OpenWrt – Blame information for rev 1
?pathlinks?
Rev | Author | Line No. | Line |
---|---|---|---|
1 | office | 1 | /* |
2 | * Moschip MCS814x Watchdog driver |
||
3 | * |
||
4 | * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org> |
||
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 as published by |
||
8 | * the Free Software Foundation; either version 2 of the License, or |
||
9 | * (at your option) any later version. |
||
10 | * |
||
11 | * This program is distributed in the hope that it will be useful, |
||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
||
14 | * GNU General Public License for more details. |
||
15 | * |
||
16 | * You should have received a copy of the GNU General Public License |
||
17 | * along with this program; if not, write to the Free Software |
||
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
||
19 | */ |
||
20 | |||
21 | #include <linux/module.h> |
||
22 | #include <linux/slab.h> |
||
23 | #include <linux/init.h> |
||
24 | #include <linux/platform_device.h> |
||
25 | #include <linux/miscdevice.h> |
||
26 | #include <linux/watchdog.h> |
||
27 | #include <linux/io.h> |
||
28 | #include <linux/err.h> |
||
29 | #include <linux/clk.h> |
||
30 | #include <linux/of.h> |
||
31 | |||
32 | #define WDT_COUNT 0x00 |
||
33 | #define WDT_CTRL 0x04 |
||
34 | #define WDT_CTRL_EN 0x1 |
||
35 | |||
36 | /* watchdog frequency */ |
||
37 | #define WDT_MAX_VALUE (0xffffffff) |
||
38 | |||
39 | struct mcs814x_wdt { |
||
40 | void __iomem *regs; |
||
41 | spinlock_t lock; |
||
42 | struct watchdog_device wdt_dev; |
||
43 | struct clk *clk; |
||
44 | }; |
||
45 | |||
46 | static int mcs814x_wdt_start(struct watchdog_device *dev) |
||
47 | { |
||
48 | struct mcs814x_wdt *wdt = watchdog_get_drvdata(dev); |
||
49 | u32 reg; |
||
50 | |||
51 | spin_lock(&wdt->lock); |
||
52 | reg = readl_relaxed(wdt->regs + WDT_CTRL); |
||
53 | reg |= WDT_CTRL_EN; |
||
54 | writel_relaxed(reg, wdt->regs + WDT_CTRL); |
||
55 | spin_unlock(&wdt->lock); |
||
56 | |||
57 | return 0; |
||
58 | } |
||
59 | |||
60 | static int mcs814x_wdt_stop(struct watchdog_device *dev) |
||
61 | { |
||
62 | struct mcs814x_wdt *wdt = watchdog_get_drvdata(dev); |
||
63 | u32 reg; |
||
64 | |||
65 | spin_lock(&wdt->lock); |
||
66 | reg = readl_relaxed(wdt->regs + WDT_CTRL); |
||
67 | reg &= ~WDT_CTRL_EN; |
||
68 | writel_relaxed(reg, wdt->regs + WDT_CTRL); |
||
69 | spin_unlock(&wdt->lock); |
||
70 | |||
71 | return 0; |
||
72 | } |
||
73 | |||
74 | static int mcs814x_wdt_set_timeout(struct watchdog_device *dev, |
||
75 | unsigned int new_timeout) |
||
76 | { |
||
77 | struct mcs814x_wdt *wdt = watchdog_get_drvdata(dev); |
||
78 | |||
79 | spin_lock(&wdt->lock); |
||
80 | /* watchdog counts upward and rollover (0xfffffff -> 0) |
||
81 | * triggers the reboot |
||
82 | */ |
||
83 | writel_relaxed(WDT_MAX_VALUE - (new_timeout * clk_get_rate(wdt->clk)), |
||
84 | wdt->regs + WDT_COUNT); |
||
85 | spin_unlock(&wdt->lock); |
||
86 | |||
87 | return 0; |
||
88 | } |
||
89 | |||
90 | static int mcs814x_wdt_ping(struct watchdog_device *dev) |
||
91 | { |
||
92 | /* restart the watchdog */ |
||
93 | mcs814x_wdt_stop(dev); |
||
94 | mcs814x_wdt_set_timeout(dev, dev->timeout); |
||
95 | mcs814x_wdt_start(dev); |
||
96 | |||
97 | return 0; |
||
98 | } |
||
99 | |||
100 | static const struct watchdog_info mcs814x_wdt_ident = { |
||
101 | .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | |
||
102 | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, |
||
103 | .identity = "MCS814x Watchdog", |
||
104 | }; |
||
105 | |||
106 | static struct watchdog_ops mcs814x_wdt_ops = { |
||
107 | .owner = THIS_MODULE, |
||
108 | .start = mcs814x_wdt_start, |
||
109 | .stop = mcs814x_wdt_stop, |
||
110 | .set_timeout = mcs814x_wdt_set_timeout, |
||
111 | .ping = mcs814x_wdt_ping, |
||
112 | }; |
||
113 | |||
114 | static int mcs814x_wdt_probe(struct platform_device *pdev) |
||
115 | { |
||
116 | struct resource *res; |
||
117 | struct mcs814x_wdt *wdt; |
||
118 | int ret; |
||
119 | struct clk *clk; |
||
120 | |||
121 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
||
122 | if (!res) |
||
123 | return -ENODEV; |
||
124 | |||
125 | clk = clk_get(NULL, "wdt"); |
||
126 | if (IS_ERR_OR_NULL(clk)) { |
||
127 | dev_err(&pdev->dev, "failed to get watchdog clock\n"); |
||
128 | return PTR_ERR(clk); |
||
129 | } |
||
130 | |||
131 | wdt = kzalloc(sizeof(*wdt), GFP_KERNEL); |
||
132 | if (!wdt) { |
||
133 | ret = -ENOMEM; |
||
134 | goto out_clk; |
||
135 | } |
||
136 | |||
137 | spin_lock_init(&wdt->lock); |
||
138 | wdt->clk = clk; |
||
139 | wdt->wdt_dev.info = &mcs814x_wdt_ident; |
||
140 | wdt->wdt_dev.ops = &mcs814x_wdt_ops; |
||
141 | wdt->wdt_dev.min_timeout = 1; |
||
142 | /* approximately 10995 secs */ |
||
143 | wdt->wdt_dev.max_timeout = (WDT_MAX_VALUE / clk_get_rate(clk)); |
||
144 | |||
145 | platform_set_drvdata(pdev, wdt); |
||
146 | |||
147 | /* only ioremap registers, because the register is shared */ |
||
148 | wdt->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res)); |
||
149 | if (!wdt->regs) { |
||
150 | ret = -ENOMEM; |
||
151 | goto out; |
||
152 | } |
||
153 | |||
154 | watchdog_set_drvdata(&wdt->wdt_dev, wdt); |
||
155 | |||
156 | ret = watchdog_register_device(&wdt->wdt_dev); |
||
157 | if (ret) { |
||
158 | dev_err(&pdev->dev, "cannot register watchdog: %d\n", ret); |
||
159 | goto out; |
||
160 | } |
||
161 | |||
162 | dev_info(&pdev->dev, "registered\n"); |
||
163 | return 0; |
||
164 | |||
165 | out: |
||
166 | platform_set_drvdata(pdev, NULL); |
||
167 | kfree(wdt); |
||
168 | out_clk: |
||
169 | clk_put(clk); |
||
170 | return ret; |
||
171 | } |
||
172 | |||
173 | static int mcs814x_wdt_remove(struct platform_device *pdev) |
||
174 | { |
||
175 | struct mcs814x_wdt *wdt = platform_get_drvdata(pdev); |
||
176 | |||
177 | clk_put(wdt->clk); |
||
178 | watchdog_unregister_device(&wdt->wdt_dev); |
||
179 | watchdog_set_drvdata(&wdt->wdt_dev, NULL); |
||
180 | kfree(wdt); |
||
181 | platform_set_drvdata(pdev, NULL); |
||
182 | |||
183 | return 0; |
||
184 | } |
||
185 | |||
186 | static const struct of_device_id mcs814x_wdt_ids[] = { |
||
187 | { .compatible = "moschip,mcs814x-wdt", }, |
||
188 | { /* sentinel */ }, |
||
189 | }; |
||
190 | |||
191 | static struct platform_driver mcs814x_wdt_driver = { |
||
192 | .driver = { |
||
193 | .name = "mcs814x-wdt", |
||
194 | .owner = THIS_MODULE, |
||
195 | .of_match_table = mcs814x_wdt_ids, |
||
196 | }, |
||
197 | .probe = mcs814x_wdt_probe, |
||
198 | .remove = mcs814x_wdt_remove, |
||
199 | }; |
||
200 | |||
201 | module_platform_driver(mcs814x_wdt_driver); |
||
202 | |||
203 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); |
||
204 | MODULE_DESCRIPTION("Moschip MCS814x Watchdog driver"); |
||
205 | MODULE_LICENSE("GPL"); |
||
206 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
||
207 | MODULE_ALIAS("platform:mcs814x-wdt"); |