2 * intel-mid_wdt: generic Intel MID SCU watchdog driver
4 * Platforms supported so far:
7 * Copyright (C) 2014 Intel Corporation. All rights reserved.
8 * Contact: David Cohen <david.a.cohen@linux.intel.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of version 2 of the GNU General
12 * Public License as published by the Free Software Foundation.
15 #include <linux/interrupt.h>
16 #include <linux/module.h>
17 #include <linux/nmi.h>
18 #include <linux/platform_device.h>
19 #include <linux/watchdog.h>
20 #include <linux/platform_data/intel-mid_wdt.h>
22 #include <asm/intel_scu_ipc.h>
23 #include <asm/intel-mid.h>
25 #define IPC_WATCHDOG 0xf8
27 #define MID_WDT_PRETIMEOUT 15
28 #define MID_WDT_TIMEOUT_MIN (1 + MID_WDT_PRETIMEOUT)
29 #define MID_WDT_TIMEOUT_MAX 170
30 #define MID_WDT_DEFAULT_TIMEOUT 90
32 /* SCU watchdog messages */
34 SCU_WATCHDOG_START = 0,
36 SCU_WATCHDOG_KEEPALIVE,
39 static inline int wdt_command(int sub, u32 *in, int inlen)
41 return intel_scu_ipc_command(IPC_WATCHDOG, sub, in, inlen, NULL, 0);
44 static int wdt_start(struct watchdog_device *wd)
47 int timeout = wd->timeout;
51 } ipc_wd_start = { timeout - MID_WDT_PRETIMEOUT, timeout };
54 * SCU expects the input size for watchdog IPC to
57 in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4);
59 ret = wdt_command(SCU_WATCHDOG_START, (u32 *)&ipc_wd_start, in_size);
61 struct device *dev = watchdog_get_drvdata(wd);
62 dev_crit(dev, "error starting watchdog: %d\n", ret);
68 static int wdt_ping(struct watchdog_device *wd)
72 ret = wdt_command(SCU_WATCHDOG_KEEPALIVE, NULL, 0);
74 struct device *dev = watchdog_get_drvdata(wd);
75 dev_crit(dev, "Error executing keepalive: 0x%x\n", ret);
81 static int wdt_stop(struct watchdog_device *wd)
85 ret = wdt_command(SCU_WATCHDOG_STOP, NULL, 0);
87 struct device *dev = watchdog_get_drvdata(wd);
88 dev_crit(dev, "Error stopping watchdog: 0x%x\n", ret);
94 static irqreturn_t mid_wdt_irq(int irq, void *dev_id)
96 panic("Kernel Watchdog");
98 /* This code should not be reached */
102 static const struct watchdog_info mid_wdt_info = {
103 .identity = "Intel MID SCU watchdog",
104 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
107 static const struct watchdog_ops mid_wdt_ops = {
108 .owner = THIS_MODULE,
114 static int mid_wdt_probe(struct platform_device *pdev)
116 struct watchdog_device *wdt_dev;
117 struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
121 dev_err(&pdev->dev, "missing platform data\n");
126 ret = pdata->probe(pdev);
131 wdt_dev = devm_kzalloc(&pdev->dev, sizeof(*wdt_dev), GFP_KERNEL);
135 wdt_dev->info = &mid_wdt_info;
136 wdt_dev->ops = &mid_wdt_ops;
137 wdt_dev->min_timeout = MID_WDT_TIMEOUT_MIN;
138 wdt_dev->max_timeout = MID_WDT_TIMEOUT_MAX;
139 wdt_dev->timeout = MID_WDT_DEFAULT_TIMEOUT;
141 watchdog_set_drvdata(wdt_dev, &pdev->dev);
142 platform_set_drvdata(pdev, wdt_dev);
144 ret = devm_request_irq(&pdev->dev, pdata->irq, mid_wdt_irq,
145 IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
148 dev_err(&pdev->dev, "error requesting warning irq %d\n",
153 ret = watchdog_register_device(wdt_dev);
155 dev_err(&pdev->dev, "error registering watchdog device\n");
159 dev_info(&pdev->dev, "Intel MID watchdog device probed\n");
164 static int mid_wdt_remove(struct platform_device *pdev)
166 struct watchdog_device *wd = platform_get_drvdata(pdev);
167 watchdog_unregister_device(wd);
171 static struct platform_driver mid_wdt_driver = {
172 .probe = mid_wdt_probe,
173 .remove = mid_wdt_remove,
175 .owner = THIS_MODULE,
176 .name = "intel_mid_wdt",
180 module_platform_driver(mid_wdt_driver);
182 MODULE_AUTHOR("David Cohen <david.a.cohen@linux.intel.com>");
183 MODULE_DESCRIPTION("Watchdog Driver for Intel MID platform");
184 MODULE_LICENSE("GPL");