xref: /linux/drivers/watchdog/lenovo_se10_wdt.c (revision 3394e894880a60338a2981dd688fd25e88d79667) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * WDT driver for Lenovo SE10.
4  */
5 
6 #include <linux/delay.h>
7 #include <linux/dmi.h>
8 #include <linux/io.h>
9 #include <linux/module.h>
10 #include <linux/moduleparam.h>
11 #include <linux/platform_device.h>
12 #include <linux/string.h>
13 #include <linux/types.h>
14 #include <linux/watchdog.h>
15 
16 #define STATUS_PORT	0x6C
17 #define CMD_PORT	0x6C
18 #define DATA_PORT	0x68
19 #define OUTBUF_FULL	0x01
20 #define INBUF_EMPTY	0x02
21 #define CFG_LDN		0x07
22 #define CFG_BRAM_LDN	0x10 /* for BRAM Base */
23 #define CFG_PORT	0x2E
24 #define CFG_SIZE           2
25 #define CMD_SIZE           4
26 #define BRAM_SIZE          2
27 
28 #define UNLOCK_KEY	0x87
29 #define LOCK_KEY	0xAA
30 
31 #define CUS_WDT_SWI	0x1A
32 #define CUS_WDT_CFG	0x1B
33 #define CUS_WDT_FEED	0xB0
34 #define CUS_WDT_CNT	0xB1
35 
36 #define DRVNAME	"lenovo-se10-wdt"
37 
38 /*The timeout range is 1-255 seconds*/
39 #define MIN_TIMEOUT 1
40 #define MAX_TIMEOUT 255
41 #define MAX_WAIT    10
42 
43 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
44 static unsigned short bram_base;
45 static struct platform_device *se10_pdev;
46 
47 static int timeout; /* in seconds */
48 module_param(timeout, int, 0);
49 MODULE_PARM_DESC(timeout,
50 		 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
51 		 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
52 
53 static bool nowayout = WATCHDOG_NOWAYOUT;
54 module_param(nowayout, bool, 0);
55 MODULE_PARM_DESC(nowayout,
56 		 "Watchdog cannot be stopped once started (default="
57 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
58 
59 struct se10_wdt {
60 	struct watchdog_device wdd;
61 };
62 
63 static int set_bram(unsigned char offset, unsigned char val)
64 {
65 	if (!request_muxed_region(bram_base, BRAM_SIZE, DRVNAME))
66 		return -EBUSY;
67 	outb(offset, bram_base);
68 	outb(val, bram_base + 1);
69 	release_region(bram_base, BRAM_SIZE);
70 	return 0;
71 }
72 
73 static void wait_for_buffer(int condition)
74 {
75 	int loop = 0;
76 
77 	while (1) {
78 		if (inb(STATUS_PORT) & condition || loop > MAX_WAIT)
79 			break;
80 		loop++;
81 		usleep_range(10, 125);
82 	}
83 }
84 
85 static void send_cmd(unsigned char cmd)
86 {
87 	wait_for_buffer(INBUF_EMPTY);
88 	outb(cmd, CMD_PORT);
89 	wait_for_buffer(INBUF_EMPTY);
90 }
91 
92 static void lpc_write(unsigned char index, unsigned char data)
93 {
94 	outb(index, CFG_PORT);
95 	outb(data, CFG_PORT + 1);
96 }
97 
98 static unsigned char lpc_read(unsigned char index)
99 {
100 	outb(index, CFG_PORT);
101 	return inb(CFG_PORT + 1);
102 }
103 
104 static int wdt_start(struct watchdog_device *wdog)
105 {
106 	return set_bram(CUS_WDT_SWI, 0x80);
107 }
108 
109 static int wdt_set_timeout(struct watchdog_device *wdog, unsigned int timeout)
110 {
111 	wdog->timeout = timeout;
112 	return set_bram(CUS_WDT_CFG, wdog->timeout);
113 }
114 
115 static int wdt_stop(struct watchdog_device *wdog)
116 {
117 	return set_bram(CUS_WDT_SWI, 0);
118 }
119 
120 static unsigned int wdt_get_time(struct watchdog_device *wdog)
121 {
122 	unsigned char time;
123 
124 	if (!request_muxed_region(CMD_PORT, CMD_SIZE, DRVNAME))
125 		return -EBUSY;
126 	send_cmd(CUS_WDT_CNT);
127 	wait_for_buffer(OUTBUF_FULL);
128 	time = inb(DATA_PORT);
129 	release_region(CMD_PORT, CMD_SIZE);
130 	return time;
131 }
132 
133 static int wdt_ping(struct watchdog_device *wdog)
134 {
135 	if (!request_muxed_region(CMD_PORT, CMD_SIZE, DRVNAME))
136 		return -EBUSY;
137 	send_cmd(CUS_WDT_FEED);
138 	release_region(CMD_PORT, CMD_SIZE);
139 	return 0;
140 }
141 
142 static const struct watchdog_info wdt_info = {
143 	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
144 	.identity = "Lenovo SE10 Watchdog",
145 };
146 
147 static const struct watchdog_ops se10_wdt_ops = {
148 	.owner = THIS_MODULE,
149 	.start = wdt_start,
150 	.stop = wdt_stop,
151 	.ping = wdt_ping,
152 	.set_timeout = wdt_set_timeout,
153 	.get_timeleft = wdt_get_time,
154 };
155 
156 static unsigned int get_chipID(void)
157 {
158 	unsigned char msb, lsb;
159 
160 	outb(UNLOCK_KEY, CFG_PORT);
161 	outb(0x01, CFG_PORT);
162 	outb(0x55, CFG_PORT);
163 	outb(0x55, CFG_PORT);
164 	msb = lpc_read(0x20);
165 	lsb = lpc_read(0x21);
166 	outb(LOCK_KEY, CFG_PORT);
167 	return (msb * 256 + lsb);
168 }
169 
170 static int se10_wdt_probe(struct platform_device *pdev)
171 {
172 	struct device *dev = &pdev->dev;
173 	struct se10_wdt *priv;
174 	unsigned int chip_id;
175 	int ret;
176 
177 	if (!request_muxed_region(CFG_PORT, CFG_SIZE, DRVNAME))
178 		return -EBUSY;
179 
180 	chip_id = get_chipID();
181 	if (chip_id != 0x5632 && chip_id != 0x5652) {
182 		release_region(CFG_PORT, CFG_SIZE);
183 		return -ENODEV;
184 	}
185 
186 	lpc_write(CFG_LDN, CFG_BRAM_LDN);
187 	bram_base = (lpc_read(0x60) << 8) | lpc_read(0x61);
188 	release_region(CFG_PORT, CFG_SIZE);
189 
190 	dev_info(dev, "Found Lenovo SE10 0x%x\n", chip_id);
191 
192 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
193 	if (!priv)
194 		return -ENOMEM;
195 
196 	watchdog_set_drvdata(&priv->wdd, priv);
197 
198 	priv->wdd.parent = dev;
199 	priv->wdd.info = &wdt_info;
200 	priv->wdd.ops = &se10_wdt_ops;
201 	priv->wdd.timeout = WATCHDOG_TIMEOUT; /* Set default timeout */
202 	priv->wdd.min_timeout = MIN_TIMEOUT;
203 	priv->wdd.max_timeout = MAX_TIMEOUT;
204 
205 	set_bram(CUS_WDT_CFG, WATCHDOG_TIMEOUT); /* Set time to default */
206 
207 	watchdog_init_timeout(&priv->wdd, timeout, dev);
208 	watchdog_set_nowayout(&priv->wdd, nowayout);
209 	watchdog_stop_on_reboot(&priv->wdd);
210 	watchdog_stop_on_unregister(&priv->wdd);
211 
212 	ret = devm_watchdog_register_device(dev, &priv->wdd);
213 
214 	dev_dbg(&pdev->dev, "initialized. timeout=%d sec (nowayout=%d)\n",
215 		priv->wdd.timeout, nowayout);
216 
217 	return ret;
218 }
219 
220 static struct platform_driver se10_wdt_driver = {
221 	.driver = {
222 		.name = DRVNAME,
223 	},
224 	.probe  = se10_wdt_probe,
225 };
226 
227 static int se10_create_platform_device(void)
228 {
229 	int err;
230 
231 	se10_pdev = platform_device_alloc("lenovo-se10-wdt", -1);
232 	if (!se10_pdev)
233 		return -ENOMEM;
234 
235 	err = platform_device_add(se10_pdev);
236 	if (err) {
237 		platform_device_put(se10_pdev);
238 		se10_pdev = NULL;
239 	}
240 	return err;
241 }
242 
243 static const struct dmi_system_id se10_dmi_table[] __initconst = {
244 	{
245 		.ident = "LENOVO-SE10",
246 		.matches = {
247 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
248 			DMI_MATCH(DMI_PRODUCT_NAME, "12NH"),
249 		},
250 	},
251 	{
252 		.ident = "LENOVO-SE10",
253 		.matches = {
254 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
255 			DMI_MATCH(DMI_PRODUCT_NAME, "12NJ"),
256 		},
257 	},
258 	{
259 		.ident = "LENOVO-SE10",
260 		.matches = {
261 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
262 			DMI_MATCH(DMI_PRODUCT_NAME, "12NK"),
263 		},
264 	},
265 	{
266 		.ident = "LENOVO-SE10",
267 		.matches = {
268 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
269 			DMI_MATCH(DMI_PRODUCT_NAME, "12NL"),
270 		},
271 	},
272 	{
273 		.ident = "LENOVO-SE10",
274 		.matches = {
275 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
276 			DMI_MATCH(DMI_PRODUCT_NAME, "12NM"),
277 		},
278 	},
279 	{
280 		.ident = "LENOVO-SE10-G2",
281 		.matches = {
282 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
283 			DMI_MATCH(DMI_PRODUCT_NAME, "13LJ"),
284 		},
285 	},
286 	{
287 		.ident = "LENOVO-SE10-G2",
288 		.matches = {
289 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
290 			DMI_MATCH(DMI_PRODUCT_NAME, "13LK"),
291 		},
292 	},
293 	{
294 		.ident = "LENOVO-SE10-G2",
295 		.matches = {
296 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
297 			DMI_MATCH(DMI_PRODUCT_NAME, "13S1"),
298 		},
299 	},
300 	{
301 		.ident = "LENOVO-SE10-G2",
302 		.matches = {
303 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
304 			DMI_MATCH(DMI_PRODUCT_NAME, "13S2"),
305 		},
306 	},
307 	{
308 		.ident = "LENOVO-SE10-G2",
309 		.matches = {
310 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
311 			DMI_MATCH(DMI_PRODUCT_NAME, "13S3"),
312 		},
313 	},
314 	{
315 		.ident = "LENOVO-SE10-G2",
316 		.matches = {
317 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
318 			DMI_MATCH(DMI_PRODUCT_NAME, "13S4"),
319 		},
320 	},
321 	{
322 		.ident = "LENOVO-SE10-G2",
323 		.matches = {
324 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
325 			DMI_MATCH(DMI_PRODUCT_NAME, "13S5"),
326 		},
327 	},
328 	{
329 		.ident = "LENOVO-SE10-G2",
330 		.matches = {
331 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
332 			DMI_MATCH(DMI_PRODUCT_NAME, "13S6"),
333 		},
334 	},
335 	{}
336 };
337 MODULE_DEVICE_TABLE(dmi, se10_dmi_table);
338 
339 static int __init se10_wdt_init(void)
340 {
341 	int err;
342 
343 	if (!dmi_check_system(se10_dmi_table))
344 		return -ENODEV;
345 
346 	err = platform_driver_register(&se10_wdt_driver);
347 	if (err)
348 		return err;
349 
350 	err = se10_create_platform_device();
351 	if (err)
352 		platform_driver_unregister(&se10_wdt_driver);
353 
354 	return err;
355 }
356 
357 static void __exit se10_wdt_exit(void)
358 {
359 	if (se10_pdev)
360 		platform_device_unregister(se10_pdev);
361 	platform_driver_unregister(&se10_wdt_driver);
362 }
363 
364 module_init(se10_wdt_init);
365 module_exit(se10_wdt_exit);
366 
367 MODULE_LICENSE("GPL");
368 MODULE_AUTHOR("David Ober<dober@lenovo.com>");
369 MODULE_AUTHOR("Mark Pearson <mpearson-lenovo@squebb.ca>");
370 MODULE_DESCRIPTION("WDT driver for Lenovo SE10");
371