ab89fb5fb9
Add support for the watchdog mechanism provided by the MCU. Signed-off-by: Marek Behún <kabel@kernel.org> Reviewed-by: Andy Shevchenko <andy@kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Link: https://lore.kernel.org/r/20240701113010.16447-6-kabel@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
131 lines
3.2 KiB
C
131 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* CZ.NIC's Turris Omnia MCU watchdog driver
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*
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* 2024 by Marek Behún <kabel@kernel.org>
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*/
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#include <linux/bitops.h>
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#include <linux/device.h>
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#include <linux/i2c.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/units.h>
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#include <linux/watchdog.h>
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#include <linux/turris-omnia-mcu-interface.h>
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#include "turris-omnia-mcu.h"
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#define WATCHDOG_TIMEOUT 120
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static unsigned int timeout;
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static int omnia_wdt_start(struct watchdog_device *wdt)
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{
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struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
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return omnia_cmd_write_u8(mcu->client, OMNIA_CMD_SET_WATCHDOG_STATE, 1);
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}
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static int omnia_wdt_stop(struct watchdog_device *wdt)
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{
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struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
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return omnia_cmd_write_u8(mcu->client, OMNIA_CMD_SET_WATCHDOG_STATE, 0);
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}
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static int omnia_wdt_ping(struct watchdog_device *wdt)
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{
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struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
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return omnia_cmd_write_u8(mcu->client, OMNIA_CMD_SET_WATCHDOG_STATE, 1);
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}
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static int omnia_wdt_set_timeout(struct watchdog_device *wdt,
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unsigned int timeout)
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{
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struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
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return omnia_cmd_write_u16(mcu->client, OMNIA_CMD_SET_WDT_TIMEOUT,
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timeout * DECI);
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}
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static unsigned int omnia_wdt_get_timeleft(struct watchdog_device *wdt)
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{
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struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);
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u16 timeleft;
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int err;
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err = omnia_cmd_read_u16(mcu->client, OMNIA_CMD_GET_WDT_TIMELEFT,
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&timeleft);
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if (err) {
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dev_err(&mcu->client->dev, "Cannot get watchdog timeleft: %d\n",
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err);
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return 0;
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}
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return timeleft / DECI;
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}
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static const struct watchdog_info omnia_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "Turris Omnia MCU Watchdog",
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};
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static const struct watchdog_ops omnia_wdt_ops = {
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.owner = THIS_MODULE,
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.start = omnia_wdt_start,
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.stop = omnia_wdt_stop,
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.ping = omnia_wdt_ping,
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.set_timeout = omnia_wdt_set_timeout,
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.get_timeleft = omnia_wdt_get_timeleft,
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};
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int omnia_mcu_register_watchdog(struct omnia_mcu *mcu)
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{
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struct device *dev = &mcu->client->dev;
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u8 state;
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int err;
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if (!(mcu->features & OMNIA_FEAT_WDT_PING))
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return 0;
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mcu->wdt.info = &omnia_wdt_info;
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mcu->wdt.ops = &omnia_wdt_ops;
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mcu->wdt.parent = dev;
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mcu->wdt.min_timeout = 1;
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mcu->wdt.max_timeout = 65535 / DECI;
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mcu->wdt.timeout = WATCHDOG_TIMEOUT;
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watchdog_init_timeout(&mcu->wdt, timeout, dev);
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watchdog_set_drvdata(&mcu->wdt, mcu);
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omnia_wdt_set_timeout(&mcu->wdt, mcu->wdt.timeout);
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err = omnia_cmd_read_u8(mcu->client, OMNIA_CMD_GET_WATCHDOG_STATE,
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&state);
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if (err)
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return dev_err_probe(dev, err,
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"Cannot get MCU watchdog state\n");
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if (state)
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set_bit(WDOG_HW_RUNNING, &mcu->wdt.status);
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watchdog_set_nowayout(&mcu->wdt, nowayout);
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watchdog_stop_on_reboot(&mcu->wdt);
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err = devm_watchdog_register_device(dev, &mcu->wdt);
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if (err)
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return dev_err_probe(dev, err,
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"Cannot register MCU watchdog\n");
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return 0;
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}
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