linux-kernel - [PATCH v3 0/2] i2c: improve bus recovery for single-ended GPIOs

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Message-ID: <20260201111812.18945-1-jie.i.li@nokia.com>
Date: Sun,  1 Feb 2026 12:18:10 +0100
From: Jie Li <lj29312931@...il.com>
To: wsa@...nel.org,
	linusw@...nel.org
Cc: linux-i2c@...r.kernel.org,
	linux-gpio@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Jie Li <jie.i.li@...ia.com>
Subject: [PATCH v3 0/2] i2c: improve bus recovery for single-ended GPIOs

Greetings,

Apologies for the delay in responding.

Thank you very much for your review and the specific guidance regarding 
the return types. I really appreciate your patience and time spent 
guiding me through my first contribution to the kernel.

This series (v3) updates the helper function to use the 'bool' type as 
suggested and includes the Reviewed-by tags.

This series addresses a limitation in the I2C bus recovery mechanism where 
certain open-drain GPIOs are incorrectly identified as input-only, 
preventing the recovery logic from functioning.

Following the suggestion from Linus Walleij, this version drops the 
previously proposed "force-set-sda" DT property. Instead, it 
introduces a generic helper in the GPIO subsystem to identify 
single-ended configurations. This allows the I2C core to reliably 
enable recovery for open-drain lines regardless of the 
instantaneous hardware direction reporting.

Changes in v3:
- Patch 1:
  - Changed return type of gpiod_is_single_ended() from int to bool.
  - Updated return values from 0/1 to false/true.
  - Added Reviewed-by: Linus Walleij.
- Patch 2:
  - Added Reviewed-by: Linus Walleij.

Changes in v2:
- Replaced DT-based "force-set-sda" with a gpiolib helper.
- Added gpiod_is_single_ended() to drivers/gpio/gpiolib.c.
- Updated i2c-core-base.c to use the new helper.

Jie Li (2):
  gpiolib: add gpiod_is_single_ended() helper
  i2c: core: support recovery for single-ended GPIOs

 drivers/gpio/gpiolib.c        | 22 ++++++++++++++++++++++
 drivers/i2c/i2c-core-base.c   |  3 ++-
 include/linux/gpio/consumer.h |  5 +++++
 3 files changed, 29 insertions(+), 1 deletion(-)

-- 
2.43.0