[PATCH v3 12/23] dt-bindings: ata: ahci: Add platform capability properties

Serge Semin
2022-05-11T23:19:03Z

In case if the platform doesn't have BIOS or a comprehensive firmware
installed then the HBA capability flags will be left uninitialized. As a
good alternative we can define a set AHCI DT-node properties to describe
all of HW-init capabilities flags. Luckily there aren't too many of them.
SSS - Staggered Spin-up support and MPS - Mechanical Presence Switch
support determine the corresponding feature availability for whole HBA by
means of the "hba-sss" and "hba-smps" properties. Each port can have the
"hba-{hpcp,mpsp,cpd,esp,fbscp}" defined indicatating that the port
supports the next functionality: HPCP - HotPlug capable port, MPSP -
Mechanical Presence Switch attached to a port, CPD - Cold Plug detection,
ESP - External SATA Port (eSATA), FBSCP - FIS-based switching capable
port.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>

---

Alternatively we could define them as a bitfield, but having a set of
boolean properties seemed a better idea since in that case we can
implement a simple inter-dependency rules for them, which can't be done
should we take the bitfields path.
---
.../devicetree/bindings/ata/ahci-common.yaml | 66 +++++++++++++++++++
.../bindings/ata/ahci-platform.yaml | 11 ++++
2 files changed, 77 insertions(+)

diff --git a/Documentation/devicetree/bindings/ata/ahci-common.yaml b/Documentation/devicetree/bindings/ata/ahci-common.yaml
index a7d1a8353de3..a29edfbb25db 100644
--- a/Documentation/devicetree/bindings/ata/ahci-common.yaml
+++ b/Documentation/devicetree/bindings/ata/ahci-common.yaml
@@ -75,6 +75,19 @@ properties:
phy-names:
const: sata-phy

+ hba-sss:
+ type: boolean
+ description:
+ Staggered Spin-up Support. Indicates whether the HBA supports the
+ staggered spin-up on its ports, for use in balancing power spikes.
+
+ hba-smps:
+ type: boolean
+ description:
+ Mechanical Presence Switch Support. Indicates whether the HBA supports
+ mechanical presence switches on its ports for use in hot plug
+ operations.
+
ports-implemented:
$ref: '/schemas/types.yaml#/definitions/uint32'
description:
@@ -97,6 +110,40 @@ patternProperties:
minimum: 0
maximum: 31

+ hba-hpcp:
+ type: boolean
+ description:
+ Hot Plug Capable Port. Indicates that this port’s signal and power
+ connectors are externally accessible via a joint signal and power
+ connector for blindmate device hot plug. It is mutually exclusive
+ with the ESP feature.
+
+ hba-mpsp:
+ type: boolean
+ description:
+ Mechanical Presence Switch Attached to Port. Indicates whether
+ the platform an mechanical presence switch attached to this
+ port.
+
+ hba-cpd:
+ type: boolean
+ description:
+ Cold Presence Detection. Indicates whether the platform supports
+ cold presence detection on this port.
+
+ hba-esp:
+ type: boolean
+ description:
+ External SATA Port. Indicates that this port’s signal connector
+ is externally accessible on a signal only connector (e.g. eSATA
+ connector).
+
+ hba-fbscp:
+ type: boolean
+ description:
+ FIS-based Switching Capable Port. Indicates whether this port
+ supports Port Multiplier FIS-based switching.
+
phys:
description: Individual AHCI SATA port PHY
maxItems: 1
@@ -111,6 +158,25 @@ patternProperties:
required:
- reg

+ # eSATA can't be enabled together with the HotPlug capability
+ oneOf:
+ - required:
+ - hba-hpcp
+ - required:
+ - hba-esp
+ - not:
+ anyOf:
+ - required:
+ - hba-hpcp
+ - required:
+ - hba-esp
+
+ # HotPlug capability must be enabled together with Cold Plug
+ # Detection and Mechanical Presence Switching.
+ dependencies:
+ hba-cpd: ["hba-hpcp"]
+ hba-mpsp: ["hba-hpcp"]
+
additionalProperties: true

required:
diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.yaml b/Documentation/devicetree/bindings/ata/ahci-platform.yaml
index 76075d3c8987..6cad7e86f3bb 100644
--- a/Documentation/devicetree/bindings/ata/ahci-platform.yaml
+++ b/Documentation/devicetree/bindings/ata/ahci-platform.yaml
@@ -117,14 +117,25 @@ examples:
#address-cells = <1>;
#size-cells = <0>;

+ hba-smps;
+
sata0: sata-port@0 {
reg = <0>;
+
+ hba-fbscp;
+ hba-esp;
+
phys = <&sata_phy 0>;
target-supply = <&reg_sata0>;
};

sata1: sata-port@1 {
reg = <1>;
+
+ hba-fbscp;
+ hba-hpcp;
+ hba-mpsp;
+
phys = <&sata_phy 1>;
target-supply = <&reg_sata1>;
};
--
2.35.1