diff options
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/max63xx_wdt.c | 397 |
3 files changed, 403 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 1e48d4c45f86..713b1cef37d3 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -55,6 +55,11 @@ config SOFT_WATCHDOG To compile this driver as a module, choose M here: the module will be called softdog. +config MAX63XX_WATCHDOG + tristate "Max63xx watchdog" + help + Support for memory mapped max63{69,70,71,72,73,74} watchdog timer. + config WM831X_WATCHDOG tristate "WM831x watchdog" depends on MFD_WM831X diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2fd15947deb7..5e3cb95bb0e9 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -143,4 +143,5 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o # Architecture Independant obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o +obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c new file mode 100644 index 000000000000..6eb91d757604 --- /dev/null +++ b/drivers/watchdog/max63xx_wdt.c @@ -0,0 +1,397 @@ +/* + * drivers/char/watchdog/max63xx_wdt.c + * + * Driver for max63{69,70,71,72,73,74} watchdog timers + * + * Copyright (C) 2009 Marc Zyngier <maz@misterjones.org> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + * This driver assumes the watchdog pins are memory mapped (as it is + * the case for the Arcom Zeus). Should it be connected over GPIOs or + * another interface, some abstraction will have to be introduced. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/init.h> +#include <linux/bitops.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/device.h> + +#define DEFAULT_HEARTBEAT 60 +#define MAX_HEARTBEAT 60 + +static int heartbeat = DEFAULT_HEARTBEAT; +static int nowayout = WATCHDOG_NOWAYOUT; + +/* + * Memory mapping: a single byte, 3 first lower bits to select bit 3 + * to ping the watchdog. + */ +#define MAX6369_WDSET (7 << 0) +#define MAX6369_WDI (1 << 3) + +static DEFINE_SPINLOCK(io_lock); + +static unsigned long wdt_status; +#define WDT_IN_USE 0 +#define WDT_RUNNING 1 +#define WDT_OK_TO_CLOSE 2 + +static int nodelay; +static struct resource *wdt_mem; +static void __iomem *wdt_base; +static struct platform_device *max63xx_pdev; + +/* + * The timeout values used are actually the absolute minimum the chip + * offers. Typical values on my board are slightly over twice as long + * (10s setting ends up with a 25s timeout), and can be up to 3 times + * the nominal setting (according to the datasheet). So please take + * these values with a grain of salt. Same goes for the initial delay + * "feature". Only max6373/74 have a few settings without this initial + * delay (selected with the "nodelay" parameter). + * + * I also decided to remove from the tables any timeout smaller than a + * second, as it looked completly overkill... + */ + +/* Timeouts in second */ +struct max63xx_timeout { + u8 wdset; + u8 tdelay; + u8 twd; +}; + +static struct max63xx_timeout max6369_table[] = { + { 5, 1, 1 }, + { 6, 10, 10 }, + { 7, 60, 60 }, + { }, +}; + +static struct max63xx_timeout max6371_table[] = { + { 6, 60, 3 }, + { 7, 60, 60 }, + { }, +}; + +static struct max63xx_timeout max6373_table[] = { + { 2, 60, 1 }, + { 5, 0, 1 }, + { 1, 3, 3 }, + { 7, 60, 10 }, + { 6, 0, 10 }, + { }, +}; + +static struct max63xx_timeout *current_timeout; + +static struct max63xx_timeout * +max63xx_select_timeout(struct max63xx_timeout *table, int value) +{ + while (table->twd) { + if (value <= table->twd) { + if (nodelay && table->tdelay == 0) + return table; + + if (!nodelay) + return table; + } + + table++; + } + + return NULL; +} + +static void max63xx_wdt_ping(void) +{ + u8 val; + + spin_lock(&io_lock); + + val = __raw_readb(wdt_base); + + __raw_writeb(val | MAX6369_WDI, wdt_base); + __raw_writeb(val & ~MAX6369_WDI, wdt_base); + + spin_unlock(&io_lock); +} + +static void max63xx_wdt_enable(struct max63xx_timeout *entry) +{ + u8 val; + + if (test_and_set_bit(WDT_RUNNING, &wdt_status)) + return; + + spin_lock(&io_lock); + + val = __raw_readb(wdt_base); + val &= ~MAX6369_WDSET; + val |= entry->wdset; + __raw_writeb(val, wdt_base); + + spin_unlock(&io_lock); + + /* check for a edge triggered startup */ + if (entry->tdelay == 0) + max63xx_wdt_ping(); +} + +static void max63xx_wdt_disable(void) +{ + spin_lock(&io_lock); + + __raw_writeb(3, wdt_base); + + spin_unlock(&io_lock); + + clear_bit(WDT_RUNNING, &wdt_status); +} + +static int max63xx_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(WDT_IN_USE, &wdt_status)) + return -EBUSY; + + max63xx_wdt_enable(current_timeout); + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + + return nonseekable_open(inode, file); +} + +static ssize_t max63xx_wdt_write(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + + if (c == 'V') + set_bit(WDT_OK_TO_CLOSE, &wdt_status); + } + } + + max63xx_wdt_ping(); + } + + return len; +} + +static const struct watchdog_info ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .identity = "max63xx Watchdog", +}; + +static long max63xx_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int ret = -ENOTTY; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user((struct watchdog_info *)arg, &ident, + sizeof(ident)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, (int *)arg); + break; + + case WDIOC_KEEPALIVE: + max63xx_wdt_ping(); + ret = 0; + break; + + case WDIOC_GETTIMEOUT: + ret = put_user(heartbeat, (int *)arg); + break; + } + return ret; +} + +static int max63xx_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) + max63xx_wdt_disable(); + else + dev_crit(&max63xx_pdev->dev, + "device closed unexpectedly - timer will not stop\n"); + + clear_bit(WDT_IN_USE, &wdt_status); + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + + return 0; +} + +static const struct file_operations max63xx_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = max63xx_wdt_write, + .unlocked_ioctl = max63xx_wdt_ioctl, + .open = max63xx_wdt_open, + .release = max63xx_wdt_release, +}; + +static struct miscdevice max63xx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &max63xx_wdt_fops, +}; + +static int __devinit max63xx_wdt_probe(struct platform_device *pdev) +{ + int ret = 0; + int size; + struct resource *res; + struct device *dev = &pdev->dev; + struct max63xx_timeout *table; + + table = (struct max63xx_timeout *)pdev->id_entry->driver_data; + + if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) + heartbeat = DEFAULT_HEARTBEAT; + + dev_info(dev, "requesting %ds heartbeat\n", heartbeat); + current_timeout = max63xx_select_timeout(table, heartbeat); + + if (!current_timeout) { + dev_err(dev, "unable to satisfy heartbeat request\n"); + return -EINVAL; + } + + dev_info(dev, "using %ds heartbeat with %ds initial delay\n", + current_timeout->twd, current_timeout->tdelay); + + heartbeat = current_timeout->twd; + + max63xx_pdev = pdev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(dev, "failed to get memory region resource\n"); + return -ENOENT; + } + + size = resource_size(res); + wdt_mem = request_mem_region(res->start, size, pdev->name); + + if (wdt_mem == NULL) { + dev_err(dev, "failed to get memory region\n"); + return -ENOENT; + } + + wdt_base = ioremap(res->start, size); + if (!wdt_base) { + dev_err(dev, "failed to map memory region\n"); + ret = -ENOMEM; + goto out_request; + } + + ret = misc_register(&max63xx_wdt_miscdev); + if (ret < 0) { + dev_err(dev, "cannot register misc device\n"); + goto out_unmap; + } + + return 0; + +out_unmap: + iounmap(wdt_base); +out_request: + release_resource(wdt_mem); + kfree(wdt_mem); + + return ret; +} + +static int __devexit max63xx_wdt_remove(struct platform_device *pdev) +{ + misc_deregister(&max63xx_wdt_miscdev); + if (wdt_mem) { + release_resource(wdt_mem); + kfree(wdt_mem); + wdt_mem = NULL; + } + + if (wdt_base) + iounmap(wdt_base); + + return 0; +} + +static struct platform_device_id max63xx_id_table[] = { + { "max6369_wdt", (kernel_ulong_t)max6369_table, }, + { "max6370_wdt", (kernel_ulong_t)max6369_table, }, + { "max6371_wdt", (kernel_ulong_t)max6371_table, }, + { "max6372_wdt", (kernel_ulong_t)max6371_table, }, + { "max6373_wdt", (kernel_ulong_t)max6373_table, }, + { "max6374_wdt", (kernel_ulong_t)max6373_table, }, + { }, +}; +MODULE_DEVICE_TABLE(platform, max63xx_id_table); + +static struct platform_driver max63xx_wdt_driver = { + .probe = max63xx_wdt_probe, + .remove = __devexit_p(max63xx_wdt_remove), + .id_table = max63xx_id_table, + .driver = { + .name = "max63xx_wdt", + .owner = THIS_MODULE, + }, +}; + +static int __init max63xx_wdt_init(void) +{ + return platform_driver_register(&max63xx_wdt_driver); +} + +static void __exit max63xx_wdt_exit(void) +{ + platform_driver_unregister(&max63xx_wdt_driver); +} + +module_init(max63xx_wdt_init); +module_exit(max63xx_wdt_exit); + +MODULE_AUTHOR("Marc Zyngier <maz@misterjones.org>"); +MODULE_DESCRIPTION("max63xx Watchdog Driver"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, + "Watchdog heartbeat period in seconds from 1 to " + __MODULE_STRING(MAX_HEARTBEAT) ", default " + __MODULE_STRING(DEFAULT_HEARTBEAT)); + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +module_param(nodelay, int, 0); +MODULE_PARM_DESC(nodelay, + "Force selection of a timeout setting without initial delay " + "(max6373/74 only, default=0)"); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
