From patchwork Wed Feb 2 14:01:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12732969 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 2B5A4C433F5 for ; Wed, 2 Feb 2022 14:02:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230213AbiBBOCL (ORCPT ); Wed, 2 Feb 2022 09:02:11 -0500 Received: from relay12.mail.gandi.net ([217.70.178.232]:52503 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbiBBOCK (ORCPT ); Wed, 2 Feb 2022 09:02:10 -0500 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 95CA9200010; Wed, 2 Feb 2022 14:02:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1643810529; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=XT2yXScjF+TdX6tS7FnGG5ieuHrEO/BJ/KLLpXdWdOw=; b=S3grmL3vQ8KKzLVxBqxxfH2CMqrisojfyl2pRMqcLzPvCH6ylDWoj07lLE5pn1tVJD7NST Gz51Xuj/W9KcWWzelqv80u6LRuAopUgn3BY0PJcqrmYQu2NRlnIedtuc+QBfap5KZHJEXS 884zF4ISan28td6Ai4bG12b2MM6hVRfHOP5WsWscdvRh4gQ7nSi/WnM+hzmcC/ofnoqV1S wuHapKUcMX8tffombVlLi02YwT9uLWo2C69UA3kqtfkV0e5W9qYnHk6k68dn6q2LSTId+U XG0WsfxI7l9gdNpUGVLUVPDSuUglePAogITOqVf+nFmPBGIQha3p6lXdCMYApA== From: Miquel Raynal To: linux-iio@vger.kernel.org, Jonathan Cameron , Lars-Peter Clausen Cc: Thomas Petazzoni , Alexandru Ardelean , Miquel Raynal Subject: [PATCH v2 00/12] Miscellaneous IIO core enhancements Date: Wed, 2 Feb 2022 15:01:56 +0100 Message-Id: <20220202140208.391394-1-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Hello, As part of a previous discussion with Jonathan (I know, it was three months ago, sorry for the delay :-$), it appeared necessary to do a little bit of cleanup in the IIO core and at least provide a little bit more documentation for developers diving into the IIO subsystem for the first time. My first move was to write a blog post trying to explain (from my point of view but with the review of Jonathan) what is necessary to understand when writing and IIO kernel driver: https://bootlin.com/blog/the-backbone-of-a-linux-industrial-i-o-driver/ Here is now the second halve of this work, with few things that I tried to address. * The currentmode indio_dev entry was misused by several device drivers, I tried to understand which ones were wrong (there are two still accessing this variable left, I decided not to touch them because I think it is legitimate) and I tried to find an alternative. * Then, I tried to make new accesses to this variable harder in order to avoid future mistakes, by creating a helper to read it from outside the core and moving it to the opaque structure. * I continued with the IIO modes which are completely undocumented. Following a few exchanges with Jonathan, I tried to take most of this discussion and put it into a kernel doc header. * When doing the above task, I realized that there was a particular case handled for kfifo buffers which I tried to simplify, but if this is a mistake, I'll just drop the patch. Hope this will help! Cheers, Miquèl Changes in v2: * Added Alexandru Reviewed-by when relevant. * Indicated that "modes" is a bitmask as suggested. * Added a mention in the "modes" kdoc about the function that could alter its content in the core. * Added more driver maintainers in Cc. * Avoided deleting the INDIO_BUFFER_TRIGGERED mode from kfifos. * Dropped entirely the currentmode setter helper. * Avoided using the currentmode getter from places where we have access to the opaque structure (ie. from the core itself). * Added a patch to move the iio_buffer_enabled() definition in the core as it cannot be inlined anymore. * Dropped completely the use of the mlock lock form the st-sensor drivers by inserting an additional local lock when this was needed. Hopefully I didn't fail that, this will need testing. * Reworded the modes kdoc as advised by Jonathan. Miquel Raynal (12): iio: core: Enhance the kernel doc of modes and currentmodes iio_dev entries iio: magnetometer: rm3100: Stop abusing the ->currentmode iio: adc: stm32-dfsdm: Avoid dereferencing ->currentmode iio: st_sensors: Drop the protection on _avail functions iio: st_sensors: Add a local lock for protecting odr iio: st_sensors: Stop abusing mlock to ensure internal coherency iio: st_sensors: Use iio_device_claim/release_direct_mode() when relevant iio: Un-inline iio_buffer_enabled() iio: core: Hide read accesses to iio_dev->currentmode iio: core: Move the currentmode entry to the opaque structure iio: core: Simplify the registration of kfifo buffers iio: core: Clarify the modes drivers/iio/accel/bmc150-accel-core.c | 4 +- drivers/iio/accel/fxls8962af-core.c | 1 - drivers/iio/accel/sca3000.c | 1 - drivers/iio/accel/ssp_accel_sensor.c | 1 - drivers/iio/accel/st_accel_core.c | 5 +- drivers/iio/adc/at91-sama5d2_adc.c | 4 +- drivers/iio/adc/ina2xx-adc.c | 1 - drivers/iio/adc/stm32-dfsdm-adc.c | 5 +- drivers/iio/adc/ti_am335x_adc.c | 4 +- drivers/iio/buffer/kfifo_buf.c | 10 +-- .../cros_ec_sensors/cros_ec_sensors_core.c | 3 +- drivers/iio/common/scmi_sensors/scmi_iio.c | 1 - .../iio/common/st_sensors/st_sensors_core.c | 60 +++++++++-------- drivers/iio/gyro/ssp_gyro_sensor.c | 1 - drivers/iio/gyro/st_gyro_core.c | 5 +- drivers/iio/health/max30100.c | 1 - drivers/iio/health/max30102.c | 1 - .../iio/imu/inv_icm42600/inv_icm42600_accel.c | 1 - .../iio/imu/inv_icm42600/inv_icm42600_gyro.c | 1 - .../iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 1 - drivers/iio/industrialio-buffer.c | 12 ++-- drivers/iio/industrialio-core.c | 27 ++++++++ drivers/iio/industrialio-trigger.c | 2 +- drivers/iio/light/apds9960.c | 1 - drivers/iio/magnetometer/rm3100-core.c | 15 +---- drivers/iio/magnetometer/st_magn_core.c | 5 +- drivers/iio/pressure/st_pressure_core.c | 8 +-- .../staging/iio/impedance-analyzer/ad5933.c | 1 - include/linux/iio/common/st_sensors.h | 3 + include/linux/iio/iio-opaque.h | 4 ++ include/linux/iio/iio.h | 67 +++++++++++++++---- include/linux/iio/kfifo_buf.h | 5 +- 32 files changed, 149 insertions(+), 112 deletions(-)