Dear Lee,
Thank you for reviewing,
Lee Jones <lee@xxxxxxxxxx> 於 2025年3月7日 週五 上午9:15寫道：
>
> On Tue, 25 Feb 2025, Ming Yu wrote:
>
> > 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 needs to go into the Kconfig help passage.
>
Okay, I will move these to Kconfig in the next patch.
> > This driver implements USB device functionality and shares the
> > chip's peripherals as a child device.
>
> This driver doesn't implement USB functionality.
>
Fix it in v9.
> > 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.
> >
> > Signed-off-by: Ming Yu <a0282524688@xxxxxxxxx>
>
> Why aren't you signing off with your work address?
>
Fix it in v9.
> > ---
> > MAINTAINERS | 7 +
> > drivers/mfd/Kconfig | 18 ++
> > drivers/mfd/Makefile | 2 +
> > drivers/mfd/nct6694.c | 378 ++++++++++++++++++++++++++++++++++++
> > include/linux/mfd/nct6694.h | 102 ++++++++++
> > 5 files changed, 507 insertions(+)
> > create mode 100644 drivers/mfd/nct6694.c
> > create mode 100644 include/linux/mfd/nct6694.h
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 873aa2cce4d7..c700a0b96960 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -16918,6 +16918,13 @@ F: drivers/nubus/
> > F: include/linux/nubus.h
> > F: include/uapi/linux/nubus.h
> >
> > +NUVOTON NCT6694 MFD DRIVER
> > +M: Ming Yu <tmyu0@xxxxxxxxxxx>
> > +L: linux-kernel@xxxxxxxxxxxxxxx
>
> This is the default list. You shouldn't need to add that here.
>
Remove it in v9.
> > +S: Supported
> > +F: drivers/mfd/nct6694.c
> > +F: include/linux/mfd/nct6694.h
> > +
> > NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
> > M: Antonino Daplas <adaplas@xxxxxxxxx>
> > L: linux-fbdev@xxxxxxxxxxxxxxx
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index 6b0682af6e32..c97a2bdcea0b 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -1045,6 +1045,24 @@ config MFD_MENF21BMC
> > This driver can also be built as a module. If so the module
> > will be called menf21bmc.
> >
> > +config MFD_NCT6694
> > + tristate "Nuvoton NCT6694 support"
> > + select MFD_CORE
> > + depends on USB
> > + help
> > + This enables support for the Nuvoton USB device NCT6694, which shares
> > + peripherals.
> > +
> > + This driver provides core APIs to access the NCT6694 hardware
> > + monitoring and control features.
> > +
> > + The NCT6694 is a versatile multi-function device that supports
>
> Please drop the term multi-function device and replace it what a proper
> description of the devices.
>
Fix it in v9.
> > + functionalities such as GPIO, I2C, CAN, WDT, HWMON, and RTC
> > + management.
>
> All of these line breaks should be removed.
>
Fix these in v9.
> > + Additional drivers must be enabled to utilize the specific
> > + functionalities of the device.
> > +
> > config MFD_OCELOT
> > tristate "Microsemi Ocelot External Control Support"
> > depends on SPI_MASTER
> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index 9220eaf7cf12..7725b732e265 100644
> > --- a/drivers/mfd/Makefile
> > +++ b/drivers/mfd/Makefile
> > @@ -121,6 +121,8 @@ obj-$(CONFIG_MFD_MC13XXX) += mc13xxx-core.o
> > obj-$(CONFIG_MFD_MC13XXX_SPI) += mc13xxx-spi.o
> > obj-$(CONFIG_MFD_MC13XXX_I2C) += mc13xxx-i2c.o
> >
> > +obj-$(CONFIG_MFD_NCT6694) += nct6694.o
> > +
> > obj-$(CONFIG_MFD_CORE) += mfd-core.o
> >
> > ocelot-soc-objs := ocelot-core.o ocelot-spi.o
> > diff --git a/drivers/mfd/nct6694.c b/drivers/mfd/nct6694.c
> > new file mode 100644
> > index 000000000000..c82457679ca6
> > --- /dev/null
> > +++ b/drivers/mfd/nct6694.c
> > @@ -0,0 +1,378 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Nuvoton NCT6694 core driver using USB interface to provide
> > + * access to the NCT6694 hardware monitoring and control features.
> > + *
> > + * The NCT6694 is a versatile multi-function device that supports
>
> Here too.
>
Fix it in v9.
> > + * functionalities such as GPIO, I2C, CAN, WDT, HWMON and RTC
> > + * management.
> > + *
> > + * Copyright (C) 2024 Nuvoton Technology Corp.
>
> This goes at the top.
>
Fix it in v9.
> > + */
> > +
> > +#include <linux/bits.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mfd/core.h>
> > +#include <linux/mfd/nct6694.h>
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include <linux/usb.h>
> > +
> > +static const struct mfd_cell nct6694_dev[] = {
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x0),
>
> "-gpio" usually goes on the end.
>
Fix it in v9.
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x1),
>
> IDs are usually given in base-10.
>
Fix it in v9.
> Why are you manually adding the device IDs?
>
> PLATFORM_DEVID_AUTO doesn't work for you?
>
I need to manage these IDs to ensure that child devices can be
properly utilized within their respective modules.
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x2),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x3),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x4),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x5),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x6),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x7),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x8),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x9),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xA),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xB),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xC),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xD),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xE),
> > + MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xF),
> > +
> > + MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x0),
> > + MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x1),
> > + MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x2),
> > + MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x3),
> > + MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x4),
> > + MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x5),
> > +
> > + MFD_CELL_BASIC("nct6694_canfd", NULL, NULL, 0, 0x0),
>
> Why has the naming convention changed here?
>
I originally expected the child devices name to directly match its
driver name. Do you think it would be better to standardize the naming
as "nct6694-xxx" ?
> > + MFD_CELL_BASIC("nct6694_canfd", NULL, NULL, 0, 0x1),
> > +
> > + MFD_CELL_BASIC("nct6694_wdt", NULL, NULL, 0, 0x0),
> > + MFD_CELL_BASIC("nct6694_wdt", NULL, NULL, 0, 0x1),
> > +
> > + MFD_CELL_NAME("nct6694-hwmon"),
> > + MFD_CELL_NAME("rtc-nct6694"),
>
> There doesn't seem to be any consistency here.
>
Do you think these two should be changed to use MFD_CELL_BASIC()?
> > +};
> > +
> > +static int nct6694_response_err_handling(struct nct6694 *nct6694,
>
> > +{
> > + switch (err_status) {
> > + case NCT6694_NO_ERROR:
> > + return err_status;
>
> This is odd since you already know this will be 0.
>
Fix it in v9.
> > + case NCT6694_NOT_SUPPORT_ERROR:
> > + dev_warn(nct6694->dev, "Command is not supported!\n");
>
> Why not dev_err()?
>
Fix it in v9.
> > + break;
> > + case NCT6694_NO_RESPONSE_ERROR:
> > + dev_warn(nct6694->dev, "Command received no response!\n");
> > + break;
> > + case NCT6694_TIMEOUT_ERROR:
> > + dev_warn(nct6694->dev, "Command timed out!\n");
> > + break;
> > + case NCT6694_PENDING:
> > + dev_warn(nct6694->dev, "Command is pending!\n");
>
> Is this an error?
>
Yes, I will fix it to dev_err() in the next patch.
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + return -EIO;
> > +}
> > +
> > +int nct6694_read_msg(struct nct6694 *nct6694, const struct nct6694_cmd_header *cmd_hd, void *buf)
> > +{
> > + union nct6694_usb_msg *msg = nct6694->usb_msg;
> > + int tx_len, rx_len, ret;
> > +
> > + guard(mutex)(&nct6694->access_lock);
> > +
> > + /* Send command packet to USB device */
>
> This doesn't really describe the next 2 lines.
>
> Move it down?
>
Fix it in v9.
> > + memcpy(&msg->cmd_header, cmd_hd, sizeof(*cmd_hd));
> > + msg->cmd_header.hctrl = NCT6694_HCTRL_GET;
> > +
> > + ret = usb_bulk_msg(nct6694->udev,
>
> Since you use nct6694->udev a bunch - sometimes twice in the same call,
> it might be nicer to pull it into it's own variable instead of
> dereferencing it all the time.
>
Fix it in v9.
> > + usb_sndbulkpipe(nct6694->udev, NCT6694_BULK_OUT_EP),
> > + &msg->cmd_header, sizeof(*msg), &tx_len,
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + /* Receive response packet from USB device */
> > + ret = usb_bulk_msg(nct6694->udev,
> > + usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
> > + &msg->response_header, sizeof(*msg), &rx_len,
>
> How can you read sizeof(*msg) Bytes (22?) into the smaller
> response_header (16?) attribute?
>
The size of (*msg) is the same as command_header and response_header (8 bytes).
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + /* Receive data packet from USB device */
> > + ret = usb_bulk_msg(nct6694->udev,
> > + usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
> > + buf, le16_to_cpu(cmd_hd->len), &rx_len,
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + if (rx_len != le16_to_cpu(cmd_hd->len)) {
> > + dev_err(nct6694->dev, "Expected received length %d, but got %d\n",
> > + le16_to_cpu(cmd_hd->len), rx_len);
> > + return -EIO;
> > + }
> > +
> > + return nct6694_response_err_handling(nct6694, msg->response_header.sts);
> > +}
> > +EXPORT_SYMBOL(nct6694_read_msg);
> > +
> > +int nct6694_write_msg(struct nct6694 *nct6694, const struct nct6694_cmd_header *cmd_hd, void *buf)
> > +{
> > + union nct6694_usb_msg *msg = nct6694->usb_msg;
> > + int tx_len, rx_len, ret;
> > +
> > + guard(mutex)(&nct6694->access_lock);
> > +
> > + /* Send command packet to USB device */
> > + memcpy(&msg->cmd_header, cmd_hd, sizeof(*cmd_hd));
> > + msg->cmd_header.hctrl = NCT6694_HCTRL_SET;
> > +
> > + ret = usb_bulk_msg(nct6694->udev,
> > + usb_sndbulkpipe(nct6694->udev, NCT6694_BULK_OUT_EP),
> > + &msg->cmd_header, sizeof(*msg), &tx_len,
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + /* Send data packet to USB device */
> > + ret = usb_bulk_msg(nct6694->udev,
> > + usb_sndbulkpipe(nct6694->udev, NCT6694_BULK_OUT_EP),
> > + buf, le16_to_cpu(cmd_hd->len), &tx_len,
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + /* Receive response packet from USB device */
> > + ret = usb_bulk_msg(nct6694->udev,
> > + usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
> > + &msg->response_header, sizeof(*msg), &rx_len,
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + /* Receive data packet from USB device */
> > + ret = usb_bulk_msg(nct6694->udev,
> > + usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
> > + buf, le16_to_cpu(cmd_hd->len), &rx_len,
> > + nct6694->timeout);
> > + if (ret)
> > + return ret;
> > +
> > + if (rx_len != le16_to_cpu(cmd_hd->len)) {
> > + dev_err(nct6694->dev, "Expected transmitted length %d, but got %d\n",
> > + le16_to_cpu(cmd_hd->len), rx_len);
> > + return -EIO;
> > + }
> > +
> > + return nct6694_response_err_handling(nct6694, msg->response_header.sts);
> > +}
> > +EXPORT_SYMBOL(nct6694_write_msg);
> > +
> > +static void usb_int_callback(struct urb *urb)
> > +{
> > + struct nct6694 *nct6694 = urb->context;
> > + unsigned int *int_status = urb->transfer_buffer;
> > + int ret;
> > +
> > + switch (urb->status) {
> > + case 0:
> > + break;
> > + case -ECONNRESET:
> > + case -ENOENT:
> > + case -ESHUTDOWN:
> > + return;
> > + default:
> > + generic_handle_irq_safe(irq_find_mapping(nct6694->domain, irq));
> > + *int_status &= ~BIT(irq);
> > + }
> > +
> > +resubmit:
> > + ret = usb_submit_urb(urb, GFP_ATOMIC);
> > + if (ret)
> > + dev_dbg(nct6694->dev, "%s: Failed to resubmit urb, status %pe",
>
> Why debug?
>
Excuse me, do you think it should change to dev_err()?
> > + __func__, ERR_PTR(ret));
>
> Remove the __func__ part.
>
Understood.
> > +}
> > +
...
> > +static int nct6694_usb_probe(struct usb_interface *iface,
> > + const struct usb_device_id *id)
> > +{
> > + struct usb_device *udev = interface_to_usbdev(iface);
> > + struct usb_endpoint_descriptor *int_endpoint;
> > + struct usb_host_interface *interface;
> > + struct device *dev = &iface->dev;
> > + struct nct6694 *nct6694;
> > + int pipe, maxp;
> > + int ret;
> > +
> > + 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);
> > +
> > + nct6694->usb_msg = devm_kzalloc(dev, sizeof(union nct6694_usb_msg), GFP_KERNEL);
> > + if (!nct6694->usb_msg)
> > + return -ENOMEM;
> > +
> > + nct6694->int_buffer = devm_kzalloc(dev, maxp, GFP_KERNEL);
> > + if (!nct6694->int_buffer)
> > + return -ENOMEM;
> > +
> > + nct6694->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
> > + if (!nct6694->int_in_urb)
> > + return -ENOMEM;
> > +
> > + nct6694->domain = irq_domain_add_simple(NULL, NCT6694_NR_IRQS, 0,
> > + &nct6694_irq_domain_ops,
> > + nct6694);
> > + if (!nct6694->domain) {
> > + ret = -ENODEV;
> > + goto err_urb;
> > + }
> > +
> > + nct6694->dev = dev;
> > + nct6694->udev = udev;
> > + nct6694->timeout = NCT6694_URB_TIMEOUT; /* Wait until URB completes */
>
> No need to save this known value.
>
Understood, I will drop it in the next patch.
> > + ret = devm_mutex_init(dev, &nct6694->access_lock);
> > + if (ret)
> > + goto err_urb;
> > +
> > + ret = devm_mutex_init(dev, &nct6694->irq_lock);
> > + if (ret)
> > + goto err_urb;
> > +
> > + interface = iface->cur_altsetting;
> > + int_endpoint = &interface->endpoint[0].desc;
> > + if (!usb_endpoint_is_int_in(int_endpoint)) {
> > + ret = -ENODEV;
> > + goto err_urb;
> > + }
> > + 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;
>
> Please unsquash these calls - space them out.
>
Fix these in v9.
> > +
> > + usb_set_intfdata(iface, nct6694);
> > +
> > + ret = mfd_add_hotplug_devices(dev, nct6694_dev, ARRAY_SIZE(nct6694_dev));
> > + if (ret)
> > + goto err_mfd;
> > +
> > + 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 nct6694 *nct6694 = usb_get_intfdata(iface);
> > +
> > + mfd_remove_devices(nct6694->dev);
> > + usb_kill_urb(nct6694->int_in_urb);
> > + usb_free_urb(nct6694->int_in_urb);
> > +}
> > +
> > +static const struct usb_device_id nct6694_ids[] = {
> > + { USB_DEVICE_AND_INTERFACE_INFO(NCT6694_VENDOR_ID,
> > + NCT6694_PRODUCT_ID,
> > + 0xFF, 0x00, 0x00)},
>
> This should fit on one line. You can use up to 100-chars.
>
Fix it in v9.
> > + {}
> > +};
> > +MODULE_DEVICE_TABLE(usb, nct6694_ids);
> > +
> > +static struct usb_driver nct6694_usb_driver = {
> > + .name = "nct6694",
>
> Odd spaces.
>
Fix it in v9.
> > + .id_table = nct6694_ids,
> > + .probe = nct6694_usb_probe,
> > + .disconnect = nct6694_usb_disconnect,
> > +};
> > +
>
> Remove this line.
>
Fix it in v9.
> > +module_usb_driver(nct6694_usb_driver);
> > +
> > +MODULE_DESCRIPTION("USB core driver for NCT6694");
>
> This is not a USB driver.
>
Fix it in v9.
> > +MODULE_AUTHOR("Ming Yu <tmyu0@xxxxxxxxxxx>");
>
> Different to SoB.
>
Fix it in v9.
> > +MODULE_LICENSE("GPL");
> > diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
> > new file mode 100644
> > index 000000000000..8171f975761e
> > --- /dev/null
> > +++ b/include/linux/mfd/nct6694.h
> > @@ -0,0 +1,102 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Nuvoton NCT6694 USB transaction and data structure.
> > + *
> > + * Copyright (C) 2024 Nuvoton Technology Corp.
>
> At the top.
>
Fix it in v9.
> > + */
> > +
Best regards,
Ming
