// 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
#define SC_TIMER_ERR_BUSY 10
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);
/* Ignore if already enabled(SC_TIMER_ERR_BUSY) */
if (res.a0 && res.a0 != SC_TIMER_ERR_BUSY)
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 <[email protected]>");
MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
MODULE_LICENSE("GPL v2");
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