From 52302f87d0a126a34686f40cdd4ab28f9e824a68 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nuno=20S=C3=A1?= Date: Fri, 25 Feb 2022 14:01:28 +0100 Subject: [PATCH] iio: ABI: add ABI file for the LTC2688 DAC MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Define the sysfs interface for toggle or dither capable channels. Dither capable channels will have the extended interface: * out_voltageY_dither_en * out_voltageY_dither_raw * out_voltageY_dither_offset * out_voltageY_dither_raw_available * out_voltageY_dither_frequency * out_voltageY_dither_frequency_available * out_voltageY_dither_phase * out_voltageY_dither_phase_available Toggle enabled channels will have: * out_voltageY_toggle_en * out_voltageY_raw0 * out_voltageY_raw1 * out_voltageY_symbol The common interface present in all channels is: * out_voltageY_raw (not present in toggle enabled channels) * out_voltageY_raw_available * out_voltageY_powerdown * out_voltageY_scale * out_voltageY_offset * out_voltageY_calibbias * out_voltageY_calibscale Signed-off-by: Nuno Sá Link: https://lore.kernel.org/r/20220225130129.69-3-nuno.sa@analog.com Signed-off-by: Jonathan Cameron --- .../ABI/testing/sysfs-bus-iio-dac-ltc2688 | 86 ++++++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 87 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 b/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 new file mode 100644 index 0000000..1c35971 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 @@ -0,0 +1,86 @@ +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_en +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Dither enable. Write 1 to enable dither or 0 to disable it. This is useful + for changing the dither parameters. They way it should be done is: + + - disable dither operation; + - change dither parameters (eg: frequency, phase...); + - enabled dither operation + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_raw +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + This raw, unscaled value refers to the dither signal amplitude. + The same scale as in out_voltageY_raw applies. However, the + offset might be different as it's always 0 for this attribute. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_raw_available +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Available range for dither raw amplitude values. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_offset +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Offset applied to out_voltageY_dither_raw. Read only attribute + always set to 0. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_frequency +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Sets the dither signal frequency. Units are in Hz. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_frequency_available +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Returns the available values for the dither frequency. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_phase +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Sets the dither signal phase. Units are in Radians. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_dither_phase_available +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Returns the available values for the dither phase. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_toggle_en +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Toggle enable. Write 1 to enable toggle or 0 to disable it. This is + useful when one wants to change the DAC output codes. The way it should + be done is: + + - disable toggle operation; + - change out_voltageY_raw0 and out_voltageY_raw1; + - enable toggle operation. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_raw0 +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_raw1 +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + It has the same meaning as out_voltageY_raw. This attribute is + specific to toggle enabled channels and refers to the DAC output + code in INPUT_A (_raw0) and INPUT_B (_raw1). The same scale and offset + as in out_voltageY_raw applies. + +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_symbol +KernelVersion: 5.18 +Contact: linux-iio@vger.kernel.org +Description: + Performs a SW toggle. This attribute is specific to toggle + enabled channels and allows to toggle between out_voltageY_raw0 + and out_voltageY_raw1 through software. Writing 0 will select + out_voltageY_raw0 while 1 selects out_voltageY_raw1. diff --git a/MAINTAINERS b/MAINTAINERS index 7f2e55a..29f4b6d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11322,6 +11322,7 @@ M: Nuno Sá L: linux-iio@vger.kernel.org S: Supported W: http://ez.analog.com/community/linux-device-drivers +F: Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 F: drivers/iio/dac/ltc2688.c LTC2947 HARDWARE MONITOR DRIVER -- 2.7.4