Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6f702fce AN |
2 | /* |
3 | * txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs | |
4 | * | |
5 | * Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp> | |
6f702fce | 6 | */ |
27c766aa JP |
7 | |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
9 | ||
6f702fce AN |
10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> | |
12 | #include <linux/types.h> | |
6f702fce | 13 | #include <linux/watchdog.h> |
6f702fce | 14 | #include <linux/init.h> |
6f702fce AN |
15 | #include <linux/platform_device.h> |
16 | #include <linux/clk.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/io.h> | |
19 | #include <asm/txx9tmr.h> | |
20 | ||
b92c803e WVS |
21 | #define WD_TIMER_CCD 7 /* 1/256 */ |
22 | #define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD)) | |
23 | #define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK) | |
6f702fce AN |
24 | #define TIMER_MARGIN 60 /* Default is 60 seconds */ |
25 | ||
b92c803e WVS |
26 | static unsigned int timeout = TIMER_MARGIN; /* in seconds */ |
27 | module_param(timeout, uint, 0); | |
6f702fce AN |
28 | MODULE_PARM_DESC(timeout, |
29 | "Watchdog timeout in seconds. " | |
30 | "(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), " | |
31 | "default=" __MODULE_STRING(TIMER_MARGIN) ")"); | |
32 | ||
86a1e189 WVS |
33 | static bool nowayout = WATCHDOG_NOWAYOUT; |
34 | module_param(nowayout, bool, 0); | |
6f702fce AN |
35 | MODULE_PARM_DESC(nowayout, |
36 | "Watchdog cannot be stopped once started " | |
37 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
38 | ||
6f702fce AN |
39 | static struct txx9_tmr_reg __iomem *txx9wdt_reg; |
40 | static struct clk *txx9_imclk; | |
f8494e06 | 41 | static DEFINE_SPINLOCK(txx9_lock); |
6f702fce | 42 | |
d6245842 | 43 | static int txx9wdt_ping(struct watchdog_device *wdt_dev) |
6f702fce | 44 | { |
8dc244f7 | 45 | spin_lock(&txx9_lock); |
6f702fce | 46 | __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr); |
8dc244f7 | 47 | spin_unlock(&txx9_lock); |
d6245842 | 48 | return 0; |
6f702fce AN |
49 | } |
50 | ||
d6245842 | 51 | static int txx9wdt_start(struct watchdog_device *wdt_dev) |
6f702fce | 52 | { |
8dc244f7 | 53 | spin_lock(&txx9_lock); |
b92c803e | 54 | __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra); |
6f702fce AN |
55 | __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr); |
56 | __raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */ | |
57 | __raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG, | |
58 | &txx9wdt_reg->tcr); | |
59 | __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr); | |
8dc244f7 | 60 | spin_unlock(&txx9_lock); |
d6245842 | 61 | return 0; |
6f702fce AN |
62 | } |
63 | ||
d6245842 | 64 | static int txx9wdt_stop(struct watchdog_device *wdt_dev) |
6f702fce | 65 | { |
8dc244f7 | 66 | spin_lock(&txx9_lock); |
6f702fce AN |
67 | __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr); |
68 | __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE, | |
69 | &txx9wdt_reg->tcr); | |
8dc244f7 | 70 | spin_unlock(&txx9_lock); |
6f702fce AN |
71 | return 0; |
72 | } | |
73 | ||
d6245842 AL |
74 | static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev, |
75 | unsigned int new_timeout) | |
6f702fce | 76 | { |
b92c803e | 77 | wdt_dev->timeout = new_timeout; |
d6245842 AL |
78 | txx9wdt_stop(wdt_dev); |
79 | txx9wdt_start(wdt_dev); | |
80 | return 0; | |
6f702fce AN |
81 | } |
82 | ||
d6245842 AL |
83 | static const struct watchdog_info txx9wdt_info = { |
84 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
85 | .identity = "Hardware Watchdog for TXx9", | |
86 | }; | |
6f702fce | 87 | |
d6245842 AL |
88 | static const struct watchdog_ops txx9wdt_ops = { |
89 | .owner = THIS_MODULE, | |
90 | .start = txx9wdt_start, | |
91 | .stop = txx9wdt_stop, | |
92 | .ping = txx9wdt_ping, | |
93 | .set_timeout = txx9wdt_set_timeout, | |
6f702fce AN |
94 | }; |
95 | ||
d6245842 AL |
96 | static struct watchdog_device txx9wdt = { |
97 | .info = &txx9wdt_info, | |
98 | .ops = &txx9wdt_ops, | |
6f702fce AN |
99 | }; |
100 | ||
6f702fce AN |
101 | static int __init txx9wdt_probe(struct platform_device *dev) |
102 | { | |
6f702fce AN |
103 | int ret; |
104 | ||
105 | txx9_imclk = clk_get(NULL, "imbus_clk"); | |
106 | if (IS_ERR(txx9_imclk)) { | |
107 | ret = PTR_ERR(txx9_imclk); | |
108 | txx9_imclk = NULL; | |
109 | goto exit; | |
110 | } | |
bfb1f46f | 111 | ret = clk_prepare_enable(txx9_imclk); |
6f702fce AN |
112 | if (ret) { |
113 | clk_put(txx9_imclk); | |
114 | txx9_imclk = NULL; | |
115 | goto exit; | |
116 | } | |
117 | ||
0f0a6a28 | 118 | txx9wdt_reg = devm_platform_ioremap_resource(dev, 0); |
4c271bb6 TR |
119 | if (IS_ERR(txx9wdt_reg)) { |
120 | ret = PTR_ERR(txx9wdt_reg); | |
6f702fce AN |
121 | goto exit; |
122 | } | |
123 | ||
b92c803e WVS |
124 | if (timeout < 1 || timeout > WD_MAX_TIMEOUT) |
125 | timeout = TIMER_MARGIN; | |
126 | txx9wdt.timeout = timeout; | |
d6245842 AL |
127 | txx9wdt.min_timeout = 1; |
128 | txx9wdt.max_timeout = WD_MAX_TIMEOUT; | |
6551881c | 129 | txx9wdt.parent = &dev->dev; |
d6245842 AL |
130 | watchdog_set_nowayout(&txx9wdt, nowayout); |
131 | ||
132 | ret = watchdog_register_device(&txx9wdt); | |
133 | if (ret) | |
134 | goto exit; | |
135 | ||
27c766aa JP |
136 | pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n", |
137 | timeout, WD_MAX_TIMEOUT, nowayout); | |
6f702fce AN |
138 | |
139 | return 0; | |
6f702fce AN |
140 | exit: |
141 | if (txx9_imclk) { | |
bfb1f46f | 142 | clk_disable_unprepare(txx9_imclk); |
6f702fce AN |
143 | clk_put(txx9_imclk); |
144 | } | |
145 | return ret; | |
146 | } | |
147 | ||
148 | static int __exit txx9wdt_remove(struct platform_device *dev) | |
149 | { | |
d6245842 | 150 | watchdog_unregister_device(&txx9wdt); |
bfb1f46f | 151 | clk_disable_unprepare(txx9_imclk); |
6f702fce AN |
152 | clk_put(txx9_imclk); |
153 | return 0; | |
154 | } | |
155 | ||
168b5251 WVS |
156 | static void txx9wdt_shutdown(struct platform_device *dev) |
157 | { | |
d6245842 | 158 | txx9wdt_stop(&txx9wdt); |
168b5251 WVS |
159 | } |
160 | ||
6f702fce AN |
161 | static struct platform_driver txx9wdt_driver = { |
162 | .remove = __exit_p(txx9wdt_remove), | |
168b5251 | 163 | .shutdown = txx9wdt_shutdown, |
6f702fce AN |
164 | .driver = { |
165 | .name = "txx9wdt", | |
6f702fce AN |
166 | }, |
167 | }; | |
168 | ||
1cb9204c | 169 | module_platform_driver_probe(txx9wdt_driver, txx9wdt_probe); |
6f702fce AN |
170 | |
171 | MODULE_DESCRIPTION("TXx9 Watchdog Driver"); | |
172 | MODULE_LICENSE("GPL"); | |
f37d193c | 173 | MODULE_ALIAS("platform:txx9wdt"); |