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