2 * drivers/watchdog/orion_wdt.c
4 * Watchdog driver for Orion/Kirkwood processors
6 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/platform_device.h>
20 #include <linux/watchdog.h>
22 #include <linux/spinlock.h>
23 #include <linux/clk.h>
24 #include <linux/err.h>
26 #include <mach/bridge-regs.h>
29 * Watchdog timer block registers.
31 #define TIMER_CTRL 0x0000
33 #define WDT_VAL 0x0024
35 #define WDT_MAX_CYCLE_COUNT 0xffffffff
37 #define WDT_OK_TO_CLOSE 1
39 #define WDT_RESET_OUT_EN BIT(1)
40 #define WDT_INT_REQ BIT(3)
42 static bool nowayout = WATCHDOG_NOWAYOUT;
43 static int heartbeat = -1; /* module parameter (seconds) */
44 static unsigned int wdt_max_duration; /* (seconds) */
45 static struct clk *clk;
46 static unsigned int wdt_tclk;
47 static void __iomem *wdt_reg;
48 static DEFINE_SPINLOCK(wdt_lock);
50 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
54 /* Reload watchdog duration */
55 writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
57 spin_unlock(&wdt_lock);
61 static int orion_wdt_start(struct watchdog_device *wdt_dev)
67 /* Set watchdog duration */
68 writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
70 /* Clear watchdog timer interrupt */
71 writel(~WDT_INT_REQ, BRIDGE_CAUSE);
73 /* Enable watchdog timer */
74 reg = readl(wdt_reg + TIMER_CTRL);
76 writel(reg, wdt_reg + TIMER_CTRL);
78 /* Enable reset on watchdog */
79 reg = readl(RSTOUTn_MASK);
80 reg |= WDT_RESET_OUT_EN;
81 writel(reg, RSTOUTn_MASK);
83 spin_unlock(&wdt_lock);
87 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
93 /* Disable reset on watchdog */
94 reg = readl(RSTOUTn_MASK);
95 reg &= ~WDT_RESET_OUT_EN;
96 writel(reg, RSTOUTn_MASK);
98 /* Disable watchdog timer */
99 reg = readl(wdt_reg + TIMER_CTRL);
101 writel(reg, wdt_reg + TIMER_CTRL);
103 spin_unlock(&wdt_lock);
107 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
109 unsigned int time_left;
111 spin_lock(&wdt_lock);
112 time_left = readl(wdt_reg + WDT_VAL) / wdt_tclk;
113 spin_unlock(&wdt_lock);
118 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
119 unsigned int timeout)
121 wdt_dev->timeout = timeout;
125 static const struct watchdog_info orion_wdt_info = {
126 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
127 .identity = "Orion Watchdog",
130 static const struct watchdog_ops orion_wdt_ops = {
131 .owner = THIS_MODULE,
132 .start = orion_wdt_start,
133 .stop = orion_wdt_stop,
134 .ping = orion_wdt_ping,
135 .set_timeout = orion_wdt_set_timeout,
136 .get_timeleft = orion_wdt_get_timeleft,
139 static struct watchdog_device orion_wdt = {
140 .info = &orion_wdt_info,
141 .ops = &orion_wdt_ops,
145 static int orion_wdt_probe(struct platform_device *pdev)
147 struct resource *res;
150 clk = devm_clk_get(&pdev->dev, NULL);
152 dev_err(&pdev->dev, "Orion Watchdog missing clock\n");
155 clk_prepare_enable(clk);
156 wdt_tclk = clk_get_rate(clk);
158 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
161 wdt_reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
165 wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
167 orion_wdt.timeout = wdt_max_duration;
168 orion_wdt.max_timeout = wdt_max_duration;
169 watchdog_init_timeout(&orion_wdt, heartbeat, &pdev->dev);
171 watchdog_set_nowayout(&orion_wdt, nowayout);
172 ret = watchdog_register_device(&orion_wdt);
174 clk_disable_unprepare(clk);
178 pr_info("Initial timeout %d sec%s\n",
179 orion_wdt.timeout, nowayout ? ", nowayout" : "");
183 static int orion_wdt_remove(struct platform_device *pdev)
185 watchdog_unregister_device(&orion_wdt);
186 clk_disable_unprepare(clk);
190 static void orion_wdt_shutdown(struct platform_device *pdev)
192 orion_wdt_stop(&orion_wdt);
195 static const struct of_device_id orion_wdt_of_match_table[] = {
196 { .compatible = "marvell,orion-wdt", },
199 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
201 static struct platform_driver orion_wdt_driver = {
202 .probe = orion_wdt_probe,
203 .remove = orion_wdt_remove,
204 .shutdown = orion_wdt_shutdown,
206 .owner = THIS_MODULE,
208 .of_match_table = orion_wdt_of_match_table,
212 module_platform_driver(orion_wdt_driver);
214 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
215 MODULE_DESCRIPTION("Orion Processor Watchdog");
217 module_param(heartbeat, int, 0);
218 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
220 module_param(nowayout, bool, 0);
221 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
222 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
224 MODULE_LICENSE("GPL");
225 MODULE_ALIAS("platform:orion_wdt");