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[23.128.96.18]) by mx.google.com with ESMTP id a7si8048423ejx.527.2021.05.02.10.38.35; Sun, 02 May 2021 10:38:59 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231958AbhEBRiY (ORCPT + 99 others); Sun, 2 May 2021 13:38:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:52990 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230110AbhEBRiY (ORCPT ); Sun, 2 May 2021 13:38:24 -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 28B6861264; Sun, 2 May 2021 17:37:30 +0000 (UTC) Date: Sun, 2 May 2021 18:38:22 +0100 From: Jonathan Cameron To: Tomasz Duszynski Cc: , , , , Subject: Re: [PATCH v2 2/3] iio: sps30: add support for serial interface Message-ID: <20210502183822.1dec23cc@jic23-huawei> In-Reply-To: <20210502134431.42647-3-tomasz.duszynski@octakon.com> References: <20210502134431.42647-1-tomasz.duszynski@octakon.com> <20210502134431.42647-3-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-kernel@vger.kernel.org On Sun, 2 May 2021 15:44:30 +0200 Tomasz Duszynski wrote: > Sensor has support for both i2c and serial communication interfaces. > Both offer very similar set of features. Minor differences don't impact > overall functionality like doing measurements, etc. > > Support for i2c have already been added, this patch adds support > for the latter ie. serial interface. > > Signed-off-by: Tomasz Duszynski Two trivial comments inline. I'm happy to tidy those up whilst applying if everyone else is happy with this and you don't need to do a v3. Thanks, Jonathan > --- > MAINTAINERS | 1 + > drivers/iio/chemical/Kconfig | 11 + > drivers/iio/chemical/Makefile | 1 + > drivers/iio/chemical/sps30_serial.c | 428 ++++++++++++++++++++++++++++ > 4 files changed, 441 insertions(+) > create mode 100644 drivers/iio/chemical/sps30_serial.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 4b39a9c48736..cab9a63ad2cf 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -16138,6 +16138,7 @@ S: Maintained > F: Documentation/devicetree/bindings/iio/chemical/sensirion,sps30.yaml > F: drivers/iio/chemical/sps30.c > F: drivers/iio/chemical/sps30_i2c.c > +F: drivers/iio/chemical/sps30_serial.c > > SERIAL DEVICE BUS > M: Rob Herring > diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig > index 2b45a76ab7bc..a4920646e9be 100644 > --- a/drivers/iio/chemical/Kconfig > +++ b/drivers/iio/chemical/Kconfig > @@ -148,6 +148,17 @@ config SPS30_I2C > To compile this driver as a module, choose M here: the module will > be called sps30_i2c. > > +config SPS30_SERIAL > + tristate "SPS30 particulate matter sensor serial driver" > + depends on SERIAL_DEV_BUS > + select SPS30 > + help > + Say Y here to build support for the Sensirion SPS30 serial interface > + driver. > + > + To compile this driver as a module, choose M here: the module will > + be called sps30_serial. > + > 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 41c264a229c0..4898690cc155 100644 > --- a/drivers/iio/chemical/Makefile > +++ b/drivers/iio/chemical/Makefile > @@ -18,4 +18,5 @@ 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-$(CONFIG_SPS30_SERIAL) += sps30_serial.o > obj-$(CONFIG_VZ89X) += vz89x.o > diff --git a/drivers/iio/chemical/sps30_serial.c b/drivers/iio/chemical/sps30_serial.c > new file mode 100644 > index 000000000000..3dc1a9e2ae82 > --- /dev/null > +++ b/drivers/iio/chemical/sps30_serial.c > @@ -0,0 +1,428 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Sensirion SPS30 particulate matter sensor serial driver > + * > + * Copyright (c) 2021 Tomasz Duszynski > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "sps30.h" > + > +#define SPS30_SERIAL_DEV_NAME "sps30" > + > +#define SPS30_SERIAL_SOF_EOF 0x7e > +#define SPS30_SERIAL_TIMEOUT msecs_to_jiffies(20) > +#define SPS30_SERIAL_MAX_BUF_SIZE 263 > +#define SPS30_SERIAL_ESCAPE_CHAR 0x7d > + > +#define SPS30_SERIAL_FRAME_MIN_SIZE 7 > +#define SPS30_SERIAL_FRAME_ADR_OFFSET 1 > +#define SPS30_SERIAL_FRAME_CMD_OFFSET 2 > +#define SPS30_SERIAL_FRAME_MOSI_LEN_OFFSET 3 > +#define SPS30_SERIAL_FRAME_MISO_STATE_OFFSET 3 > +#define SPS30_SERIAL_FRAME_MISO_LEN_OFFSET 4 > +#define SPS30_SERIAL_FRAME_MISO_DATA_OFFSET 5 > + > +#define SPS30_SERIAL_START_MEAS 0x00 > +#define SPS30_SERIAL_STOP_MEAS 0x01 > +#define SPS30_SERIAL_READ_MEAS 0x03 > +#define SPS30_SERIAL_RESET 0xd3 > +#define SPS30_SERIAL_CLEAN_FAN 0x56 > +#define SPS30_SERIAL_PERIOD 0x80 > +#define SPS30_SERIAL_DEV_INFO 0xd0 > +#define SPS30_SERIAL_READ_VERSION 0xd1 > + > +struct sps30_serial_priv { > + struct completion new_frame; > + unsigned char buf[SPS30_SERIAL_MAX_BUF_SIZE]; > + size_t num; > + bool escaped; > + bool done; > +}; > + > +static int sps30_serial_xfer(struct sps30_state *state, const unsigned char *buf, size_t size) > +{ > + struct serdev_device *serdev = to_serdev_device(state->dev); > + struct sps30_serial_priv *priv = state->priv; > + int ret; > + > + priv->num = 0; > + priv->escaped = false; > + priv->done = false; > + > + ret = serdev_device_write(serdev, buf, size, SPS30_SERIAL_TIMEOUT); > + if (ret < 0) > + return ret; > + if (ret != size) > + return -EIO; > + > + ret = wait_for_completion_interruptible_timeout(&priv->new_frame, SPS30_SERIAL_TIMEOUT); > + if (ret < 0) > + return ret; > + if (!ret) > + return -ETIMEDOUT; > + > + return 0; > +} > + > +static struct { > + unsigned char byte; > + unsigned char byte2; > +} sps30_serial_bytes[] = { > + { 0x11, 0x31 }, > + { 0x13, 0x33 }, > + { 0x7e, 0x5e }, > + { 0x7d, 0x5d }, > +}; const? > + > +static int sps30_serial_put_byte(unsigned char *buf, unsigned char byte) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(sps30_serial_bytes); i++) { > + if (sps30_serial_bytes[i].byte != byte) > + continue; > + > + buf[0] = SPS30_SERIAL_ESCAPE_CHAR; > + buf[1] = sps30_serial_bytes[i].byte2; > + > + return 2; > + } > + > + buf[0] = byte; > + > + return 1; > +} > + > +static char sps30_serial_get_byte(bool escaped, unsigned char byte2) > +{ > + int i; > + > + if (!escaped) > + return byte2; > + > + for (i = 0; i < ARRAY_SIZE(sps30_serial_bytes); i++) { > + if (sps30_serial_bytes[i].byte2 != byte2) > + continue; > + > + return sps30_serial_bytes[i].byte; > + } > + > + return 0; > +} > + > +static unsigned char sps30_serial_calc_chksum(const unsigned char *buf, size_t num) > +{ > + unsigned int chksum = 0; > + size_t i; > + > + for (i = 0; i < num; i++) > + chksum += buf[i]; > + > + return ~chksum; > +} > + > +static int sps30_serial_prep_frame(unsigned char *buf, unsigned char cmd, > + const unsigned char *arg, size_t arg_size) > +{ > + unsigned char chksum; > + int num = 0; > + size_t i; > + > + buf[num++] = SPS30_SERIAL_SOF_EOF; > + buf[num++] = 0; > + num += sps30_serial_put_byte(buf + num, cmd); > + num += sps30_serial_put_byte(buf + num, arg_size); > + > + for (i = 0; i < arg_size; i++) > + num += sps30_serial_put_byte(buf + num, arg[i]); > + > + /* SOF isn't checksummed */ > + chksum = sps30_serial_calc_chksum(buf + 1, num - 1); > + num += sps30_serial_put_byte(buf + num, chksum); > + buf[num++] = SPS30_SERIAL_SOF_EOF; > + > + return num; > +} > + > +static bool sps30_serial_frame_valid(struct sps30_state *state, const unsigned char *buf) > +{ > + struct sps30_serial_priv *priv = state->priv; > + unsigned char chksum; > + > + if ((priv->num < SPS30_SERIAL_FRAME_MIN_SIZE) || > + (priv->num != SPS30_SERIAL_FRAME_MIN_SIZE + > + priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET])) { > + dev_err(state->dev, "frame has invalid number of bytes\n"); > + return false; > + } > + > + if ((priv->buf[SPS30_SERIAL_FRAME_ADR_OFFSET] != buf[SPS30_SERIAL_FRAME_ADR_OFFSET]) || > + (priv->buf[SPS30_SERIAL_FRAME_CMD_OFFSET] != buf[SPS30_SERIAL_FRAME_CMD_OFFSET])) { > + dev_err(state->dev, "frame has wrong ADR and CMD bytes\n"); > + return false; > + } > + > + if (priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]) { > + dev_err(state->dev, "frame with non-zero state received (0x%02x)\n", > + priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]); > + return false; > + } > + > + /* SOF, checksum and EOF are not checksummed */ > + chksum = sps30_serial_calc_chksum(priv->buf + 1, priv->num - 3); > + if (priv->buf[priv->num - 2] != chksum) { > + dev_err(state->dev, "frame integrity check failed\n"); > + return false; > + } > + > + return true; > +} > + > +static int sps30_serial_command(struct sps30_state *state, unsigned char cmd, > + const void *arg, size_t arg_size, void *rsp, size_t rsp_size) > +{ > + struct sps30_serial_priv *priv = state->priv; > + unsigned char buf[SPS30_SERIAL_MAX_BUF_SIZE]; > + int ret, size; > + > + size = sps30_serial_prep_frame(buf, cmd, arg, arg_size); > + ret = sps30_serial_xfer(state, buf, size); > + if (ret) > + return ret; > + > + if (!sps30_serial_frame_valid(state, buf)) > + return -EIO; > + > + if (rsp) { > + rsp_size = min_t(size_t, priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET], rsp_size); > + memcpy(rsp, &priv->buf[SPS30_SERIAL_FRAME_MISO_DATA_OFFSET], rsp_size); > + } > + > + return rsp_size; > +} > + > +static int sps30_serial_receive_buf(struct serdev_device *serdev, > + const unsigned char *buf, size_t size) > +{ > + struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev); > + struct sps30_serial_priv *priv; > + struct sps30_state *state; > + unsigned char byte; > + size_t i; > + > + if (!indio_dev) > + return 0; > + > + state = iio_priv(indio_dev); > + priv = state->priv; > + > + /* just in case device put some unexpected data on the bus */ > + if (priv->done) > + return size; > + > + /* wait for the start of frame */ > + if (!priv->num && size && buf[0] != SPS30_SERIAL_SOF_EOF) > + return 1; > + > + if (priv->num + size >= ARRAY_SIZE(priv->buf)) > + size = ARRAY_SIZE(priv->buf) - priv->num; > + > + for (i = 0; i < size; i++) { > + byte = buf[i]; > + /* remove stuffed bytes on-the-fly */ > + if (byte == SPS30_SERIAL_ESCAPE_CHAR) { > + priv->escaped = true; > + continue; > + } > + > + byte = sps30_serial_get_byte(priv->escaped, byte); > + if (priv->escaped && !byte) > + dev_warn(state->dev, "unrecognized escaped char (0x%02x)\n", byte); > + > + priv->buf[priv->num++] = byte; > + > + /* EOF received */ > + if (!priv->escaped && byte == SPS30_SERIAL_SOF_EOF) { > + if (priv->num < SPS30_SERIAL_FRAME_MIN_SIZE) > + continue; > + > + priv->done = true; > + complete(&priv->new_frame); > + i++; > + break; > + } > + > + priv->escaped = false; > + } > + > + return i; > +} > + > +static const struct serdev_device_ops sps30_serial_device_ops = { > + .receive_buf = sps30_serial_receive_buf, > + .write_wakeup = serdev_device_write_wakeup, > +}; > + > +static int sps30_serial_start_meas(struct sps30_state *state) > +{ > + /* request BE IEEE754 formatted data */ > + unsigned char buf[] = { 0x01, 0x03 }; > + > + return sps30_serial_command(state, SPS30_SERIAL_START_MEAS, buf, sizeof(buf), NULL, 0); > +} > + > +static int sps30_serial_stop_meas(struct sps30_state *state) > +{ > + return sps30_serial_command(state, SPS30_SERIAL_STOP_MEAS, NULL, 0, NULL, 0); > +} > + > +static int sps30_serial_reset(struct sps30_state *state) > +{ > + int ret; > + > + ret = sps30_serial_command(state, SPS30_SERIAL_RESET, NULL, 0, NULL, 0); > + msleep(500); > + > + return ret; > +} > + > +static int sps30_serial_read_meas(struct sps30_state *state, __be32 *meas, size_t num) > +{ > + int ret; > + > + /* measurements are ready within a second */ > + if (msleep_interruptible(1000)) > + return -EINTR; > + > + ret = sps30_serial_command(state, SPS30_SERIAL_READ_MEAS, NULL, 0, meas, num * sizeof(num)); > + if (ret < 0) > + return ret; > + /* if measurements aren't ready sensor returns empty frame */ > + if (ret == SPS30_SERIAL_FRAME_MIN_SIZE) > + return -ETIMEDOUT; > + if (ret != num * sizeof(*meas)) > + return -EIO; > + > + return 0; > +} > + > +static int sps30_serial_clean_fan(struct sps30_state *state) > +{ > + return sps30_serial_command(state, SPS30_SERIAL_CLEAN_FAN, NULL, 0, NULL, 0); > +} > + > +static int sps30_serial_read_cleaning_period(struct sps30_state *state, __be32 *period) > +{ > + unsigned char buf[] = { 0x00 }; > + int ret; > + > + ret = sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf), > + period, sizeof(*period)); > + if (ret < 0) > + return ret; > + if (ret != sizeof(*period)) > + return -EIO; > + > + return 0; > +} > + > +static int sps30_serial_write_cleaning_period(struct sps30_state *state, __be32 period) > +{ > + unsigned char buf[5] = { 0x00 }; > + > + memcpy(buf + 1, &period, sizeof(period)); > + > + return sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf), NULL, 0); > +} > + > +static int sps30_serial_show_info(struct sps30_state *state) > +{ > + /* extra nul byte just in case serial number isn't a valid string */ > + unsigned char buf[32 + 1] = { 0x00 }; > + struct device *dev = state->dev; > + int ret; > + > + /* tell device to return serial number */ > + buf[0] = 0x03; Bit odd when you just set it to 0 above. Maybe just set unsigned char buf[32 + 1] = { 0x03 }; and combine the comments? If everything else is fine, I can do that whilst applying. > + ret = sps30_serial_command(state, SPS30_SERIAL_DEV_INFO, buf, 1, buf, sizeof(buf) - 1); > + if (ret < 0) > + return ret; > + > + dev_info(dev, "serial number: %s\n", buf); > + > + ret = sps30_serial_command(state, SPS30_SERIAL_READ_VERSION, NULL, 0, buf, sizeof(buf) - 1); > + if (ret < 0) > + return ret; > + if (ret < 2) > + return -EIO; > + > + dev_info(dev, "fw version: %u.%u\n", buf[0], buf[1]); > + > + return 0; > +} > + > +static const struct sps30_ops sps30_serial_ops = { > + .start_meas = sps30_serial_start_meas, > + .stop_meas = sps30_serial_stop_meas, > + .read_meas = sps30_serial_read_meas, > + .reset = sps30_serial_reset, > + .clean_fan = sps30_serial_clean_fan, > + .read_cleaning_period = sps30_serial_read_cleaning_period, > + .write_cleaning_period = sps30_serial_write_cleaning_period, > + .show_info = sps30_serial_show_info, > +}; > + > +static int sps30_serial_probe(struct serdev_device *serdev) > +{ > + struct device *dev = &serdev->dev; > + struct sps30_serial_priv *priv; > + int ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + init_completion(&priv->new_frame); > + serdev_device_set_client_ops(serdev, &sps30_serial_device_ops); > + > + ret = devm_serdev_device_open(dev, serdev); > + if (ret) > + return ret; > + > + serdev_device_set_baudrate(serdev, 115200); > + serdev_device_set_flow_control(serdev, false); > + > + ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE); > + if (ret) > + return ret; > + > + return sps30_probe(dev, SPS30_SERIAL_DEV_NAME, priv, &sps30_serial_ops); > +} > + > +static const struct of_device_id sps30_serial_of_match[] = { > + { .compatible = "sensirion,sps30" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, sps30_serial_of_match); > + > +static struct serdev_device_driver sps30_serial_driver = { > + .driver = { > + .name = KBUILD_MODNAME, > + .of_match_table = sps30_serial_of_match, > + }, > + .probe = sps30_serial_probe, > +}; > +module_serdev_device_driver(sps30_serial_driver); > + > +MODULE_AUTHOR("Tomasz Duszynski "); > +MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor serial driver"); > +MODULE_LICENSE("GPL v2");