intel-mid_wdt.rar_generic

/* * 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 <[email protected]> * * 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); } static int wdt_start(struct watchdog_device *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) { struct device *dev = watchdog_get_drvdata(wd); dev_crit(dev, "error starting watchdog: %d\n", ret); } return ret; } static int wdt_ping(struct watchdog_device *wd) { int ret; ret = wdt_command(SCU_WATCHDOG_KEEPALIVE, NULL, 0); if (ret) { struct device *dev = watchdog_get_drvdata(wd); dev_crit(dev, "Error executing keepalive: 0x%x\n", ret); } return ret; } static int wdt_stop(struct watchdog_device *wd) { int ret; ret = wdt_command(SCU_WATCHDOG_STOP, NULL, 0); if (ret) { struct device *dev = watchdog_get_drvdata(wd); dev_crit(dev, "Error stopping watchdog: 0x%x\n", ret); } return ret; } static irqreturn_t mid_wdt_irq(int irq, void *dev_id) { panic("Kernel Watchdog"); /* This code should not be reached */ return IRQ_HANDLED; } static const struct watchdog_info mid_wdt_info = { .identity = "Intel MID SCU watchdog", .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, }; 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; watchdog_set_drvdata(wdt_dev, &pdev->dev); platform_set_drvdata(pdev, wdt_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; } ret = watchdog_register_device(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; } static int mid_wdt_remove(struct platform_device *pdev) { struct watchdog_device *wd = platform_get_drvdata(pdev); watchdog_unregister_device(wd); return 0; } static struct platform_driver mid_wdt_driver = { .probe = mid_wdt_probe, .remove = mid_wdt_remove, .driver = { .name = "intel_mid_wdt", }, }; module_platform_driver(mid_wdt_driver); MODULE_AUTHOR("David Cohen <[email protected]>"); MODULE_DESCRIPTION("Watchdog Driver for Intel MID platform"); MODULE_LICENSE("GPL");