1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright 2018-2019 NXP. |
4 | */ |
5 | |
6 | #include <linux/arm-smccc.h> |
7 | #include <linux/firmware/imx/sci.h> |
8 | #include <linux/io.h> |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> |
12 | #include <linux/of.h> |
13 | #include <linux/platform_device.h> |
14 | #include <linux/watchdog.h> |
15 | |
16 | #define DEFAULT_TIMEOUT 60 |
17 | /* |
18 | * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms |
19 | * in theory, but for normal case, 1s~128s is enough, you can change this max |
20 | * value in case it's not enough. |
21 | */ |
22 | #define MAX_TIMEOUT 128 |
23 | |
24 | #define IMX_SIP_TIMER 0xC2000002 |
25 | #define IMX_SIP_TIMER_START_WDOG 0x01 |
26 | #define IMX_SIP_TIMER_STOP_WDOG 0x02 |
27 | #define IMX_SIP_TIMER_SET_WDOG_ACT 0x03 |
28 | #define IMX_SIP_TIMER_PING_WDOG 0x04 |
29 | #define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05 |
30 | #define IMX_SIP_TIMER_GET_WDOG_STAT 0x06 |
31 | #define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07 |
32 | |
33 | #define SC_TIMER_WDOG_ACTION_PARTITION 0 |
34 | |
35 | #define SC_IRQ_WDOG 1 |
36 | #define SC_IRQ_GROUP_WDOG 1 |
37 | |
38 | static bool nowayout = WATCHDOG_NOWAYOUT; |
39 | module_param(nowayout, bool, 0000); |
40 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
41 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")" ); |
42 | |
43 | struct imx_sc_wdt_device { |
44 | struct watchdog_device wdd; |
45 | struct notifier_block wdt_notifier; |
46 | }; |
47 | |
48 | static int imx_sc_wdt_ping(struct watchdog_device *wdog) |
49 | { |
50 | struct arm_smccc_res res; |
51 | |
52 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG, |
53 | 0, 0, 0, 0, 0, 0, &res); |
54 | |
55 | return 0; |
56 | } |
57 | |
58 | static int imx_sc_wdt_start(struct watchdog_device *wdog) |
59 | { |
60 | struct arm_smccc_res res; |
61 | |
62 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG, |
63 | 0, 0, 0, 0, 0, 0, &res); |
64 | if (res.a0) |
65 | return -EACCES; |
66 | |
67 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT, |
68 | SC_TIMER_WDOG_ACTION_PARTITION, |
69 | 0, 0, 0, 0, 0, &res); |
70 | return res.a0 ? -EACCES : 0; |
71 | } |
72 | |
73 | static int imx_sc_wdt_stop(struct watchdog_device *wdog) |
74 | { |
75 | struct arm_smccc_res res; |
76 | |
77 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG, |
78 | 0, 0, 0, 0, 0, 0, &res); |
79 | |
80 | return res.a0 ? -EACCES : 0; |
81 | } |
82 | |
83 | static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog, |
84 | unsigned int timeout) |
85 | { |
86 | struct arm_smccc_res res; |
87 | |
88 | wdog->timeout = timeout; |
89 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG, |
90 | timeout * 1000, 0, 0, 0, 0, 0, &res); |
91 | |
92 | return res.a0 ? -EACCES : 0; |
93 | } |
94 | |
95 | static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog, |
96 | unsigned int pretimeout) |
97 | { |
98 | struct arm_smccc_res res; |
99 | |
100 | /* |
101 | * SCU firmware calculates pretimeout based on current time |
102 | * stamp instead of watchdog timeout stamp, need to convert |
103 | * the pretimeout to SCU firmware's timeout value. |
104 | */ |
105 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG, |
106 | (wdog->timeout - pretimeout) * 1000, 0, 0, 0, |
107 | 0, 0, &res); |
108 | if (res.a0) |
109 | return -EACCES; |
110 | |
111 | wdog->pretimeout = pretimeout; |
112 | |
113 | return 0; |
114 | } |
115 | |
116 | static int imx_sc_wdt_notify(struct notifier_block *nb, |
117 | unsigned long event, void *group) |
118 | { |
119 | struct imx_sc_wdt_device *imx_sc_wdd = |
120 | container_of(nb, |
121 | struct imx_sc_wdt_device, |
122 | wdt_notifier); |
123 | |
124 | if (event & SC_IRQ_WDOG && |
125 | *(u8 *)group == SC_IRQ_GROUP_WDOG) |
126 | watchdog_notify_pretimeout(wdd: &imx_sc_wdd->wdd); |
127 | |
128 | return 0; |
129 | } |
130 | |
131 | static void imx_sc_wdt_action(void *data) |
132 | { |
133 | struct notifier_block *wdt_notifier = data; |
134 | |
135 | imx_scu_irq_unregister_notifier(nb: wdt_notifier); |
136 | imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, |
137 | SC_IRQ_WDOG, |
138 | enable: false); |
139 | } |
140 | |
141 | static const struct watchdog_ops imx_sc_wdt_ops = { |
142 | .owner = THIS_MODULE, |
143 | .start = imx_sc_wdt_start, |
144 | .stop = imx_sc_wdt_stop, |
145 | .ping = imx_sc_wdt_ping, |
146 | .set_timeout = imx_sc_wdt_set_timeout, |
147 | .set_pretimeout = imx_sc_wdt_set_pretimeout, |
148 | }; |
149 | |
150 | static struct watchdog_info imx_sc_wdt_info = { |
151 | .identity = "i.MX SC watchdog timer" , |
152 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
153 | WDIOF_MAGICCLOSE, |
154 | }; |
155 | |
156 | static int imx_sc_wdt_probe(struct platform_device *pdev) |
157 | { |
158 | struct imx_sc_wdt_device *imx_sc_wdd; |
159 | struct watchdog_device *wdog; |
160 | struct device *dev = &pdev->dev; |
161 | int ret; |
162 | |
163 | imx_sc_wdd = devm_kzalloc(dev, size: sizeof(*imx_sc_wdd), GFP_KERNEL); |
164 | if (!imx_sc_wdd) |
165 | return -ENOMEM; |
166 | |
167 | platform_set_drvdata(pdev, data: imx_sc_wdd); |
168 | |
169 | wdog = &imx_sc_wdd->wdd; |
170 | wdog->info = &imx_sc_wdt_info; |
171 | wdog->ops = &imx_sc_wdt_ops; |
172 | wdog->min_timeout = 1; |
173 | wdog->max_timeout = MAX_TIMEOUT; |
174 | wdog->parent = dev; |
175 | wdog->timeout = DEFAULT_TIMEOUT; |
176 | |
177 | watchdog_init_timeout(wdd: wdog, timeout_parm: 0, dev); |
178 | |
179 | ret = imx_sc_wdt_set_timeout(wdog, timeout: wdog->timeout); |
180 | if (ret) |
181 | return ret; |
182 | |
183 | watchdog_stop_on_reboot(wdd: wdog); |
184 | watchdog_stop_on_unregister(wdd: wdog); |
185 | |
186 | ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, |
187 | SC_IRQ_WDOG, |
188 | enable: true); |
189 | if (ret) { |
190 | dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n" ); |
191 | goto register_device; |
192 | } |
193 | |
194 | imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify; |
195 | ret = imx_scu_irq_register_notifier(nb: &imx_sc_wdd->wdt_notifier); |
196 | if (ret) { |
197 | imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, |
198 | SC_IRQ_WDOG, |
199 | enable: false); |
200 | dev_warn(dev, |
201 | "Register irq notifier failed, pretimeout NOT supported\n" ); |
202 | goto register_device; |
203 | } |
204 | |
205 | ret = devm_add_action_or_reset(dev, imx_sc_wdt_action, |
206 | &imx_sc_wdd->wdt_notifier); |
207 | if (!ret) |
208 | imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT; |
209 | else |
210 | dev_warn(dev, "Add action failed, pretimeout NOT supported\n" ); |
211 | |
212 | register_device: |
213 | return devm_watchdog_register_device(dev, wdog); |
214 | } |
215 | |
216 | static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) |
217 | { |
218 | struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); |
219 | |
220 | if (watchdog_active(wdd: &imx_sc_wdd->wdd)) |
221 | imx_sc_wdt_stop(wdog: &imx_sc_wdd->wdd); |
222 | |
223 | return 0; |
224 | } |
225 | |
226 | static int __maybe_unused imx_sc_wdt_resume(struct device *dev) |
227 | { |
228 | struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); |
229 | |
230 | if (watchdog_active(wdd: &imx_sc_wdd->wdd)) |
231 | imx_sc_wdt_start(wdog: &imx_sc_wdd->wdd); |
232 | |
233 | return 0; |
234 | } |
235 | |
236 | static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops, |
237 | imx_sc_wdt_suspend, imx_sc_wdt_resume); |
238 | |
239 | static const struct of_device_id imx_sc_wdt_dt_ids[] = { |
240 | { .compatible = "fsl,imx-sc-wdt" , }, |
241 | { /* sentinel */ } |
242 | }; |
243 | MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids); |
244 | |
245 | static struct platform_driver imx_sc_wdt_driver = { |
246 | .probe = imx_sc_wdt_probe, |
247 | .driver = { |
248 | .name = "imx-sc-wdt" , |
249 | .of_match_table = imx_sc_wdt_dt_ids, |
250 | .pm = &imx_sc_wdt_pm_ops, |
251 | }, |
252 | }; |
253 | module_platform_driver(imx_sc_wdt_driver); |
254 | |
255 | MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>" ); |
256 | MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver" ); |
257 | MODULE_LICENSE("GPL v2" ); |
258 | |