linux/drivers/staging/iio/resolver, branch master

iio: resolver: ad2s1210: move out of staging

2023-10-12T08:20:50Z

This moves the ad2s1210 resolver driver out of staging. The driver has been fixed up and is ready to graduate. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231010-ad2s1210-mainline-v5-4-35a0f6ffa04a@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: simplify code with guard(mutex)

2023-10-12T08:00:58Z

We can simplify the code and get rid of most of the gotos by using guard(mutex) from cleanup.h. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231010-ad2s1210-mainline-v5-3-35a0f6ffa04a@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: clear faults after soft reset

2023-10-12T07:59:13Z

When a software reset is performed on the AD2S1210 to make the selected excitation frequency take effect, it always triggers faults on the input signals because the output signal is interrupted momentarily. So we need to clear the faults after the software reset to avoid triggering fault events the next time a sample is read. The datasheet specifies a time t[track] in Table 27 that specifies the settle time in milliseconds after a reset depending on the selected resolution. This is used in the driver to add an appropriate delay. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231010-ad2s1210-mainline-v5-2-35a0f6ffa04a@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: refactor sample toggle

2023-10-12T07:56:08Z

This refactors the sample line toggle in the ad2s1210 resolver driver to a separate function. The sample has some timing requirements, so this ensures that it is always done the same way, both in the existing call sites and any future usage. Previously, the sample line was kept on for the duration of the read, but this is not necessary. Data is latched in on the rising edge and after the specified delay the state of the sample line does not matter. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231010-ad2s1210-mainline-v5-1-35a0f6ffa04a@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: remove fault attribute

2023-10-11T14:54:41Z

Faults have been converted to events and we are now polling the fault register each time we read a sample, so we no longer need the fault attribute. This attribute was not suitable for promotion out of staging anyway since it was returning multiple values in a single attribute. The fault clearing feature should not be needed unless we need to support the fault output pins on the chip which is not currently supported. So we can add this feature back in if we need it later. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-16-ec00746840fc@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: add label attribute support

2023-10-11T14:54:41Z

The ad2s1210 resolver driver has quite a few channels, mostly for internal signals for event support. This makes it difficult to know which channel is which. This patch adds a label attribute to the channels to make it easier to identify them. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-15-ec00746840fc@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: add register/fault support summary

2023-10-11T14:54:41Z

The ad2s1210 driver shoe-horns the register and fault support into IIO events. The mapping between the registers/faults and the events is not obvious. To save users from having to read the entire driver to figure out how to use it, add a summary of the register/fault support to the top of the file. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-14-ec00746840fc@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: implement fault events

2023-10-11T14:54:41Z

When reading the position and velocity on the AD2S1210, there is also a 3rd byte following the two data bytes that contains the fault flag bits. This patch adds support for reading this byte and generating events when faults occur. The faults are mapped to various channels and event type in order to have a unique event for each fault. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-13-ec00746840fc@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: rename DOS reset min/max attrs

2023-10-11T14:54:41Z

The AD2S1210 has a programmable threshold for the degradation of signal (DOS) mismatch fault. This fault is triggered when the difference in amplitude between the sine and cosine inputs exceeds the threshold. The DOS reset min/max registers on the chip provide initial values for internal tracking of the min/max of the monitor signal after the fault register is cleared. This patch converts the custom device DOS reset min/max threshold attributes custom event attributes on the monitor signal channel. The attributes now use millivolts instead of the raw register value in accordance with the IIO ABI. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-11-ec00746840fc@baylibre.com Signed-off-by: Jonathan Cameron

staging: iio: resolver: ad2s1210: convert DOS mismatch threshold to event attr

2023-10-11T14:54:41Z

The AD2S1210 has a programmable threshold for the degradation of signal (DOS) mismatch fault. This fault is triggered when the difference in voltage between the sine and cosine inputs exceeds the threshold. In other words, when the magnitude of sine and cosine inputs are equal, the AC component of the monitor signal is zero and when the magnitudes of the sine and cosine inputs are not equal, the AC component of the monitor signal is the difference between the sine and cosine inputs. So the fault occurs when the magnitude of the AC component of the monitor signal exceeds the DOS mismatch threshold voltage. This patch converts the custom device DOS mismatch threshold attribute to an event magnitude attribute on the monitor signal channel. The attribute now uses millivolts instead of the raw register value in accordance with the IIO ABI. Emitting the event will be implemented in a later patch. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-10-ec00746840fc@baylibre.com Signed-off-by: Jonathan Cameron