On Thu, 2024-05-02 at 10:30 +0200, Jiri Slaby wrote: > On 02. 05. 24, 9:55, Christoph Fritz wrote: > > This patch introduces driver support for the hexLIN USB LIN bus adapter, > > enabling LIN communication over USB for both controller and responder > > modes. The driver interfaces with the CAN_LIN framework for userland > > connectivity. > > > > For more details on the adapter, visit: https://hexdev.de/hexlin/ > > > > Tested-by: Andreas Lauser <andreas.lauser@xxxxxxxxxxxxxxxxx> > > Signed-off-by: Christoph Fritz <christoph.fritz@xxxxxxxxx> > ... > > --- /dev/null > > +++ b/drivers/hid/hid-hexdev-hexlin.c > > @@ -0,0 +1,630 @@ > ... > > +static int hexlin_stop(struct lin_device *ldev) > > +{ > > + struct hid_device *hdev = to_hid_device(ldev->dev); > > + struct hexlin_priv_data *priv = hid_get_drvdata(hdev); > > + > > + hid_hw_close(hdev); > > + > > + priv->is_error = true; > > + complete(&priv->wait_in_report); > > + > > + mutex_lock(&priv->tx_lock); > > + mutex_unlock(&priv->tx_lock); > > This is a weird way to implement a completion. It looks like you need > another one. They are not necessary, even more so when I can drop the mutex_destroy() below. > > > + return 0; > > +} > ...> +static int hexlin_probe(struct hid_device *hdev, > > + const struct hid_device_id *id) > > +{ > > + struct hexlin_priv_data *priv; > > + int ret; > > + > > + priv = devm_kzalloc(&hdev->dev, sizeof(*priv), GFP_KERNEL); > > + if (!priv) > > + return -ENOMEM; > > + > > + priv->hid_dev = hdev; > > + hid_set_drvdata(hdev, priv); > > + > > + mutex_init(&priv->tx_lock); > > + > > + ret = hid_parse(hdev); > > + if (ret) { > > + hid_err(hdev, "hid parse failed with %d\n", ret); > > + goto fail_and_free; > > + } > > + > > + ret = hid_hw_start(hdev, HID_CONNECT_DRIVER); > > + if (ret) { > > + hid_err(hdev, "hid hw start failed with %d\n", ret); > > + goto fail_and_stop; > > + } > > + > > + ret = hid_hw_open(hdev); > > + if (ret) { > > + hid_err(hdev, "hid hw open failed with %d\n", ret); > > + goto fail_and_close; > > + } > > + > > + init_completion(&priv->wait_in_report); > > + > > + hid_device_io_start(hdev); > > + > > + ret = init_hw(priv); > > + if (ret) > > + goto fail_and_close; > > + > > + priv->ldev = register_lin(&hdev->dev, &hexlin_ldo); > > + if (IS_ERR_OR_NULL(priv->ldev)) { > > + ret = PTR_ERR(priv->ldev); > > + goto fail_and_close; > > + } > > + > > + hid_hw_close(hdev); > > + > > + hid_info(hdev, "hexLIN (fw-version: %u) probed\n", priv->fw_version); > > + > > + return 0; > > + > > +fail_and_close: > > + hid_hw_close(hdev); > > +fail_and_stop: > > + hid_hw_stop(hdev); > > +fail_and_free: > > + mutex_destroy(&priv->tx_lock); > > + return ret; > > +} > > + > > +static void hexlin_remove(struct hid_device *hdev) > > +{ > > + struct hexlin_priv_data *priv = hid_get_drvdata(hdev); > > + > > + unregister_lin(priv->ldev); > > + hid_hw_stop(hdev); > > + mutex_destroy(&priv->tx_lock); > > It is unusual to destroy a mutex. Why do you do that? > Just for code clarity and it should help if someone wants to use CONFIG_DEBUG_MUTEXES. To be able to drop the lock/unlock from above, I could add the lock/unlock here or just drop the mutex_destroy() completely. I'll just drop it in upcoming v3. > > +} > ... > > +static int __init hexlin_init(void) > > +{ > > + return hid_register_driver(&hexlin_driver); > > +} > > + > > +static void __exit hexlin_exit(void) > > +{ > > + hid_unregister_driver(&hexlin_driver); > > +} > > > > > + > > +/* > > + * When compiled into the kernel, initialize after the hid bus. > > + */ > > +late_initcall(hexlin_init); > > Hmm, why not module_init() then? (And module_hid_driver().) Looking at the other hid drivers and testing with just module_hid_driver(hexlin_driver) works here fine for compiled into the kernel and as a module. > > > +module_exit(hexlin_exit); > > + > > +MODULE_LICENSE("GPL"); > > +MODULE_AUTHOR("Christoph Fritz <christoph.fritz@xxxxxxxxx>"); > > +MODULE_DESCRIPTION("LIN bus driver for hexLIN USB adapter"); Thanks -- Christoph
