From: Zev Weiss <zev@bewilderbeest.net>
To: linux-i2c@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
devicetree@vger.kernel.org
Cc: Zev Weiss <zev@bewilderbeest.net>,
openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Guenter Roeck <linux@roeck-us.net>, Peter Rosin <peda@axentia.se>
Subject: [PATCH v2 2/2] dt-bindings: i2c: add nxp,pca9541 release-delay-us property
Date: Mon, 31 Jan 2022 16:18:10 -0800 [thread overview]
Message-ID: <20220201001810.19516-3-zev@bewilderbeest.net> (raw)
In-Reply-To: <20220201001810.19516-1-zev@bewilderbeest.net>
This property can be used to reduce arbitration overhead on busy i2c
busses by retaining ownership for a brief period in anticipation of
another transaction in the near future.
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
---
Documentation/devicetree/bindings/i2c/nxp,pca9541.txt | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt
index 42bfc09c8918..9e8819593271 100644
--- a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt
+++ b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt
@@ -6,6 +6,14 @@ Required Properties:
- reg: The I2C address of the device.
+Optional Properties:
+
+ - release-delay-us: the number of microseconds to delay before
+ releasing the bus after a transaction. If unspecified the default
+ is zero (the bus is released immediately). Non-zero values can
+ reduce arbitration overhead for back-to-back transactions, at the
+ cost of delaying the other master's access to the bus.
+
The following required properties are defined externally:
- I2C arbitration bus node. See i2c-arb.txt in this directory.
@@ -16,6 +24,7 @@ Example:
i2c-arbitrator@74 {
compatible = "nxp,pca9541";
reg = <0x74>;
+ release-delay-us = <20000>;
i2c-arb {
#address-cells = <1>;
--
2.34.1
next prev parent reply other threads:[~2022-02-01 0:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-01 0:18 [PATCH v2 0/2] ic2: mux: pca9541: add delayed-release support Zev Weiss
2022-02-01 0:18 ` [PATCH v2 1/2] i2c: " Zev Weiss
2022-02-01 0:18 ` Zev Weiss [this message]
2022-02-09 21:47 ` [PATCH v2 2/2] dt-bindings: i2c: add nxp,pca9541 release-delay-us property Rob Herring
2022-02-28 8:43 ` [PATCH v2 0/2] ic2: mux: pca9541: add delayed-release support Zev Weiss
2022-02-28 13:57 ` Guenter Roeck
2022-02-28 17:11 ` Zev Weiss
2022-02-28 17:19 ` Wolfram Sang
2022-02-28 18:10 ` Guenter Roeck
2022-02-28 21:54 ` Peter Rosin
2022-02-28 22:38 ` Zev Weiss
2022-03-02 14:43 ` Peter Rosin
2022-03-03 0:43 ` Zev Weiss
2022-03-18 11:00 ` Wolfram Sang
2022-03-21 22:32 ` Zev Weiss
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