On Sun, Feb 16, 2020 at 7:30 PM Noralf Trønnes <noralf@xxxxxxxxxxx> wrote: > > Hi, > > A while back I had the idea to turn a Raspberry Pi Zero into a $5 > USB to HDMI/SDTV/DSI/DPI display adapter. > > Thinking about how to represent the display to the driver I realised > that hardware use registers as API. And Linux does have a generic > register abstraction: regmap. Furthermore this means that if I can do a > regmap over USB implementation, it will be easy to do other functions > like gpio, adc and others. After a few iterations trying to understand > the USB subsystem and satisfying driver requirements, I now have > something that looks promising. > > I'm sending out an early version hoping to get feedback especially on > the core parts that handles regmap and interrupts. > > Overview: > > USB Host : USB Device > : > -------------- : ------------------ > ---------- | mfd: mud | : | f_mud | ---------- > | Driver | -------------- : | | | Driver | > ---------- | regmap-usb | : | (mud_regmap) | ---------- > -------------- : ------------------ > > > I've attached 2 drivers: > - gpio/pinctrl: is more or less finished > - display: needs a lot more work Can regmap-usb be used for drivers/mfd/dln2.c for example? -- With Best Regards, Andy Shevchenko
