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2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
664a0d78 AJ |
2 | /* |
3 | * System monitoring driver for DA9052 PMICs. | |
4 | * | |
5 | * Copyright(c) 2012 Dialog Semiconductor Ltd. | |
6 | * | |
7 | * Author: Anthony Olech <Anthony.Olech@diasemi.com> | |
8 | * | |
664a0d78 AJ |
9 | */ |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/delay.h> | |
13 | #include <linux/uaccess.h> | |
14 | #include <linux/platform_device.h> | |
15 | #include <linux/time.h> | |
16 | #include <linux/watchdog.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/jiffies.h> | |
664a0d78 AJ |
20 | |
21 | #include <linux/mfd/da9052/reg.h> | |
22 | #include <linux/mfd/da9052/da9052.h> | |
23 | ||
24 | #define DA9052_DEF_TIMEOUT 4 | |
25 | #define DA9052_TWDMIN 256 | |
26 | ||
27 | struct da9052_wdt_data { | |
28 | struct watchdog_device wdt; | |
29 | struct da9052 *da9052; | |
664a0d78 AJ |
30 | unsigned long jpast; |
31 | }; | |
32 | ||
33 | static const struct { | |
34 | u8 reg_val; | |
35 | int time; /* Seconds */ | |
36 | } da9052_wdt_maps[] = { | |
37 | { 1, 2 }, | |
38 | { 2, 4 }, | |
39 | { 3, 8 }, | |
40 | { 4, 16 }, | |
41 | { 5, 32 }, | |
42 | { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ | |
43 | { 6, 65 }, | |
44 | { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ | |
45 | { 7, 131 }, | |
46 | }; | |
47 | ||
48 | ||
664a0d78 AJ |
49 | static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev, |
50 | unsigned int timeout) | |
51 | { | |
52 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
53 | struct da9052 *da9052 = driver_data->da9052; | |
54 | int ret, i; | |
55 | ||
56 | /* | |
57 | * Disable the Watchdog timer before setting | |
58 | * new time out. | |
59 | */ | |
60 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
61 | DA9052_CONTROLD_TWDSCALE, 0); | |
62 | if (ret < 0) { | |
63 | dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", | |
64 | ret); | |
65 | return ret; | |
66 | } | |
67 | if (timeout) { | |
68 | /* | |
69 | * To change the timeout, da9052 needs to | |
70 | * be disabled for at least 150 us. | |
71 | */ | |
72 | udelay(150); | |
73 | ||
74 | /* Set the desired timeout */ | |
75 | for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) | |
76 | if (da9052_wdt_maps[i].time == timeout) | |
77 | break; | |
78 | ||
79 | if (i == ARRAY_SIZE(da9052_wdt_maps)) | |
80 | ret = -EINVAL; | |
81 | else | |
82 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
83 | DA9052_CONTROLD_TWDSCALE, | |
84 | da9052_wdt_maps[i].reg_val); | |
85 | if (ret < 0) { | |
86 | dev_err(da9052->dev, | |
87 | "Failed to update timescale bit, %d\n", ret); | |
88 | return ret; | |
89 | } | |
90 | ||
91 | wdt_dev->timeout = timeout; | |
92 | driver_data->jpast = jiffies; | |
93 | } | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
664a0d78 AJ |
98 | static int da9052_wdt_start(struct watchdog_device *wdt_dev) |
99 | { | |
100 | return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
101 | } | |
102 | ||
103 | static int da9052_wdt_stop(struct watchdog_device *wdt_dev) | |
104 | { | |
105 | return da9052_wdt_set_timeout(wdt_dev, 0); | |
106 | } | |
107 | ||
108 | static int da9052_wdt_ping(struct watchdog_device *wdt_dev) | |
109 | { | |
110 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
111 | struct da9052 *da9052 = driver_data->da9052; | |
112 | unsigned long msec, jnow = jiffies; | |
113 | int ret; | |
114 | ||
115 | /* | |
116 | * We have a minimum time for watchdog window called TWDMIN. A write | |
117 | * to the watchdog before this elapsed time should cause an error. | |
118 | */ | |
119 | msec = (jnow - driver_data->jpast) * 1000/HZ; | |
120 | if (msec < DA9052_TWDMIN) | |
121 | mdelay(msec); | |
122 | ||
123 | /* Reset the watchdog timer */ | |
124 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
125 | DA9052_CONTROLD_WATCHDOG, 1 << 7); | |
126 | if (ret < 0) | |
189c049a | 127 | return ret; |
664a0d78 AJ |
128 | |
129 | /* | |
130 | * FIXME: Reset the watchdog core, in general PMIC | |
131 | * is supposed to do this | |
132 | */ | |
189c049a GR |
133 | return da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
134 | DA9052_CONTROLD_WATCHDOG, 0 << 7); | |
664a0d78 AJ |
135 | } |
136 | ||
6c368932 | 137 | static const struct watchdog_info da9052_wdt_info = { |
664a0d78 AJ |
138 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
139 | .identity = "DA9052 Watchdog", | |
140 | }; | |
141 | ||
142 | static const struct watchdog_ops da9052_wdt_ops = { | |
143 | .owner = THIS_MODULE, | |
144 | .start = da9052_wdt_start, | |
145 | .stop = da9052_wdt_stop, | |
146 | .ping = da9052_wdt_ping, | |
147 | .set_timeout = da9052_wdt_set_timeout, | |
664a0d78 AJ |
148 | }; |
149 | ||
150 | ||
2d991a16 | 151 | static int da9052_wdt_probe(struct platform_device *pdev) |
664a0d78 | 152 | { |
f7e29623 GR |
153 | struct device *dev = &pdev->dev; |
154 | struct da9052 *da9052 = dev_get_drvdata(dev->parent); | |
664a0d78 AJ |
155 | struct da9052_wdt_data *driver_data; |
156 | struct watchdog_device *da9052_wdt; | |
157 | int ret; | |
158 | ||
f7e29623 | 159 | driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL); |
189c049a GR |
160 | if (!driver_data) |
161 | return -ENOMEM; | |
664a0d78 AJ |
162 | driver_data->da9052 = da9052; |
163 | ||
164 | da9052_wdt = &driver_data->wdt; | |
165 | ||
166 | da9052_wdt->timeout = DA9052_DEF_TIMEOUT; | |
167 | da9052_wdt->info = &da9052_wdt_info; | |
168 | da9052_wdt->ops = &da9052_wdt_ops; | |
f7e29623 | 169 | da9052_wdt->parent = dev; |
664a0d78 AJ |
170 | watchdog_set_drvdata(da9052_wdt, driver_data); |
171 | ||
664a0d78 AJ |
172 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
173 | DA9052_CONTROLD_TWDSCALE, 0); | |
174 | if (ret < 0) { | |
f7e29623 | 175 | dev_err(dev, "Failed to disable watchdog bits, %d\n", ret); |
189c049a | 176 | return ret; |
664a0d78 AJ |
177 | } |
178 | ||
60415f70 | 179 | return devm_watchdog_register_device(dev, &driver_data->wdt); |
664a0d78 AJ |
180 | } |
181 | ||
664a0d78 AJ |
182 | static struct platform_driver da9052_wdt_driver = { |
183 | .probe = da9052_wdt_probe, | |
664a0d78 AJ |
184 | .driver = { |
185 | .name = "da9052-watchdog", | |
186 | }, | |
187 | }; | |
188 | ||
189 | module_platform_driver(da9052_wdt_driver); | |
190 | ||
191 | MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); | |
192 | MODULE_DESCRIPTION("DA9052 SM Device Driver"); | |
193 | MODULE_LICENSE("GPL"); | |
194 | MODULE_ALIAS("platform:da9052-watchdog"); |