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Fri, 8 Dec 2017 15:50:22 +0100 Received: from localhost (10.201.23.162) by webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.352.0; Fri, 8 Dec 2017 15:50:22 +0100 From: Arnaud Pouliquen To: Rob Herring , Mark Rutland , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Jaroslav Kysela , Takashi Iwai , Liam Girdwood , Mark Brown Subject: [PATCH v7 02/13] docs: driver-api: add iio hw consumer section Date: Fri, 8 Dec 2017 15:49:15 +0100 Message-ID: <1512744566-13233-3-git-send-email-arnaud.pouliquen@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1512744566-13233-1-git-send-email-arnaud.pouliquen@st.com> References: <1512744566-13233-1-git-send-email-arnaud.pouliquen@st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.23.162] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-12-08_08:, , signatures=0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171208_065054_992238_664216D9 X-CRM114-Status: GOOD ( 13.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, alsa-devel@alsa-project.org, Alexandre Torgue , linux-iio@vger.kernel.org, arnaud.pouliquen@st.com, Maxime Coquelin , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This adds a section about the Hardware consumer API of the IIO subsystem to the driver API documentation. Signed-off-by: Arnaud Pouliquen Reviewed-by: Jonathan Cameron --- Documentation/driver-api/iio/hw-consumer.rst | 51 ++++++++++++++++++++++++++++ Documentation/driver-api/iio/index.rst | 1 + 2 files changed, 52 insertions(+) create mode 100644 Documentation/driver-api/iio/hw-consumer.rst diff --git a/Documentation/driver-api/iio/hw-consumer.rst b/Documentation/driver-api/iio/hw-consumer.rst new file mode 100644 index 0000000..8facce6 --- /dev/null +++ b/Documentation/driver-api/iio/hw-consumer.rst @@ -0,0 +1,51 @@ +=========== +HW consumer +=========== +An IIO device can be directly connected to another device in hardware. in this +case the buffers between IIO provider and IIO consumer are handled by hardware. +The Industrial I/O HW consumer offers a way to bond these IIO devices without +software buffer for data. The implementation can be found under +:file:`drivers/iio/buffer/hw-consumer.c` + + +* struct :c:type:`iio_hw_consumer` — Hardware consumer structure +* :c:func:`iio_hw_consumer_alloc` — Allocate IIO hardware consumer +* :c:func:`iio_hw_consumer_free` — Free IIO hardware consumer +* :c:func:`iio_hw_consumer_enable` — Enable IIO hardware consumer +* :c:func:`iio_hw_consumer_disable` — Disable IIO hardware consumer + + +HW consumer setup +================= + +As standard IIO device the implementation is based on IIO provider/consumer. +A typical IIO HW consumer setup looks like this:: + + static struct iio_hw_consumer *hwc; + + static const struct iio_info adc_info = { + .read_raw = adc_read_raw, + }; + + static int adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) + { + ret = iio_hw_consumer_enable(hwc); + + /* Acquire data */ + + ret = iio_hw_consumer_disable(hwc); + } + + static int adc_probe(struct platform_device *pdev) + { + hwc = devm_iio_hw_consumer_alloc(&iio->dev); + } + +More details +============ +.. kernel-doc:: include/linux/iio/hw-consumer.h +.. kernel-doc:: drivers/iio/buffer/industrialio-hw-consumer.c + :export: + diff --git a/Documentation/driver-api/iio/index.rst b/Documentation/driver-api/iio/index.rst index e5c3922..7fba341 100644 --- a/Documentation/driver-api/iio/index.rst +++ b/Documentation/driver-api/iio/index.rst @@ -15,3 +15,4 @@ Contents: buffers triggers triggered-buffers + hw-consumer