1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright 2018-2019 NXP.
6 #include <linux/arm-smccc.h>
7 #include <linux/firmware/imx/sci.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
14 #include <linux/platform_device.h>
15 #include <linux/reboot.h>
16 #include <linux/watchdog.h>
18 #define DEFAULT_TIMEOUT 60
20 * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms
21 * in theory, but for normal case, 1s~128s is enough, you can change this max
22 * value in case it's not enough.
24 #define MAX_TIMEOUT 128
26 #define IMX_SIP_TIMER 0xC2000002
27 #define IMX_SIP_TIMER_START_WDOG 0x01
28 #define IMX_SIP_TIMER_STOP_WDOG 0x02
29 #define IMX_SIP_TIMER_SET_WDOG_ACT 0x03
30 #define IMX_SIP_TIMER_PING_WDOG 0x04
31 #define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05
32 #define IMX_SIP_TIMER_GET_WDOG_STAT 0x06
33 #define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07
35 #define SC_TIMER_WDOG_ACTION_PARTITION 0
38 #define SC_IRQ_GROUP_WDOG 1
40 static bool nowayout = WATCHDOG_NOWAYOUT;
41 module_param(nowayout, bool, 0000);
42 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
43 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
45 struct imx_sc_wdt_device {
46 struct watchdog_device wdd;
47 struct notifier_block wdt_notifier;
50 static int imx_sc_wdt_ping(struct watchdog_device *wdog)
52 struct arm_smccc_res res;
54 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG,
55 0, 0, 0, 0, 0, 0, &res);
60 static int imx_sc_wdt_start(struct watchdog_device *wdog)
62 struct arm_smccc_res res;
64 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
65 0, 0, 0, 0, 0, 0, &res);
69 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT,
70 SC_TIMER_WDOG_ACTION_PARTITION,
72 return res.a0 ? -EACCES : 0;
75 static int imx_sc_wdt_stop(struct watchdog_device *wdog)
77 struct arm_smccc_res res;
79 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
80 0, 0, 0, 0, 0, 0, &res);
82 return res.a0 ? -EACCES : 0;
85 static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
88 struct arm_smccc_res res;
90 wdog->timeout = timeout;
91 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG,
92 timeout * 1000, 0, 0, 0, 0, 0, &res);
94 return res.a0 ? -EACCES : 0;
97 static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog,
98 unsigned int pretimeout)
100 struct arm_smccc_res res;
102 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG,
103 pretimeout * 1000, 0, 0, 0, 0, 0, &res);
107 wdog->pretimeout = pretimeout;
112 static int imx_sc_wdt_notify(struct notifier_block *nb,
113 unsigned long event, void *group)
115 struct imx_sc_wdt_device *imx_sc_wdd =
117 struct imx_sc_wdt_device,
120 if (event & SC_IRQ_WDOG &&
121 *(u8 *)group == SC_IRQ_GROUP_WDOG)
122 watchdog_notify_pretimeout(&imx_sc_wdd->wdd);
127 static void imx_sc_wdt_action(void *data)
129 struct notifier_block *wdt_notifier = data;
131 imx_scu_irq_unregister_notifier(wdt_notifier);
132 imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
137 static const struct watchdog_ops imx_sc_wdt_ops = {
138 .owner = THIS_MODULE,
139 .start = imx_sc_wdt_start,
140 .stop = imx_sc_wdt_stop,
141 .ping = imx_sc_wdt_ping,
142 .set_timeout = imx_sc_wdt_set_timeout,
143 .set_pretimeout = imx_sc_wdt_set_pretimeout,
146 static struct watchdog_info imx_sc_wdt_info = {
147 .identity = "i.MX SC watchdog timer",
148 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
152 static int imx_sc_wdt_probe(struct platform_device *pdev)
154 struct imx_sc_wdt_device *imx_sc_wdd;
155 struct watchdog_device *wdog;
156 struct device *dev = &pdev->dev;
159 imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
163 platform_set_drvdata(pdev, imx_sc_wdd);
165 wdog = &imx_sc_wdd->wdd;
166 wdog->info = &imx_sc_wdt_info;
167 wdog->ops = &imx_sc_wdt_ops;
168 wdog->min_timeout = 1;
169 wdog->max_timeout = MAX_TIMEOUT;
171 wdog->timeout = DEFAULT_TIMEOUT;
173 watchdog_init_timeout(wdog, 0, dev);
174 watchdog_stop_on_reboot(wdog);
175 watchdog_stop_on_unregister(wdog);
177 ret = devm_watchdog_register_device(dev, wdog);
181 ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
185 dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n");
189 imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify;
190 ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier);
192 imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
196 "Register irq notifier failed, pretimeout NOT supported\n");
200 ret = devm_add_action_or_reset(dev, imx_sc_wdt_action,
201 &imx_sc_wdd->wdt_notifier);
203 imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
205 dev_warn(dev, "Add action failed, pretimeout NOT supported\n");
210 static int __maybe_unused imx_sc_wdt_suspend(struct device *dev)
212 struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
214 if (watchdog_active(&imx_sc_wdd->wdd))
215 imx_sc_wdt_stop(&imx_sc_wdd->wdd);
220 static int __maybe_unused imx_sc_wdt_resume(struct device *dev)
222 struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
224 if (watchdog_active(&imx_sc_wdd->wdd))
225 imx_sc_wdt_start(&imx_sc_wdd->wdd);
230 static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops,
231 imx_sc_wdt_suspend, imx_sc_wdt_resume);
233 static const struct of_device_id imx_sc_wdt_dt_ids[] = {
234 { .compatible = "fsl,imx-sc-wdt", },
237 MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids);
239 static struct platform_driver imx_sc_wdt_driver = {
240 .probe = imx_sc_wdt_probe,
242 .name = "imx-sc-wdt",
243 .of_match_table = imx_sc_wdt_dt_ids,
244 .pm = &imx_sc_wdt_pm_ops,
247 module_platform_driver(imx_sc_wdt_driver);
249 MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
250 MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
251 MODULE_LICENSE("GPL v2");