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author | Sean MacLennan <smaclennan@pikatech.com> | 2008-09-23 20:26:26 -0400 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2009-01-12 20:08:56 +0000 |
commit | 618efba999d0e7f4bcde93231dcb9a748223c6e3 (patch) | |
tree | fca1195611b8c7f272cf0cd947e99062fa0748bb | |
parent | 6ec9eae67a82a38865af20580e5e0ccd012aca4b (diff) | |
download | kernel_samsung_espresso10-618efba999d0e7f4bcde93231dcb9a748223c6e3.zip kernel_samsung_espresso10-618efba999d0e7f4bcde93231dcb9a748223c6e3.tar.gz kernel_samsung_espresso10-618efba999d0e7f4bcde93231dcb9a748223c6e3.tar.bz2 |
[WATCHDOG] Pika Warp appliance watchdog timer
The FPGA based watchdog timer used by the Pika Warp appliance.
Signed-off-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
-rw-r--r-- | drivers/watchdog/Kconfig | 8 | ||||
-rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
-rw-r--r-- | drivers/watchdog/pika_wdt.c | 301 |
3 files changed, 310 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index d55d315..3efa12f 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -796,6 +796,14 @@ config MV64X60_WDT tristate "MV64X60 (Marvell Discovery) Watchdog Timer" depends on MV64X60 +config PIKA_WDT + tristate "PIKA FPGA Watchdog" + depends on WARP + default y + help + This enables the watchdog in the PIKA FPGA. Currently used on + the Warp platform. + config BOOKE_WDT bool "PowerPC Book-E Watchdog Timer" depends on BOOKE || 4xx diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index e79187a..806b3eb 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -115,6 +115,7 @@ obj-$(CONFIG_GEF_WDT) += gef_wdt.o obj-$(CONFIG_MPC5200_WDT) += mpc5200_wdt.o obj-$(CONFIG_8xxx_WDT) += mpc8xxx_wdt.o obj-$(CONFIG_MV64X60_WDT) += mv64x60_wdt.o +obj-$(CONFIG_PIKA_WDT) += pika_wdt.o obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o # PPC64 Architecture diff --git a/drivers/watchdog/pika_wdt.c b/drivers/watchdog/pika_wdt.c new file mode 100644 index 0000000..2d22e99 --- /dev/null +++ b/drivers/watchdog/pika_wdt.c @@ -0,0 +1,301 @@ +/* + * PIKA FPGA based Watchdog Timer + * + * Copyright (c) 2008 PIKA Technologies + * Sean MacLennan <smaclennan@pikatech.com> + */ + +#include <linux/init.h> +#include <linux/errno.h> +#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/reboot.h> +#include <linux/jiffies.h> +#include <linux/timer.h> +#include <linux/bitops.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/of_platform.h> + +#define DRV_NAME "PIKA-WDT" +#define PFX DRV_NAME ": " + +/* Hardware timeout in seconds */ +#define WDT_HW_TIMEOUT 2 + +/* Timer heartbeat (500ms) */ +#define WDT_TIMEOUT (HZ/2) + +/* User land timeout */ +#define WDT_HEARTBEAT 15 +static int heartbeat = WDT_HEARTBEAT; +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. " + "(default = " __MODULE_STRING(WDT_HEARTBEAT) ")"); + +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 struct { + void __iomem *fpga; + unsigned long next_heartbeat; /* the next_heartbeat for the timer */ + unsigned long open; + char expect_close; + int bootstatus; + struct timer_list timer; /* The timer that pings the watchdog */ +} pikawdt_private; + +static struct watchdog_info ident = { + .identity = DRV_NAME, + .options = WDIOF_CARDRESET | + WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +/* + * Reload the watchdog timer. (ie, pat the watchdog) + */ +static inline void pikawdt_reset(void) +{ + /* -- FPGA: Reset Control Register (32bit R/W) (Offset: 0x14) -- + * Bit 7, WTCHDG_EN: When set to 1, the watchdog timer is enabled. + * Once enabled, it cannot be disabled. The watchdog can be + * kicked by performing any write access to the reset + * control register (this register). + * Bit 8-11, WTCHDG_TIMEOUT_SEC: Sets the watchdog timeout value in + * seconds. Valid ranges are 1 to 15 seconds. The value can + * be modified dynamically. + */ + unsigned reset = in_be32(pikawdt_private.fpga + 0x14); + /* enable with max timeout - 15 seconds */ + reset |= (1 << 7) + (WDT_HW_TIMEOUT << 8); + out_be32(pikawdt_private.fpga + 0x14, reset); +} + +/* + * Timer tick + */ +static void pikawdt_ping(unsigned long data) +{ + if (time_before(jiffies, pikawdt_private.next_heartbeat) || + (!nowayout && !pikawdt_private.open)) { + pikawdt_reset(); + mod_timer(&pikawdt_private.timer, jiffies + WDT_TIMEOUT); + } else + printk(KERN_CRIT PFX "I will reset your machine !\n"); +} + + +static void pikawdt_keepalive(void) +{ + pikawdt_private.next_heartbeat = jiffies + heartbeat * HZ; +} + +static void pikawdt_start(void) +{ + pikawdt_keepalive(); + mod_timer(&pikawdt_private.timer, jiffies + WDT_TIMEOUT); +} + +/* + * Watchdog device is opened, and watchdog starts running. + */ +static int pikawdt_open(struct inode *inode, struct file *file) +{ + /* /dev/watchdog can only be opened once */ + if (test_and_set_bit(0, &pikawdt_private.open)) + return -EBUSY; + + pikawdt_start(); + + return nonseekable_open(inode, file); +} + +/* + * Close the watchdog device. + */ +static int pikawdt_release(struct inode *inode, struct file *file) +{ + /* stop internal ping */ + if (!pikawdt_private.expect_close) + del_timer(&pikawdt_private.timer); + + clear_bit(0, &pikawdt_private.open); + pikawdt_private.expect_close = 0; + return 0; +} + +/* + * Pat the watchdog whenever device is written to. + */ +static ssize_t pikawdt_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + if (!len) + return 0; + + /* Scan for magic character */ + if (!nowayout) { + size_t i; + + pikawdt_private.expect_close = 0; + + for (i = 0; i < len; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') { + pikawdt_private.expect_close = 42; + break; + } + } + } + + pikawdt_keepalive(); + + return len; +} + +/* + * Handle commands from user-space. + */ +static long pikawdt_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int new_value; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + return put_user(0, p); + + case WDIOC_GETBOOTSTATUS: + return put_user(pikawdt_private.bootstatus, p); + + case WDIOC_KEEPALIVE: + pikawdt_keepalive(); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_value, p)) + return -EFAULT; + + heartbeat = new_value; + pikawdt_keepalive(); + + return put_user(new_value, p); /* return current value */ + + case WDIOC_GETTIMEOUT: + return put_user(heartbeat, p); + } + return -ENOTTY; +} + + +static const struct file_operations pikawdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .open = pikawdt_open, + .release = pikawdt_release, + .write = pikawdt_write, + .unlocked_ioctl = pikawdt_ioctl, +}; + +static struct miscdevice pikawdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &pikawdt_fops, +}; + +static int __init pikawdt_init(void) +{ + struct device_node *np; + void __iomem *fpga; + static u32 post1; + int ret; + + np = of_find_compatible_node(NULL, NULL, "pika,fpga"); + if (np == NULL) { + printk(KERN_ERR PFX "Unable to find fpga.\n"); + return -ENOENT; + } + + pikawdt_private.fpga = of_iomap(np, 0); + of_node_put(np); + if (pikawdt_private.fpga == NULL) { + printk(KERN_ERR PFX "Unable to map fpga.\n"); + return -ENOMEM; + } + + ident.firmware_version = in_be32(pikawdt_private.fpga + 0x1c) & 0xffff; + + /* POST information is in the sd area. */ + np = of_find_compatible_node(NULL, NULL, "pika,fpga-sd"); + if (np == NULL) { + printk(KERN_ERR PFX "Unable to find fpga-sd.\n"); + ret = -ENOENT; + goto out; + } + + fpga = of_iomap(np, 0); + of_node_put(np); + if (fpga == NULL) { + printk(KERN_ERR PFX "Unable to map fpga-sd.\n"); + ret = -ENOMEM; + goto out; + } + + /* -- FPGA: POST Test Results Register 1 (32bit R/W) (Offset: 0x4040) -- + * Bit 31, WDOG: Set to 1 when the last reset was caused by a watchdog + * timeout. + */ + post1 = in_be32(fpga + 0x40); + if (post1 & 0x80000000) + pikawdt_private.bootstatus = WDIOF_CARDRESET; + + iounmap(fpga); + + setup_timer(&pikawdt_private.timer, pikawdt_ping, 0); + + ret = misc_register(&pikawdt_miscdev); + if (ret) { + printk(KERN_ERR PFX "Unable to register miscdev.\n"); + goto out; + } + + printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n", + heartbeat, nowayout); + return 0; + +out: + iounmap(pikawdt_private.fpga); + return ret; +} + +static void __exit pikawdt_exit(void) +{ + misc_deregister(&pikawdt_miscdev); + + iounmap(pikawdt_private.fpga); +} + +module_init(pikawdt_init); +module_exit(pikawdt_exit); + +MODULE_AUTHOR("Sean MacLennan <smaclennan@pikatech.com>"); +MODULE_DESCRIPTION("PIKA FPGA based Watchdog Timer"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + |