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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1d8565ee YL |
2 | /* |
3 | * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com> | |
1d8565ee YL |
4 | */ |
5 | ||
6 | #include <linux/clk.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/platform_device.h> | |
9 | #include <linux/watchdog.h> | |
10 | #include <loongson1.h> | |
11 | ||
12 | #define DEFAULT_HEARTBEAT 30 | |
13 | ||
14 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
15 | module_param(nowayout, bool, 0444); | |
16 | ||
17 | static unsigned int heartbeat; | |
18 | module_param(heartbeat, uint, 0444); | |
19 | ||
20 | struct ls1x_wdt_drvdata { | |
21 | void __iomem *base; | |
22 | struct clk *clk; | |
23 | unsigned long clk_rate; | |
24 | struct watchdog_device wdt; | |
25 | }; | |
26 | ||
27 | static int ls1x_wdt_ping(struct watchdog_device *wdt_dev) | |
28 | { | |
29 | struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); | |
30 | ||
31 | writel(0x1, drvdata->base + WDT_SET); | |
32 | ||
33 | return 0; | |
34 | } | |
35 | ||
36 | static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
37 | unsigned int timeout) | |
38 | { | |
39 | struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); | |
40 | unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000; | |
41 | unsigned int counts; | |
42 | ||
43 | wdt_dev->timeout = timeout; | |
44 | ||
45 | counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat); | |
46 | writel(counts, drvdata->base + WDT_TIMER); | |
47 | ||
48 | return 0; | |
49 | } | |
50 | ||
51 | static int ls1x_wdt_start(struct watchdog_device *wdt_dev) | |
52 | { | |
53 | struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); | |
54 | ||
55 | writel(0x1, drvdata->base + WDT_EN); | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | static int ls1x_wdt_stop(struct watchdog_device *wdt_dev) | |
61 | { | |
62 | struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); | |
63 | ||
64 | writel(0x0, drvdata->base + WDT_EN); | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | static const struct watchdog_info ls1x_wdt_info = { | |
70 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
71 | .identity = "Loongson1 Watchdog", | |
72 | }; | |
73 | ||
74 | static const struct watchdog_ops ls1x_wdt_ops = { | |
75 | .owner = THIS_MODULE, | |
76 | .start = ls1x_wdt_start, | |
77 | .stop = ls1x_wdt_stop, | |
78 | .ping = ls1x_wdt_ping, | |
79 | .set_timeout = ls1x_wdt_set_timeout, | |
80 | }; | |
81 | ||
fd56d6c9 GR |
82 | static void ls1x_clk_disable_unprepare(void *data) |
83 | { | |
84 | clk_disable_unprepare(data); | |
85 | } | |
86 | ||
1d8565ee YL |
87 | static int ls1x_wdt_probe(struct platform_device *pdev) |
88 | { | |
fd56d6c9 | 89 | struct device *dev = &pdev->dev; |
1d8565ee YL |
90 | struct ls1x_wdt_drvdata *drvdata; |
91 | struct watchdog_device *ls1x_wdt; | |
92 | unsigned long clk_rate; | |
1d8565ee YL |
93 | int err; |
94 | ||
fd56d6c9 | 95 | drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); |
1d8565ee YL |
96 | if (!drvdata) |
97 | return -ENOMEM; | |
98 | ||
0f0a6a28 | 99 | drvdata->base = devm_platform_ioremap_resource(pdev, 0); |
1d8565ee YL |
100 | if (IS_ERR(drvdata->base)) |
101 | return PTR_ERR(drvdata->base); | |
102 | ||
fd56d6c9 | 103 | drvdata->clk = devm_clk_get(dev, pdev->name); |
1d8565ee YL |
104 | if (IS_ERR(drvdata->clk)) |
105 | return PTR_ERR(drvdata->clk); | |
106 | ||
107 | err = clk_prepare_enable(drvdata->clk); | |
108 | if (err) { | |
fd56d6c9 | 109 | dev_err(dev, "clk enable failed\n"); |
1d8565ee YL |
110 | return err; |
111 | } | |
fd56d6c9 GR |
112 | err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare, |
113 | drvdata->clk); | |
114 | if (err) | |
115 | return err; | |
1d8565ee YL |
116 | |
117 | clk_rate = clk_get_rate(drvdata->clk); | |
fd56d6c9 GR |
118 | if (!clk_rate) |
119 | return -EINVAL; | |
1d8565ee YL |
120 | drvdata->clk_rate = clk_rate; |
121 | ||
122 | ls1x_wdt = &drvdata->wdt; | |
123 | ls1x_wdt->info = &ls1x_wdt_info; | |
124 | ls1x_wdt->ops = &ls1x_wdt_ops; | |
125 | ls1x_wdt->timeout = DEFAULT_HEARTBEAT; | |
126 | ls1x_wdt->min_timeout = 1; | |
127 | ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000; | |
fd56d6c9 | 128 | ls1x_wdt->parent = dev; |
1d8565ee | 129 | |
fd56d6c9 | 130 | watchdog_init_timeout(ls1x_wdt, heartbeat, dev); |
1d8565ee YL |
131 | watchdog_set_nowayout(ls1x_wdt, nowayout); |
132 | watchdog_set_drvdata(ls1x_wdt, drvdata); | |
133 | ||
fd56d6c9 | 134 | err = devm_watchdog_register_device(dev, &drvdata->wdt); |
1d8565ee | 135 | if (err) { |
fd56d6c9 GR |
136 | dev_err(dev, "failed to register watchdog device\n"); |
137 | return err; | |
1d8565ee YL |
138 | } |
139 | ||
140 | platform_set_drvdata(pdev, drvdata); | |
141 | ||
fd56d6c9 | 142 | dev_info(dev, "Loongson1 Watchdog driver registered\n"); |
1d8565ee YL |
143 | |
144 | return 0; | |
145 | } | |
146 | ||
147 | static struct platform_driver ls1x_wdt_driver = { | |
148 | .probe = ls1x_wdt_probe, | |
1d8565ee YL |
149 | .driver = { |
150 | .name = "ls1x-wdt", | |
151 | }, | |
152 | }; | |
153 | ||
154 | module_platform_driver(ls1x_wdt_driver); | |
155 | ||
156 | MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>"); | |
157 | MODULE_DESCRIPTION("Loongson1 Watchdog Driver"); | |
158 | MODULE_LICENSE("GPL"); |