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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
27struct da9052_wdt_data {
28 struct watchdog_device wdt;
29 struct da9052 *da9052;
30 unsigned long jpast;
31};
32
33static 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
49static 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
98static int da9052_wdt_start(struct watchdog_device *wdt_dev)
99{
100 return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
101}
102
103static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
104{
105 return da9052_wdt_set_timeout(wdt_dev, 0);
106}
107
108static 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)
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, 0 << 7);
135}
136
137static const struct watchdog_info da9052_wdt_info = {
138 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
139 .identity = "DA9052 Watchdog",
140};
141
142static 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
151static int da9052_wdt_probe(struct platform_device *pdev)
152{
153 struct device *dev = &pdev->dev;
154 struct da9052 *da9052 = dev_get_drvdata(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, 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(da9052_wdt, driver_data);
171
172 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
173 DA9052_CONTROLD_TWDSCALE, 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
182static struct platform_driver da9052_wdt_driver = {
183 .probe = da9052_wdt_probe,
184 .driver = {
185 .name = "da9052-watchdog",
186 },
187};
188
189module_platform_driver(da9052_wdt_driver);
190
191MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
192MODULE_DESCRIPTION("DA9052 SM Device Driver");
193MODULE_LICENSE("GPL");
194MODULE_ALIAS("platform:da9052-watchdog");
1/*
2 * System monitoring driver for DA9052 PMICs.
3 *
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
5 *
6 * Author: Anthony Olech <Anthony.Olech@diasemi.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/delay.h>
17#include <linux/uaccess.h>
18#include <linux/platform_device.h>
19#include <linux/time.h>
20#include <linux/watchdog.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/jiffies.h>
24
25#include <linux/mfd/da9052/reg.h>
26#include <linux/mfd/da9052/da9052.h>
27
28#define DA9052_DEF_TIMEOUT 4
29#define DA9052_TWDMIN 256
30
31struct da9052_wdt_data {
32 struct watchdog_device wdt;
33 struct da9052 *da9052;
34 unsigned long jpast;
35};
36
37static const struct {
38 u8 reg_val;
39 int time; /* Seconds */
40} da9052_wdt_maps[] = {
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
53static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
54 unsigned int timeout)
55{
56 struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
57 struct da9052 *da9052 = driver_data->da9052;
58 int ret, i;
59
60 /*
61 * Disable the Watchdog timer before setting
62 * new time out.
63 */
64 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
65 DA9052_CONTROLD_TWDSCALE, 0);
66 if (ret < 0) {
67 dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
68 ret);
69 return ret;
70 }
71 if (timeout) {
72 /*
73 * To change the timeout, da9052 needs to
74 * be disabled for at least 150 us.
75 */
76 udelay(150);
77
78 /* Set the desired timeout */
79 for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
80 if (da9052_wdt_maps[i].time == timeout)
81 break;
82
83 if (i == ARRAY_SIZE(da9052_wdt_maps))
84 ret = -EINVAL;
85 else
86 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
87 DA9052_CONTROLD_TWDSCALE,
88 da9052_wdt_maps[i].reg_val);
89 if (ret < 0) {
90 dev_err(da9052->dev,
91 "Failed to update timescale bit, %d\n", ret);
92 return ret;
93 }
94
95 wdt_dev->timeout = timeout;
96 driver_data->jpast = jiffies;
97 }
98
99 return 0;
100}
101
102static int da9052_wdt_start(struct watchdog_device *wdt_dev)
103{
104 return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
105}
106
107static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
108{
109 return da9052_wdt_set_timeout(wdt_dev, 0);
110}
111
112static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
113{
114 struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
115 struct da9052 *da9052 = driver_data->da9052;
116 unsigned long msec, jnow = jiffies;
117 int ret;
118
119 /*
120 * We have a minimum time for watchdog window called TWDMIN. A write
121 * to the watchdog before this elapsed time should cause an error.
122 */
123 msec = (jnow - driver_data->jpast) * 1000/HZ;
124 if (msec < DA9052_TWDMIN)
125 mdelay(msec);
126
127 /* Reset the watchdog timer */
128 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
129 DA9052_CONTROLD_WATCHDOG, 1 << 7);
130 if (ret < 0)
131 goto err_strobe;
132
133 /*
134 * FIXME: Reset the watchdog core, in general PMIC
135 * is supposed to do this
136 */
137 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
138 DA9052_CONTROLD_WATCHDOG, 0 << 7);
139err_strobe:
140 return ret;
141}
142
143static struct watchdog_info da9052_wdt_info = {
144 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
145 .identity = "DA9052 Watchdog",
146};
147
148static const struct watchdog_ops da9052_wdt_ops = {
149 .owner = THIS_MODULE,
150 .start = da9052_wdt_start,
151 .stop = da9052_wdt_stop,
152 .ping = da9052_wdt_ping,
153 .set_timeout = da9052_wdt_set_timeout,
154};
155
156
157static int da9052_wdt_probe(struct platform_device *pdev)
158{
159 struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
160 struct da9052_wdt_data *driver_data;
161 struct watchdog_device *da9052_wdt;
162 int ret;
163
164 driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
165 GFP_KERNEL);
166 if (!driver_data) {
167 ret = -ENOMEM;
168 goto err;
169 }
170 driver_data->da9052 = da9052;
171
172 da9052_wdt = &driver_data->wdt;
173
174 da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
175 da9052_wdt->info = &da9052_wdt_info;
176 da9052_wdt->ops = &da9052_wdt_ops;
177 da9052_wdt->parent = &pdev->dev;
178 watchdog_set_drvdata(da9052_wdt, driver_data);
179
180 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
181 DA9052_CONTROLD_TWDSCALE, 0);
182 if (ret < 0) {
183 dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n",
184 ret);
185 goto err;
186 }
187
188 ret = watchdog_register_device(&driver_data->wdt);
189 if (ret != 0) {
190 dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
191 ret);
192 goto err;
193 }
194
195 platform_set_drvdata(pdev, driver_data);
196err:
197 return ret;
198}
199
200static int da9052_wdt_remove(struct platform_device *pdev)
201{
202 struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev);
203
204 watchdog_unregister_device(&driver_data->wdt);
205
206 return 0;
207}
208
209static struct platform_driver da9052_wdt_driver = {
210 .probe = da9052_wdt_probe,
211 .remove = da9052_wdt_remove,
212 .driver = {
213 .name = "da9052-watchdog",
214 },
215};
216
217module_platform_driver(da9052_wdt_driver);
218
219MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
220MODULE_DESCRIPTION("DA9052 SM Device Driver");
221MODULE_LICENSE("GPL");
222MODULE_ALIAS("platform:da9052-watchdog");