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dongjiuzhu1 da6a682abc drivers/i2c: add ioexpander-based lower-half implementation for I2C bit-bang
This commit adds a new lower-half driver implementation for I2C bit-bang
that uses IO expander pins as the GPIO backend, enabling I2C bit-bang
functionality on systems where direct GPIO access is not available or
when I2C needs to be implemented using IO expander pins.

Background:
The existing I2C bit-bang driver (i2c_bitbang.c) provides a generic
upper-half implementation that requires a platform-specific lower-half
to control the SDA and SCL GPIO lines. Previously, each platform had to
implement its own lower-half using direct GPIO access.

Usage Example:
FAR struct ioexpander_dev_s *ioe = /* get IO expander */;
FAR struct i2c_master_s *i2c;

/* Initialize I2C bit-bang using IO expander pins 10 (SCL) and 11 (SDA) */
i2c = i2c_bitbang_ioexpander_initialize(ioe, 10, 11, 0);
if (i2c)
  {
    /* Use i2c master device normally */
  }

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
2026-01-01 17:08:47 +08:00
.github mtd/at25ee: Use eeprom/spi_xx25xx internally 2025-12-17 19:03:54 +01:00
arch risc-v/litex: Add 64-bit S-mode vexiiriscv support for litex. 2025-12-30 10:18:57 -03:00
audio fs/file: unify prefix about file_xxx api, like file_open, file_ioctl 2025-06-12 18:12:42 +08:00
binfmt sched:use tcb_s inside of task_tcb_s , remove all cast 2025-12-22 17:55:45 +08:00
boards boards/xtensa/esp32s3: Add ostest defconfig 2026-01-01 17:03:20 +08:00
cmake cmake: Improve nuttx_generate_kconfig() 2025-12-02 02:45:36 +08:00
crypto LICENSE: update NuttX-PublicDomain SPDX identifier 2025-12-26 19:46:12 +08:00
Documentation Docs/platforms/esp32s3: Add ostest docs 2026-01-01 17:03:20 +08:00
drivers drivers/i2c: add ioexpander-based lower-half implementation for I2C bit-bang 2026-01-01 17:08:47 +08:00
dummy build: add initial cmake build system 2023-07-08 13:50:48 +08:00
fs fs/file: add reference count protection for stack-allocated file structures 2026-01-01 17:06:17 +08:00
graphics sched/sleep: replace all Signal-based sleep implement to Scheduled sleep 2025-10-17 14:05:02 +08:00
include drivers/i2c: add ioexpander-based lower-half implementation for I2C bit-bang 2026-01-01 17:08:47 +08:00
libs libc/syslograwstream: Use memrchr to locate the newline character 2026-01-01 17:03:50 +08:00
mm mm/iob:support iob queue concat to another iob queue 2026-01-01 17:03:29 +08:00
net net_sockif.c: add ip level s|getsockopt support in SOCK_CTRL 2026-01-01 17:04:03 +08:00
openamp openamp: update openamp and libmetal to last release version 2025-12-31 02:36:29 +08:00
pass1 Revert "build depend:Revert Make.dep intermediate ddc file" 2024-09-15 19:29:47 +08:00
sched sched/clock: [bugfix] should return -EINVAL when clock_id is invalid 2025-12-30 10:22:09 -03:00
syscall syscall/adjtime: fix minior issue about adjtime and add clock_adjtime to syscall 2025-12-30 10:22:09 -03:00
tools toos/scipts: add script to find symbol caller 2025-12-31 08:47:23 -03:00
video Revert "build depend:Revert Make.dep intermediate ddc file" 2024-09-15 19:29:47 +08:00
wireless net/wireless: fix compile warning 2025-12-25 18:05:33 +08:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines net/icmpv6: replace net_lock with conn_lock and conn_lock_dev 2025-12-29 09:42:18 +08:00
.codespellrc codespellrc: add ist to ignorelist 2025-10-14 17:42:01 +08:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore gitignore: add more vim swap files 2025-06-18 15:44:51 -04:00
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.pre-commit-config.yaml pre-commit: enable codespell checks 2025-05-05 12:34:39 +08:00
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AUTHORS AUTHORS: add Michal Lenc 2025-12-03 08:46:33 -03:00
CMakeLists.txt cmake: Add support for ccache. 2025-12-05 11:46:30 +01:00
CONTRIBUTING.md style: fix spelling in code comments and strings 2025-05-23 10:48:41 +08:00
INVIOLABLES.md
Kconfig drivers/timers/ptp: support ptp clock driver model 2025-12-30 10:22:09 -03:00
LICENSE style: fix spelling in code comments and strings 2025-05-23 10:48:41 +08:00
Makefile tools: migrate to SPDX identifier 2024-09-10 23:11:11 +08:00
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README.md Gathering community recommendations 2023-10-28 13:55:56 +08:00
ReleaseNotes Documentation: move ReleaseNotes 2023-09-26 20:41:00 +08:00

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Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).

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