From patchwork Tue Sep 19 10:38:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 13391151 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4CF19CD54B1 for ; Tue, 19 Sep 2023 10:38:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) id 37518C433CB; Tue, 19 Sep 2023 10:38:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 788A9C433CD; Tue, 19 Sep 2023 10:38:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695119914; bh=1FP7EheJHFdRKcOefqv+YBraqRuvIAyCgljheItg8G0=; h=From:List-Id:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gij6iSQTCF1pDPBFPv+8W7Mx1sc1wjUYsS+AWDBNO5CZ+1Sl1eiZh7ZY6dfIfXFTG nHgrpoDTa4A1Pej9uIkVEfJz6k74AC7tBE27RNdYskBI4VFZC7RzWqqlR/l3UfSkTd ruBzb8EBYlQdYIbUYxXb+ss+D6n1nIfIzI2v1wlOPgMzPlRP4io1uuulASlWILeQUE d/DeB1YKIAOkoQbAZ3GOoCwxW7C71sNeCzZHpXcAR1nMqrdrMqsOD8wPGbdx/aixZO q/OJypCIv7BEp9I9k+VwpzaeYTmnlTXNRYyteJKmuCRZyKCfSZxtkKpPSMJ+kkVM68 7B1iXdG4k512Q== From: =?utf-8?q?Marek_Beh=C3=BAn?= List-Id: To: Gregory CLEMENT , Arnd Bergmann , soc@kernel.org, arm@kernel.org, Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org Cc: =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH v2 5/7] platform: cznic: turris-omnia-mcu: Add support for MCU watchdog Date: Tue, 19 Sep 2023 12:38:13 +0200 Message-ID: <20230919103815.16818-6-kabel@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230919103815.16818-1-kabel@kernel.org> References: <20230919103815.16818-1-kabel@kernel.org> MIME-Version: 1.0 Add support for the watchdog mechanism provided by the MCU. Signed-off-by: Marek Behún --- drivers/platform/cznic/Kconfig | 2 + drivers/platform/cznic/Makefile | 1 + .../platform/cznic/turris-omnia-mcu-base.c | 4 + .../cznic/turris-omnia-mcu-watchdog.c | 126 ++++++++++++++++++ drivers/platform/cznic/turris-omnia-mcu.h | 24 ++++ 5 files changed, 157 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 6f1470d1f673..a43997a12d74 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-objs := turris-omnia-mcu-base.o turris-omnia-mcu-objs += turris-omnia-mcu-gpio.o turris-omnia-mcu-objs += turris-omnia-mcu-sys-off-wakeup.o +turris-omnia-mcu-objs += 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 b507f81ebe0a..708265203cc1 100644 --- a/drivers/platform/cznic/turris-omnia-mcu-base.c +++ b/drivers/platform/cznic/turris-omnia-mcu-base.c @@ -230,6 +230,10 @@ static int omnia_mcu_probe(struct i2c_client *client) if (ret) return ret; + ret = omnia_mcu_register_watchdog(mcu); + if (ret) + return ret; + return 0; } 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..2238b2167c45 --- /dev/null +++ b/drivers/platform/cznic/turris-omnia-mcu-watchdog.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CZ.NIC's Turris Omnia MCU watchdog driver + * + * 2023 by Marek Behún + */ + +#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); + + /* + * The MCU also implements LED controller, and the LED driver may in + * some cases require more I2C bandwidth. In order to prevent stealing + * that bandwidth from the LED driver, configure minimum time between + * pings to 10% of the configured timeout (for 120 second timeout we + * will be pinging at most every 12 seconds). + */ + mcu->wdt.min_hw_heartbeat_ms = 100 * mcu->wdt.timeout; + + 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) { + dev_err(dev, "Cannot get MCU watchdog state: %d\n", ret); + return ret; + } + + 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) + dev_err(dev, "Cannot register MCU watchdog: %d\n", ret); + + return ret; +} diff --git a/drivers/platform/cznic/turris-omnia-mcu.h b/drivers/platform/cznic/turris-omnia-mcu.h index c40ac07be5f5..89fe39f4255f 100644 --- a/drivers/platform/cznic/turris-omnia-mcu.h +++ b/drivers/platform/cznic/turris-omnia-mcu.h @@ -16,6 +16,7 @@ #include #include #include +#include #include struct omnia_mcu { @@ -36,6 +37,9 @@ struct omnia_mcu { struct rtc_device *rtcdev; u32 rtc_alarm; bool front_button_poweron; + + /* MCU watchdog */ + struct watchdog_device wdt; }; static inline int omnia_cmd_write(const struct i2c_client *client, void *cmd, @@ -46,6 +50,25 @@ static inline int omnia_cmd_write(const struct i2c_client *client, void *cmd, return ret < 0 ? ret : 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) { @@ -136,5 +159,6 @@ static inline int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd) int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu); void omnia_mcu_unregister_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 /* __DRIVERS_PLATFORM_CZNIC_TURRIS_OMNIA_MCU_H */