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13#include <linux/clk.h>
14#include <linux/reset.h>
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/watchdog.h>
18#include <linux/moduleparam.h>
19#include <linux/platform_device.h>
20
21#include <asm/mach-ralink/ralink_regs.h>
22
23#define SYSC_RSTSTAT 0x38
24#define WDT_RST_CAUSE BIT(1)
25
26#define RALINK_WDT_TIMEOUT 30
27
28#define TIMER_REG_TMRSTAT 0x00
29#define TIMER_REG_TMR1LOAD 0x24
30#define TIMER_REG_TMR1CTL 0x20
31
32#define TMR1CTL_ENABLE BIT(7)
33#define TMR1CTL_RESTART BIT(9)
34#define TMR1CTL_PRESCALE_SHIFT 16
35
36static void __iomem *mt7621_wdt_base;
37static struct reset_control *mt7621_wdt_reset;
38
39static bool nowayout = WATCHDOG_NOWAYOUT;
40module_param(nowayout, bool, 0);
41MODULE_PARM_DESC(nowayout,
42 "Watchdog cannot be stopped once started (default="
43 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
44
45static inline void rt_wdt_w32(unsigned reg, u32 val)
46{
47 iowrite32(val, mt7621_wdt_base + reg);
48}
49
50static inline u32 rt_wdt_r32(unsigned reg)
51{
52 return ioread32(mt7621_wdt_base + reg);
53}
54
55static int mt7621_wdt_ping(struct watchdog_device *w)
56{
57 rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART);
58
59 return 0;
60}
61
62static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
63{
64 w->timeout = t;
65 rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000);
66 mt7621_wdt_ping(w);
67
68 return 0;
69}
70
71static int mt7621_wdt_start(struct watchdog_device *w)
72{
73 u32 t;
74
75
76 rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT);
77
78 mt7621_wdt_set_timeout(w, w->timeout);
79
80 t = rt_wdt_r32(TIMER_REG_TMR1CTL);
81 t |= TMR1CTL_ENABLE;
82 rt_wdt_w32(TIMER_REG_TMR1CTL, t);
83
84 return 0;
85}
86
87static int mt7621_wdt_stop(struct watchdog_device *w)
88{
89 u32 t;
90
91 mt7621_wdt_ping(w);
92
93 t = rt_wdt_r32(TIMER_REG_TMR1CTL);
94 t &= ~TMR1CTL_ENABLE;
95 rt_wdt_w32(TIMER_REG_TMR1CTL, t);
96
97 return 0;
98}
99
100static int mt7621_wdt_bootcause(void)
101{
102 if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
103 return WDIOF_CARDRESET;
104
105 return 0;
106}
107
108static int mt7621_wdt_is_running(struct watchdog_device *w)
109{
110 return !!(rt_wdt_r32(TIMER_REG_TMR1CTL) & TMR1CTL_ENABLE);
111}
112
113static const struct watchdog_info mt7621_wdt_info = {
114 .identity = "Mediatek Watchdog",
115 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
116};
117
118static const struct watchdog_ops mt7621_wdt_ops = {
119 .owner = THIS_MODULE,
120 .start = mt7621_wdt_start,
121 .stop = mt7621_wdt_stop,
122 .ping = mt7621_wdt_ping,
123 .set_timeout = mt7621_wdt_set_timeout,
124};
125
126static struct watchdog_device mt7621_wdt_dev = {
127 .info = &mt7621_wdt_info,
128 .ops = &mt7621_wdt_ops,
129 .min_timeout = 1,
130 .max_timeout = 0xfffful / 1000,
131};
132
133static int mt7621_wdt_probe(struct platform_device *pdev)
134{
135 struct resource *res;
136
137 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
138 mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res);
139 if (IS_ERR(mt7621_wdt_base))
140 return PTR_ERR(mt7621_wdt_base);
141
142 mt7621_wdt_reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
143 if (!IS_ERR(mt7621_wdt_reset))
144 reset_control_deassert(mt7621_wdt_reset);
145
146 mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause();
147
148 watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout,
149 &pdev->dev);
150 watchdog_set_nowayout(&mt7621_wdt_dev, nowayout);
151 if (mt7621_wdt_is_running(&mt7621_wdt_dev)) {
152
153
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159
160
161 mt7621_wdt_stop(&mt7621_wdt_dev);
162 mt7621_wdt_start(&mt7621_wdt_dev);
163 set_bit(WDOG_HW_RUNNING, &mt7621_wdt_dev.status);
164 }
165
166 return devm_watchdog_register_device(&pdev->dev, &mt7621_wdt_dev);
167}
168
169static void mt7621_wdt_shutdown(struct platform_device *pdev)
170{
171 mt7621_wdt_stop(&mt7621_wdt_dev);
172}
173
174static const struct of_device_id mt7621_wdt_match[] = {
175 { .compatible = "mediatek,mt7621-wdt" },
176 {},
177};
178MODULE_DEVICE_TABLE(of, mt7621_wdt_match);
179
180static struct platform_driver mt7621_wdt_driver = {
181 .probe = mt7621_wdt_probe,
182 .shutdown = mt7621_wdt_shutdown,
183 .driver = {
184 .name = KBUILD_MODNAME,
185 .of_match_table = mt7621_wdt_match,
186 },
187};
188
189module_platform_driver(mt7621_wdt_driver);
190
191MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver");
192MODULE_AUTHOR("John Crispin <john@phrozen.org");
193MODULE_LICENSE("GPL v2");
194
