Re: [PATCH v7 0/5] Add driver for EC found on Qualcomm reference devices

[Akhil P Oommen]

On 3/27/2026 3:38 PM, Anvesh Jain P wrote:
> From: Anvesh Jain P <anvesh.p@xxxxxxxxxxxxxxxx>
> 
> Add Embedded controller driver support for Hamoa/Purwa/Glymur Qualcomm
> reference boards. It handles fan control, temperature sensors, access
> to EC state changes and supports reporting suspend entry/exit to the EC.

Just a question, is it possible to force fan to run at full speed
constantly? That would be helpful to keep the passive cooling minimal
and get a more consistent results while doing performance profiling.

I see that you are registering a cooling device in this series. So I
suppose we just need to update the cooling sysfs nodes.

-Akhil

> 
> ---
> Changes in v7:
>   - Fixed alphabetical ordering of MAINTAINERS entry.
>   - Link to v6: https://lore.kernel.org/r/20260325-add-driver-for-ec-v6-0-a8e888d09f0f@xxxxxxxxxxxxxxxx
> 
> Changes in v6:
>   - Add missing includes: <linux/bits.h>, <linux/device.h>
>     and <linux/err.h>.
>   - Change the thermistor_mask format specifier from %d to %x.
>   - Change loop counter to unsigned int.
>   - Replace snprintf() with scnprintf() for safer string handling.
>   - Use sizeof(name) instead of the EC_FAN_NAME_SIZE macro directly.
>   - Add missing braces.
>   - Link to v5: https://lore.kernel.org/r/20260317-add-driver-for-ec-v5-0-38d11f524856@xxxxxxxxxxxxxxxx
> 
> Changes in v5:
>   - Fix subject line and commit description, drop redundant
>     "bindings for".
>   - Rename binding file: qcom,hamoa-ec.yaml → qcom,hamoa-crd-ec.yaml
>     to match the compatible string.
>   - Update $id URI to match the new filename.
>   - Add <linux/interrupt.h> and <linux/slab.h> includes.
>   - Switch to devm_thermal_of_cooling_device_register, remove manual
>     unroll loop.
>   - Ratelimit all IRQ handler log messages.
>   - Promote unknown EC event log from dev_dbg to dev_notice.
>   - Remove redundant error message after devm_request_threaded_irq.
>   - Simplify qcom_ec_sci_evt_control, resume, and suspend using direct
>     returns.
>   - Add dev_warn + early return for zero fan count; driver stays loaded
>     for PM notifications.
>   - Fix thermistor presence bitmask documentation: 1 = present, 0 = absent.
>   - Fix snprintf format specifier to %u to suppress -Wformat-truncation.
>   - Remove unused cdev variable from qcom_ec_probe.
>   - Fix typo: "exluding" → "excluding" in register map comments.
>   - Fix capitalization: "ec" → "EC" in error messages.
>   - Link to v4: https://lore.kernel.org/r/20260313-v04-add-driver-for-ec-v4-0-ca9d0efd62aa@xxxxxxxxxxxxxxxx
> 
> Changes in v4:
>   - Fix fan count calculation to use min() instead of max() to correctly
>     cap fan_cnt at EC_MAX_FAN_CNT.
>   - Remove unnecessary mutex lock/unlock.
>   - Disable fan debug mode on ec module removal.
>   - Fix issue reported by kernel test robot.
>   - Consolidate hamoa-iot-evk specific changes into hamoa-iot-evk.dts.
>   - Add board-specific compatible strings as per review comments.
>   - Link to v3: https://lore.kernel.org/all/20260308233646.2318676-1-sibi.sankar@xxxxxxxxxxxxxxxx/
> 
> Changes in v3:
>   - Revamp the bindings and driver to support generic ec specification
>     that works across Qualcomm Hamoa/Purwa and Glymur reference devices.
>   - Add ec nodes to Hamoa/Purwa CRDs and IOT-EVKs.
>   - Add ec node to Glymur CRDs.
>   - Link to v2: https://lore.kernel.org/lkml/20241219200821.8328-1-maccraft123mc@xxxxxxxxx/
>   - Link to v1: https://lore.kernel.org/lkml/20240927185345.3680-1-maccraft123mc@xxxxxxxxx/
> 
> ---
> Maya Matuszczyk (1):
>       dt-bindings: embedded-controller: Add Qualcomm reference device EC description
> 
> Sibi Sankar (4):
>       platform: arm64: Add driver for EC found on Qualcomm reference devices
>       arm64: dts: qcom: glymur-crd: Add Embedded controller node
>       arm64: dts: qcom: x1-crd: Add Embedded controller node
>       arm64: dts: qcom: hamoa-iot-evk: Add Embedded controller node
> 
>  .../embedded-controller/qcom,hamoa-crd-ec.yaml     |  56 +++
>  MAINTAINERS                                        |   8 +
>  arch/arm64/boot/dts/qcom/glymur-crd.dts            |  22 +
>  arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts         |  16 +
>  arch/arm64/boot/dts/qcom/x1-crd.dtsi               |  16 +
>  drivers/platform/arm64/Kconfig                     |  12 +
>  drivers/platform/arm64/Makefile                    |   1 +
>  drivers/platform/arm64/qcom-hamoa-ec.c             | 451 +++++++++++++++++++++
>  8 files changed, 582 insertions(+)
> ---
> base-commit: 85964cdcad0fac9a0eb7b87a0f9d88cc074b854c
> change-id: 20260309-add-driver-for-ec-3fa478f264d9
> 
> Best regards,