On Sun, 2 May 2021 15:44:29 +0200
Tomasz Duszynski <tomasz.duszynski@xxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxx>
A comment way down the end. Basically says that dropping the i2c_device_id
table is fine with me, but does occasionally cause problems as it's still used
IIRC by greybus. Maybe someone will one day connect one of these to greybus :)
Otherwise, looks good to me.
Jonathan
> ---
> MAINTAINERS | 1 +
> drivers/iio/chemical/Kconfig | 16 +-
> drivers/iio/chemical/Makefile | 1 +
> drivers/iio/chemical/sps30.c | 269 ++++++-------------------------
> drivers/iio/chemical/sps30.h | 35 ++++
> drivers/iio/chemical/sps30_i2c.c | 251 ++++++++++++++++++++++++++++
> 6 files changed, 347 insertions(+), 226 deletions(-)
> create mode 100644 drivers/iio/chemical/sps30.h
> create mode 100644 drivers/iio/chemical/sps30_i2c.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ccc59fd7e5c0..4b39a9c48736 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16137,6 +16137,7 @@ M: Tomasz Duszynski <tduszyns@xxxxxxxxx>
> S: Maintained
> F: Documentation/devicetree/bindings/iio/chemical/sensirion,sps30.yaml
> F: drivers/iio/chemical/sps30.c
> +F: drivers/iio/chemical/sps30_i2c.c
>
> SERIAL DEVICE BUS
> M: Rob Herring <robh@xxxxxxxxxx>
> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> index 10bb431bc3ce..2b45a76ab7bc 100644
> --- a/drivers/iio/chemical/Kconfig
> +++ b/drivers/iio/chemical/Kconfig
> @@ -132,17 +132,21 @@ config SENSIRION_SGP30
> module will be called sgp30.
>
> config SPS30
> - tristate "SPS30 particulate matter sensor"
> - depends on I2C
> - select CRC8
> + tristate
> select IIO_BUFFER
> select IIO_TRIGGERED_BUFFER
> +
> +config SPS30_I2C
> + tristate "SPS30 particulate matter sensor I2C driver"
> + depends on I2C
> + select SPS30
> + select CRC8
> help
> - Say Y here to build support for the Sensirion SPS30 particulate
> - matter sensor.
> + Say Y here to build support for the Sensirion SPS30 I2C interface
> + driver.
>
> To compile this driver as a module, choose M here: the module will
> - be called sps30.
> + be called sps30_i2c.
>
> config VZ89X
> tristate "SGX Sensortech MiCS VZ89X VOC sensor"
> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> index fef63dd5bf92..41c264a229c0 100644
> --- a/drivers/iio/chemical/Makefile
> +++ b/drivers/iio/chemical/Makefile
> @@ -17,4 +17,5 @@ obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o
> obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o
> obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o
> obj-$(CONFIG_SPS30) += sps30.o
> +obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
> obj-$(CONFIG_VZ89X) += vz89x.o
> diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
> index 7486591588c3..d51314505115 100644
> --- a/drivers/iio/chemical/sps30.c
> +++ b/drivers/iio/chemical/sps30.c
> @@ -3,11 +3,8 @@
> * Sensirion SPS30 particulate matter sensor driver
> *
> * Copyright (c) Tomasz Duszynski <tduszyns@xxxxxxxxx>
> - *
> - * I2C slave address: 0x69
> */
>
> -#include <asm/unaligned.h>
> #include <linux/crc8.h>
> #include <linux/delay.h>
> #include <linux/i2c.h>
> @@ -19,27 +16,14 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
>
> -#define SPS30_CRC8_POLYNOMIAL 0x31
> -/* max number of bytes needed to store PM measurements or serial string */
> -#define SPS30_MAX_READ_SIZE 48
> +#include "sps30.h"
> +
> /* sensor measures reliably up to 3000 ug / m3 */
> #define SPS30_MAX_PM 3000
> /* minimum and maximum self cleaning periods in seconds */
> #define SPS30_AUTO_CLEANING_PERIOD_MIN 0
> #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 {
> PM1,
> PM2P5,
> @@ -52,114 +36,9 @@ enum {
> MEASURING,
> };
>
> -struct sps30_state {
> - 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;
> -
> - /*
> - * 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)
> +static s32 sps30_float_to_int_clamped(__be32 *fp)
> {
> - int val = get_unaligned_be32(fp);
> + int val = be32_to_cpup(fp);
> int mantissa = val & GENMASK(22, 0);
> /* this is fine since passed float is always non-negative */
> 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)
> {
> - int i, ret, tries = 5;
> - u8 tmp[16];
> + int i, ret;
>
> if (state->state == RESET) {
> - ret = sps30_do_cmd(state, SPS30_START_MEAS, NULL, 0);
> + ret = state->ops->start_meas(state);
> if (ret)
> return ret;
>
> state->state = MEASURING;
> }
>
> - while (tries--) {
> - ret = sps30_do_cmd(state, SPS30_READ_DATA_READY_FLAG, tmp, 2);
> - if (ret)
> - return -EIO;
> + ret = state->ops->read_meas(state, (__be32 *)data, size);
> + if (ret)
> + return ret;
>
> - /* new measurements ready to be read */
> - if (tmp[1] == 1)
> - break;
> + for (i = 0; i < size; i++)
> + data[i] = sps30_float_to_int_clamped((__be32 *)&data[i]);
>
> - msleep_interruptible(300);
> - }
> + return 0;
> +}
>
> - if (tries == -1)
> - return -ETIMEDOUT;
> +static int sps30_do_reset(struct sps30_state *state)
> +{
> + int ret;
>
> - ret = sps30_do_cmd(state, SPS30_READ_DATA, tmp, sizeof(int) * size);
> + ret = state->ops->reset(state);
> if (ret)
> return ret;
>
> - for (i = 0; i < size; i++)
> - data[i] = sps30_float_to_int_clamped(&tmp[4 * i]);
> + state->state = RESET;
>
> return 0;
> }
> @@ -310,24 +186,6 @@ static int sps30_read_raw(struct iio_dev *indio_dev,
> 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,
> struct device_attribute *attr,
> const char *buf, size_t len)
> @@ -340,7 +198,7 @@ static ssize_t start_cleaning_store(struct device *dev,
> return -EINVAL;
>
> 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);
> if (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,
> - struct device_attribute *attr,
> - char *buf)
> + struct device_attribute *attr,
> + char *buf)
> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> struct sps30_state *state = iio_priv(indio_dev);
> - u8 tmp[4];
> + __be32 val;
> int ret;
>
> 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);
> if (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,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> +static ssize_t cleaning_period_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t len)
> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> struct sps30_state *state = iio_priv(indio_dev);
> int val, ret;
> - u8 tmp[4];
>
> if (kstrtoint(buf, 0, &val))
> return -EINVAL;
> @@ -382,10 +238,8 @@ static ssize_t cleaning_period_store(struct device *dev,
> (val > SPS30_AUTO_CLEANING_PERIOD_MAX))
> return -EINVAL;
>
> - put_unaligned_be32(val, tmp);
> -
> 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) {
> mutex_unlock(&state->lock);
> 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
> * period
> */
> - ret = sps30_do_cmd_reset(state);
> + ret = sps30_do_reset(state);
> if (ret)
> dev_warn(dev,
> "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),
> };
>
> -static void sps30_stop_meas(void *data)
> +static void sps30_devm_stop_meas(void *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 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 sps30_state *state;
> - u8 buf[32];
> int ret;
>
> - if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
> - return -EOPNOTSUPP;
> -
> - indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*state));
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
> if (!indio_dev)
> return -ENOMEM;
>
> + dev_set_drvdata(dev, indio_dev);
> +
> state = iio_priv(indio_dev);
> - i2c_set_clientdata(client, indio_dev);
> - state->client = client;
> - state->state = RESET;
> + state->dev = dev;
> + state->priv = priv;
> + state->ops = ops;
> + mutex_init(&state->lock);
> +
> indio_dev->info = &sps30_info;
> - indio_dev->name = client->name;
> + indio_dev->name = name;
> indio_dev->channels = sps30_channels;
> indio_dev->num_channels = ARRAY_SIZE(sps30_channels);
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->available_scan_masks = sps30_scan_masks;
>
> - mutex_init(&state->lock);
> - crc8_populate_msb(sps30_crc8_table, SPS30_CRC8_POLYNOMIAL);
> -
> - ret = sps30_do_cmd_reset(state);
> + ret = sps30_do_reset(state);
> if (ret) {
> - dev_err(&client->dev, "failed to reset device\n");
> + dev_err(dev, "failed to reset device\n");
> return ret;
> }
>
> - ret = sps30_do_cmd(state, SPS30_READ_SERIAL, buf, sizeof(buf));
> + ret = state->ops->show_info(state);
> if (ret) {
> - dev_err(&client->dev, "failed to read serial number\n");
> + dev_err(dev, "failed to read device info\n");
> 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)
> 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);
> if (ret)
> return ret;
>
> - return devm_iio_device_register(&client->dev, indio_dev);
> + return devm_iio_device_register(dev, indio_dev);
> }
> -
> -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);
> +EXPORT_SYMBOL_GPL(sps30_probe);
>
> MODULE_AUTHOR("Tomasz Duszynski <tduszyns@xxxxxxxxx>");
> MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
> diff --git a/drivers/iio/chemical/sps30.h b/drivers/iio/chemical/sps30.h
> new file mode 100644
> index 000000000000..a58ee43cf45d
> --- /dev/null
> +++ b/drivers/iio/chemical/sps30.h
> @@ -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
> diff --git a/drivers/iio/chemical/sps30_i2c.c b/drivers/iio/chemical/sps30_i2c.c
> new file mode 100644
> index 000000000000..123ef23bf0eb
> --- /dev/null
> +++ b/drivers/iio/chemical/sps30_i2c.c
> @@ -0,0 +1,251 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Sensirion SPS30 particulate matter sensor i2c driver
> + *
> + * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@xxxxxxxxxxx>
> + *
> + * 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 of_device_id sps30_i2c_of_match[] = {
> + { .compatible = "sensirion,sps30" },
This drops the i2c_device_id table. I personally don't mind doing that, but
it will cause trouble for anyone trying to use greybus or similar with this part
(as IIRC they still rely on that id table).
> + { }
> +};
> +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,
> + },
> + .probe_new = sps30_i2c_probe,
> +};
> +module_i2c_driver(sps30_i2c_driver);
> +
> +MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor i2c driver");
> +MODULE_LICENSE("GPL v2");
