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473cf939 JC |
1 | /* |
2 | * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer | |
3 | * | |
4 | * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> | |
f3519a66 | 5 | * Copyright (C) 2013 John Crispin <john@phrozen.org> |
473cf939 JC |
6 | * |
7 | * This driver was based on: drivers/watchdog/softdog.c | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms of the GNU General Public License version 2 as published | |
11 | * by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/clk.h> | |
15 | #include <linux/reset.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/watchdog.h> | |
473cf939 JC |
19 | #include <linux/moduleparam.h> |
20 | #include <linux/platform_device.h> | |
3aa8b8bb | 21 | #include <linux/mod_devicetable.h> |
473cf939 JC |
22 | |
23 | #include <asm/mach-ralink/ralink_regs.h> | |
24 | ||
25 | #define SYSC_RSTSTAT 0x38 | |
26 | #define WDT_RST_CAUSE BIT(1) | |
27 | ||
28 | #define RALINK_WDT_TIMEOUT 30 | |
29 | #define RALINK_WDT_PRESCALE 65536 | |
30 | ||
31 | #define TIMER_REG_TMR1LOAD 0x00 | |
32 | #define TIMER_REG_TMR1CTL 0x08 | |
33 | ||
34 | #define TMRSTAT_TMR1RST BIT(5) | |
35 | ||
36 | #define TMR1CTL_ENABLE BIT(7) | |
37 | #define TMR1CTL_MODE_SHIFT 4 | |
38 | #define TMR1CTL_MODE_MASK 0x3 | |
39 | #define TMR1CTL_MODE_FREE_RUNNING 0x0 | |
40 | #define TMR1CTL_MODE_PERIODIC 0x1 | |
41 | #define TMR1CTL_MODE_TIMEOUT 0x2 | |
42 | #define TMR1CTL_MODE_WDT 0x3 | |
43 | #define TMR1CTL_PRESCALE_MASK 0xf | |
44 | #define TMR1CTL_PRESCALE_65536 0xf | |
45 | ||
46 | static struct clk *rt288x_wdt_clk; | |
47 | static unsigned long rt288x_wdt_freq; | |
48 | static void __iomem *rt288x_wdt_base; | |
a6f8f81e | 49 | static struct reset_control *rt288x_wdt_reset; |
473cf939 JC |
50 | |
51 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
52 | module_param(nowayout, bool, 0); | |
53 | MODULE_PARM_DESC(nowayout, | |
54 | "Watchdog cannot be stopped once started (default=" | |
55 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
56 | ||
57 | static inline void rt_wdt_w32(unsigned reg, u32 val) | |
58 | { | |
59 | iowrite32(val, rt288x_wdt_base + reg); | |
60 | } | |
61 | ||
62 | static inline u32 rt_wdt_r32(unsigned reg) | |
63 | { | |
64 | return ioread32(rt288x_wdt_base + reg); | |
65 | } | |
66 | ||
67 | static int rt288x_wdt_ping(struct watchdog_device *w) | |
68 | { | |
69 | rt_wdt_w32(TIMER_REG_TMR1LOAD, w->timeout * rt288x_wdt_freq); | |
70 | ||
71 | return 0; | |
72 | } | |
73 | ||
74 | static int rt288x_wdt_start(struct watchdog_device *w) | |
75 | { | |
76 | u32 t; | |
77 | ||
78 | t = rt_wdt_r32(TIMER_REG_TMR1CTL); | |
79 | t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT | | |
80 | TMR1CTL_PRESCALE_MASK); | |
81 | t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT | | |
82 | TMR1CTL_PRESCALE_65536); | |
83 | rt_wdt_w32(TIMER_REG_TMR1CTL, t); | |
84 | ||
85 | rt288x_wdt_ping(w); | |
86 | ||
87 | t = rt_wdt_r32(TIMER_REG_TMR1CTL); | |
88 | t |= TMR1CTL_ENABLE; | |
89 | rt_wdt_w32(TIMER_REG_TMR1CTL, t); | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | static int rt288x_wdt_stop(struct watchdog_device *w) | |
95 | { | |
96 | u32 t; | |
97 | ||
98 | rt288x_wdt_ping(w); | |
99 | ||
100 | t = rt_wdt_r32(TIMER_REG_TMR1CTL); | |
101 | t &= ~TMR1CTL_ENABLE; | |
102 | rt_wdt_w32(TIMER_REG_TMR1CTL, t); | |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
107 | static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t) | |
108 | { | |
109 | w->timeout = t; | |
110 | rt288x_wdt_ping(w); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int rt288x_wdt_bootcause(void) | |
116 | { | |
117 | if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) | |
118 | return WDIOF_CARDRESET; | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
323edb2e | 123 | static const struct watchdog_info rt288x_wdt_info = { |
473cf939 JC |
124 | .identity = "Ralink Watchdog", |
125 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
126 | }; | |
127 | ||
b893e344 | 128 | static const struct watchdog_ops rt288x_wdt_ops = { |
473cf939 JC |
129 | .owner = THIS_MODULE, |
130 | .start = rt288x_wdt_start, | |
131 | .stop = rt288x_wdt_stop, | |
132 | .ping = rt288x_wdt_ping, | |
133 | .set_timeout = rt288x_wdt_set_timeout, | |
134 | }; | |
135 | ||
136 | static struct watchdog_device rt288x_wdt_dev = { | |
137 | .info = &rt288x_wdt_info, | |
138 | .ops = &rt288x_wdt_ops, | |
139 | .min_timeout = 1, | |
140 | }; | |
141 | ||
142 | static int rt288x_wdt_probe(struct platform_device *pdev) | |
143 | { | |
144 | struct resource *res; | |
145 | int ret; | |
146 | ||
147 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
0859ffc3 | 148 | rt288x_wdt_base = devm_ioremap_resource(&pdev->dev, res); |
473cf939 JC |
149 | if (IS_ERR(rt288x_wdt_base)) |
150 | return PTR_ERR(rt288x_wdt_base); | |
151 | ||
152 | rt288x_wdt_clk = devm_clk_get(&pdev->dev, NULL); | |
153 | if (IS_ERR(rt288x_wdt_clk)) | |
154 | return PTR_ERR(rt288x_wdt_clk); | |
155 | ||
a248e5e9 | 156 | rt288x_wdt_reset = devm_reset_control_get_exclusive(&pdev->dev, NULL); |
a6f8f81e JC |
157 | if (!IS_ERR(rt288x_wdt_reset)) |
158 | reset_control_deassert(rt288x_wdt_reset); | |
473cf939 JC |
159 | |
160 | rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE; | |
161 | ||
473cf939 | 162 | rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause(); |
473cf939 | 163 | rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq); |
6551881c | 164 | rt288x_wdt_dev.parent = &pdev->dev; |
473cf939 | 165 | |
a6f8f81e JC |
166 | watchdog_init_timeout(&rt288x_wdt_dev, rt288x_wdt_dev.max_timeout, |
167 | &pdev->dev); | |
473cf939 JC |
168 | watchdog_set_nowayout(&rt288x_wdt_dev, nowayout); |
169 | ||
170 | ret = watchdog_register_device(&rt288x_wdt_dev); | |
171 | if (!ret) | |
172 | dev_info(&pdev->dev, "Initialized\n"); | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | static int rt288x_wdt_remove(struct platform_device *pdev) | |
178 | { | |
179 | watchdog_unregister_device(&rt288x_wdt_dev); | |
180 | ||
181 | return 0; | |
182 | } | |
183 | ||
184 | static void rt288x_wdt_shutdown(struct platform_device *pdev) | |
185 | { | |
186 | rt288x_wdt_stop(&rt288x_wdt_dev); | |
187 | } | |
188 | ||
189 | static const struct of_device_id rt288x_wdt_match[] = { | |
190 | { .compatible = "ralink,rt2880-wdt" }, | |
191 | {}, | |
192 | }; | |
193 | MODULE_DEVICE_TABLE(of, rt288x_wdt_match); | |
194 | ||
195 | static struct platform_driver rt288x_wdt_driver = { | |
196 | .probe = rt288x_wdt_probe, | |
197 | .remove = rt288x_wdt_remove, | |
198 | .shutdown = rt288x_wdt_shutdown, | |
199 | .driver = { | |
200 | .name = KBUILD_MODNAME, | |
473cf939 JC |
201 | .of_match_table = rt288x_wdt_match, |
202 | }, | |
203 | }; | |
204 | ||
205 | module_platform_driver(rt288x_wdt_driver); | |
206 | ||
207 | MODULE_DESCRIPTION("MediaTek/Ralink RT288x/RT3xxx hardware watchdog driver"); | |
208 | MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org"); | |
209 | MODULE_LICENSE("GPL v2"); |