Re: [PATCH v1 1/9] mfd: Add core driver for Nuvoton NCT6694

Ming Yu
2024-10-28T07:37:55Z

Hi Christophe

Thank you for your comments,
I will update the code in the next patch.

Best regards,
Ming

Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2024年10月26日 週六 下午10:58寫道：
>
> Le 24/10/2024 à 10:59, Ming Yu a écrit :
> > The Nuvoton NCT6694 is a peripheral expander with 16 GPIO chips,
> > 6 I2C controllers, 2 CANfd controllers, 2 Watchdog timers, ADC,
> > PWM, and RTC.
> >
> > This driver implements USB device functionality and shares the
> > chip's peripherals as a child device.
> >
> > Each child device can use the USB functions nct6694_read_msg()
> > and nct6694_write_msg() to issue a command. They can also register
> > a handler function that will be called when the USB device receives
> > its interrupt pipe.
> >
> > Signed-off-by: Ming Yu <tmyu0-KrzQf0k3Iz9BDgjK7y7TUQ@public.gmane.org>
> > ---
>
> ...
>
> > +static int nct6694_usb_probe(struct usb_interface *iface,
> > + const struct usb_device_id *id)
> > +{
> > + struct usb_device *udev = interface_to_usbdev(iface);
> > + struct device *dev = &udev->dev;
> > + struct usb_host_interface *interface;
> > + struct usb_endpoint_descriptor *int_endpoint;
> > + struct nct6694 *nct6694;
> > + int pipe, maxp, bulk_pipe;
> > + int ret = EINVAL;
>
> Nitpick: no need to init
>
> > +
> > + interface = iface->cur_altsetting;
> > + /* Binding interface class : 0xFF */
> > + if (interface->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
> > + interface->desc.bInterfaceSubClass != 0x00 ||
> > + interface->desc.bInterfaceProtocol != 0x00)
> > + return -ENODEV;
> > +
> > + int_endpoint = &interface->endpoint[0].desc;
> > + if (!usb_endpoint_is_int_in(int_endpoint))
> > + return -ENODEV;
> > +
> > + nct6694 = devm_kzalloc(&udev->dev, sizeof(*nct6694), GFP_KERNEL);
> > + if (!nct6694)
> > + return -ENOMEM;
> > +
> > + pipe = usb_rcvintpipe(udev, INT_IN_ENDPOINT);
> > + maxp = usb_maxpacket(udev, pipe);
> > +
> > + nct6694->cmd_buffer = devm_kcalloc(dev, CMD_PACKET_SZ,
> > + sizeof(unsigned char), GFP_KERNEL);
> > + if (!nct6694->cmd_buffer)
> > + return -ENOMEM;
> > + nct6694->rx_buffer = devm_kcalloc(dev, MAX_PACKET_SZ,
> > + sizeof(unsigned char), GFP_KERNEL);
> > + if (!nct6694->rx_buffer)
> > + return -ENOMEM;
> > + nct6694->tx_buffer = devm_kcalloc(dev, MAX_PACKET_SZ,
> > + sizeof(unsigned char), GFP_KERNEL);
> > + if (!nct6694->tx_buffer)
> > + return -ENOMEM;
> > + nct6694->int_buffer = devm_kcalloc(dev, MAX_PACKET_SZ,
> > + sizeof(unsigned char), GFP_KERNEL);
> > + if (!nct6694->int_buffer)
> > + return -ENOMEM;
> > +
> > + nct6694->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
> > + if (!nct6694->int_in_urb) {
> > + dev_err(&udev->dev, "Failed to allocate INT-in urb!\n");
> > + return -ENOMEM;
> > + }
> > +
> > + /* Bulk pipe maximum packet for each transaction */
> > + bulk_pipe = usb_sndbulkpipe(udev, BULK_OUT_ENDPOINT);
> > + nct6694->maxp = usb_maxpacket(udev, bulk_pipe);
> > +
> > + mutex_init(&nct6694->access_lock);
> > + nct6694->udev = udev;
> > + nct6694->timeout = URB_TIMEOUT; /* Wait until urb complete */
> > +
> > + INIT_LIST_HEAD(&nct6694->handler_list);
> > + spin_lock_init(&nct6694->lock);
> > +
> > + usb_fill_int_urb(nct6694->int_in_urb, udev, pipe,
> > + nct6694->int_buffer, maxp, usb_int_callback,
> > + nct6694, int_endpoint->bInterval);
> > + ret = usb_submit_urb(nct6694->int_in_urb, GFP_KERNEL);
> > + if (ret)
> > + goto err_urb;
> > +
> > + dev_set_drvdata(&udev->dev, nct6694);
> > + usb_set_intfdata(iface, nct6694);
> > +
> > + ret = mfd_add_hotplug_devices(&udev->dev, nct6694_dev,
> > + ARRAY_SIZE(nct6694_dev));
> > + if (ret) {
> > + dev_err(&udev->dev, "Failed to add mfd's child device\n");
> > + goto err_mfd;
> > + }
> > +
> > + nct6694->async_workqueue = alloc_ordered_workqueue("asyn_workqueue", 0);
>
> Missing error handling.
>
> > +
> > + dev_info(&udev->dev, "Probed device: (%04X:%04X)\n",
> > + id->idVendor, id->idProduct);
> > + return 0;
> > +
> > +err_mfd:
> > + usb_kill_urb(nct6694->int_in_urb);
> > +err_urb:
> > + usb_free_urb(nct6694->int_in_urb);
> > + return ret;
> > +}
> > +
> > +static void nct6694_usb_disconnect(struct usb_interface *iface)
> > +{
> > + struct usb_device *udev = interface_to_usbdev(iface);
> > + struct nct6694 *nct6694 = usb_get_intfdata(iface);
> > +
> > + mfd_remove_devices(&udev->dev);
> > + flush_workqueue(nct6694->async_workqueue);
> > + destroy_workqueue(nct6694->async_workqueue);
> > + usb_set_intfdata(iface, NULL);
> > + usb_kill_urb(nct6694->int_in_urb);
> > + usb_free_urb(nct6694->int_in_urb);
> > +}
> > +
> > +static const struct usb_device_id nct6694_ids[] = {
> > + { USB_DEVICE(NCT6694_VENDOR_ID, NCT6694_PRODUCT_ID)},
>
> Nitpick: space missing before the ending }
>
> > + {},
>
> Nitpick: usually, no comma is added after a {} terminator.
>
> > +};
> > +MODULE_DEVICE_TABLE(usb, nct6694_ids);
>
> ...
>
> CJ