)
#define SX9500_PROXSTAT_SHIFT 4
#define SX9500_NUM_CHANNELS 4
struct sx9500_data {
struct mutex mutex;
struct i2c_client *client;
struct iio_trigger *trig;
struct regmap *regmap;
/*
* Last reading of the proximity status for each channel. We
* only send an event to user space when this changes.
*/
bool prox_stat[SX9500_NUM_CHANNELS];
bool event_enabled[SX9500_NUM_CHANNELS];
bool trigger_enabled;
u16 *buffer;
};
static const struct iio_event_spec sx9500_events[] = {
{
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_EITHER,
.mask_separate = BIT(IIO_EV_INFO_ENABLE),
},
};
#define SX9500_CHANNEL(idx) \
{ \
.type = IIO_PROXIMITY, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.indexed = 1, \
.channel = idx, \
.event_spec = sx9500_events, \
.num_event_specs = ARRAY_SIZE(sx9500_events), \
.scan_index = idx, \
.scan_type = { \
.sign = 'u', \
.realbits = 16, \
.storagebits = 16, \
.shift = 0, \
}, \
}
static const struct iio_chan_spec sx9500_channels[] = {
SX9500_CHANNEL(0),
SX9500_CHANNEL(1),
SX9500_CHANNEL(2),
SX9500_CHANNEL(3),
IIO_CHAN_SOFT_TIMESTAMP(4),
};
static const struct {
int val;
int val2;
} sx9500_samp_freq_table[] = {
{33, 333333},
{16, 666666},
{11, 111111},
{8, 333333},
{6, 666666},
{5, 0},
{3, 333333},
{2, 500000},
};
static const struct regmap_range sx9500_writable_reg_ranges[] = {
regmap_reg_range(SX9500_REG_IRQ_MSK, SX9500_REG_IRQ_MSK),
regmap_reg_range(SX9500_REG_PROX_CTRL0, SX9500_REG_PROX_CTRL8),
regmap_reg_range(SX9500_REG_SENSOR_SEL, SX9500_REG_SENSOR_SEL),
regmap_reg_range(SX9500_REG_OFFSET_MSB, SX9500_REG_OFFSET_LSB),
regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
};
static const struct regmap_access_table sx9500_writeable_regs = {
.yes_ranges = sx9500_writable_reg_ranges,
.n_yes_ranges = ARRAY_SIZE(sx9500_writable_reg_ranges),
};
/*
* All allocated registers are readable, so we just list unallocated
* ones.
*/
static const struct regmap_range sx9500_non_readable_reg_ranges[] = {
regmap_reg_range(SX9500_REG_STAT + 1, SX9500_REG_STAT + 1),
regmap_reg_range(SX9500_REG_IRQ_MSK + 1, SX9500_REG_PROX_CTRL0 - 1),
regmap_reg_range(SX9500_REG_PROX_CTRL8 + 1, SX9500_REG_SENSOR_SEL - 1),
regmap_reg_range(SX9500_REG_OFFSET_LSB + 1, SX9500_REG_RESET - 1),
};
static const struct regmap_access_table sx9500_readable_regs = {
.no_ranges = sx9500_non_readable_reg_ranges,
.n_no_ranges = ARRAY_SIZE(sx9500_non_readable_reg_ranges),
};
static const struct regmap_range sx9500_volatile_reg_ranges[] = {
regmap_reg_range(SX9500_REG_IRQ_SRC, SX9500_REG_STAT),
regmap_reg_range(SX9500_REG_USE_MSB, SX9500_REG_OFFSET_LSB),
regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
};
static const struct regmap_access_table sx9500_volatile_regs = {
.yes_ranges = sx9500_volatile_reg_ranges,
.n_yes_ranges = ARRAY_SIZE(sx9500_volatile_reg_ranges),
};
static const struct regmap_config sx9500_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = SX9500_REG_RESET,
.cache_type = REGCACHE_RBTREE,
.wr_table = &sx9500_writeable_regs,
.rd_table = &sx9500_readable_regs,
.volatile_table = &sx9500_volatile_regs,
};
static int sx9500_read_proximity(struct sx9500_data *data,
const struct iio_chan_spec *chan,
int *val)
{
int ret;
__be16 regval;
ret = regmap_write(data->regmap, SX9500_REG_SENSOR_SEL, chan->channel);
if (ret < 0)
return ret;
ret = regmap_bulk_read(data->regmap, SX9500_REG_USE_MSB, &regval, 2);
if (ret < 0)
return ret;
*val = be16_to_cpu(regval);
return IIO_VAL_INT;
}
static int sx9500_read_samp_freq(struct sx9500_data *data,
int *val, int *val2)
{
int ret;
unsigned int regval;
mutex_lock(&data->mutex);
ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &regval);
mutex_unlock(&data->mutex);
if (ret < 0)
return ret;
regval = (regval & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
*val = sx9500_samp_freq_table[regval].val;
*val2 = sx9500_samp_freq_table[regval].val2;
return IIO_VAL_INT_PLUS_MICRO;
}
static int sx9500_read_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
int *val, int *val2, long mask)
{
struct sx9500_data *data = iio_priv(indio_dev);
int ret;
switch (chan->type) {
case IIO_PROXIMITY:
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
mutex_lock(&data->mutex);
ret = sx9500_read_proximity(data, chan, val);
mutex_unlock(&data->mutex);
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
return sx9500_read_samp_freq(data, val, val2);
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static int sx9500_set_samp_freq(struct sx9500_data *data,
int val, int val2)
{
int i, ret;
for (i = 0; i < ARRAY_SIZE(sx9500_samp_freq_table); i++)
if (val == sx9500_samp_freq_table[i].val &&
val2 == sx9500_samp_freq_table[i].val2)
break;
if (i == ARRAY_SIZE(sx9500_samp_freq_table))
return -EINVAL;
mutex_lock(&data->mutex);
ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
SX9500_SCAN_PERIOD_MASK,
i << SX9500_SCAN_PERIOD_SHIFT);
mutex_unlock(&data->mutex);
return ret;
}
static int sx9500_write_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
int val, int val2, long mask)
{
struct sx9500_data *data = iio_priv(indio_dev);
switch (chan->type) {
case IIO_PROXIMITY:
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
return sx9500_set_samp_freq(data, val, val2);
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static irqreturn_t sx9500_irq_handler(int irq, void *private)
{
struct iio_dev *indio_dev = private;
struct sx9500_data *data = iio_priv(indio_dev);
if (data->trigger_enabled)
iio_trigger_poll(data->trig);
/*
* Even if no event is enabled, we need to wake the thread to
* clear the interrupt state by reading SX9500_REG_IRQ_SRC. It
* is not possible to do that here because regmap_read takes a
* mutex.
*/
return IRQ_WAKE_THREAD;
}
static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
{
struct iio_dev *indio_dev = private;
struct sx9500_data *data = iio_priv(indio_dev);
int ret;
unsigned int val, chan;
mutex_lock(&data->mutex);
ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
if (ret < 0) {
dev_err(&data->client->dev, "i2c transfer error in irq\n");
goto out;
}
if (!(val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ)))
goto out;
ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
if (ret < 0) {
dev_err(&data->client->dev, "i2c transfer error in irq\n");
goto out;
}
val >>= SX9500_PROXSTAT_SHIFT;
for (chan = 0; chan < SX9500_NUM_CHANNELS; chan++) {
int dir;
u64 ev;
bool new_prox = val & BIT(chan);
if (!data->event_enabled[chan])
continue;
if (new_prox == data->prox_stat[chan])
/* No change on this channel. */
continue;
dir = new_prox ? IIO_EV_DIR_FALLING :
IIO_EV_DIR_RISING;
ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY,
chan,
IIO_EV_TYPE_THRESH,
dir);
iio_push_event(indio_dev, ev, iio_get_time_ns());
data->prox_stat[chan] = new_prox;
}
out:
mutex_unlock(&data->mutex);
return IRQ_HANDLED;
}
static int sx9500_read_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir)
{
struct sx9500_data *data = iio_priv(indio_dev);
if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
dir != IIO_EV_DIR_EITHER)
return -EINVAL;
return data->event_enabled[chan->channel];
}
static int sx9500_write_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
int state)
{
struct sx9500_data *data = iio_priv(indio_dev);
int ret, i;
bool any_active = false;
unsigned int irqmask;
if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
dir != IIO_EV_DIR_EITHER)
return -EINVAL;
mutex_lock(&data->mutex);
data->event_enabled[chan->channel] = state;
for (i = 0; i < SX9500_NUM_CHANNELS; i++)
if (data->event_enabled[i]) {
any_active = true;
break;
}
irqmask = SX9500_CLOSE_IRQ | SX9500_FAR_IRQ;
if (any_active)
ret = regmap_update_bits(data->regmap, SX9500_REG_IRQ_MSK,
irqmask, irqmask);
else
ret = regmap_update_bits(data->regmap, SX9500_REG_IRQ_MSK,
irqmask, 0);
mutex_unlock(&data->mutex);
return ret;
}
static int sx9500_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
struct sx9500_data *data = iio_priv(indio_dev);
mutex_lock(&data->mutex);
kfree(data->buffer);
data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
mutex_unlock(&data->mutex);
if (data->buffer == NULL)
return -ENOMEM;
return 0;
}
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
"2.500000 3.333333 5 6.666666 8.333333 11.111111 16.666666 33.333333");
static struct attribute *sx9500_attributes[] = {
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
static const struct attribute_group sx9500_attribute_group = {
.attrs = sx9500_attributes,
};
static const struct iio_info sx9500_info = {
.driver_module = THIS_MODULE,
.attrs = &sx9500_attribute_group,
.read_raw = &sx9500_read_raw,
.write_raw = &sx9500_write_raw,
.read_event_config = &sx9500_read_event_config,
.write_event_config = &sx9500_write_event_config,
.update_scan_mode = &sx9500_update_scan_mode,
};
static int sx9500_set_trigger_state(struct iio_trigger *trig,
bool state)
{
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct sx9500_data *data = iio_priv(indio_dev);
int ret;
mutex_lock(&data->mutex);
ret = regmap_update_bits(data->regmap, SX9500_REG_IRQ_MSK,
SX9500_CONVDONE_IRQ,
state ? SX9500_CONVDONE_IRQ : 0);
if (ret == 0)
data->trigger_enabled = state;
mutex_unlock(&data->mutex);
return ret;
}
static const struct iio_trigger_ops sx9500_trigger_ops = {
.set_trigger_state = sx9500_set_trigger_state,
.owner = THIS_MODULE,
};
static irqreturn_t sx9500_trigger_handler(int irq, void *private)
{
struct iio_poll_func *pf = private;
struct iio_dev *indio_dev = pf->indio_dev;
struct sx9500_data *data = iio_priv(indio_dev);
int val, bit, ret, i = 0;
mutex_lock(&data->mutex);
for_each_set_bit(bit, indio_dev->active_scan_mask,
indio_dev->masklength) {
ret = sx9500_read_proximity(data, &indio_dev->channels[bit],
&val);
if (ret < 0)
goto out;
data->buffer[i++] = val;
}
iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
iio_get_time_ns());
out:
mutex_unlock(&data->mutex);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
struct sx9500_reg_default {
u8 reg;
u8 def;
};
static const struct sx9500_reg_default sx9500_default_regs[] = {
{
.reg = SX9500_REG_PROX_CTRL1,
/* Shield enabled, small range. */
.def = 0x43,
},
{
.reg = SX9500_REG_PROX_CTRL2,
/* x8 gain, 167kHz frequency, finest resolution. */
.def = 0x77,
},
{
.reg = SX9500_REG_PROX_CTRL3,
/* Doze enabled, 2x scan period doze, no raw filter. */
.def = 0x40,
},
{
.reg = SX9500_REG_PROX_CTRL4,
/* Average threshold. */
.def = 0x30,
},
{
.reg = SX9500_REG_PROX_CTRL5,
/*
* Debouncer off, lowest average negative filter,
* highest average postive filter.
*/
.def = 0x0f,
},
{
.reg = SX9500_REG_PROX_CTRL6,
/* Proximity detection threshold: 280 */
.def = 0x0e,
},
{
.reg = SX9500_REG_PROX_CTRL7,
/*
* No automatic compensation, compensate each pin
* independently, proximity hysteresis: 32, close
* debouncer off, far debouncer off.
*/
.def = 0x00,
},
{
.reg = SX9500_REG_PROX_CTRL8,
/* No stuck timeout, no periodic compensation. */
.def = 0x00,
},
{
.reg = SX9500_REG_PROX_CTRL0,
/* Scan period: 30ms, all sensors enabled. */
.def = 0x0f,
},
};
static int sx9500_init_device(struct iio_dev *indio_dev)
{
struct sx9500_data *data = iio_priv(indio_dev);
int ret, i;
unsigned int val;
ret = regmap_write(data->regmap, SX9500_REG_IRQ_MSK, 0);
if (ret < 0)
return ret;
ret = regmap_write(data->regmap, SX9500_REG_RESET,
SX9500_SOFT_RESET);
if (ret < 0)
return ret;
ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
if (ret < 0)
return ret;
for (i = 0; i < ARRAY_SIZE(sx9500_default_regs); i++) {
ret = regmap_write(data->regmap,
sx9500_default_regs[i].reg,
sx9500_default_regs[i].def);
if (ret < 0)
return ret;
}
return 0;
}
static int sx9500_gpio_probe(struct i2c_client *client,
struct sx9500_data *data)
{
struct device *dev;
struct gpio_desc *gpio;
int ret;
if (!client)
return -EINVAL;
dev = &client->dev;
/* data ready gpio interrupt pin */
gpio = devm_gpiod_get_index(dev, SX9500_GPIO_NAME, 0, GPIOD_IN);
if (IS_ERR(gpio)) {
dev_err(dev, "acpi gpio get index failed\n");
return PTR_ERR(gpio);
}
ret = gpiod_to_irq(gpio);
dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
return ret;
}
static int sx9500_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct sx9500_data *data;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (indio_dev == NULL)
return -ENOMEM;
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->mutex);
data->trigger_enabled = false;
data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
if (IS_ERR(data->regmap))
return PTR_ERR(data->regmap);
sx9500_init_device(indio_dev);
indio_dev->dev.parent = &client->dev;
indio_dev->name = SX9500_DRIVER_NAME;
indio_dev->channels = sx9500_channels;
indio_dev->num_channels = ARRAY_SIZE(sx9500_channels);
indio_dev->info = &sx9500_info;
indio_dev->modes = INDIO_DIRECT_MODE;
i2c_set_clientdata(client, indio_dev);
if (client->irq <= 0)
client->irq = sx9500_gpio_probe(client, data);
if (client->irq > 0) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
sx9500_irq_handler, sx9500_irq_thread_handler,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
SX9500_IRQ_NAME, indio_dev);
if (ret < 0)
return ret;
data->trig = devm_iio_trigger_alloc(&client->dev,
"%s-dev%d", indio_dev->name, indio_dev->id);
if (!data->trig)
return -ENOMEM;
data->trig->dev.parent = &client->dev;
data->trig->ops = &sx9500_trigger_ops;
iio_trigger_set_drvdata(data->trig, indio_dev);
ret = iio_trigger_register(data->trig);
if (ret)
return ret;
}
ret = iio_triggered_buffer_setup(indio_dev, NULL,
sx9500_trigger_handler, NULL);
if (ret < 0)
goto out_trigger_unregister;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto out_buffer_cleanup;
return 0;
out_buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
out_trigger_unregister:
if (client->irq > 0)
iio_trigger_unregister(data->trig);
return ret;
}
static int sx9500_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct sx9500_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
if (client->irq > 0)
iio_trigger_unregister(data->trig);
kfree(data->buffer);
return 0;
}
static const struct acpi_device_id sx9500_acpi_match[] = {
{"SSX9500", 0},
{ },
};
MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);
static const struct i2c_device_id sx9500_id[] = {
{"sx9500", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, sx9500_id);
static struct i2c_driver sx9500_driver = {
.driver = {
.name = SX9500_DRIVER_NAME,
.acpi_match_table = ACPI_PTR(sx9500_acpi_match),
},
.probe = sx9500_probe,
.remove = sx9500_remove,
.id_table = sx9500_id,
};
module_i2c_driver(sx9500_driver);
MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
MODULE_DESCRIPTION("Driver for Semtech SX9500 proximity sensor");
MODULE_LICENSE("GPL v2");