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f0fcbdbf XD |
1 | /* |
2 | * Watchdog driver for CSR SiRFprimaII and SiRFatlasVI | |
3 | * | |
4 | * Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company. | |
5 | * | |
6 | * Licensed under GPLv2 or later. | |
7 | */ | |
8 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/watchdog.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/moduleparam.h> | |
13 | #include <linux/of.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/uaccess.h> | |
16 | ||
b0df38dd UKK |
17 | #define CLOCK_FREQ 1000000 |
18 | ||
f0fcbdbf XD |
19 | #define SIRFSOC_TIMER_COUNTER_LO 0x0000 |
20 | #define SIRFSOC_TIMER_MATCH_0 0x0008 | |
21 | #define SIRFSOC_TIMER_INT_EN 0x0024 | |
22 | #define SIRFSOC_TIMER_WATCHDOG_EN 0x0028 | |
23 | #define SIRFSOC_TIMER_LATCH 0x0030 | |
24 | #define SIRFSOC_TIMER_LATCHED_LO 0x0034 | |
25 | ||
26 | #define SIRFSOC_TIMER_WDT_INDEX 5 | |
27 | ||
28 | #define SIRFSOC_WDT_MIN_TIMEOUT 30 /* 30 secs */ | |
29 | #define SIRFSOC_WDT_MAX_TIMEOUT (10 * 60) /* 10 mins */ | |
30 | #define SIRFSOC_WDT_DEFAULT_TIMEOUT 30 /* 30 secs */ | |
31 | ||
32 | static unsigned int timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT; | |
33 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
34 | ||
35 | module_param(timeout, uint, 0); | |
36 | module_param(nowayout, bool, 0); | |
37 | ||
38 | MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)"); | |
39 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | |
40 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
41 | ||
42 | static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd) | |
43 | { | |
44 | u32 counter, match; | |
45 | void __iomem *wdt_base; | |
46 | int time_left; | |
47 | ||
48 | wdt_base = watchdog_get_drvdata(wdd); | |
49 | counter = readl(wdt_base + SIRFSOC_TIMER_COUNTER_LO); | |
50 | match = readl(wdt_base + | |
51 | SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2)); | |
52 | ||
53 | time_left = match - counter; | |
54 | ||
b0df38dd | 55 | return time_left / CLOCK_FREQ; |
f0fcbdbf XD |
56 | } |
57 | ||
58 | static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd) | |
59 | { | |
60 | u32 counter, timeout_ticks; | |
61 | void __iomem *wdt_base; | |
62 | ||
b0df38dd | 63 | timeout_ticks = wdd->timeout * CLOCK_FREQ; |
f0fcbdbf XD |
64 | wdt_base = watchdog_get_drvdata(wdd); |
65 | ||
66 | /* Enable the latch before reading the LATCH_LO register */ | |
67 | writel(1, wdt_base + SIRFSOC_TIMER_LATCH); | |
68 | ||
69 | /* Set the TO value */ | |
70 | counter = readl(wdt_base + SIRFSOC_TIMER_LATCHED_LO); | |
71 | ||
72 | counter += timeout_ticks; | |
73 | ||
74 | writel(counter, wdt_base + | |
75 | SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2)); | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static int sirfsoc_wdt_enable(struct watchdog_device *wdd) | |
81 | { | |
82 | void __iomem *wdt_base = watchdog_get_drvdata(wdd); | |
83 | sirfsoc_wdt_updatetimeout(wdd); | |
84 | ||
85 | /* | |
86 | * NOTE: If interrupt is not enabled | |
87 | * then WD-Reset doesn't get generated at all. | |
88 | */ | |
89 | writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN) | |
90 | | (1 << SIRFSOC_TIMER_WDT_INDEX), | |
91 | wdt_base + SIRFSOC_TIMER_INT_EN); | |
92 | writel(1, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN); | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
97 | static int sirfsoc_wdt_disable(struct watchdog_device *wdd) | |
98 | { | |
99 | void __iomem *wdt_base = watchdog_get_drvdata(wdd); | |
100 | ||
101 | writel(0, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN); | |
102 | writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN) | |
103 | & (~(1 << SIRFSOC_TIMER_WDT_INDEX)), | |
104 | wdt_base + SIRFSOC_TIMER_INT_EN); | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
109 | static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) | |
110 | { | |
111 | wdd->timeout = to; | |
112 | sirfsoc_wdt_updatetimeout(wdd); | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) | |
118 | ||
119 | static const struct watchdog_info sirfsoc_wdt_ident = { | |
120 | .options = OPTIONS, | |
121 | .firmware_version = 0, | |
122 | .identity = "SiRFSOC Watchdog", | |
123 | }; | |
124 | ||
125 | static struct watchdog_ops sirfsoc_wdt_ops = { | |
126 | .owner = THIS_MODULE, | |
127 | .start = sirfsoc_wdt_enable, | |
128 | .stop = sirfsoc_wdt_disable, | |
129 | .get_timeleft = sirfsoc_wdt_gettimeleft, | |
130 | .ping = sirfsoc_wdt_updatetimeout, | |
131 | .set_timeout = sirfsoc_wdt_settimeout, | |
132 | }; | |
133 | ||
134 | static struct watchdog_device sirfsoc_wdd = { | |
135 | .info = &sirfsoc_wdt_ident, | |
136 | .ops = &sirfsoc_wdt_ops, | |
137 | .timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT, | |
138 | .min_timeout = SIRFSOC_WDT_MIN_TIMEOUT, | |
139 | .max_timeout = SIRFSOC_WDT_MAX_TIMEOUT, | |
140 | }; | |
141 | ||
142 | static int sirfsoc_wdt_probe(struct platform_device *pdev) | |
143 | { | |
144 | struct resource *res; | |
145 | int ret; | |
146 | void __iomem *base; | |
147 | ||
148 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
149 | base = devm_ioremap_resource(&pdev->dev, res); | |
150 | if (IS_ERR(base)) | |
151 | return PTR_ERR(base); | |
152 | ||
153 | watchdog_set_drvdata(&sirfsoc_wdd, base); | |
154 | ||
155 | watchdog_init_timeout(&sirfsoc_wdd, timeout, &pdev->dev); | |
156 | watchdog_set_nowayout(&sirfsoc_wdd, nowayout); | |
157 | ||
158 | ret = watchdog_register_device(&sirfsoc_wdd); | |
159 | if (ret) | |
160 | return ret; | |
161 | ||
162 | platform_set_drvdata(pdev, &sirfsoc_wdd); | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | static void sirfsoc_wdt_shutdown(struct platform_device *pdev) | |
168 | { | |
169 | struct watchdog_device *wdd = platform_get_drvdata(pdev); | |
170 | ||
171 | sirfsoc_wdt_disable(wdd); | |
172 | } | |
173 | ||
174 | static int sirfsoc_wdt_remove(struct platform_device *pdev) | |
175 | { | |
176 | sirfsoc_wdt_shutdown(pdev); | |
177 | return 0; | |
178 | } | |
179 | ||
180 | #ifdef CONFIG_PM_SLEEP | |
181 | static int sirfsoc_wdt_suspend(struct device *dev) | |
182 | { | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static int sirfsoc_wdt_resume(struct device *dev) | |
187 | { | |
188 | struct watchdog_device *wdd = dev_get_drvdata(dev); | |
189 | ||
190 | /* | |
191 | * NOTE: Since timer controller registers settings are saved | |
192 | * and restored back by the timer-prima2.c, so we need not | |
193 | * update WD settings except refreshing timeout. | |
194 | */ | |
195 | sirfsoc_wdt_updatetimeout(wdd); | |
196 | ||
197 | return 0; | |
198 | } | |
199 | #endif | |
200 | ||
201 | static SIMPLE_DEV_PM_OPS(sirfsoc_wdt_pm_ops, | |
202 | sirfsoc_wdt_suspend, sirfsoc_wdt_resume); | |
203 | ||
204 | static const struct of_device_id sirfsoc_wdt_of_match[] = { | |
205 | { .compatible = "sirf,prima2-tick"}, | |
206 | {}, | |
207 | }; | |
208 | MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match); | |
209 | ||
210 | static struct platform_driver sirfsoc_wdt_driver = { | |
211 | .driver = { | |
212 | .name = "sirfsoc-wdt", | |
f0fcbdbf | 213 | .pm = &sirfsoc_wdt_pm_ops, |
15edd9ee | 214 | .of_match_table = sirfsoc_wdt_of_match, |
f0fcbdbf XD |
215 | }, |
216 | .probe = sirfsoc_wdt_probe, | |
217 | .remove = sirfsoc_wdt_remove, | |
218 | .shutdown = sirfsoc_wdt_shutdown, | |
219 | }; | |
220 | module_platform_driver(sirfsoc_wdt_driver); | |
221 | ||
222 | MODULE_DESCRIPTION("SiRF SoC watchdog driver"); | |
223 | MODULE_AUTHOR("Xianglong Du <Xianglong.Du@csr.com>"); | |
224 | MODULE_LICENSE("GPL v2"); | |
225 | MODULE_ALIAS("platform:sirfsoc-wdt"); |