<html> <body> <pre> This document is the original design document written by Kern. Riccardo used it to implement drivers. As is always the case, the design has evolved since this document has been written and hence, it should be updated, but at least the base is here. Driver Design: The following entry points will be plugged in apcconfig.c in the UPSINFO structure depending on which driver is selected by the configuration. init_ups_port(ups) Initializes the UPS port (if any) but does not send any caracters or signals to the UPS. Equivalent to the first half of setup_serial(ups). This is very generic and the same routine can probably serve most serial UPSes. Called once at apcupsd startup, but on some devices (usb) may be called again if the device is unplugged. connect_ups(ups) Actually establishes a connection with the UPS. Sends the INITUPS signals (if any). Equivalent to the second half of setup_serial(ups) that gets and sends setup data to the UPS. Called once after init_ups_port(), but may be called again for some devices (usb) if they are unplugged. get_ups_capabilities(ups) Determines the capabilities of the UPS. Equivalent to get_apc_capabilities(ups). Called once at initialization of the UPS to determine (or set) the capabilities of the UPS i.e. sets up the UPS_cap[] array. get_ups_static_data(ups) Reads static data from UPS. This is done one time during initialization. Equivalent to read_static_ups_data(ups) plus get_apc_model(ups). Reads unchanging data from the UPS such as battery voltage, high and low transfer voltages, ... get_ups_volatile_data(ups) Reads volatile or changing data from the UPS. This is done every time in the big action loop. Equivalent to the old fillUPS(ups). get_ups_state(ups) This is the main routine that detects state changes in the UPS. After this routine is called, do_action() is called to process the state change. Equivalent to check_serial(ups). kill_ups_power(ups) Called to kill the power on the UPS. Equivalent to kill_power(ups). term_ups(ups) Called to terminate the connection with the UPS. </pre> </body> </html>
