1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* Copyright (c) 2016 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define DEFAULT_TIMEOUT 30 /* seconds */
#define GXBB_WDT_CTRL_REG 0x0
#define GXBB_WDT_TCNT_REG 0x8
#define GXBB_WDT_RSET_REG 0xc
#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
#define GXBB_WDT_CTRL_CLK_EN BIT(24)
#define GXBB_WDT_CTRL_EE_RESET BIT(21)
#define GXBB_WDT_CTRL_EN BIT(18)
#define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1)
#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1)
#define GXBB_WDT_TCNT_CNT_SHIFT 16
struct meson_gxbb_wdt {
void __iomem *reg_base;
struct watchdog_device wdt_dev;
struct clk *clk;
};
static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
data->reg_base + GXBB_WDT_CTRL_REG);
return 0;
}
static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
data->reg_base + GXBB_WDT_CTRL_REG);
return 0;
}
static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
writel(0, data->reg_base + GXBB_WDT_RSET_REG);
return 0;
}
static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
unsigned long tcnt = timeout * 1000;
if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
tcnt = GXBB_WDT_TCNT_SETUP_MASK;
wdt_dev->timeout = timeout;
meson_gxbb_wdt_ping(wdt_dev);
writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);
return 0;
}
static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
unsigned long reg;
reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) -
(reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
}
static const struct watchdog_ops meson_gxbb_wdt_ops = {
.start = meson_gxbb_wdt_start,
.stop = meson_gxbb_wdt_stop,
.ping = meson_gxbb_wdt_ping,
.set_timeout = meson_gxbb_wdt_set_timeout,
.get_timeleft = meson_gxbb_wdt_get_timeleft,
};
static const struct watchdog_info meson_gxbb_wdt_info = {
.identity = "Meson GXBB Watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
{
struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
if (watchdog_active(&data->wdt_dev))
meson_gxbb_wdt_start(&data->wdt_dev);
return 0;
}
static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
{
struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
if (watchdog_active(&data->wdt_dev))
meson_gxbb_wdt_stop(&data->wdt_dev);
return 0;
}
static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
};
static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
{ .compatible = "amlogic,meson-gxbb-wdt", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
static int meson_gxbb_wdt_probe(struct platform_device *pdev)
{
struct meson_gxbb_wdt *data;
struct resource *res;
int ret;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->reg_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->reg_base))
return PTR_ERR(data->reg_base);
data->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(data->clk))
return PTR_ERR(data->clk);
ret = clk_prepare_enable(data->clk);
if (ret)
return ret;
platform_set_drvdata(pdev, data);
data->wdt_dev.parent = &pdev->dev;
data->wdt_dev.info = &meson_gxbb_wdt_info;
data->wdt_dev.ops = &meson_gxbb_wdt_ops;
data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
data->wdt_dev.min_timeout = 1;
data->wdt_dev.timeout = DEFAULT_TIMEOUT;
watchdog_set_drvdata(&data->wdt_dev, data);
/* Setup with 1ms timebase */
writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
GXBB_WDT_CTRL_EE_RESET |
GXBB_WDT_CTRL_CLK_EN |
GXBB_WDT_CTRL_CLKDIV_EN,
data->reg_base + GXBB_WDT_CTRL_REG);
meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
ret = watchdog_register_device(&data->wdt_dev);
if (ret) {
clk_disable_unprepare(data->clk);
return ret;
}
return 0;
}
static int meson_gxbb_wdt_remove(struct platform_device *pdev)
{
struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
watchdog_unregister_device(&data->wdt_dev);
clk_disable_unprepare(data->clk);
return 0;
}
static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
{
struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
meson_gxbb_wdt_stop(&data->wdt_dev);
}
static struct platform_driver meson_gxbb_wdt_driver = {
.probe = meson_gxbb_wdt_probe,
.remove = meson_gxbb_wdt_remove,
.shutdown = meson_gxbb_wdt_shutdown,
.driver = {
.name = "meson-gxbb-wdt",
.pm = &meson_gxbb_wdt_pm_ops,
.of_match_table = meson_gxbb_wdt_dt_ids,
},
};
module_platform_driver(meson_gxbb_wdt_driver);
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
MODULE_LICENSE("Dual BSD/GPL");
|
