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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4AA0DEB64DC for ; Tue, 11 Jul 2023 10:14:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230047AbjGKKOa (ORCPT ); Tue, 11 Jul 2023 06:14:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229939AbjGKKO3 (ORCPT ); Tue, 11 Jul 2023 06:14:29 -0400 Received: from smtp28.bhosted.nl (smtp28.bhosted.nl [IPv6:2a02:9e0:8000::40]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BCF7136 for ; Tue, 11 Jul 2023 03:14:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonic.nl; s=202111; h=content-transfer-encoding:mime-version:message-id:date:subject:cc:to:from: from; bh=HKlgnykOnFg9SknTx7FMyWuQFrDaMQk/32MCbOChNI4=; b=T15BVvnEJBkTOo9yT6EHD9ta9Wgkqo3S8+BzK6EcDV/JPnNhgycTl4lqdw2lFYTTtDrAuKF6TQHiu haXXglCr3zTOUH34j/ta0aM4CQGS0AvRaNj9vgqPo7ttHQyF+M7FaiX2YgEKA1way5qcFleAFI1T3c nIDRlGf4dymGL5UAJblFfthVsMmyR2MIqNmdLS82g2MbgSf5oZD37bzuz5kHOTE1lmVS2jnbAlEYmJ Pj+vhUepqEBcqmvRP7ocfUMLnwGvGXXTNYFFk8xIlWxEtbyj7oXToBZNGB22NNmVB7TpiPIoOySRcg GN02bBfmUFYPNFZdlDuv8VB1dcGbsWw== X-MSG-ID: b56f306b-1fd3-11ee-9499-0050569d11ae From: Roan van Dijk To: jic23@kernel.org Cc: lars@metafoo.de, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Roan van Dijk Subject: [PATCH v2] iio: chemical: scd4x: Add pressure compensation Date: Tue, 11 Jul 2023 12:14:19 +0200 Message-Id: <20230711101419.2065107-1-roan@protonic.nl> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org This patch adds pressure compensation to the scd4x driver. The pressure can be written to the sensor in hPa. The pressure will be compensated internally by the sensor. Signed-off-by: Roan van Dijk --- Changes since v2: - Fix for kernel test robot errors of uninitialized symbols - Changed pressure compensation to output channel instead of a channel with calibbias - Pressure can now be compensated during measurements drivers/iio/chemical/scd4x.c | 79 +++++++++++++++++++++++++++++++++--- 1 file changed, 73 insertions(+), 6 deletions(-) diff --git a/drivers/iio/chemical/scd4x.c b/drivers/iio/chemical/scd4x.c index a4f22d926400..4bb5d215c54c 100644 --- a/drivers/iio/chemical/scd4x.c +++ b/drivers/iio/chemical/scd4x.c @@ -36,6 +36,8 @@ #define SCD4X_WRITE_BUF_SIZE 5 #define SCD4X_FRC_MIN_PPM 0 #define SCD4X_FRC_MAX_PPM 2000 +#define SCD4X_PRESSURE_COMP_MIN_MBAR 700 +#define SCD4X_PRESSURE_COMP_MAX_MBAR 1200 #define SCD4X_READY_MASK 0x01 /*Commands SCD4X*/ @@ -45,6 +47,8 @@ enum scd4x_cmd { CMD_STOP_MEAS = 0x3f86, CMD_SET_TEMP_OFFSET = 0x241d, CMD_GET_TEMP_OFFSET = 0x2318, + CMD_SET_AMB_PRESSURE = 0xe000, + CMD_GET_AMB_PRESSURE = 0xe000, CMD_FRC = 0x362f, CMD_SET_ASC = 0x2416, CMD_GET_ASC = 0x2313, @@ -137,7 +141,8 @@ static int scd4x_read(struct scd4x_state *state, enum scd4x_cmd cmd, * Measurement needs to be stopped before sending commands. * Except for reading measurement and data ready command. */ - if ((cmd != CMD_GET_DATA_READY) && (cmd != CMD_READ_MEAS)) { + if ((cmd != CMD_GET_DATA_READY) && (cmd != CMD_READ_MEAS) && + (cmd != CMD_GET_AMB_PRESSURE)) { ret = scd4x_send_command(state, CMD_STOP_MEAS); if (ret) return ret; @@ -166,7 +171,8 @@ static int scd4x_read(struct scd4x_state *state, enum scd4x_cmd cmd, } /* start measurement */ - if ((cmd != CMD_GET_DATA_READY) && (cmd != CMD_READ_MEAS)) { + if ((cmd != CMD_GET_DATA_READY) && (cmd != CMD_READ_MEAS) && + (cmd != CMD_GET_AMB_PRESSURE)) { ret = scd4x_send_command(state, CMD_START_MEAS); if (ret) return ret; @@ -188,9 +194,11 @@ static int scd4x_write(struct scd4x_state *state, enum scd4x_cmd cmd, uint16_t a buf[4] = crc; /* measurement needs to be stopped before sending commands */ - ret = scd4x_send_command(state, CMD_STOP_MEAS); - if (ret) - return ret; + if (cmd != CMD_SET_AMB_PRESSURE) { + ret = scd4x_send_command(state, CMD_STOP_MEAS); + if (ret) + return ret; + } /* execution time */ msleep_interruptible(500); @@ -200,7 +208,7 @@ static int scd4x_write(struct scd4x_state *state, enum scd4x_cmd cmd, uint16_t a return ret; /* start measurement, except for forced calibration command */ - if (cmd != CMD_FRC) { + if ((cmd != CMD_FRC) && (cmd != CMD_SET_AMB_PRESSURE)) { ret = scd4x_send_command(state, CMD_START_MEAS); if (ret) return ret; @@ -338,6 +346,18 @@ static int scd4x_read_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_RAW: + if (chan->output) { + mutex_lock(&state->lock); + ret = scd4x_read(state, CMD_GET_AMB_PRESSURE, &tmp, sizeof(tmp)); + mutex_unlock(&state->lock); + + if (ret) + return ret; + + *val = be16_to_cpu(tmp); + return IIO_VAL_INT; + } + ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; @@ -386,6 +406,25 @@ static int scd4x_read_raw(struct iio_dev *indio_dev, } } +static const int scd4x_pressure_calibbias_available[] = { + SCD4X_PRESSURE_COMP_MIN_MBAR, 1, SCD4X_PRESSURE_COMP_MAX_MBAR, +}; + +static int scd4x_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_RAW: + *vals = scd4x_pressure_calibbias_available; + *type = IIO_VAL_INT; + + return IIO_AVAIL_RANGE; + } + + return -EINVAL; +} + + static int scd4x_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { @@ -399,6 +438,21 @@ static int scd4x_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const mutex_unlock(&state->lock); return ret; + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_PRESSURE: + if (val < SCD4X_PRESSURE_COMP_MIN_MBAR || + val > SCD4X_PRESSURE_COMP_MAX_MBAR) + return -EINVAL; + + mutex_lock(&state->lock); + ret = scd4x_write(state, CMD_SET_AMB_PRESSURE, val); + mutex_unlock(&state->lock); + + return ret; + default: + return -EINVAL; + } default: return -EINVAL; } @@ -503,9 +557,22 @@ static const struct iio_info scd4x_info = { .attrs = &scd4x_attr_group, .read_raw = scd4x_read_raw, .write_raw = scd4x_write_raw, + .read_avail = scd4x_read_avail, }; static const struct iio_chan_spec scd4x_channels[] = { + { + /* + * this channel is special in a sense we are pretending that + * sensor is able to change measurement chamber pressure but in + * fact we're just setting pressure compensation value + */ + .type = IIO_PRESSURE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW), + .output = 1, + .scan_index = -1, + }, { .type = IIO_CONCENTRATION, .channel2 = IIO_MOD_CO2, -- 2.39.2