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[0/3] i2c: qcom-geni: Add I2C bus recovery support

Message ID 20260826-i2c_bus_recovery-v1-0-203f0ec76f84@oss.qualcomm.com
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Series i2c: qcom-geni: Add I2C bus recovery support | expand

Message

Aniket Randive Aug. 26, 2026, 9:51 a.m. UTC 
An I2C target that gets interrupted during a transaction can hold SDA low,
leaving the bus stuck and preventing further transfers.

This series adds bus recovery support to the Qualcomm GENI I2C driver using
the hardware native I2C_BUS_CLEAR and I2C_STOP_ON_BUS M_CMD opcodes. These
commands generate up to nine SCL pulses, which is the standard I2C bus
recovery sequence, and then issue a STOP condition to release the bus
without requiring GPIO based recovery.

Recovery is triggered automatically from geni_i2c_xfer() when a transfer
fails and the SE_GENI_IOS register indicates that SDA remains low. The
recovery callback is also registered through i2c_bus_recovery_info, allowing
recovery to be initiated through the I2C core i2c_recover_bus() API.

The patches are organized as follows:

  [1/3] dmaengine: qcom: gpi: Add I2C_BUS_CLEAR and I2C_STOP_ON_BUS opcodes
  [2/3] i2c: qcom-geni: Add bus recovery support for FIFO mode
  [3/3] i2c: qcom-geni: Add bus recovery support for GPI DMA mode

Signed-off-by: Aniket Randive <aniket.randive@oss.qualcomm.com>
---
Aniket Randive (3):
      dmaengine: qcom: gpi: Add I2C bus recovery opcode support
      i2c: qcom-geni: Add bus recovery support for FIFO mode
      i2c: qcom-geni: Add bus recovery support for GPI DMA mode

 drivers/dma/qcom/gpi.c             |  30 ++++++
 drivers/i2c/busses/i2c-qcom-geni.c | 185 ++++++++++++++++++++++++++++++++++++-
 include/linux/dma/qcom-gpi-dma.h   |   2 +
 3 files changed, 215 insertions(+), 2 deletions(-)
---
base-commit: a8406e6c0b793ce0788019683837c40855b55995
change-id: 20260706-i2c_bus_recovery-8f0c20283d99

Best regards,
--  
Aniket Randive <aniket.randive@oss.qualcomm.com>