From: Gary King Date: Thu, 26 Aug 2010 17:59:50 +0000 (-0700) Subject: watchdog: add tegra_wdt driver X-Git-Tag: firefly_0821_release~9833^2~242 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2b3a85e0785ecb20d764d04109bf707de4a99892;p=firefly-linux-kernel-4.4.55.git watchdog: add tegra_wdt driver add a driver for the hardware watchdog timer embedded in NVIDIA Tegra SoCs Change-Id: I45bc829f26f350143d5a07e1f4ddc46d24f3a54c Signed-off-by: Gary King --- diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 24efd8ea41bb..1addd785739a 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -195,6 +195,17 @@ config MPCORE_WATCHDOG To compile this driver as a module, choose M here: the module will be called mpcore_wdt. +config TEGRA_WATCHDOG + tristate "Tegra watchdog" + depends on ARCH_TEGRA + help + Say Y here to include support for the watchdog timer + embedded in NVIDIA Tegra SoCs. + + To compile this driver as a module, choose M here: the + module will be called tegra_wdt. + + config EP93XX_WATCHDOG tristate "EP93xx Watchdog" depends on ARCH_EP93XX diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 8374503fcc6a..62d90bee8dbe 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o +obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o diff --git a/drivers/watchdog/tegra_wdt.c b/drivers/watchdog/tegra_wdt.c new file mode 100644 index 000000000000..d7a9d7609a1f --- /dev/null +++ b/drivers/watchdog/tegra_wdt.c @@ -0,0 +1,381 @@ +/* + * drivers/watchdog/tegra_wdt.c + * + * watchdog driver for NVIDIA tegra internal watchdog + * + * Copyright (c) 2010, NVIDIA Corporation. + * + * based on drivers/watchdog/softdog.c and drivers/watchdog/omap_wdt.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* minimum and maximum watchdog trigger periods, in seconds */ +#define MIN_WDT_PERIOD 5 +#define MAX_WDT_PERIOD 1000 + +#define TIMER_PTV 0x0 + #define TIMER_EN (1 << 31) + #define TIMER_PERIODIC (1 << 30) + +#define TIMER_PCR 0x4 + #define TIMER_PCR_INTR (1 << 30) + +#define WDT_EN (1 << 5) +#define WDT_SEL_TMR1 (0 << 4) +#define WDT_SYS_RST (1 << 2) + +static int heartbeat = 60; + +struct tegra_wdt { + struct miscdevice miscdev; + struct notifier_block notifier; + struct resource *res_src; + struct resource *res_wdt; + unsigned long users; + void __iomem *wdt_source; + void __iomem *wdt_timer; + int irq; + int timeout; + bool enabled; +}; + +static struct tegra_wdt *tegra_wdt_dev; + +static void tegra_wdt_set_timeout(struct tegra_wdt *wdt, int sec) +{ + u32 ptv, src; + + ptv = readl(wdt->wdt_timer + TIMER_PTV); + src = readl(wdt->wdt_source); + + writel(0, wdt->wdt_source); + wdt->timeout = clamp(sec, MIN_WDT_PERIOD, MAX_WDT_PERIOD); + if (ptv & TIMER_EN) { + /* since the watchdog reset occurs when a second interrupt + * is asserted before the first is processed, program the + * timer period to one-half of the watchdog period */ + ptv = wdt->timeout * 1000000ul / 2; + ptv |= (TIMER_EN | TIMER_PERIODIC); + writel(ptv, wdt->wdt_timer + TIMER_PTV); + } + writel(src, wdt->wdt_source); +} + + +static void tegra_wdt_enable(struct tegra_wdt *wdt) +{ + u32 val; + + val = wdt->timeout * 1000000ul / 2; + val |= (TIMER_EN | TIMER_PERIODIC); + writel(val, wdt->wdt_timer + TIMER_PTV); + + val = WDT_EN | WDT_SEL_TMR1 | WDT_SYS_RST; + writel(val, wdt->wdt_source); +} + +static void tegra_wdt_disable(struct tegra_wdt *wdt) +{ + writel(0, wdt->wdt_source); + writel(0, wdt->wdt_timer + TIMER_PTV); +} + +static irqreturn_t tegra_wdt_interrupt(int irq, void *dev_id) +{ + struct tegra_wdt *wdt = dev_id; + + writel(TIMER_PCR_INTR, wdt->wdt_timer + TIMER_PCR); + return IRQ_HANDLED; +} + +static int tegra_wdt_notify(struct notifier_block *this, + unsigned long code, void *dev) +{ + struct tegra_wdt *wdt = container_of(this, struct tegra_wdt, notifier); + + if (code == SYS_DOWN || code == SYS_HALT) + tegra_wdt_disable(wdt); + return NOTIFY_DONE; +} + +static int tegra_wdt_open(struct inode *inode, struct file *file) +{ + struct miscdevice *miscdev = file->private_data; + struct tegra_wdt *wdt = dev_get_drvdata(miscdev->parent); + + if (test_and_set_bit(1, &wdt->users)) + return -EBUSY; + + wdt->enabled = true; + tegra_wdt_set_timeout(wdt, heartbeat); + tegra_wdt_enable(wdt); + file->private_data = wdt; + return nonseekable_open(inode, file); +} + +static int tegra_wdt_release(struct inode *inode, struct file *file) +{ + struct tegra_wdt *wdt = file->private_data; + +#ifndef CONFIG_WATCHDOG_NOWAYOUT + tegra_wdt_disable(wdt); + wdt->enabled = false; +#endif + wdt->users = 0; + return 0; +} + +static long tegra_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct tegra_wdt *wdt = file->private_data; + static DEFINE_SPINLOCK(lock); + int new_timeout; + static const struct watchdog_info ident = { + .identity = "Tegra Watchdog", + .options = WDIOF_SETTIMEOUT, + .firmware_version = 0, + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user((struct watchdog_info __user *)arg, &ident, + sizeof(ident)); + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, (int __user *)arg); + + case WDIOC_KEEPALIVE: + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, (int __user *)arg)) + return -EFAULT; + spin_lock(&lock); + tegra_wdt_disable(wdt); + tegra_wdt_set_timeout(wdt, new_timeout); + tegra_wdt_enable(wdt); + spin_unlock(&lock); + case WDIOC_GETTIMEOUT: + return put_user(wdt->timeout, (int __user *)arg); + default: + return -ENOTTY; + } +} + +static ssize_t tegra_wdt_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + return len; +} + +static const struct file_operations tegra_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = tegra_wdt_write, + .unlocked_ioctl = tegra_wdt_ioctl, + .open = tegra_wdt_open, + .release = tegra_wdt_release, +}; + +static int tegra_wdt_probe(struct platform_device *pdev) +{ + struct resource *res_src, *res_wdt, *res_irq; + struct tegra_wdt *wdt; + int ret = 0; + + if (pdev->id != -1) { + dev_err(&pdev->dev, "only id -1 supported\n"); + return -ENODEV; + } + + if (tegra_wdt_dev != NULL) { + dev_err(&pdev->dev, "watchdog already registered\n"); + return -EIO; + } + + res_src = platform_get_resource(pdev, IORESOURCE_MEM, 0); + res_wdt = platform_get_resource(pdev, IORESOURCE_MEM, 1); + res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + + if (!res_src || !res_wdt || !res_irq) { + dev_err(&pdev->dev, "incorrect resources\n"); + return -ENOENT; + } + + wdt = kzalloc(sizeof(*wdt), GFP_KERNEL); + if (!wdt) { + dev_err(&pdev->dev, "out of memory\n"); + return -ENOMEM; + } + + wdt->irq = -1; + wdt->miscdev.parent = &pdev->dev; + wdt->miscdev.minor = WATCHDOG_MINOR; + wdt->miscdev.name = "watchdog"; + wdt->miscdev.fops = &tegra_wdt_fops; + + wdt->notifier.notifier_call = tegra_wdt_notify; + + res_src = request_mem_region(res_src->start, resource_size(res_src), + pdev->name); + res_wdt = request_mem_region(res_wdt->start, resource_size(res_wdt), + pdev->name); + + if (!res_src || !res_wdt) { + dev_err(&pdev->dev, "unable to request memory resources\n"); + ret = -EBUSY; + goto fail; + } + + wdt->wdt_source = ioremap(res_src->start, resource_size(res_src)); + wdt->wdt_timer = ioremap(res_wdt->start, resource_size(res_wdt)); + if (!wdt->wdt_source || !wdt->wdt_timer) { + dev_err(&pdev->dev, "unable to map registers\n"); + ret = -ENOMEM; + goto fail; + } + + tegra_wdt_disable(wdt); + + ret = request_irq(res_irq->start, tegra_wdt_interrupt, IRQF_DISABLED, + dev_name(&pdev->dev), wdt); + if (ret) { + dev_err(&pdev->dev, "unable to configure IRQ\n"); + goto fail; + } + + wdt->irq = res_irq->start; + wdt->res_src = res_src; + wdt->res_wdt = res_wdt; + + wdt->timeout = heartbeat; + + ret = register_reboot_notifier(&wdt->notifier); + if (ret) { + dev_err(&pdev->dev, "cannot register reboot notifier\n"); + goto fail; + } + + ret = misc_register(&wdt->miscdev); + if (ret) { + dev_err(&pdev->dev, "failed to register misc device\n"); + unregister_reboot_notifier(&wdt->notifier); + goto fail; + } + + platform_set_drvdata(pdev, wdt); + tegra_wdt_dev = wdt; + return 0; +fail: + if (wdt->irq != -1) + free_irq(wdt->irq, wdt); + if (wdt->wdt_source) + iounmap(wdt->wdt_source); + if (wdt->wdt_timer) + iounmap(wdt->wdt_timer); + if (res_src) + release_mem_region(res_src->start, resource_size(res_src)); + if (res_wdt) + release_mem_region(res_wdt->start, resource_size(res_wdt)); + kfree(wdt); + return ret; +} + +static int tegra_wdt_remove(struct platform_device *pdev) +{ + struct tegra_wdt *wdt = platform_get_drvdata(pdev); + + tegra_wdt_disable(wdt); + + unregister_reboot_notifier(&wdt->notifier); + misc_deregister(&wdt->miscdev); + free_irq(wdt->irq, wdt); + iounmap(wdt->wdt_source); + iounmap(wdt->wdt_timer); + release_mem_region(wdt->res_src->start, resource_size(wdt->res_src)); + release_mem_region(wdt->res_wdt->start, resource_size(wdt->res_wdt)); + kfree(wdt); + tegra_wdt_dev = NULL; + return 0; +} + +static int tegra_wdt_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct tegra_wdt *wdt = platform_get_drvdata(pdev); + + tegra_wdt_disable(wdt); + return 0; +} + +static int tegra_wdt_resume(struct platform_device *pdev) +{ + struct tegra_wdt *wdt = platform_get_drvdata(pdev); + + if (wdt->enabled) + tegra_wdt_enable(wdt); + + return 0; +} + +static struct platform_driver tegra_wdt_driver = { + .probe = tegra_wdt_probe, + .remove = __devexit_p(tegra_wdt_remove), + .suspend = tegra_wdt_suspend, + .resume = tegra_wdt_resume, + .driver = { + .owner = THIS_MODULE, + .name = "tegra_wdt", + }, +}; + +static int __init tegra_wdt_init(void) +{ + return platform_driver_register(&tegra_wdt_driver); +} + +static void __exit tegra_wdt_exit(void) +{ + platform_driver_unregister(&tegra_wdt_driver); +} + +module_init(tegra_wdt_init); +module_exit(tegra_wdt_exit); + +MODULE_AUTHOR("NVIDIA Corporation"); +MODULE_DESCRIPTION("Tegra Watchdog Driver"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, + "Watchdog heartbeat period in seconds"); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:tegra_wdt"); +