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alistair23-linux/drivers/iio/adc/hi8435.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Holt Integrated Circuits HI-8435 threshold detector driver
*
* Copyright (C) 2015 Zodiac Inflight Innovations
* Copyright (C) 2015 Cogent Embedded, Inc.
*/
#include <linux/delay.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_event.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/spi/spi.h>
#include <linux/gpio/consumer.h>
#define DRV_NAME "hi8435"
/* Register offsets for HI-8435 */
#define HI8435_CTRL_REG 0x02
#define HI8435_PSEN_REG 0x04
#define HI8435_TMDATA_REG 0x1E
#define HI8435_GOCENHYS_REG 0x3A
#define HI8435_SOCENHYS_REG 0x3C
#define HI8435_SO7_0_REG 0x10
#define HI8435_SO15_8_REG 0x12
#define HI8435_SO23_16_REG 0x14
#define HI8435_SO31_24_REG 0x16
#define HI8435_SO31_0_REG 0x78
#define HI8435_WRITE_OPCODE 0x00
#define HI8435_READ_OPCODE 0x80
/* CTRL register bits */
#define HI8435_CTRL_TEST 0x01
#define HI8435_CTRL_SRST 0x02
struct hi8435_priv {
struct spi_device *spi;
struct mutex lock;
unsigned long event_scan_mask; /* soft mask/unmask channels events */
unsigned int event_prev_val;
unsigned threshold_lo[2]; /* GND-Open and Supply-Open thresholds */
unsigned threshold_hi[2]; /* GND-Open and Supply-Open thresholds */
u8 reg_buffer[3] ____cacheline_aligned;
};
static int hi8435_readb(struct hi8435_priv *priv, u8 reg, u8 *val)
{
reg |= HI8435_READ_OPCODE;
return spi_write_then_read(priv->spi, &reg, 1, val, 1);
}
static int hi8435_readw(struct hi8435_priv *priv, u8 reg, u16 *val)
{
int ret;
__be16 be_val;
reg |= HI8435_READ_OPCODE;
ret = spi_write_then_read(priv->spi, &reg, 1, &be_val, 2);
*val = be16_to_cpu(be_val);
return ret;
}
static int hi8435_readl(struct hi8435_priv *priv, u8 reg, u32 *val)
{
int ret;
__be32 be_val;
reg |= HI8435_READ_OPCODE;
ret = spi_write_then_read(priv->spi, &reg, 1, &be_val, 4);
*val = be32_to_cpu(be_val);
return ret;
}
static int hi8435_writeb(struct hi8435_priv *priv, u8 reg, u8 val)
{
priv->reg_buffer[0] = reg | HI8435_WRITE_OPCODE;
priv->reg_buffer[1] = val;
return spi_write(priv->spi, priv->reg_buffer, 2);
}
static int hi8435_writew(struct hi8435_priv *priv, u8 reg, u16 val)
{
priv->reg_buffer[0] = reg | HI8435_WRITE_OPCODE;
priv->reg_buffer[1] = (val >> 8) & 0xff;
priv->reg_buffer[2] = val & 0xff;
return spi_write(priv->spi, priv->reg_buffer, 3);
}
static int hi8435_read_raw(struct iio_dev *idev,
const struct iio_chan_spec *chan,
int *val, int *val2, long mask)
{
struct hi8435_priv *priv = iio_priv(idev);
u32 tmp;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = hi8435_readl(priv, HI8435_SO31_0_REG, &tmp);
if (ret < 0)
return ret;
*val = !!(tmp & BIT(chan->channel));
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int hi8435_read_event_config(struct iio_dev *idev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir)
{
struct hi8435_priv *priv = iio_priv(idev);
return !!(priv->event_scan_mask & BIT(chan->channel));
}
static int hi8435_write_event_config(struct iio_dev *idev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir, int state)
{
struct hi8435_priv *priv = iio_priv(idev);
int ret;
u32 tmp;
if (state) {
ret = hi8435_readl(priv, HI8435_SO31_0_REG, &tmp);
if (ret < 0)
return ret;
if (tmp & BIT(chan->channel))
priv->event_prev_val |= BIT(chan->channel);
else
priv->event_prev_val &= ~BIT(chan->channel);
priv->event_scan_mask |= BIT(chan->channel);
} else
priv->event_scan_mask &= ~BIT(chan->channel);
return 0;
}
static int hi8435_read_event_value(struct iio_dev *idev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
enum iio_event_info info,
int *val, int *val2)
{
struct hi8435_priv *priv = iio_priv(idev);
int ret;
u8 mode, psen;
u16 reg;
ret = hi8435_readb(priv, HI8435_PSEN_REG, &psen);
if (ret < 0)
return ret;
/* Supply-Open or GND-Open sensing mode */
mode = !!(psen & BIT(chan->channel / 8));
ret = hi8435_readw(priv, mode ? HI8435_SOCENHYS_REG :
HI8435_GOCENHYS_REG, &reg);
if (ret < 0)
return ret;
if (dir == IIO_EV_DIR_FALLING)
*val = ((reg & 0xff) - (reg >> 8)) / 2;
else if (dir == IIO_EV_DIR_RISING)
*val = ((reg & 0xff) + (reg >> 8)) / 2;
return IIO_VAL_INT;
}
static int hi8435_write_event_value(struct iio_dev *idev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
enum iio_event_info info,
int val, int val2)
{
struct hi8435_priv *priv = iio_priv(idev);
int ret;
u8 mode, psen;
u16 reg;
ret = hi8435_readb(priv, HI8435_PSEN_REG, &psen);
if (ret < 0)
return ret;
/* Supply-Open or GND-Open sensing mode */
mode = !!(psen & BIT(chan->channel / 8));
ret = hi8435_readw(priv, mode ? HI8435_SOCENHYS_REG :
HI8435_GOCENHYS_REG, &reg);
if (ret < 0)
return ret;
if (dir == IIO_EV_DIR_FALLING) {
/* falling threshold range 2..21V, hysteresis minimum 2V */
if (val < 2 || val > 21 || (val + 2) > priv->threshold_hi[mode])
return -EINVAL;
if (val == priv->threshold_lo[mode])
return 0;
priv->threshold_lo[mode] = val;
/* hysteresis must not be odd */
if ((priv->threshold_hi[mode] - priv->threshold_lo[mode]) % 2)
priv->threshold_hi[mode]--;
} else if (dir == IIO_EV_DIR_RISING) {
/* rising threshold range 3..22V, hysteresis minimum 2V */
if (val < 3 || val > 22 || val < (priv->threshold_lo[mode] + 2))
return -EINVAL;
if (val == priv->threshold_hi[mode])
return 0;
priv->threshold_hi[mode] = val;
/* hysteresis must not be odd */
if ((priv->threshold_hi[mode] - priv->threshold_lo[mode]) % 2)
priv->threshold_lo[mode]++;
}
/* program thresholds */
mutex_lock(&priv->lock);
ret = hi8435_readw(priv, mode ? HI8435_SOCENHYS_REG :
HI8435_GOCENHYS_REG, &reg);
if (ret < 0) {
mutex_unlock(&priv->lock);
return ret;
}
/* hysteresis */
reg = priv->threshold_hi[mode] - priv->threshold_lo[mode];
reg <<= 8;
/* threshold center */
reg |= (priv->threshold_hi[mode] + priv->threshold_lo[mode]);
ret = hi8435_writew(priv, mode ? HI8435_SOCENHYS_REG :
HI8435_GOCENHYS_REG, reg);
mutex_unlock(&priv->lock);
return ret;
}
static int hi8435_debugfs_reg_access(struct iio_dev *idev,
unsigned reg, unsigned writeval,
unsigned *readval)
{
struct hi8435_priv *priv = iio_priv(idev);
int ret;
u8 val;
if (readval != NULL) {
ret = hi8435_readb(priv, reg, &val);
*readval = val;
} else {
val = (u8)writeval;
ret = hi8435_writeb(priv, reg, val);
}
return ret;
}
static const struct iio_event_spec hi8435_events[] = {
{
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_RISING,
.mask_separate = BIT(IIO_EV_INFO_VALUE),
}, {
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_FALLING,
.mask_separate = BIT(IIO_EV_INFO_VALUE),
}, {
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_EITHER,
.mask_separate = BIT(IIO_EV_INFO_ENABLE),
},
};
static int hi8435_get_sensing_mode(struct iio_dev *idev,
const struct iio_chan_spec *chan)
{
struct hi8435_priv *priv = iio_priv(idev);
int ret;
u8 reg;
ret = hi8435_readb(priv, HI8435_PSEN_REG, &reg);
if (ret < 0)
return ret;
return !!(reg & BIT(chan->channel / 8));
}
static int hi8435_set_sensing_mode(struct iio_dev *idev,
const struct iio_chan_spec *chan,
unsigned int mode)
{
struct hi8435_priv *priv = iio_priv(idev);
int ret;
u8 reg;
mutex_lock(&priv->lock);
ret = hi8435_readb(priv, HI8435_PSEN_REG, &reg);
if (ret < 0) {
mutex_unlock(&priv->lock);
return ret;
}
reg &= ~BIT(chan->channel / 8);
if (mode)
reg |= BIT(chan->channel / 8);
ret = hi8435_writeb(priv, HI8435_PSEN_REG, reg);
mutex_unlock(&priv->lock);
return ret;
}
static const char * const hi8435_sensing_modes[] = { "GND-Open",
"Supply-Open" };
static const struct iio_enum hi8435_sensing_mode = {
.items = hi8435_sensing_modes,
.num_items = ARRAY_SIZE(hi8435_sensing_modes),
.get = hi8435_get_sensing_mode,
.set = hi8435_set_sensing_mode,
};
static const struct iio_chan_spec_ext_info hi8435_ext_info[] = {
IIO_ENUM("sensing_mode", IIO_SEPARATE, &hi8435_sensing_mode),
IIO_ENUM_AVAILABLE("sensing_mode", &hi8435_sensing_mode),
{},
};
#define HI8435_VOLTAGE_CHANNEL(num) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = num, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.event_spec = hi8435_events, \
.num_event_specs = ARRAY_SIZE(hi8435_events), \
.ext_info = hi8435_ext_info, \
}
static const struct iio_chan_spec hi8435_channels[] = {
HI8435_VOLTAGE_CHANNEL(0),
HI8435_VOLTAGE_CHANNEL(1),
HI8435_VOLTAGE_CHANNEL(2),
HI8435_VOLTAGE_CHANNEL(3),
HI8435_VOLTAGE_CHANNEL(4),
HI8435_VOLTAGE_CHANNEL(5),
HI8435_VOLTAGE_CHANNEL(6),
HI8435_VOLTAGE_CHANNEL(7),
HI8435_VOLTAGE_CHANNEL(8),
HI8435_VOLTAGE_CHANNEL(9),
HI8435_VOLTAGE_CHANNEL(10),
HI8435_VOLTAGE_CHANNEL(11),
HI8435_VOLTAGE_CHANNEL(12),
HI8435_VOLTAGE_CHANNEL(13),
HI8435_VOLTAGE_CHANNEL(14),
HI8435_VOLTAGE_CHANNEL(15),
HI8435_VOLTAGE_CHANNEL(16),
HI8435_VOLTAGE_CHANNEL(17),
HI8435_VOLTAGE_CHANNEL(18),
HI8435_VOLTAGE_CHANNEL(19),
HI8435_VOLTAGE_CHANNEL(20),
HI8435_VOLTAGE_CHANNEL(21),
HI8435_VOLTAGE_CHANNEL(22),
HI8435_VOLTAGE_CHANNEL(23),
HI8435_VOLTAGE_CHANNEL(24),
HI8435_VOLTAGE_CHANNEL(25),
HI8435_VOLTAGE_CHANNEL(26),
HI8435_VOLTAGE_CHANNEL(27),
HI8435_VOLTAGE_CHANNEL(28),
HI8435_VOLTAGE_CHANNEL(29),
HI8435_VOLTAGE_CHANNEL(30),
HI8435_VOLTAGE_CHANNEL(31),
IIO_CHAN_SOFT_TIMESTAMP(32),
};
static const struct iio_info hi8435_info = {
.read_raw = hi8435_read_raw,
.read_event_config = hi8435_read_event_config,
.write_event_config = hi8435_write_event_config,
.read_event_value = hi8435_read_event_value,
.write_event_value = hi8435_write_event_value,
.debugfs_reg_access = hi8435_debugfs_reg_access,
};
static void hi8435_iio_push_event(struct iio_dev *idev, unsigned int val)
{
struct hi8435_priv *priv = iio_priv(idev);
enum iio_event_direction dir;
unsigned int i;
unsigned int status = priv->event_prev_val ^ val;
if (!status)
return;
for_each_set_bit(i, &priv->event_scan_mask, 32) {
if (status & BIT(i)) {
dir = val & BIT(i) ? IIO_EV_DIR_RISING :
IIO_EV_DIR_FALLING;
iio_push_event(idev,
IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
IIO_EV_TYPE_THRESH, dir),
iio_get_time_ns(idev));
}
}
priv->event_prev_val = val;
}
static irqreturn_t hi8435_trigger_handler(int irq, void *private)
{
struct iio_poll_func *pf = private;
struct iio_dev *idev = pf->indio_dev;
struct hi8435_priv *priv = iio_priv(idev);
u32 val;
int ret;
ret = hi8435_readl(priv, HI8435_SO31_0_REG, &val);
if (ret < 0)
goto err_read;
hi8435_iio_push_event(idev, val);
err_read:
iio_trigger_notify_done(idev->trig);
return IRQ_HANDLED;
}
static int hi8435_probe(struct spi_device *spi)
{
struct iio_dev *idev;
struct hi8435_priv *priv;
struct gpio_desc *reset_gpio;
int ret;
idev = devm_iio_device_alloc(&spi->dev, sizeof(*priv));
if (!idev)
return -ENOMEM;
priv = iio_priv(idev);
priv->spi = spi;
reset_gpio = devm_gpiod_get(&spi->dev, NULL, GPIOD_OUT_LOW);
if (IS_ERR(reset_gpio)) {
/* chip s/w reset if h/w reset failed */
hi8435_writeb(priv, HI8435_CTRL_REG, HI8435_CTRL_SRST);
hi8435_writeb(priv, HI8435_CTRL_REG, 0);
} else {
udelay(5);
gpiod_set_value(reset_gpio, 1);
}
spi_set_drvdata(spi, idev);
mutex_init(&priv->lock);
idev->dev.parent = &spi->dev;
idev->dev.of_node = spi->dev.of_node;
idev->name = spi_get_device_id(spi)->name;
idev->modes = INDIO_DIRECT_MODE;
idev->info = &hi8435_info;
idev->channels = hi8435_channels;
idev->num_channels = ARRAY_SIZE(hi8435_channels);
/* unmask all events */
priv->event_scan_mask = ~(0);
/*
* There is a restriction in the chip - the hysteresis can not be odd.
* If the hysteresis is set to odd value then chip gets into lock state
* and not functional anymore.
* After chip reset the thresholds are in undefined state, so we need to
* initialize thresholds to some initial values and then prevent
* userspace setting odd hysteresis.
*
* Set threshold low voltage to 2V, threshold high voltage to 4V
* for both GND-Open and Supply-Open sensing modes.
*/
priv->threshold_lo[0] = priv->threshold_lo[1] = 2;
priv->threshold_hi[0] = priv->threshold_hi[1] = 4;
hi8435_writew(priv, HI8435_GOCENHYS_REG, 0x206);
hi8435_writew(priv, HI8435_SOCENHYS_REG, 0x206);
ret = iio_triggered_event_setup(idev, NULL, hi8435_trigger_handler);
if (ret)
return ret;
ret = iio_device_register(idev);
if (ret < 0) {
dev_err(&spi->dev, "unable to register device\n");
goto unregister_triggered_event;
}
return 0;
unregister_triggered_event:
iio_triggered_event_cleanup(idev);
return ret;
}
static int hi8435_remove(struct spi_device *spi)
{
struct iio_dev *idev = spi_get_drvdata(spi);
iio_device_unregister(idev);
iio_triggered_event_cleanup(idev);
return 0;
}
static const struct of_device_id hi8435_dt_ids[] = {
{ .compatible = "holt,hi8435" },
{},
};
MODULE_DEVICE_TABLE(of, hi8435_dt_ids);
static const struct spi_device_id hi8435_id[] = {
{ "hi8435", 0},
{ }
};
MODULE_DEVICE_TABLE(spi, hi8435_id);
static struct spi_driver hi8435_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = of_match_ptr(hi8435_dt_ids),
},
.probe = hi8435_probe,
.remove = hi8435_remove,
.id_table = hi8435_id,
};
module_spi_driver(hi8435_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vladimir Barinov");
MODULE_DESCRIPTION("HI-8435 threshold detector");
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