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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 | 48 | /* |
c4718308 SR |
49 | * Read the currently active timeout. |
50 | * Zero means the watchdog is disabled. | |
be9e9c2a | 51 | */ |
c4718308 | 52 | static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063) |
be9e9c2a MF |
53 | { |
54 | unsigned int val; | |
55 | ||
56 | regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val); | |
57 | ||
c4718308 | 58 | return wdt_timeout[val & DA9063_TWDSCALE_MASK]; |
be9e9c2a MF |
59 | } |
60 | ||
e46bb55d MF |
61 | static int da9063_wdt_disable_timer(struct da9063 *da9063) |
62 | { | |
63 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, | |
64 | DA9063_TWDSCALE_MASK, | |
65 | DA9063_TWDSCALE_DISABLE); | |
66 | } | |
67 | ||
16a7eec2 MF |
68 | static int |
69 | da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout) | |
5e9c16e3 | 70 | { |
16a7eec2 | 71 | unsigned int regval; |
e46bb55d MF |
72 | int ret; |
73 | ||
74 | /* | |
75 | * The watchdog triggers a reboot if a timeout value is already | |
76 | * programmed because the timeout value combines two functions | |
77 | * in one: indicating the counter limit and starting the watchdog. | |
78 | * The watchdog must be disabled to be able to change the timeout | |
79 | * value if the watchdog is already running. Then we can set the | |
80 | * new timeout value which enables the watchdog again. | |
81 | */ | |
82 | ret = da9063_wdt_disable_timer(da9063); | |
83 | if (ret) | |
84 | return ret; | |
85 | ||
86 | usleep_range(150, 300); | |
16a7eec2 | 87 | regval = da9063_wdt_timeout_to_sel(timeout); |
e46bb55d | 88 | |
5e9c16e3 KG |
89 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, |
90 | DA9063_TWDSCALE_MASK, regval); | |
91 | } | |
92 | ||
93 | static int da9063_wdt_start(struct watchdog_device *wdd) | |
94 | { | |
a1f2a820 | 95 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
5e9c16e3 KG |
96 | int ret; |
97 | ||
16a7eec2 | 98 | ret = da9063_wdt_update_timeout(da9063, wdd->timeout); |
5e9c16e3 | 99 | if (ret) |
a1f2a820 | 100 | dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n", |
5e9c16e3 KG |
101 | ret); |
102 | ||
103 | return ret; | |
104 | } | |
105 | ||
106 | static int da9063_wdt_stop(struct watchdog_device *wdd) | |
107 | { | |
a1f2a820 | 108 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
5e9c16e3 KG |
109 | int ret; |
110 | ||
e46bb55d | 111 | ret = da9063_wdt_disable_timer(da9063); |
5e9c16e3 | 112 | if (ret) |
a1f2a820 | 113 | dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n", |
5e9c16e3 KG |
114 | ret); |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
119 | static int da9063_wdt_ping(struct watchdog_device *wdd) | |
120 | { | |
a1f2a820 | 121 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
5e9c16e3 KG |
122 | int ret; |
123 | ||
a1f2a820 | 124 | ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, |
5e9c16e3 KG |
125 | DA9063_WATCHDOG); |
126 | if (ret) | |
a1f2a820 | 127 | dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n", |
5e9c16e3 KG |
128 | ret); |
129 | ||
130 | return ret; | |
131 | } | |
132 | ||
133 | static int da9063_wdt_set_timeout(struct watchdog_device *wdd, | |
134 | unsigned int timeout) | |
135 | { | |
a1f2a820 | 136 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
44ee54aa | 137 | int ret = 0; |
5e9c16e3 | 138 | |
44ee54aa MF |
139 | /* |
140 | * There are two cases when a set_timeout() will be called: | |
141 | * 1. The watchdog is off and someone wants to set the timeout for the | |
142 | * further use. | |
143 | * 2. The watchdog is already running and a new timeout value should be | |
144 | * set. | |
145 | * | |
146 | * The watchdog can't store a timeout value not equal zero without | |
147 | * enabling the watchdog, so the timeout must be buffered by the driver. | |
148 | */ | |
149 | if (watchdog_active(wdd)) | |
16a7eec2 | 150 | ret = da9063_wdt_update_timeout(da9063, timeout); |
44ee54aa | 151 | |
5e9c16e3 | 152 | if (ret) |
a1f2a820 | 153 | dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", |
5e9c16e3 KG |
154 | ret); |
155 | else | |
16a7eec2 | 156 | wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)]; |
5e9c16e3 KG |
157 | |
158 | return ret; | |
159 | } | |
160 | ||
4d8b229d GR |
161 | static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, |
162 | void *data) | |
396f163c | 163 | { |
a1f2a820 | 164 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); |
396f163c GU |
165 | int ret; |
166 | ||
a1f2a820 | 167 | ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, |
396f163c GU |
168 | DA9063_SHUTDOWN); |
169 | if (ret) | |
a1f2a820 | 170 | dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n", |
396f163c GU |
171 | ret); |
172 | ||
f79781ce | 173 | return ret; |
396f163c GU |
174 | } |
175 | ||
5e9c16e3 KG |
176 | static const struct watchdog_info da9063_watchdog_info = { |
177 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
178 | .identity = "DA9063 Watchdog", | |
179 | }; | |
180 | ||
181 | static const struct watchdog_ops da9063_watchdog_ops = { | |
182 | .owner = THIS_MODULE, | |
183 | .start = da9063_wdt_start, | |
184 | .stop = da9063_wdt_stop, | |
185 | .ping = da9063_wdt_ping, | |
186 | .set_timeout = da9063_wdt_set_timeout, | |
f79781ce | 187 | .restart = da9063_wdt_restart, |
5e9c16e3 KG |
188 | }; |
189 | ||
190 | static int da9063_wdt_probe(struct platform_device *pdev) | |
191 | { | |
86580291 | 192 | struct device *dev = &pdev->dev; |
5e9c16e3 | 193 | struct da9063 *da9063; |
a1f2a820 | 194 | struct watchdog_device *wdd; |
c4718308 | 195 | unsigned int timeout; |
5e9c16e3 | 196 | |
86580291 | 197 | if (!dev->parent) |
5e9c16e3 KG |
198 | return -EINVAL; |
199 | ||
86580291 | 200 | da9063 = dev_get_drvdata(dev->parent); |
5e9c16e3 KG |
201 | if (!da9063) |
202 | return -EINVAL; | |
203 | ||
86580291 | 204 | wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); |
a1f2a820 | 205 | if (!wdd) |
5e9c16e3 KG |
206 | return -ENOMEM; |
207 | ||
a1f2a820 | 208 | wdd->info = &da9063_watchdog_info; |
209 | wdd->ops = &da9063_watchdog_ops; | |
210 | wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT; | |
211 | wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT; | |
212 | wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; | |
86580291 | 213 | wdd->parent = dev; |
a1f2a820 | 214 | wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS; |
5e9c16e3 | 215 | |
a1f2a820 | 216 | watchdog_set_restart_priority(wdd, 128); |
a1f2a820 | 217 | watchdog_set_drvdata(wdd, da9063); |
5e9c16e3 | 218 | |
280ce5c0 | 219 | wdd->timeout = DA9063_WDG_TIMEOUT; |
c4718308 SR |
220 | |
221 | /* Use pre-configured timeout if watchdog is already running. */ | |
222 | timeout = da9063_wdt_read_timeout(da9063); | |
223 | if (timeout) | |
224 | wdd->timeout = timeout; | |
225 | ||
226 | /* Set timeout, maybe override it with DT value, scale it */ | |
280ce5c0 WS |
227 | watchdog_init_timeout(wdd, 0, dev); |
228 | da9063_wdt_set_timeout(wdd, wdd->timeout); | |
229 | ||
c4718308 SR |
230 | /* Update timeout if the watchdog is already running. */ |
231 | if (timeout) { | |
280ce5c0 | 232 | da9063_wdt_update_timeout(da9063, wdd->timeout); |
be9e9c2a MF |
233 | set_bit(WDOG_HW_RUNNING, &wdd->status); |
234 | } | |
235 | ||
86580291 | 236 | return devm_watchdog_register_device(dev, wdd); |
5e9c16e3 KG |
237 | } |
238 | ||
239 | static struct platform_driver da9063_wdt_driver = { | |
240 | .probe = da9063_wdt_probe, | |
5e9c16e3 KG |
241 | .driver = { |
242 | .name = DA9063_DRVNAME_WATCHDOG, | |
243 | }, | |
244 | }; | |
245 | module_platform_driver(da9063_wdt_driver); | |
246 | ||
247 | MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); | |
248 | MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); | |
249 | MODULE_LICENSE("GPL"); | |
250 | MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); |