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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * WDT driver for Lenovo SE30 device
4 */
5
6#define dev_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/io.h>
9#include <linux/dmi.h>
10#include <linux/delay.h>
11#include <linux/iommu.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/platform_device.h>
16#include <linux/watchdog.h>
17
18#define IOREGION_OFFSET 4 /* Use EC port 1 */
19#define IOREGION_LENGTH 4
20
21#define WATCHDOG_TIMEOUT 60
22
23#define MIN_TIMEOUT 1
24#define MAX_TIMEOUT 255
25#define MAX_WAIT 10
26
27static int timeout; /* in seconds */
28module_param(timeout, int, 0);
29MODULE_PARM_DESC(timeout,
30 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
31 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
32
33static bool nowayout = WATCHDOG_NOWAYOUT;
34module_param(nowayout, bool, 0);
35MODULE_PARM_DESC(nowayout,
36 "Watchdog cannot be stopped once started (default="
37 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
38
39#define LNV_SE30_NAME "lenovo-se30-wdt"
40#define LNV_SE30_ID 0x0110
41#define CHIPID_MASK 0xFFF0
42
43#define CHIPID_REG 0x20
44#define SIO_REG 0x2e
45#define LDN_REG 0x07
46#define UNLOCK_KEY 0x87
47#define LOCK_KEY 0xAA
48#define LD_NUM_SHM 0x0F
49#define LD_BASE_ADDR 0xF8
50
51#define WDT_MODULE 0x10
52#define WDT_CFG_INDEX 0x15 /* WD configuration register */
53#define WDT_CNT_INDEX 0x16 /* WD timer count register */
54#define WDT_CFG_RESET 0x2
55
56/* Host Interface WIN2 offset definition */
57#define SHM_WIN_SIZE 0xFF
58#define SHM_WIN_MOD_OFFSET 0x01
59#define SHM_WIN_CMD_OFFSET 0x02
60#define SHM_WIN_SEL_OFFSET 0x03
61#define SHM_WIN_CTL_OFFSET 0x04
62#define VAL_SHM_WIN_CTRL_WR 0x40
63#define VAL_SHM_WIN_CTRL_RD 0x80
64#define SHM_WIN_ID_OFFSET 0x08
65#define SHM_WIN_DAT_OFFSET 0x10
66
67struct nct6692_reg {
68 unsigned char mod;
69 unsigned char cmd;
70 unsigned char sel;
71 unsigned int idx;
72};
73
74/* Watchdog is based on NCT6692 device */
75struct lenovo_se30_wdt {
76 unsigned char __iomem *shm_base_addr;
77 struct nct6692_reg wdt_cfg;
78 struct nct6692_reg wdt_cnt;
79 struct watchdog_device wdt;
80};
81
82static inline void superio_outb(int ioreg, int reg, int val)
83{
84 outb(reg, ioreg);
85 outb(val, ioreg + 1);
86}
87
88static inline int superio_inb(int ioreg, int reg)
89{
90 outb(reg, ioreg);
91 return inb(ioreg + 1);
92}
93
94static inline int superio_enter(int key, int addr, const char *name)
95{
96 if (!request_muxed_region(addr, 2, name)) {
97 pr_err("I/O address 0x%04x already in use\n", addr);
98 return -EBUSY;
99 }
100 outb(key, addr); /* Enter extended function mode */
101 outb(key, addr); /* Again according to manual */
102
103 return 0;
104}
105
106static inline void superio_exit(int key, int addr)
107{
108 outb(key, addr); /* Leave extended function mode */
109 release_region(addr, 2);
110}
111
112static int shm_get_ready(unsigned char __iomem *shm_base_addr,
113 const struct nct6692_reg *reg)
114{
115 unsigned char pre_id, new_id;
116 int loop = 0;
117
118 iowrite8(reg->mod, shm_base_addr + SHM_WIN_MOD_OFFSET);
119 iowrite8(reg->cmd, shm_base_addr + SHM_WIN_CMD_OFFSET);
120 iowrite8(reg->sel, shm_base_addr + SHM_WIN_SEL_OFFSET);
121
122 pre_id = ioread8(shm_base_addr + SHM_WIN_ID_OFFSET);
123 iowrite8(VAL_SHM_WIN_CTRL_RD, shm_base_addr + SHM_WIN_CTL_OFFSET);
124
125 /* Loop checking when interface is ready */
126 while (loop < MAX_WAIT) {
127 new_id = ioread8(shm_base_addr + SHM_WIN_ID_OFFSET);
128 if (new_id != pre_id)
129 return 0;
130 loop++;
131 usleep_range(10, 125);
132 }
133 return -ETIMEDOUT;
134}
135
136static int read_shm_win(unsigned char __iomem *shm_base_addr,
137 const struct nct6692_reg *reg,
138 unsigned char idx_offset,
139 unsigned char *data)
140{
141 int err = shm_get_ready(shm_base_addr, reg);
142
143 if (err)
144 return err;
145 *data = ioread8(shm_base_addr + SHM_WIN_DAT_OFFSET + reg->idx + idx_offset);
146 return 0;
147}
148
149static int write_shm_win(unsigned char __iomem *shm_base_addr,
150 const struct nct6692_reg *reg,
151 unsigned char idx_offset,
152 unsigned char val)
153{
154 int err = shm_get_ready(shm_base_addr, reg);
155
156 if (err)
157 return err;
158 iowrite8(val, shm_base_addr + SHM_WIN_DAT_OFFSET + reg->idx + idx_offset);
159 iowrite8(VAL_SHM_WIN_CTRL_WR, shm_base_addr + SHM_WIN_CTL_OFFSET);
160 err = shm_get_ready(shm_base_addr, reg);
161 return err;
162}
163
164static int lenovo_se30_wdt_enable(struct lenovo_se30_wdt *data, unsigned int timeout)
165{
166 if (timeout) {
167 int err = write_shm_win(data->shm_base_addr, &data->wdt_cfg, 0, WDT_CFG_RESET);
168
169 if (err)
170 return err;
171 }
172 return write_shm_win(data->shm_base_addr, &data->wdt_cnt, 0, timeout);
173}
174
175static int lenovo_se30_wdt_start(struct watchdog_device *wdog)
176{
177 struct lenovo_se30_wdt *data = watchdog_get_drvdata(wdog);
178
179 return lenovo_se30_wdt_enable(data, wdog->timeout);
180}
181
182static int lenovo_se30_wdt_stop(struct watchdog_device *wdog)
183{
184 struct lenovo_se30_wdt *data = watchdog_get_drvdata(wdog);
185
186 return lenovo_se30_wdt_enable(data, 0);
187}
188
189static unsigned int lenovo_se30_wdt_get_timeleft(struct watchdog_device *wdog)
190{
191 struct lenovo_se30_wdt *data = watchdog_get_drvdata(wdog);
192 unsigned char timeleft;
193 int err;
194
195 err = read_shm_win(data->shm_base_addr, &data->wdt_cnt, 0, &timeleft);
196 if (err)
197 return 0;
198 return timeleft;
199}
200
201static int lenovo_se30_wdt_ping(struct watchdog_device *wdt)
202{
203 struct lenovo_se30_wdt *data = watchdog_get_drvdata(wdt);
204 int err = 0;
205
206 /*
207 * Device does not support refreshing WDT_TIMER_REG register when
208 * the watchdog is active. Need to disable, feed and enable again
209 */
210 err = lenovo_se30_wdt_enable(data, 0);
211 if (err)
212 return err;
213
214 err = write_shm_win(data->shm_base_addr, &data->wdt_cnt, 0, wdt->timeout);
215 if (!err)
216 err = lenovo_se30_wdt_enable(data, wdt->timeout);
217
218 return err;
219}
220
221static const struct watchdog_info lenovo_se30_wdt_info = {
222 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
223 WDIOF_MAGICCLOSE,
224 .identity = "Lenovo SE30 watchdog",
225};
226
227static const struct watchdog_ops lenovo_se30_wdt_ops = {
228 .owner = THIS_MODULE,
229 .start = lenovo_se30_wdt_start,
230 .stop = lenovo_se30_wdt_stop,
231 .ping = lenovo_se30_wdt_ping,
232 .get_timeleft = lenovo_se30_wdt_get_timeleft,
233};
234
235static int lenovo_se30_wdt_probe(struct platform_device *pdev)
236{
237 struct device *dev = &pdev->dev;
238 struct lenovo_se30_wdt *priv;
239 unsigned long base_phys;
240 unsigned short val;
241 int err;
242
243 err = superio_enter(UNLOCK_KEY, SIO_REG, LNV_SE30_NAME);
244 if (err)
245 return err;
246
247 val = superio_inb(SIO_REG, CHIPID_REG) << 8;
248 val |= superio_inb(SIO_REG, CHIPID_REG + 1);
249
250 if ((val & CHIPID_MASK) != LNV_SE30_ID) {
251 superio_exit(LOCK_KEY, SIO_REG);
252 return -ENODEV;
253 }
254
255 superio_outb(SIO_REG, LDN_REG, LD_NUM_SHM);
256 base_phys = (superio_inb(SIO_REG, LD_BASE_ADDR) |
257 (superio_inb(SIO_REG, LD_BASE_ADDR + 1) << 8) |
258 (superio_inb(SIO_REG, LD_BASE_ADDR + 2) << 16) |
259 (superio_inb(SIO_REG, LD_BASE_ADDR + 3) << 24)) &
260 0xFFFFFFFF;
261
262 superio_exit(LOCK_KEY, SIO_REG);
263 if (base_phys == 0xFFFFFFFF || base_phys == 0)
264 return -ENODEV;
265
266 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
267 if (!priv)
268 return -ENOMEM;
269
270 if (!devm_request_mem_region(dev, base_phys, SHM_WIN_SIZE, LNV_SE30_NAME))
271 return -EBUSY;
272
273 priv->shm_base_addr = devm_ioremap(dev, base_phys, SHM_WIN_SIZE);
274 if (!priv->shm_base_addr)
275 return -ENOMEM;
276
277 priv->wdt_cfg.mod = WDT_MODULE;
278 priv->wdt_cfg.idx = WDT_CFG_INDEX;
279 priv->wdt_cnt.mod = WDT_MODULE;
280 priv->wdt_cnt.idx = WDT_CNT_INDEX;
281
282 priv->wdt.ops = &lenovo_se30_wdt_ops;
283 priv->wdt.info = &lenovo_se30_wdt_info;
284 priv->wdt.timeout = WATCHDOG_TIMEOUT; /* Set default timeout */
285 priv->wdt.min_timeout = MIN_TIMEOUT;
286 priv->wdt.max_timeout = MAX_TIMEOUT;
287 priv->wdt.parent = dev;
288
289 watchdog_init_timeout(&priv->wdt, timeout, dev);
290 watchdog_set_drvdata(&priv->wdt, priv);
291 watchdog_set_nowayout(&priv->wdt, nowayout);
292 watchdog_stop_on_reboot(&priv->wdt);
293 watchdog_stop_on_unregister(&priv->wdt);
294
295 return devm_watchdog_register_device(dev, &priv->wdt);
296}
297
298static struct platform_device *pdev;
299
300static struct platform_driver lenovo_se30_wdt_driver = {
301 .driver = {
302 .name = LNV_SE30_NAME,
303 },
304 .probe = lenovo_se30_wdt_probe,
305};
306
307static int lenovo_se30_create_platform_device(const struct dmi_system_id *id)
308{
309 int err;
310
311 pdev = platform_device_alloc(LNV_SE30_NAME, -1);
312 if (!pdev)
313 return -ENOMEM;
314
315 err = platform_device_add(pdev);
316 if (err)
317 platform_device_put(pdev);
318
319 return err;
320}
321
322static const struct dmi_system_id lenovo_se30_wdt_dmi_table[] __initconst = {
323 {
324 .ident = "LENOVO-SE30",
325 .matches = {
326 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
327 DMI_MATCH(DMI_PRODUCT_NAME, "11NA"),
328 },
329 .callback = lenovo_se30_create_platform_device,
330 },
331 {
332 .ident = "LENOVO-SE30",
333 .matches = {
334 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
335 DMI_MATCH(DMI_PRODUCT_NAME, "11NB"),
336 },
337 .callback = lenovo_se30_create_platform_device,
338 },
339 {
340 .ident = "LENOVO-SE30",
341 .matches = {
342 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
343 DMI_MATCH(DMI_PRODUCT_NAME, "11NC"),
344 },
345 .callback = lenovo_se30_create_platform_device,
346 },
347 {
348 .ident = "LENOVO-SE30",
349 .matches = {
350 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
351 DMI_MATCH(DMI_PRODUCT_NAME, "11NH"),
352 },
353 .callback = lenovo_se30_create_platform_device,
354 },
355 {
356 .ident = "LENOVO-SE30",
357 .matches = {
358 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
359 DMI_MATCH(DMI_PRODUCT_NAME, "11NJ"),
360 },
361 .callback = lenovo_se30_create_platform_device,
362 },
363 {
364 .ident = "LENOVO-SE30",
365 .matches = {
366 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
367 DMI_MATCH(DMI_PRODUCT_NAME, "11NK"),
368 },
369 .callback = lenovo_se30_create_platform_device,
370 },
371 {}
372};
373MODULE_DEVICE_TABLE(dmi, lenovo_se30_wdt_dmi_table);
374
375static int __init lenovo_se30_wdt_init(void)
376{
377 if (!dmi_check_system(lenovo_se30_wdt_dmi_table))
378 return -ENODEV;
379
380 return platform_driver_register(&lenovo_se30_wdt_driver);
381}
382
383static void __exit lenovo_se30_wdt_exit(void)
384{
385 if (pdev)
386 platform_device_unregister(pdev);
387 platform_driver_unregister(&lenovo_se30_wdt_driver);
388}
389
390module_init(lenovo_se30_wdt_init);
391module_exit(lenovo_se30_wdt_exit);
392
393MODULE_AUTHOR("Mark Pearson <[email protected]>");
394MODULE_AUTHOR("David Ober <[email protected]>");
395MODULE_DESCRIPTION("Lenovo SE30 watchdog driver");
396MODULE_LICENSE("GPL");