Current MIPI I3C HCI specification versions pre-1.0, 1.0. 1.1 and 1.2
don't have cascaded interrupt bits for the PIO and DMA (ring headers) in
the INTR_STATUS register as implemented currently in the code. Instead
bits 9:0 are marked as reserved with unspecified reset value.
To my understanding they were planned to be introduced in the version 2
and the original commit 9ad9a52cce ("i3c/master: introduce the
mipi-i3c-hci driver") was coding ahead according to a draft. With
remarks though.
This is causing that the DMA handler is not called until at least one
reserved bit 7:0 is set in the INTR_STATUS.
Since it looks that idea was dropped in later official versions and to
make able to handle DMA interrupts on an HW that is implemented
according to current specifications call assigned PIO or DMA IO handler
unconditionally.
While doing so remove cascaded interrupt bit definitions and the mask
argument passed to the handler functions.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20240920144432.62370-3-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This adds basic support for hardware implementing the MIPI I3C HCI
specification. This driver is currently limited by the capabilities
of the I3C subsystem, meaning things like scheduled commands,
auto-commands and NCM mode are not yet supported.
This supports version 1.0 of the MIPI I3C HCI spec, as well as the
imminent release of version 1.1. Support for draft version 2.0 of the
spec is also largely included with the caveat that future adjustments
to this code are likely as the spec is still a work in progress.
This is also lightly tested as actual hardware is still very scarce,
even for HCI v1.0. Hence the EXPERIMENTAL tag. Further contributions
to this driver are expected once vendor implementations and new I3C
devices become available.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-i3c/20201111220510.3622216-3-nico@fluxnic.net
