Merge tag 'trace-v5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
[linux/fpc-iii.git] / drivers / watchdog / uniphier_wdt.c
blob8e9242c2302222155094542461117d4f10068d0a
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Watchdog driver for the UniPhier watchdog timer
5 * (c) Copyright 2014 Panasonic Corporation
6 * (c) Copyright 2016 Socionext Inc.
7 * All rights reserved.
8 */
10 #include <linux/bitops.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 #include <linux/watchdog.h>
18 /* WDT timer setting register */
19 #define WDTTIMSET 0x3004
20 #define WDTTIMSET_PERIOD_MASK (0xf << 0)
21 #define WDTTIMSET_PERIOD_1_SEC (0x3 << 0)
23 /* WDT reset selection register */
24 #define WDTRSTSEL 0x3008
25 #define WDTRSTSEL_RSTSEL_MASK (0x3 << 0)
26 #define WDTRSTSEL_RSTSEL_BOTH (0x0 << 0)
27 #define WDTRSTSEL_RSTSEL_IRQ_ONLY (0x2 << 0)
29 /* WDT control register */
30 #define WDTCTRL 0x300c
31 #define WDTCTRL_STATUS BIT(8)
32 #define WDTCTRL_CLEAR BIT(1)
33 #define WDTCTRL_ENABLE BIT(0)
35 #define SEC_TO_WDTTIMSET_PRD(sec) \
36 (ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)
38 #define WDTST_TIMEOUT 1000 /* usec */
40 #define WDT_DEFAULT_TIMEOUT 64 /* Default is 64 seconds */
41 #define WDT_PERIOD_MIN 1
42 #define WDT_PERIOD_MAX 128
44 static unsigned int timeout = 0;
45 static bool nowayout = WATCHDOG_NOWAYOUT;
47 struct uniphier_wdt_dev {
48 struct watchdog_device wdt_dev;
49 struct regmap *regmap;
53 * UniPhier Watchdog operations
55 static int uniphier_watchdog_ping(struct watchdog_device *w)
57 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
58 unsigned int val;
59 int ret;
61 /* Clear counter */
62 ret = regmap_write_bits(wdev->regmap, WDTCTRL,
63 WDTCTRL_CLEAR, WDTCTRL_CLEAR);
64 if (!ret)
66 * As SoC specification, after clear counter,
67 * it needs to wait until counter status is 1.
69 ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,
70 (val & WDTCTRL_STATUS),
71 0, WDTST_TIMEOUT);
73 return ret;
76 static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)
78 unsigned int val;
79 int ret;
81 ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
82 !(val & WDTCTRL_STATUS),
83 0, WDTST_TIMEOUT);
84 if (ret)
85 return ret;
87 /* Setup period */
88 ret = regmap_write(regmap, WDTTIMSET,
89 SEC_TO_WDTTIMSET_PRD(sec));
90 if (ret)
91 return ret;
93 /* Enable and clear watchdog */
94 ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR);
95 if (!ret)
97 * As SoC specification, after clear counter,
98 * it needs to wait until counter status is 1.
100 ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
101 (val & WDTCTRL_STATUS),
102 0, WDTST_TIMEOUT);
104 return ret;
107 static int __uniphier_watchdog_stop(struct regmap *regmap)
109 /* Disable and stop watchdog */
110 return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);
113 static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)
115 int ret;
117 ret = __uniphier_watchdog_stop(regmap);
118 if (ret)
119 return ret;
121 return __uniphier_watchdog_start(regmap, sec);
124 static int uniphier_watchdog_start(struct watchdog_device *w)
126 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
127 unsigned int tmp_timeout;
129 tmp_timeout = roundup_pow_of_two(w->timeout);
131 return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);
134 static int uniphier_watchdog_stop(struct watchdog_device *w)
136 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
138 return __uniphier_watchdog_stop(wdev->regmap);
141 static int uniphier_watchdog_set_timeout(struct watchdog_device *w,
142 unsigned int t)
144 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
145 unsigned int tmp_timeout;
146 int ret;
148 tmp_timeout = roundup_pow_of_two(t);
149 if (tmp_timeout == w->timeout)
150 return 0;
152 if (watchdog_active(w)) {
153 ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);
154 if (ret)
155 return ret;
158 w->timeout = tmp_timeout;
160 return 0;
164 * Kernel Interfaces
166 static const struct watchdog_info uniphier_wdt_info = {
167 .identity = "uniphier-wdt",
168 .options = WDIOF_SETTIMEOUT |
169 WDIOF_KEEPALIVEPING |
170 WDIOF_MAGICCLOSE |
171 WDIOF_OVERHEAT,
174 static const struct watchdog_ops uniphier_wdt_ops = {
175 .owner = THIS_MODULE,
176 .start = uniphier_watchdog_start,
177 .stop = uniphier_watchdog_stop,
178 .ping = uniphier_watchdog_ping,
179 .set_timeout = uniphier_watchdog_set_timeout,
182 static int uniphier_wdt_probe(struct platform_device *pdev)
184 struct device *dev = &pdev->dev;
185 struct uniphier_wdt_dev *wdev;
186 struct regmap *regmap;
187 struct device_node *parent;
188 int ret;
190 wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);
191 if (!wdev)
192 return -ENOMEM;
194 parent = of_get_parent(dev->of_node); /* parent should be syscon node */
195 regmap = syscon_node_to_regmap(parent);
196 of_node_put(parent);
197 if (IS_ERR(regmap))
198 return PTR_ERR(regmap);
200 wdev->regmap = regmap;
201 wdev->wdt_dev.info = &uniphier_wdt_info;
202 wdev->wdt_dev.ops = &uniphier_wdt_ops;
203 wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;
204 wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;
205 wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;
206 wdev->wdt_dev.parent = dev;
208 watchdog_init_timeout(&wdev->wdt_dev, timeout, dev);
209 watchdog_set_nowayout(&wdev->wdt_dev, nowayout);
210 watchdog_stop_on_reboot(&wdev->wdt_dev);
212 watchdog_set_drvdata(&wdev->wdt_dev, wdev);
214 uniphier_watchdog_stop(&wdev->wdt_dev);
215 ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);
216 if (ret)
217 return ret;
219 ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);
220 if (ret)
221 return ret;
223 dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",
224 wdev->wdt_dev.timeout, nowayout);
226 return 0;
229 static const struct of_device_id uniphier_wdt_dt_ids[] = {
230 { .compatible = "socionext,uniphier-wdt" },
231 { /* sentinel */ }
233 MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);
235 static struct platform_driver uniphier_wdt_driver = {
236 .probe = uniphier_wdt_probe,
237 .driver = {
238 .name = "uniphier-wdt",
239 .of_match_table = uniphier_wdt_dt_ids,
243 module_platform_driver(uniphier_wdt_driver);
245 module_param(timeout, uint, 0000);
246 MODULE_PARM_DESC(timeout,
247 "Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="
248 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
250 module_param(nowayout, bool, 0000);
251 MODULE_PARM_DESC(nowayout,
252 "Watchdog cannot be stopped once started (default="
253 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
255 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
256 MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");
257 MODULE_LICENSE("GPL v2");