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1/*
2 * txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs
3 *
4 * Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/types.h>
16#include <linux/miscdevice.h>
17#include <linux/watchdog.h>
18#include <linux/init.h>
19#include <linux/platform_device.h>
20#include <linux/clk.h>
21#include <linux/err.h>
22#include <linux/io.h>
23#include <asm/txx9tmr.h>
24
25#define WD_TIMER_CCD 7 /* 1/256 */
26#define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
27#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)
28#define TIMER_MARGIN 60 /* Default is 60 seconds */
29
30static unsigned int timeout = TIMER_MARGIN; /* in seconds */
31module_param(timeout, uint, 0);
32MODULE_PARM_DESC(timeout,
33 "Watchdog timeout in seconds. "
34 "(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), "
35 "default=" __MODULE_STRING(TIMER_MARGIN) ")");
36
37static bool nowayout = WATCHDOG_NOWAYOUT;
38module_param(nowayout, bool, 0);
39MODULE_PARM_DESC(nowayout,
40 "Watchdog cannot be stopped once started "
41 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
42
43static struct txx9_tmr_reg __iomem *txx9wdt_reg;
44static struct clk *txx9_imclk;
45static DEFINE_SPINLOCK(txx9_lock);
46
47static int txx9wdt_ping(struct watchdog_device *wdt_dev)
48{
49 spin_lock(&txx9_lock);
50 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
51 spin_unlock(&txx9_lock);
52 return 0;
53}
54
55static int txx9wdt_start(struct watchdog_device *wdt_dev)
56{
57 spin_lock(&txx9_lock);
58 __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra);
59 __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
60 __raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */
61 __raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG,
62 &txx9wdt_reg->tcr);
63 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
64 spin_unlock(&txx9_lock);
65 return 0;
66}
67
68static int txx9wdt_stop(struct watchdog_device *wdt_dev)
69{
70 spin_lock(&txx9_lock);
71 __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
72 __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
73 &txx9wdt_reg->tcr);
74 spin_unlock(&txx9_lock);
75 return 0;
76}
77
78static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
79 unsigned int new_timeout)
80{
81 wdt_dev->timeout = new_timeout;
82 txx9wdt_stop(wdt_dev);
83 txx9wdt_start(wdt_dev);
84 return 0;
85}
86
87static const struct watchdog_info txx9wdt_info = {
88 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
89 .identity = "Hardware Watchdog for TXx9",
90};
91
92static const struct watchdog_ops txx9wdt_ops = {
93 .owner = THIS_MODULE,
94 .start = txx9wdt_start,
95 .stop = txx9wdt_stop,
96 .ping = txx9wdt_ping,
97 .set_timeout = txx9wdt_set_timeout,
98};
99
100static struct watchdog_device txx9wdt = {
101 .info = &txx9wdt_info,
102 .ops = &txx9wdt_ops,
103};
104
105static int __init txx9wdt_probe(struct platform_device *dev)
106{
107 struct resource *res;
108 int ret;
109
110 txx9_imclk = clk_get(NULL, "imbus_clk");
111 if (IS_ERR(txx9_imclk)) {
112 ret = PTR_ERR(txx9_imclk);
113 txx9_imclk = NULL;
114 goto exit;
115 }
116 ret = clk_enable(txx9_imclk);
117 if (ret) {
118 clk_put(txx9_imclk);
119 txx9_imclk = NULL;
120 goto exit;
121 }
122
123 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
124 txx9wdt_reg = devm_request_and_ioremap(&dev->dev, res);
125 if (!txx9wdt_reg) {
126 ret = -EBUSY;
127 goto exit;
128 }
129
130 if (timeout < 1 || timeout > WD_MAX_TIMEOUT)
131 timeout = TIMER_MARGIN;
132 txx9wdt.timeout = timeout;
133 txx9wdt.min_timeout = 1;
134 txx9wdt.max_timeout = WD_MAX_TIMEOUT;
135 watchdog_set_nowayout(&txx9wdt, nowayout);
136
137 ret = watchdog_register_device(&txx9wdt);
138 if (ret)
139 goto exit;
140
141 pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
142 timeout, WD_MAX_TIMEOUT, nowayout);
143
144 return 0;
145exit:
146 if (txx9_imclk) {
147 clk_disable(txx9_imclk);
148 clk_put(txx9_imclk);
149 }
150 return ret;
151}
152
153static int __exit txx9wdt_remove(struct platform_device *dev)
154{
155 watchdog_unregister_device(&txx9wdt);
156 clk_disable(txx9_imclk);
157 clk_put(txx9_imclk);
158 return 0;
159}
160
161static void txx9wdt_shutdown(struct platform_device *dev)
162{
163 txx9wdt_stop(&txx9wdt);
164}
165
166static struct platform_driver txx9wdt_driver = {
167 .remove = __exit_p(txx9wdt_remove),
168 .shutdown = txx9wdt_shutdown,
169 .driver = {
170 .name = "txx9wdt",
171 .owner = THIS_MODULE,
172 },
173};
174
175static int __init watchdog_init(void)
176{
177 return platform_driver_probe(&txx9wdt_driver, txx9wdt_probe);
178}
179
180static void __exit watchdog_exit(void)
181{
182 platform_driver_unregister(&txx9wdt_driver);
183}
184
185module_init(watchdog_init);
186module_exit(watchdog_exit);
187
188MODULE_DESCRIPTION("TXx9 Watchdog Driver");
189MODULE_LICENSE("GPL");
190MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
191MODULE_ALIAS("platform:txx9wdt");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs
4 *
5 * Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/module.h>
11#include <linux/moduleparam.h>
12#include <linux/types.h>
13#include <linux/watchdog.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/clk.h>
17#include <linux/err.h>
18#include <linux/io.h>
19#include <asm/txx9tmr.h>
20
21#define WD_TIMER_CCD 7 /* 1/256 */
22#define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
23#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)
24#define TIMER_MARGIN 60 /* Default is 60 seconds */
25
26static unsigned int timeout = TIMER_MARGIN; /* in seconds */
27module_param(timeout, uint, 0);
28MODULE_PARM_DESC(timeout,
29 "Watchdog timeout in seconds. "
30 "(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), "
31 "default=" __MODULE_STRING(TIMER_MARGIN) ")");
32
33static bool nowayout = WATCHDOG_NOWAYOUT;
34module_param(nowayout, bool, 0);
35MODULE_PARM_DESC(nowayout,
36 "Watchdog cannot be stopped once started "
37 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
38
39static struct txx9_tmr_reg __iomem *txx9wdt_reg;
40static struct clk *txx9_imclk;
41static DEFINE_SPINLOCK(txx9_lock);
42
43static int txx9wdt_ping(struct watchdog_device *wdt_dev)
44{
45 spin_lock(&txx9_lock);
46 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
47 spin_unlock(&txx9_lock);
48 return 0;
49}
50
51static int txx9wdt_start(struct watchdog_device *wdt_dev)
52{
53 spin_lock(&txx9_lock);
54 __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra);
55 __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
56 __raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */
57 __raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG,
58 &txx9wdt_reg->tcr);
59 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
60 spin_unlock(&txx9_lock);
61 return 0;
62}
63
64static int txx9wdt_stop(struct watchdog_device *wdt_dev)
65{
66 spin_lock(&txx9_lock);
67 __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
68 __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
69 &txx9wdt_reg->tcr);
70 spin_unlock(&txx9_lock);
71 return 0;
72}
73
74static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
75 unsigned int new_timeout)
76{
77 wdt_dev->timeout = new_timeout;
78 txx9wdt_stop(wdt_dev);
79 txx9wdt_start(wdt_dev);
80 return 0;
81}
82
83static const struct watchdog_info txx9wdt_info = {
84 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
85 .identity = "Hardware Watchdog for TXx9",
86};
87
88static const struct watchdog_ops txx9wdt_ops = {
89 .owner = THIS_MODULE,
90 .start = txx9wdt_start,
91 .stop = txx9wdt_stop,
92 .ping = txx9wdt_ping,
93 .set_timeout = txx9wdt_set_timeout,
94};
95
96static struct watchdog_device txx9wdt = {
97 .info = &txx9wdt_info,
98 .ops = &txx9wdt_ops,
99};
100
101static int __init txx9wdt_probe(struct platform_device *dev)
102{
103 int ret;
104
105 txx9_imclk = clk_get(NULL, "imbus_clk");
106 if (IS_ERR(txx9_imclk)) {
107 ret = PTR_ERR(txx9_imclk);
108 txx9_imclk = NULL;
109 goto exit;
110 }
111 ret = clk_prepare_enable(txx9_imclk);
112 if (ret) {
113 clk_put(txx9_imclk);
114 txx9_imclk = NULL;
115 goto exit;
116 }
117
118 txx9wdt_reg = devm_platform_ioremap_resource(dev, 0);
119 if (IS_ERR(txx9wdt_reg)) {
120 ret = PTR_ERR(txx9wdt_reg);
121 goto exit;
122 }
123
124 if (timeout < 1 || timeout > WD_MAX_TIMEOUT)
125 timeout = TIMER_MARGIN;
126 txx9wdt.timeout = timeout;
127 txx9wdt.min_timeout = 1;
128 txx9wdt.max_timeout = WD_MAX_TIMEOUT;
129 txx9wdt.parent = &dev->dev;
130 watchdog_set_nowayout(&txx9wdt, nowayout);
131
132 ret = watchdog_register_device(&txx9wdt);
133 if (ret)
134 goto exit;
135
136 pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
137 timeout, WD_MAX_TIMEOUT, nowayout);
138
139 return 0;
140exit:
141 if (txx9_imclk) {
142 clk_disable_unprepare(txx9_imclk);
143 clk_put(txx9_imclk);
144 }
145 return ret;
146}
147
148static int __exit txx9wdt_remove(struct platform_device *dev)
149{
150 watchdog_unregister_device(&txx9wdt);
151 clk_disable_unprepare(txx9_imclk);
152 clk_put(txx9_imclk);
153 return 0;
154}
155
156static void txx9wdt_shutdown(struct platform_device *dev)
157{
158 txx9wdt_stop(&txx9wdt);
159}
160
161static struct platform_driver txx9wdt_driver = {
162 .remove = __exit_p(txx9wdt_remove),
163 .shutdown = txx9wdt_shutdown,
164 .driver = {
165 .name = "txx9wdt",
166 },
167};
168
169module_platform_driver_probe(txx9wdt_driver, txx9wdt_probe);
170
171MODULE_DESCRIPTION("TXx9 Watchdog Driver");
172MODULE_LICENSE("GPL");
173MODULE_ALIAS("platform:txx9wdt");