[v3,0/7] Add Nuvoton NCT6694 MFD drivers

This patch series introduces support for Nuvoton NCT6694, a peripheral
expander based on USB interface. It models the chip as an MFD driver
(1/7), GPIO driver(2/7), I2C Adapter driver(3/7), CANfd driver(4/7),
WDT driver(5/7), HWMON driver(6/7), and RTC driver(7/7).

The MFD driver implements USB device functionality to issue
custom-define USB bulk pipe packets for NCT6694. 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.

The following introduces the custom-define USB transactions:
	nct6694_read_msg - Send bulk-out pipe to write request packet
			   Receive bulk-in pipe to read response packet
			   Receive bulk-in pipe to read data packet

	nct6694_write_msg - Send bulk-out pipe to write request packet
			    Send bulk-out pipe to write data packet
			    Receive bulk-in pipe to read response packet
			    Receive bulk-in pipe to read data packet

Changes since version 2:
- Add MODULE_ALIAS() for each child driver
- Modify gpio line names be a local variable in gpio-nct6694.c
- Drop unnecessary platform_get_drvdata() in gpio-nct6694.c
- Rename each command in nct6694_canfd.c
- Modify each function name consistently in nct6694_canfd.c
- Modify the pretimeout validation procedure in nct6694_wdt.c
- Fix warnings in nct6694-hwmon.c

Changes since version 1:
- Implement IRQ domain to handle IRQ demux in nct6694.c
- Modify USB_DEVICE to USB_DEVICE_AND_INTERFACE_INFO API in nct6694.c
- Add each driver's command structure
- Fix USB functions in nct6694.c
- Fix platform driver registration in each child driver
- Sort each driver's header files alphabetically
- Drop unnecessary header in gpio-nct6694.c
- Add gpio line names in gpio-nct6694.c
- Fix errors and warnings in nct6694_canfd.c
- Fix TX-flow control in nct6694_canfd.c
- Fix warnings in nct6694_wdt.c
- Drop unnecessary logs in nct6694_wdt.c
- Modify start() function to setup device in nct6694_wdt.c
- Add voltage sensors functionality in nct6694-hwmon.c
- Add temperature sensors functionality in nct6694-hwmon.c
- Fix overwrite error return values in nct6694-hwmon.c
- Add write value limitation for each write() function in nct6694-hwmon.c
- Drop unnecessary logs in rtc-nct6694.c
- Fix overwrite error return values in rtc-nct6694.c
- Modify to use dev_err_probe API in rtc-nct6694.c

Ming Yu (7):
  mfd: Add core driver for Nuvoton NCT6694
  gpio: Add Nuvoton NCT6694 GPIO support
  i2c: Add Nuvoton NCT6694 I2C support
  can: Add Nuvoton NCT6694 CAN support
  watchdog: Add Nuvoton NCT6694 WDT support
  hwmon: Add Nuvoton NCT6694 HWMON support
  rtc: Add Nuvoton NCT6694 RTC support

 MAINTAINERS                      |  13 +
 drivers/gpio/Kconfig             |  12 +
 drivers/gpio/Makefile            |   1 +
 drivers/gpio/gpio-nct6694.c      | 438 +++++++++++++++
 drivers/hwmon/Kconfig            |  10 +
 drivers/hwmon/Makefile           |   1 +
 drivers/hwmon/nct6694-hwmon.c    | 768 ++++++++++++++++++++++++++
 drivers/i2c/busses/Kconfig       |  10 +
 drivers/i2c/busses/Makefile      |   1 +
 drivers/i2c/busses/i2c-nct6694.c | 153 +++++
 drivers/mfd/Kconfig              |  10 +
 drivers/mfd/Makefile             |   2 +
 drivers/mfd/nct6694.c            | 382 +++++++++++++
 drivers/net/can/Kconfig          |  10 +
 drivers/net/can/Makefile         |   1 +
 drivers/net/can/nct6694_canfd.c  | 920 +++++++++++++++++++++++++++++++
 drivers/rtc/Kconfig              |  10 +
 drivers/rtc/Makefile             |   1 +
 drivers/rtc/rtc-nct6694.c        | 264 +++++++++
 drivers/watchdog/Kconfig         |  11 +
 drivers/watchdog/Makefile        |   1 +
 drivers/watchdog/nct6694_wdt.c   | 277 ++++++++++
 include/linux/mfd/nct6694.h      | 139 +++++
 23 files changed, 3435 insertions(+)
 create mode 100644 drivers/gpio/gpio-nct6694.c
 create mode 100644 drivers/hwmon/nct6694-hwmon.c
 create mode 100644 drivers/i2c/busses/i2c-nct6694.c
 create mode 100644 drivers/mfd/nct6694.c
 create mode 100644 drivers/net/can/nct6694_canfd.c
 create mode 100644 drivers/rtc/rtc-nct6694.c
 create mode 100644 drivers/watchdog/nct6694_wdt.c
 create mode 100644 include/linux/mfd/nct6694.h

On 12/10/24 02:45, Ming Yu wrote:
> This driver supports Watchdog timer functionality for NCT6694 MFD
> device based on USB interface.
> 
> Signed-off-by: Ming Yu <tmyu0@nuvoton.com>
> ---
...
> +static int nct6694_wdt_probe(struct platform_device *pdev)
> +{
...
> +	wdev->timeout = timeout;
> +	wdev->pretimeout = pretimeout;
> +	if (timeout < pretimeout) {
> +		dev_warn(data->dev, "pretimeout < timeout. Setting to zero\n");
> +		wdev->pretimeout = 0;
> +	}
> +
> +	wdev->min_timeout = 1;
> +	wdev->max_timeout = 255;
> +
> +	mutex_init(&data->lock);
> +
> +	platform_set_drvdata(pdev, data);
> +
> +	/* Register watchdog timer device to WDT framework */
> +	watchdog_set_drvdata(&data->wdev, data);
> +	watchdog_init_timeout(&data->wdev, timeout, dev);

This is pointless since timeout is pre-initialized with a value != 0.
That means a value provided through devicetree will never be used
unless the user sets timeout=0 as module parameter. But then the above
check for pretimeout is useless.

Guenter

On Tue, 10 Dec 2024 11:57:41 +0100 Mateusz Polchlopek wrote:
> > +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;  
> 
> RCT violation

This code is not under net not drivers/net
As a general rule please focus on functional review, formatting and
process issues are harder to judge unless you read all of the mailing
list traffic.

On 12/11/2024 2:56 AM, Jakub Kicinski wrote:
> On Tue, 10 Dec 2024 11:57:41 +0100 Mateusz Polchlopek wrote:
>>> +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;
>>
>> RCT violation
> 
> This code is not under net not drivers/net
> As a general rule please focus on functional review, formatting and
> process issues are harder to judge unless you read all of the mailing
> list traffic.

Okay, my bad. Thanks Kuba for explanation and I will focus on code next
time