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* [PATCH v7 0/2] input: misc: Add an initial driver for haptics inside Qcom PMIH010x PMIC
@ 2026-08-28  9:49 Fenglin Wu
  2026-08-28  9:49 ` [PATCH v7 1/2] dt-bindings: input: Add Qualcomm SPMI PMIC haptics Fenglin Wu
  2026-08-28  9:49 ` [PATCH v7 2/2] input: misc: Add Qualcomm SPMI PMIC haptics driver Fenglin Wu
  0 siblings, 2 replies; 5+ messages in thread
From: Fenglin Wu @ 2026-08-28  9:49 UTC (permalink / raw)
  To: linux-arm-msm, Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski,
	Conor Dooley, Lee Jones, Stephen Boyd, Bjorn Andersson,
	Konrad Dybcio
  Cc: David Collins, Subbaraman Narayanamurthy, Kamal Wadhwa,
	linux-input, devicetree, linux-kernel, David Heidelberg,
	Fenglin Wu, Krzysztof Kozlowski

Qualcomm PMIH0108 PMIC has a haptics module inside and it could drive
a LRA actuator with several play modes, including: DIRECT_PLAY, FIFO,
PAT_MEM, SWR, etc. Add an initial driver to support two of the play
modes using the input force-feedback framework:

-- FF_CONSTANT effect for DIRECT_PLAY mode which drives sinusoidual
  waveforms with fixed period and amplitude, which would generate
  a constant vibration effect on the LRA actuator.

-- FF_PERIODIC effect with FF_CUSTOM for FIFO streaming mode, which
  can play an arbitrary waveform composed of a sequence of 8-bit
  samples at a configurable play rate.

Also, add the device node in the existing pmih0108 dtsi files, and enble
the haptics device for several boards by updating the vmax and
lra-period sttings according to the LRA components that mounted on each
of them.

Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
---
Changes in v7:
- In the binding change, add specific pmih0108 compatible in the parent node of
  the example for completeness. It doesn't change the schema itself so
  previous Reviewed-by is still retained.
- Remove checking "h->stop_timeline" agaist 0 value in haptics_stop_work()
  to ensure the stop when it's wrapped around to 0.
- Link to v6: https://patch.msgid.link/20260806-qcom-spmi-haptics-v6-0-19fcecd5204f@oss.qualcomm.com

Changes in v6:
 Drop patch [2/3] as it has been applied in
  https://lore.kernel.org/linux-input/178602255123.2917765.7426706813083510078.b4-ty@b4/

 Fixed Sashiko review comments:
 - Add FF_SINE waveform support since FF_RUMBLE would be converted to FF_PERIODIC
   effect with FF_SINE waveform, and it is required to be supported. Also, clamp the
   FIFO play length with replay.length, also document the limitation of supporting
   replay.delay, u.periodic.magnitude and the envelope
 - Add a separate worker to handle timeout stop, which gives a clear
   way to distinguish timeout stop requests from actual play stop requests.
 - Replace disable_delayed_work_sync() in close() to cancel_delayed_work_sync()
   as it caused an issue that the work would be disabled permanently.
 - Move haptics_enable_module(h, false) into the reset action(). Calling it
   in close() would desynchronize the runtime PM state and could cause issues
   if a play is triggered after close() and before the auto suspend timer
   expires.
 - Link to v5: https://patch.msgid.link/20260804-qcom-spmi-haptics-v5-0-77128ebbdd2d@oss.qualcomm.com

Changes in v5:
 Fixed review comments from Dmitry:
 - Change to use "err" for the "ret" which hold error code
 - Remove "haptics_queue_pending(...)" functtion and inline it into the
   caller.
 - In haptics_fifo_empty_irq() when writing FIFO chunk failed, instead of
   stop the plan immediately, just clear the FIFO threshold to mask the
   interrupt.
 - Add "lockdep_assert_held(&h->play_lock)" for the helper functions
   which require to be called when the lock is held.
 - Add "gain_work" to handle set_gain() immediately.
 - Set input device bus_type to "BUS_HOST".
 - Move the remove teardown to input device close()
 - Link to v4: https://patch.msgid.link/20260717-qcom-spmi-haptics-v4-0-b0fe0ed30849@oss.qualcomm.com

Changes in v4:
 Fixed Sashiko AI review comments in the driver:
 - In haptics_start_fifo(), remove the goto and do the clear in the error
   paths directly, also add a comment to explain that disabling the IRQ
   synchronously won't cause a deadlock.
 - When data refilling failed in IRQ handler, stop the play and disable
   the IRQ to avoid the potential IRQ storming issue
 - in play_work(), check if the effect_id in the request is the one which
   under playing before stopping the play.
 - Link to v3: https://patch.msgid.link/20260713-qcom-spmi-haptics-v3-0-c931bb7cb94f@oss.qualcomm.com

 Also, add trailers in the binding changes.

Changes in v3:

 In the binding:
 - Removed the ref for qcom,vmax-microvolt as the property with standard
   unit already has a ref in dtschema
 - Added 'qcom,pmih0108-haptics' as a device-specific compatible
 
 In the driver, fixed Sashiko AI review comments with below changes:
 - Added a list to queue and serialize all of the request, which helps to
   avoid the races between playback(), which is protected by evdev's event_lock,
   and play_work(), which is protected by play_lock.
 - Changed to use guard(mutex) or scoped_guard(mutex, ) for cleaner mutex logic
   usages, and update protection section to prevent race conditions.
 - Added runtime pm control in haptics_stop() function, use it as an unified interface
   under the guard of 'play_lock' in play_work()/erase()/remove()/suspend(),
   to ensure the runtime pm control correctness in race conditions.
 - Removed unnecessary stop play sequence in fifo_empty_irq() as the HW would
   automatically stop after the FIFO samples are played out.
 - Added a common interface haptics_clear_effect() to clear the FIFO data with gaurd
   of 'fifo_lock', and use it before upload() and in erase() to prevent race
   condition.
 - used __free() for safe memory cleanup
 - Checked play_rate against negative value when loading FF_PERIOD effect
 - Limited the custom_data length to 48K prevent potential OOM
 
 - Link to v2: https://patch.msgid.link/20260624-qcom-spmi-haptics-v2-0-b9118e60f3e3@oss.qualcomm.com

Changes in v2:

 Dropped dtsi change and I will resend them after the driver and binding changes get accepted.
 
 Updated haptics binding and addressed review comments from Krzysztof and Konrad:
 - Extended the description to clarify the 'PAT_MEM' mode (not yet supported in the driver)
   by comparing it with the 'FIFO' mode.
 - Updated the compatible string to 'qcom,spmi-haptics' to match the file name and removed
   the PMIC wildcard.
 - Simplified register names to 'cfg' and 'ptn'.
 - Corrected the unit naming for the 'qcom,vmax-microvolt' property.
 - Added an additional clarification for the 'qcom,lra-period-us' property.
 
 Updated the driver to address review comments from Konrad and Julian:
 - In haptics_write_fifo_chunk(), separated variable declaration and assignment, and added
   comments explaining the 4-byte and 1-byte FIFO writes.
 - Replaced manual 'x * n / d' calculations with mult_frac().
 - Switched to disable_irq() to prevent late IRQs after device removal.
 - Replaced property reads with device_property_read_u32().
 - Remove the 'INPUT' dependency in Kconfig
 
 Updated the driver to address feedback from Sashiko AI:
 - Guarded pm_runtime_resume()/suspend() with 'pm_ref_held' to prevent runtime PM reference leaks.
 - Replaced spinlock with a mutex to protect FIFO data during playback and avoid calling
   sleepable regmap APIs under spinlock.
 - Adjusted suspend/remove() sequence to stop playback before canceling work, and freed
   FIFO buffers to prevent potential memory leaks.
 - In FF_PERIODIC handling, allocated 'fifo_data' before assigning data to ensure its
   consistency with 'data_len'.
 - Registered the input device after enabling runtime PM.
 - Unify to use 'h->dev' pointer in probe()
 
 - Link to v1: https://patch.msgid.link/20260616-qcom-spmi-haptics-v1-0-d24e422de6b4@oss.qualcomm.com

---
Fenglin Wu (2):
      dt-bindings: input: Add Qualcomm SPMI PMIC haptics
      input: misc: Add Qualcomm SPMI PMIC haptics driver

 .../bindings/input/qcom,spmi-haptics.yaml          |  139 +++
 drivers/input/misc/Kconfig                         |   11 +
 drivers/input/misc/Makefile                        |    1 +
 drivers/input/misc/qcom-spmi-haptics.c             | 1251 ++++++++++++++++++++
 4 files changed, 1402 insertions(+)
---
base-commit: 66725039f7090afe14c31bd259e2059a68f04023
change-id: 20260616-qcom-spmi-haptics-3cc97e7b232e

Best regards,
--  
Fenglin Wu <fenglin.wu@oss.qualcomm.com>


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2026-08-28 12:12 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2026-08-28  9:49 [PATCH v7 0/2] input: misc: Add an initial driver for haptics inside Qcom PMIH010x PMIC Fenglin Wu
2026-08-28  9:49 ` [PATCH v7 1/2] dt-bindings: input: Add Qualcomm SPMI PMIC haptics Fenglin Wu
2026-08-28  9:59   ` sashiko-bot
2026-08-28  9:49 ` [PATCH v7 2/2] input: misc: Add Qualcomm SPMI PMIC haptics driver Fenglin Wu
2026-08-28 12:12   ` David Heidelberg

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