]>
Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
efa859f7 JS |
2 | /* |
3 | * Copyright 2016 IBM Corporation | |
4 | * | |
5 | * Joel Stanley <joel@jms.id.au> | |
efa859f7 JS |
6 | */ |
7 | ||
8 | #include <linux/delay.h> | |
9 | #include <linux/io.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/of.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/watchdog.h> | |
15 | ||
16 | struct aspeed_wdt { | |
17 | struct watchdog_device wdd; | |
18 | void __iomem *base; | |
19 | u32 ctrl; | |
20 | }; | |
21 | ||
012c0460 AJ |
22 | struct aspeed_wdt_config { |
23 | u32 ext_pulse_width_mask; | |
24 | }; | |
25 | ||
26 | static const struct aspeed_wdt_config ast2400_config = { | |
27 | .ext_pulse_width_mask = 0xff, | |
28 | }; | |
29 | ||
30 | static const struct aspeed_wdt_config ast2500_config = { | |
31 | .ext_pulse_width_mask = 0xfffff, | |
32 | }; | |
33 | ||
efa859f7 | 34 | static const struct of_device_id aspeed_wdt_of_table[] = { |
012c0460 AJ |
35 | { .compatible = "aspeed,ast2400-wdt", .data = &ast2400_config }, |
36 | { .compatible = "aspeed,ast2500-wdt", .data = &ast2500_config }, | |
b3528b48 | 37 | { .compatible = "aspeed,ast2600-wdt", .data = &ast2500_config }, |
efa859f7 JS |
38 | { }, |
39 | }; | |
40 | MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table); | |
41 | ||
42 | #define WDT_STATUS 0x00 | |
43 | #define WDT_RELOAD_VALUE 0x04 | |
44 | #define WDT_RESTART 0x08 | |
45 | #define WDT_CTRL 0x0C | |
6ffa3402 | 46 | #define WDT_CTRL_BOOT_SECONDARY BIT(7) |
efa859f7 JS |
47 | #define WDT_CTRL_RESET_MODE_SOC (0x00 << 5) |
48 | #define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5) | |
b7f0b8ad | 49 | #define WDT_CTRL_RESET_MODE_ARM_CPU (0x10 << 5) |
efa859f7 JS |
50 | #define WDT_CTRL_1MHZ_CLK BIT(4) |
51 | #define WDT_CTRL_WDT_EXT BIT(3) | |
52 | #define WDT_CTRL_WDT_INTR BIT(2) | |
53 | #define WDT_CTRL_RESET_SYSTEM BIT(1) | |
54 | #define WDT_CTRL_ENABLE BIT(0) | |
49d4d277 EJ |
55 | #define WDT_TIMEOUT_STATUS 0x10 |
56 | #define WDT_TIMEOUT_STATUS_BOOT_SECONDARY BIT(1) | |
3d9e89bd IM |
57 | #define WDT_CLEAR_TIMEOUT_STATUS 0x14 |
58 | #define WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION BIT(0) | |
efa859f7 | 59 | |
012c0460 AJ |
60 | /* |
61 | * WDT_RESET_WIDTH controls the characteristics of the external pulse (if | |
62 | * enabled), specifically: | |
63 | * | |
64 | * * Pulse duration | |
65 | * * Drive mode: push-pull vs open-drain | |
66 | * * Polarity: Active high or active low | |
67 | * | |
68 | * Pulse duration configuration is available on both the AST2400 and AST2500, | |
69 | * though the field changes between SoCs: | |
70 | * | |
71 | * AST2400: Bits 7:0 | |
72 | * AST2500: Bits 19:0 | |
73 | * | |
74 | * This difference is captured in struct aspeed_wdt_config. | |
75 | * | |
76 | * The AST2500 exposes the drive mode and polarity options, but not in a | |
77 | * regular fashion. For read purposes, bit 31 represents active high or low, | |
78 | * and bit 30 represents push-pull or open-drain. With respect to write, magic | |
79 | * values need to be written to the top byte to change the state of the drive | |
80 | * mode and polarity bits. Any other value written to the top byte has no | |
81 | * effect on the state of the drive mode or polarity bits. However, the pulse | |
82 | * width value must be preserved (as desired) if written. | |
83 | */ | |
84 | #define WDT_RESET_WIDTH 0x18 | |
85 | #define WDT_RESET_WIDTH_ACTIVE_HIGH BIT(31) | |
86 | #define WDT_ACTIVE_HIGH_MAGIC (0xA5 << 24) | |
87 | #define WDT_ACTIVE_LOW_MAGIC (0x5A << 24) | |
88 | #define WDT_RESET_WIDTH_PUSH_PULL BIT(30) | |
89 | #define WDT_PUSH_PULL_MAGIC (0xA8 << 24) | |
90 | #define WDT_OPEN_DRAIN_MAGIC (0x8A << 24) | |
91 | ||
efa859f7 JS |
92 | #define WDT_RESTART_MAGIC 0x4755 |
93 | ||
94 | /* 32 bits at 1MHz, in milliseconds */ | |
95 | #define WDT_MAX_TIMEOUT_MS 4294967 | |
96 | #define WDT_DEFAULT_TIMEOUT 30 | |
97 | #define WDT_RATE_1MHZ 1000000 | |
98 | ||
99 | static struct aspeed_wdt *to_aspeed_wdt(struct watchdog_device *wdd) | |
100 | { | |
101 | return container_of(wdd, struct aspeed_wdt, wdd); | |
102 | } | |
103 | ||
104 | static void aspeed_wdt_enable(struct aspeed_wdt *wdt, int count) | |
105 | { | |
106 | wdt->ctrl |= WDT_CTRL_ENABLE; | |
107 | ||
108 | writel(0, wdt->base + WDT_CTRL); | |
109 | writel(count, wdt->base + WDT_RELOAD_VALUE); | |
110 | writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART); | |
111 | writel(wdt->ctrl, wdt->base + WDT_CTRL); | |
112 | } | |
113 | ||
114 | static int aspeed_wdt_start(struct watchdog_device *wdd) | |
115 | { | |
116 | struct aspeed_wdt *wdt = to_aspeed_wdt(wdd); | |
117 | ||
118 | aspeed_wdt_enable(wdt, wdd->timeout * WDT_RATE_1MHZ); | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | static int aspeed_wdt_stop(struct watchdog_device *wdd) | |
124 | { | |
125 | struct aspeed_wdt *wdt = to_aspeed_wdt(wdd); | |
126 | ||
127 | wdt->ctrl &= ~WDT_CTRL_ENABLE; | |
128 | writel(wdt->ctrl, wdt->base + WDT_CTRL); | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | static int aspeed_wdt_ping(struct watchdog_device *wdd) | |
134 | { | |
135 | struct aspeed_wdt *wdt = to_aspeed_wdt(wdd); | |
136 | ||
137 | writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int aspeed_wdt_set_timeout(struct watchdog_device *wdd, | |
143 | unsigned int timeout) | |
144 | { | |
145 | struct aspeed_wdt *wdt = to_aspeed_wdt(wdd); | |
146 | u32 actual; | |
147 | ||
148 | wdd->timeout = timeout; | |
149 | ||
150 | actual = min(timeout, wdd->max_hw_heartbeat_ms * 1000); | |
151 | ||
152 | writel(actual * WDT_RATE_1MHZ, wdt->base + WDT_RELOAD_VALUE); | |
153 | writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static int aspeed_wdt_restart(struct watchdog_device *wdd, | |
159 | unsigned long action, void *data) | |
160 | { | |
161 | struct aspeed_wdt *wdt = to_aspeed_wdt(wdd); | |
162 | ||
6ffa3402 | 163 | wdt->ctrl &= ~WDT_CTRL_BOOT_SECONDARY; |
efa859f7 JS |
164 | aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000); |
165 | ||
166 | mdelay(1000); | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
3d9e89bd IM |
171 | /* access_cs0 shows if cs0 is accessible, hence the reverted bit */ |
172 | static ssize_t access_cs0_show(struct device *dev, | |
173 | struct device_attribute *attr, char *buf) | |
174 | { | |
175 | struct aspeed_wdt *wdt = dev_get_drvdata(dev); | |
176 | u32 status = readl(wdt->base + WDT_TIMEOUT_STATUS); | |
177 | ||
178 | return sprintf(buf, "%u\n", | |
179 | !(status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY)); | |
180 | } | |
181 | ||
182 | static ssize_t access_cs0_store(struct device *dev, | |
183 | struct device_attribute *attr, const char *buf, | |
184 | size_t size) | |
185 | { | |
186 | struct aspeed_wdt *wdt = dev_get_drvdata(dev); | |
187 | unsigned long val; | |
188 | ||
189 | if (kstrtoul(buf, 10, &val)) | |
190 | return -EINVAL; | |
191 | ||
192 | if (val) | |
193 | writel(WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION, | |
194 | wdt->base + WDT_CLEAR_TIMEOUT_STATUS); | |
195 | ||
196 | return size; | |
197 | } | |
198 | ||
199 | /* | |
200 | * This attribute exists only if the system has booted from the alternate | |
201 | * flash with 'alt-boot' option. | |
202 | * | |
203 | * At alternate flash the 'access_cs0' sysfs node provides: | |
204 | * ast2400: a way to get access to the primary SPI flash chip at CS0 | |
205 | * after booting from the alternate chip at CS1. | |
206 | * ast2500: a way to restore the normal address mapping from | |
207 | * (CS0->CS1, CS1->CS0) to (CS0->CS0, CS1->CS1). | |
208 | * | |
209 | * Clearing the boot code selection and timeout counter also resets to the | |
210 | * initial state the chip select line mapping. When the SoC is in normal | |
211 | * mapping state (i.e. booted from CS0), clearing those bits does nothing for | |
212 | * both versions of the SoC. For alternate boot mode (booted from CS1 due to | |
213 | * wdt2 expiration) the behavior differs as described above. | |
214 | * | |
215 | * This option can be used with wdt2 (watchdog1) only. | |
216 | */ | |
217 | static DEVICE_ATTR_RW(access_cs0); | |
218 | ||
219 | static struct attribute *bswitch_attrs[] = { | |
220 | &dev_attr_access_cs0.attr, | |
221 | NULL | |
222 | }; | |
223 | ATTRIBUTE_GROUPS(bswitch); | |
224 | ||
efa859f7 JS |
225 | static const struct watchdog_ops aspeed_wdt_ops = { |
226 | .start = aspeed_wdt_start, | |
227 | .stop = aspeed_wdt_stop, | |
228 | .ping = aspeed_wdt_ping, | |
229 | .set_timeout = aspeed_wdt_set_timeout, | |
230 | .restart = aspeed_wdt_restart, | |
231 | .owner = THIS_MODULE, | |
232 | }; | |
233 | ||
234 | static const struct watchdog_info aspeed_wdt_info = { | |
235 | .options = WDIOF_KEEPALIVEPING | |
236 | | WDIOF_MAGICCLOSE | |
237 | | WDIOF_SETTIMEOUT, | |
238 | .identity = KBUILD_MODNAME, | |
239 | }; | |
240 | ||
efa859f7 JS |
241 | static int aspeed_wdt_probe(struct platform_device *pdev) |
242 | { | |
eda21ee9 | 243 | struct device *dev = &pdev->dev; |
012c0460 AJ |
244 | const struct aspeed_wdt_config *config; |
245 | const struct of_device_id *ofdid; | |
efa859f7 | 246 | struct aspeed_wdt *wdt; |
b7f0b8ad CB |
247 | struct device_node *np; |
248 | const char *reset_type; | |
012c0460 | 249 | u32 duration; |
49d4d277 | 250 | u32 status; |
efa859f7 JS |
251 | int ret; |
252 | ||
eda21ee9 | 253 | wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); |
efa859f7 JS |
254 | if (!wdt) |
255 | return -ENOMEM; | |
256 | ||
0f0a6a28 | 257 | wdt->base = devm_platform_ioremap_resource(pdev, 0); |
efa859f7 JS |
258 | if (IS_ERR(wdt->base)) |
259 | return PTR_ERR(wdt->base); | |
260 | ||
efa859f7 JS |
261 | wdt->wdd.info = &aspeed_wdt_info; |
262 | wdt->wdd.ops = &aspeed_wdt_ops; | |
263 | wdt->wdd.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT_MS; | |
eda21ee9 | 264 | wdt->wdd.parent = dev; |
efa859f7 JS |
265 | |
266 | wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT; | |
eda21ee9 | 267 | watchdog_init_timeout(&wdt->wdd, 0, dev); |
efa859f7 | 268 | |
eda21ee9 | 269 | np = dev->of_node; |
012c0460 AJ |
270 | |
271 | ofdid = of_match_node(aspeed_wdt_of_table, np); | |
272 | if (!ofdid) | |
273 | return -EINVAL; | |
274 | config = ofdid->data; | |
275 | ||
c0457125 JS |
276 | /* |
277 | * On clock rates: | |
278 | * - ast2400 wdt can run at PCLK, or 1MHz | |
279 | * - ast2500 only runs at 1MHz, hard coding bit 4 to 1 | |
280 | * - ast2600 always runs at 1MHz | |
281 | * | |
282 | * Set the ast2400 to run at 1MHz as it simplifies the driver. | |
283 | */ | |
284 | if (of_device_is_compatible(np, "aspeed,ast2400-wdt")) | |
285 | wdt->ctrl = WDT_CTRL_1MHZ_CLK; | |
b7f0b8ad | 286 | |
efa859f7 JS |
287 | /* |
288 | * Control reset on a per-device basis to ensure the | |
b7f0b8ad | 289 | * host is not affected by a BMC reboot |
efa859f7 | 290 | */ |
b7f0b8ad CB |
291 | ret = of_property_read_string(np, "aspeed,reset-type", &reset_type); |
292 | if (ret) { | |
293 | wdt->ctrl |= WDT_CTRL_RESET_MODE_SOC | WDT_CTRL_RESET_SYSTEM; | |
294 | } else { | |
295 | if (!strcmp(reset_type, "cpu")) | |
d2fc8db6 MM |
296 | wdt->ctrl |= WDT_CTRL_RESET_MODE_ARM_CPU | |
297 | WDT_CTRL_RESET_SYSTEM; | |
b7f0b8ad | 298 | else if (!strcmp(reset_type, "soc")) |
d2fc8db6 MM |
299 | wdt->ctrl |= WDT_CTRL_RESET_MODE_SOC | |
300 | WDT_CTRL_RESET_SYSTEM; | |
b7f0b8ad | 301 | else if (!strcmp(reset_type, "system")) |
d2fc8db6 MM |
302 | wdt->ctrl |= WDT_CTRL_RESET_MODE_FULL_CHIP | |
303 | WDT_CTRL_RESET_SYSTEM; | |
b7f0b8ad CB |
304 | else if (strcmp(reset_type, "none")) |
305 | return -EINVAL; | |
306 | } | |
307 | if (of_property_read_bool(np, "aspeed,external-signal")) | |
308 | wdt->ctrl |= WDT_CTRL_WDT_EXT; | |
6ffa3402 MM |
309 | if (of_property_read_bool(np, "aspeed,alt-boot")) |
310 | wdt->ctrl |= WDT_CTRL_BOOT_SECONDARY; | |
b7f0b8ad | 311 | |
efa859f7 | 312 | if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) { |
9f3e13c7 AJ |
313 | /* |
314 | * The watchdog is running, but invoke aspeed_wdt_start() to | |
315 | * write wdt->ctrl to WDT_CTRL to ensure the watchdog's | |
316 | * configuration conforms to the driver's expectations. | |
317 | * Primarily, ensure we're using the 1MHz clock source. | |
318 | */ | |
efa859f7 JS |
319 | aspeed_wdt_start(&wdt->wdd); |
320 | set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); | |
321 | } | |
322 | ||
b3528b48 RC |
323 | if ((of_device_is_compatible(np, "aspeed,ast2500-wdt")) || |
324 | (of_device_is_compatible(np, "aspeed,ast2600-wdt"))) { | |
012c0460 AJ |
325 | u32 reg = readl(wdt->base + WDT_RESET_WIDTH); |
326 | ||
327 | reg &= config->ext_pulse_width_mask; | |
328 | if (of_property_read_bool(np, "aspeed,ext-push-pull")) | |
329 | reg |= WDT_PUSH_PULL_MAGIC; | |
330 | else | |
331 | reg |= WDT_OPEN_DRAIN_MAGIC; | |
332 | ||
333 | writel(reg, wdt->base + WDT_RESET_WIDTH); | |
334 | ||
335 | reg &= config->ext_pulse_width_mask; | |
336 | if (of_property_read_bool(np, "aspeed,ext-active-high")) | |
337 | reg |= WDT_ACTIVE_HIGH_MAGIC; | |
338 | else | |
339 | reg |= WDT_ACTIVE_LOW_MAGIC; | |
340 | ||
341 | writel(reg, wdt->base + WDT_RESET_WIDTH); | |
342 | } | |
343 | ||
344 | if (!of_property_read_u32(np, "aspeed,ext-pulse-duration", &duration)) { | |
345 | u32 max_duration = config->ext_pulse_width_mask + 1; | |
346 | ||
347 | if (duration == 0 || duration > max_duration) { | |
eda21ee9 GR |
348 | dev_err(dev, "Invalid pulse duration: %uus\n", |
349 | duration); | |
012c0460 | 350 | duration = max(1U, min(max_duration, duration)); |
eda21ee9 GR |
351 | dev_info(dev, "Pulse duration set to %uus\n", |
352 | duration); | |
012c0460 AJ |
353 | } |
354 | ||
355 | /* | |
356 | * The watchdog is always configured with a 1MHz source, so | |
357 | * there is no need to scale the microsecond value. However we | |
358 | * need to offset it - from the datasheet: | |
359 | * | |
360 | * "This register decides the asserting duration of wdt_ext and | |
361 | * wdt_rstarm signal. The default value is 0xFF. It means the | |
362 | * default asserting duration of wdt_ext and wdt_rstarm is | |
363 | * 256us." | |
364 | * | |
365 | * This implies a value of 0 gives a 1us pulse. | |
366 | */ | |
367 | writel(duration - 1, wdt->base + WDT_RESET_WIDTH); | |
368 | } | |
369 | ||
49d4d277 | 370 | status = readl(wdt->base + WDT_TIMEOUT_STATUS); |
3d9e89bd | 371 | if (status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY) { |
49d4d277 EJ |
372 | wdt->wdd.bootstatus = WDIOF_CARDRESET; |
373 | ||
3d9e89bd IM |
374 | if (of_device_is_compatible(np, "aspeed,ast2400-wdt") || |
375 | of_device_is_compatible(np, "aspeed,ast2500-wdt")) | |
376 | wdt->wdd.groups = bswitch_groups; | |
377 | } | |
378 | ||
379 | dev_set_drvdata(dev, wdt); | |
380 | ||
4ab05433 | 381 | return devm_watchdog_register_device(dev, &wdt->wdd); |
efa859f7 JS |
382 | } |
383 | ||
384 | static struct platform_driver aspeed_watchdog_driver = { | |
385 | .probe = aspeed_wdt_probe, | |
efa859f7 JS |
386 | .driver = { |
387 | .name = KBUILD_MODNAME, | |
388 | .of_match_table = of_match_ptr(aspeed_wdt_of_table), | |
389 | }, | |
390 | }; | |
d4238aa4 AJ |
391 | |
392 | static int __init aspeed_wdt_init(void) | |
393 | { | |
394 | return platform_driver_register(&aspeed_watchdog_driver); | |
395 | } | |
396 | arch_initcall(aspeed_wdt_init); | |
397 | ||
398 | static void __exit aspeed_wdt_exit(void) | |
399 | { | |
400 | platform_driver_unregister(&aspeed_watchdog_driver); | |
401 | } | |
402 | module_exit(aspeed_wdt_exit); | |
efa859f7 JS |
403 | |
404 | MODULE_DESCRIPTION("Aspeed Watchdog Driver"); | |
405 | MODULE_LICENSE("GPL"); |