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20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/fs.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/timer.h>
26#include <linux/of_address.h>
27#include <linux/of_platform.h>
28#include <linux/module.h>
29#include <linux/watchdog.h>
30#include <linux/io.h>
31#include <linux/uaccess.h>
32#include <sysdev/fsl_soc.h>
33
34struct mpc8xxx_wdt {
35 __be32 res0;
36 __be32 swcrr;
37#define SWCRR_SWTC 0xFFFF0000
38#define SWCRR_SWEN 0x00000004
39#define SWCRR_SWRI 0x00000002
40#define SWCRR_SWPR 0x00000001
41 __be32 swcnr;
42 u8 res1[2];
43 __be16 swsrr;
44 u8 res2[0xF0];
45};
46
47struct mpc8xxx_wdt_type {
48 int prescaler;
49 bool hw_enabled;
50};
51
52struct mpc8xxx_wdt_ddata {
53 struct mpc8xxx_wdt __iomem *base;
54 struct watchdog_device wdd;
55 struct timer_list timer;
56 spinlock_t lock;
57};
58
59static u16 timeout = 0xffff;
60module_param(timeout, ushort, 0);
61MODULE_PARM_DESC(timeout,
62 "Watchdog timeout in ticks. (0<timeout<65536, default=65535)");
63
64static bool reset = 1;
65module_param(reset, bool, 0);
66MODULE_PARM_DESC(reset,
67 "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
68
69static bool nowayout = WATCHDOG_NOWAYOUT;
70module_param(nowayout, bool, 0);
71MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
72 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
73
74static void mpc8xxx_wdt_keepalive(struct mpc8xxx_wdt_ddata *ddata)
75{
76
77 spin_lock(&ddata->lock);
78 out_be16(&ddata->base->swsrr, 0x556c);
79 out_be16(&ddata->base->swsrr, 0xaa39);
80 spin_unlock(&ddata->lock);
81}
82
83static void mpc8xxx_wdt_timer_ping(unsigned long arg)
84{
85 struct mpc8xxx_wdt_ddata *ddata = (void *)arg;
86
87 mpc8xxx_wdt_keepalive(ddata);
88
89 mod_timer(&ddata->timer, jiffies + HZ * ddata->wdd.timeout / 2);
90}
91
92static int mpc8xxx_wdt_start(struct watchdog_device *w)
93{
94 struct mpc8xxx_wdt_ddata *ddata =
95 container_of(w, struct mpc8xxx_wdt_ddata, wdd);
96
97 u32 tmp = SWCRR_SWEN | SWCRR_SWPR;
98
99
100 if (reset)
101 tmp |= SWCRR_SWRI;
102
103 tmp |= timeout << 16;
104
105 out_be32(&ddata->base->swcrr, tmp);
106
107 del_timer_sync(&ddata->timer);
108
109 return 0;
110}
111
112static int mpc8xxx_wdt_ping(struct watchdog_device *w)
113{
114 struct mpc8xxx_wdt_ddata *ddata =
115 container_of(w, struct mpc8xxx_wdt_ddata, wdd);
116
117 mpc8xxx_wdt_keepalive(ddata);
118 return 0;
119}
120
121static int mpc8xxx_wdt_stop(struct watchdog_device *w)
122{
123 struct mpc8xxx_wdt_ddata *ddata =
124 container_of(w, struct mpc8xxx_wdt_ddata, wdd);
125
126 mod_timer(&ddata->timer, jiffies);
127 return 0;
128}
129
130static struct watchdog_info mpc8xxx_wdt_info = {
131 .options = WDIOF_KEEPALIVEPING,
132 .firmware_version = 1,
133 .identity = "MPC8xxx",
134};
135
136static struct watchdog_ops mpc8xxx_wdt_ops = {
137 .owner = THIS_MODULE,
138 .start = mpc8xxx_wdt_start,
139 .ping = mpc8xxx_wdt_ping,
140 .stop = mpc8xxx_wdt_stop,
141};
142
143static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
144{
145 int ret;
146 struct resource *res;
147 const struct mpc8xxx_wdt_type *wdt_type;
148 struct mpc8xxx_wdt_ddata *ddata;
149 u32 freq = fsl_get_sys_freq();
150 bool enabled;
151 unsigned int timeout_sec;
152
153 wdt_type = of_device_get_match_data(&ofdev->dev);
154 if (!wdt_type)
155 return -EINVAL;
156
157 if (!freq || freq == -1)
158 return -EINVAL;
159
160 ddata = devm_kzalloc(&ofdev->dev, sizeof(*ddata), GFP_KERNEL);
161 if (!ddata)
162 return -ENOMEM;
163
164 res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
165 ddata->base = devm_ioremap_resource(&ofdev->dev, res);
166 if (IS_ERR(ddata->base))
167 return PTR_ERR(ddata->base);
168
169 enabled = in_be32(&ddata->base->swcrr) & SWCRR_SWEN;
170 if (!enabled && wdt_type->hw_enabled) {
171 pr_info("could not be enabled in software\n");
172 return -ENODEV;
173 }
174
175 spin_lock_init(&ddata->lock);
176 setup_timer(&ddata->timer, mpc8xxx_wdt_timer_ping,
177 (unsigned long)ddata);
178
179 ddata->wdd.info = &mpc8xxx_wdt_info,
180 ddata->wdd.ops = &mpc8xxx_wdt_ops,
181
182
183 timeout_sec = (timeout * wdt_type->prescaler) / freq;
184
185 ddata->wdd.timeout = timeout_sec;
186
187 watchdog_set_nowayout(&ddata->wdd, nowayout);
188
189 ret = watchdog_register_device(&ddata->wdd);
190 if (ret) {
191 pr_err("cannot register watchdog device (err=%d)\n", ret);
192 return ret;
193 }
194
195 pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n",
196 reset ? "reset" : "interrupt", timeout, timeout_sec);
197
198
199
200
201
202
203 if (enabled)
204 mod_timer(&ddata->timer, jiffies);
205
206 platform_set_drvdata(ofdev, ddata);
207 return 0;
208}
209
210static int mpc8xxx_wdt_remove(struct platform_device *ofdev)
211{
212 struct mpc8xxx_wdt_ddata *ddata = platform_get_drvdata(ofdev);
213
214 pr_crit("Watchdog removed, expect the %s soon!\n",
215 reset ? "reset" : "machine check exception");
216 del_timer_sync(&ddata->timer);
217 watchdog_unregister_device(&ddata->wdd);
218
219 return 0;
220}
221
222static const struct of_device_id mpc8xxx_wdt_match[] = {
223 {
224 .compatible = "mpc83xx_wdt",
225 .data = &(struct mpc8xxx_wdt_type) {
226 .prescaler = 0x10000,
227 },
228 },
229 {
230 .compatible = "fsl,mpc8610-wdt",
231 .data = &(struct mpc8xxx_wdt_type) {
232 .prescaler = 0x10000,
233 .hw_enabled = true,
234 },
235 },
236 {
237 .compatible = "fsl,mpc823-wdt",
238 .data = &(struct mpc8xxx_wdt_type) {
239 .prescaler = 0x800,
240 .hw_enabled = true,
241 },
242 },
243 {},
244};
245MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
246
247static struct platform_driver mpc8xxx_wdt_driver = {
248 .probe = mpc8xxx_wdt_probe,
249 .remove = mpc8xxx_wdt_remove,
250 .driver = {
251 .name = "mpc8xxx_wdt",
252 .of_match_table = mpc8xxx_wdt_match,
253 },
254};
255
256static int __init mpc8xxx_wdt_init(void)
257{
258 return platform_driver_register(&mpc8xxx_wdt_driver);
259}
260arch_initcall(mpc8xxx_wdt_init);
261
262static void __exit mpc8xxx_wdt_exit(void)
263{
264 platform_driver_unregister(&mpc8xxx_wdt_driver);
265}
266module_exit(mpc8xxx_wdt_exit);
267
268MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
269MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
270 "uProcessors");
271MODULE_LICENSE("GPL");
272
