1 | // SPDX-License-Identifier: GPL-2.0+ |
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 | * |
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> |
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; |
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 | |
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(wdd: 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, reg_val: 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 | reg_val: 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 | |
98 | static int da9052_wdt_start(struct watchdog_device *wdt_dev) |
99 | { |
100 | return da9052_wdt_set_timeout(wdt_dev, timeout: 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, timeout: 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(wdd: 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, reg_val: 1 << 7); |
126 | if (ret < 0) |
127 | return ret; |
128 | |
129 | /* |
130 | * FIXME: Reset the watchdog core, in general PMIC |
131 | * is supposed to do this |
132 | */ |
133 | return da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
134 | DA9052_CONTROLD_WATCHDOG, reg_val: 0 << 7); |
135 | } |
136 | |
137 | static const struct watchdog_info da9052_wdt_info = { |
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, |
148 | }; |
149 | |
150 | |
151 | static int da9052_wdt_probe(struct platform_device *pdev) |
152 | { |
153 | struct device *dev = &pdev->dev; |
154 | struct da9052 *da9052 = dev_get_drvdata(dev: dev->parent); |
155 | struct da9052_wdt_data *driver_data; |
156 | struct watchdog_device *da9052_wdt; |
157 | int ret; |
158 | |
159 | driver_data = devm_kzalloc(dev, size: sizeof(*driver_data), GFP_KERNEL); |
160 | if (!driver_data) |
161 | return -ENOMEM; |
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; |
169 | da9052_wdt->parent = dev; |
170 | watchdog_set_drvdata(wdd: da9052_wdt, data: driver_data); |
171 | |
172 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
173 | DA9052_CONTROLD_TWDSCALE, reg_val: 0); |
174 | if (ret < 0) { |
175 | dev_err(dev, "Failed to disable watchdog bits, %d\n" , ret); |
176 | return ret; |
177 | } |
178 | |
179 | return devm_watchdog_register_device(dev, &driver_data->wdt); |
180 | } |
181 | |
182 | static struct platform_driver da9052_wdt_driver = { |
183 | .probe = da9052_wdt_probe, |
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" ); |
195 | |