1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Watchdog driver for Ricoh RN5T618 PMIC |
4 | * |
5 | * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com> |
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(wdd: 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(map: wdt->rn5t618->regmap, RN5T618_WATCHDOG, |
62 | RN5T618_WATCHDOG_WDOGTIM_M, |
63 | val: 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(wdd: wdt_dev); |
73 | int ret; |
74 | |
75 | ret = rn5t618_wdt_set_timeout(wdt_dev, t: wdt_dev->timeout); |
76 | if (ret) |
77 | return ret; |
78 | |
79 | /* enable repower-on */ |
80 | ret = regmap_update_bits(map: 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(map: 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(map: 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(wdd: wdt_dev); |
102 | |
103 | return regmap_update_bits(map: wdt->rn5t618->regmap, RN5T618_WATCHDOG, |
104 | RN5T618_WATCHDOG_WDOGEN, val: 0); |
105 | } |
106 | |
107 | static int rn5t618_wdt_ping(struct watchdog_device *wdt_dev) |
108 | { |
109 | struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdd: 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(map: wdt->rn5t618->regmap, RN5T618_WATCHDOG, val: &val); |
115 | if (ret) |
116 | return ret; |
117 | |
118 | ret = regmap_write(map: wdt->rn5t618->regmap, RN5T618_WATCHDOG, val); |
119 | if (ret) |
120 | return ret; |
121 | |
122 | /* Clear pending watchdog interrupt */ |
123 | return regmap_update_bits(map: wdt->rn5t618->regmap, RN5T618_PWRIRQ, |
124 | RN5T618_PWRIRQ_IR_WDOG, val: 0); |
125 | } |
126 | |
127 | static const struct watchdog_info rn5t618_wdt_info = { |
128 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | |
129 | WDIOF_KEEPALIVEPING, |
130 | .identity = DRIVER_NAME, |
131 | }; |
132 | |
133 | static const struct watchdog_ops rn5t618_wdt_ops = { |
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 | { |
143 | struct device *dev = &pdev->dev; |
144 | struct rn5t618 *rn5t618 = dev_get_drvdata(dev: dev->parent); |
145 | struct rn5t618_wdt *wdt; |
146 | int min_timeout, max_timeout; |
147 | int ret; |
148 | unsigned int val; |
149 | |
150 | wdt = devm_kzalloc(dev, size: sizeof(struct rn5t618_wdt), GFP_KERNEL); |
151 | if (!wdt) |
152 | return -ENOMEM; |
153 | |
154 | min_timeout = rn5t618_wdt_map[0].time; |
155 | max_timeout = rn5t618_wdt_map[ARRAY_SIZE(rn5t618_wdt_map) - 1].time; |
156 | |
157 | wdt->rn5t618 = rn5t618; |
158 | wdt->wdt_dev.info = &rn5t618_wdt_info; |
159 | wdt->wdt_dev.ops = &rn5t618_wdt_ops; |
160 | wdt->wdt_dev.min_timeout = min_timeout; |
161 | wdt->wdt_dev.max_timeout = max_timeout; |
162 | wdt->wdt_dev.timeout = max_timeout; |
163 | wdt->wdt_dev.parent = dev; |
164 | |
165 | /* Read out previous power-off factor */ |
166 | ret = regmap_read(map: wdt->rn5t618->regmap, RN5T618_POFFHIS, val: &val); |
167 | if (ret) |
168 | return ret; |
169 | |
170 | if (val & RN5T618_POFFHIS_VINDET) |
171 | wdt->wdt_dev.bootstatus = WDIOF_POWERUNDER; |
172 | else if (val & RN5T618_POFFHIS_WDG) |
173 | wdt->wdt_dev.bootstatus = WDIOF_CARDRESET; |
174 | |
175 | watchdog_set_drvdata(wdd: &wdt->wdt_dev, data: wdt); |
176 | watchdog_init_timeout(wdd: &wdt->wdt_dev, timeout_parm: timeout, dev); |
177 | watchdog_set_nowayout(wdd: &wdt->wdt_dev, nowayout); |
178 | |
179 | platform_set_drvdata(pdev, data: wdt); |
180 | |
181 | return devm_watchdog_register_device(dev, &wdt->wdt_dev); |
182 | } |
183 | |
184 | static struct platform_driver rn5t618_wdt_driver = { |
185 | .probe = rn5t618_wdt_probe, |
186 | .driver = { |
187 | .name = DRIVER_NAME, |
188 | }, |
189 | }; |
190 | |
191 | module_platform_driver(rn5t618_wdt_driver); |
192 | |
193 | MODULE_ALIAS("platform:rn5t618-wdt" ); |
194 | MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>" ); |
195 | MODULE_DESCRIPTION("RN5T618 watchdog driver" ); |
196 | MODULE_LICENSE("GPL v2" ); |
197 | |