diff options
author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2019-10-11 18:27:50 +0200 |
---|---|---|
committer | Sascha Hauer <s.hauer@pengutronix.de> | 2019-10-14 15:18:16 +0200 |
commit | efd517c35f122bb08ebc1fc29e741a5211553acc (patch) | |
tree | c74ed2f4b48b7397b65d6a3edafc87449da5a3b2 /drivers/mfd/Kconfig | |
parent | 6fa1b91f6e7596472c5197f6960e3e14b9c30795 (diff) | |
download | barebox-efd517c35f122bb08ebc1fc29e741a5211553acc.tar.gz barebox-efd517c35f122bb08ebc1fc29e741a5211553acc.tar.xz |
mfd: add basic Super I/O chip helpers
Super I/O chips are ICs common to x86 that are used for interfacing
to low-bandwidth peripherals. They often contain serial ports, watchdog
timers and hardware monitoring units.
They are usually addressable via one of two I/O port pairs, either
0x2e-0x2f or 0x4e-0x4f, but they don't typically respond to reads from
their range unless a device-specific 'password' has been poked in.
After this is done, they are read and written in the same manner however.
On Linux, these devices aren't subject to any device/driver model.
Each driver for some function (e.g. watchdog or GPIO) duplicates the
device probe in the module_init and board-specific configuration
is handled via module parameters.
Lets do it a bit fancier in barebox and add a helper to register chips
and a regmap for the control and configuration registers as well as a
helper to register child devices for each function contained within the
Super I/O chip.
Board-specific configuration, e.g. which pin to use as a watchdog reset,
can then be realized using barebox device-specific parameters.
The regmap will be more of a debugging aid, however.
For ease of porting from Linux, it's expected that access to the
I/O ports won't happen via the regmap. For this reason, the new
<superio.h> header offers functions to read/write these chips' registers
as well.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/mfd/Kconfig')
-rw-r--r-- | drivers/mfd/Kconfig | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 7d924cfca1..bd6f14a59f 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -67,4 +67,7 @@ config MFD_STPMIC1 help Select this to support communication with the STPMIC1. +config MFD_SUPERIO + bool + endmenu |