PCI: rcar-gen4: Configure AXIINTC if iMSI-RX is not used

When MSI is enabled but the DWC built-in iMSI-RX is not used, MSI must
be handled via the GIC ITS. Configure all controller MSI registers
accordingly.

Set or clear the MSICAP0 MSIE bit and the PCIEINTSTS0EN MSI_CTRL_INT
bit based on the MSI enable state. Set both bits when MSI is enabled.
Clear both bits when MSI is disabled.

When MSI is disabled, or when MSI is enabled together with iMSI-RX,
clear AXIINTCADDR and AXIINTCCONT to disable any pass through of MSI
TLPs onto the AXI bus and further into the GIC ITS translation
registers.

When MSI is enabled and iMSI-RX is not used, program AXIINTCADDR with
the target address of the GIC ITS translation register, and program
AXIINTCCONT to enable MSI TLP pass through onto the AXI bus and into
the GIC ITS. This configuration allows the GIC ITS to handle MSI
instead of the integrated iMSI-RX.

The driver includes linux/irqchip/arm-gic-v3.h which pulls in headers
which are available only on ARM and ARM64, on other architectures the
headers are not present and the driver fails to build. This driver is
used only on ARM64 hardware, so isolate its build only to ARM64 to avoid
build failures on other architectures.

Co-developed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
[mani: commit log and squashed the Kconfig fix:
       https://patch.msgid.link/20260714131957.38067-1-marek.vasut+renesas@mailbox.org]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260707203743.88299-3-marek.vasut+renesas@mailbox.org

0 files changed, 0 insertions, 0 deletions