Hi Nishanth, On Fri, Oct 25, 2024 at 12:42:04PM GMT, Nishanth Menon wrote: > On 16:39-20241012, Markus Schneider-Pargmann wrote: > [...] > > > > The possible wakeup devices are found by checking which devices are > > powered by the regulator supplying the "vddshv_canuart" line. These are > > considered possible wakeup sources. Only wakeup sources that are > > actually enabled by the user will be considered as a an active wakeup > > source. If none of the wakeup sources are enabled the system will do a > > normal poweroff. If at least one wakeup source is enabled it will > > instead send a TI_SCI_MSG_PREPARE_SLEEP message from the sys_off > > handler. Sending this message will result in an immediate shutdown of > > the system. No execution is expected after this point. The code will > > wait for 5s and do an emergency_restart afterwards if Partial-IO wasn't > > entered at that point. > > > [...] > > > +static bool tisci_canuart_wakeup_enabled(struct ti_sci_info *info) > > +{ > > + static const char canuart_name[] = "vddshv_canuart"; > > + struct device_node *wakeup_node = NULL; > > + > > + for (wakeup_node = of_find_node_with_property(NULL, "vio-supply"); > > + wakeup_node; > > + wakeup_node = of_find_node_with_property(wakeup_node, "vio-supply")) { > > + struct device_node *supply_node; > > + const char *supply_name; > > + struct platform_device *pdev; > > + int ret; > > + > > + supply_node = of_parse_phandle(wakeup_node, "vio-supply", 0); > > + if (!supply_node) > > + continue; > > + > > + ret = of_property_read_string(supply_node, "regulator-name", &supply_name); > > + of_node_put(supply_node); > > + if (ret) { > > + dev_warn(info->dev, "Failed to parse vio-supply phandle at %pOF %d\n", > > + wakeup_node, ret); > > + continue; > > + } > > + > > + if (strncmp(canuart_name, supply_name, strlen(canuart_name))) > > + continue; > > + > > + pdev = of_find_device_by_node(wakeup_node); > > + if (!pdev) > > + continue; > > + > > + if (device_may_wakeup(&pdev->dev)) { > > + dev_dbg(info->dev, "%pOF identified as wakeup source for Partial-IO\n", > > + wakeup_node); > > + put_device(&pdev->dev); > > + of_node_put(wakeup_node); > > + return true; > > + } > > + put_device(&pdev->dev); > > + } > > + > > + return false; > > +} > > + > > What is the binding that supports this? I just do not think that > scanning the entire tree for vio-supply implies you will get thr right > property here. > > Just giving an example to illustrate this point: > Documentation/devicetree/bindings/net/wireless/ti,wl1251.txt says it > needs vio-supply -> so i have a node with the wireless supply as > vio-supply -> Since we are scanning from NULL for vio-supply, we hit > that, that is a bad choice for enabling io-retention. There is no bining that specifically supports this as I think it is not needed. The devices that are capable to wakeup the system from Partial-IO are all powered through one supply line that is always-on. It is called 'vddshv_canuart' and the name of this supply is checked in the above code as well. Yes I am using 'vio-supply', but only to search for the potential consumers of this supply. So wl1251 will be skipped in above code at if (strncmp(canuart_name, supply_name, strlen(canuart_name))) Best Markus
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