On Thu, Apr 18, 2024 at 02:11:10PM +0200, Marek Behún wrote:
> Add support for the watchdog mechanism provided by the MCU.
>
> Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
This driver should reside in driver/watchdog and use a generic API
such as regmap to access chip registers.
Guenter
> ---
> drivers/platform/cznic/Kconfig | 2 +
> drivers/platform/cznic/Makefile | 1 +
> .../platform/cznic/turris-omnia-mcu-base.c | 4 +
> .../cznic/turris-omnia-mcu-watchdog.c | 123 ++++++++++++++++++
> drivers/platform/cznic/turris-omnia-mcu.h | 24 ++++
> 5 files changed, 154 insertions(+)
> create mode 100644 drivers/platform/cznic/turris-omnia-mcu-watchdog.c
>
> diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
> index 0a752aa654fa..e2649cdecc38 100644
> --- a/drivers/platform/cznic/Kconfig
> +++ b/drivers/platform/cznic/Kconfig
> @@ -20,6 +20,7 @@ config TURRIS_OMNIA_MCU
> select GPIOLIB
> select GPIOLIB_IRQCHIP
> select RTC_CLASS
> + select WATCHDOG_CORE
> help
> Say Y here to add support for the features implemented by the
> microcontroller on the CZ.NIC's Turris Omnia SOHO router.
> @@ -27,6 +28,7 @@ config TURRIS_OMNIA_MCU
> - board poweroff into true low power mode (with voltage regulators
> disabled) and the ability to configure wake up from this mode (via
> rtcwake)
> + - MCU watchdog
> - GPIO pins
> - to get front button press events (the front button can be
> configured either to generate press events to the CPU or to change
> diff --git a/drivers/platform/cznic/Makefile b/drivers/platform/cznic/Makefile
> index a185ef882e44..687f7718c0a1 100644
> --- a/drivers/platform/cznic/Makefile
> +++ b/drivers/platform/cznic/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_TURRIS_OMNIA_MCU) += turris-omnia-mcu.o
> turris-omnia-mcu-y := turris-omnia-mcu-base.o
> turris-omnia-mcu-y += turris-omnia-mcu-gpio.o
> turris-omnia-mcu-y += turris-omnia-mcu-sys-off-wakeup.o
> +turris-omnia-mcu-y += turris-omnia-mcu-watchdog.o
> diff --git a/drivers/platform/cznic/turris-omnia-mcu-base.c b/drivers/platform/cznic/turris-omnia-mcu-base.c
> index 697ace090bda..5f88119d825c 100644
> --- a/drivers/platform/cznic/turris-omnia-mcu-base.c
> +++ b/drivers/platform/cznic/turris-omnia-mcu-base.c
> @@ -365,6 +365,10 @@ static int omnia_mcu_probe(struct i2c_client *client)
> if (err)
> return err;
>
> + err = omnia_mcu_register_watchdog(mcu);
> + if (err)
> + return err;
> +
> return omnia_mcu_register_gpiochip(mcu);
> }
>
> diff --git a/drivers/platform/cznic/turris-omnia-mcu-watchdog.c b/drivers/platform/cznic/turris-omnia-mcu-watchdog.c
> new file mode 100644
> index 000000000000..b0de9585da84
> --- /dev/null
> +++ b/drivers/platform/cznic/turris-omnia-mcu-watchdog.c
> @@ -0,0 +1,123 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * CZ.NIC's Turris Omnia MCU watchdog driver
> + *
> + * 2024 by Marek Behún <kabel@xxxxxxxxxx>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/moduleparam.h>
> +#include <linux/turris-omnia-mcu-interface.h>
> +#include <linux/types.h>
> +#include <linux/watchdog.h>
> +
> +#include "turris-omnia-mcu.h"
> +
> +#define WATCHDOG_TIMEOUT 120
> +
> +static unsigned int timeout;
> +module_param(timeout, int, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +static int omnia_wdt_start(struct watchdog_device *wdt)
> +{
> + struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
> +
> + return omnia_cmd_write_u8(mcu->client, CMD_SET_WATCHDOG_STATE, 1);
> +}
> +
> +static int omnia_wdt_stop(struct watchdog_device *wdt)
> +{
> + struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
> +
> + return omnia_cmd_write_u8(mcu->client, CMD_SET_WATCHDOG_STATE, 0);
> +}
> +
> +static int omnia_wdt_ping(struct watchdog_device *wdt)
> +{
> + struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
> +
> + return omnia_cmd_write_u8(mcu->client, CMD_SET_WATCHDOG_STATE, 1);
> +}
> +
> +static int omnia_wdt_set_timeout(struct watchdog_device *wdt,
> + unsigned int timeout)
> +{
> + struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
> +
> + return omnia_cmd_write_u16(mcu->client, CMD_SET_WDT_TIMEOUT,
> + timeout * 10);
> +}
> +
> +static unsigned int omnia_wdt_get_timeleft(struct watchdog_device *wdt)
> +{
> + struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
> + int ret;
> +
> + ret = omnia_cmd_read_u16(mcu->client, CMD_GET_WDT_TIMELEFT);
> + if (ret < 0) {
> + dev_err(&mcu->client->dev, "Cannot get watchdog timeleft: %d\n",
> + ret);
> + return 0;
> + }
> +
> + return ret / 10;
> +}
> +
> +static const struct watchdog_info omnia_wdt_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> + .identity = "Turris Omnia MCU Watchdog",
> +};
> +
> +static const struct watchdog_ops omnia_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = omnia_wdt_start,
> + .stop = omnia_wdt_stop,
> + .ping = omnia_wdt_ping,
> + .set_timeout = omnia_wdt_set_timeout,
> + .get_timeleft = omnia_wdt_get_timeleft,
> +};
> +
> +int omnia_mcu_register_watchdog(struct omnia_mcu *mcu)
> +{
> + struct device *dev = &mcu->client->dev;
> + int ret;
> +
> + if (!(mcu->features & FEAT_WDT_PING))
> + return 0;
> +
> + mcu->wdt.info = &omnia_wdt_info;
> + mcu->wdt.ops = &omnia_wdt_ops;
> + mcu->wdt.parent = dev;
> + mcu->wdt.min_timeout = 1;
> + mcu->wdt.max_timeout = 6553; /* 65535 deciseconds */
> +
> + mcu->wdt.timeout = WATCHDOG_TIMEOUT;
> + watchdog_init_timeout(&mcu->wdt, timeout, dev);
> +
> + watchdog_set_drvdata(&mcu->wdt, mcu);
> +
> + omnia_wdt_set_timeout(&mcu->wdt, mcu->wdt.timeout);
> +
> + ret = omnia_cmd_read_u8(mcu->client, CMD_GET_WATCHDOG_STATE);
> + if (ret < 0)
> + return dev_err_probe(dev, ret,
> + "Cannot get MCU watchdog state\n");
> +
> + if (ret)
> + set_bit(WDOG_HW_RUNNING, &mcu->wdt.status);
> +
> + watchdog_set_nowayout(&mcu->wdt, nowayout);
> + watchdog_stop_on_reboot(&mcu->wdt);
> + ret = devm_watchdog_register_device(dev, &mcu->wdt);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "Cannot register MCU watchdog\n");
> +
> + return 0;
> +}
> diff --git a/drivers/platform/cznic/turris-omnia-mcu.h b/drivers/platform/cznic/turris-omnia-mcu.h
> index 6179a4f2069e..1838cb3d636e 100644
> --- a/drivers/platform/cznic/turris-omnia-mcu.h
> +++ b/drivers/platform/cznic/turris-omnia-mcu.h
> @@ -14,6 +14,7 @@
> #include <linux/mutex.h>
> #include <linux/rtc.h>
> #include <linux/types.h>
> +#include <linux/watchdog.h>
> #include <linux/workqueue.h>
> #include <asm/byteorder.h>
> #include <asm/unaligned.h>
> @@ -41,6 +42,9 @@ struct omnia_mcu {
> struct rtc_device *rtcdev;
> u32 rtc_alarm;
> bool front_button_poweron;
> +
> + /* MCU watchdog */
> + struct watchdog_device wdt;
> };
>
> int omnia_cmd_write_read(const struct i2c_client *client,
> @@ -53,6 +57,25 @@ static inline int omnia_cmd_write(const struct i2c_client *client, void *cmd,
> return omnia_cmd_write_read(client, cmd, len, NULL, 0);
> }
>
> +static inline int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd,
> + u8 val)
> +{
> + u8 buf[2] = { cmd, val };
> +
> + return omnia_cmd_write(client, buf, sizeof(buf));
> +}
> +
> +static inline int omnia_cmd_write_u16(const struct i2c_client *client, u8 cmd,
> + u16 val)
> +{
> + u8 buf[3];
> +
> + buf[0] = cmd;
> + put_unaligned_le16(val, &buf[1]);
> +
> + return omnia_cmd_write(client, buf, sizeof(buf));
> +}
> +
> static inline int omnia_cmd_write_u32(const struct i2c_client *client, u8 cmd,
> u32 val)
> {
> @@ -129,5 +152,6 @@ extern const struct attribute_group omnia_mcu_poweroff_group;
>
> int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu);
> int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu);
> +int omnia_mcu_register_watchdog(struct omnia_mcu *mcu);
>
> #endif /* __TURRIS_OMNIA_MCU_H */
> --
> 2.43.2
>
>
