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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B3A5BC433ED for ; Mon, 26 Apr 2021 10:25:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70B4061185 for ; Mon, 26 Apr 2021 10:25:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232266AbhDZKZw (ORCPT ); Mon, 26 Apr 2021 06:25:52 -0400 Received: from smtpout1.mo528.mail-out.ovh.net ([46.105.34.251]:59727 "EHLO smtpout1.mo528.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232194AbhDZKZw (ORCPT ); Mon, 26 Apr 2021 06:25:52 -0400 Received: from pro2.mail.ovh.net (unknown [10.108.16.80]) by mo528.mail-out.ovh.net (Postfix) with ESMTPS id 68C3CA260B53; Mon, 26 Apr 2021 12:25:05 +0200 (CEST) Received: from localhost (89.70.221.198) by DAG2EX1.emp2.local (172.16.2.11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Mon, 26 Apr 2021 12:25:04 +0200 Date: Mon, 26 Apr 2021 12:20:59 +0200 From: Tomasz Duszynski To: Jonathan Cameron CC: Tomasz Duszynski , , , , , Subject: Re: [PATCH 1/3] iio: sps30: separate core and interface specific code Message-ID: References: <20210425135546.57343-1-tomasz.duszynski@octakon.com> <20210425135546.57343-2-tomasz.duszynski@octakon.com> <20210425164613.7eda8f6c@jic23-huawei> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20210425164613.7eda8f6c@jic23-huawei> X-Originating-IP: [89.70.221.198] X-ClientProxiedBy: DAG3EX1.emp2.local (172.16.2.21) To DAG2EX1.emp2.local (172.16.2.11) X-Ovh-Tracer-Id: 10736862988391308370 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: 0 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrvddukedgvdelucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucenucfjughrpeffhffvuffkfhggtggujghisehttdortddttdejnecuhfhrohhmpefvohhmrghsiicuffhushiihihnshhkihcuoehtohhmrghsiidrughushiihihnshhkihesohgtthgrkhhonhdrtghomheqnecuggftrfgrthhtvghrnhepkeejgfevledtgfdtfeettdektedvieeiveduueetudekieetiedujedtleevleelnecukfhppedtrddtrddtrddtpdekledrjedtrddvvddurdduleeknecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepphhrohdvrdhmrghilhdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomhepthhomhgrshiirdguuhhsiiihnhhskhhisehotghtrghkohhnrdgtohhmpdhrtghpthhtoheprhhosghhodgutheskhgvrhhnvghlrdhorhhg Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sun, Apr 25, 2021 at 04:46:13PM +0100, Jonathan Cameron wrote: > On Sun, 25 Apr 2021 15:55:44 +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 > > Hi Tomasz, > > This seems rather less minimal than I'd usually expect for this sort of refactor > but (other than a few things commented on inline) it seems like all the other > bits of refactoring are sensible to me. Good. I though about splitting the work into more patches but eventually I realized it's going to create more noise than really necessary. > > Thanks, > > Jonathan > > > --- > > MAINTAINERS | 1 + > > drivers/iio/chemical/Kconfig | 13 +- > > drivers/iio/chemical/Makefile | 1 + > > drivers/iio/chemical/sps30.c | 270 ++++++------------------------- > > drivers/iio/chemical/sps30.h | 73 +++++++++ > > drivers/iio/chemical/sps30_i2c.c | 256 +++++++++++++++++++++++++++++ > > 6 files changed, 391 insertions(+), 223 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..82af5f62fbc6 100644 > > --- a/drivers/iio/chemical/Kconfig > > +++ b/drivers/iio/chemical/Kconfig > > @@ -133,8 +133,6 @@ config SENSIRION_SGP30 > > > > config SPS30 > > tristate "SPS30 particulate matter sensor" > > One option here is to simplify the Kconfig memu options by > dropping the text above so the option is hidden then selecting > this option (rather than depends) for the bus specific drivers. > Ack. > > - depends on I2C > > - select CRC8 > > select IIO_BUFFER > > select IIO_TRIGGERED_BUFFER > > help > > @@ -144,6 +142,17 @@ config SPS30 > > To compile this driver as a module, choose M here: the module will > > be called sps30. > > > > +config SPS30_I2C > > + tristate "SPS30 particulate matter sensor I2C driver" > > + depends on SPS30 && I2C > > + select CRC8 > > + help > > + 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_i2c. > > + > > config VZ89X > > tristate "SGX Sensortech MiCS VZ89X VOC sensor" > > depends on I2C > > 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..ec9db99e324c 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_cpu(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 = sps30_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 = sps30_read_meas(state, 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((__force __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 = sps30_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 = sps30_clean_fan(state); > > mutex_unlock(&state->lock); > > if (ret) > > return ret; > > @@ -349,31 +207,28 @@ 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]; > > - int ret; > > + int val, ret; > > > > mutex_lock(&state->lock); > > - ret = sps30_do_cmd(state, SPS30_READ_AUTO_CLEANING_PERIOD, tmp, 4); > > + ret = sps30_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((__force __be32)val)); > > As below, I'm not seeing the necessity of this cast. Just make val a > __be32 and deal with parameters being passed around as that type. > Sure. > > } > > > > -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 +237,8 @@ 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 = sps30_write_cleaning_period(state, (__force int)cpu_to_be32(val)); > > I guess this is related to the below question of the type of period parameter. > I'd make it a be32 directly if that's what it actually is! > Sure. > > if (ret) { > > mutex_unlock(&state->lock); > > return ret; > > @@ -397,7 +250,7 @@ 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 +313,65 @@ 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) > > + sps30_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 = sps30_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(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..d2b7140fdeb4 > > --- /dev/null > > +++ b/drivers/iio/chemical/sps30.h > > @@ -0,0 +1,73 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > +#ifndef _SPS30_H > > +#define _SPS30_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, int *meas, int num); > > + int (*reset)(struct sps30_state *state); > > + int (*clean_fan)(struct sps30_state *state); > > + int (*read_cleaning_period)(struct sps30_state *state, int *period); > > As mentioned below, I think period should be a fixed width type. > > > + int (*write_cleaning_period)(struct sps30_state *state, int 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); > > + > > +static inline int sps30_start_meas(struct sps30_state *state) > > +{ > > + return state->ops->start_meas(state); > > I'm not convinced the following wrappers are worthwhile. > Most of these are only called in one or two places and having the > ops structure exposed in the calls doesn't really matter much for readability etc. > No strong opinions here. Will drop them altogether in v2. > > +} > > + > > +static inline int sps30_stop_meas(struct sps30_state *state) > > +{ > > + return state->ops->stop_meas(state); > > +} > > + > > +static inline int sps30_read_meas(struct sps30_state *state, void *meas, int num) > > +{ > > + return state->ops->read_meas(state, meas, num); > > +} > > + > > +static inline int sps30_clean_fan(struct sps30_state *state) > > +{ > > + return state->ops->clean_fan(state); > > +} > > + > > +static inline int sps30_write_cleaning_period(struct sps30_state *state, int period) > > +{ > > + return state->ops->write_cleaning_period(state, period); > > +} > > + > > +static inline int sps30_read_cleaning_period(struct sps30_state *state, int *period) > > +{ > > + return state->ops->read_cleaning_period(state, period); > > +} > > + > > +static inline int sps30_show_info(struct sps30_state *state) > > +{ > > + return state->ops->show_info(state); > > +} > > + > > +static inline int sps30_reset(struct sps30_state *state) > > +{ > > + return state->ops->reset(state); > > +} > > + > > +#endif > > diff --git a/drivers/iio/chemical/sps30_i2c.c b/drivers/iio/chemical/sps30_i2c.c > > new file mode 100644 > > index 000000000000..97146cd50aa5 > > --- /dev/null > > +++ b/drivers/iio/chemical/sps30_i2c.c > > @@ -0,0 +1,256 @@ > > +// 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, char *txbuf, int txsize, > > + char *rxbuf, int 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, int arg_size, > > + void *rsp, int 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. > > + */ > > + char buf[SPS30_I2C_MAX_BUF_SIZE]; > > + int i, ret; > > + char *tmp; > > + char crc; > > + > > + 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 */ > > + 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) > > +{ > > + 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, int *meas, int num) > > +{ > > + int tries = 3; > > + > > + do { > > + if (sps30_i2c_meas_ready(state)) > > + break; > > + > > + if (msleep_interruptible(500)) > > + return -EINTR; > > + } while (--tries); > > + > > + if (!tries) > > + 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, int *period) > > +{ > > + return sps30_i2c_command(state, SPS30_I2C_PERIOD, NULL, 0, period, sizeof(*period)); > > Do you not want a fixed size type of period? u32 or something like that? > > > +} > > + > > +static int sps30_i2c_write_cleaning_period(struct sps30_state *state, int 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 */ > > + 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" }, > > + { } > > +}; > > +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"); >