This is a continuation of the previous series "Export the target RPM fan control by ChromeOS EC under hwmon" (https://lore.kernel.org/lkml/20250313-extend_ec_hwmon_fan-v1-0-5c566776f2c4@xxxxxxxxxxxx/T/#t). There is a change from controlling the target fan RPM value to control the PWM value. We anticipate to involve fans connected to EC as thermal cooling devices, so we can utilize the thermal framework to have further thermal control strategies. This series updates the required EC controls definitions, implements the mechanism for controlling fan PWM values, and registers these fans under thermal framework as cooling devices. Adapting comments from the previous series, the driver probes the host command capability at beginning to see whether a fan is controllable: - if command `EC_CMD_PWM_GET_FAN_DUTY` is supported (v0, this is a new command). - if command `EC_CMD_THERMAL_AUTO_FAN_CTRL` v2 is supported. - if command `EC_CMD_PWM_SET_FAN_DUTY` v1 is supported. This combination is selected as this is the minimum requirement for a fan to be fully controllable under hwmon framework. The driver supports changing the fan control mode, and allows to change the fan PWM value only if the fan is in manual control mode. The power management hook is implemented as well for keeping the fan control settings, as EC will automatically restore the control method to auto when device is suspended. Change-Id: I4e2fdc8c4bc50778c0d04cfbefeaab7088d3181e Signed-off-by: Sung-Chi Li <lschyi@xxxxxxxxxx> --- Changes in v2: - Change column from 80 to 100 and fix styles. - Directly store driver data into platform dev with platform_set_drvdata. - Unify the PWM unit (from 0 ~ 255) between hwmon and thermal cooling devices. - Only fetch the fan control mode and PWM value when suspending rather than caching values when writing. The suspend hook is thus added. - Link to v1: https://lore.kernel.org/r/20250429-cros_ec_fan-v1-0-a8d9e3efbb1a@xxxxxxxxxxxx --- Sung-Chi Li (3): platform/chrome: update pwm fan control host commands hwmon: (cros_ec) add PWM control over fans hwmon: (cros_ec) register fans into thermal framework cooling devices Documentation/hwmon/cros_ec_hwmon.rst | 7 +- drivers/hwmon/cros_ec_hwmon.c | 267 +++++++++++++++++++++++++ include/linux/platform_data/cros_ec_commands.h | 29 ++- 3 files changed, 301 insertions(+), 2 deletions(-) --- base-commit: 33035b665157558254b3c21c3f049fd728e72368 change-id: 20250429-cros_ec_fan-da3b64ac9c10 Best regards, -- Sung-Chi Li <lschyi@xxxxxxxxxxxx>
