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Marcus Folkesson2e62c492018-03-16 16:14:11 +01001// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
Neil Armstrong683fa502016-07-10 11:11:04 +02002/*
Neil Armstrong683fa502016-07-10 11:11:04 +02003 * Copyright (c) 2016 BayLibre, SAS.
4 * Author: Neil Armstrong <narmstrong@baylibre.com>
5 *
Neil Armstrong683fa502016-07-10 11:11:04 +02006 */
7#include <linux/clk.h>
8#include <linux/err.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/types.h>
15#include <linux/watchdog.h>
16
17#define DEFAULT_TIMEOUT 30 /* seconds */
18
19#define GXBB_WDT_CTRL_REG 0x0
20#define GXBB_WDT_TCNT_REG 0x8
21#define GXBB_WDT_RSET_REG 0xc
22
23#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
24#define GXBB_WDT_CTRL_CLK_EN BIT(24)
25#define GXBB_WDT_CTRL_EE_RESET BIT(21)
26#define GXBB_WDT_CTRL_EN BIT(18)
27#define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1)
28
29#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1)
30#define GXBB_WDT_TCNT_CNT_SHIFT 16
31
Artem Lapkinbb6d7722021-07-30 12:13:53 +080032static bool nowayout = WATCHDOG_NOWAYOUT;
33module_param(nowayout, bool, 0);
34MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
35 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
36
Artem Lapkinf01f07172021-07-30 12:13:54 +080037static unsigned int timeout;
38module_param(timeout, uint, 0);
39MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds="
40 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
41
Neil Armstrong683fa502016-07-10 11:11:04 +020042struct meson_gxbb_wdt {
43 void __iomem *reg_base;
44 struct watchdog_device wdt_dev;
45 struct clk *clk;
46};
47
48static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
49{
50 struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
51
52 writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
53 data->reg_base + GXBB_WDT_CTRL_REG);
54
55 return 0;
56}
57
58static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
59{
60 struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
61
62 writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
63 data->reg_base + GXBB_WDT_CTRL_REG);
64
65 return 0;
66}
67
68static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
69{
70 struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
71
72 writel(0, data->reg_base + GXBB_WDT_RSET_REG);
73
74 return 0;
75}
76
77static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
78 unsigned int timeout)
79{
80 struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
81 unsigned long tcnt = timeout * 1000;
82
83 if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
84 tcnt = GXBB_WDT_TCNT_SETUP_MASK;
85
86 wdt_dev->timeout = timeout;
87
88 meson_gxbb_wdt_ping(wdt_dev);
89
90 writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);
91
92 return 0;
93}
94
95static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
96{
97 struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
98 unsigned long reg;
99
100 reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
101
Xingyu Chen2c777342019-09-29 18:53:49 +0800102 return ((reg & GXBB_WDT_TCNT_SETUP_MASK) -
103 (reg >> GXBB_WDT_TCNT_CNT_SHIFT)) / 1000;
Neil Armstrong683fa502016-07-10 11:11:04 +0200104}
105
106static const struct watchdog_ops meson_gxbb_wdt_ops = {
107 .start = meson_gxbb_wdt_start,
108 .stop = meson_gxbb_wdt_stop,
109 .ping = meson_gxbb_wdt_ping,
110 .set_timeout = meson_gxbb_wdt_set_timeout,
111 .get_timeleft = meson_gxbb_wdt_get_timeleft,
112};
113
114static const struct watchdog_info meson_gxbb_wdt_info = {
115 .identity = "Meson GXBB Watchdog",
116 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
117};
118
119static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
120{
121 struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
122
123 if (watchdog_active(&data->wdt_dev))
124 meson_gxbb_wdt_start(&data->wdt_dev);
125
126 return 0;
127}
128
129static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
130{
131 struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
132
133 if (watchdog_active(&data->wdt_dev))
134 meson_gxbb_wdt_stop(&data->wdt_dev);
135
136 return 0;
137}
138
139static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
140 SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
141};
142
143static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
144 { .compatible = "amlogic,meson-gxbb-wdt", },
145 { /* sentinel */ },
146};
147MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
148
149static int meson_gxbb_wdt_probe(struct platform_device *pdev)
150{
Guenter Roeck1678f832019-04-09 10:23:42 -0700151 struct device *dev = &pdev->dev;
Neil Armstrong683fa502016-07-10 11:11:04 +0200152 struct meson_gxbb_wdt *data;
Philippe Boos6adbfba2022-08-01 11:21:50 +0200153 u32 ctrl_reg;
Neil Armstrong683fa502016-07-10 11:11:04 +0200154
Guenter Roeck1678f832019-04-09 10:23:42 -0700155 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
Neil Armstrong683fa502016-07-10 11:11:04 +0200156 if (!data)
157 return -ENOMEM;
158
Guenter Roeck0f0a6a22019-04-02 12:01:53 -0700159 data->reg_base = devm_platform_ioremap_resource(pdev, 0);
Neil Armstrong683fa502016-07-10 11:11:04 +0200160 if (IS_ERR(data->reg_base))
161 return PTR_ERR(data->reg_base);
162
Christophe JAILLET2cf46c62022-12-31 13:34:44 +0100163 data->clk = devm_clk_get_enabled(dev, NULL);
Neil Armstrong683fa502016-07-10 11:11:04 +0200164 if (IS_ERR(data->clk))
165 return PTR_ERR(data->clk);
166
Neil Armstrong683fa502016-07-10 11:11:04 +0200167 platform_set_drvdata(pdev, data);
168
Guenter Roeck1678f832019-04-09 10:23:42 -0700169 data->wdt_dev.parent = dev;
Neil Armstrong683fa502016-07-10 11:11:04 +0200170 data->wdt_dev.info = &meson_gxbb_wdt_info;
171 data->wdt_dev.ops = &meson_gxbb_wdt_ops;
172 data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
173 data->wdt_dev.min_timeout = 1;
174 data->wdt_dev.timeout = DEFAULT_TIMEOUT;
Artem Lapkinf01f07172021-07-30 12:13:54 +0800175 watchdog_init_timeout(&data->wdt_dev, timeout, dev);
Artem Lapkinbb6d7722021-07-30 12:13:53 +0800176 watchdog_set_nowayout(&data->wdt_dev, nowayout);
Neil Armstrong683fa502016-07-10 11:11:04 +0200177 watchdog_set_drvdata(&data->wdt_dev, data);
178
Philippe Boos6adbfba2022-08-01 11:21:50 +0200179 ctrl_reg = readl(data->reg_base + GXBB_WDT_CTRL_REG) &
180 GXBB_WDT_CTRL_EN;
Neil Armstrong683fa502016-07-10 11:11:04 +0200181
Philippe Boos6adbfba2022-08-01 11:21:50 +0200182 if (ctrl_reg) {
183 /* Watchdog is running - keep it running but extend timeout
184 * to the maximum while setting the timebase
185 */
186 set_bit(WDOG_HW_RUNNING, &data->wdt_dev.status);
187 meson_gxbb_wdt_set_timeout(&data->wdt_dev,
188 GXBB_WDT_TCNT_SETUP_MASK / 1000);
189 }
190
191 /* Setup with 1ms timebase */
192 ctrl_reg |= ((clk_get_rate(data->clk) / 1000) &
193 GXBB_WDT_CTRL_DIV_MASK) |
194 GXBB_WDT_CTRL_EE_RESET |
195 GXBB_WDT_CTRL_CLK_EN |
196 GXBB_WDT_CTRL_CLKDIV_EN;
197
198 writel(ctrl_reg, data->reg_base + GXBB_WDT_CTRL_REG);
Neil Armstrong683fa502016-07-10 11:11:04 +0200199 meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
200
Guenter Roeck1678f832019-04-09 10:23:42 -0700201 return devm_watchdog_register_device(dev, &data->wdt_dev);
Neil Armstrong683fa502016-07-10 11:11:04 +0200202}
203
204static struct platform_driver meson_gxbb_wdt_driver = {
205 .probe = meson_gxbb_wdt_probe,
Neil Armstrong683fa502016-07-10 11:11:04 +0200206 .driver = {
207 .name = "meson-gxbb-wdt",
208 .pm = &meson_gxbb_wdt_pm_ops,
209 .of_match_table = meson_gxbb_wdt_dt_ids,
210 },
211};
212
213module_platform_driver(meson_gxbb_wdt_driver);
214
Neil Armstrong683fa502016-07-10 11:11:04 +0200215MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
216MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
217MODULE_LICENSE("Dual BSD/GPL");