diff mbox series

[v5,1/7] mfd: Add core driver for Nuvoton NCT6694

Message ID 20250114033010.2445925-2-a0282524688@gmail.com
State New
Headers show
Series Add Nuvoton NCT6694 MFD drivers | expand

Commit Message

Ming Yu Jan. 14, 2025, 3:30 a.m. UTC
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.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                 |   7 +
 drivers/mfd/Kconfig         |  10 +
 drivers/mfd/Makefile        |   2 +
 drivers/mfd/nct6694.c       | 388 ++++++++++++++++++++++++++++++++++++
 include/linux/mfd/nct6694.h | 109 ++++++++++
 5 files changed, 516 insertions(+)
 create mode 100644 drivers/mfd/nct6694.c
 create mode 100644 include/linux/mfd/nct6694.h

Comments

Lee Jones Jan. 15, 2025, 4:04 p.m. UTC | #1
On Tue, 14 Jan 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 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.
> 
> Signed-off-by: Ming Yu <a0282524688@gmail.com>
> ---
>  MAINTAINERS                 |   7 +
>  drivers/mfd/Kconfig         |  10 +
>  drivers/mfd/Makefile        |   2 +
>  drivers/mfd/nct6694.c       | 388 ++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/nct6694.h | 109 ++++++++++
>  5 files changed, 516 insertions(+)
>  create mode 100644 drivers/mfd/nct6694.c
>  create mode 100644 include/linux/mfd/nct6694.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a87ddad78e26..79568f82b98a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16717,6 +16717,13 @@ F:	drivers/nubus/
>  F:	include/linux/nubus.h
>  F:	include/uapi/linux/nubus.h
>  
> +NUVOTON NCT6694 MFD DRIVER
> +M:	Ming Yu <tmyu0@nuvoton.com>
> +L:	linux-kernel@vger.kernel.org
> +S:	Supported
> +F:	drivers/mfd/nct6694.c
> +F:	include/linux/mfd/nct6694.h
> +
>  NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
>  M:	Antonino Daplas <adaplas@gmail.com>
>  L:	linux-fbdev@vger.kernel.org
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index ae23b317a64e..3e641bfeeb38 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1045,6 +1045,16 @@ 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 adds support for Nuvoton USB device NCT6694 sharing peripherals

Missing full stop.

> +	  This includes the USB device driver and core APIs.
> +	  Additional drivers must be enabled in order to use the functionality

New sentences do not have to be on new lines.

> +	  of the device.

Please explain what this functionality is.

> +
>  config MFD_OCELOT
>  	tristate "Microsemi Ocelot External Control Support"
>  	depends on SPI_MASTER
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index e057d6d6faef..3c902d3704dc 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..294b6b7a902e
> --- /dev/null
> +++ b/drivers/mfd/nct6694.c
> @@ -0,0 +1,388 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Nuvoton NCT6694 MFD driver based on USB interface.

No such thing as an MFD driver.  What is this device?

> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + */
> +
> +#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>
> +
> +#define MFD_DEV_SIMPLE(_name)				\
> +{							\
> +	.name = NCT6694_DEV_##_name,			\

Device names are usually lower case.

> +}							\

MFD_CELL_NAME()

> +#define MFD_DEV_WITH_ID(_name, _id)			\
> +{							\
> +	.name = NCT6694_DEV_##_name,			\
> +	.id = _id,					\
> +}

MFD_CELL_BASIC()

Or add a new one to include/linux/mfd/core.h.

> +/* MFD device resources */

This comment is superfluous.

> +static const struct mfd_cell nct6694_dev[] = {
> +	MFD_DEV_WITH_ID(GPIO, 0x0),

Why doesn't PLATFORM_DEVID_AUTO work for you?

> +	MFD_DEV_WITH_ID(GPIO, 0x1),
> +	MFD_DEV_WITH_ID(GPIO, 0x2),
> +	MFD_DEV_WITH_ID(GPIO, 0x3),
> +	MFD_DEV_WITH_ID(GPIO, 0x4),
> +	MFD_DEV_WITH_ID(GPIO, 0x5),
> +	MFD_DEV_WITH_ID(GPIO, 0x6),
> +	MFD_DEV_WITH_ID(GPIO, 0x7),
> +	MFD_DEV_WITH_ID(GPIO, 0x8),
> +	MFD_DEV_WITH_ID(GPIO, 0x9),
> +	MFD_DEV_WITH_ID(GPIO, 0xA),
> +	MFD_DEV_WITH_ID(GPIO, 0xB),
> +	MFD_DEV_WITH_ID(GPIO, 0xC),
> +	MFD_DEV_WITH_ID(GPIO, 0xD),
> +	MFD_DEV_WITH_ID(GPIO, 0xE),
> +	MFD_DEV_WITH_ID(GPIO, 0xF),
> +
> +	MFD_DEV_WITH_ID(I2C, 0x0),
> +	MFD_DEV_WITH_ID(I2C, 0x1),
> +	MFD_DEV_WITH_ID(I2C, 0x2),
> +	MFD_DEV_WITH_ID(I2C, 0x3),
> +	MFD_DEV_WITH_ID(I2C, 0x4),
> +	MFD_DEV_WITH_ID(I2C, 0x5),
> +
> +	MFD_DEV_WITH_ID(CAN, 0x0),
> +	MFD_DEV_WITH_ID(CAN, 0x1),
> +
> +	MFD_DEV_WITH_ID(WDT, 0x0),
> +	MFD_DEV_WITH_ID(WDT, 0x1),
> +
> +	MFD_DEV_SIMPLE(HWMON),
> +	MFD_DEV_SIMPLE(RTC),
> +};
> +
> +static int nct6694_response_err_handling(struct nct6694 *nct6694,
> +					 unsigned char err_status)
> +{
> +	struct device *dev = &nct6694->udev->dev;
> +
> +	switch (err_status) {
> +	case NCT6694_NO_ERROR:
> +		return err_status;
> +	case NCT6694_NOT_SUPPORT_ERROR:
> +		dev_dbg(dev, "%s: Command is not supported!\n", __func__);

These should be dev_warns().

__func__ shouldn't be used in production code.

Users don't care about functions.

> +		break;
> +	case NCT6694_NO_RESPONSE_ERROR:
> +		dev_dbg(dev, "%s: Command received no response!\n", __func__);
> +		break;
> +	case NCT6694_TIMEOUT_ERROR:
> +		dev_dbg(dev, "%s: Command timed out!\n", __func__);
> +		break;
> +	case NCT6694_PENDING:
> +		dev_dbg(dev, "%s: Command is pending!\n", __func__);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return -EIO;
> +}
> +
> +int nct6694_read_msg(struct nct6694 *nct6694,
> +		     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_GET;
> +
> +	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;
> +
> +	/* 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_dbg(&nct6694->udev->dev, "%s: Received length is not match!\n",

"does not match <something>"

> +			__func__);

This should be dev_err().

> +		return -EIO;
> +	}
> +
> +	return nct6694_response_err_handling(nct6694, msg->response_header.sts);
> +}
> +EXPORT_SYMBOL(nct6694_read_msg);
> +
> +int nct6694_write_msg(struct nct6694 *nct6694, 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_dbg(&nct6694->udev->dev, "%s: Sent length is not match!\n",
> +			__func__);

This should be dev_err().

> +		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;
> +	struct device *dev = &nct6694->udev->dev;
> +	unsigned int *int_status = urb->transfer_buffer;
> +	int ret;
> +
> +	switch (urb->status) {
> +	case 0:
> +		break;
> +	case -ECONNRESET:
> +	case -ENOENT:
> +	case -ESHUTDOWN:
> +		return;
> +	default:
> +		goto resubmit;
> +	}
> +
> +	while (*int_status) {
> +		int irq = __ffs(*int_status);
> +
> +		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(dev, "%s: Failed to resubmit urb, status %pe",
> +			__func__, ERR_PTR(ret));
> +}
> +
> +static void nct6694_irq_lock(struct irq_data *data)
> +{
> +	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> +
> +	mutex_lock(&nct6694->irq_lock);
> +}
> +
> +static void nct6694_irq_sync_unlock(struct irq_data *data)
> +{
> +	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> +
> +	mutex_unlock(&nct6694->irq_lock);
> +}
> +
> +static void nct6694_irq_enable(struct irq_data *data)
> +{
> +	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> +	irq_hw_number_t hwirq = irqd_to_hwirq(data);
> +
> +	nct6694->irq_enable |= BIT(hwirq);

Changing a bit mask doesn't actually {en,dis}able an IRQ, right?

> +}
> +
> +static void nct6694_irq_disable(struct irq_data *data)
> +{
> +	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> +	irq_hw_number_t hwirq = irqd_to_hwirq(data);
> +
> +	nct6694->irq_enable &= ~BIT(hwirq);
> +}
> +
> +static struct irq_chip nct6694_irq_chip = {
> +	.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_irq_domain_map(struct irq_domain *d, unsigned int irq,
> +				  irq_hw_number_t hw)
> +{
> +	struct nct6694 *nct6694 = d->host_data;
> +
> +	irq_set_chip_data(irq, nct6694);
> +	irq_set_chip_and_handler(irq, &nct6694_irq_chip, handle_simple_irq);
> +
> +	return 0;
> +}
> +
> +static void nct6694_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
> +{
> +	irq_set_chip_and_handler(irq, NULL, NULL);
> +	irq_set_chip_data(irq, NULL);
> +}
> +
> +static const struct irq_domain_ops nct6694_irq_domain_ops = {
> +	.map	= nct6694_irq_domain_map,
> +	.unmap	= nct6694_irq_domain_unmap,
> +};
> +
> +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 = &udev->dev;
> +	struct nct6694 *nct6694;
> +	int pipe, maxp;
> +	int ret;
> +
> +	interface = iface->cur_altsetting;

Initialise this during allocation.

> +	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);
> +
> +	nct6694->usb_msg = devm_kzalloc(dev, sizeof(union nct6694_usb_msg),
> +					GFP_KERNEL);

Unwrap this - you can use up to 100-chars.

> +	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->udev = udev;
> +	nct6694->timeout = NCT6694_URB_TIMEOUT;	/* Wait until urb complete */

"URB completes"?

> +
> +	devm_mutex_init(dev, &nct6694->access_lock);
> +	devm_mutex_init(dev, &nct6694->irq_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(dev, nct6694);
> +	usb_set_intfdata(iface, nct6694);

These two do the same thing.  You don't need both.

> +	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 usb_device *udev = interface_to_usbdev(iface);
> +	struct nct6694 *nct6694 = usb_get_intfdata(iface);
> +
> +	mfd_remove_devices(&udev->dev);

Does devm_* work here?

> +	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)},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(usb, nct6694_ids);
> +
> +static struct usb_driver nct6694_usb_driver = {
> +	.name	= "nct6694",
> +	.id_table = nct6694_ids,
> +	.probe = nct6694_usb_probe,
> +	.disconnect = nct6694_usb_disconnect,
> +};
> +
> +module_usb_driver(nct6694_usb_driver);
> +
> +MODULE_DESCRIPTION("USB-MFD driver for NCT6694");

Remove all references to MFD.

> +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
> new file mode 100644
> index 000000000000..67ca835589ad
> --- /dev/null
> +++ b/include/linux/mfd/nct6694.h
> @@ -0,0 +1,109 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Nuvoton NCT6694 USB transaction and data structure.
> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + */
> +
> +#ifndef __MFD_NCT6694_H
> +#define __MFD_NCT6694_H
> +
> +#define NCT6694_DEV_GPIO	"nct6694-gpio"
> +#define NCT6694_DEV_I2C		"nct6694-i2c"
> +#define NCT6694_DEV_CAN		"nct6694-can"
> +#define NCT6694_DEV_WDT		"nct6694-wdt"
> +#define NCT6694_DEV_HWMON	"nct6694-hwmon"
> +#define NCT6694_DEV_RTC		"nct6694-rtc"

Use raw strings in place please.

> +#define NCT6694_VENDOR_ID	0x0416
> +#define NCT6694_PRODUCT_ID	0x200B
> +#define NCT6694_INT_IN_EP	0x81
> +#define NCT6694_BULK_IN_EP	0x02
> +#define NCT6694_BULK_OUT_EP	0x03
> +
> +#define NCT6694_HCTRL_SET	0x40
> +#define NCT6694_HCTRL_GET	0x80
> +
> +#define NCT6694_URB_TIMEOUT	1000
> +
> +enum nct6694_irq_id {

These are never used.

> +	NCT6694_IRQ_GPIO0 = 0,
> +	NCT6694_IRQ_GPIO1,
> +	NCT6694_IRQ_GPIO2,
> +	NCT6694_IRQ_GPIO3,
> +	NCT6694_IRQ_GPIO4,
> +	NCT6694_IRQ_GPIO5,
> +	NCT6694_IRQ_GPIO6,
> +	NCT6694_IRQ_GPIO7,
> +	NCT6694_IRQ_GPIO8,
> +	NCT6694_IRQ_GPIO9,
> +	NCT6694_IRQ_GPIOA,
> +	NCT6694_IRQ_GPIOB,
> +	NCT6694_IRQ_GPIOC,
> +	NCT6694_IRQ_GPIOD,
> +	NCT6694_IRQ_GPIOE,
> +	NCT6694_IRQ_GPIOF,
> +	NCT6694_IRQ_CAN1,
> +	NCT6694_IRQ_CAN2,
> +	NCT6694_IRQ_RTC,
> +	NCT6694_NR_IRQS,
> +};
> +
> +enum nct6694_response_err_status {
> +	NCT6694_NO_ERROR = 0,
> +	NCT6694_FORMAT_ERROR,
> +	NCT6694_RESERVED1,
> +	NCT6694_RESERVED2,
> +	NCT6694_NOT_SUPPORT_ERROR,
> +	NCT6694_NO_RESPONSE_ERROR,
> +	NCT6694_TIMEOUT_ERROR,
> +	NCT6694_PENDING,
> +};
> +
> +struct __packed nct6694_cmd_header {
> +	u8 rsv1;
> +	u8 mod;
> +	union __packed {
> +		__le16 offset;
> +		struct __packed {
> +			u8 cmd;
> +			u8 sel;
> +		};
> +	};
> +	u8 hctrl;
> +	u8 rsv2;
> +	__le16 len;
> +};
> +
> +struct __packed nct6694_response_header {
> +	u8 sequence_id;
> +	u8 sts;
> +	u8 reserved[4];
> +	__le16 len;
> +};
> +
> +union __packed nct6694_usb_msg {
> +	struct nct6694_cmd_header cmd_header;
> +	struct nct6694_response_header response_header;
> +};
> +
> +struct nct6694 {

Do all of these values need to be stored?

> +	struct usb_device *udev;
> +	struct urb *int_in_urb;
> +	struct irq_domain *domain;
> +	struct mutex access_lock;
> +	struct mutex irq_lock;
> +	union nct6694_usb_msg *usb_msg;
> +	unsigned char *int_buffer;
> +	unsigned int irq_enable;
> +	/* time in msec to wait for the urb to the complete */

"Time"  "URB"
> +	long timeout;
> +};
> +
> +int nct6694_read_msg(struct nct6694 *nct6694, struct nct6694_cmd_header *cmd_hd,
> +		     void *buf);
> +
> +int nct6694_write_msg(struct nct6694 *nct6694, struct nct6694_cmd_header *cmd_hd,
> +		      void *buf);
> +
> +#endif
> -- 
> 2.34.1
>
Ming Yu Jan. 16, 2025, 2:28 a.m. UTC | #2
Dear Lee,

Thank you for your comments,

Lee Jones <lee@kernel.org> 於 2025年1月16日 週四 上午12:04寫道:
...
> > +config MFD_NCT6694
> > +     tristate "Nuvoton NCT6694 support"
> > +     select MFD_CORE
> > +     depends on USB
> > +     help
> > +       This adds support for Nuvoton USB device NCT6694 sharing peripherals
>
> Missing full stop.
>
> > +       This includes the USB device driver and core APIs.
> > +       Additional drivers must be enabled in order to use the functionality
>
> New sentences do not have to be on new lines.
>
> > +       of the device.
>
> Please explain what this functionality is.
>

Okay! I will fix these in the next patch.

> > +
> >  config MFD_OCELOT
> >       tristate "Microsemi Ocelot External Control Support"
> >       depends on SPI_MASTER
> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index e057d6d6faef..3c902d3704dc 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..294b6b7a902e
> > --- /dev/null
> > +++ b/drivers/mfd/nct6694.c
> > @@ -0,0 +1,388 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Nuvoton NCT6694 MFD driver based on USB interface.
>
> No such thing as an MFD driver.  What is this device?
>

Fix it in the v6.

> > + *
> > + * Copyright (C) 2024 Nuvoton Technology Corp.
> > + */
> > +
> > +#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>
> > +
> > +#define MFD_DEV_SIMPLE(_name)                                \
> > +{                                                    \
> > +     .name = NCT6694_DEV_##_name,                    \
>
> Device names are usually lower case.
>
> > +}                                                    \
>
> MFD_CELL_NAME()
>

Fix it in the v6.

> > +#define MFD_DEV_WITH_ID(_name, _id)                  \
> > +{                                                    \
> > +     .name = NCT6694_DEV_##_name,                    \
> > +     .id = _id,                                      \
> > +}
>
> MFD_CELL_BASIC()
>
> Or add a new one to include/linux/mfd/core.h.
>

Fix it in the v6.

> > +/* MFD device resources */
>
> This comment is superfluous.
>

Drop it in the v6.

> > +static const struct mfd_cell nct6694_dev[] = {
> > +     MFD_DEV_WITH_ID(GPIO, 0x0),
>
> Why doesn't PLATFORM_DEVID_AUTO work for you?
>

I need to manage these IDs to ensure that child devices can be
properly utilized within their respective modules.

> > +     MFD_DEV_WITH_ID(GPIO, 0x1),
> > +     MFD_DEV_WITH_ID(GPIO, 0x2),
> > +     MFD_DEV_WITH_ID(GPIO, 0x3),
> > +     MFD_DEV_WITH_ID(GPIO, 0x4),
> > +     MFD_DEV_WITH_ID(GPIO, 0x5),
> > +     MFD_DEV_WITH_ID(GPIO, 0x6),
> > +     MFD_DEV_WITH_ID(GPIO, 0x7),
> > +     MFD_DEV_WITH_ID(GPIO, 0x8),
> > +     MFD_DEV_WITH_ID(GPIO, 0x9),
> > +     MFD_DEV_WITH_ID(GPIO, 0xA),
> > +     MFD_DEV_WITH_ID(GPIO, 0xB),
> > +     MFD_DEV_WITH_ID(GPIO, 0xC),
> > +     MFD_DEV_WITH_ID(GPIO, 0xD),
> > +     MFD_DEV_WITH_ID(GPIO, 0xE),
> > +     MFD_DEV_WITH_ID(GPIO, 0xF),
> > +
> > +     MFD_DEV_WITH_ID(I2C, 0x0),
> > +     MFD_DEV_WITH_ID(I2C, 0x1),
> > +     MFD_DEV_WITH_ID(I2C, 0x2),
> > +     MFD_DEV_WITH_ID(I2C, 0x3),
> > +     MFD_DEV_WITH_ID(I2C, 0x4),
> > +     MFD_DEV_WITH_ID(I2C, 0x5),
> > +
> > +     MFD_DEV_WITH_ID(CAN, 0x0),
> > +     MFD_DEV_WITH_ID(CAN, 0x1),
> > +
> > +     MFD_DEV_WITH_ID(WDT, 0x0),
> > +     MFD_DEV_WITH_ID(WDT, 0x1),
> > +
> > +     MFD_DEV_SIMPLE(HWMON),
> > +     MFD_DEV_SIMPLE(RTC),
> > +};
> > +
> > +static int nct6694_response_err_handling(struct nct6694 *nct6694,
> > +                                      unsigned char err_status)
> > +{
> > +     struct device *dev = &nct6694->udev->dev;
> > +
> > +     switch (err_status) {
> > +     case NCT6694_NO_ERROR:
> > +             return err_status;
> > +     case NCT6694_NOT_SUPPORT_ERROR:
> > +             dev_dbg(dev, "%s: Command is not supported!\n", __func__);
>
> These should be dev_warns().
>
> __func__ shouldn't be used in production code.
>
> Users don't care about functions.
>

Fix it in the v6.

> > +             break;
> > +     case NCT6694_NO_RESPONSE_ERROR:
> > +             dev_dbg(dev, "%s: Command received no response!\n", __func__);
> > +             break;
> > +     case NCT6694_TIMEOUT_ERROR:
> > +             dev_dbg(dev, "%s: Command timed out!\n", __func__);
> > +             break;
> > +     case NCT6694_PENDING:
> > +             dev_dbg(dev, "%s: Command is pending!\n", __func__);
> > +             break;
> > +     default:
> > +             return -EINVAL;
> > +     }
> > +
> > +     return -EIO;
> > +}
> > +
> > +int nct6694_read_msg(struct nct6694 *nct6694,
> > +                  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_GET;
> > +
> > +     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;
> > +
> > +     /* 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_dbg(&nct6694->udev->dev, "%s: Received length is not match!\n",
>
> "does not match <something>"
>

Fix it in the v6.

> > +                     __func__);
>
> This should be dev_err().
>

Fix it in the v6.

> > +             return -EIO;
> > +     }
> > +
> > +     return nct6694_response_err_handling(nct6694, msg->response_header.sts);
> > +}
> > +EXPORT_SYMBOL(nct6694_read_msg);
> > +
> > +int nct6694_write_msg(struct nct6694 *nct6694, 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_dbg(&nct6694->udev->dev, "%s: Sent length is not match!\n",
> > +                     __func__);
>
> This should be dev_err().
>

Fix it in the v6.

> > +             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;
> > +     struct device *dev = &nct6694->udev->dev;
> > +     unsigned int *int_status = urb->transfer_buffer;
> > +     int ret;
> > +
> > +     switch (urb->status) {
> > +     case 0:
> > +             break;
> > +     case -ECONNRESET:
> > +     case -ENOENT:
> > +     case -ESHUTDOWN:
> > +             return;
> > +     default:
> > +             goto resubmit;
> > +     }
> > +
> > +     while (*int_status) {
> > +             int irq = __ffs(*int_status);
> > +
> > +             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(dev, "%s: Failed to resubmit urb, status %pe",
> > +                     __func__, ERR_PTR(ret));
> > +}
> > +
> > +static void nct6694_irq_lock(struct irq_data *data)
> > +{
> > +     struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> > +
> > +     mutex_lock(&nct6694->irq_lock);
> > +}
> > +
> > +static void nct6694_irq_sync_unlock(struct irq_data *data)
> > +{
> > +     struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> > +
> > +     mutex_unlock(&nct6694->irq_lock);
> > +}
> > +
> > +static void nct6694_irq_enable(struct irq_data *data)
> > +{
> > +     struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> > +     irq_hw_number_t hwirq = irqd_to_hwirq(data);
> > +
> > +     nct6694->irq_enable |= BIT(hwirq);
>
> Changing a bit mask doesn't actually {en,dis}able an IRQ, right?
>

Yes, it's only used to record irq.

> > +}
> > +
> > +static void nct6694_irq_disable(struct irq_data *data)
> > +{
> > +     struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
> > +     irq_hw_number_t hwirq = irqd_to_hwirq(data);
> > +
> > +     nct6694->irq_enable &= ~BIT(hwirq);
> > +}
> > +
> > +static struct irq_chip nct6694_irq_chip = {
> > +     .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_irq_domain_map(struct irq_domain *d, unsigned int irq,
> > +                               irq_hw_number_t hw)
> > +{
> > +     struct nct6694 *nct6694 = d->host_data;
> > +
> > +     irq_set_chip_data(irq, nct6694);
> > +     irq_set_chip_and_handler(irq, &nct6694_irq_chip, handle_simple_irq);
> > +
> > +     return 0;
> > +}
> > +
> > +static void nct6694_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
> > +{
> > +     irq_set_chip_and_handler(irq, NULL, NULL);
> > +     irq_set_chip_data(irq, NULL);
> > +}
> > +
> > +static const struct irq_domain_ops nct6694_irq_domain_ops = {
> > +     .map    = nct6694_irq_domain_map,
> > +     .unmap  = nct6694_irq_domain_unmap,
> > +};
> > +
> > +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 = &udev->dev;
> > +     struct nct6694 *nct6694;
> > +     int pipe, maxp;
> > +     int ret;
> > +
> > +     interface = iface->cur_altsetting;
>
> Initialise this during allocation.
>

Should these be moved before usb_fill_int_urb()?

> > +     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);
> > +
> > +     nct6694->usb_msg = devm_kzalloc(dev, sizeof(union nct6694_usb_msg),
> > +                                     GFP_KERNEL);
>
> Unwrap this - you can use up to 100-chars.
>

Fix it in the v6.

> > +     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->udev = udev;
> > +     nct6694->timeout = NCT6694_URB_TIMEOUT; /* Wait until urb complete */
>
> "URB completes"?
>

Fix it in the v6.

> > +
> > +     devm_mutex_init(dev, &nct6694->access_lock);
> > +     devm_mutex_init(dev, &nct6694->irq_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(dev, nct6694);
> > +     usb_set_intfdata(iface, nct6694);
>
> These two do the same thing.  You don't need both.
>

Fix it in the v6.

> > +     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 usb_device *udev = interface_to_usbdev(iface);
> > +     struct nct6694 *nct6694 = usb_get_intfdata(iface);
> > +
> > +     mfd_remove_devices(&udev->dev);
>
> Does devm_* work here?
>

No, or do you think mfd_add_hotplug_devices() should be replaced with
devm_mfd_add_devices()?

> > +     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)},
> > +     {}
> > +};
> > +MODULE_DEVICE_TABLE(usb, nct6694_ids);
> > +
> > +static struct usb_driver nct6694_usb_driver = {
> > +     .name   = "nct6694",
> > +     .id_table = nct6694_ids,
> > +     .probe = nct6694_usb_probe,
> > +     .disconnect = nct6694_usb_disconnect,
> > +};
> > +
> > +module_usb_driver(nct6694_usb_driver);
> > +
> > +MODULE_DESCRIPTION("USB-MFD driver for NCT6694");
>
> Remove all references to MFD.
>

Fix it in the v6.

> > +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> > +MODULE_LICENSE("GPL");
> > diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
> > new file mode 100644
> > index 000000000000..67ca835589ad
> > --- /dev/null
> > +++ b/include/linux/mfd/nct6694.h
> > @@ -0,0 +1,109 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Nuvoton NCT6694 USB transaction and data structure.
> > + *
> > + * Copyright (C) 2024 Nuvoton Technology Corp.
> > + */
> > +
> > +#ifndef __MFD_NCT6694_H
> > +#define __MFD_NCT6694_H
> > +
> > +#define NCT6694_DEV_GPIO     "nct6694-gpio"
> > +#define NCT6694_DEV_I2C              "nct6694-i2c"
> > +#define NCT6694_DEV_CAN              "nct6694-can"
> > +#define NCT6694_DEV_WDT              "nct6694-wdt"
> > +#define NCT6694_DEV_HWMON    "nct6694-hwmon"
> > +#define NCT6694_DEV_RTC              "nct6694-rtc"
>
> Use raw strings in place please.
>

Fix it in the v6.

> > +#define NCT6694_VENDOR_ID    0x0416
> > +#define NCT6694_PRODUCT_ID   0x200B
> > +#define NCT6694_INT_IN_EP    0x81
> > +#define NCT6694_BULK_IN_EP   0x02
> > +#define NCT6694_BULK_OUT_EP  0x03
> > +
> > +#define NCT6694_HCTRL_SET    0x40
> > +#define NCT6694_HCTRL_GET    0x80
> > +
> > +#define NCT6694_URB_TIMEOUT  1000
> > +
> > +enum nct6694_irq_id {
>
> These are never used.
>

Some of these numbers ared used by child devices to map the irq_domain.
(e.g. NCT6694_IRQ_CAN1, NCT6694_IRQ_RTC)

> > +     NCT6694_IRQ_GPIO0 = 0,
> > +     NCT6694_IRQ_GPIO1,
> > +     NCT6694_IRQ_GPIO2,
> > +     NCT6694_IRQ_GPIO3,
> > +     NCT6694_IRQ_GPIO4,
> > +     NCT6694_IRQ_GPIO5,
> > +     NCT6694_IRQ_GPIO6,
> > +     NCT6694_IRQ_GPIO7,
> > +     NCT6694_IRQ_GPIO8,
> > +     NCT6694_IRQ_GPIO9,
> > +     NCT6694_IRQ_GPIOA,
> > +     NCT6694_IRQ_GPIOB,
> > +     NCT6694_IRQ_GPIOC,
> > +     NCT6694_IRQ_GPIOD,
> > +     NCT6694_IRQ_GPIOE,
> > +     NCT6694_IRQ_GPIOF,
> > +     NCT6694_IRQ_CAN1,
> > +     NCT6694_IRQ_CAN2,
> > +     NCT6694_IRQ_RTC,
> > +     NCT6694_NR_IRQS,
> > +};
> > +
> > +enum nct6694_response_err_status {
> > +     NCT6694_NO_ERROR = 0,
> > +     NCT6694_FORMAT_ERROR,
> > +     NCT6694_RESERVED1,
> > +     NCT6694_RESERVED2,
> > +     NCT6694_NOT_SUPPORT_ERROR,
> > +     NCT6694_NO_RESPONSE_ERROR,
> > +     NCT6694_TIMEOUT_ERROR,
> > +     NCT6694_PENDING,
> > +};
> > +
> > +struct __packed nct6694_cmd_header {
> > +     u8 rsv1;
> > +     u8 mod;
> > +     union __packed {
> > +             __le16 offset;
> > +             struct __packed {
> > +                     u8 cmd;
> > +                     u8 sel;
> > +             };
> > +     };
> > +     u8 hctrl;
> > +     u8 rsv2;
> > +     __le16 len;
> > +};
> > +
> > +struct __packed nct6694_response_header {
> > +     u8 sequence_id;
> > +     u8 sts;
> > +     u8 reserved[4];
> > +     __le16 len;
> > +};
> > +
> > +union __packed nct6694_usb_msg {
> > +     struct nct6694_cmd_header cmd_header;
> > +     struct nct6694_response_header response_header;
> > +};
> > +
> > +struct nct6694 {
>
> Do all of these values need to be stored?
>

I think that's right.

> > +     struct usb_device *udev;
> > +     struct urb *int_in_urb;
> > +     struct irq_domain *domain;
> > +     struct mutex access_lock;
> > +     struct mutex irq_lock;
> > +     union nct6694_usb_msg *usb_msg;
> > +     unsigned char *int_buffer;
> > +     unsigned int irq_enable;
> > +     /* time in msec to wait for the urb to the complete */
>
> "Time"  "URB"

Fix it in the v6.

> > +     long timeout;
> > +};
> > +
> > +int nct6694_read_msg(struct nct6694 *nct6694, struct nct6694_cmd_header *cmd_hd,
> > +                  void *buf);
> > +
> > +int nct6694_write_msg(struct nct6694 *nct6694, struct nct6694_cmd_header *cmd_hd,
> > +                   void *buf);
> > +
> > +#endif
> > --
> > 2.34.1
> >
>

Best regards,
Ming
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index a87ddad78e26..79568f82b98a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16717,6 +16717,13 @@  F:	drivers/nubus/
 F:	include/linux/nubus.h
 F:	include/uapi/linux/nubus.h
 
+NUVOTON NCT6694 MFD DRIVER
+M:	Ming Yu <tmyu0@nuvoton.com>
+L:	linux-kernel@vger.kernel.org
+S:	Supported
+F:	drivers/mfd/nct6694.c
+F:	include/linux/mfd/nct6694.h
+
 NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
 M:	Antonino Daplas <adaplas@gmail.com>
 L:	linux-fbdev@vger.kernel.org
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index ae23b317a64e..3e641bfeeb38 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1045,6 +1045,16 @@  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 adds support for Nuvoton USB device NCT6694 sharing peripherals
+	  This includes the USB device driver and core APIs.
+	  Additional drivers must be enabled in order to use the functionality
+	  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 e057d6d6faef..3c902d3704dc 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..294b6b7a902e
--- /dev/null
+++ b/drivers/mfd/nct6694.c
@@ -0,0 +1,388 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 MFD driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#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>
+
+#define MFD_DEV_SIMPLE(_name)				\
+{							\
+	.name = NCT6694_DEV_##_name,			\
+}							\
+
+#define MFD_DEV_WITH_ID(_name, _id)			\
+{							\
+	.name = NCT6694_DEV_##_name,			\
+	.id = _id,					\
+}
+
+/* MFD device resources */
+static const struct mfd_cell nct6694_dev[] = {
+	MFD_DEV_WITH_ID(GPIO, 0x0),
+	MFD_DEV_WITH_ID(GPIO, 0x1),
+	MFD_DEV_WITH_ID(GPIO, 0x2),
+	MFD_DEV_WITH_ID(GPIO, 0x3),
+	MFD_DEV_WITH_ID(GPIO, 0x4),
+	MFD_DEV_WITH_ID(GPIO, 0x5),
+	MFD_DEV_WITH_ID(GPIO, 0x6),
+	MFD_DEV_WITH_ID(GPIO, 0x7),
+	MFD_DEV_WITH_ID(GPIO, 0x8),
+	MFD_DEV_WITH_ID(GPIO, 0x9),
+	MFD_DEV_WITH_ID(GPIO, 0xA),
+	MFD_DEV_WITH_ID(GPIO, 0xB),
+	MFD_DEV_WITH_ID(GPIO, 0xC),
+	MFD_DEV_WITH_ID(GPIO, 0xD),
+	MFD_DEV_WITH_ID(GPIO, 0xE),
+	MFD_DEV_WITH_ID(GPIO, 0xF),
+
+	MFD_DEV_WITH_ID(I2C, 0x0),
+	MFD_DEV_WITH_ID(I2C, 0x1),
+	MFD_DEV_WITH_ID(I2C, 0x2),
+	MFD_DEV_WITH_ID(I2C, 0x3),
+	MFD_DEV_WITH_ID(I2C, 0x4),
+	MFD_DEV_WITH_ID(I2C, 0x5),
+
+	MFD_DEV_WITH_ID(CAN, 0x0),
+	MFD_DEV_WITH_ID(CAN, 0x1),
+
+	MFD_DEV_WITH_ID(WDT, 0x0),
+	MFD_DEV_WITH_ID(WDT, 0x1),
+
+	MFD_DEV_SIMPLE(HWMON),
+	MFD_DEV_SIMPLE(RTC),
+};
+
+static int nct6694_response_err_handling(struct nct6694 *nct6694,
+					 unsigned char err_status)
+{
+	struct device *dev = &nct6694->udev->dev;
+
+	switch (err_status) {
+	case NCT6694_NO_ERROR:
+		return err_status;
+	case NCT6694_NOT_SUPPORT_ERROR:
+		dev_dbg(dev, "%s: Command is not supported!\n", __func__);
+		break;
+	case NCT6694_NO_RESPONSE_ERROR:
+		dev_dbg(dev, "%s: Command received no response!\n", __func__);
+		break;
+	case NCT6694_TIMEOUT_ERROR:
+		dev_dbg(dev, "%s: Command timed out!\n", __func__);
+		break;
+	case NCT6694_PENDING:
+		dev_dbg(dev, "%s: Command is pending!\n", __func__);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return -EIO;
+}
+
+int nct6694_read_msg(struct nct6694 *nct6694,
+		     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_GET;
+
+	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;
+
+	/* 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_dbg(&nct6694->udev->dev, "%s: Received length is not match!\n",
+			__func__);
+		return -EIO;
+	}
+
+	return nct6694_response_err_handling(nct6694, msg->response_header.sts);
+}
+EXPORT_SYMBOL(nct6694_read_msg);
+
+int nct6694_write_msg(struct nct6694 *nct6694, 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_dbg(&nct6694->udev->dev, "%s: Sent length is not match!\n",
+			__func__);
+		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;
+	struct device *dev = &nct6694->udev->dev;
+	unsigned int *int_status = urb->transfer_buffer;
+	int ret;
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+	default:
+		goto resubmit;
+	}
+
+	while (*int_status) {
+		int irq = __ffs(*int_status);
+
+		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(dev, "%s: Failed to resubmit urb, status %pe",
+			__func__, ERR_PTR(ret));
+}
+
+static void nct6694_irq_lock(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&nct6694->irq_lock);
+}
+
+static void nct6694_irq_sync_unlock(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+
+	mutex_unlock(&nct6694->irq_lock);
+}
+
+static void nct6694_irq_enable(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+	irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+	nct6694->irq_enable |= BIT(hwirq);
+}
+
+static void nct6694_irq_disable(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+	irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+	nct6694->irq_enable &= ~BIT(hwirq);
+}
+
+static struct irq_chip nct6694_irq_chip = {
+	.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_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				  irq_hw_number_t hw)
+{
+	struct nct6694 *nct6694 = d->host_data;
+
+	irq_set_chip_data(irq, nct6694);
+	irq_set_chip_and_handler(irq, &nct6694_irq_chip, handle_simple_irq);
+
+	return 0;
+}
+
+static void nct6694_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+}
+
+static const struct irq_domain_ops nct6694_irq_domain_ops = {
+	.map	= nct6694_irq_domain_map,
+	.unmap	= nct6694_irq_domain_unmap,
+};
+
+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 = &udev->dev;
+	struct nct6694 *nct6694;
+	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);
+
+	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->udev = udev;
+	nct6694->timeout = NCT6694_URB_TIMEOUT;	/* Wait until urb complete */
+
+	devm_mutex_init(dev, &nct6694->access_lock);
+	devm_mutex_init(dev, &nct6694->irq_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(dev, nct6694);
+	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 usb_device *udev = interface_to_usbdev(iface);
+	struct nct6694 *nct6694 = usb_get_intfdata(iface);
+
+	mfd_remove_devices(&udev->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)},
+	{}
+};
+MODULE_DEVICE_TABLE(usb, nct6694_ids);
+
+static struct usb_driver nct6694_usb_driver = {
+	.name	= "nct6694",
+	.id_table = nct6694_ids,
+	.probe = nct6694_usb_probe,
+	.disconnect = nct6694_usb_disconnect,
+};
+
+module_usb_driver(nct6694_usb_driver);
+
+MODULE_DESCRIPTION("USB-MFD driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
new file mode 100644
index 000000000000..67ca835589ad
--- /dev/null
+++ b/include/linux/mfd/nct6694.h
@@ -0,0 +1,109 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Nuvoton NCT6694 USB transaction and data structure.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#ifndef __MFD_NCT6694_H
+#define __MFD_NCT6694_H
+
+#define NCT6694_DEV_GPIO	"nct6694-gpio"
+#define NCT6694_DEV_I2C		"nct6694-i2c"
+#define NCT6694_DEV_CAN		"nct6694-can"
+#define NCT6694_DEV_WDT		"nct6694-wdt"
+#define NCT6694_DEV_HWMON	"nct6694-hwmon"
+#define NCT6694_DEV_RTC		"nct6694-rtc"
+
+#define NCT6694_VENDOR_ID	0x0416
+#define NCT6694_PRODUCT_ID	0x200B
+#define NCT6694_INT_IN_EP	0x81
+#define NCT6694_BULK_IN_EP	0x02
+#define NCT6694_BULK_OUT_EP	0x03
+
+#define NCT6694_HCTRL_SET	0x40
+#define NCT6694_HCTRL_GET	0x80
+
+#define NCT6694_URB_TIMEOUT	1000
+
+enum nct6694_irq_id {
+	NCT6694_IRQ_GPIO0 = 0,
+	NCT6694_IRQ_GPIO1,
+	NCT6694_IRQ_GPIO2,
+	NCT6694_IRQ_GPIO3,
+	NCT6694_IRQ_GPIO4,
+	NCT6694_IRQ_GPIO5,
+	NCT6694_IRQ_GPIO6,
+	NCT6694_IRQ_GPIO7,
+	NCT6694_IRQ_GPIO8,
+	NCT6694_IRQ_GPIO9,
+	NCT6694_IRQ_GPIOA,
+	NCT6694_IRQ_GPIOB,
+	NCT6694_IRQ_GPIOC,
+	NCT6694_IRQ_GPIOD,
+	NCT6694_IRQ_GPIOE,
+	NCT6694_IRQ_GPIOF,
+	NCT6694_IRQ_CAN1,
+	NCT6694_IRQ_CAN2,
+	NCT6694_IRQ_RTC,
+	NCT6694_NR_IRQS,
+};
+
+enum nct6694_response_err_status {
+	NCT6694_NO_ERROR = 0,
+	NCT6694_FORMAT_ERROR,
+	NCT6694_RESERVED1,
+	NCT6694_RESERVED2,
+	NCT6694_NOT_SUPPORT_ERROR,
+	NCT6694_NO_RESPONSE_ERROR,
+	NCT6694_TIMEOUT_ERROR,
+	NCT6694_PENDING,
+};
+
+struct __packed nct6694_cmd_header {
+	u8 rsv1;
+	u8 mod;
+	union __packed {
+		__le16 offset;
+		struct __packed {
+			u8 cmd;
+			u8 sel;
+		};
+	};
+	u8 hctrl;
+	u8 rsv2;
+	__le16 len;
+};
+
+struct __packed nct6694_response_header {
+	u8 sequence_id;
+	u8 sts;
+	u8 reserved[4];
+	__le16 len;
+};
+
+union __packed nct6694_usb_msg {
+	struct nct6694_cmd_header cmd_header;
+	struct nct6694_response_header response_header;
+};
+
+struct nct6694 {
+	struct usb_device *udev;
+	struct urb *int_in_urb;
+	struct irq_domain *domain;
+	struct mutex access_lock;
+	struct mutex irq_lock;
+	union nct6694_usb_msg *usb_msg;
+	unsigned char *int_buffer;
+	unsigned int irq_enable;
+	/* time in msec to wait for the urb to the complete */
+	long timeout;
+};
+
+int nct6694_read_msg(struct nct6694 *nct6694, struct nct6694_cmd_header *cmd_hd,
+		     void *buf);
+
+int nct6694_write_msg(struct nct6694 *nct6694, struct nct6694_cmd_header *cmd_hd,
+		      void *buf);
+
+#endif