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Release 4.18 drivers/watchdog/intel-mid_wdt.c

Directory: drivers/watchdog
/*
 *      intel-mid_wdt: generic Intel MID SCU watchdog driver
 *
 *      Platforms supported so far:
 *      - Merrifield only
 *
 *      Copyright (C) 2014 Intel Corporation. All rights reserved.
 *      Contact: David Cohen <david.a.cohen@linux.intel.com>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of version 2 of the GNU General
 *      Public License as published by the Free Software Foundation.
 */

#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/nmi.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/platform_data/intel-mid_wdt.h>

#include <asm/intel_scu_ipc.h>
#include <asm/intel-mid.h>


#define IPC_WATCHDOG 0xf8


#define MID_WDT_PRETIMEOUT		15

#define MID_WDT_TIMEOUT_MIN		(1 + MID_WDT_PRETIMEOUT)

#define MID_WDT_TIMEOUT_MAX		170

#define MID_WDT_DEFAULT_TIMEOUT		90

/* SCU watchdog messages */

enum {
	
SCU_WATCHDOG_START = 0,
	
SCU_WATCHDOG_STOP,
	
SCU_WATCHDOG_KEEPALIVE,
};


static inline int wdt_command(int sub, u32 *in, int inlen) { return intel_scu_ipc_command(IPC_WATCHDOG, sub, in, inlen, NULL, 0); }

Contributors

PersonTokensPropCommitsCommitProp
David Cohen33100.00%1100.00%
Total33100.00%1100.00%


static int wdt_start(struct watchdog_device *wd) { struct device *dev = watchdog_get_drvdata(wd); int ret, in_size; int timeout = wd->timeout; struct ipc_wd_start { u32 pretimeout; u32 timeout; } ipc_wd_start = { timeout - MID_WDT_PRETIMEOUT, timeout }; /* * SCU expects the input size for watchdog IPC to * be based on 4 bytes */ in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4); ret = wdt_command(SCU_WATCHDOG_START, (u32 *)&ipc_wd_start, in_size); if (ret) dev_crit(dev, "error starting watchdog: %d\n", ret); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Cohen8889.80%150.00%
Andy Shevchenko1010.20%150.00%
Total98100.00%2100.00%


static int wdt_ping(struct watchdog_device *wd) { struct device *dev = watchdog_get_drvdata(wd); int ret; ret = wdt_command(SCU_WATCHDOG_KEEPALIVE, NULL, 0); if (ret) dev_crit(dev, "Error executing keepalive: %d\n", ret); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Cohen4078.43%150.00%
Andy Shevchenko1121.57%150.00%
Total51100.00%2100.00%


static int wdt_stop(struct watchdog_device *wd) { struct device *dev = watchdog_get_drvdata(wd); int ret; ret = wdt_command(SCU_WATCHDOG_STOP, NULL, 0); if (ret) dev_crit(dev, "Error stopping watchdog: %d\n", ret); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Cohen4078.43%150.00%
Andy Shevchenko1121.57%150.00%
Total51100.00%2100.00%


static irqreturn_t mid_wdt_irq(int irq, void *dev_id) { panic("Kernel Watchdog"); /* This code should not be reached */ return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
David Cohen22100.00%1100.00%
Total22100.00%1100.00%

static const struct watchdog_info mid_wdt_info = { .identity = "Intel MID SCU watchdog", .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, }; static const struct watchdog_ops mid_wdt_ops = { .owner = THIS_MODULE, .start = wdt_start, .stop = wdt_stop, .ping = wdt_ping, };
static int mid_wdt_probe(struct platform_device *pdev) { struct watchdog_device *wdt_dev; struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data; int ret; if (!pdata) { dev_err(&pdev->dev, "missing platform data\n"); return -EINVAL; } if (pdata->probe) { ret = pdata->probe(pdev); if (ret) return ret; } wdt_dev = devm_kzalloc(&pdev->dev, sizeof(*wdt_dev), GFP_KERNEL); if (!wdt_dev) return -ENOMEM; wdt_dev->info = &mid_wdt_info; wdt_dev->ops = &mid_wdt_ops; wdt_dev->min_timeout = MID_WDT_TIMEOUT_MIN; wdt_dev->max_timeout = MID_WDT_TIMEOUT_MAX; wdt_dev->timeout = MID_WDT_DEFAULT_TIMEOUT; wdt_dev->parent = &pdev->dev; watchdog_set_drvdata(wdt_dev, &pdev->dev); ret = devm_request_irq(&pdev->dev, pdata->irq, mid_wdt_irq, IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog", wdt_dev); if (ret) { dev_err(&pdev->dev, "error requesting warning irq %d\n", pdata->irq); return ret; } /* * The firmware followed by U-Boot leaves the watchdog running * with the default threshold which may vary. When we get here * we should make a decision to prevent any side effects before * user space daemon will take care of it. The best option, * taking into consideration that there is no way to read values * back from hardware, is to enforce watchdog being run with * deterministic values. */ ret = wdt_start(wdt_dev); if (ret) return ret; /* Make sure the watchdog is serviced */ set_bit(WDOG_HW_RUNNING, &wdt_dev->status); ret = devm_watchdog_register_device(&pdev->dev, wdt_dev); if (ret) { dev_err(&pdev->dev, "error registering watchdog device\n"); return ret; } dev_info(&pdev->dev, "Intel MID watchdog device probed\n"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Cohen22984.81%120.00%
Andy Shevchenko269.63%240.00%
Pratyush Anand93.33%120.00%
Guenter Roeck62.22%120.00%
Total270100.00%5100.00%

static struct platform_driver mid_wdt_driver = { .probe = mid_wdt_probe, .driver = { .name = "intel_mid_wdt", }, }; module_platform_driver(mid_wdt_driver); MODULE_AUTHOR("David Cohen <david.a.cohen@linux.intel.com>"); MODULE_DESCRIPTION("Watchdog Driver for Intel MID platform"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
David Cohen60189.17%228.57%
Andy Shevchenko588.61%342.86%
Pratyush Anand91.34%114.29%
Guenter Roeck60.89%114.29%
Total674100.00%7100.00%
Directory: drivers/watchdog
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