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Atsushi Nemoto6f702fc2007-11-12 01:32:17 +09001/*
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 */
Joe Perches27c766a2012-02-15 15:06:19 -080010
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090013#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/types.h>
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090016#include <linux/watchdog.h>
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090017#include <linux/init.h>
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090018#include <linux/platform_device.h>
19#include <linux/clk.h>
20#include <linux/err.h>
21#include <linux/io.h>
22#include <asm/txx9tmr.h>
23
Wim Van Sebroeckb92c8032012-03-23 11:48:22 +010024#define WD_TIMER_CCD 7 /* 1/256 */
25#define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
26#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090027#define TIMER_MARGIN 60 /* Default is 60 seconds */
28
Wim Van Sebroeckb92c8032012-03-23 11:48:22 +010029static unsigned int timeout = TIMER_MARGIN; /* in seconds */
30module_param(timeout, uint, 0);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090031MODULE_PARM_DESC(timeout,
32 "Watchdog timeout in seconds. "
33 "(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), "
34 "default=" __MODULE_STRING(TIMER_MARGIN) ")");
35
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010036static bool nowayout = WATCHDOG_NOWAYOUT;
37module_param(nowayout, bool, 0);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090038MODULE_PARM_DESC(nowayout,
39 "Watchdog cannot be stopped once started "
40 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
41
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090042static struct txx9_tmr_reg __iomem *txx9wdt_reg;
43static struct clk *txx9_imclk;
Adrian Bunkf8494e02008-08-08 18:18:46 +030044static DEFINE_SPINLOCK(txx9_lock);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090045
Axel Lind6245842012-03-16 11:53:53 +080046static int txx9wdt_ping(struct watchdog_device *wdt_dev)
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090047{
Alan Cox8dc244f2008-05-19 14:09:12 +010048 spin_lock(&txx9_lock);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090049 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
Alan Cox8dc244f2008-05-19 14:09:12 +010050 spin_unlock(&txx9_lock);
Axel Lind6245842012-03-16 11:53:53 +080051 return 0;
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090052}
53
Axel Lind6245842012-03-16 11:53:53 +080054static int txx9wdt_start(struct watchdog_device *wdt_dev)
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090055{
Alan Cox8dc244f2008-05-19 14:09:12 +010056 spin_lock(&txx9_lock);
Wim Van Sebroeckb92c8032012-03-23 11:48:22 +010057 __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090058 __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
59 __raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */
60 __raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG,
61 &txx9wdt_reg->tcr);
62 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
Alan Cox8dc244f2008-05-19 14:09:12 +010063 spin_unlock(&txx9_lock);
Axel Lind6245842012-03-16 11:53:53 +080064 return 0;
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090065}
66
Axel Lind6245842012-03-16 11:53:53 +080067static int txx9wdt_stop(struct watchdog_device *wdt_dev)
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090068{
Alan Cox8dc244f2008-05-19 14:09:12 +010069 spin_lock(&txx9_lock);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090070 __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
71 __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
72 &txx9wdt_reg->tcr);
Alan Cox8dc244f2008-05-19 14:09:12 +010073 spin_unlock(&txx9_lock);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090074 return 0;
75}
76
Axel Lind6245842012-03-16 11:53:53 +080077static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
78 unsigned int new_timeout)
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090079{
Wim Van Sebroeckb92c8032012-03-23 11:48:22 +010080 wdt_dev->timeout = new_timeout;
Axel Lind6245842012-03-16 11:53:53 +080081 txx9wdt_stop(wdt_dev);
82 txx9wdt_start(wdt_dev);
83 return 0;
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090084}
85
Axel Lind6245842012-03-16 11:53:53 +080086static const struct watchdog_info txx9wdt_info = {
87 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
88 .identity = "Hardware Watchdog for TXx9",
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +090089};
90
Axel Lind6245842012-03-16 11:53:53 +080091static const struct watchdog_ops txx9wdt_ops = {
92 .owner = THIS_MODULE,
93 .start = txx9wdt_start,
94 .stop = txx9wdt_stop,
95 .ping = txx9wdt_ping,
96 .set_timeout = txx9wdt_set_timeout,
97};
98
99static struct watchdog_device txx9wdt = {
100 .info = &txx9wdt_info,
101 .ops = &txx9wdt_ops,
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900102};
103
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900104static int __init txx9wdt_probe(struct platform_device *dev)
105{
106 struct resource *res;
107 int ret;
108
109 txx9_imclk = clk_get(NULL, "imbus_clk");
110 if (IS_ERR(txx9_imclk)) {
111 ret = PTR_ERR(txx9_imclk);
112 txx9_imclk = NULL;
113 goto exit;
114 }
115 ret = clk_enable(txx9_imclk);
116 if (ret) {
117 clk_put(txx9_imclk);
118 txx9_imclk = NULL;
119 goto exit;
120 }
121
122 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
Thierry Reding4c271bb2013-01-21 11:09:25 +0100123 txx9wdt_reg = devm_ioremap_resource(&dev->dev, res);
124 if (IS_ERR(txx9wdt_reg)) {
125 ret = PTR_ERR(txx9wdt_reg);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900126 goto exit;
127 }
128
Wim Van Sebroeckb92c8032012-03-23 11:48:22 +0100129 if (timeout < 1 || timeout > WD_MAX_TIMEOUT)
130 timeout = TIMER_MARGIN;
131 txx9wdt.timeout = timeout;
Axel Lind6245842012-03-16 11:53:53 +0800132 txx9wdt.min_timeout = 1;
133 txx9wdt.max_timeout = WD_MAX_TIMEOUT;
134 watchdog_set_nowayout(&txx9wdt, nowayout);
135
136 ret = watchdog_register_device(&txx9wdt);
137 if (ret)
138 goto exit;
139
Joe Perches27c766a2012-02-15 15:06:19 -0800140 pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
141 timeout, WD_MAX_TIMEOUT, nowayout);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900142
143 return 0;
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900144exit:
145 if (txx9_imclk) {
146 clk_disable(txx9_imclk);
147 clk_put(txx9_imclk);
148 }
149 return ret;
150}
151
152static int __exit txx9wdt_remove(struct platform_device *dev)
153{
Axel Lind6245842012-03-16 11:53:53 +0800154 watchdog_unregister_device(&txx9wdt);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900155 clk_disable(txx9_imclk);
156 clk_put(txx9_imclk);
157 return 0;
158}
159
Wim Van Sebroeck168b5252009-12-26 19:13:00 +0000160static void txx9wdt_shutdown(struct platform_device *dev)
161{
Axel Lind6245842012-03-16 11:53:53 +0800162 txx9wdt_stop(&txx9wdt);
Wim Van Sebroeck168b5252009-12-26 19:13:00 +0000163}
164
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900165static struct platform_driver txx9wdt_driver = {
166 .remove = __exit_p(txx9wdt_remove),
Wim Van Sebroeck168b5252009-12-26 19:13:00 +0000167 .shutdown = txx9wdt_shutdown,
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900168 .driver = {
169 .name = "txx9wdt",
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900170 },
171};
172
Fabio Porcedda1cb92042013-01-09 12:15:27 +0100173module_platform_driver_probe(txx9wdt_driver, txx9wdt_probe);
Atsushi Nemoto6f702fc2007-11-12 01:32:17 +0900174
175MODULE_DESCRIPTION("TXx9 Watchdog Driver");
176MODULE_LICENSE("GPL");
Kay Sieversf37d1932008-04-10 21:29:23 -0700177MODULE_ALIAS("platform:txx9wdt");