diff options
Diffstat (limited to 'drivers/watchdog/imx_sc_wdt.c')
| -rw-r--r-- | drivers/watchdog/imx_sc_wdt.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c new file mode 100644 index 000000000..8ac021748 --- /dev/null +++ b/drivers/watchdog/imx_sc_wdt.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2018-2019 NXP. + */ + +#include <linux/arm-smccc.h> +#include <linux/firmware/imx/sci.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +#define DEFAULT_TIMEOUT 60 +/* + * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms + * in theory, but for normal case, 1s~128s is enough, you can change this max + * value in case it's not enough. + */ +#define MAX_TIMEOUT 128 + +#define IMX_SIP_TIMER 0xC2000002 +#define IMX_SIP_TIMER_START_WDOG 0x01 +#define IMX_SIP_TIMER_STOP_WDOG 0x02 +#define IMX_SIP_TIMER_SET_WDOG_ACT 0x03 +#define IMX_SIP_TIMER_PING_WDOG 0x04 +#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05 +#define IMX_SIP_TIMER_GET_WDOG_STAT 0x06 +#define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07 + +#define SC_TIMER_WDOG_ACTION_PARTITION 0 + +#define SC_IRQ_WDOG 1 +#define SC_IRQ_GROUP_WDOG 1 + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0000); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +struct imx_sc_wdt_device { + struct watchdog_device wdd; + struct notifier_block wdt_notifier; +}; + +static int imx_sc_wdt_ping(struct watchdog_device *wdog) +{ + struct arm_smccc_res res; + + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG, + 0, 0, 0, 0, 0, 0, &res); + + return 0; +} + +static int imx_sc_wdt_start(struct watchdog_device *wdog) +{ + struct arm_smccc_res res; + + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG, + 0, 0, 0, 0, 0, 0, &res); + if (res.a0) + return -EACCES; + + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT, + SC_TIMER_WDOG_ACTION_PARTITION, + 0, 0, 0, 0, 0, &res); + return res.a0 ? -EACCES : 0; +} + +static int imx_sc_wdt_stop(struct watchdog_device *wdog) +{ + struct arm_smccc_res res; + + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG, + 0, 0, 0, 0, 0, 0, &res); + + return res.a0 ? -EACCES : 0; +} + +static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int timeout) +{ + struct arm_smccc_res res; + + wdog->timeout = timeout; + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG, + timeout * 1000, 0, 0, 0, 0, 0, &res); + + return res.a0 ? -EACCES : 0; +} + +static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog, + unsigned int pretimeout) +{ + struct arm_smccc_res res; + + /* + * SCU firmware calculates pretimeout based on current time + * stamp instead of watchdog timeout stamp, need to convert + * the pretimeout to SCU firmware's timeout value. + */ + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG, + (wdog->timeout - pretimeout) * 1000, 0, 0, 0, + 0, 0, &res); + if (res.a0) + return -EACCES; + + wdog->pretimeout = pretimeout; + + return 0; +} + +static int imx_sc_wdt_notify(struct notifier_block *nb, + unsigned long event, void *group) +{ + struct imx_sc_wdt_device *imx_sc_wdd = + container_of(nb, + struct imx_sc_wdt_device, + wdt_notifier); + + if (event & SC_IRQ_WDOG && + *(u8 *)group == SC_IRQ_GROUP_WDOG) + watchdog_notify_pretimeout(&imx_sc_wdd->wdd); + + return 0; +} + +static void imx_sc_wdt_action(void *data) +{ + struct notifier_block *wdt_notifier = data; + + imx_scu_irq_unregister_notifier(wdt_notifier); + imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, + SC_IRQ_WDOG, + false); +} + +static const struct watchdog_ops imx_sc_wdt_ops = { + .owner = THIS_MODULE, + .start = imx_sc_wdt_start, + .stop = imx_sc_wdt_stop, + .ping = imx_sc_wdt_ping, + .set_timeout = imx_sc_wdt_set_timeout, + .set_pretimeout = imx_sc_wdt_set_pretimeout, +}; + +static struct watchdog_info imx_sc_wdt_info = { + .identity = "i.MX SC watchdog timer", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +static int imx_sc_wdt_probe(struct platform_device *pdev) +{ + struct imx_sc_wdt_device *imx_sc_wdd; + struct watchdog_device *wdog; + struct device *dev = &pdev->dev; + int ret; + + imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL); + if (!imx_sc_wdd) + return -ENOMEM; + + platform_set_drvdata(pdev, imx_sc_wdd); + + wdog = &imx_sc_wdd->wdd; + wdog->info = &imx_sc_wdt_info; + wdog->ops = &imx_sc_wdt_ops; + wdog->min_timeout = 1; + wdog->max_timeout = MAX_TIMEOUT; + wdog->parent = dev; + wdog->timeout = DEFAULT_TIMEOUT; + + watchdog_init_timeout(wdog, 0, dev); + + ret = imx_sc_wdt_set_timeout(wdog, wdog->timeout); + if (ret) + return ret; + + watchdog_stop_on_reboot(wdog); + watchdog_stop_on_unregister(wdog); + + ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, + SC_IRQ_WDOG, + true); + if (ret) { + dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n"); + goto register_device; + } + + imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify; + ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier); + if (ret) { + imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, + SC_IRQ_WDOG, + false); + dev_warn(dev, + "Register irq notifier failed, pretimeout NOT supported\n"); + goto register_device; + } + + ret = devm_add_action_or_reset(dev, imx_sc_wdt_action, + &imx_sc_wdd->wdt_notifier); + if (!ret) + imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT; + else + dev_warn(dev, "Add action failed, pretimeout NOT supported\n"); + +register_device: + return devm_watchdog_register_device(dev, wdog); +} + +static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) +{ + struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); + + if (watchdog_active(&imx_sc_wdd->wdd)) + imx_sc_wdt_stop(&imx_sc_wdd->wdd); + + return 0; +} + +static int __maybe_unused imx_sc_wdt_resume(struct device *dev) +{ + struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); + + if (watchdog_active(&imx_sc_wdd->wdd)) + imx_sc_wdt_start(&imx_sc_wdd->wdd); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops, + imx_sc_wdt_suspend, imx_sc_wdt_resume); + +static const struct of_device_id imx_sc_wdt_dt_ids[] = { + { .compatible = "fsl,imx-sc-wdt", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids); + +static struct platform_driver imx_sc_wdt_driver = { + .probe = imx_sc_wdt_probe, + .driver = { + .name = "imx-sc-wdt", + .of_match_table = imx_sc_wdt_dt_ids, + .pm = &imx_sc_wdt_pm_ops, + }, +}; +module_platform_driver(imx_sc_wdt_driver); + +MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>"); +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver"); +MODULE_LICENSE("GPL v2"); |