From patchwork Sun May 2 13:44:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomasz Duszynski X-Patchwork-Id: 12235195 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D2C98C43460 for ; Sun, 2 May 2021 13:48:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B109D613AF for ; Sun, 2 May 2021 13:48:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232167AbhEBNtp (ORCPT ); Sun, 2 May 2021 09:49:45 -0400 Received: from smtpout1.mo3004.mail-out.ovh.net ([79.137.123.219]:34841 "EHLO smtpout1.mo3004.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232047AbhEBNtp (ORCPT ); Sun, 2 May 2021 09:49:45 -0400 Received: from pro2.mail.ovh.net (unknown [10.109.156.240]) by mo3004.mail-out.ovh.net (Postfix) with ESMTPS id 714C223CF5A; Sun, 2 May 2021 13:48:52 +0000 (UTC) Received: from arch.lan (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; Sun, 2 May 2021 15:48:51 +0200 From: Tomasz Duszynski To: CC: , , , , , Tomasz Duszynski Subject: [PATCH v2 1/3] iio: sps30: separate core and interface specific code Date: Sun, 2 May 2021 15:44:29 +0200 Message-ID: <20210502134431.42647-2-tomasz.duszynski@octakon.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210502134431.42647-1-tomasz.duszynski@octakon.com> References: <20210502134431.42647-1-tomasz.duszynski@octakon.com> MIME-Version: 1.0 X-Originating-IP: [89.70.221.198] X-ClientProxiedBy: DAG4EX1.emp2.local (172.16.2.31) To DAG2EX1.emp2.local (172.16.2.11) X-Ovh-Tracer-Id: 12521132865423301655 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: 0 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrvdefuddguddvtdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecunecujfgurhephffvufffkffojghfggfgtghisehtkeertdertddtnecuhfhrohhmpefvohhmrghsiicuffhushiihihnshhkihcuoehtohhmrghsiidrughushiihihnshhkihesohgtthgrkhhonhdrtghomheqnecuggftrfgrthhtvghrnhepveejvdekueeiheevgeegudduvdfhudfhhfehudefjeduheekuefhgfehudffuddunecukfhppedtrddtrddtrddtpdekledrjedtrddvvddurdduleeknecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepphhrohdvrdhmrghilhdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomhepthhomhgrshiirdguuhhsiiihnhhskhhisehotghtrghkohhnrdgtohhmpdhrtghpthhtoheprhhosghhodgutheskhgvrhhnvghlrdhorhhg Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 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 --- 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" }, + { } +}; +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");