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iio: sps30: separate core and interface specific code

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Move code responsible for handling i2c communication to a separate file.
Rationale for this change is preparation for adding support for serial
communication.

Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Tomasz Duszynski 2021-05-03 08:00:12 +02:00 committed by Jonathan Cameron
parent 101af4c20c
commit 8f3f130852
6 changed files with 357 additions and 229 deletions
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1
MAINTAINERS
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@ -16484,6 +16484,7 @@ M: Tomasz Duszynski <tduszyns@gmail.com>
S: Maintained S: Maintained
F: Documentation/devicetree/bindings/iio/chemical/sensirion,sps30.yaml F: Documentation/devicetree/bindings/iio/chemical/sensirion,sps30.yaml
F: drivers/iio/chemical/sps30.c F: drivers/iio/chemical/sps30.c
F: drivers/iio/chemical/sps30_i2c.c
SERIAL DEVICE BUS SERIAL DEVICE BUS
M: Rob Herring <robh@kernel.org> M: Rob Herring <robh@kernel.org>

16
drivers/iio/chemical/Kconfig
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@ -132,17 +132,21 @@ config SENSIRION_SGP30
module will be called sgp30. module will be called sgp30.
config SPS30 config SPS30
tristate "SPS30 particulate matter sensor" tristate
depends on I2C
select CRC8
select IIO_BUFFER select IIO_BUFFER
select IIO_TRIGGERED_BUFFER select IIO_TRIGGERED_BUFFER
config SPS30_I2C
tristate "SPS30 particulate matter sensor I2C driver"
depends on I2C
select SPS30
select CRC8
help help
Say Y here to build support for the Sensirion SPS30 particulate Say Y here to build support for the Sensirion SPS30 I2C interface
matter sensor. driver.
To compile this driver as a module, choose M here: the module will To compile this driver as a module, choose M here: the module will
be called sps30. be called sps30_i2c.
config VZ89X config VZ89X
tristate "SGX Sensortech MiCS VZ89X VOC sensor" tristate "SGX Sensortech MiCS VZ89X VOC sensor"

1
drivers/iio/chemical/Makefile
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@ -17,4 +17,5 @@ obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o
obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o
obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o
obj-$(CONFIG_SPS30) += sps30.o obj-$(CONFIG_SPS30) += sps30.o
obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
obj-$(CONFIG_VZ89X) += vz89x.o obj-$(CONFIG_VZ89X) += vz89x.o

275
drivers/iio/chemical/sps30.c
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@ -3,11 +3,8 @@
* Sensirion SPS30 particulate matter sensor driver * Sensirion SPS30 particulate matter sensor driver
* *
* Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
*
* I2C slave address: 0x69
*/ */
#include <asm/unaligned.h>
#include <linux/crc8.h> #include <linux/crc8.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/i2c.h> #include <linux/i2c.h>
@ -19,27 +16,14 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/module.h> #include <linux/module.h>
#define SPS30_CRC8_POLYNOMIAL 0x31 #include "sps30.h"
/* max number of bytes needed to store PM measurements or serial string */
#define SPS30_MAX_READ_SIZE 48
/* sensor measures reliably up to 3000 ug / m3 */ /* sensor measures reliably up to 3000 ug / m3 */
#define SPS30_MAX_PM 3000 #define SPS30_MAX_PM 3000
/* minimum and maximum self cleaning periods in seconds */ /* minimum and maximum self cleaning periods in seconds */
#define SPS30_AUTO_CLEANING_PERIOD_MIN 0 #define SPS30_AUTO_CLEANING_PERIOD_MIN 0
#define SPS30_AUTO_CLEANING_PERIOD_MAX 604800 #define SPS30_AUTO_CLEANING_PERIOD_MAX 604800
/* SPS30 commands */
#define SPS30_START_MEAS 0x0010
#define SPS30_STOP_MEAS 0x0104
#define SPS30_RESET 0xd304
#define SPS30_READ_DATA_READY_FLAG 0x0202
#define SPS30_READ_DATA 0x0300
#define SPS30_READ_SERIAL 0xd033
#define SPS30_START_FAN_CLEANING 0x5607
#define SPS30_AUTO_CLEANING_PERIOD 0x8004
/* not a sensor command per se, used only to distinguish write from read */
#define SPS30_READ_AUTO_CLEANING_PERIOD 0x8005
enum { enum {
PM1, PM1,
PM2P5, PM2P5,
@ -52,114 +36,9 @@ enum {
MEASURING, MEASURING,
}; };
struct sps30_state { static s32 sps30_float_to_int_clamped(__be32 *fp)
struct i2c_client *client;
/*
* Guards against concurrent access to sensor registers.
* Must be held whenever sequence of commands is to be executed.
*/
struct mutex lock;
int state;
};
DECLARE_CRC8_TABLE(sps30_crc8_table);
static int sps30_write_then_read(struct sps30_state *state, u8 *txbuf,
int txsize, u8 *rxbuf, int rxsize)
{ {
int ret; int val = be32_to_cpup(fp);
/*
* Sensor does not support repeated start so instead of
* sending two i2c messages in a row we just send one by one.
*/
ret = i2c_master_send(state->client, txbuf, txsize);
if (ret != txsize)
return ret < 0 ? ret : -EIO;
if (!rxbuf)
return 0;
ret = i2c_master_recv(state->client, rxbuf, rxsize);
if (ret != rxsize)
return ret < 0 ? ret : -EIO;
return 0;
}
static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size)
{
/*
* Internally sensor stores measurements in a following manner:
*
* PM1: upper two bytes, crc8, lower two bytes, crc8
* PM2P5: upper two bytes, crc8, lower two bytes, crc8
* PM4: upper two bytes, crc8, lower two bytes, crc8
* PM10: upper two bytes, crc8, lower two bytes, crc8
*
* What follows next are number concentration measurements and
* typical particle size measurement which we omit.
*/
u8 buf[SPS30_MAX_READ_SIZE] = { cmd >> 8, cmd };
int i, ret = 0;
switch (cmd) {
case SPS30_START_MEAS:
buf[2] = 0x03;
buf[3] = 0x00;
buf[4] = crc8(sps30_crc8_table, &buf[2], 2, CRC8_INIT_VALUE);
ret = sps30_write_then_read(state, buf, 5, NULL, 0);
break;
case SPS30_STOP_MEAS:
case SPS30_RESET:
case SPS30_START_FAN_CLEANING:
ret = sps30_write_then_read(state, buf, 2, NULL, 0);
break;
case SPS30_READ_AUTO_CLEANING_PERIOD:
buf[0] = SPS30_AUTO_CLEANING_PERIOD >> 8;
buf[1] = (u8)(SPS30_AUTO_CLEANING_PERIOD & 0xff);
fallthrough;
case SPS30_READ_DATA_READY_FLAG:
case SPS30_READ_DATA:
case SPS30_READ_SERIAL:
/* every two data bytes are checksummed */
size += size / 2;
ret = sps30_write_then_read(state, buf, 2, buf, size);
break;
case SPS30_AUTO_CLEANING_PERIOD:
buf[2] = data[0];
buf[3] = data[1];
buf[4] = crc8(sps30_crc8_table, &buf[2], 2, CRC8_INIT_VALUE);
buf[5] = data[2];
buf[6] = data[3];
buf[7] = crc8(sps30_crc8_table, &buf[5], 2, CRC8_INIT_VALUE);
ret = sps30_write_then_read(state, buf, 8, NULL, 0);
break;
}
if (ret)
return ret;
/* validate received data and strip off crc bytes */
for (i = 0; i < size; i += 3) {
u8 crc = crc8(sps30_crc8_table, &buf[i], 2, CRC8_INIT_VALUE);
if (crc != buf[i + 2]) {
dev_err(&state->client->dev,
"data integrity check failed\n");
return -EIO;
}
*data++ = buf[i];
*data++ = buf[i + 1];
}
return 0;
}
static s32 sps30_float_to_int_clamped(const u8 *fp)
{
int val = get_unaligned_be32(fp);
int mantissa = val & GENMASK(22, 0); int mantissa = val & GENMASK(22, 0);
/* this is fine since passed float is always non-negative */ /* this is fine since passed float is always non-negative */
int exp = val >> 23; int exp = val >> 23;
@ -188,38 +67,35 @@ static s32 sps30_float_to_int_clamped(const u8 *fp)
static int sps30_do_meas(struct sps30_state *state, s32 *data, int size) static int sps30_do_meas(struct sps30_state *state, s32 *data, int size)
{ {
int i, ret, tries = 5; int i, ret;
u8 tmp[16];
if (state->state == RESET) { if (state->state == RESET) {
ret = sps30_do_cmd(state, SPS30_START_MEAS, NULL, 0); ret = state->ops->start_meas(state);
if (ret) if (ret)
return ret; return ret;
state->state = MEASURING; state->state = MEASURING;
} }
while (tries--) { ret = state->ops->read_meas(state, (__be32 *)data, size);
ret = sps30_do_cmd(state, SPS30_READ_DATA_READY_FLAG, tmp, 2);
if (ret)
return -EIO;
/* new measurements ready to be read */
if (tmp[1] == 1)
break;
msleep_interruptible(300);
}
if (tries == -1)
return -ETIMEDOUT;
ret = sps30_do_cmd(state, SPS30_READ_DATA, tmp, sizeof(int) * size);
if (ret) if (ret)
return ret; return ret;
for (i = 0; i < size; i++) for (i = 0; i < size; i++)
data[i] = sps30_float_to_int_clamped(&tmp[4 * i]); data[i] = sps30_float_to_int_clamped((__be32 *)&data[i]);
return 0;
}
static int sps30_do_reset(struct sps30_state *state)
{
int ret;
ret = state->ops->reset(state);
if (ret)
return ret;
state->state = RESET;
return 0; return 0;
} }
@ -310,24 +186,6 @@ static int sps30_read_raw(struct iio_dev *indio_dev,
return -EINVAL; return -EINVAL;
} }
static int sps30_do_cmd_reset(struct sps30_state *state)
{
int ret;
ret = sps30_do_cmd(state, SPS30_RESET, NULL, 0);
msleep(300);
/*
* Power-on-reset causes sensor to produce some glitch on i2c bus and
* some controllers end up in error state. Recover simply by placing
* some data on the bus, for example STOP_MEAS command, which
* is NOP in this case.
*/
sps30_do_cmd(state, SPS30_STOP_MEAS, NULL, 0);
state->state = RESET;
return ret;
}
static ssize_t start_cleaning_store(struct device *dev, static ssize_t start_cleaning_store(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
const char *buf, size_t len) const char *buf, size_t len)
@ -340,7 +198,7 @@ static ssize_t start_cleaning_store(struct device *dev,
return -EINVAL; return -EINVAL;
mutex_lock(&state->lock); mutex_lock(&state->lock);
ret = sps30_do_cmd(state, SPS30_START_FAN_CLEANING, NULL, 0); ret = state->ops->clean_fan(state);
mutex_unlock(&state->lock); mutex_unlock(&state->lock);
if (ret) if (ret)
return ret; return ret;
@ -349,31 +207,29 @@ static ssize_t start_cleaning_store(struct device *dev,
} }
static ssize_t cleaning_period_show(struct device *dev, static ssize_t cleaning_period_show(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct sps30_state *state = iio_priv(indio_dev); struct sps30_state *state = iio_priv(indio_dev);
u8 tmp[4]; __be32 val;
int ret; int ret;
mutex_lock(&state->lock); mutex_lock(&state->lock);
ret = sps30_do_cmd(state, SPS30_READ_AUTO_CLEANING_PERIOD, tmp, 4); ret = state->ops->read_cleaning_period(state, &val);
mutex_unlock(&state->lock); mutex_unlock(&state->lock);
if (ret) if (ret)
return ret; return ret;
return sprintf(buf, "%d\n", get_unaligned_be32(tmp)); return sprintf(buf, "%d\n", be32_to_cpu(val));
} }
static ssize_t cleaning_period_store(struct device *dev, static ssize_t cleaning_period_store(struct device *dev, struct device_attribute *attr,
struct device_attribute *attr, const char *buf, size_t len)
const char *buf, size_t len)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct sps30_state *state = iio_priv(indio_dev); struct sps30_state *state = iio_priv(indio_dev);
int val, ret; int val, ret;
u8 tmp[4];
if (kstrtoint(buf, 0, &val)) if (kstrtoint(buf, 0, &val))
return -EINVAL; return -EINVAL;
@ -382,10 +238,8 @@ static ssize_t cleaning_period_store(struct device *dev,
(val > SPS30_AUTO_CLEANING_PERIOD_MAX)) (val > SPS30_AUTO_CLEANING_PERIOD_MAX))
return -EINVAL; return -EINVAL;
put_unaligned_be32(val, tmp);
mutex_lock(&state->lock); mutex_lock(&state->lock);
ret = sps30_do_cmd(state, SPS30_AUTO_CLEANING_PERIOD, tmp, 0); ret = state->ops->write_cleaning_period(state, cpu_to_be32(val));
if (ret) { if (ret) {
mutex_unlock(&state->lock); mutex_unlock(&state->lock);
return ret; return ret;
@ -397,7 +251,7 @@ static ssize_t cleaning_period_store(struct device *dev,
* sensor requires reset in order to return up to date self cleaning * sensor requires reset in order to return up to date self cleaning
* period * period
*/ */
ret = sps30_do_cmd_reset(state); ret = sps30_do_reset(state);
if (ret) if (ret)
dev_warn(dev, dev_warn(dev,
"period changed but reads will return the old value\n"); "period changed but reads will return the old value\n");
@ -460,90 +314,65 @@ static const struct iio_chan_spec sps30_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(4), IIO_CHAN_SOFT_TIMESTAMP(4),
}; };
static void sps30_stop_meas(void *data) static void sps30_devm_stop_meas(void *data)
{ {
struct sps30_state *state = data; struct sps30_state *state = data;
sps30_do_cmd(state, SPS30_STOP_MEAS, NULL, 0); if (state->state == MEASURING)
state->ops->stop_meas(state);
} }
static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 }; static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 };
static int sps30_probe(struct i2c_client *client) int sps30_probe(struct device *dev, const char *name, void *priv, const struct sps30_ops *ops)
{ {
struct iio_dev *indio_dev; struct iio_dev *indio_dev;
struct sps30_state *state; struct sps30_state *state;
u8 buf[32];
int ret; int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
return -EOPNOTSUPP;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*state));
if (!indio_dev) if (!indio_dev)
return -ENOMEM; return -ENOMEM;
dev_set_drvdata(dev, indio_dev);
state = iio_priv(indio_dev); state = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev); state->dev = dev;
state->client = client; state->priv = priv;
state->state = RESET; state->ops = ops;
mutex_init(&state->lock);
indio_dev->info = &sps30_info; indio_dev->info = &sps30_info;
indio_dev->name = client->name; indio_dev->name = name;
indio_dev->channels = sps30_channels; indio_dev->channels = sps30_channels;
indio_dev->num_channels = ARRAY_SIZE(sps30_channels); indio_dev->num_channels = ARRAY_SIZE(sps30_channels);
indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->available_scan_masks = sps30_scan_masks; indio_dev->available_scan_masks = sps30_scan_masks;
mutex_init(&state->lock); ret = sps30_do_reset(state);
crc8_populate_msb(sps30_crc8_table, SPS30_CRC8_POLYNOMIAL);
ret = sps30_do_cmd_reset(state);
if (ret) { if (ret) {
dev_err(&client->dev, "failed to reset device\n"); dev_err(dev, "failed to reset device\n");
return ret; return ret;
} }
ret = sps30_do_cmd(state, SPS30_READ_SERIAL, buf, sizeof(buf)); ret = state->ops->show_info(state);
if (ret) { if (ret) {
dev_err(&client->dev, "failed to read serial number\n"); dev_err(dev, "failed to read device info\n");
return ret; return ret;
} }
/* returned serial number is already NUL terminated */
dev_info(&client->dev, "serial number: %s\n", buf);
ret = devm_add_action_or_reset(&client->dev, sps30_stop_meas, state); ret = devm_add_action_or_reset(dev, sps30_devm_stop_meas, state);
if (ret) if (ret)
return ret; return ret;
ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL, ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
sps30_trigger_handler, NULL); sps30_trigger_handler, NULL);
if (ret) if (ret)
return ret; return ret;
return devm_iio_device_register(&client->dev, indio_dev); return devm_iio_device_register(dev, indio_dev);
} }
EXPORT_SYMBOL_GPL(sps30_probe);
static const struct i2c_device_id sps30_id[] = {
{ "sps30" },
{ }
};
MODULE_DEVICE_TABLE(i2c, sps30_id);
static const struct of_device_id sps30_of_match[] = {
{ .compatible = "sensirion,sps30" },
{ }
};
MODULE_DEVICE_TABLE(of, sps30_of_match);
static struct i2c_driver sps30_driver = {
.driver = {
.name = "sps30",
.of_match_table = sps30_of_match,
},
.id_table = sps30_id,
.probe_new = sps30_probe,
};
module_i2c_driver(sps30_driver);
MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver"); MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");

35
drivers/iio/chemical/sps30.h Normal file
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@ -0,0 +1,35 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _SPS30_H
#define _SPS30_H
#include <linux/types.h>
struct sps30_state;
struct sps30_ops {
int (*start_meas)(struct sps30_state *state);
int (*stop_meas)(struct sps30_state *state);
int (*read_meas)(struct sps30_state *state, __be32 *meas, size_t num);
int (*reset)(struct sps30_state *state);
int (*clean_fan)(struct sps30_state *state);
int (*read_cleaning_period)(struct sps30_state *state, __be32 *period);
int (*write_cleaning_period)(struct sps30_state *state, __be32 period);
int (*show_info)(struct sps30_state *state);
};
struct sps30_state {
/* serialize access to the device */
struct mutex lock;
struct device *dev;
int state;
/*
* priv pointer is solely for serdev driver private data. We keep it
* here because driver_data inside dev has been already used for iio and
* struct serdev_device doesn't have one.
*/
void *priv;
const struct sps30_ops *ops;
};
int sps30_probe(struct device *dev, const char *name, void *priv, const struct sps30_ops *ops);
#endif

258
drivers/iio/chemical/sps30_i2c.c Normal file
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@ -0,0 +1,258 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Sensirion SPS30 particulate matter sensor i2c driver
*
* Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com>
*
* I2C slave address: 0x69
*/
#include <asm/unaligned.h>
#include <linux/crc8.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/types.h>
#include "sps30.h"
#define SPS30_I2C_CRC8_POLYNOMIAL 0x31
/* max number of bytes needed to store PM measurements or serial string */
#define SPS30_I2C_MAX_BUF_SIZE 48
DECLARE_CRC8_TABLE(sps30_i2c_crc8_table);
#define SPS30_I2C_START_MEAS 0x0010
#define SPS30_I2C_STOP_MEAS 0x0104
#define SPS30_I2C_READ_MEAS 0x0300
#define SPS30_I2C_MEAS_READY 0x0202
#define SPS30_I2C_RESET 0xd304
#define SPS30_I2C_CLEAN_FAN 0x5607
#define SPS30_I2C_PERIOD 0x8004
#define SPS30_I2C_READ_SERIAL 0xd033
#define SPS30_I2C_READ_VERSION 0xd100
static int sps30_i2c_xfer(struct sps30_state *state, unsigned char *txbuf, size_t txsize,
unsigned char *rxbuf, size_t rxsize)
{
struct i2c_client *client = to_i2c_client(state->dev);
int ret;
/*
* Sensor does not support repeated start so instead of
* sending two i2c messages in a row we just send one by one.
*/
ret = i2c_master_send(client, txbuf, txsize);
if (ret < 0)
return ret;
if (ret != txsize)
return -EIO;
if (!rxsize)
return 0;
ret = i2c_master_recv(client, rxbuf, rxsize);
if (ret < 0)
return ret;
if (ret != rxsize)
return -EIO;
return 0;
}
static int sps30_i2c_command(struct sps30_state *state, u16 cmd, void *arg, size_t arg_size,
void *rsp, size_t rsp_size)
{
/*
* Internally sensor stores measurements in a following manner:
*
* PM1: upper two bytes, crc8, lower two bytes, crc8
* PM2P5: upper two bytes, crc8, lower two bytes, crc8
* PM4: upper two bytes, crc8, lower two bytes, crc8
* PM10: upper two bytes, crc8, lower two bytes, crc8
*
* What follows next are number concentration measurements and
* typical particle size measurement which we omit.
*/
unsigned char buf[SPS30_I2C_MAX_BUF_SIZE];
unsigned char *tmp;
unsigned char crc;
size_t i;
int ret;
put_unaligned_be16(cmd, buf);
i = 2;
if (rsp) {
/* each two bytes are followed by a crc8 */
rsp_size += rsp_size / 2;
} else {
tmp = arg;
while (arg_size) {
buf[i] = *tmp++;
buf[i + 1] = *tmp++;
buf[i + 2] = crc8(sps30_i2c_crc8_table, buf + i, 2, CRC8_INIT_VALUE);
arg_size -= 2;
i += 3;
}
}
ret = sps30_i2c_xfer(state, buf, i, buf, rsp_size);
if (ret)
return ret;
/* validate received data and strip off crc bytes */
tmp = rsp;
for (i = 0; i < rsp_size; i += 3) {
crc = crc8(sps30_i2c_crc8_table, buf + i, 2, CRC8_INIT_VALUE);
if (crc != buf[i + 2]) {
dev_err(state->dev, "data integrity check failed\n");
return -EIO;
}
*tmp++ = buf[i];
*tmp++ = buf[i + 1];
}
return 0;
}
static int sps30_i2c_start_meas(struct sps30_state *state)
{
/* request BE IEEE754 formatted data */
unsigned char buf[] = { 0x03, 0x00 };
return sps30_i2c_command(state, SPS30_I2C_START_MEAS, buf, sizeof(buf), NULL, 0);
}
static int sps30_i2c_stop_meas(struct sps30_state *state)
{
return sps30_i2c_command(state, SPS30_I2C_STOP_MEAS, NULL, 0, NULL, 0);
}
static int sps30_i2c_reset(struct sps30_state *state)
{
int ret;
ret = sps30_i2c_command(state, SPS30_I2C_RESET, NULL, 0, NULL, 0);
msleep(500);
/*
* Power-on-reset causes sensor to produce some glitch on i2c bus and
* some controllers end up in error state. Recover simply by placing
* some data on the bus, for example STOP_MEAS command, which
* is NOP in this case.
*/
sps30_i2c_stop_meas(state);
return ret;
}
static bool sps30_i2c_meas_ready(struct sps30_state *state)
{
unsigned char buf[2];
int ret;
ret = sps30_i2c_command(state, SPS30_I2C_MEAS_READY, NULL, 0, buf, sizeof(buf));
if (ret)
return false;
return buf[1];
}
static int sps30_i2c_read_meas(struct sps30_state *state, __be32 *meas, size_t num)
{
/* measurements are ready within a second */
if (msleep_interruptible(1000))
return -EINTR;
if (!sps30_i2c_meas_ready(state))
return -ETIMEDOUT;
return sps30_i2c_command(state, SPS30_I2C_READ_MEAS, NULL, 0, meas, sizeof(num) * num);
}
static int sps30_i2c_clean_fan(struct sps30_state *state)
{
return sps30_i2c_command(state, SPS30_I2C_CLEAN_FAN, NULL, 0, NULL, 0);
}
static int sps30_i2c_read_cleaning_period(struct sps30_state *state, __be32 *period)
{
return sps30_i2c_command(state, SPS30_I2C_PERIOD, NULL, 0, period, sizeof(*period));
}
static int sps30_i2c_write_cleaning_period(struct sps30_state *state, __be32 period)
{
return sps30_i2c_command(state, SPS30_I2C_PERIOD, &period, sizeof(period), NULL, 0);
}
static int sps30_i2c_show_info(struct sps30_state *state)
{
/* extra nul just in case */
unsigned char buf[32 + 1] = { 0x00 };
int ret;
ret = sps30_i2c_command(state, SPS30_I2C_READ_SERIAL, NULL, 0, buf, sizeof(buf) - 1);
if (ret)
return ret;
dev_info(state->dev, "serial number: %s\n", buf);
ret = sps30_i2c_command(state, SPS30_I2C_READ_VERSION, NULL, 0, buf, 2);
if (ret)
return ret;
dev_info(state->dev, "fw version: %u.%u\n", buf[0], buf[1]);
return 0;
}
static const struct sps30_ops sps30_i2c_ops = {
.start_meas = sps30_i2c_start_meas,
.stop_meas = sps30_i2c_stop_meas,
.read_meas = sps30_i2c_read_meas,
.reset = sps30_i2c_reset,
.clean_fan = sps30_i2c_clean_fan,
.read_cleaning_period = sps30_i2c_read_cleaning_period,
.write_cleaning_period = sps30_i2c_write_cleaning_period,
.show_info = sps30_i2c_show_info,
};
static int sps30_i2c_probe(struct i2c_client *client)
{
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -EOPNOTSUPP;
crc8_populate_msb(sps30_i2c_crc8_table, SPS30_I2C_CRC8_POLYNOMIAL);
return sps30_probe(&client->dev, client->name, NULL, &sps30_i2c_ops);
}
static const struct i2c_device_id sps30_i2c_id[] = {
{ "sps30" },
{ }
};
MODULE_DEVICE_TABLE(i2c, sps30_i2c_id);
static const struct of_device_id sps30_i2c_of_match[] = {
{ .compatible = "sensirion,sps30" },
{ }
};
MODULE_DEVICE_TABLE(of, sps30_i2c_of_match);
static struct i2c_driver sps30_i2c_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = sps30_i2c_of_match,
},
.id_table = sps30_i2c_id,
.probe_new = sps30_i2c_probe,
};
module_i2c_driver(sps30_i2c_driver);
MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>");
MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor i2c driver");
MODULE_LICENSE("GPL v2");