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path: root/drivers/iio/adc/ti-ads7950.c
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2020-07-13Replace HTTP links with HTTPS ones: drivers/iioAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-14iio: remove explicit IIO device parent assignmentAlexandru Ardelean
This patch applies the semantic patch: @@ expression I, P, SP; @@ I = devm_iio_device_alloc(P, SP); ... - I->dev.parent = P; It updates 302 files and does 307 deletions. This semantic patch also removes some comments like '/* Establish that the iio_dev is a child of the i2c device */' But this is is only done in case where the block is left empty. The patch does not seem to cover all cases. It looks like in some cases a different variable is used in some cases to assign the parent, but it points to the same reference. In other cases, the block covered by ... may be just too big to be covered by the semantic patch. However, this looks pretty good as well, as it does cover a big bulk of the drivers that should remove the parent assignment. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-12-15iio: adc: ti-ads7950: Fix a typo in an error messageChristophe JAILLET
Fix a typo: s/get get/to get/ Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-04-04iio: adc: ti-ads7950: add GPIO supportJustin Chen
The ADS79XX has GPIO pins that can be used. Add support for the GPIO pins using the GPIO chip framework. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-04-04iio: adc: ti-ads7950: Fix improper use of mlockJustin Chen
Indio->mlock is used for protecting the different iio device modes. It is currently not being used in this way. Replace the lock with an internal lock specifically used for protecting the SPI transfer buffer. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-09-22iio: adc: ti-ads7950: use SPI_CS_WORD to reduce CPU usageDavid Lechner
This changes how the SPI message for the triggered buffer is setup in the TI ADS7950 A/DC driver. By using the SPI_CS_WORD flag, we can read multiple samples in a single SPI transfer. If the SPI controller supports DMA transfers, we can see a significant reduction in CPU usage. For example, on an ARM9 system running at 456MHz reading just 4 channels at 100Hz: before this change, top shows the CPU usage of the IRQ thread of this driver to be ~7.7%. After this change, the CPU usage drops to ~3.8%. The use of big-endian for the raw data was cargo culted from another driver when this driver was originally written. It used an SPI word size of 8 bits and big-endian byte ordering to effectively emulate 16 bit words. Now, in order to inject a CS toggle between each word, we need to use the correct word size, otherwise we would get a CS toggle half way through each word 16-bit. The SPI subsystem uses CPU byte ordering for multi-byte words. So, the data we get back from the SPI is going to be CPU endian now no matter what. Converting that to big endian will just add overhead on little endian systems so we opt to change the raw data format from big endian to CPU endian. There is a small risk that this could break some lazy userspace programs that use the raw data without checking the data format. We can address this if/when it actually comes up. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-07-23iio: adc: ti-ads7950: allow simultaneous use of buffer and direct modeDavid Lechner
This modifies the TI ADS7950 A/DC driver to allow the simultaneous use of both the triggered buffer and reading channels directly (via in- kernel API or sysfs). The use case for this is on LEGO MINDSTORMS EV3. Two of the voltage channels are used in-kernel by a power supply driver, which reads the values using iio_read_channel_processed(). These channels are only read at a slow rate (<= 1Hz). However, we want to be able to read 12 other channels at the same time using the triggered buffer at a high rate (>= 100Hz). Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-07-23iio: adc: ti-ads7950: use SPDX-License-IdentifierDavid Lechner
This updates the ti-ads7950.c file to use SPDX-License-Identifier instead of more verbose license text. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-08-22iio:adc: drop assign iio_info.driver_module and iio_trigger_ops.ownerJonathan Cameron
The equivalent of both of these are now done via macro magic when the relevant register calls are made. The actual structure elements will shortly go away. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-08-20iio: adc: ti-ads7950: Allow to use on ACPI platformsAndy Shevchenko
ACPI enabled platforms do not have a mean of regulators. Instead we use hard coded voltage value for reference pin. When value is 0 (default) we fall back to request a regulator. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-08-09iio: adc: ti-ads7950: Add OF device ID tableAndy Shevchenko
The driver doesn't have a struct of_device_id table but supported devices are registered via Device Trees. This is working on the assumption that a SPI device registered via OF will always match a legacy SPI device ID and that the MODALIAS reported will always be of the form spi:<device>. There is an ACPI method to enumerate such devices via specific ACPI ID and use of compatible strings. It will not work for the drivers which have no OF match ID table present. Besides this could change in the future so the correct approach is to have an OF device ID table if the devices are registered via OF. Tested-by: David Lechner <david@lechnology.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-01-15iio: adc: ti-ads7950: Change regulator matching string to "vref"David Lechner
This changes the reference voltage regulator matching string from "refin" to "vref". This is to be consistent with other A/DC chips that also use "vref-supply" in their device tree bindings. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-01-15iio: adc: ti-ads7950: Drop "ti-" prefix from module nameDavid Lechner
This drops the "ti-" prefix from the module name. It makes the module name consistent with other iio ti-ads* drivers and it makes the driver work with device tree (the spi subsystem drops the "ti," prefix when matching compatible strings from device tree). Tested working on LEGO MINDSTORMS EV3 with the following device tree node: adc@3 { compatible = "ti,ads7957"; reg = <3>; #io-channel-cells = <1>; spi-max-frequency = <10000000>; vref-supply = <&adc_ref>; }; Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-12-03iio: adc: New driver for TI ADS7950 chipsDavid Lechner
This adds a new driver for the TI ADS7950 family of ADC chips. These communicate using SPI and come in 8/10/12-bit and 4/8/12/16 channel varieties. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>