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2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
312b00e1 AJ |
2 | /* |
3 | * System monitoring driver for DA9055 PMICs. | |
4 | * | |
5 | * Copyright(c) 2012 Dialog Semiconductor Ltd. | |
6 | * | |
7 | * Author: David Dajun Chen <dchen@diasemi.com> | |
8 | * | |
312b00e1 AJ |
9 | */ |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/watchdog.h> | |
17 | #include <linux/delay.h> | |
18 | ||
19 | #include <linux/mfd/da9055/core.h> | |
20 | #include <linux/mfd/da9055/reg.h> | |
21 | ||
22 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
23 | module_param(nowayout, bool, 0); | |
24 | MODULE_PARM_DESC(nowayout, | |
25 | "Watchdog cannot be stopped once started (default=" | |
26 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
27 | ||
28 | #define DA9055_DEF_TIMEOUT 4 | |
29 | #define DA9055_TWDMIN 256 | |
30 | ||
31 | struct da9055_wdt_data { | |
32 | struct watchdog_device wdt; | |
33 | struct da9055 *da9055; | |
312b00e1 AJ |
34 | }; |
35 | ||
36 | static const struct { | |
37 | u8 reg_val; | |
38 | int user_time; /* In seconds */ | |
39 | } da9055_wdt_maps[] = { | |
40 | { 0, 0 }, | |
41 | { 1, 2 }, | |
42 | { 2, 4 }, | |
43 | { 3, 8 }, | |
44 | { 4, 16 }, | |
45 | { 5, 32 }, | |
46 | { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ | |
47 | { 6, 65 }, | |
48 | { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ | |
49 | { 7, 131 }, | |
50 | }; | |
51 | ||
52 | static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
53 | unsigned int timeout) | |
54 | { | |
55 | struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
56 | struct da9055 *da9055 = driver_data->da9055; | |
57 | int ret, i; | |
58 | ||
59 | for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++) | |
60 | if (da9055_wdt_maps[i].user_time == timeout) | |
61 | break; | |
62 | ||
63 | if (i == ARRAY_SIZE(da9055_wdt_maps)) | |
64 | ret = -EINVAL; | |
65 | else | |
66 | ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B, | |
67 | DA9055_TWDSCALE_MASK, | |
68 | da9055_wdt_maps[i].reg_val << | |
69 | DA9055_TWDSCALE_SHIFT); | |
98e4a293 | 70 | if (ret < 0) { |
312b00e1 AJ |
71 | dev_err(da9055->dev, |
72 | "Failed to update timescale bit, %d\n", ret); | |
98e4a293 AL |
73 | return ret; |
74 | } | |
312b00e1 AJ |
75 | |
76 | wdt_dev->timeout = timeout; | |
77 | ||
98e4a293 | 78 | return 0; |
312b00e1 AJ |
79 | } |
80 | ||
81 | static int da9055_wdt_ping(struct watchdog_device *wdt_dev) | |
82 | { | |
83 | struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
84 | struct da9055 *da9055 = driver_data->da9055; | |
312b00e1 AJ |
85 | |
86 | /* | |
87 | * We have a minimum time for watchdog window called TWDMIN. A write | |
88 | * to the watchdog before this elapsed time will cause an error. | |
89 | */ | |
90 | mdelay(DA9055_TWDMIN); | |
91 | ||
92 | /* Reset the watchdog timer */ | |
98e4a293 AL |
93 | return da9055_reg_update(da9055, DA9055_REG_CONTROL_E, |
94 | DA9055_WATCHDOG_MASK, 1); | |
312b00e1 AJ |
95 | } |
96 | ||
312b00e1 AJ |
97 | static int da9055_wdt_start(struct watchdog_device *wdt_dev) |
98 | { | |
99 | return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
100 | } | |
101 | ||
102 | static int da9055_wdt_stop(struct watchdog_device *wdt_dev) | |
103 | { | |
104 | return da9055_wdt_set_timeout(wdt_dev, 0); | |
105 | } | |
106 | ||
6c368932 | 107 | static const struct watchdog_info da9055_wdt_info = { |
312b00e1 AJ |
108 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
109 | .identity = "DA9055 Watchdog", | |
110 | }; | |
111 | ||
112 | static const struct watchdog_ops da9055_wdt_ops = { | |
113 | .owner = THIS_MODULE, | |
114 | .start = da9055_wdt_start, | |
115 | .stop = da9055_wdt_stop, | |
116 | .ping = da9055_wdt_ping, | |
117 | .set_timeout = da9055_wdt_set_timeout, | |
312b00e1 AJ |
118 | }; |
119 | ||
120 | static int da9055_wdt_probe(struct platform_device *pdev) | |
121 | { | |
862c13b5 GR |
122 | struct device *dev = &pdev->dev; |
123 | struct da9055 *da9055 = dev_get_drvdata(dev->parent); | |
312b00e1 AJ |
124 | struct da9055_wdt_data *driver_data; |
125 | struct watchdog_device *da9055_wdt; | |
126 | int ret; | |
127 | ||
862c13b5 | 128 | driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL); |
8deea830 | 129 | if (!driver_data) |
312b00e1 | 130 | return -ENOMEM; |
312b00e1 AJ |
131 | |
132 | driver_data->da9055 = da9055; | |
133 | ||
134 | da9055_wdt = &driver_data->wdt; | |
135 | ||
136 | da9055_wdt->timeout = DA9055_DEF_TIMEOUT; | |
137 | da9055_wdt->info = &da9055_wdt_info; | |
138 | da9055_wdt->ops = &da9055_wdt_ops; | |
862c13b5 | 139 | da9055_wdt->parent = dev; |
312b00e1 AJ |
140 | watchdog_set_nowayout(da9055_wdt, nowayout); |
141 | watchdog_set_drvdata(da9055_wdt, driver_data); | |
142 | ||
312b00e1 AJ |
143 | ret = da9055_wdt_stop(da9055_wdt); |
144 | if (ret < 0) { | |
862c13b5 | 145 | dev_err(dev, "Failed to stop watchdog, %d\n", ret); |
89f944c0 | 146 | return ret; |
312b00e1 AJ |
147 | } |
148 | ||
862c13b5 | 149 | ret = devm_watchdog_register_device(dev, &driver_data->wdt); |
312b00e1 AJ |
150 | if (ret != 0) |
151 | dev_err(da9055->dev, "watchdog_register_device() failed: %d\n", | |
152 | ret); | |
153 | ||
312b00e1 AJ |
154 | return ret; |
155 | } | |
156 | ||
312b00e1 AJ |
157 | static struct platform_driver da9055_wdt_driver = { |
158 | .probe = da9055_wdt_probe, | |
312b00e1 AJ |
159 | .driver = { |
160 | .name = "da9055-watchdog", | |
161 | }, | |
162 | }; | |
163 | ||
164 | module_platform_driver(da9055_wdt_driver); | |
165 | ||
166 | MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>"); | |
167 | MODULE_DESCRIPTION("DA9055 watchdog"); | |
168 | MODULE_LICENSE("GPL"); | |
169 | MODULE_ALIAS("platform:da9055-watchdog"); |