Commit | Line | Data |
---|---|---|
2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
5e9c16e3 KG |
2 | /* |
3 | * Watchdog driver for DA9063 PMICs. | |
4 | * | |
5 | * Copyright(c) 2012 Dialog Semiconductor Ltd. | |
6 | * | |
7 | * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com> | |
8 | * | |
5e9c16e3 KG |
9 | */ |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/watchdog.h> | |
14 | #include <linux/platform_device.h> | |
15 | #include <linux/uaccess.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/mfd/da9063/registers.h> | |
19 | #include <linux/mfd/da9063/core.h> | |
20 | #include <linux/regmap.h> | |
21 | ||
22 | /* | |
23 | * Watchdog selector to timeout in seconds. | |
24 | * 0: WDT disabled; | |
25 | * others: timeout = 2048 ms * 2^(TWDSCALE-1). | |
26 | */ | |
27 | static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; | |
28 | #define DA9063_TWDSCALE_DISABLE 0 | |
29 | #define DA9063_TWDSCALE_MIN 1 | |
30 | #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) | |
31 | #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] | |
32 | #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] | |
33 | #define DA9063_WDG_TIMEOUT wdt_timeout[3] | |
a74cab40 | 34 | #define DA9063_RESET_PROTECTION_MS 256 |
5e9c16e3 | 35 | |
5e9c16e3 KG |
36 | static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) |
37 | { | |
38 | unsigned int i; | |
39 | ||
40 | for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { | |
41 | if (wdt_timeout[i] >= secs) | |
42 | return i; | |
43 | } | |
44 | ||
45 | return DA9063_TWDSCALE_MAX; | |
46 | } | |
47 | ||
be9e9c2a MF |
48 | /* |
49 | * Return 0 if watchdog is disabled, else non zero. | |
50 | */ | |
51 | static unsigned int da9063_wdt_is_running(struct da9063 *da9063) | |
52 | { | |
53 | unsigned int val; | |
54 | ||
55 | regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val); | |
56 | ||
57 | return val & DA9063_TWDSCALE_MASK; | |
58 | } | |
59 | ||
e46bb55d MF |
60 | static int da9063_wdt_disable_timer(struct da9063 *da9063) |
61 | { | |
62 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, | |
63 | DA9063_TWDSCALE_MASK, | |
64 | DA9063_TWDSCALE_DISABLE); | |
65 | } | |
66 | ||
16a7eec2 MF |
67 | static int |
68 | da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout) | |
5e9c16e3 | 69 | { |
16a7eec2 | 70 | unsigned int regval; |
e46bb55d MF |
71 | int ret; |
72 | ||
73 | /* | |
74 | * The watchdog triggers a reboot if a timeout value is already | |
75 | * programmed because the timeout value combines two functions | |
76 | * in one: indicating the counter limit and starting the watchdog. | |
77 | * The watchdog must be disabled to be able to change the timeout | |
78 | * value if the watchdog is already running. Then we can set the | |
79 | * new timeout value which enables the watchdog again. | |
80 | */ | |
81 | ret = da9063_wdt_disable_timer(da9063); | |
82 | if (ret) | |
83 | return ret; | |
84 | ||
85 | usleep_range(150, 300); | |
16a7eec2 | 86 | regval = da9063_wdt_timeout_to_sel(timeout); |
e46bb55d | 87 | |
5e9c16e3 KG |
88 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, |
89 | DA9063_TWDSCALE_MASK, regval); | |
90 | } | |
91 | ||
92 | static int da9063_wdt_start(struct watchdog_device *wdd) | |
93 | { | |
a1f2a820 | 94 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
5e9c16e3 KG |
95 | int ret; |
96 | ||
16a7eec2 | 97 | ret = da9063_wdt_update_timeout(da9063, wdd->timeout); |
5e9c16e3 | 98 | if (ret) |
a1f2a820 | 99 | dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n", |
5e9c16e3 KG |
100 | ret); |
101 | ||
102 | return ret; | |
103 | } | |
104 | ||
105 | static int da9063_wdt_stop(struct watchdog_device *wdd) | |
106 | { | |
a1f2a820 | 107 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
5e9c16e3 KG |
108 | int ret; |
109 | ||
e46bb55d | 110 | ret = da9063_wdt_disable_timer(da9063); |
5e9c16e3 | 111 | if (ret) |
a1f2a820 | 112 | dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n", |
5e9c16e3 KG |
113 | ret); |
114 | ||
115 | return ret; | |
116 | } | |
117 | ||
118 | static int da9063_wdt_ping(struct watchdog_device *wdd) | |
119 | { | |
a1f2a820 | 120 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
5e9c16e3 KG |
121 | int ret; |
122 | ||
a1f2a820 | 123 | ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, |
5e9c16e3 KG |
124 | DA9063_WATCHDOG); |
125 | if (ret) | |
a1f2a820 | 126 | dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n", |
5e9c16e3 KG |
127 | ret); |
128 | ||
129 | return ret; | |
130 | } | |
131 | ||
132 | static int da9063_wdt_set_timeout(struct watchdog_device *wdd, | |
133 | unsigned int timeout) | |
134 | { | |
a1f2a820 | 135 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
44ee54aa | 136 | int ret = 0; |
5e9c16e3 | 137 | |
44ee54aa MF |
138 | /* |
139 | * There are two cases when a set_timeout() will be called: | |
140 | * 1. The watchdog is off and someone wants to set the timeout for the | |
141 | * further use. | |
142 | * 2. The watchdog is already running and a new timeout value should be | |
143 | * set. | |
144 | * | |
145 | * The watchdog can't store a timeout value not equal zero without | |
146 | * enabling the watchdog, so the timeout must be buffered by the driver. | |
147 | */ | |
148 | if (watchdog_active(wdd)) | |
16a7eec2 | 149 | ret = da9063_wdt_update_timeout(da9063, timeout); |
44ee54aa | 150 | |
5e9c16e3 | 151 | if (ret) |
a1f2a820 | 152 | dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", |
5e9c16e3 KG |
153 | ret); |
154 | else | |
16a7eec2 | 155 | wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)]; |
5e9c16e3 KG |
156 | |
157 | return ret; | |
158 | } | |
159 | ||
4d8b229d GR |
160 | static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, |
161 | void *data) | |
396f163c | 162 | { |
a1f2a820 | 163 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
396f163c GU |
164 | int ret; |
165 | ||
a1f2a820 | 166 | ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, |
396f163c GU |
167 | DA9063_SHUTDOWN); |
168 | if (ret) | |
a1f2a820 | 169 | dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n", |
396f163c GU |
170 | ret); |
171 | ||
f79781ce | 172 | return ret; |
396f163c GU |
173 | } |
174 | ||
5e9c16e3 KG |
175 | static const struct watchdog_info da9063_watchdog_info = { |
176 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
177 | .identity = "DA9063 Watchdog", | |
178 | }; | |
179 | ||
180 | static const struct watchdog_ops da9063_watchdog_ops = { | |
181 | .owner = THIS_MODULE, | |
182 | .start = da9063_wdt_start, | |
183 | .stop = da9063_wdt_stop, | |
184 | .ping = da9063_wdt_ping, | |
185 | .set_timeout = da9063_wdt_set_timeout, | |
f79781ce | 186 | .restart = da9063_wdt_restart, |
5e9c16e3 KG |
187 | }; |
188 | ||
189 | static int da9063_wdt_probe(struct platform_device *pdev) | |
190 | { | |
86580291 | 191 | struct device *dev = &pdev->dev; |
5e9c16e3 | 192 | struct da9063 *da9063; |
a1f2a820 | 193 | struct watchdog_device *wdd; |
5e9c16e3 | 194 | |
86580291 | 195 | if (!dev->parent) |
5e9c16e3 KG |
196 | return -EINVAL; |
197 | ||
86580291 | 198 | da9063 = dev_get_drvdata(dev->parent); |
5e9c16e3 KG |
199 | if (!da9063) |
200 | return -EINVAL; | |
201 | ||
86580291 | 202 | wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); |
a1f2a820 | 203 | if (!wdd) |
5e9c16e3 KG |
204 | return -ENOMEM; |
205 | ||
a1f2a820 | 206 | wdd->info = &da9063_watchdog_info; |
207 | wdd->ops = &da9063_watchdog_ops; | |
208 | wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT; | |
209 | wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT; | |
210 | wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; | |
86580291 | 211 | wdd->parent = dev; |
a1f2a820 | 212 | wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS; |
5e9c16e3 | 213 | |
a1f2a820 | 214 | watchdog_set_restart_priority(wdd, 128); |
a1f2a820 | 215 | watchdog_set_drvdata(wdd, da9063); |
5e9c16e3 | 216 | |
280ce5c0 WS |
217 | /* Set default timeout, maybe override it with DT value, scale it */ |
218 | wdd->timeout = DA9063_WDG_TIMEOUT; | |
219 | watchdog_init_timeout(wdd, 0, dev); | |
220 | da9063_wdt_set_timeout(wdd, wdd->timeout); | |
221 | ||
be9e9c2a MF |
222 | /* Change the timeout to the default value if the watchdog is running */ |
223 | if (da9063_wdt_is_running(da9063)) { | |
280ce5c0 | 224 | da9063_wdt_update_timeout(da9063, wdd->timeout); |
be9e9c2a MF |
225 | set_bit(WDOG_HW_RUNNING, &wdd->status); |
226 | } | |
227 | ||
86580291 | 228 | return devm_watchdog_register_device(dev, wdd); |
5e9c16e3 KG |
229 | } |
230 | ||
231 | static struct platform_driver da9063_wdt_driver = { | |
232 | .probe = da9063_wdt_probe, | |
5e9c16e3 KG |
233 | .driver = { |
234 | .name = DA9063_DRVNAME_WATCHDOG, | |
235 | }, | |
236 | }; | |
237 | module_platform_driver(da9063_wdt_driver); | |
238 | ||
239 | MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); | |
240 | MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); | |
241 | MODULE_LICENSE("GPL"); | |
242 | MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); |