From: "Théo Lebrun" <theo.lebrun@bootlin.com>
To: Linus Walleij <linus.walleij@linaro.org>,
Andi Shyti <andi.shyti@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Conor Dooley <conor+dt@kernel.org>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mips@vger.kernel.org,
"Gregory Clement" <gregory.clement@bootlin.com>,
"Vladimir Kondratiev" <vladimir.kondratiev@mobileye.com>,
"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
"Tawfik Bayouk" <tawfik.bayouk@mobileye.com>,
"Théo Lebrun" <theo.lebrun@bootlin.com>,
"Jean Delvare" <jdelvare@suse.com>,
"Guenter Roeck" <linux@roeck-us.net>,
linux-hwmon@vger.kernel.org
Subject: [PATCH 00/13] Add Mobileye EyeQ5 support to the Nomadik I2C controller & use hrtimers for timeouts
Date: Thu, 15 Feb 2024 17:52:07 +0100 [thread overview]
Message-ID: <20240215-mbly-i2c-v1-0-19a336e91dca@bootlin.com> (raw)
Hi,
This series adds two tangent features to the Nomadik I2C controller:
- Add a new compatible to support Mobileye EyeQ5 which uses the same IP
block as Nomadik.
It has two quirks to be handled:
- The memory bus only supports 32-bit accesses. A writeb() is used
which we avoid.
- We must write a value into a shared register region (OLB, "Other
Logic Block") depending on the I2C bus speed.
- Allow xfer timeouts below one jiffy by using a workqueue and hrtimers
instead of a completion.
The situation to be addressed is:
- Many devices on the same I2C bus.
- One xfer to each device is sent at regular interval.
- One device gets stuck and does not answer.
- With long timeouts, following devices won't get their message. A
shorter timeout ensures we can still talk to the following
devices.
This clashes a bit with the current i2c_adapter timeout field that
stores a jiffies amount. We cannot rely on it and therefore we take
a value from devicetree as a µs value. If the timeout is less than a
jiffy duration, we switch from standard jiffies timeout to
hrtimers.
There is one patch targeting a hwmon dt-bindings file:
Documentation/devicetree/bindings/hwmon/lm75.yaml. The rest is touching
the I2C bus driver, its bindings and platform devicetrees.
About dependencies:
- The series is based upon v6.8-rc4.
- For testing on EyeQ5 hardware and devicetree patches, we need the
base platform series from Grégory [0].
- The last commit (adding DT phandles for resets), we need the syscon
series [1] that provides the reset controller node.
I think there are discussions to be had about:
- The handling of timeouts. Having a non-jiffy value is not driver
specific. Should this change be done at the subsystem layer? The
subsystem could even fetch the value from devicetree and auto-fill
timeout, with a default given by the driver. Not many drivers seem
to use the i2c_adapter timeout field from my quick grepping.
- The DT prop for timeout. I've picked "timeout-usecs". Some drivers
use vendor prefixes, but this is not vendor-specific and only a
software implementation detail.
- The shape of this series. Initially it was split in two. However I
brought them together as they cannot be applied independently.
Please tell me if a better approach is to be preferred.
Those are thoughts, I'm sure people will have feedback on this.
Have a nice day,
Théo Lebrun
[0]: https://lore.kernel.org/lkml/20240205153503.574468-1-gregory.clement@bootlin.com/
[1]: https://lore.kernel.org/lkml/20240212-mbly-clk-v6-0-c46fa1f93839@bootlin.com/
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
Théo Lebrun (13):
dt-bindings: i2c: nomadik: add timeout-usecs property bindings
dt-bindings: i2c: nomadik: add mobileye,eyeq5-i2c bindings and example
dt-bindings: hwmon: lm75: add label property
i2c: nomadik: rename private struct pointers from dev to priv
i2c: nomadik: simplify IRQ masking logic
i2c: nomadik: use bitops helpers
i2c: nomadik: support short xfer timeouts using waitqueue & hrtimer
i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout
i2c: nomadik: fetch timeout-usecs property from devicetree
i2c: nomadik: support Mobileye EyeQ5 I2C controller
MIPS: mobileye: eyeq5: add 5 I2C controller nodes
MIPS: mobileye: eyeq5: add evaluation board I2C temp sensor
MIPS: mobileye: eyeq5: add resets to I2C controllers
Documentation/devicetree/bindings/hwmon/lm75.yaml | 4 +
.../devicetree/bindings/i2c/st,nomadik-i2c.yaml | 49 +-
arch/mips/boot/dts/mobileye/eyeq5-epm5.dts | 8 +
arch/mips/boot/dts/mobileye/eyeq5.dtsi | 75 +++
drivers/i2c/busses/i2c-nomadik.c | 710 ++++++++++++---------
5 files changed, 534 insertions(+), 312 deletions(-)
---
base-commit: d55aa725e32849f709b61eab3b7a50b810a71a84
change-id: 20231023-mbly-i2c-7c2fbbb1299f
Best regards,
--
Théo Lebrun <theo.lebrun@bootlin.com>
next reply other threads:[~2024-02-15 16:52 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-15 16:52 Théo Lebrun [this message]
2024-02-15 16:52 ` [PATCH 01/13] dt-bindings: i2c: nomadik: add timeout-usecs property bindings Théo Lebrun
2024-02-16 2:27 ` Rob Herring
2024-02-16 9:16 ` Théo Lebrun
2024-02-16 9:17 ` Krzysztof Kozlowski
2024-02-19 14:06 ` Linus Walleij
2024-02-19 14:29 ` Théo Lebrun
2024-02-21 16:58 ` Théo Lebrun
2024-02-21 17:43 ` Wolfram Sang
2024-02-22 17:14 ` Rob Herring
2024-02-22 19:28 ` Wolfram Sang
2024-02-23 16:34 ` Rob Herring
2024-02-26 8:41 ` Wolfram Sang
2024-02-15 16:52 ` [PATCH 02/13] dt-bindings: i2c: nomadik: add mobileye,eyeq5-i2c bindings and example Théo Lebrun
2024-02-15 19:26 ` Rob Herring
2024-02-16 2:22 ` Rob Herring
2024-02-16 10:18 ` Théo Lebrun
2024-02-16 10:33 ` Krzysztof Kozlowski
2024-02-16 10:40 ` Théo Lebrun
2024-02-17 8:25 ` Krzysztof Kozlowski
2024-02-19 13:41 ` Théo Lebrun
2024-02-20 9:49 ` Krzysztof Kozlowski
2024-02-15 16:52 ` [PATCH 03/13] dt-bindings: hwmon: lm75: add label property Théo Lebrun
2024-02-16 7:41 ` Krzysztof Kozlowski
2024-02-16 8:00 ` Krzysztof Kozlowski
2024-02-16 10:22 ` Théo Lebrun
2024-02-24 17:30 ` Guenter Roeck
2024-02-26 7:43 ` Krzysztof Kozlowski
2024-02-15 16:52 ` [PATCH 04/13] i2c: nomadik: rename private struct pointers from dev to priv Théo Lebrun
2024-02-19 14:12 ` Linus Walleij
2024-02-15 16:52 ` [PATCH 05/13] i2c: nomadik: simplify IRQ masking logic Théo Lebrun
2024-02-19 14:15 ` Linus Walleij
2024-02-15 16:52 ` [PATCH 06/13] i2c: nomadik: use bitops helpers Théo Lebrun
2024-02-19 14:16 ` Linus Walleij
2024-02-15 16:52 ` [PATCH 07/13] i2c: nomadik: support short xfer timeouts using waitqueue & hrtimer Théo Lebrun
2024-02-19 14:19 ` Linus Walleij
2024-02-19 14:31 ` Théo Lebrun
2024-02-15 16:52 ` [PATCH 08/13] i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout Théo Lebrun
2024-02-19 14:21 ` Linus Walleij
2024-02-19 14:38 ` Théo Lebrun
2024-02-19 14:53 ` Linus Walleij
2024-02-15 16:52 ` [PATCH 09/13] i2c: nomadik: fetch timeout-usecs property from devicetree Théo Lebrun
2024-02-19 14:22 ` Linus Walleij
2024-02-27 12:14 ` Wolfram Sang
2024-02-27 13:38 ` Théo Lebrun
2024-02-28 10:49 ` Wolfram Sang
2024-02-28 13:39 ` Théo Lebrun
2024-02-29 9:25 ` Wolfram Sang
2024-02-29 9:31 ` Théo Lebrun
2024-02-15 16:52 ` [PATCH 10/13] i2c: nomadik: support Mobileye EyeQ5 I2C controller Théo Lebrun
2024-02-19 14:35 ` Linus Walleij
2024-02-19 14:52 ` Théo Lebrun
2024-02-19 16:27 ` Théo Lebrun
2024-02-15 16:52 ` [PATCH 11/13] MIPS: mobileye: eyeq5: add 5 I2C controller nodes Théo Lebrun
2024-02-15 16:52 ` [PATCH 12/13] MIPS: mobileye: eyeq5: add evaluation board I2C temp sensor Théo Lebrun
2024-02-16 7:59 ` Krzysztof Kozlowski
2024-02-15 16:52 ` [PATCH 13/13] MIPS: mobileye: eyeq5: add resets to I2C controllers Théo Lebrun
2024-02-16 7:59 ` Krzysztof Kozlowski
2024-02-16 9:05 ` Théo Lebrun
2024-02-16 9:17 ` Krzysztof Kozlowski
2024-02-16 10:26 ` Théo Lebrun
2024-02-19 14:11 ` [PATCH 00/13] Add Mobileye EyeQ5 support to the Nomadik I2C controller & use hrtimers for timeouts Linus Walleij
2024-02-19 14:22 ` Théo Lebrun
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