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6f702fce AN |
1 | /* |
2 | * txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs | |
3 | * | |
4 | * Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
27c766aa JP |
10 | |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
12 | ||
6f702fce AN |
13 | #include <linux/module.h> |
14 | #include <linux/moduleparam.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/miscdevice.h> | |
17 | #include <linux/watchdog.h> | |
6f702fce | 18 | #include <linux/init.h> |
6f702fce AN |
19 | #include <linux/platform_device.h> |
20 | #include <linux/clk.h> | |
21 | #include <linux/err.h> | |
22 | #include <linux/io.h> | |
23 | #include <asm/txx9tmr.h> | |
24 | ||
b92c803e WVS |
25 | #define WD_TIMER_CCD 7 /* 1/256 */ |
26 | #define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD)) | |
27 | #define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK) | |
6f702fce AN |
28 | #define TIMER_MARGIN 60 /* Default is 60 seconds */ |
29 | ||
b92c803e WVS |
30 | static unsigned int timeout = TIMER_MARGIN; /* in seconds */ |
31 | module_param(timeout, uint, 0); | |
6f702fce AN |
32 | MODULE_PARM_DESC(timeout, |
33 | "Watchdog timeout in seconds. " | |
34 | "(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), " | |
35 | "default=" __MODULE_STRING(TIMER_MARGIN) ")"); | |
36 | ||
86a1e189 WVS |
37 | static bool nowayout = WATCHDOG_NOWAYOUT; |
38 | module_param(nowayout, bool, 0); | |
6f702fce AN |
39 | MODULE_PARM_DESC(nowayout, |
40 | "Watchdog cannot be stopped once started " | |
41 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
42 | ||
6f702fce AN |
43 | static struct txx9_tmr_reg __iomem *txx9wdt_reg; |
44 | static struct clk *txx9_imclk; | |
f8494e06 | 45 | static DEFINE_SPINLOCK(txx9_lock); |
6f702fce | 46 | |
d6245842 | 47 | static int txx9wdt_ping(struct watchdog_device *wdt_dev) |
6f702fce | 48 | { |
8dc244f7 | 49 | spin_lock(&txx9_lock); |
6f702fce | 50 | __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr); |
8dc244f7 | 51 | spin_unlock(&txx9_lock); |
d6245842 | 52 | return 0; |
6f702fce AN |
53 | } |
54 | ||
d6245842 | 55 | static int txx9wdt_start(struct watchdog_device *wdt_dev) |
6f702fce | 56 | { |
8dc244f7 | 57 | spin_lock(&txx9_lock); |
b92c803e | 58 | __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra); |
6f702fce AN |
59 | __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr); |
60 | __raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */ | |
61 | __raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG, | |
62 | &txx9wdt_reg->tcr); | |
63 | __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr); | |
8dc244f7 | 64 | spin_unlock(&txx9_lock); |
d6245842 | 65 | return 0; |
6f702fce AN |
66 | } |
67 | ||
d6245842 | 68 | static int txx9wdt_stop(struct watchdog_device *wdt_dev) |
6f702fce | 69 | { |
8dc244f7 | 70 | spin_lock(&txx9_lock); |
6f702fce AN |
71 | __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr); |
72 | __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE, | |
73 | &txx9wdt_reg->tcr); | |
8dc244f7 | 74 | spin_unlock(&txx9_lock); |
6f702fce AN |
75 | return 0; |
76 | } | |
77 | ||
d6245842 AL |
78 | static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev, |
79 | unsigned int new_timeout) | |
6f702fce | 80 | { |
b92c803e | 81 | wdt_dev->timeout = new_timeout; |
d6245842 AL |
82 | txx9wdt_stop(wdt_dev); |
83 | txx9wdt_start(wdt_dev); | |
84 | return 0; | |
6f702fce AN |
85 | } |
86 | ||
d6245842 AL |
87 | static const struct watchdog_info txx9wdt_info = { |
88 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
89 | .identity = "Hardware Watchdog for TXx9", | |
90 | }; | |
6f702fce | 91 | |
d6245842 AL |
92 | static const struct watchdog_ops txx9wdt_ops = { |
93 | .owner = THIS_MODULE, | |
94 | .start = txx9wdt_start, | |
95 | .stop = txx9wdt_stop, | |
96 | .ping = txx9wdt_ping, | |
97 | .set_timeout = txx9wdt_set_timeout, | |
6f702fce AN |
98 | }; |
99 | ||
d6245842 AL |
100 | static struct watchdog_device txx9wdt = { |
101 | .info = &txx9wdt_info, | |
102 | .ops = &txx9wdt_ops, | |
6f702fce AN |
103 | }; |
104 | ||
6f702fce AN |
105 | static int __init txx9wdt_probe(struct platform_device *dev) |
106 | { | |
107 | struct resource *res; | |
108 | int ret; | |
109 | ||
110 | txx9_imclk = clk_get(NULL, "imbus_clk"); | |
111 | if (IS_ERR(txx9_imclk)) { | |
112 | ret = PTR_ERR(txx9_imclk); | |
113 | txx9_imclk = NULL; | |
114 | goto exit; | |
115 | } | |
116 | ret = clk_enable(txx9_imclk); | |
117 | if (ret) { | |
118 | clk_put(txx9_imclk); | |
119 | txx9_imclk = NULL; | |
120 | goto exit; | |
121 | } | |
122 | ||
123 | res = platform_get_resource(dev, IORESOURCE_MEM, 0); | |
d6245842 AL |
124 | txx9wdt_reg = devm_request_and_ioremap(&dev->dev, res); |
125 | if (!txx9wdt_reg) { | |
126 | ret = -EBUSY; | |
6f702fce AN |
127 | goto exit; |
128 | } | |
129 | ||
b92c803e WVS |
130 | if (timeout < 1 || timeout > WD_MAX_TIMEOUT) |
131 | timeout = TIMER_MARGIN; | |
132 | txx9wdt.timeout = timeout; | |
d6245842 AL |
133 | txx9wdt.min_timeout = 1; |
134 | txx9wdt.max_timeout = WD_MAX_TIMEOUT; | |
135 | watchdog_set_nowayout(&txx9wdt, nowayout); | |
136 | ||
137 | ret = watchdog_register_device(&txx9wdt); | |
138 | if (ret) | |
139 | goto exit; | |
140 | ||
27c766aa JP |
141 | pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n", |
142 | timeout, WD_MAX_TIMEOUT, nowayout); | |
6f702fce AN |
143 | |
144 | return 0; | |
6f702fce AN |
145 | exit: |
146 | if (txx9_imclk) { | |
147 | clk_disable(txx9_imclk); | |
148 | clk_put(txx9_imclk); | |
149 | } | |
150 | return ret; | |
151 | } | |
152 | ||
153 | static int __exit txx9wdt_remove(struct platform_device *dev) | |
154 | { | |
d6245842 | 155 | watchdog_unregister_device(&txx9wdt); |
6f702fce AN |
156 | clk_disable(txx9_imclk); |
157 | clk_put(txx9_imclk); | |
158 | return 0; | |
159 | } | |
160 | ||
168b5251 WVS |
161 | static void txx9wdt_shutdown(struct platform_device *dev) |
162 | { | |
d6245842 | 163 | txx9wdt_stop(&txx9wdt); |
168b5251 WVS |
164 | } |
165 | ||
6f702fce AN |
166 | static struct platform_driver txx9wdt_driver = { |
167 | .remove = __exit_p(txx9wdt_remove), | |
168b5251 | 168 | .shutdown = txx9wdt_shutdown, |
6f702fce AN |
169 | .driver = { |
170 | .name = "txx9wdt", | |
171 | .owner = THIS_MODULE, | |
172 | }, | |
173 | }; | |
174 | ||
175 | static int __init watchdog_init(void) | |
176 | { | |
177 | return platform_driver_probe(&txx9wdt_driver, txx9wdt_probe); | |
178 | } | |
179 | ||
180 | static void __exit watchdog_exit(void) | |
181 | { | |
182 | platform_driver_unregister(&txx9wdt_driver); | |
183 | } | |
184 | ||
185 | module_init(watchdog_init); | |
186 | module_exit(watchdog_exit); | |
187 | ||
188 | MODULE_DESCRIPTION("TXx9 Watchdog Driver"); | |
189 | MODULE_LICENSE("GPL"); | |
190 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
f37d193c | 191 | MODULE_ALIAS("platform:txx9wdt"); |