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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Meson Watchdog Driver
4 *
5 * Copyright (c) 2014 Carlo Caione
6 */
7
8#include <linux/clk.h>
9#include <linux/delay.h>
10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/io.h>
13#include <linux/kernel.h>
14#include <linux/mod_devicetable.h>
15#include <linux/module.h>
16#include <linux/moduleparam.h>
17#include <linux/platform_device.h>
18#include <linux/property.h>
19#include <linux/types.h>
20#include <linux/watchdog.h>
21
22#define DRV_NAME "meson_wdt"
23
24#define MESON_WDT_TC 0x00
25#define MESON_WDT_DC_RESET (3 << 24)
26
27#define MESON_WDT_RESET 0x04
28
29#define MESON_WDT_TIMEOUT 30
30#define MESON_WDT_MIN_TIMEOUT 1
31
32#define MESON_SEC_TO_TC(s, c) ((s) * (c))
33
34static bool nowayout = WATCHDOG_NOWAYOUT;
35static unsigned int timeout;
36
37struct meson_wdt_data {
38 unsigned int enable;
39 unsigned int terminal_count_mask;
40 unsigned int count_unit;
41};
42
43static struct meson_wdt_data meson6_wdt_data = {
44 .enable = BIT(22),
45 .terminal_count_mask = 0x3fffff,
46 .count_unit = 100000, /* 10 us */
47};
48
49static struct meson_wdt_data meson8b_wdt_data = {
50 .enable = BIT(19),
51 .terminal_count_mask = 0xffff,
52 .count_unit = 7812, /* 128 us */
53};
54
55struct meson_wdt_dev {
56 struct watchdog_device wdt_dev;
57 void __iomem *wdt_base;
58 const struct meson_wdt_data *data;
59};
60
61static int meson_wdt_restart(struct watchdog_device *wdt_dev,
62 unsigned long action, void *data)
63{
64 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
65 u32 tc_reboot = MESON_WDT_DC_RESET;
66
67 tc_reboot |= meson_wdt->data->enable;
68
69 while (1) {
70 writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
71 mdelay(5);
72 }
73
74 return 0;
75}
76
77static int meson_wdt_ping(struct watchdog_device *wdt_dev)
78{
79 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
80
81 writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
82
83 return 0;
84}
85
86static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
87 unsigned int timeout)
88{
89 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
90 u32 reg;
91
92 reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
93 reg &= ~meson_wdt->data->terminal_count_mask;
94 reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
95 writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
96}
97
98static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
99 unsigned int timeout)
100{
101 wdt_dev->timeout = timeout;
102
103 meson_wdt_change_timeout(wdt_dev, timeout);
104 meson_wdt_ping(wdt_dev);
105
106 return 0;
107}
108
109static int meson_wdt_stop(struct watchdog_device *wdt_dev)
110{
111 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
112 u32 reg;
113
114 reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
115 reg &= ~meson_wdt->data->enable;
116 writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
117
118 return 0;
119}
120
121static int meson_wdt_start(struct watchdog_device *wdt_dev)
122{
123 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
124 u32 reg;
125
126 meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
127 meson_wdt_ping(wdt_dev);
128
129 reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
130 reg |= meson_wdt->data->enable;
131 writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
132
133 return 0;
134}
135
136static const struct watchdog_info meson_wdt_info = {
137 .identity = DRV_NAME,
138 .options = WDIOF_SETTIMEOUT |
139 WDIOF_KEEPALIVEPING |
140 WDIOF_MAGICCLOSE,
141};
142
143static const struct watchdog_ops meson_wdt_ops = {
144 .owner = THIS_MODULE,
145 .start = meson_wdt_start,
146 .stop = meson_wdt_stop,
147 .ping = meson_wdt_ping,
148 .set_timeout = meson_wdt_set_timeout,
149 .restart = meson_wdt_restart,
150};
151
152static const struct of_device_id meson_wdt_dt_ids[] = {
153 { .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
154 { .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
155 { .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
156 { .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
157 { /* sentinel */ }
158};
159MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
160
161static int meson_wdt_probe(struct platform_device *pdev)
162{
163 struct device *dev = &pdev->dev;
164 struct meson_wdt_dev *meson_wdt;
165 int err;
166
167 meson_wdt = devm_kzalloc(dev, sizeof(*meson_wdt), GFP_KERNEL);
168 if (!meson_wdt)
169 return -ENOMEM;
170
171 meson_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
172 if (IS_ERR(meson_wdt->wdt_base))
173 return PTR_ERR(meson_wdt->wdt_base);
174
175 meson_wdt->data = device_get_match_data(dev);
176
177 meson_wdt->wdt_dev.parent = dev;
178 meson_wdt->wdt_dev.info = &meson_wdt_info;
179 meson_wdt->wdt_dev.ops = &meson_wdt_ops;
180 meson_wdt->wdt_dev.max_timeout =
181 meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
182 meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
183 meson_wdt->wdt_dev.timeout = min_t(unsigned int,
184 MESON_WDT_TIMEOUT,
185 meson_wdt->wdt_dev.max_timeout);
186
187 watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
188
189 watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, dev);
190 watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
191 watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
192
193 meson_wdt_stop(&meson_wdt->wdt_dev);
194
195 watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
196 err = devm_watchdog_register_device(dev, &meson_wdt->wdt_dev);
197 if (err)
198 return err;
199
200 dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
201 meson_wdt->wdt_dev.timeout, nowayout);
202
203 return 0;
204}
205
206static struct platform_driver meson_wdt_driver = {
207 .probe = meson_wdt_probe,
208 .driver = {
209 .name = DRV_NAME,
210 .of_match_table = meson_wdt_dt_ids,
211 },
212};
213
214module_platform_driver(meson_wdt_driver);
215
216module_param(timeout, uint, 0);
217MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
218
219module_param(nowayout, bool, 0);
220MODULE_PARM_DESC(nowayout,
221 "Watchdog cannot be stopped once started (default="
222 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
223
224MODULE_LICENSE("GPL");
225MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
226MODULE_DESCRIPTION("Meson Watchdog Timer Driver");
1/*
2 * Meson Watchdog Driver
3 *
4 * Copyright (c) 2014 Carlo Caione
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
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/of_device.h>
22#include <linux/platform_device.h>
23#include <linux/types.h>
24#include <linux/watchdog.h>
25
26#define DRV_NAME "meson_wdt"
27
28#define MESON_WDT_TC 0x00
29#define MESON_WDT_DC_RESET (3 << 24)
30
31#define MESON_WDT_RESET 0x04
32
33#define MESON_WDT_TIMEOUT 30
34#define MESON_WDT_MIN_TIMEOUT 1
35
36#define MESON_SEC_TO_TC(s, c) ((s) * (c))
37
38static bool nowayout = WATCHDOG_NOWAYOUT;
39static unsigned int timeout = MESON_WDT_TIMEOUT;
40
41struct meson_wdt_data {
42 unsigned int enable;
43 unsigned int terminal_count_mask;
44 unsigned int count_unit;
45};
46
47static struct meson_wdt_data meson6_wdt_data = {
48 .enable = BIT(22),
49 .terminal_count_mask = 0x3fffff,
50 .count_unit = 100000, /* 10 us */
51};
52
53static struct meson_wdt_data meson8b_wdt_data = {
54 .enable = BIT(19),
55 .terminal_count_mask = 0xffff,
56 .count_unit = 7812, /* 128 us */
57};
58
59struct meson_wdt_dev {
60 struct watchdog_device wdt_dev;
61 void __iomem *wdt_base;
62 const struct meson_wdt_data *data;
63};
64
65static int meson_wdt_restart(struct watchdog_device *wdt_dev,
66 unsigned long action, void *data)
67{
68 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
69 u32 tc_reboot = MESON_WDT_DC_RESET;
70
71 tc_reboot |= meson_wdt->data->enable;
72
73 while (1) {
74 writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
75 mdelay(5);
76 }
77
78 return 0;
79}
80
81static int meson_wdt_ping(struct watchdog_device *wdt_dev)
82{
83 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
84
85 writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
86
87 return 0;
88}
89
90static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
91 unsigned int timeout)
92{
93 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
94 u32 reg;
95
96 reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
97 reg &= ~meson_wdt->data->terminal_count_mask;
98 reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
99 writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
100}
101
102static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
103 unsigned int timeout)
104{
105 wdt_dev->timeout = timeout;
106
107 meson_wdt_change_timeout(wdt_dev, timeout);
108 meson_wdt_ping(wdt_dev);
109
110 return 0;
111}
112
113static int meson_wdt_stop(struct watchdog_device *wdt_dev)
114{
115 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
116 u32 reg;
117
118 reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
119 reg &= ~meson_wdt->data->enable;
120 writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
121
122 return 0;
123}
124
125static int meson_wdt_start(struct watchdog_device *wdt_dev)
126{
127 struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
128 u32 reg;
129
130 meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
131 meson_wdt_ping(wdt_dev);
132
133 reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
134 reg |= meson_wdt->data->enable;
135 writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
136
137 return 0;
138}
139
140static const struct watchdog_info meson_wdt_info = {
141 .identity = DRV_NAME,
142 .options = WDIOF_SETTIMEOUT |
143 WDIOF_KEEPALIVEPING |
144 WDIOF_MAGICCLOSE,
145};
146
147static const struct watchdog_ops meson_wdt_ops = {
148 .owner = THIS_MODULE,
149 .start = meson_wdt_start,
150 .stop = meson_wdt_stop,
151 .ping = meson_wdt_ping,
152 .set_timeout = meson_wdt_set_timeout,
153 .restart = meson_wdt_restart,
154};
155
156static const struct of_device_id meson_wdt_dt_ids[] = {
157 { .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
158 { .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
159 { /* sentinel */ }
160};
161MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
162
163static int meson_wdt_probe(struct platform_device *pdev)
164{
165 struct resource *res;
166 struct meson_wdt_dev *meson_wdt;
167 const struct of_device_id *of_id;
168 int err;
169
170 meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL);
171 if (!meson_wdt)
172 return -ENOMEM;
173
174 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
175 meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
176 if (IS_ERR(meson_wdt->wdt_base))
177 return PTR_ERR(meson_wdt->wdt_base);
178
179 of_id = of_match_device(meson_wdt_dt_ids, &pdev->dev);
180 if (!of_id) {
181 dev_err(&pdev->dev, "Unable to initialize WDT data\n");
182 return -ENODEV;
183 }
184 meson_wdt->data = of_id->data;
185
186 meson_wdt->wdt_dev.parent = &pdev->dev;
187 meson_wdt->wdt_dev.info = &meson_wdt_info;
188 meson_wdt->wdt_dev.ops = &meson_wdt_ops;
189 meson_wdt->wdt_dev.max_timeout =
190 meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
191 meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
192 meson_wdt->wdt_dev.timeout = min_t(unsigned int,
193 MESON_WDT_TIMEOUT,
194 meson_wdt->wdt_dev.max_timeout);
195
196 watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
197
198 watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev);
199 watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
200 watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
201
202 meson_wdt_stop(&meson_wdt->wdt_dev);
203
204 err = watchdog_register_device(&meson_wdt->wdt_dev);
205 if (err)
206 return err;
207
208 platform_set_drvdata(pdev, meson_wdt);
209
210 dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
211 meson_wdt->wdt_dev.timeout, nowayout);
212
213 return 0;
214}
215
216static int meson_wdt_remove(struct platform_device *pdev)
217{
218 struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev);
219
220 watchdog_unregister_device(&meson_wdt->wdt_dev);
221
222 return 0;
223}
224
225static void meson_wdt_shutdown(struct platform_device *pdev)
226{
227 struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev);
228
229 meson_wdt_stop(&meson_wdt->wdt_dev);
230}
231
232static struct platform_driver meson_wdt_driver = {
233 .probe = meson_wdt_probe,
234 .remove = meson_wdt_remove,
235 .shutdown = meson_wdt_shutdown,
236 .driver = {
237 .name = DRV_NAME,
238 .of_match_table = meson_wdt_dt_ids,
239 },
240};
241
242module_platform_driver(meson_wdt_driver);
243
244module_param(timeout, uint, 0);
245MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
246
247module_param(nowayout, bool, 0);
248MODULE_PARM_DESC(nowayout,
249 "Watchdog cannot be stopped once started (default="
250 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
251
252MODULE_LICENSE("GPL");
253MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
254MODULE_DESCRIPTION("Meson Watchdog Timer Driver");