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e3c21e08 AL |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * Watchdog driver for TQMx86 PLD. | |
4 | * | |
5 | * The watchdog supports power of 2 timeouts from 1 to 4096sec. | |
6 | * Once started, it cannot be stopped. | |
7 | * | |
8 | * Based on the vendor code written by Vadim V.Vlasov | |
9 | * <vvlasov@dev.rtsoft.ru> | |
10 | */ | |
11 | ||
12 | #include <linux/io.h> | |
13 | #include <linux/log2.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/timer.h> | |
17 | #include <linux/watchdog.h> | |
18 | ||
19 | /* default timeout (secs) */ | |
20 | #define WDT_TIMEOUT 32 | |
21 | ||
22 | static unsigned int timeout; | |
23 | module_param(timeout, uint, 0); | |
24 | MODULE_PARM_DESC(timeout, | |
25 | "Watchdog timeout in seconds. (1<=timeout<=4096, default=" | |
26 | __MODULE_STRING(WDT_TIMEOUT) ")"); | |
27 | struct tqmx86_wdt { | |
28 | struct watchdog_device wdd; | |
29 | void __iomem *io_base; | |
30 | }; | |
31 | ||
32 | #define TQMX86_WDCFG 0x00 /* Watchdog Configuration Register */ | |
33 | #define TQMX86_WDCS 0x01 /* Watchdog Config/Status Register */ | |
34 | ||
35 | static int tqmx86_wdt_start(struct watchdog_device *wdd) | |
36 | { | |
37 | struct tqmx86_wdt *priv = watchdog_get_drvdata(wdd); | |
38 | ||
39 | iowrite8(0x81, priv->io_base + TQMX86_WDCS); | |
40 | ||
41 | return 0; | |
42 | } | |
43 | ||
44 | static int tqmx86_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) | |
45 | { | |
46 | struct tqmx86_wdt *priv = watchdog_get_drvdata(wdd); | |
47 | u8 val; | |
48 | ||
49 | t = roundup_pow_of_two(t); | |
50 | val = ilog2(t) | 0x90; | |
51 | val += 3; /* values 0,1,2 correspond to 0.125,0.25,0.5s timeouts */ | |
52 | iowrite8(val, priv->io_base + TQMX86_WDCFG); | |
53 | ||
54 | wdd->timeout = t; | |
55 | ||
56 | return 0; | |
57 | } | |
58 | ||
59 | static const struct watchdog_info tqmx86_wdt_info = { | |
60 | .options = WDIOF_SETTIMEOUT | | |
61 | WDIOF_KEEPALIVEPING, | |
62 | .identity = "TQMx86 Watchdog", | |
63 | }; | |
64 | ||
625e407c | 65 | static const struct watchdog_ops tqmx86_wdt_ops = { |
e3c21e08 AL |
66 | .owner = THIS_MODULE, |
67 | .start = tqmx86_wdt_start, | |
68 | .set_timeout = tqmx86_wdt_set_timeout, | |
69 | }; | |
70 | ||
71 | static int tqmx86_wdt_probe(struct platform_device *pdev) | |
72 | { | |
09fb6d01 | 73 | struct device *dev = &pdev->dev; |
e3c21e08 AL |
74 | struct tqmx86_wdt *priv; |
75 | struct resource *res; | |
76 | int err; | |
77 | ||
09fb6d01 | 78 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
e3c21e08 AL |
79 | if (!priv) |
80 | return -ENOMEM; | |
81 | ||
82 | res = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
4a22fc53 DC |
83 | if (!res) |
84 | return -ENODEV; | |
e3c21e08 | 85 | |
09fb6d01 | 86 | priv->io_base = devm_ioport_map(dev, res->start, resource_size(res)); |
4a22fc53 DC |
87 | if (!priv->io_base) |
88 | return -ENOMEM; | |
e3c21e08 AL |
89 | |
90 | watchdog_set_drvdata(&priv->wdd, priv); | |
91 | ||
09fb6d01 | 92 | priv->wdd.parent = dev; |
e3c21e08 AL |
93 | priv->wdd.info = &tqmx86_wdt_info; |
94 | priv->wdd.ops = &tqmx86_wdt_ops; | |
95 | priv->wdd.min_timeout = 1; | |
96 | priv->wdd.max_timeout = 4096; | |
97 | priv->wdd.max_hw_heartbeat_ms = 4096*1000; | |
98 | priv->wdd.timeout = WDT_TIMEOUT; | |
99 | ||
09fb6d01 | 100 | watchdog_init_timeout(&priv->wdd, timeout, dev); |
e3c21e08 AL |
101 | watchdog_set_nowayout(&priv->wdd, WATCHDOG_NOWAYOUT); |
102 | ||
103 | tqmx86_wdt_set_timeout(&priv->wdd, priv->wdd.timeout); | |
104 | ||
09fb6d01 | 105 | err = devm_watchdog_register_device(dev, &priv->wdd); |
e3c21e08 AL |
106 | if (err) |
107 | return err; | |
108 | ||
09fb6d01 | 109 | dev_info(dev, "TQMx86 watchdog\n"); |
e3c21e08 AL |
110 | |
111 | return 0; | |
112 | } | |
113 | ||
114 | static struct platform_driver tqmx86_wdt_driver = { | |
115 | .driver = { | |
116 | .name = "tqmx86-wdt", | |
117 | }, | |
118 | .probe = tqmx86_wdt_probe, | |
119 | }; | |
120 | ||
121 | module_platform_driver(tqmx86_wdt_driver); | |
122 | ||
123 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); | |
124 | MODULE_DESCRIPTION("TQMx86 Watchdog"); | |
125 | MODULE_ALIAS("platform:tqmx86-wdt"); | |
126 | MODULE_LICENSE("GPL"); |