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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
22e1b8f6 CC |
2 | /* |
3 | * Meson Watchdog Driver | |
4 | * | |
5 | * Copyright (c) 2014 Carlo Caione | |
22e1b8f6 CC |
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/module.h> | |
15 | #include <linux/moduleparam.h> | |
22e1b8f6 | 16 | #include <linux/of.h> |
943bf1f6 | 17 | #include <linux/of_device.h> |
22e1b8f6 | 18 | #include <linux/platform_device.h> |
22e1b8f6 CC |
19 | #include <linux/types.h> |
20 | #include <linux/watchdog.h> | |
21 | ||
22 | #define DRV_NAME "meson_wdt" | |
23 | ||
24 | #define MESON_WDT_TC 0x00 | |
22e1b8f6 CC |
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 | |
22e1b8f6 | 31 | |
943bf1f6 | 32 | #define MESON_SEC_TO_TC(s, c) ((s) * (c)) |
22e1b8f6 CC |
33 | |
34 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
4590d62c | 35 | static unsigned int timeout; |
22e1b8f6 | 36 | |
943bf1f6 CC |
37 | struct meson_wdt_data { |
38 | unsigned int enable; | |
39 | unsigned int terminal_count_mask; | |
40 | unsigned int count_unit; | |
41 | }; | |
42 | ||
43 | static struct meson_wdt_data meson6_wdt_data = { | |
44 | .enable = BIT(22), | |
45 | .terminal_count_mask = 0x3fffff, | |
46 | .count_unit = 100000, /* 10 us */ | |
47 | }; | |
48 | ||
71388840 CC |
49 | static struct meson_wdt_data meson8b_wdt_data = { |
50 | .enable = BIT(19), | |
51 | .terminal_count_mask = 0xffff, | |
52 | .count_unit = 7812, /* 128 us */ | |
53 | }; | |
54 | ||
22e1b8f6 CC |
55 | struct meson_wdt_dev { |
56 | struct watchdog_device wdt_dev; | |
57 | void __iomem *wdt_base; | |
943bf1f6 | 58 | const struct meson_wdt_data *data; |
22e1b8f6 CC |
59 | }; |
60 | ||
4d8b229d GR |
61 | static int meson_wdt_restart(struct watchdog_device *wdt_dev, |
62 | unsigned long action, void *data) | |
22e1b8f6 | 63 | { |
1b6fd59a | 64 | struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); |
943bf1f6 CC |
65 | u32 tc_reboot = MESON_WDT_DC_RESET; |
66 | ||
67 | tc_reboot |= meson_wdt->data->enable; | |
22e1b8f6 CC |
68 | |
69 | while (1) { | |
70 | writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); | |
71 | mdelay(5); | |
72 | } | |
73 | ||
1b6fd59a | 74 | return 0; |
22e1b8f6 CC |
75 | } |
76 | ||
77 | static 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 | ||
86 | static 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); | |
943bf1f6 CC |
93 | reg &= ~meson_wdt->data->terminal_count_mask; |
94 | reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit); | |
22e1b8f6 CC |
95 | writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); |
96 | } | |
97 | ||
98 | static 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 | ||
109 | static 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); | |
943bf1f6 | 115 | reg &= ~meson_wdt->data->enable; |
22e1b8f6 CC |
116 | writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
121 | static 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); | |
943bf1f6 | 130 | reg |= meson_wdt->data->enable; |
22e1b8f6 CC |
131 | writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static const struct watchdog_info meson_wdt_info = { | |
137 | .identity = DRV_NAME, | |
138 | .options = WDIOF_SETTIMEOUT | | |
139 | WDIOF_KEEPALIVEPING | | |
140 | WDIOF_MAGICCLOSE, | |
141 | }; | |
142 | ||
143 | static 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, | |
1b6fd59a | 149 | .restart = meson_wdt_restart, |
22e1b8f6 CC |
150 | }; |
151 | ||
943bf1f6 CC |
152 | static const struct of_device_id meson_wdt_dt_ids[] = { |
153 | { .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data }, | |
43a64e81 | 154 | { .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data }, |
71388840 | 155 | { .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data }, |
43a64e81 | 156 | { .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data }, |
943bf1f6 CC |
157 | { /* sentinel */ } |
158 | }; | |
159 | MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids); | |
160 | ||
22e1b8f6 CC |
161 | static int meson_wdt_probe(struct platform_device *pdev) |
162 | { | |
dd1c66e2 | 163 | struct device *dev = &pdev->dev; |
22e1b8f6 | 164 | struct meson_wdt_dev *meson_wdt; |
943bf1f6 | 165 | const struct of_device_id *of_id; |
22e1b8f6 CC |
166 | int err; |
167 | ||
dd1c66e2 | 168 | meson_wdt = devm_kzalloc(dev, sizeof(*meson_wdt), GFP_KERNEL); |
22e1b8f6 CC |
169 | if (!meson_wdt) |
170 | return -ENOMEM; | |
171 | ||
0f0a6a28 | 172 | meson_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0); |
22e1b8f6 CC |
173 | if (IS_ERR(meson_wdt->wdt_base)) |
174 | return PTR_ERR(meson_wdt->wdt_base); | |
175 | ||
dd1c66e2 | 176 | of_id = of_match_device(meson_wdt_dt_ids, dev); |
943bf1f6 | 177 | if (!of_id) { |
dd1c66e2 | 178 | dev_err(dev, "Unable to initialize WDT data\n"); |
943bf1f6 CC |
179 | return -ENODEV; |
180 | } | |
181 | meson_wdt->data = of_id->data; | |
182 | ||
dd1c66e2 | 183 | meson_wdt->wdt_dev.parent = dev; |
22e1b8f6 CC |
184 | meson_wdt->wdt_dev.info = &meson_wdt_info; |
185 | meson_wdt->wdt_dev.ops = &meson_wdt_ops; | |
943bf1f6 CC |
186 | meson_wdt->wdt_dev.max_timeout = |
187 | meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit; | |
22e1b8f6 | 188 | meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT; |
943bf1f6 CC |
189 | meson_wdt->wdt_dev.timeout = min_t(unsigned int, |
190 | MESON_WDT_TIMEOUT, | |
191 | meson_wdt->wdt_dev.max_timeout); | |
22e1b8f6 CC |
192 | |
193 | watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt); | |
194 | ||
dd1c66e2 | 195 | watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, dev); |
22e1b8f6 | 196 | watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout); |
1b6fd59a | 197 | watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128); |
22e1b8f6 CC |
198 | |
199 | meson_wdt_stop(&meson_wdt->wdt_dev); | |
200 | ||
c8841a60 | 201 | watchdog_stop_on_reboot(&meson_wdt->wdt_dev); |
dd1c66e2 | 202 | err = devm_watchdog_register_device(dev, &meson_wdt->wdt_dev); |
22e1b8f6 CC |
203 | if (err) |
204 | return err; | |
205 | ||
dd1c66e2 | 206 | dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", |
22e1b8f6 CC |
207 | meson_wdt->wdt_dev.timeout, nowayout); |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
22e1b8f6 CC |
212 | static struct platform_driver meson_wdt_driver = { |
213 | .probe = meson_wdt_probe, | |
22e1b8f6 | 214 | .driver = { |
22e1b8f6 CC |
215 | .name = DRV_NAME, |
216 | .of_match_table = meson_wdt_dt_ids, | |
217 | }, | |
218 | }; | |
219 | ||
220 | module_platform_driver(meson_wdt_driver); | |
221 | ||
222 | module_param(timeout, uint, 0); | |
223 | MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); | |
224 | ||
225 | module_param(nowayout, bool, 0); | |
226 | MODULE_PARM_DESC(nowayout, | |
227 | "Watchdog cannot be stopped once started (default=" | |
228 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
229 | ||
230 | MODULE_LICENSE("GPL"); | |
231 | MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); | |
232 | MODULE_DESCRIPTION("Meson Watchdog Timer Driver"); |