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// SPDX-License-Identifier: GPL-2.0-only
/*
* STMicroelectronics uvis25 sensor driver
*
* Copyright 2017 STMicroelectronics Inc.
*
* Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/iio/sysfs.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/buffer.h>
#include <linux/regmap.h>
#include "st_uvis25.h"
#define ST_UVIS25_REG_WHOAMI_ADDR 0x0f
#define ST_UVIS25_REG_WHOAMI_VAL 0xca
#define ST_UVIS25_REG_CTRL1_ADDR 0x20
#define ST_UVIS25_REG_ODR_MASK BIT(0)
#define ST_UVIS25_REG_BDU_MASK BIT(1)
#define ST_UVIS25_REG_CTRL2_ADDR 0x21
#define ST_UVIS25_REG_BOOT_MASK BIT(7)
#define ST_UVIS25_REG_CTRL3_ADDR 0x22
#define ST_UVIS25_REG_HL_MASK BIT(7)
#define ST_UVIS25_REG_STATUS_ADDR 0x27
#define ST_UVIS25_REG_UV_DA_MASK BIT(0)
#define ST_UVIS25_REG_OUT_ADDR 0x28
static const struct iio_chan_spec st_uvis25_channels[] = {
{
.type = IIO_UVINDEX,
.address = ST_UVIS25_REG_OUT_ADDR,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.scan_index = 0,
.scan_type = {
.sign = 'u',
.realbits = 8,
.storagebits = 8,
},
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
static int st_uvis25_check_whoami(struct st_uvis25_hw *hw)
{
int err, data;
err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data);
if (err < 0) {
dev_err(regmap_get_device(hw->regmap),
"failed to read whoami register\n");
return err;
}
if (data != ST_UVIS25_REG_WHOAMI_VAL) {
dev_err(regmap_get_device(hw->regmap),
"wrong whoami {%02x vs %02x}\n",
data, ST_UVIS25_REG_WHOAMI_VAL);
return -ENODEV;
}
return 0;
}
static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable)
{
int err;
err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
ST_UVIS25_REG_ODR_MASK, enable);
if (err < 0)
return err;
hw->enabled = enable;
return 0;
}
static int st_uvis25_read_oneshot(struct st_uvis25_hw *hw, u8 addr, int *val)
{
int err;
err = st_uvis25_set_enable(hw, true);
if (err < 0)
return err;
msleep(1500);
/*
* in order to avoid possible race conditions with interrupt
* generation, disable the sensor first and then poll output
* register. That sequence guarantees the interrupt will be reset
* when irq line is unmasked
*/
err = st_uvis25_set_enable(hw, false);
if (err < 0)
return err;
err = regmap_read(hw->regmap, addr, val);
return err < 0 ? err : IIO_VAL_INT;
}
static int st_uvis25_read_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *ch,
int *val, int *val2, long mask)
{
int ret;
ret = iio_device_claim_direct_mode(iio_dev);
if (ret)
return ret;
switch (mask) {
case IIO_CHAN_INFO_PROCESSED: {
struct st_uvis25_hw *hw = iio_priv(iio_dev);
/*
* mask irq line during oneshot read since the sensor
* does not export the capability to disable data-ready line
* in the register map and it is enabled by default.
* If the line is unmasked during read_raw() it will be set
* active and never reset since the trigger is disabled
*/
if (hw->irq > 0)
disable_irq(hw->irq);
ret = st_uvis25_read_oneshot(hw, ch->address, val);
if (hw->irq > 0)
enable_irq(hw->irq);
break;
}
default:
ret = -EINVAL;
break;
}
iio_device_release_direct_mode(iio_dev);
return ret;
}
static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private)
{
struct st_uvis25_hw *hw = private;
int err, status;
err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status);
if (err < 0)
return IRQ_HANDLED;
if (!(status & ST_UVIS25_REG_UV_DA_MASK))
return IRQ_NONE;
iio_trigger_poll_chained(hw->trig);
return IRQ_HANDLED;
}
static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev)
{
struct st_uvis25_hw *hw = iio_priv(iio_dev);
struct device *dev = regmap_get_device(hw->regmap);
bool irq_active_low = false;
unsigned long irq_type;
int err;
irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
switch (irq_type) {
case IRQF_TRIGGER_HIGH:
case IRQF_TRIGGER_RISING:
break;
case IRQF_TRIGGER_LOW:
case IRQF_TRIGGER_FALLING:
irq_active_low = true;
break;
default:
dev_info(dev, "mode %lx unsupported\n", irq_type);
return -EINVAL;
}
err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
ST_UVIS25_REG_HL_MASK, irq_active_low);
if (err < 0)
return err;
err = devm_request_threaded_irq(dev, hw->irq, NULL,
st_uvis25_trigger_handler_thread,
irq_type | IRQF_ONESHOT,
iio_dev->name, hw);
if (err) {
dev_err(dev, "failed to request trigger irq %d\n",
hw->irq);
return err;
}
hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
iio_dev->name);
if (!hw->trig)
return -ENOMEM;
iio_trigger_set_drvdata(hw->trig, iio_dev);
return devm_iio_trigger_register(dev, hw->trig);
}
static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
{
return st_uvis25_set_enable(iio_priv(iio_dev), true);
}
static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
{
return st_uvis25_set_enable(iio_priv(iio_dev), false);
}
static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
.preenable = st_uvis25_buffer_preenable,
.postdisable = st_uvis25_buffer_postdisable,
};
static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *iio_dev = pf->indio_dev;
struct st_uvis25_hw *hw = iio_priv(iio_dev);
unsigned int val;
int err;
err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val);
if (err < 0)
goto out;
hw->scan.chan = val;
iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
iio_get_time_ns(iio_dev));
out:
iio_trigger_notify_done(hw->trig);
return IRQ_HANDLED;
}
static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
{
struct st_uvis25_hw *hw = iio_priv(iio_dev);
return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
iio_dev, NULL,
st_uvis25_buffer_handler_thread,
&st_uvis25_buffer_ops);
}
static const struct iio_info st_uvis25_info = {
.read_raw = st_uvis25_read_raw,
};
static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
{
int err;
err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
ST_UVIS25_REG_BOOT_MASK, 1);
if (err < 0)
return err;
msleep(2000);
return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
ST_UVIS25_REG_BDU_MASK, 1);
}
int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap)
{
struct st_uvis25_hw *hw;
struct iio_dev *iio_dev;
int err;
iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
if (!iio_dev)
return -ENOMEM;
dev_set_drvdata(dev, (void *)iio_dev);
hw = iio_priv(iio_dev);
hw->irq = irq;
hw->regmap = regmap;
err = st_uvis25_check_whoami(hw);
if (err < 0)
return err;
iio_dev->modes = INDIO_DIRECT_MODE;
iio_dev->channels = st_uvis25_channels;
iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
iio_dev->name = ST_UVIS25_DEV_NAME;
iio_dev->info = &st_uvis25_info;
err = st_uvis25_init_sensor(hw);
if (err < 0)
return err;
if (hw->irq > 0) {
err = st_uvis25_allocate_buffer(iio_dev);
if (err < 0)
return err;
err = st_uvis25_allocate_trigger(iio_dev);
if (err)
return err;
}
return devm_iio_device_register(dev, iio_dev);
}
EXPORT_SYMBOL(st_uvis25_probe);
static int __maybe_unused st_uvis25_suspend(struct device *dev)
{
struct iio_dev *iio_dev = dev_get_drvdata(dev);
struct st_uvis25_hw *hw = iio_priv(iio_dev);
return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
ST_UVIS25_REG_ODR_MASK, 0);
}
static int __maybe_unused st_uvis25_resume(struct device *dev)
{
struct iio_dev *iio_dev = dev_get_drvdata(dev);
struct st_uvis25_hw *hw = iio_priv(iio_dev);
if (hw->enabled)
return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
ST_UVIS25_REG_ODR_MASK, 1);
return 0;
}
const struct dev_pm_ops st_uvis25_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(st_uvis25_suspend, st_uvis25_resume)
};
EXPORT_SYMBOL(st_uvis25_pm_ops);
MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
MODULE_LICENSE("GPL v2");
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