> -----Original Message----- > From: Tinaco, Mariel > Sent: Monday, July 8, 2024 7:32 AM > To: Jonathan Cameron <jic23@xxxxxxxxxx> > Cc: linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; Lars-Peter Clausen <lars@xxxxxxxxxx>; Rob Herring > <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>; Conor Dooley > <conor+dt@xxxxxxxxxx>; Liam Girdwood <lgirdwood@xxxxxxxxx>; Mark Brown > <broonie@xxxxxxxxxx>; Hennerich, Michael <Michael.Hennerich@xxxxxxxxxx>; > Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>; Dimitri Fedrau > <dima.fedrau@xxxxxxxxx>; Guenter Roeck <linux@xxxxxxxxxxxx> > Subject: RE: [PATCH 2/2] iio: dac: support the ad8460 Waveform DAC > > > > > -----Original Message----- > > From: Jonathan Cameron <jic23@xxxxxxxxxx> > > Sent: Saturday, June 29, 2024 2:51 AM > > To: Tinaco, Mariel <Mariel.Tinaco@xxxxxxxxxx> > > Cc: linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > > kernel@xxxxxxxxxxxxxxx; Lars-Peter Clausen <lars@xxxxxxxxxx>; Rob > > Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>; > > Conor Dooley <conor+dt@xxxxxxxxxx>; Liam Girdwood > > <lgirdwood@xxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; Hennerich, > > Michael <Michael.Hennerich@xxxxxxxxxx>; Marcelo Schmitt > > <marcelo.schmitt1@xxxxxxxxx>; Dimitri Fedrau <dima.fedrau@xxxxxxxxx>; > > Guenter Roeck <linux@xxxxxxxxxxxx> > > Subject: Re: [PATCH 2/2] iio: dac: support the ad8460 Waveform DAC > > > > [External] > > > > On Mon, 24 Jun 2024 04:56:57 +0000 > > "Tinaco, Mariel" <Mariel.Tinaco@xxxxxxxxxx> wrote: > > > > > > -----Original Message----- > > > > From: Jonathan Cameron <jic23@xxxxxxxxxx> > > > > Sent: Sunday, May 12, 2024 12:44 AM > > > > To: Tinaco, Mariel <Mariel.Tinaco@xxxxxxxxxx> > > > > Cc: linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > > > > kernel@xxxxxxxxxxxxxxx; Lars-Peter Clausen <lars@xxxxxxxxxx>; Rob > > > > Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski > > > > <krzk+dt@xxxxxxxxxx>; Conor Dooley <conor+dt@xxxxxxxxxx>; Liam > > > > Girdwood <lgirdwood@xxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; > > > > Hennerich, Michael <Michael.Hennerich@xxxxxxxxxx>; Marcelo Schmitt > > > > <marcelo.schmitt1@xxxxxxxxx>; Dimitri Fedrau > > > > <dima.fedrau@xxxxxxxxx>; Guenter Roeck <linux@xxxxxxxxxxxx> > > > > Subject: Re: [PATCH 2/2] iio: dac: support the ad8460 Waveform DAC > > > > > > > > [External] > > > > > > > > On Fri, 10 May 2024 14:40:53 +0800 Mariel Tinaco > > > > <Mariel.Tinaco@xxxxxxxxxx> wrote: > > > > > > > > > The AD8460 is a “bits in, power out” high voltage, high-power, > > > > > highspeed driver optimized for large output current (up to ±1 A) > > > > > and high slew rate (up to ±1800 V/μs) at high voltage (up to ±40 > > > > > V) into capacitive loads. > > > > > > > > > > A digital engine implements user-configurable features: modes > > > > > for digital input, programmable supply current, and fault > > > > > monitoring and programmable protection settings for output > > > > > current, output voltage, and junction temperature. The AD8460 > > > > > operates on high voltage dual supplies up to ±55 V and a single low > voltage supply of 5 V. > > > > > > > > > > Signed-off-by: Mariel Tinaco <Mariel.Tinaco@xxxxxxxxxx> > > > > > > > > I'd like to see some ABI docs for the debugfs interface. > > > > The device is unusual enough that a general intro document or a > > > > lot more in the series cover letter would be useful. > > > > > > > > I'm not sure what the dmaengine usage in here is doing for example? > > > > Driving the parallel bus perhaps? David was correct that the > > > > binding should reflect that part as well. I was assuming you'd > > > > only > > implemented the spi part. > > > > > > > > How to handle the pattern generator is also an interesting question. > > > > That probably wants a version of the symbol interfaces we use for > > > > PSK and similar. We did have some DDS drivers a long time back in > > > > staging but they only did a few fixed waveforms so this is > > > > breaking new > > ground. > > > > > > I also thought about how should the pattern generator be handled. IN > > > the last revision, there were two debug attributes that make up this > > > feature. Pattern depth and pattern memory. Ultimately I found a way > > > to combine these two attributes into one called "test_pattern". The > > > attribute is a string containing an array of values with a maximum > > > of > > > 16 data words, which the DAC will cycle through to generate a pattern. > > > The number of values within the string can be anywhere between 1 to > > > 16 and > > have a space in between. I also added a "test_pattern_enable" > > > debug attribute. For the ABI file, should I create one alongside > > > other "debugfs- > > *" > > > files and just mention the name of the part? e.g. "debugfs-driver-ad8460" > > > > Doing this in debugfs basically means you aren't intending it to get > > used in real usecases. So we need some sysfs ABI. > > > > That probably means a mode switch similar to the ones we have for > > devices that use an external toggle (typically for Frequency Shift > > Keying or similar or sometimes just to flip between two DC voltages). > > We need a new term though as this isn't a toggle. > > > > For the values we could map it to that interface which is something > > like > > > > out_voltage0_raw0 > > out_voltage0_raw1 > > > > etc. That avoids need for a new ABI for the values, but perhaps isn't > > that elegant if the patterns on other devices we eventually support this on get > large. > > I saw some drivers making use of "test_pattern" attribute. I think that might fit. > But I'd look into "raw0" and "raw1" as well I'm sorry about mentioning "test_pattern" again. I forgot I already mentioned it in An earlier reply > > > > > Anyone know how large these typically get? I'm being lazy and don't > > want to datasheet dive this evening! > > It only gets up to 16 values. > > > > > Jonathan
