Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   Frank Wunderlich <linux@fw-web.de>
To:     linux-rockchip@lists.infradead.org
Cc:     Frank Wunderlich <frank-w@public-files.de>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Johan Jonker <jbx6244@gmail.com>,
        Peter Geis <pgwipeout@gmail.com>,
        Michael Riesch <michael.riesch@wolfvision.net>,
        linux-pci@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-phy@lists.infradead.org
Subject: [RFC/RFT v2 09/11] dt-bindings: pci: add lane-map to rockchip PCIe binding
Date:   Tue, 26 Apr 2022 15:21:37 +0200
Message-Id: <20220426132139.26761-10-linux@fw-web.de>
In-Reply-To: <20220426132139.26761-1-linux@fw-web.de>
References: <20220426132139.26761-1-linux@fw-web.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Frank Wunderlich <frank-w@public-files.de>

Create new property for (rockchip) PCIe controller binding to
define lane mapping.

Rockchip driver uses this for bifurcation (true/false) based
on lanes should be splitted across controllers or not.

On rk3568 there are 2 PCIe Controllers which share 2 PCIe lanes.

pcie3x1: pcie@fe270000 //lane1 when using 1+1
pcie3x2: pcie@fe280000 //lane0 when using 1+1

This ends up in one Controller (pcie3x1) uses lane-map = <0 1>; and
the other lane-map = <1 0>; (pcie3x2)

This means there are 2 lanes (count of numbers), one (by position)
is mapped to the first controller, the other one is used on the other
controller.

In rockchip PCIe driver the lane-map is simply converted to the
bifurcation bool instead of direct mapping a specific lane to a
controller.

There is not yet any slot mapping below one controller.
But for binding this may be possible like:

lane-map = <1 2 3 3 4 4 4 4>;
            | | | ...
        lane0 | |
          lane1 |
            lane2

on a 8-lane phy.

This can map lane0 to port1 (number used at this position),
lane1 to port2, lanes 2+3 to port 3 and lanes 4,5,6,7 to port 4.

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
---
v2:
- new patch
---
 Documentation/devicetree/bindings/pci/rockchip-dw-pcie.yaml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/rockchip-dw-pcie.yaml b/Documentation/devicetree/bindings/pci/rockchip-dw-pcie.yaml
index a992970e8b85..998b20b3a9dc 100644
--- a/Documentation/devicetree/bindings/pci/rockchip-dw-pcie.yaml
+++ b/Documentation/devicetree/bindings/pci/rockchip-dw-pcie.yaml
@@ -52,6 +52,8 @@ properties:
       - const: pclk
       - const: aux
 
+  lane-map: true
+
   msi-map: true
 
   num-lanes: true
@@ -74,8 +76,6 @@ properties:
   reset-names:
     const: pipe
 
-  bifurcation: true
-
   vpcie3v3-supply: true
 
 required:
@@ -115,6 +115,7 @@ examples:
                           "aclk_dbi", "pclk",
                           "aux";
             device_type = "pci";
+            lane-map = <0 1>;
             linux,pci-domain = <2>;
             max-link-speed = <2>;
             msi-map = <0x2000 &its 0x2000 0x1000>;
-- 
2.25.1