tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Watchdog device driver for DA9062 and DA9061 PMICs
4 * Copyright (C) 2015 Dialog Semiconductor Ltd.
5 *
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/watchdog.h>
11#include <linux/platform_device.h>
12#include <linux/uaccess.h>
13#include <linux/slab.h>
14#include <linux/i2c.h>
15#include <linux/delay.h>
16#include <linux/jiffies.h>
17#include <linux/mfd/da9062/registers.h>
18#include <linux/mfd/da9062/core.h>
19#include <linux/regmap.h>
20#include <linux/of.h>
21
22static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
23#define DA9062_TWDSCALE_DISABLE 0
24#define DA9062_TWDSCALE_MIN 1
25#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
26#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
27#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
28#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
29#define DA9062_RESET_PROTECTION_MS 300
30
31struct da9062_watchdog {
32 struct da9062 *hw;
33 struct watchdog_device wdtdev;
34};
35
36static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
37{
38 unsigned int i;
39
40 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
41 if (wdt_timeout[i] >= secs)
42 return i;
43 }
44
45 return DA9062_TWDSCALE_MAX;
46}
47
48static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
49{
50 return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
51 DA9062AA_WATCHDOG_MASK,
52 DA9062AA_WATCHDOG_MASK);
53}
54
55static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
56 unsigned int regval)
57{
58 struct da9062 *chip = wdt->hw;
59 int ret;
60
61 ret = da9062_reset_watchdog_timer(wdt);
62 if (ret)
63 return ret;
64
65 regmap_update_bits(chip->regmap,
66 DA9062AA_CONTROL_D,
67 DA9062AA_TWDSCALE_MASK,
68 DA9062_TWDSCALE_DISABLE);
69
70 usleep_range(150, 300);
71
72 return regmap_update_bits(chip->regmap,
73 DA9062AA_CONTROL_D,
74 DA9062AA_TWDSCALE_MASK,
75 regval);
76}
77
78static int da9062_wdt_start(struct watchdog_device *wdd)
79{
80 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
81 unsigned int selector;
82 int ret;
83
84 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
85 ret = da9062_wdt_update_timeout_register(wdt, selector);
86 if (ret)
87 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
88 ret);
89
90 return ret;
91}
92
93static int da9062_wdt_stop(struct watchdog_device *wdd)
94{
95 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
96 int ret;
97
98 ret = da9062_reset_watchdog_timer(wdt);
99 if (ret) {
100 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
101 ret);
102 return ret;
103 }
104
105 ret = regmap_update_bits(wdt->hw->regmap,
106 DA9062AA_CONTROL_D,
107 DA9062AA_TWDSCALE_MASK,
108 DA9062_TWDSCALE_DISABLE);
109 if (ret)
110 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
111 ret);
112
113 return ret;
114}
115
116static int da9062_wdt_ping(struct watchdog_device *wdd)
117{
118 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
119 int ret;
120
121 ret = da9062_reset_watchdog_timer(wdt);
122 if (ret)
123 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
124 ret);
125
126 return ret;
127}
128
129static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
130 unsigned int timeout)
131{
132 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
133 unsigned int selector;
134 int ret;
135
136 selector = da9062_wdt_timeout_to_sel(timeout);
137 ret = da9062_wdt_update_timeout_register(wdt, selector);
138 if (ret)
139 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
140 ret);
141 else
142 wdd->timeout = wdt_timeout[selector];
143
144 return ret;
145}
146
147static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
148 void *data)
149{
150 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
151 struct i2c_client *client = to_i2c_client(wdt->hw->dev);
152 int ret;
153
154 /* Don't use regmap because it is not atomic safe */
155 ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
156 DA9062AA_SHUTDOWN_MASK);
157 if (ret < 0)
158 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
159 ret);
160
161 /* wait for reset to assert... */
162 mdelay(500);
163
164 return ret;
165}
166
167static const struct watchdog_info da9062_watchdog_info = {
168 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
169 .identity = "DA9062 WDT",
170};
171
172static const struct watchdog_ops da9062_watchdog_ops = {
173 .owner = THIS_MODULE,
174 .start = da9062_wdt_start,
175 .stop = da9062_wdt_stop,
176 .ping = da9062_wdt_ping,
177 .set_timeout = da9062_wdt_set_timeout,
178 .restart = da9062_wdt_restart,
179};
180
181static const struct of_device_id da9062_compatible_id_table[] = {
182 { .compatible = "dlg,da9062-watchdog", },
183 { },
184};
185
186MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
187
188static int da9062_wdt_probe(struct platform_device *pdev)
189{
190 struct device *dev = &pdev->dev;
191 int ret;
192 struct da9062 *chip;
193 struct da9062_watchdog *wdt;
194
195 chip = dev_get_drvdata(dev->parent);
196 if (!chip)
197 return -EINVAL;
198
199 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
200 if (!wdt)
201 return -ENOMEM;
202
203 wdt->hw = chip;
204
205 wdt->wdtdev.info = &da9062_watchdog_info;
206 wdt->wdtdev.ops = &da9062_watchdog_ops;
207 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
208 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
209 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
210 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
211 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
212 wdt->wdtdev.parent = dev;
213
214 watchdog_set_restart_priority(&wdt->wdtdev, 128);
215
216 watchdog_set_drvdata(&wdt->wdtdev, wdt);
217 dev_set_drvdata(dev, &wdt->wdtdev);
218
219 ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
220 if (ret < 0)
221 return ret;
222
223 return da9062_wdt_ping(&wdt->wdtdev);
224}
225
226static int __maybe_unused da9062_wdt_suspend(struct device *dev)
227{
228 struct watchdog_device *wdd = dev_get_drvdata(dev);
229
230 if (watchdog_active(wdd))
231 return da9062_wdt_stop(wdd);
232
233 return 0;
234}
235
236static int __maybe_unused da9062_wdt_resume(struct device *dev)
237{
238 struct watchdog_device *wdd = dev_get_drvdata(dev);
239
240 if (watchdog_active(wdd))
241 return da9062_wdt_start(wdd);
242
243 return 0;
244}
245
246static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
247 da9062_wdt_suspend, da9062_wdt_resume);
248
249static struct platform_driver da9062_wdt_driver = {
250 .probe = da9062_wdt_probe,
251 .driver = {
252 .name = "da9062-watchdog",
253 .pm = &da9062_wdt_pm_ops,
254 .of_match_table = da9062_compatible_id_table,
255 },
256};
257module_platform_driver(da9062_wdt_driver);
258
259MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
260MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
261MODULE_LICENSE("GPL");
262MODULE_ALIAS("platform:da9062-watchdog");