| Message ID | 20250207074502.1055111-1-a0282524688@gmail.com |
|---|---|
| Headers | show |
| Series | Add Nuvoton NCT6694 MFD drivers | expand |
Dear Christophe, Thank you for reviewing, Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午2:37寫道： > > Le 07/02/2025 à 08:44, 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. > > ... > > > +static struct irq_chip nct6694_irq_chip = { > > This could be const. > > (I'm working on a serie that should constify struct irq_chip, so this > one would already be done) > Okay, I will fix it in the next patch. Best regards, Ming
Dear Christophe, Thank you for reviewing, Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午3:06寫道： > > Le 07/02/2025 à 08:44, Ming Yu a écrit : > > This driver supports I2C adapter functionality for NCT6694 MFD > > device based on USB interface, each I2C controller use default > > baudrate(100K). > > ... > > > +static int nct6694_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > > +{ > > + struct nct6694_i2c_data *data = adap->algo_data; > > + struct nct6694_i2c_deliver *deliver = &data->deliver; > > + static const struct nct6694_cmd_header cmd_hd = { > > + .mod = NCT6694_I2C_MOD, > > + .cmd = NCT6694_I2C_DELIVER, > > + .sel = NCT6694_I2C_DELIVER_SEL, > > + .len = cpu_to_le16(sizeof(*deliver)) > > + }; > > + int ret, i; > > + > > + for (i = 0; i < num ; i++) { > > Tiny tiny nitpick: unneeded extra space after num > Okay, I will fix it in the next patch. Best regards, Ming
Dear Christophe, Thank you for reviewing, Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午4:30寫道： > > Le 07/02/2025 à 08:45, Ming Yu a écrit : > > This driver supports Watchdog timer functionality for NCT6694 MFD > > device based on USB interface. > > ... > > > +static int nct6694_wdt_probe(struct platform_device *pdev) > > +{ > > + const struct mfd_cell *cell = mfd_get_cell(pdev); > > + struct device *dev = &pdev->dev; > > + struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent); > > + struct nct6694_wdt_data *data; > > + struct watchdog_device *wdev; > > + > > + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); > > + if (!data) > > + return -ENOMEM; > > + > > + data->msg = devm_kzalloc(dev, sizeof(union nct6694_wdt_msg), > > + GFP_KERNEL); > > + if (!data->msg) > > + return -ENOMEM; > > + > > + data->dev = dev; > > + data->nct6694 = nct6694; > > + data->wdev_idx = cell->id; > > + > > + wdev = &data->wdev; > > + wdev->info = &nct6694_wdt_info; > > + wdev->ops = &nct6694_wdt_ops; > > + 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; > > + > > + devm_mutex_init(dev, &data->lock); > > Error handling? > (also apply for patch 1/7 and 6/7) > I will add error handling for these in the next patch. Best regards, Ming
On 07/02/2025 15:45:02+0800, Ming Yu wrote: > This driver supports RTC functionality for NCT6694 MFD device > based on USB interface. > > Signed-off-by: Ming Yu <a0282524688@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > MAINTAINERS | 1 + > drivers/rtc/Kconfig | 10 ++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-nct6694.c | 286 ++++++++++++++++++++++++++++++++++++++ > 4 files changed, 298 insertions(+) > create mode 100644 drivers/rtc/rtc-nct6694.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index a9eda4530b07..7eba4ffdc877 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -16927,6 +16927,7 @@ F: drivers/hwmon/nct6694-hwmon.c > F: drivers/i2c/busses/i2c-nct6694.c > F: drivers/mfd/nct6694.c > F: drivers/net/can/usb/nct6694_canfd.c > +F: drivers/rtc/rtc-nct6694.c > F: drivers/watchdog/nct6694_wdt.c > F: include/linux/mfd/nct6694.h > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 0bbbf778ecfa..248425bf26f3 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -416,6 +416,16 @@ config RTC_DRV_NCT3018Y > This driver can also be built as a module, if so, the module will be > called "rtc-nct3018y". > > +config RTC_DRV_NCT6694 > + tristate "Nuvoton NCT6694 RTC support" > + depends on MFD_NCT6694 > + help > + If you say yes to this option, support will be included for Nuvoton > + NCT6694, a USB device to RTC. > + > + This driver can also be built as a module. If so, the module will > + be called rtc-nct6694. > + > config RTC_DRV_RK808 > tristate "Rockchip RK805/RK808/RK809/RK817/RK818 RTC" > depends on MFD_RK8XX > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 489b4ab07068..d0d6f4a4972e 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -118,6 +118,7 @@ obj-$(CONFIG_RTC_DRV_MXC) += rtc-mxc.o > obj-$(CONFIG_RTC_DRV_MXC_V2) += rtc-mxc_v2.o > obj-$(CONFIG_RTC_DRV_GAMECUBE) += rtc-gamecube.o > obj-$(CONFIG_RTC_DRV_NCT3018Y) += rtc-nct3018y.o > +obj-$(CONFIG_RTC_DRV_NCT6694) += rtc-nct6694.o > obj-$(CONFIG_RTC_DRV_NTXEC) += rtc-ntxec.o > obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o > obj-$(CONFIG_RTC_DRV_OPAL) += rtc-opal.o > diff --git a/drivers/rtc/rtc-nct6694.c b/drivers/rtc/rtc-nct6694.c > new file mode 100644 > index 000000000000..892674d453d1 > --- /dev/null > +++ b/drivers/rtc/rtc-nct6694.c > @@ -0,0 +1,286 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Nuvoton NCT6694 RTC driver based on USB interface. > + * > + * Copyright (C) 2024 Nuvoton Technology Corp. > + */ > + > +#include <linux/bcd.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/platform_device.h> > +#include <linux/rtc.h> > +#include <linux/slab.h> > + > +/* > + * USB command module type for NCT6694 RTC controller. > + * This defines the module type used for communication with the NCT6694 > + * RTC controller over the USB interface. > + */ > +#define NCT6694_RTC_MOD 0x08 > + > +/* Command 00h - RTC Time */ > +#define NCT6694_RTC_TIME 0x0000 > +#define NCT6694_RTC_TIME_SEL 0x00 > + > +/* Command 01h - RTC Alarm */ > +#define NCT6694_RTC_ALARM 0x01 > +#define NCT6694_RTC_ALARM_SEL 0x00 > + > +/* Command 02h - RTC Status */ > +#define NCT6694_RTC_STATUS 0x02 > +#define NCT6694_RTC_STATUS_SEL 0x00 > + > +#define NCT6694_RTC_IRQ_INT_EN BIT(0) /* Transmit a USB INT-in when RTC alarm */ > +#define NCT6694_RTC_IRQ_GPO_EN BIT(5) /* Trigger a GPO Low Pulse when RTC alarm */ > + > +#define NCT6694_RTC_IRQ_EN (NCT6694_RTC_IRQ_INT_EN | NCT6694_RTC_IRQ_GPO_EN) > +#define NCT6694_RTC_IRQ_STS BIT(0) /* Write 1 clear IRQ status */ > + > +struct __packed nct6694_rtc_time { > + u8 sec; > + u8 min; > + u8 hour; > + u8 week; > + u8 day; > + u8 month; > + u8 year; > +}; > + > +struct __packed nct6694_rtc_alarm { > + u8 sec; > + u8 min; > + u8 hour; > + u8 alarm_en; > + u8 alarm_pend; > +}; > + > +struct __packed nct6694_rtc_status { > + u8 irq_en; > + u8 irq_pend; > +}; > + > +union __packed nct6694_rtc_msg { > + struct nct6694_rtc_time time; > + struct nct6694_rtc_alarm alarm; > + struct nct6694_rtc_status sts; > +}; > + > +struct nct6694_rtc_data { > + struct nct6694 *nct6694; > + struct rtc_device *rtc; > + union nct6694_rtc_msg *msg; > +}; > + > +static int nct6694_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > + struct nct6694_rtc_data *data = dev_get_drvdata(dev); > + struct nct6694_rtc_time *time = &data->msg->time; > + static const struct nct6694_cmd_header cmd_hd = { > + .mod = NCT6694_RTC_MOD, > + .cmd = NCT6694_RTC_TIME, > + .sel = NCT6694_RTC_TIME_SEL, > + .len = cpu_to_le16(sizeof(*time)) > + }; > + int ret; > + > + ret = nct6694_read_msg(data->nct6694, &cmd_hd, time); > + if (ret) > + return ret; > + > + tm->tm_sec = bcd2bin(time->sec); /* tm_sec expect 0 ~ 59 */ > + tm->tm_min = bcd2bin(time->min); /* tm_min expect 0 ~ 59 */ > + tm->tm_hour = bcd2bin(time->hour); /* tm_hour expect 0 ~ 23 */ > + tm->tm_wday = bcd2bin(time->week) - 1; /* tm_wday expect 0 ~ 6 */ > + tm->tm_mday = bcd2bin(time->day); /* tm_mday expect 1 ~ 31 */ > + tm->tm_mon = bcd2bin(time->month) - 1; /* tm_month expect 0 ~ 11 */ > + tm->tm_year = bcd2bin(time->year) + 100; /* tm_year expect since 1900 */ > + > + return ret; > +} > + > +static int nct6694_rtc_set_time(struct device *dev, struct rtc_time *tm) > +{ > + struct nct6694_rtc_data *data = dev_get_drvdata(dev); > + struct nct6694_rtc_time *time = &data->msg->time; > + static const struct nct6694_cmd_header cmd_hd = { > + .mod = NCT6694_RTC_MOD, > + .cmd = NCT6694_RTC_TIME, > + .sel = NCT6694_RTC_TIME_SEL, > + .len = cpu_to_le16(sizeof(*time)) > + }; > + > + time->sec = bin2bcd(tm->tm_sec); > + time->min = bin2bcd(tm->tm_min); > + time->hour = bin2bcd(tm->tm_hour); > + time->week = bin2bcd(tm->tm_wday + 1); > + time->day = bin2bcd(tm->tm_mday); > + time->month = bin2bcd(tm->tm_mon + 1); > + time->year = bin2bcd(tm->tm_year - 100); > + > + return nct6694_write_msg(data->nct6694, &cmd_hd, time); > +} > + > +static int nct6694_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) > +{ > + struct nct6694_rtc_data *data = dev_get_drvdata(dev); > + struct nct6694_rtc_alarm *alarm = &data->msg->alarm; > + static const struct nct6694_cmd_header cmd_hd = { > + .mod = NCT6694_RTC_MOD, > + .cmd = NCT6694_RTC_ALARM, > + .sel = NCT6694_RTC_ALARM_SEL, > + .len = cpu_to_le16(sizeof(*alarm)) > + }; > + int ret; > + > + ret = nct6694_read_msg(data->nct6694, &cmd_hd, alarm); > + if (ret) > + return ret; > + > + alrm->time.tm_sec = bcd2bin(alarm->sec); > + alrm->time.tm_min = bcd2bin(alarm->min); > + alrm->time.tm_hour = bcd2bin(alarm->hour); > + alrm->enabled = alarm->alarm_en; > + alrm->pending = alarm->alarm_pend; > + > + return ret; > +} > + > +static int nct6694_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) > +{ > + struct nct6694_rtc_data *data = dev_get_drvdata(dev); > + struct nct6694_rtc_alarm *alarm = &data->msg->alarm; > + static const struct nct6694_cmd_header cmd_hd = { > + .mod = NCT6694_RTC_MOD, > + .cmd = NCT6694_RTC_ALARM, > + .sel = NCT6694_RTC_ALARM_SEL, > + .len = cpu_to_le16(sizeof(*alarm)) > + }; > + > + alarm->sec = bin2bcd(alrm->time.tm_sec); > + alarm->min = bin2bcd(alrm->time.tm_min); > + alarm->hour = bin2bcd(alrm->time.tm_hour); > + alarm->alarm_en = alrm->enabled ? NCT6694_RTC_IRQ_EN : 0; > + alarm->alarm_pend = 0; > + > + return nct6694_write_msg(data->nct6694, &cmd_hd, alarm); > +} > + > +static int nct6694_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) > +{ > + struct nct6694_rtc_data *data = dev_get_drvdata(dev); > + struct nct6694_rtc_status *sts = &data->msg->sts; > + static const struct nct6694_cmd_header cmd_hd = { > + .mod = NCT6694_RTC_MOD, > + .cmd = NCT6694_RTC_STATUS, > + .sel = NCT6694_RTC_STATUS_SEL, > + .len = cpu_to_le16(sizeof(*sts)) > + }; > + > + if (enabled) > + sts->irq_en |= NCT6694_RTC_IRQ_EN; > + else > + sts->irq_en &= ~NCT6694_RTC_IRQ_EN; > + > + sts->irq_pend = 0; > + > + return nct6694_write_msg(data->nct6694, &cmd_hd, sts); > +} > + > +static const struct rtc_class_ops nct6694_rtc_ops = { > + .read_time = nct6694_rtc_read_time, > + .set_time = nct6694_rtc_set_time, > + .read_alarm = nct6694_rtc_read_alarm, > + .set_alarm = nct6694_rtc_set_alarm, > + .alarm_irq_enable = nct6694_rtc_alarm_irq_enable, > +}; > + > +static irqreturn_t nct6694_irq(int irq, void *dev_id) > +{ > + struct nct6694_rtc_data *data = dev_id; > + struct nct6694_rtc_status *sts = &data->msg->sts; > + static const struct nct6694_cmd_header cmd_hd = { > + .mod = NCT6694_RTC_MOD, > + .cmd = NCT6694_RTC_STATUS, > + .sel = NCT6694_RTC_STATUS_SEL, > + .len = cpu_to_le16(sizeof(*sts)) > + }; > + int ret; > + > + rtc_lock(data->rtc); > + > + sts->irq_en = NCT6694_RTC_IRQ_EN; > + sts->irq_pend = NCT6694_RTC_IRQ_STS; > + ret = nct6694_write_msg(data->nct6694, &cmd_hd, sts); > + if (ret) { > + rtc_unlock(data->rtc); > + return IRQ_NONE; > + } > + > + rtc_update_irq(data->rtc, 1, RTC_IRQF | RTC_AF); > + > + rtc_unlock(data->rtc); > + > + return IRQ_HANDLED; > +} > + > +static int nct6694_rtc_probe(struct platform_device *pdev) > +{ > + struct nct6694_rtc_data *data; > + struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent); > + int ret, irq; > + > + irq = irq_create_mapping(nct6694->domain, NCT6694_IRQ_RTC); > + if (!irq) > + return -EINVAL; > + > + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->msg = devm_kzalloc(&pdev->dev, sizeof(union nct6694_rtc_msg), > + GFP_KERNEL); > + if (!data->msg) > + return -ENOMEM; > + > + data->rtc = devm_rtc_allocate_device(&pdev->dev); > + if (IS_ERR(data->rtc)) > + return PTR_ERR(data->rtc); > + > + data->nct6694 = nct6694; > + data->rtc->ops = &nct6694_rtc_ops; > + data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; > + data->rtc->range_max = RTC_TIMESTAMP_END_2099; > + > + platform_set_drvdata(pdev, data); > + > + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, > + nct6694_irq, IRQF_ONESHOT, > + "rtc-nct6694", data); > + if (ret < 0) > + return dev_err_probe(&pdev->dev, ret, "Failed to request irq\n"); > + > + ret = devm_rtc_register_device(data->rtc); > + if (ret) > + return ret; > + > + device_init_wakeup(&pdev->dev, true); > + return 0; > +} > + > +static struct platform_driver nct6694_rtc_driver = { > + .driver = { > + .name = "rtc-nct6694", > + }, > + .probe = nct6694_rtc_probe, > +}; > + > +module_platform_driver(nct6694_rtc_driver); > + > +MODULE_DESCRIPTION("USB-RTC driver for NCT6694"); > +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("platform:nct6694-rtc"); > -- > 2.34.1 >
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 6: - Fix nct6694_can_handle_state_change() in nct6694_canfd.c - Fix warnings in nct6694_canfd.c - Move the nct6694_can_priv's bec to the end in nct6694_canfd.c - Fix warning in nct6694_wdt.c - Fix temp_hyst's data type to signed variable in nct6694-hwmon.c Changes since version 5: - Modify the module name and the driver name consistently - Fix mfd_cell to MFD_CELL_NAME() and MFD_CELL_BASIC() - Drop unnecessary macros in nct6694.c - Update private data and drop mutex in nct6694_canfd.c - Fix nct6694_can_handle_state_change() in nct6694_canfd.c Changes since version 4: - Modify arguments in read/write function to a pointer to cmd_header - Modify all callers that call the read/write function - Move the nct6694_canfd.c to drivers/net/can/usb/ - Fix the missing rx offload function in nct6694_canfd.c - Fix warngings in nct6694-hwmon.c Changes since version 3: - Modify array buffer to structure for each drivers - Fix defines and comments for each drivers - Add header <linux/bits.h> and use BIT macro in nct6694.c and gpio-nct6694.c - Modify mutex_init() to devm_mutex_init() - Add rx-offload helper in nct6694_canfd.c - Drop watchdog_init_timeout() in nct6694_wdt.c - Modify the division method to DIV_ROUND_CLOSEST() in nct6694-hwmon.c - Drop private mutex and use rtc core lock in rtc-nct6694.c - Modify device_set_wakeup_capable() to device_init_wakeup() in rtc-nct6694.c 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 CANFD 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 | 458 ++++++++++++++ drivers/hwmon/Kconfig | 10 + drivers/hwmon/Makefile | 1 + drivers/hwmon/nct6694-hwmon.c | 947 ++++++++++++++++++++++++++++ drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-nct6694.c | 152 +++++ drivers/mfd/Kconfig | 18 + drivers/mfd/Makefile | 2 + drivers/mfd/nct6694.c | 373 +++++++++++ drivers/net/can/usb/Kconfig | 11 + drivers/net/can/usb/Makefile | 1 + drivers/net/can/usb/nct6694_canfd.c | 809 ++++++++++++++++++++++++ drivers/rtc/Kconfig | 10 + drivers/rtc/Makefile | 1 + drivers/rtc/rtc-nct6694.c | 286 +++++++++ drivers/watchdog/Kconfig | 11 + drivers/watchdog/Makefile | 1 + drivers/watchdog/nct6694_wdt.c | 295 +++++++++ include/linux/mfd/nct6694.h | 102 +++ 23 files changed, 3525 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/usb/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