On Fri, 20 Nov 2020 12:31:23 -0800 Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> wrote: > On Fri, Nov 20, 2020 at 11:54 AM Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: > > > > On 11/20/20 8:17 PM, Matt Ranostay wrote: > > > On Fri, Nov 20, 2020 at 5:15 AM rishi gupta <gupt21@xxxxxxxxx> wrote: > > >> On Fri, Nov 20, 2020 at 8:31 AM Matt Ranostay > > >> <matt.ranostay@xxxxxxxxxxxx> wrote: > > >>> Add support for the three 10-bit ADC channels registered via > > >>> the IIO subsystem. > > >>> > > >>> Cc: linux-input@xxxxxxxxxxxxxxx > > >>> Cc: linux-iio@xxxxxxxxxxxxxxx > > >>> CC: Rishi Gupta <gupt21@xxxxxxxxx> > > >>> Signed-off-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> > > >>> --- > > >>> drivers/hid/Kconfig | 1 + > > >>> drivers/hid/hid-mcp2221.c | 65 ++++++++++++++++++++++++++++++++++++++- > > >>> 2 files changed, 65 insertions(+), 1 deletion(-) > > >>> > > >>> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig > > >>> index 05315b434276..4795744d9979 100644 > > >>> --- a/drivers/hid/Kconfig > > >>> +++ b/drivers/hid/Kconfig > > >>> @@ -1157,6 +1157,7 @@ config HID_MCP2221 > > >>> tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support" > > >>> depends on USB_HID && I2C > > >>> depends on GPIOLIB > > >>> + depends on IIO > > >> I am wondering what will happen on systems which do not enable IIO. > > >> This driver can not be used there. > > >> Is my understanding correct? > > > Actually yeah this should be "select IIO" to avoid that issue. > > > > No, we should not have a individual driver select a framework. This will > > cause all kinds of issues with reverse dependencies. > > > > It might be worth splitting this driver into a MFD driver, then the MFD > > cells could have their own module that depend on the subsystem and if > > not enabled the functionality will not be provided. > > Would it make sense to use IS_REACHABLE(CONFIG_IIO) for the iio blocks? > > Guessing the weak reference "imply IIO" would still be bad for the > driver selecting a framework? A lesser option than going full MFD for this (which is probably the right design decision but is a big change) would be to just put the IIO stuff in a separate C file and use some build time magic. I agree with Lars though that this is probably better done as an MFD. It supports a bunch of things in entirely different subsystems afterall. Jonathan > > Thanks, > > Matt > > > > > - Lars > >
