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11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/module.h>
14#include <linux/smp.h>
15#include <linux/watchdog.h>
16
17#include <asm/reg_booke.h>
18#include <asm/time.h>
19#include <asm/div64.h>
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29
30#ifdef CONFIG_PPC_FSL_BOOK3E
31#define WDTP(x) ((((x)&0x3)<<30)|(((x)&0x3c)<<15))
32#define WDTP_MASK (WDTP(0x3f))
33#else
34#define WDTP(x) (TCR_WP(x))
35#define WDTP_MASK (TCR_WP_MASK)
36#endif
37
38static bool booke_wdt_enabled;
39module_param(booke_wdt_enabled, bool, 0);
40static int booke_wdt_period = CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT;
41module_param(booke_wdt_period, int, 0);
42
43#ifdef CONFIG_PPC_FSL_BOOK3E
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54
55static unsigned long long period_to_sec(unsigned int period)
56{
57 unsigned long long tmp = 1ULL << (64 - period);
58 unsigned long tmp2 = ppc_tb_freq;
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60
61
62
63 tmp2 = tmp2 / 5 * 2;
64
65 do_div(tmp, tmp2);
66 return tmp;
67}
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73
74static unsigned int sec_to_period(unsigned int secs)
75{
76 unsigned int period;
77 for (period = 63; period > 0; period--) {
78 if (period_to_sec(period) >= secs)
79 return period;
80 }
81 return 0;
82}
83
84#define MAX_WDT_TIMEOUT period_to_sec(1)
85
86#else
87
88static unsigned long long period_to_sec(unsigned int period)
89{
90 return period;
91}
92
93static unsigned int sec_to_period(unsigned int secs)
94{
95 return secs;
96}
97
98#define MAX_WDT_TIMEOUT 3
99
100#endif
101
102static void __booke_wdt_set(void *data)
103{
104 u32 val;
105 struct watchdog_device *wdog = data;
106
107 val = mfspr(SPRN_TCR);
108 val &= ~WDTP_MASK;
109 val |= WDTP(sec_to_period(wdog->timeout));
110
111 mtspr(SPRN_TCR, val);
112}
113
114static void booke_wdt_set(void *data)
115{
116 on_each_cpu(__booke_wdt_set, data, 0);
117}
118
119static void __booke_wdt_ping(void *data)
120{
121 mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
122}
123
124static int booke_wdt_ping(struct watchdog_device *wdog)
125{
126 on_each_cpu(__booke_wdt_ping, NULL, 0);
127
128 return 0;
129}
130
131static void __booke_wdt_enable(void *data)
132{
133 u32 val;
134 struct watchdog_device *wdog = data;
135
136
137 __booke_wdt_ping(NULL);
138 val = mfspr(SPRN_TCR);
139 val &= ~WDTP_MASK;
140 val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(sec_to_period(wdog->timeout)));
141
142 mtspr(SPRN_TCR, val);
143}
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152
153static void __booke_wdt_disable(void *data)
154{
155 u32 val;
156
157 val = mfspr(SPRN_TCR);
158 val &= ~(TCR_WIE | WDTP_MASK);
159 mtspr(SPRN_TCR, val);
160
161
162 __booke_wdt_ping(NULL);
163
164}
165
166static int booke_wdt_start(struct watchdog_device *wdog)
167{
168 on_each_cpu(__booke_wdt_enable, wdog, 0);
169 pr_debug("watchdog enabled (timeout = %u sec)\n", wdog->timeout);
170
171 return 0;
172}
173
174static int booke_wdt_stop(struct watchdog_device *wdog)
175{
176 on_each_cpu(__booke_wdt_disable, NULL, 0);
177 pr_debug("watchdog disabled\n");
178
179 return 0;
180}
181
182static int booke_wdt_set_timeout(struct watchdog_device *wdt_dev,
183 unsigned int timeout)
184{
185 wdt_dev->timeout = timeout;
186 booke_wdt_set(wdt_dev);
187
188 return 0;
189}
190
191static struct watchdog_info booke_wdt_info __ro_after_init = {
192 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
193 .identity = "PowerPC Book-E Watchdog",
194};
195
196static const struct watchdog_ops booke_wdt_ops = {
197 .owner = THIS_MODULE,
198 .start = booke_wdt_start,
199 .stop = booke_wdt_stop,
200 .ping = booke_wdt_ping,
201 .set_timeout = booke_wdt_set_timeout,
202};
203
204static struct watchdog_device booke_wdt_dev = {
205 .info = &booke_wdt_info,
206 .ops = &booke_wdt_ops,
207 .min_timeout = 1,
208};
209
210static void __exit booke_wdt_exit(void)
211{
212 watchdog_unregister_device(&booke_wdt_dev);
213}
214
215static int __init booke_wdt_init(void)
216{
217 int ret = 0;
218 bool nowayout = WATCHDOG_NOWAYOUT;
219
220 pr_info("powerpc book-e watchdog driver loaded\n");
221 booke_wdt_info.firmware_version = cur_cpu_spec->pvr_value;
222 booke_wdt_set_timeout(&booke_wdt_dev,
223 period_to_sec(booke_wdt_period));
224 watchdog_set_nowayout(&booke_wdt_dev, nowayout);
225 booke_wdt_dev.max_timeout = MAX_WDT_TIMEOUT;
226 if (booke_wdt_enabled)
227 booke_wdt_start(&booke_wdt_dev);
228
229 ret = watchdog_register_device(&booke_wdt_dev);
230
231 return ret;
232}
233
234module_init(booke_wdt_init);
235module_exit(booke_wdt_exit);
236
237MODULE_ALIAS("booke_wdt");
238MODULE_DESCRIPTION("PowerPC Book-E watchdog driver");
239MODULE_LICENSE("GPL");
240