diff options
Diffstat (limited to 'drivers/platform/cznic/turris-omnia-mcu-watchdog.c')
| -rw-r--r-- | drivers/platform/cznic/turris-omnia-mcu-watchdog.c | 130 |
1 files changed, 130 insertions, 0 deletions
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..3ad146ec1d80 --- /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 <kabel@kernel.org> + */ + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/units.h> +#include <linux/watchdog.h> + +#include <linux/turris-omnia-mcu-interface.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, 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; +} |