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Author SHA1 Message Date
Marek Vasut
a115b1bd3a PCI: rcar: Add L1 link state fix into data abort hook 
When the link is in L1, hardware should return it to L0
automatically whenever a transaction targets a component on the
other end of the link (PCIe r5.0, sec 5.2).

The R-Car PCIe controller doesn't handle this transition correctly.
If the link is not in L0, an MMIO transaction targeting a downstream
device fails, and the controller reports an ARM imprecise external
abort.

Work around this by hooking the abort handler so the driver can
detect this situation and help the hardware complete the link state
transition.

When the R-Car controller receives a PM_ENTER_L1 DLLP from the
downstream component, it sets PMEL1RX bit in PMSR register, but then
the controller enters some sort of in-between state.  A subsequent
MMIO transaction will fail, resulting in the external abort.  The
abort handler detects this condition and completes the link state
transition by setting the L1IATN bit in PMCTLR and waiting for the
link state transition to complete.

Link: https://lore.kernel.org/r/20210815181650.132579-1-marek.vasut@gmail.com
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: linux-renesas-soc@vger.kernel.org
 2021-08-16 14:51:30 +01:00
Lad Prabhakar
2a6d0d63d9 PCI: rcar: Add endpoint mode support 
Add support for R-Car PCIe controller to work in endpoint mode.

Link: https://lore.kernel.org/r/1588854799-13710-8-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
 2020-05-22 12:35:32 +01:00
Lad Prabhakar
78a0d7f2f5 PCI: rcar: Move shareable code to a common file 
Move shareable code to common file pcie-rcar.c and the #defines to
pcie-rcar.h so that the common code can be reused with endpoint driver.
There are no functional changes with this patch for the host controller
driver.

Link: https://lore.kernel.org/r/1588854799-13710-3-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
 2020-05-11 11:29:47 +01:00