From: Graeme Gregory <[email protected]> Add support for the Palmas watchdog timer which has a timeout configurable from 1s to 128s.
Signed-off-by: Graeme Gregory <[email protected]> Signed-off-by: Ian Lartey <[email protected]> --- drivers/watchdog/palmas_wdt.c | 291 +++++++++++++++++++++++++++++++++++++++++ 1 files changed, 291 insertions(+), 0 deletions(-) create mode 100644 drivers/watchdog/palmas_wdt.c diff --git a/drivers/watchdog/palmas_wdt.c b/drivers/watchdog/palmas_wdt.c new file mode 100644 index 0000000..68cdc1e --- /dev/null +++ b/drivers/watchdog/palmas_wdt.c @@ -0,0 +1,291 @@ +/* + * Driver for Watchdog part of Palmas PMIC Chips + * + * Copyright 2011 Texas Instruments Inc. + * + * Author: Graeme Gregory <[email protected]> + * Author: Ian Lartey <[email protected]> + * + * Based on twl4030_wdt.c + * + * Author: Timo Kokkonen <timo.t.kokkonen at nokia.com> + * + * 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. + * + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> +#include <linux/miscdevice.h> +#include <linux/uaccess.h> +#include <linux/mfd/palmas.h> + +static struct platform_device *palmas_wdt_dev; + +struct palmas_wdt { + struct palmas *palmas; + + struct miscdevice miscdev; + int timer_margin; + unsigned long state; +}; + +#define PALMAS_WDT_ENABLED (1<<1) + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static int palmas_wdt_write(struct palmas *palmas, unsigned int data) +{ + unsigned int addr; + + addr = PALMAS_BASE_TO_REG(PALMAS_PMU_CONTROL_BASE, PALMAS_WATCHDOG); + + return palmas_write(palmas, PALMAS_PMU_CONTROL_BASE, addr, addr); +} + +static int palmas_wdt_enable(struct palmas_wdt *wdt) +{ + return palmas_wdt_write(wdt->palmas, + wdt->timer_margin | PALMAS_WATCHDOG_ENABLE); +} + +static int palmas_wdt_disable(struct palmas_wdt *wdt) +{ + return palmas_wdt_write(wdt->palmas, wdt->timer_margin); +} + +static int palmas_wdt_set_timeout(struct palmas_wdt *wdt, int timeout) +{ + if (timeout < 1 || timeout > 128) { + dev_warn(wdt->miscdev.parent, + "Timeout can only be in the range [1-128] seconds"); + return -EINVAL; + } + wdt->timer_margin = fls(timeout) - 1; + return palmas_wdt_enable(wdt); +} + +static ssize_t palmas_wdt_write_fop(struct file *file, + const char __user *data, size_t len, loff_t *ppos) +{ + struct palmas_wdt *wdt = file->private_data; + + if (len) + palmas_wdt_enable(wdt); + + return len; +} + +static long palmas_wdt_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int new_margin; + struct palmas_wdt *wdt = file->private_data; + int time = 0; + + static const struct watchdog_info palmas_wd_ident = { + .identity = "Palmas Watchdog", + .options = WDIOF_SETTIMEOUT, + .firmware_version = 0, + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &palmas_wd_ident, + sizeof(palmas_wd_ident)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + + case WDIOC_KEEPALIVE: + palmas_wdt_enable(wdt); + break; + + case WDIOC_SETTIMEOUT: + if (get_user(new_margin, p)) + return -EFAULT; + if (palmas_wdt_set_timeout(wdt, new_margin)) + return -EINVAL; + + time = 1 << wdt->timer_margin; + + return put_user(time, p); + + case WDIOC_GETTIMEOUT: + time = 1 << wdt->timer_margin; + + return put_user(time, p); + + default: + return -ENOTTY; + } + + return 0; +} + +static int palmas_wdt_open(struct inode *inode, struct file *file) +{ + struct palmas_wdt *wdt = platform_get_drvdata(palmas_wdt_dev); + + /* /dev/watchdog can only be opened once */ + if (test_and_set_bit(0, &wdt->state)) + return -EBUSY; + + wdt->state |= PALMAS_WDT_ENABLED; + file->private_data = (void *) wdt; + + palmas_wdt_enable(wdt); + return nonseekable_open(inode, file); +} + +static int palmas_wdt_release(struct inode *inode, struct file *file) +{ + struct palmas_wdt *wdt = file->private_data; + if (nowayout) { + dev_alert(wdt->miscdev.parent, + "Unexpected close, watchdog still running!\n"); + palmas_wdt_enable(wdt); + } else { + if (palmas_wdt_disable(wdt)) + return -EFAULT; + wdt->state &= ~PALMAS_WDT_ENABLED; + } + + clear_bit(0, &wdt->state); + return 0; +} + +static const struct file_operations palmas_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .open = palmas_wdt_open, + .release = palmas_wdt_release, + .unlocked_ioctl = palmas_wdt_ioctl, + .write = palmas_wdt_write_fop, +}; + +static int palmas_wdt_probe(struct platform_device *pdev) +{ + struct palmas *palmas = dev_get_drvdata(pdev->dev.parent); + struct palmas_wdt *wdt; + int ret = 0; + + wdt = kzalloc(sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->palmas = palmas; + wdt->state = 0; + wdt->timer_margin = 7; + wdt->miscdev.parent = &pdev->dev; + wdt->miscdev.fops = &palmas_wdt_fops; + wdt->miscdev.minor = WATCHDOG_MINOR; + wdt->miscdev.name = "watchdog"; + + platform_set_drvdata(pdev, wdt); + + palmas_wdt_dev = pdev; + + palmas_wdt_disable(wdt); + + ret = misc_register(&wdt->miscdev); + if (ret) { + dev_err(wdt->miscdev.parent, + "Failed to register misc device\n"); + platform_set_drvdata(pdev, NULL); + kfree(wdt); + palmas_wdt_dev = NULL; + return ret; + } + return 0; +} + +static int palmas_wdt_remove(struct platform_device *pdev) +{ + struct palmas_wdt *wdt = platform_get_drvdata(pdev); + + if (wdt->state & PALMAS_WDT_ENABLED) + if (palmas_wdt_disable(wdt)) + return -EFAULT; + + wdt->state &= ~PALMAS_WDT_ENABLED; + misc_deregister(&wdt->miscdev); + + platform_set_drvdata(pdev, NULL); + kfree(wdt); + palmas_wdt_dev = NULL; + + return 0; +} + +#ifdef CONFIG_PM +static int palmas_wdt_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct palmas_wdt *wdt = platform_get_drvdata(pdev); + if (wdt->state & PALMAS_WDT_ENABLED) + return palmas_wdt_disable(wdt); + + return 0; +} + +static int palmas_wdt_resume(struct platform_device *pdev) +{ + struct palmas_wdt *wdt = platform_get_drvdata(pdev); + if (wdt->state & PALMAS_WDT_ENABLED) + return palmas_wdt_enable(wdt); + + return 0; +} +#else +#define palmas_wdt_suspend NULL +#define palmas_wdt_resume NULL +#endif + +static struct of_device_id of_palmas_match_tbl[] = { + { .compatible = "ti,palmas-wdt", }, + { /* end */ } +}; + +static struct platform_driver palmas_wdt_driver = { + .probe = palmas_wdt_probe, + .remove = palmas_wdt_remove, + .suspend = palmas_wdt_suspend, + .resume = palmas_wdt_resume, + .driver = { + .owner = THIS_MODULE, + .of_match_table = of_palmas_match_tbl, + .name = "palmas-wdt", + }, +}; + +static int palmas_wdt_init(void) +{ + return platform_driver_register(&palmas_wdt_driver); +} +module_init(palmas_wdt_init); + +static void palmas_wdt_exit(void) +{ + platform_driver_unregister(&palmas_wdt_driver); +} +module_exit(palmas_wdt_exit); + +MODULE_AUTHOR("Graeme Gregory <[email protected]>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:palmas-wdt"); +MODULE_DEVICE_TABLE(of, of_palmas_match_tbl); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
