On Tue, 28 Jan 2025 at 20:48, Michal Wilczynski <m.wilczynski@xxxxxxxxxxx> wrote: > > The T-Head TH1520 SoC uses an E902 co-processor running Always-On (AON) > firmware to manage power, clock, and other system resources [1]. This > patch introduces a driver implementing the AON firmware protocol, > allowing the Linux kernel to communicate with the firmware via mailbox > channels. Through an RPC-based interface, the kernel can initiate power > state transitions, update resource configurations, and perform other > AON-related tasks. > > Link: https://openbeagle.org/beaglev-ahead/beaglev-ahead/-/blob/main/docs/TH1520%20System%20User%20Manual.pdf [1] > > Signed-off-by: Michal Wilczynski <m.wilczynski@xxxxxxxxxxx> > --- [...] > + > +static int th1520_aon_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct th1520_aon_chan *aon_chan; > + struct mbox_client *cl; > + int ret; > + struct platform_device_info pdevinfo = { > + .name = "th1520-pd", > + .id = PLATFORM_DEVID_AUTO, > + .parent = dev, > + }; > + > + aon_chan = devm_kzalloc(dev, sizeof(*aon_chan), GFP_KERNEL); > + if (!aon_chan) > + return -ENOMEM; > + > + cl = &aon_chan->cl; > + cl->dev = dev; > + cl->tx_block = true; > + cl->tx_tout = MAX_TX_TIMEOUT; > + cl->rx_callback = th1520_aon_rx_callback; > + > + aon_chan->ch = mbox_request_channel_byname(cl, "aon"); > + if (IS_ERR(aon_chan->ch)) > + return dev_err_probe(dev, PTR_ERR(aon_chan->ch), > + "Failed to request aon mbox chan\n"); > + > + mutex_init(&aon_chan->transaction_lock); > + init_completion(&aon_chan->done); > + > + platform_set_drvdata(pdev, aon_chan); > + > + aon_chan->pd = platform_device_register_full(&pdevinfo); > + ret = PTR_ERR_OR_ZERO(aon_chan->pd); > + if (ret) { > + dev_err(dev, "Failed to register child device 'th1520-pd': %d\n", ret); > + goto free_mbox_chan; > + } > + > + ret = devm_of_platform_populate(dev); > + if (ret) > + goto unregister_pd; > + > + return 0; > + > +unregister_pd: > + platform_device_unregister(aon_chan->pd); > +free_mbox_chan: > + mbox_free_channel(aon_chan->ch); > + > + return ret; > +} Rather than implementing this as a driver, I suggest limiting this to a set of exported library functions. In this way, you don't need to register a platform device, but can instead let the power-domain provider driver in patch6, to be the one that matches on the "thead,th1520-aon" compatible to probe. > + > +static void th1520_aon_remove(struct platform_device *pdev) > +{ > + struct th1520_aon_chan *aon_chan = platform_get_drvdata(pdev); > + > + platform_device_unregister(aon_chan->pd); > + mbox_free_channel(aon_chan->ch); > +} > + > +static const struct of_device_id th1520_aon_match[] = { > + { .compatible = "thead,th1520-aon" }, > + { /* Sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, th1520_aon_match); > + > +static struct platform_driver th1520_aon_driver = { > + .driver = { > + .name = "th1520-aon", > + .of_match_table = th1520_aon_match, > + }, > + .probe = th1520_aon_probe, > + .remove = th1520_aon_remove, > +}; > +module_platform_driver(th1520_aon_driver); > + > +MODULE_AUTHOR("Michal Wilczynski <m.wilczynski@xxxxxxxxxxx>"); > +MODULE_DESCRIPTION("T-HEAD TH1520 Always-On firmware driver"); > +MODULE_LICENSE("GPL"); [...] Kind regards Uffe
