We could maintain the static conversions for the !AArch64 Raspberry Pis, but
I'm not sure it's worth it -- we'll traverse the platform list exactly once
(of which there are only two for armv7), then every conversion there-after
traverses the memory map listing of which there are at-most two entries for
these boards: sdram and peripheral space.
Detecting this at runtime is necessary for the AArch64 SOC, though, because
of the distinct IO windows being otherwise not discernible just from support
compiled into the kernel. We currently select the correct window based on
/compatible in the FDT.
We also use a similar mechanism to describe the DMA restrictions- the RPi 4
can have up to 4GB of RAM while the DMA controller and mailbox mechanism can
technically, kind of, only access the lowest 1GB. See the comment in
bcm2835_vcbus.h for a fun description/clarification of this.
Differential Revision: https://reviews.freebsd.org/D22301
SDHOST is another SD controller that is present on Raspberry Pi (the
other one is SDHC and handled by bcm2835_sdhci driver). Both
controllers are capable of providing interface to SD card, actual
configuration can be set in dtb file. At the moment custom DTBs for
RPi/RPi2 have sdhost node disabled. On RPi3 sdhost is disabled in
snapshot images by applying mmc.dtbo overlay. To enalbe both devices
user has to edit config.txt on FAT partition and remove or comment
"dtoverlay=mmc" line.
When no overlay applied on RPi3 SDHOST controls SD card and SDHC
interface can be used for SDIO. mmc.dtbo overlay disables SDHOST node
and switches SD card over to SDHC. Likewise sdhost.dtbo overlay (not
currently included in snapshot image, but can be obtained from firmare
repo[1]) disabled SDHC node and switch SD card over to SDHOST.
[1] https://github.com/raspberrypi/firmware/tree/master/boot/overlays
Submitted by: Klaus P. Ohrhallinger <k@7he.at>
Differential Revision: https://reviews.freebsd.org/D14168
Technically touchscreen chip is FT5406 but all hardware
communication is performed by VideCore and only final results
are presented to ARM part through memory region shared between
VC and ARM.
evdev is used as userland interface. FT5406 supports up to
10 touchpoints, but for now driver emulates single touch device
because I do not have GUI bits to test this functionality.
Driver is not enabled in default config for RPI and RPI2
Tested with: evdev-dump, tslib
Summary:
This driver supports the following methods to trigger gathering random bits from the hardware:
1. interrupt when the FIFO is full (default) fed into the harvest queue
2. callout (when BCM2835_RNG_USE_CALLOUT is defined) every second if hz is less than 100, otherwise hz / 100, feeding the random bits into the harvest queue
If the kernel is booted with verbose enabled, the contents of the registers will be dumped after the RBG is started during the attach routine.
Author: hackagadget_gmail.com (Stephen J. Kiernan)
Test Plan: Built RPI2 kernel and booted on board. Tested the different methods to feed the harvest queue (callout, interrupt) and the interrupt driven approach seems best. However, keeping the other method for people to be able to experiment with.
Reviewed By: adrian, delphij, markm
Differential Revision: https://reviews.freebsd.org/D6888