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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * sunxi Watchdog Driver
4 *
5 * Copyright (c) 2013 Carlo Caione
6 * 2012 Henrik Nordstrom
7 *
8 * Based on xen_wdt.c
9 * (c) Copyright 2010 Novell, Inc.
10 */
11
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/moduleparam.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/types.h>
23#include <linux/watchdog.h>
24
25#define WDT_MAX_TIMEOUT 16
26#define WDT_MIN_TIMEOUT 1
27#define WDT_TIMEOUT_MASK 0x0F
28
29#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
30
31#define WDT_MODE_EN (1 << 0)
32
33#define DRV_NAME "sunxi-wdt"
34#define DRV_VERSION "1.0"
35
36static bool nowayout = WATCHDOG_NOWAYOUT;
37static unsigned int timeout;
38
39/*
40 * This structure stores the register offsets for different variants
41 * of Allwinner's watchdog hardware.
42 */
43struct sunxi_wdt_reg {
44 u8 wdt_ctrl;
45 u8 wdt_cfg;
46 u8 wdt_mode;
47 u8 wdt_timeout_shift;
48 u8 wdt_reset_mask;
49 u8 wdt_reset_val;
50 u32 wdt_key_val;
51};
52
53struct sunxi_wdt_dev {
54 struct watchdog_device wdt_dev;
55 void __iomem *wdt_base;
56 const struct sunxi_wdt_reg *wdt_regs;
57};
58
59/*
60 * wdt_timeout_map maps the watchdog timer interval value in seconds to
61 * the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3
62 *
63 * [timeout seconds] = register value
64 *
65 */
66
67static const int wdt_timeout_map[] = {
68 [1] = 0x1, /* 1s */
69 [2] = 0x2, /* 2s */
70 [3] = 0x3, /* 3s */
71 [4] = 0x4, /* 4s */
72 [5] = 0x5, /* 5s */
73 [6] = 0x6, /* 6s */
74 [8] = 0x7, /* 8s */
75 [10] = 0x8, /* 10s */
76 [12] = 0x9, /* 12s */
77 [14] = 0xA, /* 14s */
78 [16] = 0xB, /* 16s */
79};
80
81
82static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
83 unsigned long action, void *data)
84{
85 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
86 void __iomem *wdt_base = sunxi_wdt->wdt_base;
87 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
88 u32 val;
89
90 /* Set system reset function */
91 val = readl(wdt_base + regs->wdt_cfg);
92 val &= ~(regs->wdt_reset_mask);
93 val |= regs->wdt_reset_val;
94 val |= regs->wdt_key_val;
95 writel(val, wdt_base + regs->wdt_cfg);
96
97 /* Set lowest timeout and enable watchdog */
98 val = readl(wdt_base + regs->wdt_mode);
99 val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
100 val |= WDT_MODE_EN;
101 val |= regs->wdt_key_val;
102 writel(val, wdt_base + regs->wdt_mode);
103
104 /*
105 * Restart the watchdog. The default (and lowest) interval
106 * value for the watchdog is 0.5s.
107 */
108 writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
109
110 while (1) {
111 mdelay(5);
112 val = readl(wdt_base + regs->wdt_mode);
113 val |= WDT_MODE_EN;
114 val |= regs->wdt_key_val;
115 writel(val, wdt_base + regs->wdt_mode);
116 }
117 return 0;
118}
119
120static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
121{
122 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
123 void __iomem *wdt_base = sunxi_wdt->wdt_base;
124 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
125
126 writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
127
128 return 0;
129}
130
131static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
132 unsigned int timeout)
133{
134 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
135 void __iomem *wdt_base = sunxi_wdt->wdt_base;
136 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
137 u32 reg;
138
139 if (wdt_timeout_map[timeout] == 0)
140 timeout++;
141
142 sunxi_wdt->wdt_dev.timeout = timeout;
143
144 reg = readl(wdt_base + regs->wdt_mode);
145 reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
146 reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
147 reg |= regs->wdt_key_val;
148 writel(reg, wdt_base + regs->wdt_mode);
149
150 sunxi_wdt_ping(wdt_dev);
151
152 return 0;
153}
154
155static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
156{
157 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
158 void __iomem *wdt_base = sunxi_wdt->wdt_base;
159 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
160
161 writel(regs->wdt_key_val, wdt_base + regs->wdt_mode);
162
163 return 0;
164}
165
166static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
167{
168 u32 reg;
169 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
170 void __iomem *wdt_base = sunxi_wdt->wdt_base;
171 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
172 int ret;
173
174 ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
175 sunxi_wdt->wdt_dev.timeout);
176 if (ret < 0)
177 return ret;
178
179 /* Set system reset function */
180 reg = readl(wdt_base + regs->wdt_cfg);
181 reg &= ~(regs->wdt_reset_mask);
182 reg |= regs->wdt_reset_val;
183 reg |= regs->wdt_key_val;
184 writel(reg, wdt_base + regs->wdt_cfg);
185
186 /* Enable watchdog */
187 reg = readl(wdt_base + regs->wdt_mode);
188 reg |= WDT_MODE_EN;
189 reg |= regs->wdt_key_val;
190 writel(reg, wdt_base + regs->wdt_mode);
191
192 return 0;
193}
194
195static const struct watchdog_info sunxi_wdt_info = {
196 .identity = DRV_NAME,
197 .options = WDIOF_SETTIMEOUT |
198 WDIOF_KEEPALIVEPING |
199 WDIOF_MAGICCLOSE,
200};
201
202static const struct watchdog_ops sunxi_wdt_ops = {
203 .owner = THIS_MODULE,
204 .start = sunxi_wdt_start,
205 .stop = sunxi_wdt_stop,
206 .ping = sunxi_wdt_ping,
207 .set_timeout = sunxi_wdt_set_timeout,
208 .restart = sunxi_wdt_restart,
209};
210
211static const struct sunxi_wdt_reg sun4i_wdt_reg = {
212 .wdt_ctrl = 0x00,
213 .wdt_cfg = 0x04,
214 .wdt_mode = 0x04,
215 .wdt_timeout_shift = 3,
216 .wdt_reset_mask = 0x02,
217 .wdt_reset_val = 0x02,
218};
219
220static const struct sunxi_wdt_reg sun6i_wdt_reg = {
221 .wdt_ctrl = 0x10,
222 .wdt_cfg = 0x14,
223 .wdt_mode = 0x18,
224 .wdt_timeout_shift = 4,
225 .wdt_reset_mask = 0x03,
226 .wdt_reset_val = 0x01,
227};
228
229static const struct sunxi_wdt_reg sun20i_wdt_reg = {
230 .wdt_ctrl = 0x10,
231 .wdt_cfg = 0x14,
232 .wdt_mode = 0x18,
233 .wdt_timeout_shift = 4,
234 .wdt_reset_mask = 0x03,
235 .wdt_reset_val = 0x01,
236 .wdt_key_val = 0x16aa0000,
237};
238
239static const struct of_device_id sunxi_wdt_dt_ids[] = {
240 { .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
241 { .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
242 { .compatible = "allwinner,sun20i-d1-wdt", .data = &sun20i_wdt_reg },
243 { /* sentinel */ }
244};
245MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
246
247static int sunxi_wdt_probe(struct platform_device *pdev)
248{
249 struct device *dev = &pdev->dev;
250 struct sunxi_wdt_dev *sunxi_wdt;
251 int err;
252
253 sunxi_wdt = devm_kzalloc(dev, sizeof(*sunxi_wdt), GFP_KERNEL);
254 if (!sunxi_wdt)
255 return -ENOMEM;
256
257 sunxi_wdt->wdt_regs = of_device_get_match_data(dev);
258 if (!sunxi_wdt->wdt_regs)
259 return -ENODEV;
260
261 sunxi_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
262 if (IS_ERR(sunxi_wdt->wdt_base))
263 return PTR_ERR(sunxi_wdt->wdt_base);
264
265 sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
266 sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
267 sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
268 sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
269 sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
270 sunxi_wdt->wdt_dev.parent = dev;
271
272 watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, dev);
273 watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
274 watchdog_set_restart_priority(&sunxi_wdt->wdt_dev, 128);
275
276 watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
277
278 sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
279
280 watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
281 err = devm_watchdog_register_device(dev, &sunxi_wdt->wdt_dev);
282 if (unlikely(err))
283 return err;
284
285 dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
286 sunxi_wdt->wdt_dev.timeout, nowayout);
287
288 return 0;
289}
290
291static struct platform_driver sunxi_wdt_driver = {
292 .probe = sunxi_wdt_probe,
293 .driver = {
294 .name = DRV_NAME,
295 .of_match_table = sunxi_wdt_dt_ids,
296 },
297};
298
299module_platform_driver(sunxi_wdt_driver);
300
301module_param(timeout, uint, 0);
302MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
303
304module_param(nowayout, bool, 0);
305MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
306 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
307
308MODULE_LICENSE("GPL");
309MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
310MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
311MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
312MODULE_VERSION(DRV_VERSION);
1/*
2 * sunxi Watchdog Driver
3 *
4 * Copyright (c) 2013 Carlo Caione
5 * 2012 Henrik Nordstrom
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Based on xen_wdt.c
13 * (c) Copyright 2010 Novell, Inc.
14 */
15
16#include <linux/clk.h>
17#include <linux/err.h>
18#include <linux/init.h>
19#include <linux/io.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
23#include <linux/of.h>
24#include <linux/platform_device.h>
25#include <linux/types.h>
26#include <linux/watchdog.h>
27
28#define WDT_MAX_TIMEOUT 16
29#define WDT_MIN_TIMEOUT 1
30#define WDT_MODE_TIMEOUT(n) ((n) << 3)
31#define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F)
32
33#define WDT_CTRL 0x00
34#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
35
36#define WDT_MODE 0x04
37#define WDT_MODE_EN (1 << 0)
38#define WDT_MODE_RST_EN (1 << 1)
39
40#define DRV_NAME "sunxi-wdt"
41#define DRV_VERSION "1.0"
42
43static bool nowayout = WATCHDOG_NOWAYOUT;
44static unsigned int timeout = WDT_MAX_TIMEOUT;
45
46struct sunxi_wdt_dev {
47 struct watchdog_device wdt_dev;
48 void __iomem *wdt_base;
49};
50
51/*
52 * wdt_timeout_map maps the watchdog timer interval value in seconds to
53 * the value of the register WDT_MODE bit 3:6
54 *
55 * [timeout seconds] = register value
56 *
57 */
58
59static const int wdt_timeout_map[] = {
60 [1] = 0b0001, /* 1s */
61 [2] = 0b0010, /* 2s */
62 [3] = 0b0011, /* 3s */
63 [4] = 0b0100, /* 4s */
64 [5] = 0b0101, /* 5s */
65 [6] = 0b0110, /* 6s */
66 [8] = 0b0111, /* 8s */
67 [10] = 0b1000, /* 10s */
68 [12] = 0b1001, /* 12s */
69 [14] = 0b1010, /* 14s */
70 [16] = 0b1011, /* 16s */
71};
72
73static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
74{
75 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
76 void __iomem *wdt_base = sunxi_wdt->wdt_base;
77
78 iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);
79
80 return 0;
81}
82
83static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
84 unsigned int timeout)
85{
86 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
87 void __iomem *wdt_base = sunxi_wdt->wdt_base;
88 u32 reg;
89
90 if (wdt_timeout_map[timeout] == 0)
91 timeout++;
92
93 sunxi_wdt->wdt_dev.timeout = timeout;
94
95 reg = ioread32(wdt_base + WDT_MODE);
96 reg &= ~WDT_TIMEOUT_MASK;
97 reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]);
98 iowrite32(reg, wdt_base + WDT_MODE);
99
100 sunxi_wdt_ping(wdt_dev);
101
102 return 0;
103}
104
105static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
106{
107 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
108 void __iomem *wdt_base = sunxi_wdt->wdt_base;
109
110 iowrite32(0, wdt_base + WDT_MODE);
111
112 return 0;
113}
114
115static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
116{
117 u32 reg;
118 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
119 void __iomem *wdt_base = sunxi_wdt->wdt_base;
120 int ret;
121
122 ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
123 sunxi_wdt->wdt_dev.timeout);
124 if (ret < 0)
125 return ret;
126
127 reg = ioread32(wdt_base + WDT_MODE);
128 reg |= (WDT_MODE_RST_EN | WDT_MODE_EN);
129 iowrite32(reg, wdt_base + WDT_MODE);
130
131 return 0;
132}
133
134static const struct watchdog_info sunxi_wdt_info = {
135 .identity = DRV_NAME,
136 .options = WDIOF_SETTIMEOUT |
137 WDIOF_KEEPALIVEPING |
138 WDIOF_MAGICCLOSE,
139};
140
141static const struct watchdog_ops sunxi_wdt_ops = {
142 .owner = THIS_MODULE,
143 .start = sunxi_wdt_start,
144 .stop = sunxi_wdt_stop,
145 .ping = sunxi_wdt_ping,
146 .set_timeout = sunxi_wdt_set_timeout,
147};
148
149static int sunxi_wdt_probe(struct platform_device *pdev)
150{
151 struct sunxi_wdt_dev *sunxi_wdt;
152 struct resource *res;
153 int err;
154
155 sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
156 if (!sunxi_wdt)
157 return -EINVAL;
158
159 platform_set_drvdata(pdev, sunxi_wdt);
160
161 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
162 sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
163 if (IS_ERR(sunxi_wdt->wdt_base))
164 return PTR_ERR(sunxi_wdt->wdt_base);
165
166 sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
167 sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
168 sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
169 sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
170 sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
171 sunxi_wdt->wdt_dev.parent = &pdev->dev;
172
173 watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
174 watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
175
176 watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
177
178 sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
179
180 err = watchdog_register_device(&sunxi_wdt->wdt_dev);
181 if (unlikely(err))
182 return err;
183
184 dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
185 sunxi_wdt->wdt_dev.timeout, nowayout);
186
187 return 0;
188}
189
190static int sunxi_wdt_remove(struct platform_device *pdev)
191{
192 struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
193
194 watchdog_unregister_device(&sunxi_wdt->wdt_dev);
195 watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);
196
197 return 0;
198}
199
200static void sunxi_wdt_shutdown(struct platform_device *pdev)
201{
202 struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
203
204 sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
205}
206
207static const struct of_device_id sunxi_wdt_dt_ids[] = {
208 { .compatible = "allwinner,sun4i-a10-wdt" },
209 { /* sentinel */ }
210};
211MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
212
213static struct platform_driver sunxi_wdt_driver = {
214 .probe = sunxi_wdt_probe,
215 .remove = sunxi_wdt_remove,
216 .shutdown = sunxi_wdt_shutdown,
217 .driver = {
218 .owner = THIS_MODULE,
219 .name = DRV_NAME,
220 .of_match_table = sunxi_wdt_dt_ids,
221 },
222};
223
224module_platform_driver(sunxi_wdt_driver);
225
226module_param(timeout, uint, 0);
227MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
228
229module_param(nowayout, bool, 0);
230MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
231 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
232
233MODULE_LICENSE("GPL");
234MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
235MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
236MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
237MODULE_VERSION(DRV_VERSION);