kernel/linux.git/include/linux/i3c/master.h, branch v7.0-rc7

i3c: master: Add i3c_master_do_daa_ext() for post-hibernation address recovery

2026-01-30T23:02:24+00:00

After system hibernation, I3C Dynamic Addresses may be reassigned at boot and no longer match the values recorded before suspend. Introduce i3c_master_do_daa_ext() to handle this situation. The restore procedure is straightforward: issue a Reset Dynamic Address Assignment (RSTDAA), then run the standard DAA sequence. The existing DAA logic already supports detecting and updating devices whose dynamic addresses differ from previously known values. Refactor the DAA path by introducing a shared helper used by both the normal i3c_master_do_daa() path and the new extended restore function, and correct the kernel-doc in the process. Export i3c_master_do_daa_ext() so that master drivers can invoke it from their PM restore callbacks. Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260123063325.8210-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni

i3c: master: Introduce optional Runtime PM support

2026-01-14T16:21:10+00:00

Master drivers currently manage Runtime PM individually, but all require runtime resume for bus operations. This can be centralized in common code. Add optional Runtime PM support to ensure the parent device is runtime resumed before bus operations and auto-suspended afterward. Notably, do not call ->bus_cleanup() if runtime resume fails. Master drivers that opt-in to core runtime PM support must take that into account. Also provide an option to allow IBIs and hot-joins while runtime suspended. Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260113072702.16268-20-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni

i3c: add sysfs entry and attribute for Device NACK Retry count

2026-01-13T17:26:47+00:00

Document sysfs attribute dev_nack_retry_cnt that controls the number of automatic retries performed by the I3C controller when a target device returns a NACK Add a `dev_nack_retry_count` sysfs attribute to allow reading and updating the device NACK retry count. A new `dev_nack_retry_count` field and an optional `set_dev_nack_retry()` callback are added to i3c_master_controller. The attribute is created only when the callback is implemented. Updates are applied under the I3C bus maintenance lock to ensure safe hardware reconfiguration. Signed-off-by: Adrian Ng Ho Yin Reviewed-by: Frank Li Link: https://patch.msgid.link/3c4b5082bde64024fc383c44bebeef89ad3c7ed3.1765529948.git.adrianhoyin.ng@altera.com Signed-off-by: Alexandre Belloni

i3c: master: cleanup callback .priv_xfers()

2025-12-12T22:59:39+00:00

Remove the .priv_xfers() callback from the framework after all master controller drivers have switched to use the new .i3c_xfers() callback. Signed-off-by: Frank Li Tested-by: Tommaso Merciai Link: https://patch.msgid.link/20251203-i3c_xfer_cleanup_master-v2-2-7dd94d04ee2d@nxp.com Signed-off-by: Alexandre Belloni

i3c: document i3c_xfers

2025-12-02T16:16:30+00:00

i3c_xfers was left undocumented, document it. Reported-by: Stephen Rothwell Link: https://patch.msgid.link/20251202153804.2640623-2-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni

i3c: Add HDR API support

2025-11-28T23:39:07+00:00

Rename struct i3c_priv_xfer to struct i3c_xfer, since private xfer in the I3C spec refers only to SDR transfers. Ref: i3c spec ver1.2, section 3, Technical Overview. i3c_xfer will be used for both SDR and HDR. Rename enum i3c_hdr_mode to i3c_xfer_mode. Previous definition need match CCC GET_CAP1 bit position. Use 31 as SDR transfer mode. Add i3c_device_do_xfers() with an xfer mode argument, while keeping i3c_device_do_priv_xfers() as a wrapper that calls i3c_device_do_xfers() with I3C_SDR for backward compatibility. Introduce a 'cmd' field in struct i3c_xfer as an anonymous union with 'rnw', since HDR mode uses read/write commands instead of the SDR address bit. Add .i3c_xfers() callback for master controllers. If not implemented, fall back to SDR with .priv_xfers(). The .priv_xfers() API can be removed once all controllers switch to .i3c_xfers(). Add 'mode_mask' bitmask to advertise controller capability. Signed-off-by: Frank Li Link: https://patch.msgid.link/20251106-i3c_ddr-v11-1-33a6a66ed095@nxp.com Signed-off-by: Alexandre Belloni

i3c: master: Add helpers for DMA mapping and bounce buffer handling

2025-09-16T15:06:42+00:00

Some I3C controllers such as MIPI I3C HCI may pad the last DWORD (32-bit) with stale data from the RX FIFO in DMA transfers if the receive length is not DWORD aligned and when the device DMA is IOMMU mapped. In such a case, a properly sized bounce buffer is required in order to avoid possible data corruption. In a review discussion, proposal was to have a common helpers in I3C core for DMA mapping and bounce buffer handling. Drivers may use the helper i3c_master_dma_map_single() to map a buffer for a DMA transfer. It internally allocates a bounce buffer if buffer is not DMA'able or when the driver requires it for a transfer. Helper i3c_master_dma_unmap_single() does the needed cleanups and data copying from the bounce buffer. Signed-off-by: Jarkko Nikula Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20250822105630.2820009-2-jarkko.nikula@linux.intel.com Signed-off-by: Alexandre Belloni

i3c: Add more parameters for controllers to the header

2025-07-30T23:33:20+00:00

Add standard timing value definition from specification. Signed-off-by: Wolfram Sang Tested-by: Tommaso Merciai Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20250724094146.6443-3-wsa+renesas@sang-engineering.com Signed-off-by: Alexandre Belloni

i3c: Standardize defines for specification parameters

2025-07-30T23:33:20+00:00

Align existing defines to follow the consistent pattern: I3C_BUS___. Prepare the codebase for adding new parameters and help avoid duplication. Signed-off-by: Wolfram Sang Tested-by: Tommaso Merciai Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20250724094146.6443-2-wsa+renesas@sang-engineering.com Signed-off-by: Alexandre Belloni

i3c: Remove the const qualifier from i2c_msg pointer in i2c_xfers API

2025-02-20T21:54:28+00:00

The change is necessary to enable the use of the `i2c_get_dma_safe_msg_buf()` API, which requires a non-const `struct i2c_msg *` to operate. The `i2c_get_dma_safe_msg_buf()` function ensures safe handling of I2C messages when using DMA, making it essential for scenarios where DMA transfers are involved. By removing the `const` qualifier, this patch allows drivers to prepare and manage DMA-safe buffers directly. Signed-off-by: Billy Tsai Reviewed-by: Frank Li Reviewed-by: Wolfram Sang Acked-by: Mukesh Kumar Savaliya Link: https://lore.kernel.org/r/20250204091702.4014466-1-billy_tsai@aspeedtech.com Signed-off-by: Alexandre Belloni