kernel/drivers/i3c/master/mipi-i3c-hci/pio.c, branch linux-rolling-stable

i3c: mipi-i3c-hci: Consolidate spinlocks

2026-03-19T15:15:31Z

commit fa12bb903bc3ed1826e355d267fe134bde95e23c upstream. The MIPI I3C HCI driver currently uses separate spinlocks for different contexts (PIO vs. DMA rings). This split is unnecessary and complicates upcoming fixes. The driver does not support concurrent PIO and DMA operation, and it only supports a single DMA ring, so a single lock is sufficient for all paths. Introduce a unified spinlock in struct i3c_hci, switch both PIO and DMA code to use it, and remove the per-context locks. No functional change is intended in this patch. Fixes: 9ad9a52cce282 ("i3c/master: introduce the mipi-i3c-hci driver") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260306072451.11131-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman

i3c: mipi-i3c-hci: Convert remaining DBG() prints to dev_dbg()

2025-09-16T15:06:42Z

Get rid of local DBG() macro and convert remaining debug prints to dev_dbg() which can be controlled without code recompile when kernel is built with dynamic debug support. Signed-off-by: Jarkko Nikula Link: https://lore.kernel.org/r/20250827103009.243771-6-jarkko.nikula@linux.intel.com Signed-off-by: Alexandre Belloni

i3c: mipi-i3c-hci: Change interrupt status prints to dev_dbg()

2025-09-16T15:06:42Z

Change interrupt status prints from local DBG() macro to dev_dbg() in order to make it easier to enable them without needing to recompile code with DEBUG defined. While doing so, spell out the status register names as they are in the specification to make it easier to differentiate between different interrupt status registers. Since dynamic debug prints can include the line number remove the "(in)" and "(out)" markers from the PIO interrupt status prints. Prefix the ring interrupt status print using "Ring %d" instead of "rh%d" to make it uniform across all other prints showing the ring number. Signed-off-by: Jarkko Nikula Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20250827103009.243771-2-jarkko.nikula@linux.intel.com Signed-off-by: Alexandre Belloni

i3c: mipi-i3c-hci: Handle interrupts according to current specifications

2024-10-31T23:06:14Z

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 9ad9a52cce28 ("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 Link: https://lore.kernel.org/r/20240920144432.62370-3-jarkko.nikula@linux.intel.com Signed-off-by: Alexandre Belloni

i3c/master: introduce the mipi-i3c-hci driver

2020-11-23T09:22:18Z

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 Signed-off-by: Boris Brezillon Link: https://lore.kernel.org/linux-i3c/20201111220510.3622216-3-nico@fluxnic.net