Le 10/12/2024 à 11:45, 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 request
interrupt that will be called when the USB device receives its
interrupt pipe.
...
+int nct6694_read_msg(struct nct6694 *nct6694, u8 mod, u16 offset,
+ u16 length, void *buf)
+{
+ struct nct6694_cmd_header *cmd_header = nct6694->cmd_header;
+ struct nct6694_response_header *response_header = nct6694->response_header;
+ struct usb_device *udev = nct6694->udev;
+ int tx_len, rx_len, ret;
+
+ guard(mutex)(&nct6694->access_lock);
Nitpick: This could be moved a few lines below, should it still comply
with your coding style.
+
+ /* Send command packet to USB device */
+ cmd_header->mod = mod;
+ cmd_header->cmd = offset & 0xFF;
+ cmd_header->sel = (offset >> 8) & 0xFF;
+ cmd_header->hctrl = NCT6694_HCTRL_GET;
+ cmd_header->len = length;
+
+ ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, NCT6694_BULK_OUT_EP),
+ cmd_header, NCT6694_CMD_PACKET_SZ, &tx_len,
+ nct6694->timeout);
+ if (ret)
+ return ret;
+
+ /* Receive response packet from USB device */
+ ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, NCT6694_BULK_IN_EP),
+ response_header, NCT6694_CMD_PACKET_SZ, &rx_len,
+ nct6694->timeout);
+ if (ret)
+ return ret;
+
+ ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, NCT6694_BULK_IN_EP),
+ buf, NCT6694_MAX_PACKET_SZ, &rx_len, nct6694->timeout);
+ if (ret)
+ return ret;
+
+ return nct6694_response_err_handling(nct6694, response_header->sts);
+}
+EXPORT_SYMBOL(nct6694_read_msg);
+
+int nct6694_write_msg(struct nct6694 *nct6694, u8 mod, u16 offset,
+ u16 length, void *buf)
+{
+ struct nct6694_cmd_header *cmd_header = nct6694->cmd_header;
+ struct nct6694_response_header *response_header = nct6694->response_header;
+ struct usb_device *udev = nct6694->udev;
+ int tx_len, rx_len, ret;
+
+ guard(mutex)(&nct6694->access_lock);
Nitpick: This could be moved a few lines below, should it still comply
with your coding style.
+
+ /* Send command packet to USB device */
Nitpick: double space before */
+ cmd_header->mod = mod;
+ cmd_header->cmd = offset & 0xFF;
+ cmd_header->sel = (offset >> 8) & 0xFF;
+ cmd_header->hctrl = NCT6694_HCTRL_SET;
+ cmd_header->len = length;
...
+static struct irq_chip nct6694_irq_chip = {
const?
+ .name = "nct6694-irq",
+ .flags = IRQCHIP_SKIP_SET_WAKE,
+ .irq_bus_lock = nct6694_irq_lock,
+ .irq_bus_sync_unlock = nct6694_irq_sync_unlock,
+ .irq_enable = nct6694_irq_enable,
+ .irq_disable = nct6694_irq_disable,
+};
...
+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;
+ struct nct6694_cmd_header *cmd_header;
+ struct nct6694_response_header *response_header;
+ int pipe, maxp;
+ int ret;
+
+ interface = iface->cur_altsetting;
+
+ int_endpoint = &interface->endpoint[0].desc;
+ if (!usb_endpoint_is_int_in(int_endpoint))
+ return -ENODEV;
+
+ nct6694 = devm_kzalloc(dev, sizeof(*nct6694), GFP_KERNEL);
+ if (!nct6694)
+ return -ENOMEM;
+
+ pipe = usb_rcvintpipe(udev, NCT6694_INT_IN_EP);
+ maxp = usb_maxpacket(udev, pipe);
+
+ cmd_header = devm_kzalloc(dev, sizeof(*cmd_header),
+ GFP_KERNEL);
+ if (!cmd_header)
+ return -ENOMEM;
+
+ response_header = devm_kzalloc(dev, sizeof(*response_header),
+ GFP_KERNEL);
+ if (!response_header)
+ return -ENOMEM;
+
+ nct6694->int_buffer = devm_kcalloc(dev, NCT6694_MAX_PACKET_SZ,
+ sizeof(unsigned char), GFP_KERNEL);
Why for cmd_header and response_header we use a temp variable, while
here we update directly nct6694->int_buffer?
It would save a few LoC do remove this temp var.
+ if (!nct6694->int_buffer)
+ return -ENOMEM;
+
+ nct6694->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!nct6694->int_in_urb)
+ return -ENOMEM;
...
CJ
