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3c910ecb | 1 | // SPDX-License-Identifier: GPL-2.0-only |
22b1c841 BG |
2 | /* |
3 | * Watchdog driver for Ricoh RN5T618 PMIC | |
4 | * | |
5 | * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com> | |
22b1c841 BG |
6 | */ |
7 | ||
8 | #include <linux/device.h> | |
9 | #include <linux/mfd/rn5t618.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/watchdog.h> | |
13 | ||
14 | #define DRIVER_NAME "rn5t618-wdt" | |
15 | ||
16 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
17 | static unsigned int timeout; | |
18 | ||
19 | module_param(timeout, uint, 0); | |
20 | MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds"); | |
21 | ||
22 | module_param(nowayout, bool, 0); | |
23 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | |
24 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
25 | ||
26 | struct rn5t618_wdt { | |
27 | struct watchdog_device wdt_dev; | |
28 | struct rn5t618 *rn5t618; | |
29 | }; | |
30 | ||
31 | /* | |
32 | * This array encodes the values of WDOGTIM field for the supported | |
33 | * watchdog expiration times. If the watchdog is not accessed before | |
34 | * the timer expiration, the PMU generates an interrupt and if the CPU | |
35 | * doesn't clear it within one second the system is restarted. | |
36 | */ | |
37 | static const struct { | |
38 | u8 reg_val; | |
39 | unsigned int time; | |
40 | } rn5t618_wdt_map[] = { | |
41 | { 0, 1 }, | |
42 | { 1, 8 }, | |
43 | { 2, 32 }, | |
44 | { 3, 128 }, | |
45 | }; | |
46 | ||
47 | static int rn5t618_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
48 | unsigned int t) | |
49 | { | |
50 | struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); | |
51 | int ret, i; | |
52 | ||
53 | for (i = 0; i < ARRAY_SIZE(rn5t618_wdt_map); i++) { | |
54 | if (rn5t618_wdt_map[i].time + 1 >= t) | |
55 | break; | |
56 | } | |
57 | ||
58 | if (i == ARRAY_SIZE(rn5t618_wdt_map)) | |
59 | return -EINVAL; | |
60 | ||
61 | ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, | |
62 | RN5T618_WATCHDOG_WDOGTIM_M, | |
63 | rn5t618_wdt_map[i].reg_val); | |
64 | if (!ret) | |
65 | wdt_dev->timeout = rn5t618_wdt_map[i].time; | |
66 | ||
67 | return ret; | |
68 | } | |
69 | ||
70 | static int rn5t618_wdt_start(struct watchdog_device *wdt_dev) | |
71 | { | |
72 | struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); | |
73 | int ret; | |
74 | ||
75 | ret = rn5t618_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
76 | if (ret) | |
77 | return ret; | |
78 | ||
79 | /* enable repower-on */ | |
80 | ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_REPCNT, | |
81 | RN5T618_REPCNT_REPWRON, | |
82 | RN5T618_REPCNT_REPWRON); | |
83 | if (ret) | |
84 | return ret; | |
85 | ||
86 | /* enable watchdog */ | |
87 | ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, | |
88 | RN5T618_WATCHDOG_WDOGEN, | |
89 | RN5T618_WATCHDOG_WDOGEN); | |
90 | if (ret) | |
91 | return ret; | |
92 | ||
93 | /* enable watchdog interrupt */ | |
94 | return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIREN, | |
95 | RN5T618_PWRIRQ_IR_WDOG, | |
96 | RN5T618_PWRIRQ_IR_WDOG); | |
97 | } | |
98 | ||
99 | static int rn5t618_wdt_stop(struct watchdog_device *wdt_dev) | |
100 | { | |
101 | struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); | |
102 | ||
103 | return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, | |
104 | RN5T618_WATCHDOG_WDOGEN, 0); | |
105 | } | |
106 | ||
107 | static int rn5t618_wdt_ping(struct watchdog_device *wdt_dev) | |
108 | { | |
109 | struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); | |
110 | unsigned int val; | |
111 | int ret; | |
112 | ||
113 | /* The counter is restarted after a R/W access to watchdog register */ | |
114 | ret = regmap_read(wdt->rn5t618->regmap, RN5T618_WATCHDOG, &val); | |
115 | if (ret) | |
116 | return ret; | |
117 | ||
118 | ret = regmap_write(wdt->rn5t618->regmap, RN5T618_WATCHDOG, val); | |
119 | if (ret) | |
120 | return ret; | |
121 | ||
122 | /* Clear pending watchdog interrupt */ | |
123 | return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIRQ, | |
124 | RN5T618_PWRIRQ_IR_WDOG, 0); | |
125 | } | |
126 | ||
6c368932 | 127 | static const struct watchdog_info rn5t618_wdt_info = { |
22b1c841 BG |
128 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | |
129 | WDIOF_KEEPALIVEPING, | |
130 | .identity = DRIVER_NAME, | |
131 | }; | |
132 | ||
85f15cfc | 133 | static const struct watchdog_ops rn5t618_wdt_ops = { |
22b1c841 BG |
134 | .owner = THIS_MODULE, |
135 | .start = rn5t618_wdt_start, | |
136 | .stop = rn5t618_wdt_stop, | |
137 | .ping = rn5t618_wdt_ping, | |
138 | .set_timeout = rn5t618_wdt_set_timeout, | |
139 | }; | |
140 | ||
141 | static int rn5t618_wdt_probe(struct platform_device *pdev) | |
142 | { | |
cc718597 GR |
143 | struct device *dev = &pdev->dev; |
144 | struct rn5t618 *rn5t618 = dev_get_drvdata(dev->parent); | |
22b1c841 BG |
145 | struct rn5t618_wdt *wdt; |
146 | int min_timeout, max_timeout; | |
147 | ||
cc718597 | 148 | wdt = devm_kzalloc(dev, sizeof(struct rn5t618_wdt), GFP_KERNEL); |
22b1c841 BG |
149 | if (!wdt) |
150 | return -ENOMEM; | |
151 | ||
152 | min_timeout = rn5t618_wdt_map[0].time; | |
153 | max_timeout = rn5t618_wdt_map[ARRAY_SIZE(rn5t618_wdt_map) - 1].time; | |
154 | ||
155 | wdt->rn5t618 = rn5t618; | |
156 | wdt->wdt_dev.info = &rn5t618_wdt_info; | |
157 | wdt->wdt_dev.ops = &rn5t618_wdt_ops; | |
158 | wdt->wdt_dev.min_timeout = min_timeout; | |
159 | wdt->wdt_dev.max_timeout = max_timeout; | |
160 | wdt->wdt_dev.timeout = max_timeout; | |
cc718597 | 161 | wdt->wdt_dev.parent = dev; |
22b1c841 BG |
162 | |
163 | watchdog_set_drvdata(&wdt->wdt_dev, wdt); | |
cc718597 | 164 | watchdog_init_timeout(&wdt->wdt_dev, timeout, dev); |
22b1c841 BG |
165 | watchdog_set_nowayout(&wdt->wdt_dev, nowayout); |
166 | ||
167 | platform_set_drvdata(pdev, wdt); | |
168 | ||
169 | return watchdog_register_device(&wdt->wdt_dev); | |
170 | } | |
171 | ||
172 | static int rn5t618_wdt_remove(struct platform_device *pdev) | |
173 | { | |
174 | struct rn5t618_wdt *wdt = platform_get_drvdata(pdev); | |
175 | ||
176 | watchdog_unregister_device(&wdt->wdt_dev); | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | static struct platform_driver rn5t618_wdt_driver = { | |
182 | .probe = rn5t618_wdt_probe, | |
183 | .remove = rn5t618_wdt_remove, | |
184 | .driver = { | |
185 | .name = DRIVER_NAME, | |
186 | }, | |
187 | }; | |
188 | ||
189 | module_platform_driver(rn5t618_wdt_driver); | |
190 | ||
a76dfb85 | 191 | MODULE_ALIAS("platform:rn5t618-wdt"); |
22b1c841 BG |
192 | MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>"); |
193 | MODULE_DESCRIPTION("RN5T618 watchdog driver"); | |
194 | MODULE_LICENSE("GPL v2"); |