From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68685C433B4 for ; Sun, 2 May 2021 17:31:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34D3E610C9 for ; Sun, 2 May 2021 17:31:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231801AbhEBRcX (ORCPT ); Sun, 2 May 2021 13:32:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:48144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230110AbhEBRcW (ORCPT ); Sun, 2 May 2021 13:32:22 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 74B6561186; Sun, 2 May 2021 17:31:29 +0000 (UTC) Date: Sun, 2 May 2021 18:32:20 +0100 From: Jonathan Cameron To: Tomasz Duszynski Cc: , , , , Subject: Re: [PATCH v2 1/3] iio: sps30: separate core and interface specific code Message-ID: <20210502183220.0ed8ff1c@jic23-huawei> In-Reply-To: <20210502134431.42647-2-tomasz.duszynski@octakon.com> References: <20210502134431.42647-1-tomasz.duszynski@octakon.com> <20210502134431.42647-2-tomasz.duszynski@octakon.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sun, 2 May 2021 15:44:29 +0200 Tomasz Duszynski 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 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 > 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 > 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 > - * > - * I2C slave address: 0x69 > */ > > -#include > #include > #include > #include > @@ -19,27 +16,14 @@ > #include > #include > > -#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 "); > 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 > + > +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 > + * > + * I2C slave address: 0x69 > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#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 "); > +MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor i2c driver"); > +MODULE_LICENSE("GPL v2");