Unlike the old design that the register setting of the TACH should based on the configure of the PWM. In ast26xx, the dependency between pwm and tach controller is eliminated and becomes a separate hardware block. One is used to provide pwm output and another is used to monitor the frequency of the input. This driver implements them by exposing two kernel subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside existing drivers for controlling elements such as fans (pwm-fan.c), beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver provides sysfs interfaces for fan. Changes since v6: Consolidate the PWM and TACH functionalities into a unified driver. Changes since v5: - pwm/tach: - Remove the utilization of common resources from the parent node. - Change the concept to 16 PWM/TACH controllers, each with one channel, instead of 1 PWM/TACH controller with 16 channels. - dt-binding: - Eliminate the usage of simple-mfd. Changes since v4: - pwm: - Fix the return type of get_status function. - tach: - read clk source once and re-use it - Remove the constants variables - Allocate tach_channel as array - Use dev->parent - dt-binding: - Fix the order of the patches - Add example and description for tach child node - Remove pwm extension property Changes since v3: - pwm: - Remove unnecessary include header - Fix warning Prefer "GPL" over "GPL v2" - tach: - Remove the paremeter min_rpm and max_rpm and return the tach value directly without any polling or delay. - Fix warning Prefer "GPL" over "GPL v2" - dt-binding: - Replace underscore in node names with dashes - Split per subsystem Changes since v2: - pwm: - Use devm_* api to simplify the error cleanup - Fix the multi-line alignment problem - tach: - Add tach-aspeed-ast2600 to index.rst - Fix the multi-line alignment problem - Remove the tach enable/disable when read the rpm - Fix some coding format issue Changes since v1: - tach: - Add the document tach-aspeed-ast2600.rst - Use devm_* api to simplify the error cleanup. - Change hwmon register api to devm_hwmon_device_register_with_info Billy Tsai (2): dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach .../bindings/hwmon/aspeed,g6-pwm-tach.yaml | 57 ++ Documentation/hwmon/aspeed-g6-pwm-tach.rst | 24 + Documentation/hwmon/index.rst | 1 + drivers/hwmon/Kconfig | 11 + drivers/hwmon/Makefile | 1 + drivers/hwmon/aspeed-g6-pwm-tach.c | 530 ++++++++++++++++++ 6 files changed, 624 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml create mode 100644 Documentation/hwmon/aspeed-g6-pwm-tach.rst create mode 100644 drivers/hwmon/aspeed-g6-pwm-tach.c -- 2.25.1
