Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
3 */
4#include <linux/bits.h>
5#include <linux/clk.h>
6#include <linux/delay.h>
7#include <linux/interrupt.h>
8#include <linux/io.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/watchdog.h>
14
15enum wdt_reg {
16 WDT_RST,
17 WDT_EN,
18 WDT_STS,
19 WDT_BARK_TIME,
20 WDT_BITE_TIME,
21};
22
23#define QCOM_WDT_ENABLE BIT(0)
24
25static const u32 reg_offset_data_apcs_tmr[] = {
26 [WDT_RST] = 0x38,
27 [WDT_EN] = 0x40,
28 [WDT_STS] = 0x44,
29 [WDT_BARK_TIME] = 0x4C,
30 [WDT_BITE_TIME] = 0x5C,
31};
32
33static const u32 reg_offset_data_kpss[] = {
34 [WDT_RST] = 0x4,
35 [WDT_EN] = 0x8,
36 [WDT_STS] = 0xC,
37 [WDT_BARK_TIME] = 0x10,
38 [WDT_BITE_TIME] = 0x14,
39};
40
41struct qcom_wdt_match_data {
42 const u32 *offset;
43 bool pretimeout;
44};
45
46struct qcom_wdt {
47 struct watchdog_device wdd;
48 unsigned long rate;
49 void __iomem *base;
50 const u32 *layout;
51};
52
53static void __iomem *wdt_addr(struct qcom_wdt *wdt, enum wdt_reg reg)
54{
55 return wdt->base + wdt->layout[reg];
56}
57
58static inline
59struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd)
60{
61 return container_of(wdd, struct qcom_wdt, wdd);
62}
63
64static irqreturn_t qcom_wdt_isr(int irq, void *arg)
65{
66 struct watchdog_device *wdd = arg;
67
68 watchdog_notify_pretimeout(wdd);
69
70 return IRQ_HANDLED;
71}
72
73static int qcom_wdt_start(struct watchdog_device *wdd)
74{
75 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
76 unsigned int bark = wdd->timeout - wdd->pretimeout;
77
78 writel(0, wdt_addr(wdt, WDT_EN));
79 writel(1, wdt_addr(wdt, WDT_RST));
80 writel(bark * wdt->rate, wdt_addr(wdt, WDT_BARK_TIME));
81 writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BITE_TIME));
82 writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN));
83 return 0;
84}
85
86static int qcom_wdt_stop(struct watchdog_device *wdd)
87{
88 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
89
90 writel(0, wdt_addr(wdt, WDT_EN));
91 return 0;
92}
93
94static int qcom_wdt_ping(struct watchdog_device *wdd)
95{
96 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
97
98 writel(1, wdt_addr(wdt, WDT_RST));
99 return 0;
100}
101
102static int qcom_wdt_set_timeout(struct watchdog_device *wdd,
103 unsigned int timeout)
104{
105 wdd->timeout = timeout;
106 return qcom_wdt_start(wdd);
107}
108
109static int qcom_wdt_set_pretimeout(struct watchdog_device *wdd,
110 unsigned int timeout)
111{
112 wdd->pretimeout = timeout;
113 return qcom_wdt_start(wdd);
114}
115
116static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action,
117 void *data)
118{
119 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
120 u32 timeout;
121
122 /*
123 * Trigger watchdog bite:
124 * Setup BITE_TIME to be 128ms, and enable WDT.
125 */
126 timeout = 128 * wdt->rate / 1000;
127
128 writel(0, wdt_addr(wdt, WDT_EN));
129 writel(1, wdt_addr(wdt, WDT_RST));
130 writel(timeout, wdt_addr(wdt, WDT_BARK_TIME));
131 writel(timeout, wdt_addr(wdt, WDT_BITE_TIME));
132 writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN));
133
134 /*
135 * Actually make sure the above sequence hits hardware before sleeping.
136 */
137 wmb();
138
139 mdelay(150);
140 return 0;
141}
142
143static int qcom_wdt_is_running(struct watchdog_device *wdd)
144{
145 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
146
147 return (readl(wdt_addr(wdt, WDT_EN)) & QCOM_WDT_ENABLE);
148}
149
150static const struct watchdog_ops qcom_wdt_ops = {
151 .start = qcom_wdt_start,
152 .stop = qcom_wdt_stop,
153 .ping = qcom_wdt_ping,
154 .set_timeout = qcom_wdt_set_timeout,
155 .set_pretimeout = qcom_wdt_set_pretimeout,
156 .restart = qcom_wdt_restart,
157 .owner = THIS_MODULE,
158};
159
160static const struct watchdog_info qcom_wdt_info = {
161 .options = WDIOF_KEEPALIVEPING
162 | WDIOF_MAGICCLOSE
163 | WDIOF_SETTIMEOUT
164 | WDIOF_CARDRESET,
165 .identity = KBUILD_MODNAME,
166};
167
168static const struct watchdog_info qcom_wdt_pt_info = {
169 .options = WDIOF_KEEPALIVEPING
170 | WDIOF_MAGICCLOSE
171 | WDIOF_SETTIMEOUT
172 | WDIOF_PRETIMEOUT
173 | WDIOF_CARDRESET,
174 .identity = KBUILD_MODNAME,
175};
176
177static const struct qcom_wdt_match_data match_data_apcs_tmr = {
178 .offset = reg_offset_data_apcs_tmr,
179 .pretimeout = false,
180};
181
182static const struct qcom_wdt_match_data match_data_kpss = {
183 .offset = reg_offset_data_kpss,
184 .pretimeout = true,
185};
186
187static int qcom_wdt_probe(struct platform_device *pdev)
188{
189 struct device *dev = &pdev->dev;
190 struct qcom_wdt *wdt;
191 struct resource *res;
192 struct device_node *np = dev->of_node;
193 const struct qcom_wdt_match_data *data;
194 u32 percpu_offset;
195 int irq, ret;
196 struct clk *clk;
197
198 data = of_device_get_match_data(dev);
199 if (!data) {
200 dev_err(dev, "Unsupported QCOM WDT module\n");
201 return -ENODEV;
202 }
203
204 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
205 if (!wdt)
206 return -ENOMEM;
207
208 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
209 if (!res)
210 return -ENOMEM;
211
212 /* We use CPU0's DGT for the watchdog */
213 if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
214 percpu_offset = 0;
215
216 res->start += percpu_offset;
217 res->end += percpu_offset;
218
219 wdt->base = devm_ioremap_resource(dev, res);
220 if (IS_ERR(wdt->base))
221 return PTR_ERR(wdt->base);
222
223 clk = devm_clk_get_enabled(dev, NULL);
224 if (IS_ERR(clk)) {
225 dev_err(dev, "failed to get input clock\n");
226 return PTR_ERR(clk);
227 }
228
229 /*
230 * We use the clock rate to calculate the max timeout, so ensure it's
231 * not zero to avoid a divide-by-zero exception.
232 *
233 * WATCHDOG_CORE assumes units of seconds, if the WDT is clocked such
234 * that it would bite before a second elapses it's usefulness is
235 * limited. Bail if this is the case.
236 */
237 wdt->rate = clk_get_rate(clk);
238 if (wdt->rate == 0 ||
239 wdt->rate > 0x10000000U) {
240 dev_err(dev, "invalid clock rate\n");
241 return -EINVAL;
242 }
243
244 /* check if there is pretimeout support */
245 irq = platform_get_irq_optional(pdev, 0);
246 if (data->pretimeout && irq > 0) {
247 ret = devm_request_irq(dev, irq, qcom_wdt_isr, 0,
248 "wdt_bark", &wdt->wdd);
249 if (ret)
250 return ret;
251
252 wdt->wdd.info = &qcom_wdt_pt_info;
253 wdt->wdd.pretimeout = 1;
254 } else {
255 if (irq == -EPROBE_DEFER)
256 return -EPROBE_DEFER;
257
258 wdt->wdd.info = &qcom_wdt_info;
259 }
260
261 wdt->wdd.ops = &qcom_wdt_ops;
262 wdt->wdd.min_timeout = 1;
263 wdt->wdd.max_timeout = 0x10000000U / wdt->rate;
264 wdt->wdd.parent = dev;
265 wdt->layout = data->offset;
266
267 if (readl(wdt_addr(wdt, WDT_STS)) & 1)
268 wdt->wdd.bootstatus = WDIOF_CARDRESET;
269
270 /*
271 * If 'timeout-sec' unspecified in devicetree, assume a 30 second
272 * default, unless the max timeout is less than 30 seconds, then use
273 * the max instead.
274 */
275 wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U);
276 watchdog_init_timeout(&wdt->wdd, 0, dev);
277
278 /*
279 * If WDT is already running, call WDT start which
280 * will stop the WDT, set timeouts as bootloader
281 * might use different ones and set running bit
282 * to inform the WDT subsystem to ping the WDT
283 */
284 if (qcom_wdt_is_running(&wdt->wdd)) {
285 qcom_wdt_start(&wdt->wdd);
286 set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
287 }
288
289 ret = devm_watchdog_register_device(dev, &wdt->wdd);
290 if (ret)
291 return ret;
292
293 platform_set_drvdata(pdev, wdt);
294 return 0;
295}
296
297static int __maybe_unused qcom_wdt_suspend(struct device *dev)
298{
299 struct qcom_wdt *wdt = dev_get_drvdata(dev);
300
301 if (watchdog_active(&wdt->wdd))
302 qcom_wdt_stop(&wdt->wdd);
303
304 return 0;
305}
306
307static int __maybe_unused qcom_wdt_resume(struct device *dev)
308{
309 struct qcom_wdt *wdt = dev_get_drvdata(dev);
310
311 if (watchdog_active(&wdt->wdd))
312 qcom_wdt_start(&wdt->wdd);
313
314 return 0;
315}
316
317static const struct dev_pm_ops qcom_wdt_pm_ops = {
318 SET_LATE_SYSTEM_SLEEP_PM_OPS(qcom_wdt_suspend, qcom_wdt_resume)
319};
320
321static const struct of_device_id qcom_wdt_of_table[] = {
322 { .compatible = "qcom,kpss-timer", .data = &match_data_apcs_tmr },
323 { .compatible = "qcom,scss-timer", .data = &match_data_apcs_tmr },
324 { .compatible = "qcom,kpss-wdt", .data = &match_data_kpss },
325 { },
326};
327MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
328
329static struct platform_driver qcom_watchdog_driver = {
330 .probe = qcom_wdt_probe,
331 .driver = {
332 .name = KBUILD_MODNAME,
333 .of_match_table = qcom_wdt_of_table,
334 .pm = &qcom_wdt_pm_ops,
335 },
336};
337module_platform_driver(qcom_watchdog_driver);
338
339MODULE_DESCRIPTION("QCOM KPSS Watchdog Driver");
340MODULE_LICENSE("GPL v2");
1/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 */
13#include <linux/clk.h>
14#include <linux/delay.h>
15#include <linux/io.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/watchdog.h>
21
22#define WDT_RST 0x38
23#define WDT_EN 0x40
24#define WDT_BITE_TIME 0x5C
25
26struct qcom_wdt {
27 struct watchdog_device wdd;
28 struct clk *clk;
29 unsigned long rate;
30 void __iomem *base;
31};
32
33static inline
34struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd)
35{
36 return container_of(wdd, struct qcom_wdt, wdd);
37}
38
39static int qcom_wdt_start(struct watchdog_device *wdd)
40{
41 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
42
43 writel(0, wdt->base + WDT_EN);
44 writel(1, wdt->base + WDT_RST);
45 writel(wdd->timeout * wdt->rate, wdt->base + WDT_BITE_TIME);
46 writel(1, wdt->base + WDT_EN);
47 return 0;
48}
49
50static int qcom_wdt_stop(struct watchdog_device *wdd)
51{
52 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
53
54 writel(0, wdt->base + WDT_EN);
55 return 0;
56}
57
58static int qcom_wdt_ping(struct watchdog_device *wdd)
59{
60 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
61
62 writel(1, wdt->base + WDT_RST);
63 return 0;
64}
65
66static int qcom_wdt_set_timeout(struct watchdog_device *wdd,
67 unsigned int timeout)
68{
69 wdd->timeout = timeout;
70 return qcom_wdt_start(wdd);
71}
72
73static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action,
74 void *data)
75{
76 struct qcom_wdt *wdt = to_qcom_wdt(wdd);
77 u32 timeout;
78
79 /*
80 * Trigger watchdog bite:
81 * Setup BITE_TIME to be 128ms, and enable WDT.
82 */
83 timeout = 128 * wdt->rate / 1000;
84
85 writel(0, wdt->base + WDT_EN);
86 writel(1, wdt->base + WDT_RST);
87 writel(timeout, wdt->base + WDT_BITE_TIME);
88 writel(1, wdt->base + WDT_EN);
89
90 /*
91 * Actually make sure the above sequence hits hardware before sleeping.
92 */
93 wmb();
94
95 msleep(150);
96 return 0;
97}
98
99static const struct watchdog_ops qcom_wdt_ops = {
100 .start = qcom_wdt_start,
101 .stop = qcom_wdt_stop,
102 .ping = qcom_wdt_ping,
103 .set_timeout = qcom_wdt_set_timeout,
104 .restart = qcom_wdt_restart,
105 .owner = THIS_MODULE,
106};
107
108static const struct watchdog_info qcom_wdt_info = {
109 .options = WDIOF_KEEPALIVEPING
110 | WDIOF_MAGICCLOSE
111 | WDIOF_SETTIMEOUT,
112 .identity = KBUILD_MODNAME,
113};
114
115static int qcom_wdt_probe(struct platform_device *pdev)
116{
117 struct qcom_wdt *wdt;
118 struct resource *res;
119 struct device_node *np = pdev->dev.of_node;
120 u32 percpu_offset;
121 int ret;
122
123 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
124 if (!wdt)
125 return -ENOMEM;
126
127 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
128
129 /* We use CPU0's DGT for the watchdog */
130 if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
131 percpu_offset = 0;
132
133 res->start += percpu_offset;
134 res->end += percpu_offset;
135
136 wdt->base = devm_ioremap_resource(&pdev->dev, res);
137 if (IS_ERR(wdt->base))
138 return PTR_ERR(wdt->base);
139
140 wdt->clk = devm_clk_get(&pdev->dev, NULL);
141 if (IS_ERR(wdt->clk)) {
142 dev_err(&pdev->dev, "failed to get input clock\n");
143 return PTR_ERR(wdt->clk);
144 }
145
146 ret = clk_prepare_enable(wdt->clk);
147 if (ret) {
148 dev_err(&pdev->dev, "failed to setup clock\n");
149 return ret;
150 }
151
152 /*
153 * We use the clock rate to calculate the max timeout, so ensure it's
154 * not zero to avoid a divide-by-zero exception.
155 *
156 * WATCHDOG_CORE assumes units of seconds, if the WDT is clocked such
157 * that it would bite before a second elapses it's usefulness is
158 * limited. Bail if this is the case.
159 */
160 wdt->rate = clk_get_rate(wdt->clk);
161 if (wdt->rate == 0 ||
162 wdt->rate > 0x10000000U) {
163 dev_err(&pdev->dev, "invalid clock rate\n");
164 ret = -EINVAL;
165 goto err_clk_unprepare;
166 }
167
168 wdt->wdd.info = &qcom_wdt_info;
169 wdt->wdd.ops = &qcom_wdt_ops;
170 wdt->wdd.min_timeout = 1;
171 wdt->wdd.max_timeout = 0x10000000U / wdt->rate;
172 wdt->wdd.parent = &pdev->dev;
173
174 /*
175 * If 'timeout-sec' unspecified in devicetree, assume a 30 second
176 * default, unless the max timeout is less than 30 seconds, then use
177 * the max instead.
178 */
179 wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U);
180 watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev);
181
182 ret = watchdog_register_device(&wdt->wdd);
183 if (ret) {
184 dev_err(&pdev->dev, "failed to register watchdog\n");
185 goto err_clk_unprepare;
186 }
187
188 platform_set_drvdata(pdev, wdt);
189 return 0;
190
191err_clk_unprepare:
192 clk_disable_unprepare(wdt->clk);
193 return ret;
194}
195
196static int qcom_wdt_remove(struct platform_device *pdev)
197{
198 struct qcom_wdt *wdt = platform_get_drvdata(pdev);
199
200 watchdog_unregister_device(&wdt->wdd);
201 clk_disable_unprepare(wdt->clk);
202 return 0;
203}
204
205static const struct of_device_id qcom_wdt_of_table[] = {
206 { .compatible = "qcom,kpss-timer" },
207 { .compatible = "qcom,scss-timer" },
208 { },
209};
210MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
211
212static struct platform_driver qcom_watchdog_driver = {
213 .probe = qcom_wdt_probe,
214 .remove = qcom_wdt_remove,
215 .driver = {
216 .name = KBUILD_MODNAME,
217 .of_match_table = qcom_wdt_of_table,
218 },
219};
220module_platform_driver(qcom_watchdog_driver);
221
222MODULE_DESCRIPTION("QCOM KPSS Watchdog Driver");
223MODULE_LICENSE("GPL v2");