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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/watchdog.h>
17#include <linux/init.h>
18#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
24#define WD_TIMER_CCD 7
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)
27#define TIMER_MARGIN 60
28
29static unsigned int timeout = TIMER_MARGIN;
30module_param(timeout, uint, 0);
31MODULE_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
36static bool nowayout = WATCHDOG_NOWAYOUT;
37module_param(nowayout, bool, 0);
38MODULE_PARM_DESC(nowayout,
39 "Watchdog cannot be stopped once started "
40 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
41
42static struct txx9_tmr_reg __iomem *txx9wdt_reg;
43static struct clk *txx9_imclk;
44static DEFINE_SPINLOCK(txx9_lock);
45
46static int txx9wdt_ping(struct watchdog_device *wdt_dev)
47{
48 spin_lock(&txx9_lock);
49 __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
50 spin_unlock(&txx9_lock);
51 return 0;
52}
53
54static int txx9wdt_start(struct watchdog_device *wdt_dev)
55{
56 spin_lock(&txx9_lock);
57 __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra);
58 __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
59 __raw_writel(0, &txx9wdt_reg->tisr);
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);
63 spin_unlock(&txx9_lock);
64 return 0;
65}
66
67static int txx9wdt_stop(struct watchdog_device *wdt_dev)
68{
69 spin_lock(&txx9_lock);
70 __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
71 __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
72 &txx9wdt_reg->tcr);
73 spin_unlock(&txx9_lock);
74 return 0;
75}
76
77static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
78 unsigned int new_timeout)
79{
80 wdt_dev->timeout = new_timeout;
81 txx9wdt_stop(wdt_dev);
82 txx9wdt_start(wdt_dev);
83 return 0;
84}
85
86static const struct watchdog_info txx9wdt_info = {
87 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
88 .identity = "Hardware Watchdog for TXx9",
89};
90
91static 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,
102};
103
104static 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);
123 txx9wdt_reg = devm_ioremap_resource(&dev->dev, res);
124 if (IS_ERR(txx9wdt_reg)) {
125 ret = PTR_ERR(txx9wdt_reg);
126 goto exit;
127 }
128
129 if (timeout < 1 || timeout > WD_MAX_TIMEOUT)
130 timeout = TIMER_MARGIN;
131 txx9wdt.timeout = timeout;
132 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
140 pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
141 timeout, WD_MAX_TIMEOUT, nowayout);
142
143 return 0;
144exit:
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{
154 watchdog_unregister_device(&txx9wdt);
155 clk_disable(txx9_imclk);
156 clk_put(txx9_imclk);
157 return 0;
158}
159
160static void txx9wdt_shutdown(struct platform_device *dev)
161{
162 txx9wdt_stop(&txx9wdt);
163}
164
165static struct platform_driver txx9wdt_driver = {
166 .remove = __exit_p(txx9wdt_remove),
167 .shutdown = txx9wdt_shutdown,
168 .driver = {
169 .name = "txx9wdt",
170 .owner = THIS_MODULE,
171 },
172};
173
174module_platform_driver_probe(txx9wdt_driver, txx9wdt_probe);
175
176MODULE_DESCRIPTION("TXx9 Watchdog Driver");
177MODULE_LICENSE("GPL");
178MODULE_ALIAS("platform:txx9wdt");
179
