From 33ae4e4c86bc6ff298489fb8b743e2743dd0af6d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= Date: Mon, 1 Jul 2024 13:30:07 +0200 Subject: [PATCH 05/11] platform: cznic: turris-omnia-mcu: Add support for MCU watchdog MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add support for the watchdog mechanism provided by the MCU. Signed-off-by: Marek Behún Reviewed-by: Andy Shevchenko Reviewed-by: Guenter Roeck Acked-by: Bartosz Golaszewski Link: https://lore.kernel.org/r/20240701113010.16447-6-kabel@kernel.org Signed-off-by: Arnd Bergmann --- drivers/platform/cznic/Kconfig | 2 + drivers/platform/cznic/Makefile | 1 + .../platform/cznic/turris-omnia-mcu-base.c | 4 + .../cznic/turris-omnia-mcu-watchdog.c | 130 ++++++++++++++++++ drivers/platform/cznic/turris-omnia-mcu.h | 24 ++++ 5 files changed, 161 insertions(+) create mode 100644 drivers/platform/cznic/turris-omnia-mcu-watchdog.c --- a/drivers/platform/cznic/Kconfig +++ b/drivers/platform/cznic/Kconfig @@ -19,6 +19,7 @@ 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. @@ -26,6 +27,7 @@ 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 --- a/drivers/platform/cznic/Makefile +++ b/drivers/platform/cznic/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_TURRIS_OMNIA_MCU) += turris 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 --- a/drivers/platform/cznic/turris-omnia-mcu-base.c +++ b/drivers/platform/cznic/turris-omnia-mcu-base.c @@ -376,6 +376,10 @@ static int omnia_mcu_probe(struct i2c_cl if (err) return err; + err = omnia_mcu_register_watchdog(mcu); + if (err) + return err; + return omnia_mcu_register_gpiochip(mcu); } --- /dev/null +++ b/drivers/platform/cznic/turris-omnia-mcu-watchdog.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CZ.NIC's Turris Omnia MCU watchdog driver + * + * 2024 by Marek Behún + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#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, OMNIA_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, OMNIA_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, OMNIA_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, OMNIA_CMD_SET_WDT_TIMEOUT, + timeout * DECI); +} + +static unsigned int omnia_wdt_get_timeleft(struct watchdog_device *wdt) +{ + struct omnia_mcu *mcu = watchdog_get_drvdata(wdt); + u16 timeleft; + int err; + + err = omnia_cmd_read_u16(mcu->client, OMNIA_CMD_GET_WDT_TIMELEFT, + &timeleft); + if (err) { + dev_err(&mcu->client->dev, "Cannot get watchdog timeleft: %d\n", + err); + return 0; + } + + return timeleft / DECI; +} + +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; + u8 state; + int err; + + if (!(mcu->features & OMNIA_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 = 65535 / DECI; + + 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); + + err = omnia_cmd_read_u8(mcu->client, OMNIA_CMD_GET_WATCHDOG_STATE, + &state); + if (err) + return dev_err_probe(dev, err, + "Cannot get MCU watchdog state\n"); + + if (state) + set_bit(WDOG_HW_RUNNING, &mcu->wdt.status); + + watchdog_set_nowayout(&mcu->wdt, nowayout); + watchdog_stop_on_reboot(&mcu->wdt); + err = devm_watchdog_register_device(dev, &mcu->wdt); + if (err) + return dev_err_probe(dev, err, + "Cannot register MCU watchdog\n"); + + return 0; +} --- a/drivers/platform/cznic/turris-omnia-mcu.h +++ b/drivers/platform/cznic/turris-omnia-mcu.h @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -43,6 +44,9 @@ 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, @@ -55,6 +59,25 @@ static inline int omnia_cmd_write(const 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) { @@ -158,5 +181,6 @@ extern const struct attribute_group omni 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 */