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 | #define SC_TIMER_ERR_BUSY 10 |
38 | |
39 | static bool nowayout = WATCHDOG_NOWAYOUT; |
40 | module_param(nowayout, bool, 0000); |
41 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
42 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")" ); |
43 | |
44 | struct imx_sc_wdt_device { |
45 | struct watchdog_device wdd; |
46 | struct notifier_block wdt_notifier; |
47 | }; |
48 | |
49 | static int imx_sc_wdt_ping(struct watchdog_device *wdog) |
50 | { |
51 | struct arm_smccc_res res; |
52 | |
53 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG, |
54 | 0, 0, 0, 0, 0, 0, &res); |
55 | |
56 | return 0; |
57 | } |
58 | |
59 | static int imx_sc_wdt_start(struct watchdog_device *wdog) |
60 | { |
61 | struct arm_smccc_res res; |
62 | |
63 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG, |
64 | 0, 0, 0, 0, 0, 0, &res); |
65 | |
66 | /* Ignore if already enabled(SC_TIMER_ERR_BUSY) */ |
67 | if (res.a0 && res.a0 != SC_TIMER_ERR_BUSY) |
68 | return -EACCES; |
69 | |
70 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT, |
71 | SC_TIMER_WDOG_ACTION_PARTITION, |
72 | 0, 0, 0, 0, 0, &res); |
73 | return res.a0 ? -EACCES : 0; |
74 | } |
75 | |
76 | static int imx_sc_wdt_stop(struct watchdog_device *wdog) |
77 | { |
78 | struct arm_smccc_res res; |
79 | |
80 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG, |
81 | 0, 0, 0, 0, 0, 0, &res); |
82 | |
83 | return res.a0 ? -EACCES : 0; |
84 | } |
85 | |
86 | static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog, |
87 | unsigned int timeout) |
88 | { |
89 | struct arm_smccc_res res; |
90 | |
91 | wdog->timeout = timeout; |
92 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG, |
93 | timeout * 1000, 0, 0, 0, 0, 0, &res); |
94 | |
95 | return res.a0 ? -EACCES : 0; |
96 | } |
97 | |
98 | static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog, |
99 | unsigned int pretimeout) |
100 | { |
101 | struct arm_smccc_res res; |
102 | |
103 | /* |
104 | * SCU firmware calculates pretimeout based on current time |
105 | * stamp instead of watchdog timeout stamp, need to convert |
106 | * the pretimeout to SCU firmware's timeout value. |
107 | */ |
108 | arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG, |
109 | (wdog->timeout - pretimeout) * 1000, 0, 0, 0, |
110 | 0, 0, &res); |
111 | if (res.a0) |
112 | return -EACCES; |
113 | |
114 | wdog->pretimeout = pretimeout; |
115 | |
116 | return 0; |
117 | } |
118 | |
119 | static int imx_sc_wdt_notify(struct notifier_block *nb, |
120 | unsigned long event, void *group) |
121 | { |
122 | struct imx_sc_wdt_device *imx_sc_wdd = |
123 | container_of(nb, |
124 | struct imx_sc_wdt_device, |
125 | wdt_notifier); |
126 | |
127 | if (event & SC_IRQ_WDOG && |
128 | *(u8 *)group == SC_IRQ_GROUP_WDOG) |
129 | watchdog_notify_pretimeout(wdd: &imx_sc_wdd->wdd); |
130 | |
131 | return 0; |
132 | } |
133 | |
134 | static void imx_sc_wdt_action(void *data) |
135 | { |
136 | struct notifier_block *wdt_notifier = data; |
137 | |
138 | imx_scu_irq_unregister_notifier(nb: wdt_notifier); |
139 | imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, |
140 | SC_IRQ_WDOG, |
141 | enable: false); |
142 | } |
143 | |
144 | static const struct watchdog_ops imx_sc_wdt_ops = { |
145 | .owner = THIS_MODULE, |
146 | .start = imx_sc_wdt_start, |
147 | .stop = imx_sc_wdt_stop, |
148 | .ping = imx_sc_wdt_ping, |
149 | .set_timeout = imx_sc_wdt_set_timeout, |
150 | .set_pretimeout = imx_sc_wdt_set_pretimeout, |
151 | }; |
152 | |
153 | static struct watchdog_info imx_sc_wdt_info = { |
154 | .identity = "i.MX SC watchdog timer" , |
155 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
156 | WDIOF_MAGICCLOSE, |
157 | }; |
158 | |
159 | static int imx_sc_wdt_probe(struct platform_device *pdev) |
160 | { |
161 | struct imx_sc_wdt_device *imx_sc_wdd; |
162 | struct watchdog_device *wdog; |
163 | struct device *dev = &pdev->dev; |
164 | int ret; |
165 | |
166 | imx_sc_wdd = devm_kzalloc(dev, size: sizeof(*imx_sc_wdd), GFP_KERNEL); |
167 | if (!imx_sc_wdd) |
168 | return -ENOMEM; |
169 | |
170 | platform_set_drvdata(pdev, data: imx_sc_wdd); |
171 | |
172 | wdog = &imx_sc_wdd->wdd; |
173 | wdog->info = &imx_sc_wdt_info; |
174 | wdog->ops = &imx_sc_wdt_ops; |
175 | wdog->min_timeout = 1; |
176 | wdog->max_timeout = MAX_TIMEOUT; |
177 | wdog->parent = dev; |
178 | wdog->timeout = DEFAULT_TIMEOUT; |
179 | |
180 | watchdog_init_timeout(wdd: wdog, timeout_parm: 0, dev); |
181 | |
182 | ret = imx_sc_wdt_set_timeout(wdog, timeout: wdog->timeout); |
183 | if (ret) |
184 | return ret; |
185 | |
186 | watchdog_stop_on_reboot(wdd: wdog); |
187 | watchdog_stop_on_unregister(wdd: wdog); |
188 | |
189 | ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, |
190 | SC_IRQ_WDOG, |
191 | enable: true); |
192 | if (ret) { |
193 | dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n" ); |
194 | goto register_device; |
195 | } |
196 | |
197 | imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify; |
198 | ret = imx_scu_irq_register_notifier(nb: &imx_sc_wdd->wdt_notifier); |
199 | if (ret) { |
200 | imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, |
201 | SC_IRQ_WDOG, |
202 | enable: false); |
203 | dev_warn(dev, |
204 | "Register irq notifier failed, pretimeout NOT supported\n" ); |
205 | goto register_device; |
206 | } |
207 | |
208 | ret = devm_add_action_or_reset(dev, imx_sc_wdt_action, |
209 | &imx_sc_wdd->wdt_notifier); |
210 | if (!ret) |
211 | imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT; |
212 | else |
213 | dev_warn(dev, "Add action failed, pretimeout NOT supported\n" ); |
214 | |
215 | register_device: |
216 | return devm_watchdog_register_device(dev, wdog); |
217 | } |
218 | |
219 | static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) |
220 | { |
221 | struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); |
222 | |
223 | if (watchdog_active(wdd: &imx_sc_wdd->wdd)) |
224 | imx_sc_wdt_stop(wdog: &imx_sc_wdd->wdd); |
225 | |
226 | return 0; |
227 | } |
228 | |
229 | static int __maybe_unused imx_sc_wdt_resume(struct device *dev) |
230 | { |
231 | struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); |
232 | |
233 | if (watchdog_active(wdd: &imx_sc_wdd->wdd)) |
234 | imx_sc_wdt_start(wdog: &imx_sc_wdd->wdd); |
235 | |
236 | return 0; |
237 | } |
238 | |
239 | static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops, |
240 | imx_sc_wdt_suspend, imx_sc_wdt_resume); |
241 | |
242 | static const struct of_device_id imx_sc_wdt_dt_ids[] = { |
243 | { .compatible = "fsl,imx-sc-wdt" , }, |
244 | { /* sentinel */ } |
245 | }; |
246 | MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids); |
247 | |
248 | static struct platform_driver imx_sc_wdt_driver = { |
249 | .probe = imx_sc_wdt_probe, |
250 | .driver = { |
251 | .name = "imx-sc-wdt" , |
252 | .of_match_table = imx_sc_wdt_dt_ids, |
253 | .pm = &imx_sc_wdt_pm_ops, |
254 | }, |
255 | }; |
256 | module_platform_driver(imx_sc_wdt_driver); |
257 | |
258 | MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>" ); |
259 | MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver" ); |
260 | MODULE_LICENSE("GPL v2" ); |
261 | |