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path: root/drivers/iio/adc/ad4695.c
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2025-05-21iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELSDavid Lechner
Rename AD4695_MAX_CHANNELS to AD4695_MAX_VIN_CHANNELS. It has been a point of confusion that this macro is only the voltage input channels and not all channels. Reviewed-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: Nuno Sá <nuno.sa@analog.com> Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250507-iio-introduce-iio_declare_buffer_with_ts-v6-4-4aee1b9f1b89@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-05-21iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TSDavid Lechner
Use IIO_DECLARE_DMA_BUFFER_WITH_TS() to declare the buffer that gets used with iio_push_to_buffers_with_ts(). This makes the code a bit easier to read and understand. Reviewed-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: Nuno Sá <nuno.sa@analog.com> Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250507-iio-introduce-iio_declare_buffer_with_ts-v6-3-4aee1b9f1b89@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-05-21iio: adc: ad4695: use u16 for buffer elementsDavid Lechner
Change the type of the buffer elements to u16 since we currently only support 16-bit word size. The code was originally written to also allow for 32-bit word size when oversampling is enabled, but so far, oversampling is only implemented when using SPI offload and therefore doesn't use this buffer. AD4695_MAX_CHANNEL_SIZE macro is dropped since it no longer adds any value. AD4695_MAX_CHANNELS + 2 is changed to AD4695_MAX_CHANNELS + 1 because previously we were overallocating. AD4695_MAX_CHANNELS is the number of of voltage channels and + 1 is for the temperature channel. Signed-off-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Trevor Gamblin <tgamblin@baylibre.com> Link: https://patch.msgid.link/20250428-iio-introduce-iio_declare_buffer_with_ts-v4-2-6f7f6126f1cb@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-05-21iio: adc: Use iio_push_to_buffers_with_ts() to provide length for runtime ↵Jonathan Cameron
checks. This new function allows us to perform debug checks in the helper to ensure that the overrun does not occur. Use it in all the simple cases where either a static buffer or a structure is used in the drivers. Reviewed-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250413103443.2420727-10-jic23@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-03-04iio: adc: ad4695: simplify getting oversampling_ratioDavid Lechner
We already have a local variable that holds a pointer to st->channels_cfg[chan->scan_index]. Use that to simplify the code. Signed-off-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20250218-iio-adc-ad4695-fix-out-of-bounds-array-access-v1-2-57fef8c7a3fd@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-03-04iio: adc: ad4695: fix out of bounds array accessDavid Lechner
Fix some out of bounds array access of st->channels_cfg in the ad4695 driver. This array only has elements for voltage channels, but it was also being accessed for the temperature channel in a few cases causing reading past the end of the array. In some cases, this was harmless because the value was read but not used. However, the in_temp_sampling_frequency attribute shares code with the in_voltageY_sampling_frequency attributes and was trying to read the oversampling ratio from the st->channels_cfg array. This resulted in a garbage value being used in the calculation and the resulting in_temp_sampling_frequency value was incorrect. To fix, make sure we always check that we are dealing with a voltage channel before accessing the st->channels_cfg array and use an oversampling ratio of 1 for the temperature channel (multiplicative identity value) since that channel doesn't support oversampling. Fixes: 67d63185db79 ("iio: adc: ad4695: add offload-based oversampling support") Signed-off-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20250218-iio-adc-ad4695-fix-out-of-bounds-array-access-v1-1-57fef8c7a3fd@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-02-17iio: adc: ad4695: Stop using iio_device_claim_direct_scoped()Jonathan Cameron
This complex cleanup.h use case of conditional guards has proved to be more trouble that it is worth in terms of false positive compiler warnings and hard to read code. Move directly to the new claim/release_direct() that allow sparse to check for unbalanced context. In some cases code is factored out to utility functions that can do a direct return with the claim and release around the call. Reviewed-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Nuno Sa <nuno.sa@analog.com> Link: https://patch.msgid.link/20250209180624.701140-12-jic23@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-02-11iio: adc: ad4695: add offload-based oversampling supportTrevor Gamblin
Add support for the ad4695's oversampling feature when SPI offload is available. This allows the ad4695 to set oversampling ratios on a per-channel basis, raising the effective-number-of-bits from 16 (OSR == 1) to 17 (4), 18 (16), or 19 (64) for a given sample (i.e. one full cycle through the auto-sequencer). The logic for reading and writing sampling frequency for a given channel is also adjusted based on the current oversampling ratio. The non-offload case isn't supported as there isn't a good way to trigger the CNV pin in this mode. Support could be added in the future if a use-case arises. Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: Nuno Sa <nuno.sa@analog.com> Tested-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250109-ad4695-oversampling-v2-1-a46ac487082c@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-02-11iio: adc: ad4695: Add support for SPI offloadDavid Lechner
Add support for SPI offload to the ad4695 driver. SPI offload allows sampling data at the max sample rate (500kSPS or 1MSPS). This is developed and tested against the ADI example FPGA design for this family of ADCs [1]. [1]: http://analogdevicesinc.github.io/hdl/projects/ad469x_fmc/index.html Reviewed-by: Nuno Sa <nuno.sa@analog.com> Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-14-e48a489be48c@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-02-03iio: adc: ad4695: add custom regmap bus callbacksTrevor Gamblin
Add a custom implementation of regmap read/write callbacks using the SPI bus. This allows them to be performed at a lower SCLK rate than data reads. Previously, all SPI transfers were being performed at a lower speed, but with this change sample data is read at the max bus speed while the register reads/writes remain at the lower rate. Also remove .can_multi_write from the AD4695 driver's regmap_configs, as this isn't implemented or needed. For some background context, see: https://lore.kernel.org/linux-iio/20241028163907.00007e12@Huawei.com/ Suggested-by: David Lechner <dlechner@baylibre.com> Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: David Lechner <dlechner@baylibre.com> Tested-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20241113-tgamblin-ad4695_improvements-v2-3-b6bb7c758fc4@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-02-03iio: adc: ad4695: make ad4695_exit_conversion_mode() more robustTrevor Gamblin
Ensure that conversion mode is successfully exited when the command is issued by adding an extra transfer beforehand, matching the minimum CNV high and low times from the AD4695 datasheet. The AD4695 has a quirk where the exit command only works during a conversion, so guarantee this happens by triggering a conversion in ad4695_exit_conversion_mode(). Then make this even more robust by ensuring that the exit command is run at AD4695_REG_ACCESS_SCLK_HZ rather than the bus maximum. Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: David Lechner <dlechner@baylibre.com> Tested-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20241113-tgamblin-ad4695_improvements-v2-2-b6bb7c758fc4@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-01-13Merge 6.13-rc4 into char-misc-nextGreg Kroah-Hartman
We need the IIO fixes in here as well, and it resolves a merge conflict in: drivers/iio/adc/ti-ads1119.c Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-07iio: adc: ad4695: move dt-bindings headerDavid Lechner
Move the dt-bindings header file to the include/dt-bindings/iio/adc/ directory. ad4695 is an ADC driver, so it should be in the adc/ subdirectory for better organization. Previously, it was in the iio/ subdirectory. Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20241113-iio-adc-ad4695-move-dt-bindings-header-v1-1-aba1f0f9b628@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-12-07iio: adc: ad4695: fix buffered read, single sample timingsTrevor Gamblin
Modify ad4695_buffer_preenable() by adding an extra SPI transfer after each data read to help ensure that the timing requirement between the last SCLK rising edge and the next CNV rising edge is met. This requires a restructure of the buf_read_xfer array in ad4695_state. Also define AD4695_T_SCK_CNV_DELAY_NS to use for each added transfer. Without this change it is possible for the data to become corrupted on sequential buffered reads due to the device not properly exiting conversion mode. Similarly, make adjustments to ad4695_read_one_sample() so that timings are respected, and clean up the function slightly in the process. Fixes: 6cc7e4bf2e08 ("iio: adc: ad4695: implement triggered buffer") Co-developed-by: David Lechner <dlechner@baylibre.com> Signed-off-by: David Lechner <dlechner@baylibre.com> Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com> Reviewed-by: David Lechner <dlechner@baylibre.com> Tested-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20241113-tgamblin-ad4695_improvements-v2-1-b6bb7c758fc4@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-09-03iio: adc: ad4695: implement calibration supportDavid Lechner
The AD4695 has a calibration feature that allows the user to compensate for variations in the analog front end. This implements this feature in the driver using the standard `calibgain` and `calibbias` attributes. Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20240820-ad4695-gain-offset-v1-2-c8f6e3b47551@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-09-03iio: adc: ad4695: add 2nd regmap for 16-bit registersDavid Lechner
The AD4695 and similar chips have some multibyte registers that have to be read/written in a single operation. So we need to add a 2nd regmap for these registers. These registers are removed from the 8-bit regmap allowable ranges and AD4695_MAX_REG is dropped since it would be ambiguous now. debugfs register access is also updated to automatically use the correct regmap depending on the register address. Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20240820-ad4695-gain-offset-v1-1-c8f6e3b47551@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-08-17iio: adc: ad4695: implement triggered bufferDavid Lechner
This implements buffered reads for the ad4695 driver using the typical triggered buffer implementation, including adding a soft timestamp channel. The chip has 4 different modes for doing conversions. The driver is using the advanced sequencer mode since that is the only mode that allows individual configuration of all aspects each channel (e.g. bipolar config currently and oversampling to be added in the future). Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20240813-iio-adc-ad4695-buffered-read-v2-1-9bb19fc1924b@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-08-03iio: adc: ad4695: Add driver for AD4695 and similar ADCsDavid Lechner
This is a new driver for Analog Devices Inc. AD4695 and similar ADCs. The initial driver supports initializing the chip including configuring all possible LDO and reference voltage sources as well as any possible voltage input channel wiring configuration. Only the 4-wire SPI wiring mode where the CNV pin is tied to the CS pin is supported at this time. And reading sample data from the ADC can only be done in direct mode for now. Co-developed-by: Ramona Gradinariu <ramona.gradinariu@analog.com> Signed-off-by: Ramona Gradinariu <ramona.gradinariu@analog.com> Signed-off-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Nuno Sa <nuno.sa@analog.com> Link: https://patch.msgid.link/20240711-iio-adc-ad4695-v4-2-c31621113b57@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>