2 * Watchdog device driver for DA9062 and DA9061 PMICs
3 * Copyright (C) 2015 Dialog Semiconductor Ltd.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/watchdog.h>
19 #include <linux/platform_device.h>
20 #include <linux/uaccess.h>
21 #include <linux/slab.h>
22 #include <linux/delay.h>
23 #include <linux/jiffies.h>
24 #include <linux/mfd/da9062/registers.h>
25 #include <linux/mfd/da9062/core.h>
26 #include <linux/regmap.h>
29 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
30 #define DA9062_TWDSCALE_DISABLE 0
31 #define DA9062_TWDSCALE_MIN 1
32 #define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
33 #define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
34 #define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
35 #define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
36 #define DA9062_RESET_PROTECTION_MS 300
38 struct da9062_watchdog {
40 struct watchdog_device wdtdev;
41 unsigned long j_time_stamp;
44 static void da9062_set_window_start(struct da9062_watchdog *wdt)
46 wdt->j_time_stamp = jiffies;
49 static void da9062_apply_window_protection(struct da9062_watchdog *wdt)
51 unsigned long delay = msecs_to_jiffies(DA9062_RESET_PROTECTION_MS);
52 unsigned long timeout = wdt->j_time_stamp + delay;
53 unsigned long now = jiffies;
56 /* if time-limit has not elapsed then wait for remainder */
57 if (time_before(now, timeout)) {
58 diff_ms = jiffies_to_msecs(timeout-now);
60 "Kicked too quickly. Delaying %u msecs\n", diff_ms);
65 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
69 for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
70 if (wdt_timeout[i] >= secs)
74 return DA9062_TWDSCALE_MAX;
77 static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
81 da9062_apply_window_protection(wdt);
83 ret = regmap_update_bits(wdt->hw->regmap,
85 DA9062AA_WATCHDOG_MASK,
86 DA9062AA_WATCHDOG_MASK);
88 da9062_set_window_start(wdt);
93 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
96 struct da9062 *chip = wdt->hw;
98 return regmap_update_bits(chip->regmap,
100 DA9062AA_TWDSCALE_MASK,
104 static int da9062_wdt_start(struct watchdog_device *wdd)
106 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
107 unsigned int selector;
110 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
111 ret = da9062_wdt_update_timeout_register(wdt, selector);
113 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
119 static int da9062_wdt_stop(struct watchdog_device *wdd)
121 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
124 ret = regmap_update_bits(wdt->hw->regmap,
126 DA9062AA_TWDSCALE_MASK,
127 DA9062_TWDSCALE_DISABLE);
129 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
135 static int da9062_wdt_ping(struct watchdog_device *wdd)
137 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
140 ret = da9062_reset_watchdog_timer(wdt);
142 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
148 static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
149 unsigned int timeout)
151 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
152 unsigned int selector;
155 selector = da9062_wdt_timeout_to_sel(timeout);
156 ret = da9062_wdt_update_timeout_register(wdt, selector);
158 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
161 wdd->timeout = wdt_timeout[selector];
166 static const struct watchdog_info da9062_watchdog_info = {
167 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
168 .identity = "DA9062 WDT",
171 static const struct watchdog_ops da9062_watchdog_ops = {
172 .owner = THIS_MODULE,
173 .start = da9062_wdt_start,
174 .stop = da9062_wdt_stop,
175 .ping = da9062_wdt_ping,
176 .set_timeout = da9062_wdt_set_timeout,
179 static const struct of_device_id da9062_compatible_id_table[] = {
180 { .compatible = "dlg,da9062-watchdog", },
184 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
186 static int da9062_wdt_probe(struct platform_device *pdev)
190 struct da9062_watchdog *wdt;
192 chip = dev_get_drvdata(pdev->dev.parent);
196 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
202 wdt->wdtdev.info = &da9062_watchdog_info;
203 wdt->wdtdev.ops = &da9062_watchdog_ops;
204 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
205 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
206 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
207 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
208 wdt->wdtdev.parent = &pdev->dev;
210 watchdog_set_drvdata(&wdt->wdtdev, wdt);
212 ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
214 dev_err(wdt->hw->dev,
215 "watchdog registration failed (%d)\n", ret);
219 da9062_set_window_start(wdt);
221 return da9062_wdt_ping(&wdt->wdtdev);
224 static struct platform_driver da9062_wdt_driver = {
225 .probe = da9062_wdt_probe,
227 .name = "da9062-watchdog",
228 .of_match_table = da9062_compatible_id_table,
231 module_platform_driver(da9062_wdt_driver);
233 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
234 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
235 MODULE_LICENSE("GPL");
236 MODULE_ALIAS("platform:da9062-watchdog");