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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
473cf939 JC |
2 | /* |
3 | * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer | |
4 | * | |
5 | * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> | |
f3519a66 | 6 | * Copyright (C) 2013 John Crispin <john@phrozen.org> |
473cf939 JC |
7 | * |
8 | * This driver was based on: drivers/watchdog/softdog.c | |
473cf939 JC |
9 | */ |
10 | ||
11 | #include <linux/clk.h> | |
12 | #include <linux/reset.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/watchdog.h> | |
473cf939 JC |
16 | #include <linux/moduleparam.h> |
17 | #include <linux/platform_device.h> | |
3aa8b8bb | 18 | #include <linux/mod_devicetable.h> |
473cf939 JC |
19 | |
20 | #include <asm/mach-ralink/ralink_regs.h> | |
21 | ||
22 | #define SYSC_RSTSTAT 0x38 | |
23 | #define WDT_RST_CAUSE BIT(1) | |
24 | ||
25 | #define RALINK_WDT_TIMEOUT 30 | |
26 | #define RALINK_WDT_PRESCALE 65536 | |
27 | ||
28 | #define TIMER_REG_TMR1LOAD 0x00 | |
29 | #define TIMER_REG_TMR1CTL 0x08 | |
30 | ||
31 | #define TMRSTAT_TMR1RST BIT(5) | |
32 | ||
33 | #define TMR1CTL_ENABLE BIT(7) | |
34 | #define TMR1CTL_MODE_SHIFT 4 | |
35 | #define TMR1CTL_MODE_MASK 0x3 | |
36 | #define TMR1CTL_MODE_FREE_RUNNING 0x0 | |
37 | #define TMR1CTL_MODE_PERIODIC 0x1 | |
38 | #define TMR1CTL_MODE_TIMEOUT 0x2 | |
39 | #define TMR1CTL_MODE_WDT 0x3 | |
40 | #define TMR1CTL_PRESCALE_MASK 0xf | |
41 | #define TMR1CTL_PRESCALE_65536 0xf | |
42 | ||
76ad36bf SP |
43 | struct rt2880_wdt_data { |
44 | void __iomem *base; | |
45 | unsigned long freq; | |
46 | struct clk *clk; | |
47 | struct reset_control *rst; | |
48 | struct watchdog_device wdt; | |
49 | }; | |
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 | ||
af3ac8e4 | 57 | static inline void rt_wdt_w32(void __iomem *base, unsigned int reg, u32 val) |
473cf939 | 58 | { |
76ad36bf | 59 | iowrite32(val, base + reg); |
473cf939 JC |
60 | } |
61 | ||
af3ac8e4 | 62 | static inline u32 rt_wdt_r32(void __iomem *base, unsigned int reg) |
473cf939 | 63 | { |
76ad36bf | 64 | return ioread32(base + reg); |
473cf939 JC |
65 | } |
66 | ||
67 | static int rt288x_wdt_ping(struct watchdog_device *w) | |
68 | { | |
76ad36bf SP |
69 | struct rt2880_wdt_data *drvdata = watchdog_get_drvdata(w); |
70 | ||
71 | rt_wdt_w32(drvdata->base, TIMER_REG_TMR1LOAD, w->timeout * drvdata->freq); | |
473cf939 JC |
72 | |
73 | return 0; | |
74 | } | |
75 | ||
76 | static int rt288x_wdt_start(struct watchdog_device *w) | |
77 | { | |
76ad36bf | 78 | struct rt2880_wdt_data *drvdata = watchdog_get_drvdata(w); |
473cf939 JC |
79 | u32 t; |
80 | ||
76ad36bf | 81 | t = rt_wdt_r32(drvdata->base, TIMER_REG_TMR1CTL); |
473cf939 JC |
82 | t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT | |
83 | TMR1CTL_PRESCALE_MASK); | |
84 | t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT | | |
85 | TMR1CTL_PRESCALE_65536); | |
76ad36bf | 86 | rt_wdt_w32(drvdata->base, TIMER_REG_TMR1CTL, t); |
473cf939 JC |
87 | |
88 | rt288x_wdt_ping(w); | |
89 | ||
76ad36bf | 90 | t = rt_wdt_r32(drvdata->base, TIMER_REG_TMR1CTL); |
473cf939 | 91 | t |= TMR1CTL_ENABLE; |
76ad36bf | 92 | rt_wdt_w32(drvdata->base, TIMER_REG_TMR1CTL, t); |
473cf939 JC |
93 | |
94 | return 0; | |
95 | } | |
96 | ||
97 | static int rt288x_wdt_stop(struct watchdog_device *w) | |
98 | { | |
76ad36bf | 99 | struct rt2880_wdt_data *drvdata = watchdog_get_drvdata(w); |
473cf939 JC |
100 | u32 t; |
101 | ||
102 | rt288x_wdt_ping(w); | |
103 | ||
76ad36bf | 104 | t = rt_wdt_r32(drvdata->base, TIMER_REG_TMR1CTL); |
473cf939 | 105 | t &= ~TMR1CTL_ENABLE; |
76ad36bf | 106 | rt_wdt_w32(drvdata->base, TIMER_REG_TMR1CTL, t); |
473cf939 JC |
107 | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t) | |
112 | { | |
113 | w->timeout = t; | |
114 | rt288x_wdt_ping(w); | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | static int rt288x_wdt_bootcause(void) | |
120 | { | |
121 | if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) | |
122 | return WDIOF_CARDRESET; | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
323edb2e | 127 | static const struct watchdog_info rt288x_wdt_info = { |
473cf939 JC |
128 | .identity = "Ralink Watchdog", |
129 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
130 | }; | |
131 | ||
b893e344 | 132 | static const struct watchdog_ops rt288x_wdt_ops = { |
473cf939 JC |
133 | .owner = THIS_MODULE, |
134 | .start = rt288x_wdt_start, | |
135 | .stop = rt288x_wdt_stop, | |
136 | .ping = rt288x_wdt_ping, | |
137 | .set_timeout = rt288x_wdt_set_timeout, | |
138 | }; | |
139 | ||
473cf939 JC |
140 | static int rt288x_wdt_probe(struct platform_device *pdev) |
141 | { | |
570927df | 142 | struct device *dev = &pdev->dev; |
76ad36bf SP |
143 | struct watchdog_device *wdt; |
144 | struct rt2880_wdt_data *drvdata; | |
473cf939 JC |
145 | int ret; |
146 | ||
76ad36bf SP |
147 | drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); |
148 | if (!drvdata) | |
149 | return -ENOMEM; | |
150 | ||
151 | drvdata->base = devm_platform_ioremap_resource(pdev, 0); | |
152 | if (IS_ERR(drvdata->base)) | |
153 | return PTR_ERR(drvdata->base); | |
473cf939 | 154 | |
76ad36bf SP |
155 | drvdata->clk = devm_clk_get(dev, NULL); |
156 | if (IS_ERR(drvdata->clk)) | |
157 | return PTR_ERR(drvdata->clk); | |
473cf939 | 158 | |
76ad36bf SP |
159 | drvdata->rst = devm_reset_control_get_exclusive(dev, NULL); |
160 | if (!IS_ERR(drvdata->rst)) | |
161 | reset_control_deassert(drvdata->rst); | |
473cf939 | 162 | |
76ad36bf | 163 | drvdata->freq = clk_get_rate(drvdata->clk) / RALINK_WDT_PRESCALE; |
473cf939 | 164 | |
76ad36bf SP |
165 | wdt = &drvdata->wdt; |
166 | wdt->info = &rt288x_wdt_info; | |
167 | wdt->ops = &rt288x_wdt_ops; | |
168 | wdt->min_timeout = 1; | |
169 | wdt->max_timeout = (0xfffful / drvdata->freq); | |
170 | wdt->parent = dev; | |
171 | wdt->bootstatus = rt288x_wdt_bootcause(); | |
473cf939 | 172 | |
76ad36bf SP |
173 | watchdog_init_timeout(wdt, wdt->max_timeout, dev); |
174 | watchdog_set_nowayout(wdt, nowayout); | |
175 | watchdog_set_drvdata(wdt, drvdata); | |
473cf939 | 176 | |
76ad36bf SP |
177 | watchdog_stop_on_reboot(wdt); |
178 | ret = devm_watchdog_register_device(dev, &drvdata->wdt); | |
473cf939 | 179 | if (!ret) |
570927df | 180 | dev_info(dev, "Initialized\n"); |
473cf939 JC |
181 | |
182 | return 0; | |
183 | } | |
184 | ||
473cf939 JC |
185 | static const struct of_device_id rt288x_wdt_match[] = { |
186 | { .compatible = "ralink,rt2880-wdt" }, | |
187 | {}, | |
188 | }; | |
189 | MODULE_DEVICE_TABLE(of, rt288x_wdt_match); | |
190 | ||
191 | static struct platform_driver rt288x_wdt_driver = { | |
192 | .probe = rt288x_wdt_probe, | |
473cf939 JC |
193 | .driver = { |
194 | .name = KBUILD_MODNAME, | |
473cf939 JC |
195 | .of_match_table = rt288x_wdt_match, |
196 | }, | |
197 | }; | |
198 | ||
199 | module_platform_driver(rt288x_wdt_driver); | |
200 | ||
201 | MODULE_DESCRIPTION("MediaTek/Ralink RT288x/RT3xxx hardware watchdog driver"); | |
202 | MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org"); | |
203 | MODULE_LICENSE("GPL v2"); |